Commit Graph

1411 Commits

Author SHA1 Message Date
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 bed30976e7 ARC: pt_regs update #0: remove kernel stack canary
This stack slot is going to be used in subsequent commits

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 3abc944802 ARC: [mm] Make stack/heap Non-executable by default
1. For VM_EXEC based delayed dcache/icache flush, reduces the number of
   flushes.

2. Makes this security feature ON by default rather than OFF before.

3. Applications can use mprotect() to selectively override this.

4. ELF binaries have a GNU_STACK segment which can easily override the
   kernel default permissions.
   For nested-functions/trampolines, gcc already auto-enables executable
   stack in elf. Others needing this can use -Wl,-z,execstack option.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:20 +05:30
Vineet Gupta 2ed21dae02 ARC: [mm] Assume pagecache page dirty by default
Similar to ARM/SH

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:19 +05:30
Vineet Gupta fedf5b9baf ARC: [mm] optimise VIPT dcache aliasing 2/x
Non-congruent SRC page in copy_user_page() is dcache clean in the end -
so record that fact, to avoid a subsequent extraneous flush.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:19 +05:30
Vineet Gupta 5971bc719d ARC: [mm] optimise VIPT dcache aliasing 1/x
flush_cache_page() - kills icache only if page is executable

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:18 +05:30
Vineet Gupta 29b93c68bf ARC: [mm] Zero page optimization
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:18 +05:30
Alexey Brodkin 2f9e99618f ARC: make dcache VIPT aliasing support dependant on dcