Commit Graph

549 Commits

Author SHA1 Message Date
Vineet Gupta a150b085b6 ARCv2: boot report CCMs (Closely Coupled Memories)
- ARCv2 uses a seperate BCR for {I,D}CCM base address:
  ARCompact encoded both base/size in same BCR

- Size encoding in common BCR is different for ARCompact/ARCv2

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-18 17:30:18 +05:30
Vineet Gupta 98341f7dc9 ARCv2: boot print Low Latency Memory
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-18 17:30:17 +05:30
Vineet Gupta 0eca6fdb31 ARC: Assume multiplier is always present
It is unlikely that designs running Linux will not have multiplier.
Further the current support is not complete as tool don't generate a
multilib w/o multiplier.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-18 17:30:03 +05:30
Linus Torvalds e835a65f7a ARC fixes for 4.5
- Corner case of returning to delay slot from interrupt
 - Changing default interrupt prioiry level
 - Kconfig'ize support for super pages
 - Other minor fixes
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Merge tag 'arc-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:
 "I've been sitting on some of these fixes for a while.

   - Corner case of returning to delay slot from interrupt
   - Changing default interrupt prioiry level
   - Kconfig'ize support for super pages
   - Other minor fixes"

* tag 'arc-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: mm: Introduce explicit super page size support
  ARCv2: intc: Allow interruption by lowest priority interrupt
  ARCv2: Check for LL-SC livelock only if LLSC is enabled
  ARC: shrink cpuinfo by not saving full timer BCR
  ARCv2: clocksource: Rename GRTC -> GFRC ...
  ARCv2: STAR 9000950267: Handle return from intr to Delay Slot #2
2016-02-13 08:18:21 -08:00
Vineet Gupta dec2b2849c ARCv2: intc: Allow interruption by lowest priority interrupt
ARC HS Cores support configurable multiple interrupt priorities of upto
16 levels.

There is processor "interrupt preemption threshhold" in STATUS32.E[4:1]
And several places need to set this up:
1. seed value as kernel is booting
2. seed value for user space programs
3. Arg to SLEEP instruction in idle task (what interrupt prio can wake)
4. Per-IRQ line prioirty (i.e. what is the priority of interrupt
   raised by a peripheral or timer or perf counter...

Currently above sites use the highest priority 0. This can be potential
problem when multiple priorities are supported. e.g. user space could
only be interrupted by P0 interrupt, not others...
So turn this over and instead make default interruption level to be
the lowest priority possible 15. This should be fine even if there are
fewer priority levels configured (say two: P0 HIGH, P1 LOW)

This feature also effectively disables FIRQ feature if present in
hardware config. With old code, a P0 interrupt would be FIRQ, needing
special handling (ISR or Register Banks) which is NOT supported yet.
Now it not be P0 (P15 or whatever is lowest prio) so FIRQ is not
triggered.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-02-10 06:38:50 +05:30
Vineet Gupta 4d0cb15fcc ARCv2: Check for LL-SC livelock only if LLSC is enabled
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-29 16:51:04 +05:30
Vineet Gupta b89bd1f4fb ARC: shrink cpuinfo by not saving full timer BCR
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-29 16:51:03 +05:30
Vineet Gupta d584f0fb04 ARCv2: clocksource: Rename GRTC -> GFRC ...
... it is now called Global Free Running Counter

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-29 16:51:02 +05:30
Vineet Gupta cbfe74a753 ARCv2: STAR 9000950267: Handle return from intr to Delay Slot #2
Returning to delay slot, riding an interrupti, had one loose end.
AUX_USER_SP used for restoring user mode SP upon RTIE was not being
setup from orig task's saved value, causing task to use wrong SP,
leading to ProtV errors.

The reason being:
 - INTERRUPT_EPILOGUE returns to a kernel trampoline, thus not expected to restore it
 - EXCEPTION_EPILOGUE is not used at all

Fix that by restoring AUX_USER_SP explicitly in the trampoline.

This was broken in the original workaround, but the error scenarios got
reduced considerably since v3.14 due to following:

 1. The Linuxthreads.old based userspace at the time caused many more
    exceptions in delay slot than the current NPTL based one.
    Infact with current userspace the error doesn't happen at all.

 2. Return from interrupt (delay slot or otherwise) doesn't get exercised much
    after commit 4de0e52867 ("Really Re-enable interrupts to avoid deadlocks")
    since IRQ_ACTIVE.active being clear means most returns are as if from pure
    kernel (even for active interrupts)

Infact the issue only happened in an experimental branch where I was tinkering with
reverted 4de0e52867

Cc: stable@kernel.org # v4.2+
Fixes: 4255b07f2c ("ARCv2: STAR 9000793984: Handle return from intr to Delay Slot")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-01-22 17:25:03 +05:30
Linus Torvalds 0f0836b7eb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching updates from Jiri Kosina:

 - RO/NX attribute fixes for patch module relocations from Josh
   Poimboeuf.  As part of this effort, module.c has been cleaned up as
   well and livepatching is piggy-backing on this cleanup.  Rusty is OK
   with this whole lot going through livepatching tree.

 - symbol disambiguation support from Chris J Arges.  That series is
   also

        Reviewed-by: Miroslav Benes <mbenes@suse.cz>

   but this came in only after I've alredy pushed out.  Didn't want to
   rebase because of that, hence I am mentioning it here.

 - symbol lookup fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Cleanup module page permission changes
  module: keep percpu symbols in module's symtab
  module: clean up RO/NX handling.
  module: use a structure to encapsulate layout.
  gcov: use within_module() helper.
  module: Use the same logic for setting and unsetting RO/NX
  livepatch: function,sympos scheme in livepatch sysfs directory
  livepatch: add sympos as disambiguator field to klp_reloc
  livepatch: add old_sympos as disambiguator field to klp_func
2016-01-14 16:38:02 -08:00
Vineet Gupta 6b538db7c6 ARC: dw2 unwind: Catch Dwarf SNAFUs early
Instead of seeing empty stack traces, let kernel fail early so dwarf
issues can be fixed sooner

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 14:01:49 +05:30
Vineet Gupta 6d0d506012 ARC: dw2 unwind: Don't bail for CIE.version != 1
The rudimentary CIE.version == 3 handling is already present in code
(for return address register specification)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-21 14:01:25 +05:30
Vineet Gupta 2d64affc92 Revert "ARC: dw2 unwind: Ignore CIE version !=1 gracefully instead of bailing"
Blingly ignoring CIE.version != 1 was a bad idea.
It still leaves "desirability" when running perf with callgraphing where libgcc
symbols might show in hotspot.

More importantly, basic CIE.version == 3 support already exists in code:

|
|   retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end);
|

Next commit with simply add continue-not-bail for CIE.version != 1

This reverts commit 323f41f9e7.
2015-12-21 13:29:44 +05:30
Vineet Gupta 575a9d4e2c ARC: smp: Rename platform hook @init_cpu_smp -> @init_per_cpu
Makes it similar to smp_ops which also has callback with same name

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 12:56:56 +05:30
Noam Camus b474a02382 ARC: rename smp operation init_irq_cpu() to init_per_cpu()
This will better reflect its description i.e. "any needed setup..."
and not just do an "IPI request".

Signed-off-by: Noam Camus <noamc@ezchip.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 12:56:43 +05:30
Vineet Gupta 323f41f9e7 ARC: dw2 unwind: Ignore CIE version !=1 gracefully instead of bailing
ARC dwarf unwinder only supports CIE version == 1
The boot time dwarf sanitizer (part of binary lookup table constructor)
would simply bail if it saw CIE version == 3, rendering unwinder with a
NULL lookup table.

It seems libgcc linked with kernel does have such entries.

With fallback linear search removed, and a NULL binary lookup table,
unwinder fails to generate any stack trace.

So allow graceful ignoring of unsupported CIE entries.

This problem was initially seen in Alexey's setup (and not mine) as he
was using buildroot built toolchain (libgcc) which doesn't get built with
CFLAGS_FOR_TARGET="-gdwarf-2 which is my default

Fixes STAR 9000985048: "kernel unwinder broken with stock tools"

Fixes: 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Reported-by Alexey Brodkin <abrodkin@synopsys.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 11:10:23 +05:30
Vineet Gupta bc79c9a721 ARC: dw2 unwind: Reinstante unwinding out of modules
The fix which removed linear searching of dwarf (because binary lookup
data always exists) missed out on the fact that modules don't get the
binary lookup tables info. This caused unwinding out of modules to stop
working.

So add binary lookup header setup (equivalent of eh_frame_hdr setup) to
modules as well.

While at it, confine the header setup to within unwinder code,
reducing one API exposed out of unwinder code.

Fixes: 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-17 11:10:23 +05:30
Vineet Gupta c512c6ba7a ARC: intc: Document arc_request_percpu_irq() better
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:04:12 +05:30
Vineet Gupta c6317bc7c5 ARCv2: perf: Ensure perf intr gets enabled on all cores
This was the second perf intr issue

perf sampling on multicore requires intr to be enabled on all cores.
ARC perf probe code used helper arc_request_percpu_irq() which calls
 - request_percpu_irq() on core0
 - enable_percpu_irq() on all all cores (including core0)

genirq requires that request be made ahead of enable call.
However if perf probe happened on non core0 (observed on a 3.18 kernel),
enable would get called ahead of request, failing obviously and
rendering perf intr disabled on all such cores

[   11.120000] 1 ARC perf       : 8 counters (48 bits), 113 conditions, [overflow IRQ support]
[   11.130000] 1 -----> enable_percpu_irq() IRQ 20 failed
[   11.140000] 3 -----> enable_percpu_irq() IRQ 20 failed
[   11.140000] 2 -----> enable_percpu_irq() IRQ 20 failed
[   11.140000] 0 =====> request_percpu_irq() IRQ 20
[   11.140000] 0 -----> enable_percpu_irq() IRQ 20

Fix this fragility, by calling request_percpu_irq() on whatever core
calls probe (there is no requirement on which core calls this anyways)
and then calling enable on each cores.

Interestingly this started as invesigation of STAR 9000838902:
"sporadically IRQs enabled on perf prob"

which was about occassional boot spew as request_percpu_irq got called
non-locally (from an IPI), and re-enabled interrupts in following path
proc_mkdir ->  spin_unlock_irq()

which the irq work code didn't like.

| ARC perf     : 8 counters (48 bits), 113 conditions, [overflow IRQ support]
|
| BUG: failure at ../kernel/irq_work.c:135/irq_work_run_list()!
| CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.10-01127-g285efb8e66d1 #2
|
| Stack Trace:
|  arc_unwind_core.constprop.1+0x94/0x104
|  dump_stack+0x62/0x98
|  irq_work_run_list+0xb0/0xb4
|  irq_work_run+0x22/0x3c
|  do_IPI+0x74/0x9c
|  handle_irq_event_percpu+0x34/0x164
|  handle_percpu_irq+0x58/0x78
|  generic_handle_irq+0x1e/0x2c
|  arch_do_IRQ+0x3c/0x60
|  ret_from_exception+0x0/0x8

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: <stable@vger.kernel.org> #4.2+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:03:59 +05:30
Vineet Gupta 5bf704c204 ARC: intc: No need to clear IRQ_NOAUTOEN
arc_request_percpu_irq() is called by all cores to request/enable percpu
irq. It has some "prep" calls needed by genirq:
 - setup percpu devid
 - disable IRQ_NOAUTOEN

However given that enable_percpu_irq() is called enayways, latter can be
avoided.

We are now left with irq_set_percpu_devid() quirk and that too for
ARCompact builds only, since previous patch updated ARCv2 intc to do this
in the "right" place, i.e. irq map function.

By next release, this will ultimately be fixed for ARCompact as well.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:03:59 +05:30
Vineet Gupta 8eb0984bf4 ARCv2: intc: Fix random perf irq disabling in SMP setup
As part of fixing another perf issue, observed that after a perf run,
the interrupt got disabled on one/more cores.

Turns out that despite requesting perf irq as percpu, the flow handler
registered was not handle_percpu_irq()

Given that on ARCv2 cores, IRQs < 24 are always private to cpu, we
register the right handler at the very onset.

Before Fix

| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0      0      0       0  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0    522      8    51916  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0    522      8   104368  ARCv2 core Intc  20 ARC perf counters

After Fix

| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:    0      0      0       0  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20:  64198  62012  62697  67803  ARCv2 core Intc  20 ARC perf counters
|
| [ARCLinux]# perf record -c 20000 /sbin/hackbench
| Running with 10*40 (== 400) tasks.
|
| [ARCLinux]# cat /proc/interrupts | grep perf
|  20: 126014 122792 123301 133654  ARCv2 core Intc  20 ARC perf counters

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: stable@vger.kernel.org #4.2+
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-12-12 16:03:41 +05:30
Rusty Russell 7523e4dc50 module: use a structure to encapsulate layout.
Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.

It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).

Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-12-04 22:46:25 +01:00
Vineet Gupta 2e22502c08 ARC: dw2 unwind: Remove falllback linear search thru FDE entries
Fixes STAR 9000953410: "perf callgraph profiling causing RCU stalls"

| perf record -g -c 15000 -e cycles /sbin/hackbench
|
| INFO: rcu_preempt self-detected stall on CPU
| 1: (1 GPs behind) idle=609/140000000000002/0 softirq=2914/2915 fqs=603
| Task dump for CPU 1:

in-kernel dwarf unwinder has a fast binary lookup and a fallback linear
search (which iterates thru each of ~11K entries) thus takes 2 orders of
magnitude longer (~3 million cycles vs. 2000). Routines written in hand
assembler lack dwarf info (as we don't support assembler CFI pseudo-ops
yet) fail the unwinder binary lookup, hit linear search, failing
nevertheless in the end.

However the linear search is pointless as binary lookup tables are created
from it in first place. It is impossible to have binary lookup fail while
succeed the linear search. It is pure waste of cycles thus removed by
this patch.

This manifested as RCU stalls / NMI watchdog splat when running
hackbench under perf with callgraph profiling. The triggering condition
was perf counter overflowing in routine lacking dwarf info (like memset)
leading to patheic 3 million cycle unwinder slow path and by the time it
returned new interrupts were already pending (Timer, IPI) and taken
rightaway. The original memset didn't make forward progress, system kept
accruing more interrupts and more unwinder delayes in a vicious feedback
loop, ultimately triggering the NMI diagnostic.

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-23 21:36:49 +05:30
Vineet Gupta e81b75f7b2 ARC: remove SYNC from __switch_to()
SYNC in __switch_to() is a historic relic and not needed at all.

 - In UP context it is obviously useless, why would we want to stall
   the core for all updates to stack memory of t0 to complete before
   loading kernel mode callee registers from t1 stack's memory.

 - In SMP, there could be potential race in which outgoing task could
   be concurrently picked for running on a different core, thus writes
   to stack here need to be visible before the reads from stack on
   other core. Peter confirmed that generic schedular already has needed
   barriers (by way of rq lock) so there is no need for additional arch
   barrier.

This came up when Noam was trying to replace this SYNC with EZChip
specific hardware thread scheduling instruction for their platform
support.

Link: http://lkml.kernel.org/r/20151102092654.GM17308@twins.programming.kicks-ass.net
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-17 22:05:30 +05:30
Vineet Gupta 512b5b89b9 ARC: Abstract out ISA specific SLEEP args
No semantical changes, prepares for ARCv2 specific change in next commit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-16 14:17:02 +05:30
Vineet Gupta 541366da6a ARC: [arcompact] Handle bus error from userspace as Interrupt not exception
Bus errors from userspace on ARCompact based cores are handled by core
as a high priority L2 interrupt but current code treated it as interrupt
Handling an interrupt like exception is certainly not going to go unnoticed.
(and it worked so far as we never saw a Bus error from userspace until
IPPK guys tested a DDR controller with ECC error detection etc hence
needed to explicitly trigger/handle such errors)

 - So move mem_service exception handler from common code into ARCv2 code.
 - In ARCompact code, define  mem_service as L2 interrupt handler which
   just drops down to pure kernel mode and goes of to enqueue SIGBUS

Reported-by: Nelson Pereira <npereira@synopsys.com>
Tested-by: Ana Martins <amartins@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-11-14 13:12:20 +05:30
Vineet Gupta 483bcc99c0 ARC: boot: Non Master cpus only need to call EARLY_CPU_SETUP once
With prev fixes, all cores now start via common entry point @stext which
already calls EARLY_CPU_SETUP for all cores - so no need to invoke it
again

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:42 +05:30
Vineet Gupta aa0efcde45 ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp()
MCIP now registers it's own per cpu setup routine (for IPI IRQ request)
using smp_ops.init_irq_cpu().

So no need for platforms to do that. This now completely decouples
platforms from MCIP.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:41 +05:30
Vineet Gupta 286130ebf1 ARC: smp: Introduce smp hook @init_irq_cpu called for all cores
Note this is not part of platform owned static machine_desc,
but more of device owned plat_smp_ops (rather misnamed) which a IPI
provider or some such typically defines.

This will help us seperate out the IPI registration from platform
specific init_cpu_smp() into device specific init_irq_cpu()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:41 +05:30
Vineet Gupta 8721a7f5a6 ARC: smp: Rename platform hook @init_smp -> @init_cpu_smp
This conveys better that it is called for each cpu

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta 26b8f99623 ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_early_smp()
MCIP now registers it's own probe callback with smp_ops.init_early_smp()
which is called by ARC common code, so no need for platforms to do that.

This decouples the platforms and MCIP and helps confine MCIP details
to it's own file.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta e55af4da02 ARC: smp: Introduce smp hook @init_early_smp for Master core
This adds a platform agnostic early SMP init hook which is called on
Master core before calling setup_processor()

  setup_arch()
     smp_init_cpus()
         smp_ops.init_early_smp()
     ...
     setup_processor()

How this helps:
 - Used for one time init of certain SMP centric IP blocks, before
   calling setup_processor() which probes various bits of core,
   possibly including this block

 - Currently platforms need to call this IP block init from their
   init routines, which doesn't make sense as this is specific to ARC
   core and not platform and otherwise requires copy/paste in all
   (and hence a possible point of failure)

e.g. MCIP init is called from 2 platforms currently (axs10x and sim)
which will go away once we have this.

This change only adds the hooks but they are empty for now. Next commit
will populate them and remove the explicit init calls from platforms.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:40 +05:30
Vineet Gupta 4c82f28617 ARC: remove @init_time, @init_irq platform callbacks
These are not in use for ARC platforms. Moreover DT mechanims exist to
probe them w/o explicit platform calls.

 - clocksource drivers can use CLOCKSOURCE_OF_DECLARE()
 - intc IRQCHIP_DECLARE() calls + cascading inside DT allows external
   intc to be probed automatically

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:39 +05:30
Vineet Gupta e0868e6f67 ARC: smp: irqchip: handle IPI as percpu irq like timer
The reason this was not done so far was lack of genuine IPI_IRQ for
ARC700, as we don't have a SMP version of core yet (which might change
soon thx to EZChip). Nevertheles to increase the build coverage, we
need to allow CONFIG_SMP for ARC700 and still be able to run it on a
UP platform (nsim or AXS101) with a UP Device Tree (SMP-on-UP)

The build itself requires some define for IPI_IRQ and even a dummy
value is fine since that code won't run anyways.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:13:39 +05:30
Vineet Gupta 3971cdc202 ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modes
For Run-on-reset, non masters need to spin wait. For Halt-on-reset they
can jump to entry point directly.

Also while at it, made reset vector handler as "the" entry point for
kernel including host debugger based boot (which uses the ELF header
entry point)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-28 16:08:17 +05:30
Vineet Gupta f33e9c434b ARC: smp: Move default boot kick/wait code out of MCIP into common code
For non halt-on-reset case, all cores start of simultaneously in @stext.
Master core0 proceeds with kernel boot, while other spin-wait on
@wake_flag being set by master once it is ready. So NO hardware assist
is needed for master to "kick" the others.

This patch moves this soft implementation out of mcip.c (as there is no
hardware assist) into common smp.c

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:27 +05:30
Vineet Gupta 964cf28f9d ARC: boot log: move helper macros to header for reuse
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:25 +05:30
Vineet Gupta 9fabcc636b ARC: [arcompact] entry.S: Elide extra check/branch in exception ret path
This is done by improving the laddering logic !

Before:

   if Exception
      goto excep_or_pure_k_ret

   if !Interrupt(L2)
      goto l1_chk
   else
      INTERRUPT_EPILOGUE 2

 l1_chk:
   if !Interrupt(L1)  (i.e. pure kernel mode)
      goto excep_or_pure_k_ret
   else
      INTERRUPT_EPILOGUE 1

 excep_or_pure_k_ret:
   EXCEPTION_EPILOGUE

Now:

   if !Interrupt(L1 or L2) (i.e. exception or pure kernel mode)
      goto excep_or_pure_k_ret

  ; guaranteed to be an interrupt
   if !Interrupt(L2)
      goto l1_ret
   else
      INTERRUPT_EPILOGUE 2

 ; by virtue of above, no need to chk for L1 active
 l1_ret:
    INTERRUPT_EPILOGUE 1

 excep_or_pure_k_ret:
    EXCEPTION_EPILOGUE

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:23 +05:30
Vineet Gupta 5f88808745 ARC: [arcompact] entry.S: Document preemption games for L2 intr
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:23 +05:30
Vineet Gupta 9dbd3d9bfd ARC: [arcompact] don't check for hard isr calling local_irq_enable()
Historically this was done by ARC IDE driver, which is long gone.
IRQ core is pretty robust now and already checks if IRQs are enabled
in hard ISRs. Thus no point in checking this in arch code, for every
call of irq enabled.

Further if some driver does do that - let it bring down the system so we
notice/fix this sooner than covering up for sucker

This makes local_irq_enable() - for L1 only case atleast simple enough
so we can inline it.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17 17:48:22 +05:30
Thomas Gleixner bd0b9ac405 genirq: Remove irq argument from irq flow handlers
Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-09-16 15:47:51 +02:00
Linus Torvalds 17e6b00ac4 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "This updated pull request does not contain the last few GIC related
  patches which were reported to cause a regression.  There is a fix
  available, but I let it breed for a couple of days first.

  The irq departement provides:

   - new infrastructure to support non PCI based MSI interrupts
   - a couple of new irq chip drivers
   - the usual pile of fixlets and updates to irq chip drivers
   - preparatory changes for removal of the irq argument from interrupt
     flow handlers
   - preparatory changes to remove IRQF_VALID"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources
  irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2
  irqchip: Add documentation for the bcm2836 interrupt controller
  irqchip/bcm2835: Add support for being used as a second level controller
  irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ
  PCI: xilinx: Fix typo in function name
  irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instance
  irqchip/gic: Only allow the primary GIC to set the CPU map
  PCI/MSI: pci-xgene-msi: Consolidate chained IRQ handler install/remove
  unicore32/irq: Prepare puv3_gpio_handler for irq argument removal
  tile/pci_gx: Prepare trio_handle_level_irq for irq argument removal
  m68k/irq: Prepare irq handlers for irq argument removal
  C6X/megamode-pic: Prepare megamod_irq_cascade for irq argument removal
  blackfin: Prepare irq handlers for irq argument removal
  arc/irq: Prepare idu_cascade_isr for irq argument removal
  sparc/irq: Use access helper irq_data_get_affinity_mask()
  sparc/irq: Use helper irq_data_get_irq_handler_data()
  parisc/irq: Use access helper irq_data_get_affinity_mask()
  mn10300/irq: Use access helper irq_data_get_affinity_mask()
  irqchip/i8259: Prepare i8259_irq_dispatch for irq argument removal
  ...
2015-09-01 14:33:35 -07:00
Vineet Gupta 3d5926599a ARCv2: entry: Fix reserved handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 16:25:37 +05:30
Vineet Gupta 9b28829d6d ARCv2: perf: Finally introduce HS perf unit
With all features in place, the ARC HS pct block can now be effectively
allowed to be probed/used

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:59:07 +05:30
Alexey Brodkin e525c37f84 ARCv2: perf: SMP support
* split off pmu info into singleton and per-cpu bits
* setup PMU on all cores

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:58:42 +05:30
Alexey Brodkin e6b1d126bb ARCv2: perf: implement exclusion of event counting in user or kernel mode
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:58:14 +05:30
Alexey Brodkin 36481cf7fb ARCv2: perf: Support sampling events using overflow interrupts
In times of ARC 700 performance counters didn't have support of
interrupt an so for ARC we only had support of non-sampling events.

Put simply only "perf stat" was functional.

Now with ARC HS we have support of interrupts in performance counters
which this change introduces support of.

ARC performance counters act in the following way in regard of
interrupts generation.
 [1] A counter counts starting from value set in PCT_COUNT register pair
 [2] Once counter reaches value set in PCT_INT_CNT interrupt is raised

Basic setup look like this:
 [1] PCT_COUNT = 0;
 [2] PCT_INT_CNT = __limit_value__;
 [3] Enable interrupts for that counter and let it run
 [4] Let counter reach its limit
 [5] Handle interrupt when it happens

Note that PCT HW block is build in CPU core and so ints interrupt
line (which is basically OR of all counters IRQs) is wired directly to
top-level IRQC. That means do de-assert PCT interrupt it's required to
reset IRQs from all counters that have reached their limit values.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:57:43 +05:30
Alexey Brodkin 1fe8bfa5ff ARCv2: perf: implement "event_set_period"
This generalization prepares for support of overflow interrupts.

Hardware event counters on ARC work that way:
Each counter counts from programmed start value (set in
ARC_REG_PCT_COUNT) to a limit value (set in ARC_REG_PCT_INT_CNT) and
once limit value is reached this timer generates an interrupt.

Even though this hardware implementation allows for more flexibility,
in Linux kernel we decided to mimic behavior of other architectures
this way:

 [1] Set limit value as half of counter's max value (to allow counter to
     run after reaching it limit, see below for more explanation):
 ---------->8-----------
 arc_pmu->max_period = (1ULL << counter_size) / 2 - 1ULL;
 ---------->8-----------

 [2] Set start value as "arc_pmu->max_period - sample_period" and then
count up to the limit

Our event counters don't stop on reaching max value (the one we set in
ARC_REG_PCT_INT_CNT) but continue to count until kernel explicitly
stops each of them.

And setting a limit as half of counter capacity is done to allow
capturing of additional events in between moment when interrupt was
triggered until we're actually processing PMU interrupts. That way
we're trying to be more precise.

For example if we count CPU cycles we keep track of cycles while
running through generic IRQ handling code:

 [1] We set counter period as say 100_000 events of type "crun"
 [2] Counter reaches that limit and raises its interrupt
 [3] Once we get in PMU IRQ handler we read current counter value from
ARC_REG_PCT_SNAP ans see there something like 105_000.

If counters stop on reaching a limit value then we would miss
additional 5000 cycles.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:57:29 +05:30
Vineet Gupta fb7c572551 ARC: perf: cap the number of counters to hardware max of 32
The number of counters in PCT can never be more than 32 (while
countable conditions could be 100+) for both ARCompact and ARCv2

And while at it update copyright dates.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-27 14:57:03 +05:30
Vineet Gupta 090749502f ARC: add/fix some comments in code - no functional change
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 19:05:49 +05:30
Yuriy Kolerov 6de6066c0d ARC: change some branchs to jumps to resolve linkage errors
When kernel's binary becomes large enough (32M and more) errors
may occur during the final linkage stage. It happens because
the build system uses short relocations for ARC  by default.
This problem may be easily resolved by passing -mlong-calls
option to GCC to use long absolute jumps (j) instead of short
relative branchs (b).

But there are fragments of pure assembler code exist which use
branchs in inappropriate places and cause a linkage error because
of relocations overflow.

First of these fragments is .fixup insertion in futex.h and
unaligned.c. It inserts a code in the separate section (.fixup)
with branch instruction. It leads to the linkage error when
kernel becomes large.

Second of these fragments is calling scheduler's functions
(common kernel code) from entry.S of ARC's code. When kernel's
binary becomes large it may lead to the linkage error because
scheduler may occur far enough from ARC's code in the final
binary.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-20 18:53:15 +05:30
Vineet Gupta e78fdfef84 ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff
This is to workaround the llock/scond livelock

HS38x4 could get into a LLOCK/SCOND livelock in case of multiple overlapping
coherency transactions in the SCU. The exclusive line state keeps rotating
among contenting cores leading to a never ending cycle. So break the cycle
by deferring the retry of failed exclusive access (SCOND). The actual delay
needed is function of number of contending cores as well as the unrelated
coherency traffic from other cores. To keep the code simple, start off with
small delay of 1 which would suffice most cases and in case of contention
double the delay. Eventually the delay is sufficient such that the coherency
pipeline is drained, thus a subsequent exclusive access would succeed.

Link: http://lkml.kernel.org/r/1438612568-28265-1-git-send-email-vgupta@synopsys.com
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-04 09:26:34 +05:30
Vineet Gupta e13c42ecbe ARCv2: Fix the peripheral address space detection
With HS 2.1 release, the peripheral space register no longer contains
the uncached space specifics, causing the kernel to panic early on.
So read the newer NON VOLATILE AUX register to get that info.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-08-03 19:34:07 +05:30
Thomas Gleixner badae6bc94 arc/irq: Prepare idu_cascade_isr for irq argument removal
The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.

Search and update was done with coccinelle and the invaluable help of
Julia Lawall.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Vineet Gupta <vgupta@synopsys.com>
2015-07-31 22:20:05 +02:00
Viresh Kumar aeec6cdad6 ARC/time: Migrate to new 'set-state' interface
Migrate arc driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-20 13:30:31 +03:00
Vineet Gupta 624b71ee20 ARCv2: support HS38 releases
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-13 13:33:23 +05:30
Vineet Gupta b631788ab4 ARC: slightly refactor macros for boot logging
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:33 +05:30
Joël Porquet 70d93d8941 arc:irqchip: prepare for drivers/irqchip/irqchip.h removal
The IRQCHIP_DECLARE macro migrated to 'include/linux/irqchip.h'.

See commit 91e20b5040
("irqchip: Move IRQCHIP_DECLARE macro to include/linux/irqchip.h").

This patch removes the inclusions of private header 'drivers/irqchip/irqchip.h'
and if necessary replaces them with inclusions of 'include/linux/irqchip.h'.

Signed-off-by: Joel Porquet <joel@porquet.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-09 17:36:32 +05:30
Vineet Gupta 6b12ec177c ARCv2: intc: IDU: Fix potential race in installing a chained IRQ handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:06 +05:30
Vineet Gupta 83ce3e6fcc ARCv2: intc: IDU: support irq affinity
With this nsim standlone / OSCI have working irq affinity - AXS103 still
needs some work as IDU is not visible in intc hierarchy yet !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:02 +05:30
Vineet Gupta bccea41ec0 ARC: fix unused var wanring
Fixes: 9bf39ab2ad ("vfs: add file_path() helper")
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-07-06 11:09:01 +05:30
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Vineet Gupta 40b8ad8f76 ARC: Fix build failures for ARCompact in linux-next after ARCv2 support
Reported-by: Guenter Roeck <private@roeck-us.net>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-28 20:30:13 +05:30
Ruud Derwig 2924cd18c4 ARCv2: [vdk] dts files and defconfig for HS38 VDK
- CONFIG_ARC_UBOOT_SUPPORT to handle arguments passed in r0, r1, r2
 - CONFIG_DEVTMPFS_MOUNT for mouting rootfs since it uses external cpio
   for rootfs

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Ruud Derwig <rderwig@synopsys.com>
[vgupta: folded the Main baord DT files for smp/up into one]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:21 +05:30
Vineet Gupta 5fa2daaa8d ARCv2: [axs103] Support ARC SDP FPGA platform for HS38x cores
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-25 06:00:20 +05:30
Miklos Szeredi 9bf39ab2ad vfs: add file_path() helper
Turn
	d_path(&file->f_path, ...);
into
	file_path(file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:00:05 -04:00
Vineet Gupta eaf0ecc33f ARCv2: SMP: intc: IDU 2nd level intc for dynamic IRQ distribution
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta 72d7288061 ARCv2: SMP: clocksource: Enable Global Real Time counter
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta aa6083ed50 ARCv2: SMP: ARConnect debug/robustness
- Handle possible interrupt coalescing from MCIP
- chk if prev IPI ack before sending new

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:57 +05:30
Vineet Gupta 82fea5a1bb ARCv2: SMP: Support ARConnect (MCIP) for Inter-Core-Interrupts et al
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta 173eaafaed ARC: make plat_smp_ops weak to allow over-rides
This allows platforms to provide their own cpu wakeup routines
as well as IPI send / clear backends, while allowing a SMP kernel w/o
any such backend to build/boot

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta aa93e8ef98 ARCv2: clocksource: Introduce 64bit local RTC counter
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:56 +05:30
Vineet Gupta 0d7b8855a0 ARCv2: STAR 9000808988: signals involving Delay Slot
Reported by Anton as LTP:munmap01 failing with Illegal Instruction
Exception.

   --------------------->8--------------------------------------
   mmap2(NULL, 24576, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x200d2000
   munmap(0x200d2000, 24576)               = 0
   --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x200d2000}
   ---
   potentially unexpected fatal signal 4.
   Path: /munmap01
   CPU: 0 PID: 61 Comm: munmap01 Not tainted 3.13.0-g5d5c46d9a556 #8
   task: 9f1a8000 ti: 9f154000 task.ti: 9f154000

   [ECR   ]: 0x00020100 => Illegal Insn
   [EFA   ]: 0x0001354c
   [BLINK ]: 0x200515d4
   [ERET  ]: 0x1354c
       @off 0x1354c in [/munmap01]
       VMA: 0x00010000 to 0x00018000
   [STAT32]: 0x800802c0
   ...
   --------------------->8--------------------------------------

The issue was
1. munmap01 accessed unmapped memory (on purpose) with signal handler
   installed for SIGSEGV

2. The faulting instruction happened to be in Delay Slot
   00011864 <main>:
      11908:	bl.d       13284 <tst_resm>
      1190c:	stb        r16,[r2]

3. kernel sets up the reg file for signal handler and correctly clears
   the DE bit in pt_regs->status32 placeholder

4. However RESTORE_CALLEE_SAVED_USER macro is not adjusted for ARCv2,
   and it over-writes the above with orig/stale value of status32

5. After RTIE, userspace signal handler executes a non branch
   instruction with DE bit set, triggering Illegal Instruction Exception.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 4255b07f2c ARCv2: STAR 9000793984: Handle return from intr to Delay Slot
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 1f6ccfff63 ARCv2: Support for ARCv2 ISA and HS38x cores
The notable features are:
    - SMP configurations of upto 4 cores with coherency
    - Optional L2 Cache and IO-Coherency
    - Revised Interrupt Architecture (multiple priorites, reg banks,
        auto stack switch, auto regfile save/restore)
    - MMUv4 (PIPT dcache, Huge Pages)
    - Instructions for
	* 64bit load/store: LDD, STD
	* Hardware assisted divide/remainder: DIV, REM
	* Function prologue/epilogue: ENTER_S, LEAVE_S
	* IRQ enable/disable: CLRI, SETI
	* pop count: FFS, FLS
	* SETcc, BMSKN, XBFU...

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 820970a5aa ARCv2: [intc] HS38 core interrupt controller
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:55 +05:30
Vineet Gupta 10d11e580c ARC: uncached base is hard constant for ARC, don't save it
ioremap already uses the hard define, just make sure BCR value matches
that

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-22 14:06:54 +05:30
Vineet Gupta 5793e273a1 ARC: intc: split into ARCompact ISA specific, common bits
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:40 +05:30
Vineet Gupta 6ffb9c8c5f ARC: Make way for pt_regs != user_regs_struct
These have been register compatible so far. However ARCv2 mandates
different pt_regs layout (due to h/w auto save). To keep pt_regs same
for both, we start by removing the assumption - used mainly for block
copies between the 2 structs in signal handling and ptrace

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:40 +05:30
Vineet Gupta c80417b612 ARC: entry.S: use single EXCEPTION_PROLOGUE
Returning from pure kernel mode and exception mode use the same code
anyways. Remove one the duplicate blocks

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:39 +05:30
Vineet Gupta 62fb64034d ARC: entry.S: micro-optimize Trap handler
Elide the need to re-read ECR in Trap handler by ensuring that
EXCEPTION_PROLOGUE does that at the very end just before returning
to Trap handler

ARCv2 EXCEPTION_PROLOGUE already did that, so same for ARcompact and the
common trap handler adjusted to use cached ECR

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:39 +05:30
Vineet Gupta c7e6d79204 ARC: entry.S: move some code around for cache locality in return path
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:38 +05:30
Vineet Gupta 6d1a20b1d2 ARC: entry.S: split into ARCompact ISA specific, common bits
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:38 +05:30
Vineet Gupta c10d6969b0 ARC: entry.S: Ensure that restore_regs is local to compilation unit
This fixes the possible link/relo errors, since restore_regs will be
provided by ISA code, but called from ARC common code.
The .L prefix reassures binutils that it will be in same compilation
unit.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:37 +05:30
Vineet Gupta 4bf4564b27 ARC: entry.S: comments cleanup
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:37 +05:30
Vineet Gupta a8717d2808 ARC: entry.S: Trap handler to use r10 for syscall vs. brkpt decision
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:36 +05:30
Vineet Gupta 9b8c7d1e71 ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:36 +05:30
Vineet Gupta a615b47dbf ARC: entry.S: confine EXCEPTION_* macros to one file
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:35 +05:30
Vineet Gupta f033737e77 ARC: entry.S: canonical'ize EXCEPTION_{PROLOGUE,EPILOGUE}
-EXCEPTION_EPILOGUE introduced
-EXCEPTION_PROLOGUE now also includes reg file saving

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:35 +05:30
Vineet Gupta 09f3b37e4e ARC: entry.S: Introduce INTERRUPT_{PROLOGUE,EPILOGUE}
-common'ize macros for level 1 and level 2 interrupts

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:34 +05:30
Vineet Gupta fbfa26ae3b ARC: entry.S: common'ize scrtach reg freeup in intr + exceptions
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:34 +05:30
Vineet Gupta 8d0d56ba24 ARC: [axs101] support early 8250 uart
Earlycon calculates UART clock as "BASE_BAUD * 16". In case of ARC
"BASE_BAUD" is calculated dynamically in runtime, basically it is an
alias to arc_early_base_baud(), which in turn just does
"arc_base_baud/16".

8250 UART on AXS/SDP board uses 33.3MHz clock source which is set in
"arc_base_baud" with this change.

Additional compatibility string "snps,arc-sdp" is introduced as well
because there're different flavours of AXS boards but they all share the
same motherboard and so it's possible to re-use the same code for
motherbord even if CPU daughterboard changes.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:30 +05:30
Vineet Gupta def32fad84 ARC: stack unwinder to bail if PC is not kernel mode
Currently, it doesn't invoke the callback but continues to unwind

Also while at it - simplify the code a bit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:29 +05:30
Tobias Klauser 082ae1e157 ARC: perf: Remove unnecessary local variable
Directly return the result of perf_pmu_register() in
arc_pmu_device_probe() instead of assigning and returning variable ret.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:28 +05:30
Max Filippov 7002f77541 arc: fix use of uninitialized arc_pmu
static arc_pmu in the arch/arc/kernel/perf_event.c is not initialized as
it's shadowed by a local variable of the same name in the
arc_pmu_device_probe.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Fixes: 03c94fcf95 "ARC: perf: make @arc_pmu static global"
CC: <stable@vger.kernel.org>	# 4.1
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:28 +05:30
Vineet Gupta b27f739171 ARC: fix section mismatch with allyesconfig
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:27 +05:30
Vineet Gupta 036b2c5664 ARC: explicit'ify uboot support
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:27 +05:30
Vineet Gupta 5b9bd17840 ARC: clocksource cleanups
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:25 +05:30
Vineet Gupta 565a9b497c ARC: RIP broken 64bit RTSC
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-06-19 18:09:24 +05:30
Linus Torvalds c76397e930 ARC changes for 4.1-rc1:
- perf fixes/improvements
 - miscll cleanups
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Merge tag 'arc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC updates from Vineet Gupta:

 - perf fixes/improvements

 - misc cleanups

* tag 'arc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: perf: don't add code for impossible case
  ARC: perf: Rename DT binding to not confuse with power mgmt
  ARC: perf: add user space attribution in callchains
  ARC: perf: Add kernel callchain support
  ARC: perf: support cache hit/miss ratio
  ARC: perf: Add some comments/debug stuff
  ARC: perf: make @arc_pmu static global
  ARC: mem init spring cleaning - No functional changes
  ARC: Fix RTT boot printing
  ARC: fold __builtin_constant_p() into test_bit()
  ARC: rename unhandled exception handler
  ARC: cosmetic: Remove unused ECR bitfield masks
  ARC: Fix WRITE_BCR
  ARC: [nsimosci] Update defconfig
  arc: copy_thread(): rename 'arg' argument to 'kthread_arg'
2015-04-24 07:55:54 -07:00
Vineet Gupta d8f6ad85cb ARC: perf: don't add code for impossible case
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20 18:27:55 +05:30
Vineet Gupta 30fdd373f2 ARC: perf: Rename DT binding to not confuse with power mgmt
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20 18:27:36 +05:30
Vineet Gupta 22f6b89912 ARC: perf: add user space attribution in callchains
The actual user space unwinding is more involved, so simply capture the
user space PC

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20 18:27:35 +05:30
Vineet Gupta 389e3160b9 ARC: perf: Add kernel callchain support
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20 18:27:35 +05:30
Vineet Gupta bde80c237e ARC: perf: Add some comments/debug stuff
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20 18:27:30 +05:30
Vineet Gupta 03c94fcf95 ARC: perf: make @arc_pmu static global
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-20 17:21:17 +05:30
Davidlohr Bueso be2a7fce39 arc: do not export symbols in troubleshoot.c
print_task_path_n_nm() is local to this file, its only user being
show_regs().  Mark the function static and avoid the EXPORT_SYMBOL.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Vineet Gupta <vgupta@synoipsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:09 -04:00
Linus Torvalds fa2e5c073a Merge branch 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc
Pull exec domain removal from Richard Weinberger:
 "This series removes execution domain support from Linux.

  The idea behind exec domains was to support different ABIs.  The
  feature was never complete nor stable.  Let's rip it out and make the
  kernel signal handling code less complicated"

* 'exec_domain_rip_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (27 commits)
  arm64: Removed unused variable
  sparc: Fix execution domain removal
  Remove rest of exec domains.
  arch: Remove exec_domain from remaining archs
  arc: Remove signal translation and exec_domain
  xtensa: Remove signal translation and exec_domain
  xtensa: Autogenerate offsets in struct thread_info
  x86: Remove signal translation and exec_domain
  unicore32: Remove signal translation and exec_domain
  um: Remove signal translation and exec_domain
  tile: Remove signal translation and exec_domain
  sparc: Remove signal translation and exec_domain
  sh: Remove signal translation and exec_domain
  s390: Remove signal translation and exec_domain
  mn10300: Remove signal translation and exec_domain
  microblaze: Remove signal translation and exec_domain
  m68k: Remove signal translation and exec_domain
  m32r: Remove signal translation and exec_domain
  m32r: Autogenerate offsets in struct thread_info
  frv: Remove signal translation and exec_domain
  ...
2015-04-15 13:53:55 -07:00
Linus Torvalds ca2ec32658 Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:
 "Part one:

   - struct filename-related cleanups

   - saner iov_iter_init() replacements (and switching the syscalls to
     use of those)

   - ntfs switch to ->write_iter() (Anton)

   - aio cleanups and splitting iocb into common and async parts
     (Christoph)

   - assorted fixes (me, bfields, Andrew Elble)

  There's a lot more, including the completion of switchover to
  ->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags
  race fixes, etc, but that goes after #for-davem merge.  David has
  pulled it, and once it's in I'll send the next vfs pull request"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits)
  sg_start_req(): use import_iovec()
  sg_start_req(): make sure that there's not too many elements in iovec
  blk_rq_map_user(): use import_single_range()
  sg_io(): use import_iovec()
  process_vm_access: switch to {compat_,}import_iovec()
  switch keyctl_instantiate_key_common() to iov_iter
  switch {compat_,}do_readv_writev() to {compat_,}import_iovec()
  aio_setup_vectored_rw(): switch to {compat_,}import_iovec()
  vmsplice_to_user(): switch to import_iovec()
  kill aio_setup_single_vector()
  aio: simplify arguments of aio_setup_..._rw()
  aio: lift iov_iter_init() into aio_setup_..._rw()
  lift iov_iter into {compat_,}do_readv_writev()
  NFS: fix BUG() crash in notify_change() with patch to chown_common()
  dcache: return -ESTALE not -EBUSY on distributed fs race
  NTFS: Version 2.1.32 - Update file write from aio_write to write_iter.
  VFS: Add iov_iter_fault_in_multipages_readable()
  drop bogus check in file_open_root()
  switch security_inode_getattr() to struct path *
  constify tomoyo_realpath_from_path()
  ...
2015-04-14 15:31:03 -07:00
Linus Torvalds d0bbe0dd35 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina:
 "Usual trivial tree updates.  Nothing outstanding -- mostly printk()
  and comment fixes and unused identifier removals"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  goldfish: goldfish_tty_probe() is not using 'i' any more
  powerpc: Fix comment in smu.h
  qla2xxx: Fix printks in ql_log message
  lib: correct link to the original source for div64_u64
  si2168, tda10071, m88ds3103: Fix firmware wording
  usb: storage: Fix printk in isd200_log_config()
  qla2xxx: Fix printk in qla25xx_setup_mode
  init/main: fix reset_device comment
  ipwireless: missing assignment
  goldfish: remove unreachable line of code
  coredump: Fix do_coredump() comment
  stacktrace.h: remove duplicate declaration task_struct
  smpboot.h: Remove unused function prototype
  treewide: Fix typo in printk messages
  treewide: Fix typo in printk messages
  mod_devicetable: fix comment for match_flags
2015-04-14 09:50:27 -07:00
Vineet Gupta a44ec8bd2a ARC: Fix RTT boot printing
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13 15:15:17 +05:30
Vineet Gupta 0dfb8ec70f ARC: rename unhandled exception handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-04-13 15:14:57 +05:30
Richard Weinberger e6de3ca91c arc: Remove signal translation and exec_domain
As execution domain support is gone we can remove
signal translation from the signal code and remove
exec_domain from thread_info.

Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-12 21:03:30 +02:00
Al Viro a555ad450f whack-a-mole: no need to set_fs(USER_DS) in {start,flush}_thread()
flush_old_exec() has already done that.  Back on 2011 a bunch of
instances like that had been kicked out, but that hadn't taken
care of then-out-of-tree architectures, obviously, and they served
as reinfection vector...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:24:31 -04:00
Alex Dowad 18e1d1b115 arc: copy_thread(): rename 'arg' argument to 'kthread_arg'
The 'arg' argument to copy_thread() is only ever used when forking a new
kernel thread. Hence, rename it to 'kthread_arg' for clarity.

Signed-off-by: Alex Dowad <alexinbeijing@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-31 11:20:51 +05:30
Vineet Gupta e4140819da ARC: signal handling robustify
A malicious signal handler / restorer can DOS the system by fudging the
user regs saved on stack, causing weird things such as sigreturn returning
to user mode PC but cpu state still being kernel mode....

Ensure that in sigreturn path status32 always has U bit; any other bogosity
(gargbage PC etc) will be taken care of by normal user mode exceptions mechanisms.

Reproducer signal handler:

    void handle_sig(int signo, siginfo_t *info, void *context)
    {
	ucontext_t *uc = context;
	struct user_regs_struct *regs = &(uc->uc_mcontext.regs);

	regs->scratch.status32 = 0;
    }

Before the fix, kernel would go off to weeds like below:

    --------->8-----------
    [ARCLinux]$ ./signal-test
    Path: /signal-test
    CPU: 0 PID: 61 Comm: signal-test Not tainted 4.0.0-rc5+ #65
    task: 8f177880 ti: 5ffe6000 task.ti: 8f15c000

    [ECR   ]: 0x00220200 => Invalid Write @ 0x00000010 by insn @ 0x00010698
    [EFA   ]: 0x00000010
    [BLINK ]: 0x2007c1ee
    [ERET  ]: 0x10698
    [STAT32]: 0x00000000 :                                   <--------
    BTA: 0x00010680	 SP: 0x5ffe7e48	 FP: 0x00000000
    LPS: 0x20003c6c	LPE: 0x20003c70	LPC: 0x00000000
    ...
    --------->8-----------

Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-26 11:19:36 +05:30
Vineet Gupta 6914e1e3f6 ARC: SA_SIGINFO ucontext regs off-by-one
The regfile provided to SA_SIGINFO signal handler as ucontext was off by
one due to pt_regs gutter cleanups in 2013.

Before handling signal, user pt_regs are copied onto user_regs_struct and copied
back later. Both structs are binary compatible. This was all fine until
commit 2fa919045b (ARC: pt_regs update #2) which removed the empty stack slot
at top of pt_regs (corresponding to first pad) and made the corresponding
fixup in struct user_regs_struct (the pad in there was moved out of
@scratch - not removed altogether as it is part of ptrace ABI)

 struct user_regs_struct {
+       long pad;
        struct {
-               long pad;
                long bta, lp_start, lp_end,....
        } scratch;
 ...
 }

This meant that now user_regs_struct was off by 1 reg w.r.t pt_regs and
signal code needs to user_regs_struct.scratch to reflect it as pt_regs,
which is what this commit does.

This problem was hidden for 2 years, because both save/restore, despite
using wrong location, were using the same location. Only an interim
inspection (reproducer below) exposed the issue.

     void handle_segv(int signo, siginfo_t *info, void *context)
     {
 	ucontext_t *uc = context;
	struct user_regs_struct *regs = &(uc->uc_mcontext.regs);

	printf("regs %x %x\n",               <=== prints 7 8 (vs. 8 9)
               regs->scratch.r8, regs->scratch.r9);
     }

     int main()
     {
	struct sigaction sa;

	sa.sa_sigaction = handle_segv;
	sa.sa_flags = SA_SIGINFO;
	sigemptyset(&sa.sa_mask);
	sigaction(SIGSEGV, &sa, NULL);

	asm volatile(
	"mov	r7, 7	\n"
	"mov	r8, 8	\n"
	"mov	r9, 9	\n"
	"mov	r10, 10	\n"
	:::"r7","r8","r9","r10");

	*((unsigned int*)0x10) = 0;
     }

Fixes: 2fa919045b "ARC: pt_regs update #2: Remove unused gutter at start of pt_regs"
CC: <stable@vger.kernel.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-03-26 09:38:00 +05:30
Masanari Iida d939be3add treewide: Fix typo in printk messages
This patch fix spelling typo in printk messages.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2015-03-06 23:05:39 +01:00
Vineet Gupta 3240dd57e5 ARC: Fix thread_saved_pc()
The old implementation assumed that SP at the time of __switch_to() is
right above pt_regs which is almost certainly not the case as there will
be some stack build up between entry into kernel and leading up to
__switch_to

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27 10:59:34 +05:30
Vineet Gupta 13648b0118 ARC: Fix KSTK_ESP()
/proc/<pid>/maps currently don't annotate stack vma with "[stack]"
This is because KSTK_ESP ie expected to return usermode SP of tsk while
currently it returns the kernel mode SP of a sleeping tsk.

While the fix is trivial, we also need to adjust the ARC kernel stack
unwinder to not use KSTK_SP and friends any more.

Cc: <stable@vger.kernel.org>
Reported-and-suggested-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27 10:48:23 +05:30
Vineet Gupta ceed97ab4f ARC: perf: Enable generic software events
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27 10:15:01 +05:30
Vineet Gupta 3a51d50f42 ARC: Make arc_unwind_core accessible externally
The arc unwinder can also be used for perf callchains.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-27 10:15:00 +05:30
Linus Torvalds a68fb48380 ARC updates for 3.20
Some fixes, nothing too exciting this time as well...
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Merge tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC updates from Vineet Gupta:
 "Some fixes, nothing too exciting this time as well..."

* tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
  ARC: Fix earlycon build breakage
  ARC: Dynamically determine BASE_BAUD from DeviceTree
  arc: Remove unused prepare_to_copy()
  ARC: use ACCESS_ONCE in cmpxchg loop
  ARC: add some more comments to ret_from_fork
  ARC: fix /proc/cpuinfo for offline cpus
2015-02-16 14:56:52 -08:00
Andy Lutomirski f56141e3e2 all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Peter Hurley 091f56be10 ARC: Fix earlycon build breakage
Commit ffb7fcd66f ("ARC: Dynamically determine BASE_BAUD from DeviceTree")
breaks arc:defconfig build:

       drivers/built-in.o: In function `of_setup_earlycon':
       (.init.text+0xb3e): undefined reference to `arc_early_base_baud'
       drivers/built-in.o: In function `setup_earlycon':
       (.init.text+0xcd0): undefined reference to `arc_early_base_baud'
       make: *** [vmlinux] Error 1

BASE_BAUD is only required for earlycon, which should depend on
CONFIG_SERIAL_EARLYCON.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-04 10:38:15 +05:30
Vineet Gupta ffb7fcd66f ARC: Dynamically determine BASE_BAUD from DeviceTree
8250 earlycon is broken on multi-platform ARC because the UART clk
value (BASE_BAUD) is fixed at build time.

Instead, determine the appropriate UART clk at runtime; parse the
devicetree early for platforms requiring alternate UART clk values
(currently only the TB10X platform).

Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02 17:08:37 +05:30
Vineet Gupta 7082a29c22 ARC: use ACCESS_ONCE in cmpxchg loop
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02 17:08:37 +05:30
Vineet Gupta 98edfab4c1 ARC: add some more comments to ret_from_fork
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02 17:08:37 +05:30
Vineet Gupta 4c86231c14 ARC: fix /proc/cpuinfo for offline cpus
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-02-02 17:08:37 +05:30
Vineet Gupta 9fb92eb116 ARC: R-M-W assist locks only needed for !LLSC
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-12-12 16:02:34 +05:30
Linus Torvalds 816fb4175c The "weak" attribute is commonly used for the default version of a
function, where an architecture can override it by providing a strong
 version.
 
 Some header file declarations included the "weak" attribute.  That's
 error-prone because it causes every implementation to be weak, with no
 strong version at all, and the linker chooses one based on link order.
 
 What we want is the "weak" attribute only on the *definition* of the
 default implementation.  These changes remove "weak" from the declarations,
 leaving it on the default definitions.
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Merge tag 'remove-weak-declarations' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull weak function declaration removal from Bjorn Helgaas:
 "The "weak" attribute is commonly used for the default version of a
  function, where an architecture can override it by providing a strong
  version.

  Some header file declarations included the "weak" attribute.  That's
  error-prone because it causes every implementation to be weak, with no
  strong version at all, and the linker chooses one based on link order.

  What we want is the "weak" attribute only on the *definition* of the
  default implementation.  These changes remove "weak" from the
  declarations, leaving it on the default definitions"

* tag 'remove-weak-declarations' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  uprobes: Remove "weak" from function declarations
  memory-hotplug: Remove "weak" from memory_block_size_bytes() declaration
  kgdb: Remove "weak" from kgdb_arch_pc() declaration
  ARC: kgdb: generic kgdb_arch_pc() suffices
  vmcore: Remove "weak" from function declarations
  clocksource: Remove "weak" from clocksource_default_clock() declaration
  x86, intel-mid: Remove "weak" from function declarations
  audit: Remove "weak" from audit_classify_compat_syscall() declaration
2014-10-23 15:04:27 -07:00
Vineet Gupta 4fbf81ca53 ARC: kgdb: generic kgdb_arch_pc() suffices
The ARC version of kgdb_arch_pc() is identical to the generic version in
kernel/debug/debug_core.c.  Drop the ARC version so we use the generic one.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-10-22 16:14:04 -06:00
Vineet Gupta 5637208253 ARC: boot: cpu feature print enhancements
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-10-13 14:46:22 +05:30
Vineet Gupta c4b9856b5e ARC: boot: consolidate cross-checking of h/w and s/w
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-10-13 14:46:22 +05:30
Vineet Gupta 435abb6daf ARC: RIP @running_on_hw
* No active users of this flag anymore

* flag itself was no longer usable with new simualtor which acts just like
  hardware, not providing the special chip-id = 0xffff which good old
  ISS used to do.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-10-13 14:46:17 +05:30
Vineet Gupta 1736a56f3d ARC: rename kconfig option for unaligned emulation
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-10-13 14:46:15 +05:30
Vineet Gupta d7f8a085d4 ARC: [plat*] move code out of .init_machine into common
All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-10-13 14:46:13 +05:30
Vineet Gupta 619f30188f ARC: Allow SMP kernel to build/boot on UP-only infrastructure
In light of recent SNAFU with SMP build, allow simple platform to build
as SMP but run UP.

* Remove the dependence on simulation SMP extension to enable quick
  build/test iterations of SMP kernel.

* In absence of platform SMP registration, prevent the NULL smp feature
  name from borkign the system

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-09-27 14:49:01 +05:30
Linus Torvalds 63b12bdb0d Merge branch 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc
Pull arch signal handling cleanup from Richard Weinberger:
 "This patch series moves all remaining archs to the get_signal(),
  signal_setup_done() and sigsp() functions.

  Currently these archs use open coded variants of the said functions.
  Further, unused parameters get removed from get_signal_to_deliver(),
  tracehook_signal_handler() and signal_delivered().

  At the end of the day we save around 500 lines of code."

* 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits)
  powerpc: Use sigsp()
  openrisc: Use sigsp()
  mn10300: Use sigsp()
  mips: Use sigsp()
  microblaze: Use sigsp()
  metag: Use sigsp()
  m68k: Use sigsp()
  m32r: Use sigsp()
  hexagon: Use sigsp()
  frv: Use sigsp()
  cris: Use sigsp()
  c6x: Use sigsp()
  blackfin: Use sigsp()
  avr32: Use sigsp()
  arm64: Use sigsp()
  arc: Use sigsp()
  sas_ss_flags: Remove nested ternary if
  Rip out get_signal_to_deliver()
  Clean up signal_delivered()
  tracehook_signal_handler: Remove sig, info, ka and regs
  ...
2014-08-09 09:58:12 -07:00
Linus Torvalds e853ccf08b ARC changes for 3.17
Mostly cleanup/refactoring in core intc, cache flush, IPI send...
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Merge tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC changes from Vineet Gupta:
 "Mostly cleanup/refactoring in core intc, cache flush, IPI send..."

* tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  mm, arc: remove obsolete pagefault oom killer comment
  ARC: help gcc elide icache helper for !SMP
  ARC: move common ops for line/full cache into helpers
  ARC: cache boot reporting updates
  ARC: [intc] mask/unmask can be hidden again
  ARC: [plat-arcfpga] No need for init_irq hack
  ARC: [intc] don't mask all IRQ by default
  ARC: prune extra header includes from smp.c
  ARC: update some comments
  ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)
2014-08-09 09:33:18 -07:00
Richard Weinberger 5290dd79c0 arc: Use sigsp()
Use sigsp() instead of the open coded variant.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2014-08-06 13:03:45 +02:00
Richard Weinberger f6dd2a3f1f arc: Use get_signal() signal_setup_done()
Use the more generic functions get_signal() signal_setup_done()
for signal delivery.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2014-08-06 12:56:16 +02:00
Ingo Molnar 5030c69755 Linux 3.16-rc7
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Merge tag 'v3.16-rc7' into perf/core, to merge in the latest fixes before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-28 10:00:33 +02:00
Vineet Gupta 590892deb6 ARC: [intc] mask/unmask can be hidden again
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:22:02 +05:30
Vineet Gupta 878f46c71e ARC: [intc] don't mask all IRQ by default
Hardware keeps them enabled on reset, and Linux needs to keep status quo.
Any spurious interrupts will be reported/blocked by genirq.

This helps remove a SMP IRQ quirk (next commit), where a peripheral IRQ
is hard wired to core0, and request_irq()->unmask() happens on core1,
keeping the IRQ masked on core0, needing an explicit unmask.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:17:55 +05:30
Vineet Gupta c16e3e2283 ARC: prune extra header includes from smp.c
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:17:51 +05:30
Vineet Gupta c9a98e1849 ARC: update some comments
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:17:12 +05:30
Vineet Gupta 2b75c0f93e ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)
The current cpu-private IRQ registration is ugly as it requires need to
expose arch_unmask_irq() outside of intc code.
So switch to percpu IRQ APIs:
  -request_percpu_irq [boot core]
  -enable_percpu_irq  [all cores]

Encapsulated in helper arc_request_percpu_irq()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-07-23 11:16:45 +05:30
Noam Camus 7e5122190b ARC: [SMP] Fix IPI IRQ registration
Handle it just like timer. Current request_percpu_irq() would fail on
non-boot cpus and thus IRQ will remian unmasked on those cpus.

[vgupta: fix changelong]
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-26 11:58:25 +05:30
Anton Kolesov a4b6cb735b ARC: Implement ptrace(PTRACE_GET_THREAD_AREA)
This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-26 10:14:08 +05:30
Vineet Gupta bef444a330 ARC: optimize kernel bss clearing in early boot code
using ARC ZOL which reduces tot num of instructions by half

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-26 10:14:05 +05:30
Vineet Gupta ba25915fb2 ARC: Fix build breakage for !CONFIG_ARC_DW2_UNWIND
Fixes: ec7ac6afd0 (ARC: switch to generic ENTRY/END assembler annotations)
Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-26 10:14:02 +05:30
Vineet Gupta 760ecbc7d0 ARC: fix build warning in devtree
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-23 11:50:26 +05:30
Vince Weaver 2cc9e588b0 arc, perf: Use common PMU interrupt disabled code
Transition to using the new generic PERF_PMU_CAP_NO_INTERRUPT method for
failing a sampling event when no PMU interrupt is available.

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1406150159280.16738@vincent-weaver-1.umelst.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-18 18:43:44 +02:00
Linus Torvalds 9b651cc227 Nothing too exciting here, just minor fixes/cleanup. Only noteworthy ones are:
* Moving cache disabling to early boot
 * ARC UART enabled only if earlyprintk setup in cmdline
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Merge tag 'arc-v3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC updates from Vineet Gupta:
 "Nothing too exciting here, just minor fixes/cleanup.  Only noteworthy
  ones are:

   - Moving cache disabling to early boot
   - ARC UART enabled only if earlyprintk setup in cmdline"

* tag 'arc-v3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Disable caches in early boot if so configured
  ARC: [arcfpga] Early ARC UART to be only activated by cmdline
  ARC: [arcfpga] Get rid of legacy BVCI latency unit support
  ARC: remove duplicate header exports
  ARC: arc_local_timer_setup() need not pass own cpu id
  ARC: Fixed spelling errors within comments
  ARC: make start_thread() out-of-line
  ARC: fix mmuv2 warning
  ARC: [SMP] ISS SMP extension bitrot
2014-06-09 18:05:11 -07:00
Davidlohr Bueso 5040573e49 arc: call find_vma with the mmap_sem held
Performing vma lookups without taking the mm->mmap_sem is asking for
trouble.  While doing the search, the vma in question can be modified or
even removed before returning to the caller.  Take the lock (shared) in
order to avoid races while iterating through the vmacache and/or rbtree.

[akpm@linux-foundation.org: CSE current->active_mm, per Vineet]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:00 -07:00
Vineet Gupta ef680cdc24 ARC: Disable caches in early boot if so configured
Requested-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-03 15:14:48 +05:30
Vineet Gupta 2d4899f6bd ARC: arc_local_timer_setup() need not pass own cpu id
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-06-03 13:26:52 +05:30
Rob Herring eafd370dfe Merge branch 'dt-bus-name' into for-next 2014-05-13 18:34:35 -05:00
Terence Eden f63f98ea25 ARC: Fixed spelling errors within comments
[vgupta: fixed changelong + added Randy's suggestion]
Signed-off-by: Terence Eden <github.com@shkspr.mobi>
Acked-by: Randy Dunlap <rdunlap@infradead.org>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-05-05 14:22:12 +05:30
Vineet Gupta 2ab402dfd6 ARC: make start_thread() out-of-line
Helps move out ISA specific bits from a arch exported header

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-05-05 14:22:12 +05:30
Vineet Gupta 9a091d9e84 ARC: [SMP] ISS SMP extension bitrot
* Move extension specific code out of common SMP code
* Don't enable it by default for SMP

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-05-05 14:22:12 +05:30
Vineet Gupta 8aa9e85ada ARC: !PREEMPT: Ensure Return to kernel mode is IRQ safe
There was a very small race window where resume to kernel mode from a
Exception Path (or pure kernel mode which is true for most of ARC
exceptions anyways), was not disabling interrupts in restore_regs,
clobbering the exception regs

Anton found the culprit call flow (after many sleepless nights)

| 1. we got a Trap from user land
| 2. started to service it.
| 3. While doing some stuff on user-land memory (I think it is padzero()),
|     we got a DataTlbMiss
| 4. On return from it we are taking "resume_kernel_mode" path
| 5. NEED_RESHED is not set, so we go to "return from exception" path in
|     restore regs.
| 6. there seems to be IRQ happening

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org>   #3.10, 3.12, 3.13, 3.14
Cc: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: Francois Bedard <Francois.Bedard@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-30 08:21:43 -07:00
Rob Herring 9d0c4dfedd of/fdt: update of_get_flat_dt_prop in prep for libfdt
Make of_get_flat_dt_prop arguments compatible with libfdt fdt_getprop
call in preparation to convert FDT code to use libfdt. Make the return
value const and the property length ptr type an int.

Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Stephen Chivers <schivers@csc.com>
2014-04-30 00:59:15 -05:00
Vineet Gupta c3441edd2d ARC: [SMP] General Fixes
-Pass the expected arg to non-boot park'ing routine
 (It worked so far because existing SMP backends don't use the arg)

-CONFIG_DEBUG_PREEMPT warning
2014-04-05 14:46:42 +05:30
Vineet Gupta f8b34c3fd5 ARC: [clockevent] simplify timer ISR
* Remove one liner IRQ ACK accessor, it was coming in the way of readability.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-03-26 14:31:30 +05:30
Vineet Gupta 35571f4bdc ARC: [clockevent] can't be SoC specific
So no point keeping it weak

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-03-26 14:31:29 +05:30
Vineet Gupta ec7ac6afd0 ARC: switch to generic ENTRY/END assembler annotations
With commit 9df62f0544 "arch: use ASM_NL instead of ';'" the generic
macros can handle the arch specific newline quirk. Hence we can get rid
of ARC asm macros and use the "C" style macros.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-03-26 14:31:28 +05:30
Vineet Gupta e57d339a62 ARC: [cmdline] support External Device Trees from u-boot
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-01-16 18:53:16 +05:30
Vineet Gupta 59ed941353 ARC: [cmdline] uboot cmdline handling rework
* Moved cmdline copy from asm to "C" - allows for more robust checking
  of pointer validity etc.

* Remove the Kconfig option to do so, base it on a runtime value passed
  by u-boot

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2014-01-16 18:49:38 +05:30
Vineet Gupta d8e8c7dda1 ARC: [SMP] optimize IPI send and receive
* Don't send an IPI if receiver already has a pending IPI.
  Atomically piggyback the new msg with pending msg.

* IPI receiver looping on xchg() not required

References: https://lkml.org/lkml/2013/11/25/232
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta f2a4aa5646 ARC: [SMP] simplify IPI code
* ipi_data is just a word, no need to keep it as struct

* find_next_bit() not needed to loop thru a 32bit word, ffs suffices
2013-12-23 12:05:04 +05:30
Vineet Gupta 53dc110c97 ARC: [SMP] cpu halt interface doesn't need "self" cpu-id
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta ccdaa6e0c8 ARC: [SMP] IPI ACK interface doesn't need "self" cpu-id
The interface is confusing, it feels like we are getting "sender" info,
whereas it is the "receiver", which can very well be retrived by
smp_processor_id(), if need be.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta ddf84433f4 ARC: [SMP] cpumask not needed in IPI send path
The current IPI sending callstack needlessly involves cpumask.

   arch_send_call_function_single_ipi(cpu) / smp_send_reschedule(cpu)
      ipi_send_msg(cpumask_of(cpu))	--> [cpu to cpumask]
         plat_smp_ops.ipi_send(callmap)
            for_each_cpu(callmap)	--> [cpuask to cpu]
               do_plat_specific_ipi_PER_CPU

Given that current backends are not capable of 1:N IPIs, lets simplify
the interface for now, by keeping "a" cpu all along.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-12-23 12:05:04 +05:30
Vineet Gupta da990a4f2d ARC: [perf] Fix a few thinkos
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-28 15:49:59 +05:30
Linus Torvalds dec8e46178 Final set of ARC changes for 3.13-rc1
* Support for Perf from Mischa
 * Enabling GPIO/Pinctrl drivers for Abilis TB10x platform
 * New defconfig for buildroot
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Merge tag 'arc-v3.13-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull second set of ARC changes from Vineet Gupta:
 - Support for Perf from Mischa
 - Enabling GPIO/Pinctrl drivers for Abilis TB10x platform
 - New defconfig for buildroot

* tag 'arc-v3.13-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [plat-arcfpga] Add defconfig without initramfs location
  ARC: perf: ARC 700 PMU doesn't support sampling events
  ARC: Add documentation on DT binding for ARC700 PMU
  ARC: Add perf support for ARC700 cores
  ARC: [TB10x] Updates for GPIO and pinctrl
2013-11-19 11:44:15 -08:00
Linus Torvalds 9073e1a804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual earth-shaking, news-breaking, rocket science pile from
  trivial.git"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (23 commits)
  doc: usb: Fix typo in Documentation/usb/gadget_configs.txt
  doc: add missing files to timers/00-INDEX
  timekeeping: Fix some trivial typos in comments
  mm: Fix some trivial typos in comments
  irq: Fix some trivial typos in comments
  NUMA: fix typos in Kconfig help text
  mm: update 00-INDEX
  doc: Documentation/DMA-attributes.txt fix typo
  DRM: comment: `halve' -> `half'
  Docs: Kconfig: `devlopers' -> `developers'
  doc: typo on word accounting in kprobes.c in mutliple architectures
  treewide: fix "usefull" typo
  treewide: fix "distingush" typo
  mm/Kconfig: Grammar s/an/a/
  kexec: Typo s/the/then/
  Documentation/kvm: Update cpuid documentation for steal time and pv eoi
  treewide: Fix common typo in "identify"
  __page_to_pfn: Fix typo in comment
  Correct some typos for word frequency
  clk: fixed-factor: Fix a trivial typo
  ...
2013-11-15 16:47:22 -08:00
Mischa Jonker 230c4aadcc ARC: perf: ARC 700 PMU doesn't support sampling events
The ARC 700 does not have an interrupt associated with it, and as
such it cannot trigger when a counter overflows. As the counters are
48 bit, it will usually take at least 100 days before a counter
overflows, so for mere counting of events, there is no problem.
Sampling is not supported though.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-15 10:52:28 +05:30
Linus Torvalds 10d0c9705e DeviceTree updates for 3.13. This is a bit larger pull request than
usual for this cycle with lots of clean-up.
 
 - Cross arch clean-up and consolidation of early DT scanning code.
 - Clean-up and removal of arch prom.h headers. Makes arch specific
   prom.h optional on all but Sparc.
 - Addition of interrupts-extended property for devices connected to
   multiple interrupt controllers.
 - Refactoring of DT interrupt parsing code in preparation for deferred
   probe of interrupts.
 - ARM cpu and cpu topology bindings documentation.
 - Various DT vendor binding documentation updates.
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Merge tag 'devicetree-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree updates from Rob Herring:
 "DeviceTree updates for 3.13.  This is a bit larger pull request than
  usual for this cycle with lots of clean-up.

   - Cross arch clean-up and consolidation of early DT scanning code.
   - Clean-up and removal of arch prom.h headers.  Makes arch specific
     prom.h optional on all but Sparc.
   - Addition of interrupts-extended property for devices connected to
     multiple interrupt controllers.
   - Refactoring of DT interrupt parsing code in preparation for
     deferred probe of interrupts.
   - ARM cpu and cpu topology bindings documentation.
   - Various DT vendor binding documentation updates"

* tag 'devicetree-for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (82 commits)
  powerpc: add missing explicit OF includes for ppc
  dt/irq: add empty of_irq_count for !OF_IRQ
  dt: disable self-tests for !OF_IRQ
  of: irq: Fix interrupt-map entry matching
  MIPS: Netlogic: replace early_init_devtree() call
  of: Add Panasonic Corporation vendor prefix
  of: Add Chunghwa Picture Tubes Ltd. vendor prefix
  of: Add AU Optronics Corporation vendor prefix
  of/irq: Fix potential buffer overflow
  of/irq: Fix bug in interrupt parsing refactor.
  of: set dma_mask to point to coherent_dma_mask
  of: add vendor prefix for PHYTEC Messtechnik GmbH
  DT: sort vendor-prefixes.txt
  of: Add vendor prefix for Cadence
  of: Add empty for_each_available_child_of_node() macro definition
  arm/versatile: Fix versatile irq specifications.
  of/irq: create interrupts-extended property
  microblaze/pci: Drop PowerPC-ism from irq parsing
  of/irq: Create of_irq_parse_and_map_pci() to consolidate arch code.
  of/irq: Use irq_of_parse_and_map()
  ...
2013-11-12 16:52:17 +09:00
Mischa Jonker 0dd450fe13 ARC: Add perf support for ARC700 cores
This adds basic perf support for ARC700 cores. Most PERF_COUNT_HW* events
are supported now.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-12 09:45:38 +05:30
Rob Herring b5480950c6 Merge remote-tracking branch 'grant/devicetree/next' into for-next 2013-11-07 10:34:46 -06:00
Jiang Liu 06b93c347c smp, ARC: kill SMP single function call interrupt
Commit 9a46ad6d6d "smp: make smp_call_function_many() use logic
similar to smp_call_function_single()" has unified the way to handle
single and multiple cross-CPU function calls. Now only one interrupt
is needed for architecture specific code to support generic SMP function
call interfaces, so kill the redundant single function call interrupt.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-07 14:34:31 +05:30
Vineet Gupta 7d0857a54a ARC: [SMP] Disallow RTSC
RTSC is strictly incore and must not be allowed in SMP configs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-07 14:34:31 +05:30
Vineet Gupta 57e26e5745 ARC: [SMP] Fix build failures for large NR_CPUS
ST.as only takes S9 (255) for offset. This was going out of range when
accessing a task_struct field with 4k NR_CPUS (due to 128b of coumaks
itself in there).

Workaround by using an intermediate register to do the address scaling.

There is some duplication of fix for ctx_sw.c and ctx_sw_asm.S however
given that C version will go away soon I'm not bothering to factor out
the common code.

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:46 +05:30
Vineet Gupta 5ea72a9026 ARC: [SMP] TLB flush
- Add mm_cpumask setting (aggregating only, unlike some other arches)
  used to restrict the TLB flush cross-calling

- cross-calling versions of TLB flush routines (thanks to Noam)

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:45 +05:30
Chen Gang b6fe8e7c01 arc: export symbol for pm_power_off in reset.c
Need export symbol for it, or can not pass compiling, the related error
with allmodconfig:

    MODPOST 2994 modules
  ERROR: "pm_power_off" [drivers/mfd/retu-mfd.ko] undefined!
  ERROR: "pm_power_off" [drivers/char/ipmi/ipmi_poweroff.ko] undefined!

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:44 +05:30
Chen Gang 8f146d0204 arc: export symbol for save_stack_trace() in stacktrace.c
Need export its symbol just like other architectures done, or can not
pass compiling with allmodconfig, the related error:

    MODPOST 2994 modules
  ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined!
  ERROR: "save_stack_trace" [drivers/md/persistent-data/dm-persistent-data.ko] undefined!

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:44 +05:30
Chen Gang 4782f7f9ae arc: remove '__init' for get_hw_config_num_irq()
get_hw_config_num_irq() may be called by normal iss_model_init_smp()
which is a function pointer for 'init_smp' which may be called by
first_lines_of_secondary() which also need be normal too.

The related warning (with allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x5814): Section mismatch in reference from the function iss_model_init_smp() to the function .init.text:get_hw_config_num_irq()
  The function iss_model_init_smp() references
  the function __init get_hw_config_num_irq().
  This is often because iss_model_init_smp lacks a __init
  annotation or the annotation of get_hw_config_num_irq is wrong.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
2013-11-06 10:41:43 +05:30
Chen Gang 8f5d221b06 arc: remove '__init' for first_lines_of_secondary()
first_lines_of_secondary() is a '__init' function, but it may be called
by __cpu_up() by _cpu_up() by cpu_up() which is a normal export symbol
function. So recommend to remove '__init'.

The related warning (with allmodconfig):

    MODPOST vmlinux.o
  WARNING: vmlinux.o(.text+0x315c): Section mismatch in reference from the function __cpu_up() to the function .init.text:first_lines_of_secondary()
  The function __cpu_up() references
  the function __init first_lines_of_secondary().
  This is often because __cpu_up lacks a __init
  annotation or the annotation of first_lines_of_secondary is wrong.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
2013-11-06 10:41:43 +05:30
Chen Gang 3d01c1ce41 arc: kgdb: add default implementation for kgdb_roundup_cpus()
arc supports kgdb, but need update -- add function kgdb_roundup_cpus(),
or can not pass compiling. At present, add the simple generic one just
like other architectures(e.g. tile, mips ...).

The related error (with allmodconfig):

  kernel/built-in.o: In function `kgdb_cpu_enter':
  kernel/debug/debug_core.c:580: undefined reference to `kgdb_roundup_cpus'

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:41 +05:30
Vineet Gupta 0dafafc3ef ARC: Add support for irqflags tracing and lockdep
Lockdep required a small fix to stacktrace API which was incorrectly
unwindign out of __switch_to for the current call frame.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:40 +05:30
Vineet Gupta 54c8bff14d ARC: Reset the value of Interrupt Priority Register
In case bootloader has changed the priority of one/more IRQ lines

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:40 +05:30
Vineet Gupta 07ba69a46c ARC: Reduce #ifdef'ery for unaligned access emulation
Emulation not enabled is treated as if the fixup failed, so no need for
special #ifdef checks.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:39 +05:30
Vineet Gupta 21a63b5604 ARC: Change calling convention of do_page_fault()
switch the args (address, pt_regs) to match with all the other "C"
exception handlers.

This removes the awkwardness in EV_ProtV for page fault vs. unaligned
access.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:41:39 +05:30
Vineet Gupta 064a626924 ARC: use __weak instead of __attribute__((weak))
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:40:37 +05:30
Vineet Gupta 8e457d6a75 ARC: Annotate some functions as static
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-11-06 10:40:37 +05:30
Christoph Lameter 6855e95ce3 arc: Replace __get_cpu_var uses
__get_cpu_var() is used for multiple purposes in the kernel source. One of them is
address calculation via the form &__get_cpu_var(x). This calculates the address for
the instance of the percpu variable of the current processor based on an offset.

Other use cases are for storing and retrieving data from the current processors percpu area.
__get_cpu_var() can be used as an lvalue when writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store and retrieve operations
could use a segment prefix (or global register on other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a percpu area and use
optimized assembly code to read and write per cpu variables.

This patch converts __get_cpu_var into either an explicit address calculation using this_cpu_ptr()
or into a use of this_cpu operations that use the offset. Thereby address calcualtions are avoided
and less registers are used when code is generated.

At the end of the patchset all uses of __get_cpu_var have been removed so the macro is removed too.

The patchset includes passes over all arches as well. Once these operations are used throughout then
specialized macros can be defined in non -x86 arches as well in order to optimize per cpu access by
f.e. using a global register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu variable.

	DEFINE_PER_CPU(int, u);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(this_cpu_ptr(&x), y, sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
2013-11-06 10:40:37 +05:30
Anoop Thomas Mathew 23d6d3db66 doc: typo on word accounting in kprobes.c in mutliple architectures
Signed-off-by: Anoop Thomas Mathew <atm@profoundis.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-10-14 15:46:39 +02:00
Vineet Gupta 5b24282846 ARC: Ignore ptrace SETREGSET request for synthetic register "stop_pc"
ARCompact TRAP_S insn used for breakpoints, commits before exception is
taken (updating architectural PC). So ptregs->ret contains next-PC and
not the breakpoint PC itself. This is different from other restartable
exceptions such as TLB Miss where ptregs->ret has exact faulting PC.
gdb needs to know exact-PC hence ARC ptrace GETREGSET provides for
@stop_pc which returns ptregs->ret vs. EFA depending on the
situation.

However, writing stop_pc (SETREGSET request), which updates ptregs->ret
doesn't makes sense stop_pc doesn't always correspond to that reg as
described above.

This was not an issue so far since user_regs->ret / user_regs->stop_pc
had same value and both writing to ptregs->ret was OK, needless, but NOT
broken, hence not observed.

With gdb "jump", they diverge, and user_regs->ret updating ptregs is
overwritten immediately with stop_pc, which this patch fixes.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-12 12:00:36 +05:30
Rob Herring be5973117b arc: remove unnecessary prom.h includes
Remove unnecessary prom.h includes in preparation to remove prom.h.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
2013-10-09 20:04:01 -05:00
Rob Herring 880beb8807 arc: use common of_flat_dt_match_machine
Convert arc to use the common of_flat_dt_match_machine function.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-09 20:03:55 -05:00
Rob Herring ad81fcb530 arc: use early_init_dt_scan
Convert arc to use new early_init_dt_scan function.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-09 11:38:08 -05:00
Rob Herring 1efc959e0b arc: use unflatten_and_copy_device_tree
Use the common unflatten_and_copy_device_tree to copy the built-in FDT
out of init section.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
2013-10-09 11:38:03 -05:00
Christian Ruppert 10469350e3 ARC: Fix signal frame management for SA_SIGINFO
Previously, when a signal was registered with SA_SIGINFO, parameters 2
and 3 of the signal handler were written to registers r1 and r2 before
the register set was saved. This led to corruption of these two
registers after returning from the signal handler (the wrong values were
restored).
With this patch, registers are now saved before any parameters are
passed, thus maintaining the processor state from before signal entry.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-10-03 09:43:56 +05:30
Uwe Kleine-König 55c2e26204 ARC: Use clockevents_config_and_register over clockevents_register_device
clockevents_config_and_register is more clever and correct than doing it
by hand; so use it.

[vgupta: fixed build failure due to missing ; in patch]

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-27 16:28:48 +05:30
Mischa Jonker c11eb222fd ARC: Handle zero-overhead-loop in unaligned access handler
If a load or store is the last instruction in a zero-overhead-loop, and
it's misaligned, the loop would execute only once.

This fixes that problem.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-27 16:28:23 +05:30
Noam Camus c3567f8a35 ARC: SMP failed to boot due to missing IVT setup
Commit 05b016ecf5 "ARC: Setup Vector Table Base in early boot" moved
the Interrupt vector Table setup out of arc_init_IRQ() which is called
for all CPUs, to entry point of boot cpu only, breaking booting of others.

Fix by adding the same to entry point of non-boot CPUs too.

read_arc_build_cfg_regs() printing IVT Base Register didn't help the
casue since it prints a synthetic value if zero which is totally bogus,
so fix that to print the exact Register.

[vgupta: Remove the now stale comment from header of arc_init_IRQ and
also added the commentary for halt-on-reset]

Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Cc: <stable@vger.kernel.org> #3.11
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 07:40:08 -07:00
Linus Torvalds 31f7c3a688 Device tree core updates for v3.12
Generally minor changes. A bunch of bug fixes, particularly for
 initialization and some refactoring. Most notable change if feeding the
 entire flattened tree into the random pool at boot. May not be
 significant, but shouldn't hurt either.
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Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

Pull device tree core updates from Grant Likely:
 "Generally minor changes.  A bunch of bug fixes, particularly for
  initialization and some refactoring.  Most notable change if feeding
  the entire flattened tree into the random pool at boot.  May not be
  significant, but shouldn't hurt either"

Tim Bird questions whether the boot time cost of the random feeding may
be noticeable.  And "add_device_randomness()" is definitely not some
speed deamon of a function.

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
  of/platform: add error reporting to of_amba_device_create()
  irq/of: Fix comment typo for irq_of_parse_and_map
  of: Feed entire flattened device tree into the random pool
  of/fdt: Clean up casting in unflattening path
  of/fdt: Remove duplicate memory clearing on FDT unflattening
  gpio: implement gpio-ranges binding document fix
  of: call __of_parse_phandle_with_args from of_parse_phandle
  of: introduce of_parse_phandle_with_fixed_args
  of: move of_parse_phandle()
  of: move documentation of of_parse_phandle_with_args
  of: Fix missing memory initialization on FDT unflattening
  of: consolidate definition of early_init_dt_alloc_memory_arch()
  of: Make of_get_phy_mode() return int i.s.o. const int
  include: dt-binding: input: create a DT header defining key codes.
  of/platform: Staticize of_platform_device_create_pdata()
  of: Specify initrd location using 64-bit
  dt: Typo fix
  OF: make of_property_for_each_{u32|string}() use parameters if OF is not enabled
2013-09-10 13:53:52 -07:00
Mischa Jonker 8508d5653f ARC: remove console_verbose() from setup_arch()
It prevents kernel parameters such as 'loglevel' from doing their job.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 10:31:12 +05:30
Noam Camus 7d669a193b ARC: Handle un-aligned user space access in BE.
Adding endian awarness to un-aligned access exception handling.

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-09-05 10:31:11 +05:30
Grant Likely a1727da599 of: consolidate definition of early_init_dt_alloc_memory_arch()
Most architectures use the same implementation. Collapse the common ones
into a single weak function that can be overridden.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
2013-08-28 21:18:32 +01:00
Vineet Gupta fce16bc35a ARC: Entry Handler tweaks: Optimize away redundant IRQ_DISABLE_SAVE
In the exception return path, for both U/K cases, intr are already
disabled (for various existing reasons). So when we drop down to
@restore_regs, we need not redo that.

There was subtle issue - when intr were NOT being disabled for
ret-to-kernel-but-no-preemption case - now fixed by moving the
IRQ_DISABLE further up in @resume_kernel_mode.

So what do we gain:

* Shaves off a few insn in return path.

* Eliminates the need for IRQ_DISABLE_SAVE assembler macro for ARCv2
  hence allows for entry code sharing.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:25 +05:30
Vineet Gupta 37f3ac498c ARC: Exception Handlers Code consolidation
After the recent cleanups, all the exception handlers now have same
boilerplate prologue code. Move that into common macro.

This reduces readability but helps greatly with sharing / duplicating
entry code with ARCv2 ISA where the handlers are pretty much the same,
just the entry prologue is different (due to hardware assist).

Also while at it, add the missing FAKE_RET_FROM_EXCPN calls in couple of
places to drop down to pure kernel mode (from exception mode) before
jumping off into "C" code.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:25 +05:30
Vineet Gupta fe240f11cd ARC: Add some .gitignore entries
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-08-26 09:40:24 +05:30
Linus Torvalds 76d3f4c27d ARC changes for 3.11
Highlights of changes:
 
 -Continuation of ARC MM changes from 3.10 including
    zero page optimization;
    Setting pagecache pages dirty by default;
    Non executable stack by default;
    Reducing dcache flushes for aliasing VIPT config
 
 -Long overdue rework of pt_regs machinery - removing the unused word gutters
  and adding ECR register to baseline (helps cleanup lot of low level code)
 
 -Support for ARC gcc 4.8
 
 -Few other preventive fixes, cosmetics, usage of Kconfig helper..
 
 The diffstat is larger than normal primarily because of arcregs.h header split
 as well as beautification of macros in entry.h
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Merge tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull first batch of ARC changes from Vineet Gupta:
 "There's a second bunch to follow next week - which depends on commits
  on other trees (irq/net).  I'd have preferred the accompanying ARC
  change via respective trees, but it didn't workout somehow.

  Highlights of changes:

   - Continuation of ARC MM changes from 3.10 including

       zero page optimization
       Setting pagecache pages dirty by default
       Non executable stack by default
       Reducing dcache flushes for aliasing VIPT config

   - Long overdue rework of pt_regs machinery - removing the unused word
     gutters and adding ECR register to baseline (helps cleanup lot of
     low level code)

   - Support for ARC gcc 4.8

   - Few other preventive fixes, cosmetics, usage of Kconfig helper..

  The diffstat is larger than normal primarily because of arcregs.h
  header split as well as beautification of macros in entry.h"

* tag 'arc-v3.11-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (32 commits)
  ARC: warn on improper stack unwind FDE entries
  arc: delete __cpuinit usage from all arc files
  ARC: [tlb-miss] Fix bug with CONFIG_ARC_DBG_TLB_MISS_COUNT
  ARC: [tlb-miss] Extraneous PTE bit testing/setting
  ARC: Adjustments for gcc 4.8
  ARC: Setup Vector Table Base in early boot
  ARC: Remove explicit passing around of ECR
  ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
  ARC: stop using pt_regs->orig_r8
  ARC: pt_regs update #4: r25 saved/restored unconditionally
  ARC: K/U SP saved from one location in stack switching macro
  ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
  ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
  ARC: Increase readability of entry handlers
  ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
  ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
  ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
  ARC: pt_regs update #0: remove kernel stack canary
  ARC: [mm] Remove @write argument to do_page_fault()
  ARC: [mm] Make stack/heap Non-executable by default
  ...
2013-07-03 11:09:27 -07:00
Al Viro e77e430033 more open-coded file_inode() calls
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:21 +04:00
Vineet Gupta baadb8fd0c ARC: warn on improper stack unwind FDE entries
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:59 +05:30
Paul Gortmaker ce7599567e arc: delete __cpuinit usage from all arc files
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/arc uses of the __cpuinit macros from
all C files.  Currently arc does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:37:58 +05:30
Vineet Gupta 5a45da02cf ARC: Adjustments for gcc 4.8
* DWARF unwinder related
  + Force DWARF2 compliant .debug_frame (gcc 4.8 defaults to DWARF4
    which kernel unwinder can't grok).
  + Discard the additional .eh_frame generated
  + Discard the dwarf4 debug info generated by -gdwarf-2 for normal
    no debug case

* 4.8 already uses arc600 multilibs for -mno-mpy

* switch to using uclibc compiler (to get -mmedium-calls and -mno-sdata)
  and also since buildroot can only use 1 toolchain

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:35:32 +05:30
Vineet Gupta 05b016ecf5 ARC: Setup Vector Table Base in early boot
Otherwise early boot exceptions such as instructions errors due to
configuration mismatch between kernel and hardware go off to la-la land,
as opposed to hitting the handler and panic()'ing properly.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 15:30:51 +05:30
Vineet Gupta 38a9ff6d24 ARC: Remove explicit passing around of ECR
With ECR now part of pt_regs

* No need to propagate from lowest asm handlers as arg
* No need to save it in tsk->thread.cause_code
* Avoid bit chopping to access the bit-fields

More code consolidation, cleanup

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 15:30:50 +05:30
Vineet Gupta 502a0c775c ARC: pt_regs update #5: Use real ECR for pt_regs->event vs. synth values
pt_regs->event was set with artificial values to identify the low level
system event (syscall trap / breakpoint trap / exceptions / interrupts)

With r8 saving out of the way, the full word can be used to save real
ECR (Exception Cause Register) which helps idenify the event naturally,
including additional info such as cause code, param.
Only for Interrupts, where ECR is not applicable, do we resort to
synthetic non ECR values.

SAVE_ALL_TRAP/EXCEPTIONS can now be merged as they both use ECR with
different runtime values.

The ptrace helpers now use the sub-fields of ECR to distinguish the
events (e.g. vector 0x25 is trap, param 0 is syscall...)

The following benefits will follow:

(1) This centralizes the location of where ECR is saved and will allow
    the cleanup of task->thread.cause_code ECR placeholder which is set
    in non-uniform way. Then ARC VM code can safely rely on it being
    there for purpose of finer grained VM_EXEC dcache flush (based on
    exec fault: I-TLB Miss)

(2) Further, ECR being passed around from low level handlers as arg can
    be eliminated as it is part of standard reg-file in pt_regs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-26 14:04:48 +05:30
Vineet Gupta 359105bdb0 ARC: pt_regs update #4: r25 saved/restored unconditionally
(This is a VERY IMP change for low level interrupt/exception handling)

-----------------------------------------------------------------------
WHAT
-----------------------------------------------------------------------
* User 25 now saved in pt_regs->user_r25 (vs. tsk->thread_info.user_r25)

* This allows Low level interrupt code to unconditionally save r25
  (vs. the prev version which would only do it for U->K transition).
  Ofcourse for nested interrupts, only the pt_regs->user_r25 of
  bottom-most frame is useful.

* simplifies the interrupt prologue/epilogue

* Needed for ARCv2 ISA code and done here to keep design similar with
  ARCompact event handling

-----------------------------------------------------------------------
WHY
-------------------------------------------------------------------------
With CONFIG_ARC_CURR_IN_REG, r25 is used to cache "current" task pointer
in kernel mode. So when entering kernel mode from User Mode
- user r25 is specially safe-kept (it being a callee reg is NOT part of
  pt_regs which are saved by default on each interrupt/trap/exception)
- r25 loaded with current task pointer.

Further, if interrupt was taken in kernel mode, this is skipped since we
know that r25 already has valid "current" pointer.

With 2 level of interrupts in ARCompact ISA, detecting this is difficult
but still possible, since we could be in kernel mode but r25 not already saved
(in fact the stack itself might not have been switched).

A. User mode
B. L1 IRQ taken
C. L2 IRQ taken (while on 1st line of L1 ISR)

So in #C, although in kernel mode, r25 not saved (infact SP not
switched at all)

Given that ARcompact has manual stack switching, we could use a bit of
trickey - The low level code would make sure that SP is only set to kernel
mode value at the very end (after saving r25). So a non kernel mode SP,
even if in kernel mode, meant r25 was NOT saved.

The same paradigm won't work in ARCv2 ISA since SP is auto-switched so
it's setting can't be delayed/constrained.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:25 +05:30
Vineet Gupta 147aece29b ARC: Entry Handler tweaks: Simplify branch for in-kernel preemption
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:24 +05:30
Vineet Gupta 1898a959b7 ARC: Entry Handler tweaks: Avoid hardcoded LIMMS for ECR values
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:23 +05:30
Vineet Gupta 3ebedbb2fd ARC: Increase readability of entry handlers
* use artificial PUSH/POP contructs for CORE Reg save/restore to stack
* use artificial PUSHAX/POPAX contructs for Auxiliary Space regs
* macro'ize multiple copies of callee-reg-save/restore (SAVE_R13_TO_R24)
* use BIC insn for inverse-and operation

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:23 +05:30
Vineet Gupta 16f9afe651 ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
This is trickier than prev two:

* context switching code saves kernel mode callee regs in the format of
  struct callee_regs thus needs adjustment. This also reduces the height
  of topmost kernel stack frame by 1 word.

* Since kernel stack unwinder is sensitive to height of topmost kernel
  stack frame, that needs a word of adjustment too.

ptrace needs a bit of updating since pt_regs now diverges from
user_regs_struct.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:22 +05:30
Vineet Gupta 2fa919045b ARC: pt_regs update #2: Remove unused gutter at start of pt_regs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:22 +05:30
Vineet Gupta 283237a04f ARC: pt_regs update #1: Align pt_regs end with end of kernel stack page
Historically, pt_regs would end at offset of 1 word from end of stack
page.

        -----------------  -> START of page (task->stack)
        |               |
        | thread_info   |
        -----------------
        |               |
   ^    ~               ~
   |    ~               ~
   |    |               |
   |    |               | <---- pt_regs used to END here
        -----------------
        | 1 word GUTTER |
        ----------------- -> End of page (START of kernel stack)

This required special "one-off" considerations in low level code.

The root cause is very likely assumption of "empty" SP by the original
ARC kernel hackers, despite ARC700 always been "full" SP.

So finally RIP one word gutter !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:21 +05:30
Vineet Gupta 3e1ae44188 ARC: [mm] Remove @write argument to do_page_fault()
This can be ascertained within do_page_fault() since it gets the full
ECR (Exception Cause Register).

Further, for both the callers of do_page_fault(): Prot-V / D-TLB-Miss,
the cause sub-fields in ECR are same for same type of access, making the
code much more simpler.

D-TLB-Miss [LD] 0x00_21_01_00
Prot-V     [LD] 0x00_23_01_00
                        ^^
D-TLB-Miss [ST] 0x00_21_02_00
Prot-V     [ST] 0x00_23_02_00
                        ^^
D-TLB-Miss [EX] 0x00_21_03_00
Prot-V     [EX] 0x00_23_03_00
                        ^^

This helps code consolidation, which is even better when moving code from
assembler to "C".

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:20 +05:30
Vineet Gupta 6546415226 ARC: Reduce Code for ECR printing
Cause codes are same for D-TLB-Miss and Prot-V

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta da1677b02d ARC: Disintegrate arcregs.h
* Move the various sub-system defines/types into relevant files/functions
  (reduces compilation time)

* move CPU specific stuff out of asm/tlb.h into asm/mmu.h

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta 18437347b9 ARC: More code beautification with IS_ENABLED()
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Vineet Gupta 8235703e10 ARC: Use kconfig helper IS_ENABLED() to get rid of defines.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:42 +05:30
Linus Torvalds e30f419245 ARC port updates for Linux 3.10 (part 1)
* Support for two new platforms based on ARC700
  - Abilis TB10x SoC [Chritisian/Pierrick]
  - Simulator only System-C Model [Mischa]
 
 * ARC specific MM improvements
  - Avoid full TLB flush (ASID increment) on munmap (even single page)
  - VIPT Cache Flushing improvements
    + Delayed dcache flush for non-aliasing dcache (big performance boost)
    + icache flush aliasing agnostic (no need to kill all possible aliases)
 
 * Others
  - Avoid needless rebuild of DTB files for every kernel build
  - Remove builtin cmdline as that is already provided by DeviceTree/bootargs
  - Fixing unaligned access emulation corner case
  - checkpatch fixes [Sachin]
  - Various fixlets [Noam]
  - Minor build failures/cleanups
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Merge tag 'arc-v3.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC port updates from Vineet Gupta:
 "Support for two new platforms based on ARC700:
   - Abilis TB10x SoC [Chritisian/Pierrick]
   - Simulator only System-C Model [Mischa]

  ARC specific MM improvements:
   - Avoid full TLB flush (ASID increment) on munmap (even single page)
   - VIPT Cache Flushing improvements
     + Delayed dcache flush for non-aliasing dcache (big performance boost)
     + icache flush aliasing agnostic (no need to kill all possible aliases)

  Others:
   - Avoid needless rebuild of DTB files for every kernel build
   - Remove builtin cmdline as that is already provided by DeviceTree/bootargs
   - Fixing unaligned access emulation corner case
   - checkpatch fixes [Sachin]
   - Various fixlets [Noam]
   - Minor build failures/cleanups"

* tag 'arc-v3.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (35 commits)
  ARC: [mm] Lazy D-cache flush (non aliasing VIPT)
  ARC: [mm] micro-optimize page size icache invalidate
  ARC: [mm] remove the pessimistic all-alias-invalidate icache helpers
  ARC: [mm] consolidate icache/dcache sync code
  ARC: [mm] optimise icache flush for kernel mappings
  ARC: [mm] optimise icache flush for user mappings
  ARC: [mm] optimize needless full mm TLB flush on munmap
  ARC: Add support for nSIM OSCI System C model
  ARC: [TB10x] Adapt device tree to new compatible string
  ARC: [TB10x] Add support for TB10x platform
  ARC: [TB10x] Device tree of TB100 and TB101 Development Kits
  ARC: Prepare interrupt code for external controllers
  ARC: Allow embedded arc-intc to be properly placed in DT intc hierarchy
  ARC: [cmdline] Don't overwrite u-boot provided bootargs
  ARC: [cmdline] Remove CONFIG_CMDLINE
  ARC: [plat-arcfpga] defconfig update
  ARC: unaligned access emulation broken if callee-reg dest of LD/ST
  ARC: unaligned access emulation error handling consolidation
  ARC: Debug/crash-printing Improvements
  ARC: fix typo with clock speed
  ...
2013-05-09 14:36:27 -07:00
Christian Ruppert a37cdacc9b ARC: Prepare interrupt code for external controllers
This patch adds some room for CPU-external interrupt controllers in the
Linux interrupt space. Until now, only the 32 CPU internal interrupt lines
were supported which does not allow for external interrupt controllers such
as GPIO modules etc.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:58 +05:30
Vineet Gupta c93d8b8c78 ARC: Allow embedded arc-intc to be properly placed in DT intc hierarchy
arc-intc is initialized in arc common code as it is applicable to all
platforms. However platforms with their own external intc still need to
refer to it for correct DT interrupt tree hierarchy setup,

e.g.
static struct of_device_id __initdata tb10x_irq_ids[] = {
	{ .compatible = "snps,arc700-intc", .data = dummy_init_irq },
	{ .compatible = "abilis,tb10x_ictl", .data = tb10x_init_irq },
	{},
};

The fix is to use the generic irqchip framework to tie all irqchips in
a special linker section and then call irqchip_init() which calls the
DT of_irq_init() for all the intc in one go.

That way the platform code need not be aware of arc-intc at all.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:57 +05:30
Vineet Gupta 9593a933d5 ARC: [cmdline] Don't overwrite u-boot provided bootargs
The existing code was wrong on several counts:

* uboot provided bootargs were copied into @boot_command_line, only to
  be over-written by setup_machine_fdt(), effectively lost

* @cmdline_p returned by setup_arch() to start_kernel() didn't include
  the DT /bootargs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:57 +05:30
Vineet Gupta 6971881f2a ARC: [cmdline] Remove CONFIG_CMDLINE
Given that DeviceTree /bootargs can provide similar functionality,
no point in providing duplicate infrastructure.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:56 +05:30
Vineet Gupta ce147c7445 ARC: unaligned access emulation broken if callee-reg dest of LD/ST
The fixup code correctly updates the callee-regs on stack, but
fails to unwind it into actual register file. Thus userspace won't see
the update.

Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:55 +05:30
Vineet Gupta c723ea4620 ARC: unaligned access emulation error handling consolidation
If CONFIG_ARC_MISALIGN_ACCESS is not enabled, or if the fixup fails,
call the same error handler: same signal/si_code to user (SIGBUS)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:55 +05:30
Vineet Gupta bd3c8b11ec ARC: Debug/crash-printing Improvements
* Remove the line-break between scratch/callee-regs (sneaked in when we
  converted from printk to pr_*

* Use %pS to print the symbol names of faulting PC (ret pseudo register)
  and BLINK (call return register)

* Don't print user-vma for a kernel crash (only do it for
  print-fatal-signals based regfile dump)

* Verbose print the Interrupt/Exception Enable/Active state

* for main executable link address is 0x10000 based (vs. 0) thus offset
  of faulting PC needs to be adjusted

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Noam Camus 68e4790ec4 ARC: fix typo with clock speed
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Vineet Gupta 681a90ffe8 arc, print-fatal-signals: reduce duplicated information
After the recent generic debug info on dump_stack() and friends, arc
is printing duplicate information on debug dumps.

 [ARCLinux]$ ./crash
 crash/50: potentially unexpected fatal signal 11.	<-- [1]
 /sbin/crash, TGID 50					<-- [2]
 Pid: 50, comm: crash Not tainted 3.9.0-rc4+ #132 	<-- [3]
 ...

Remove them.

[tj@kernel.org: updated patch desc]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo a43cb95d54 dump_stack: unify debug information printed by show_regs()
show_regs() is inherently arch-dependent but it does make sense to print
generic debug information and some archs already do albeit in slightly
different forms.  This patch introduces a generic function to print debug
information from show_regs() so that different archs print out the same
information and it's much easier to modify what's printed.

show_regs_print_info() prints out the same debug info as dump_stack()
does plus task and thread_info pointers.

* Archs which didn't print debug info now do.

  alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
  metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
  um, xtensa

* Already prints debug info.  Replaced with show_regs_print_info().
  The printed information is superset of what used to be there.

  arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* s390 is special in that it used to print arch-specific information
  along with generic debug info.  Heiko and Martin think that the
  arch-specific extra isn't worth keeping s390 specfic implementation.
  Converted to use the generic version.

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

 kernel BUG at /work/os/work/kernel/workqueue.c:4841!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
 RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
 RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
 RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
  0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
  ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
 Call Trace:
  [<ffffffff81000312>] do_one_initcall+0x122/0x170
  [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  [<ffffffff81c4776e>] kernel_init+0xe/0xf0
  [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  ...

v2: Typo fix in x86-32.

v3: CPU number dropped from show_regs_print_info() as
    dump_stack_print_info() has been updated to print it.  s390
    specific implementation dropped as requested by s390 maintainers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>		[tile bits]
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Tejun Heo 196779b9b4 dump_stack: consolidate dump_stack() implementations and unify their behaviors
Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a071>] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
Linus Torvalds 5d434fcb25 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual stuff, mostly comment fixes, typo fixes, printk fixes and small
  code cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits)
  mm: Convert print_symbol to %pSR
  gfs2: Convert print_symbol to %pSR
  m32r: Convert print_symbol to %pSR
  iostats.txt: add easy-to-find description for field 6
  x86 cmpxchg.h: fix wrong comment
  treewide: Fix typo in printk and comments
  doc: devicetree: Fix various typos
  docbook: fix 8250 naming in device-drivers
  pata_pdc2027x: Fix compiler warning
  treewide: Fix typo in printks
  mei: Fix comments in drivers/misc/mei
  treewide: Fix typos in kernel messages
  pm44xx: Fix comment for "CONFIG_CPU_IDLE"
  doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP"
  mmzone: correct "pags" to "pages" in comment.
  kernel-parameters: remove outdated 'noresidual' parameter
  Remove spurious _H suffixes from ifdef comments
  sound: Remove stray pluses from Kconfig file
  radio-shark: Fix printk "CONFIG_LED_CLASS"
  doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE
  ...
2013-04-30 09:36:50 -07:00
Vineet Gupta 30ecee8cdd ARC: [build] Fix warnings with CONFIG_DEBUG_SECTION_MISMATCH
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:27:00 +05:30
Christian Ruppert 5b00029e30 ARC: [build] Build failure with !KPROBES
arch/arc/kernel/traps.c no longer compiles without explicitly including
asm/kprobes.h

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:26:50 +05:30
Sachin Kamat e420c82d09 ARC: Remove duplicate inclusion of header files
Some header files were included twice in the same file.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Sachin Kamat 955ad5959f ARC: Fix coding style issues
Fixes the following coding style issues as detected by checkpatch:
ERROR: space required before the open parenthesis '('
ERROR: "foo * bar" should be "foo *bar"
WARNING: space prohibited between function name and open parenthesis '('
WARNING: please, no spaces at the start of a line

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:14 +05:30
Sachin Kamat 1ec9db1056 ARC: Use <linux/*> headers instead of <asm/*>
Silences the following checkpatch warnings:
WARNING: Use #include <linux/ptrace.h> instead of <asm/ptrace.h>
WARNING: Use #include <linux/kprobes.h> instead of <asm/kprobes.h>
WARNING: Use #include <linux/kgdb.h> instead of <asm/kgdb.h>
WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
WARNING: Use #include <linux/cache.h> instead of <asm/cache.h>

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:14 +05:30
Thomas Gleixner fa35e42a00 arc: Use generic idle loop
The generic idle loop implements all functionality. Aside of that it
allows arc to implement the tsk_is_polling() functionality correctly,
despite the patently (now gone) comment in the original arc cpu_idle()
function:
/* Since we SLEEP in idle loop, TIF_POLLING_NRFLAG can't be set */
See kernel/cpu/idle.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Tested-by: Vineet Gupta <vgupta@synopsys.com>
Link: http://lkml.kernel.org/r/20130321215233.711253792@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-08 17:39:23 +02:00
Vineet Gupta 367f3fcd92 ARC: Fix the typo in event identifier flags used by ptrace
orig_r8_IS_EXCPN and orig_r8_IS_BRKPT were same values due to a
copy/paste error. Although it looks bad and is wrong, it really doesn't
affect gdb working.

orig_r8_IS_BRKPT is the one relevant to debugging (breakpoints), since
it is used to provide EFA vs. ERET to a ptrace "stop_pc" request.

So when gdb has inserted a breakpoint, orig_r8_IS_BRKPT is already set,
and anything else (i.e. orig_r8_IS_EXCPN) becoming same as it, really
doesn't hurt gdb. The corollary case, could be nasty but nobody uses the
ptrace "stop_pc" request in that case

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-20 18:45:45 +05:30
Paul Bolle b237ba8f47 arc: fix incorrect ifdef comment
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-18 11:01:16 +01:00
Vineet Gupta 180d406e49 ARC: ABIv3: fork/vfork wrappers not needed in "no-legacy-syscall" ABI
When switching to clone() only ABI - I missed out pruning the low level
asm syscall wrappers

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-11 19:01:10 +05:30
Vineet Gupta 8ff14bbc6a ARC: ABIv3: Print the correct ABI ver
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-11 19:01:09 +05:30
Vineet Gupta 1540c85b17 ARC: make allyesconfig build breakages
CC      drivers/mmc/host/mmc_spi.o
drivers/mmc/host/mmc_spi.c:118: error: redefinition of 'struct scratch'
make[3]: *** [drivers/mmc/host/mmc_spi.o] Error 1
make[2]: *** [drivers/mmc/host] Error 2
make[1]: *** [drivers/mmc] Error 2
make: *** [drivers] Error 2

  CC      arch/arc/kernel/kgdb.o
In file included from include/linux/kgdb.h:20,
                 from arch/arc/kernel/kgdb.c:11:
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: 'struct pt_regs' declared inside parameter list
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: its scope is only this definition or declaration, which is
probably not what you want
arch/arc/kernel/kgdb.c:172: error: conflicting types for 'kgdb_trap'

  CC      arch/arc/kernel/kgdb.o
arch/arc/kernel/kgdb.c: In function 'pt_regs_to_gdb_regs':
arch/arc/kernel/kgdb.c:62: error: dereferencing pointer to incomplete
type

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-11 19:01:09 +05:30
Vineet Gupta 17139053eb ARC: Fixup the current ABI version
The upstream kernel ABI (v3) is different from current out-of-tree (v2):
* no-legacy-syscalls
* user_regs_struct layout has changed

So we rev up the ABI version

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-27 20:00:25 +05:30
Vineet Gupta eab6a08c08 ARC: make a copy of flat DT
The flat DT (currently embedded in vmlinux) is in .init section.
The unflattened/binary tree doesn't copy strings through and references
them from orig flat DT - which could cause catestrohpy if of_* APIs are
called post init, say from a driver which is a loadable module.

Reported-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-26 14:25:18 +05:30
Vineet Gupta 3eb3e7dd53 ARC: Fix pt_orig_r8 access
Syscall restarting fixes made pt_regs->orig_r8 a short word, which was
not reflected in the assembler code - thus could potentially break gdb
debugging.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:21 +05:30
Vineet Gupta 7f85e5ec0d ARC: [3.9] Fallout of hlist iterator update
Commit 0bbacca "hlist: drop the node parameter from iterators" changed
the iterator across the board - but ARC port being out-of-tree missed
it.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:20 +05:30
Vineet Gupta 1e26662993 ARC: 64bit RTSC timestamp hardware issue
The 64bit RTSC is not reliable, causing spurious "jumps" in higher word,
making Linux timekeeping go bonkers. So as of now just use the lower
32bit timestamp.

A cleaner approach would have been removing RTSC support altogether as the
32bit RTSC is equivalent to old TIMER1 based solution, but some customers
can use the 32bit RTSC in SMP syn fashion (vs. TIMER1 which being incore
can't be done easily).

A fallout of this is sched_clock()'s hardware assisted version needs to
go away since it can't use 32bit wrapping counter - instead we use the
generic "weak" jiffies based version.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:20 +05:30
Vineet Gupta 10b1271875 ARC: [Review] Multi-platform image #7: SMP common code to use callbacks
This again is for switch from singleton platform SMP API to
multi-platform paradigm

Platform code is not yet setup to populate the callbacks, that happens
in next commit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:16 +05:30
Vineet Gupta e97ff121ae ARC: [Review] Multi-platform image #4: Isolate platform headers
-Top level ARC makefile removes -I for platform headers
-asm/irq.h no longer includes plat/irq.h

-platform makefile adds -I for it's specfic platform headers
-platform code to directly include it's plat/irq.h

-Linker script needed plat/memmap.h for CCM info, already in .config

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:14 +05:30
Vineet Gupta 877768c84d ARC: [Review] Multi-platform image #3: switch to board callback
-platform API is retired and instead callbacks are used

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:14 +05:30
Vineet Gupta 03a6d28cdd ARC: [Review] Multi-platform image #2: Board callback Infrastructure
The orig platform code orgnaization was singleton design pattern - only
one platform (and board thereof) would build at a time.

Thus any platform/board specific code (e.g. irq init, early init ...)
expected by ARC common code was exported as well defined set of APIs,
with only ONE instance building ever.

Now with multiple-platform build requirement, that design of code no
longer holds - multiple board specific calls need to build at the same
time - so ARC common code can't use the API approach, it needs a
callback based design where each board registers it's specific set of
functions, and at runtime, depending on board detection, the callbacks
are used from the registry.

This commit adds all the infrastructure, where board specific callbacks
are specified as a "maThine description".

All the hooks are placed in right spots, no board callbacks registered
yet (with MACHINE_STARt/END constructs) so the hooks will not run.

Next commit will actually convert the platform to this infrastructure.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:13 +05:30
Vineet Gupta cbe056f76a ARC: Hostlink Pseudo-Driver for Metaware Debugger
This allows ARC Target to do I/O to host in absence of any peripherals
whatsoever, assisted by Metaware Hostlink facility.

Further we have a FUSE based filesystem which makes us mount/access host
filesystem on target and do fops.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:10 +05:30
Vineet Gupta 8b5850f8ac ARC: Support for single cycle Close Coupled Mem (CCM)
* Includes mapping of CCMs in address space
* Annotations to move arbitrary code/data into CCM
* Moving some of the critical code/data into CCM
* Runtime detection/reporting

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:10 +05:30
Vineet Gupta af61742813 ARC: Boot #2: Verbose Boot reporting / feature verification
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:07 +05:30
Mischa Jonker f46121bd26 ARC: kgdb support
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
2013-02-15 23:16:07 +05:30
Vineet Gupta 2e651ea159 ARC: Unaligned access emulation
ARC700 doesn't natively support unaligned access, but can be emulated
-Unaligned Access Exception
-Disassembly at the Fault address to find the exact insn (long/short)

Also per Arnd's comment, we runtime control it using 2 sysctl knobs:
* SYSCTL_ARCH_UNALIGN_ALLOW: Runtime enable/disble
* SYSCTL_ARCH_UNALIGN_NO_WARN: Warn on each emulation attempt

Originally contributed by Tim Yao <tim.yao@amlogic.com>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Tim Yao <tim.yao@amlogic.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:06 +05:30
Vineet Gupta 4d86dfbbda ARC: kprobes support
Origin port done by Rajeshwar Ranga

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
2013-02-15 23:16:05 +05:30
Vineet Gupta e65ab5a875 ARC: disassembly (needed by kprobes/kgdb/unaligned-access-emul)
In-kernel disassembler

Due Credits
* Orig written by Rajeshwar Ranga
* Consolidation/cleanups by Mischa Jonker

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
Cc: Mischa Jonker <mjonker@synopsys.com>
2013-02-15 23:16:04 +05:30
Vineet Gupta 44c8bb9140 ARC: stacktracing APIs based on dw2 unwinder
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:04 +05:30
Vineet Gupta 854a0d9505 ARC: DWARF2 .debug_frame based stack unwinder
-Originally written by Rajeshwar Ranga
-Derived off of generic unwinder in 2.6.19 and adapted to ARC

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
2013-02-15 23:16:03 +05:30
Vineet Gupta 41195d236e ARC: SMP support
ARC common code to enable a SMP system + ISS provided SMP extensions.

ARC700 natively lacks SMP support, hence some of the core features are
are only enabled if SoCs have the necessary h/w pixie-dust. This
includes:
-Inter Processor Interrupts (IPI)
-Cache coherency
-load-locked/store-conditional
...

The low level exception handling would be completely broken in SMP
because we don't have hardware assisted stack switching. Thus a fair bit
of this code is repurposing the MMU_SCRATCH reg for event handler
prologues to keep them re-entrant.

Many thanks to Rajeshwar Ranga for his initial "major" contributions to
SMP Port (back in 2008), and to Noam Camus and Gilad Ben-Yossef for help
with resurrecting that in 3.2 kernel (2012).

Note that this platform code is again singleton design pattern - so
multiple SMP platforms won't build at the moment - this deficiency is
addressed in subsequent patches within this series.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rajeshwar Ranga <rajeshwar.ranga@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
2013-02-15 23:16:02 +05:30
Vineet Gupta 0ef88a54aa ARC: Diagnostics: show_regs() etc
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:02 +05:30
Vineet Gupta fa1c3ff935 ARC: Module support
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:01 +05:30
Vineet Gupta 4788a5942b ARC: Support for high priority interrupts in the in-core intc
There is a bit of hack/kludge right now where we disable preemption if a
L2 (High prio) IRQ is taken while L1 (Low prio) is active.

Need to revisit this

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:01 +05:30
Vineet Gupta 547f112571 ARC: ptrace support
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:15:59 +05:30
Vineet Gupta 080c37473e ARC: [optim] Cache "current" in Register r25
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:58 +05:30
Vineet Gupta c08098f28e ARC: Last bits (stubs) to get to a running kernel with UART
This was part of port buildup strategy from Arnd to have a minimal kernel
at first and then add optional features (stacktracing, ptrace, smp,
kprobes, oprofile....)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:57 +05:30
Vineet Gupta abe11ddea1 ARC: [plat-arcfpga]: Enabling DeviceTree for Angel4 board
* arc-uart platform device now populated dynamically, using
  of_platform_populate() - applies to any other device whatsoever.

* uart in turn requires incore arc-intc to be also present in DT

* A irq-domain needs to be instantiated for IRQ requests by DT probed
  device (e.g. arc-uart)

TODO: switch over to linear irq domain once all devs have been
      transitioned to DT

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:15:57 +05:30
Vineet Gupta 450dd430bf ARC: [DeviceTree] Convert some Kconfig items to runtime values
* mem size now runtime configured (prev CONFIG_ARC_PLAT_SDRAM_SIZE)
* core cpu clk runtime configured (prev CONFIG_ARC_PLAT_CLK)

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
2013-02-15 23:15:56 +05:30
Vineet Gupta 999159a538 ARC: [DeviceTree] Basic support
This is minimal infrastructure needed for devicetree work.
It uses an a sample "skeleton" devicetree - embedded in kernel image -
to print the board, manufacturer by parsing the top-level "compatible"
string.

As of now we don't need any additional "board" specific "machine_desc".

TODO: support interpreting the command line as boot-loader passed dtb

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
2013-02-15 23:15:55 +05:30
Vineet Gupta c121c5063c ARC: Boot #1: low-level, setup_arch(), /proc/cpuinfo, mem init
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:15:54 +05:30
Vineet Gupta 55bb9480f9 ARC: [Review] Prevent incorrect syscall restarts
Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366
there are 3 golden rules for (not) restarting syscalls:

"	What we need to guarantee is
* restarts do not happen on signals caught in interrupts or exceptions
* restarts do not happen on signals caught in sigreturn()
* restart should happen only once, even if we get through do_signal()
  many times."

ARC Port already handled #1, this patch fixes #2 and #3.

We use the additional state in pt_regs->orig_r8 to ckh if restarting
has already been done once.

Thanks to Al Viro for spotting this.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
2013-02-15 23:15:50 +05:30
Vineet Gupta 5c39c0ab5e ARC: [Review] Preparing to fix incorrect syscall restarts due to signals
To avoid multiple syscall restarts (multiple signals) or no restart at
all (sigreturn), we need just an extra bit of state "literally 1 bit" in
struct pt_regs. orig_r8 is the best place to do this, however given the
way it is encoded currently, we can't add anything simplistically.

Current orig_r8:
* syscalls   -> 1 to NR_SYSCALLS
* Exceptions -> NR_SYSCALLS + 1
* Break-point-> NR_SYSCALLS + 2

In new scheme it is a bit-field
* lower short word contains the  exact event type (and a new bit to represent
   restart semantics : if syscall was already / can't be restarted)
* upper short word optionally containing the syscall num - needed by
  likes of tracehooks etc

This patch only changes how orig_r8 is organised and nothing should
change behaviourily.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
2013-02-15 23:15:49 +05:30
Vineet Gupta c3581039b6 ARC: Signal handling
Includes following fixes courtesy review by Al-Viro

* Tracer poke to Callee-regs were lost

  Before going off into do_signal( ) we save the user-mode callee regs
  (as they are not saved by default as part of pt_regs). This is to make
  sure that that a Tracer (if tracing related signal) is able to do likes
  of PEEKUSR(callee-reg).

  However in return path we were simply discarding the user-mode callee
  regs, which would break a POKEUSR(callee-reg) from a tracer.

* Issue related to multiple syscall restarts are addressed in next patch

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Jonas Bonn <jonas@southpole.se>
2013-02-15 23:03:30 +05:30
Vineet Gupta d8005e6b95 ARC: Timers/counters/delay management
ARC700 includes 2 in-core 32bit timers TIMER0 and TIMER1.
Both have exactly same capabilies.

* programmable to count from TIMER<n>_CNT to TIMER<n>_LIMIT
* for count 0 and LIMIT ~1, provides a free-running counter by
    auto-wrapping when limit is reached.
* optionally interrupt when LIMIT is reached (oneshot event semantics)
* rearming the interrupt provides periodic semantics
* run at CPU clk

ARC Linux uses TIMER0 for clockevent (periodic/oneshot) and TIMER1 for
clocksource (free-running clock).

Newer cores provide RTSC insn which gives a 64bit cpu clk snapshot hence
is more apt for clocksource when available.

SMP poses a bit of challenge for global timekeeping clocksource /
sched_clock() backend:
 -TIMER1 based local clocks are out-of-sync hence can't be used
  (thus we default to jiffies based cs as well as sched_clock() one/both
  of which platform can override with it's specific hardware assist)
 -RTSC is only allowed in SMP if it's cross-core-sync (Kconfig glue
  ensures that) and thus usable for both requirements.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-02-11 20:00:39 +05:30
Vineet Gupta bf90e1eab6 ARC: Process-creation/scheduling/idle-loop
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-02-11 20:00:38 +05:30
Vineet Gupta 4adeefe161 ARC: Syscall support (no-legacy-syscall ABI)
This includes support for generic clone/for/vfork/execve

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11 20:00:38 +05:30
Vineet Gupta 054419ed84 ARC: Non-MMU Exception Handling
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-11 20:00:37 +05:30
Vineet Gupta bacdf4809a ARC: Interrupt Handling
This contains:
-bootup arch IRQ init: init_IRQ(), arc_init_IRQ()
-generic IRQ subsystem glue: arch_do_IRQ()
-basic IRQ chip setup for in-core intc

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-02-11 20:00:37 +05:30
Vineet Gupta 9d42c84f91 ARC: Low level IRQ/Trap/Exception Handling
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
2013-02-11 20:00:36 +05:30
Vineet Gupta ac4c244d4e ARC: irqflags - Interrupt enabling/disabling at in-core intc
ARC700 has an in-core intc which provides 2 priorities (a.k.a.) "levels"
of interrupts (per IRQ) hencforth referred to as L1/L2 interrupts.

CPU flags register STATUS32 has Interrupt Enable bits per level (E1/E2)
to globally enable (or disable) all IRQs at a level. Hence the
implementation of arch_local_irq_{save,restore,enable,disable}( )

The STATUS32 reg can be r/w only using the AUX Interface of ARC, hence
the use of LR/SR instructions. Further, E1/E2 bits in there can only be
updated using the FLAG insn.

The intc supports 32 interrupts - and per IRQ enabling is controlled by
a bit in the AUX_IENABLE register, hence the implmentation of
arch_{,un}mask_irq( ) routines.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
2013-02-11 20:00:30 +05:30
Vineet Gupta cfdbc2e16e ARC: Build system: Makefiles, Kconfig, Linker script
Arnd in his review pointed out that arch Kconfig organisation has several
deficiencies:

* Build time entries for things which can be runtime extracted from DT
  (e.g. SDRAM size, core clk frequency..)
* Not multi-platform-image-build friendly (choice .. endchoice constructs)
* cpu variants support (750/770) is exclusive.

The first 2 have been fixed in subsequent patches.
Due to the nature of the 750 and 770, it is not possible to build for
both together, w/o special runtime glue code which would hurt
performance.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
2013-02-11 20:00:25 +05:30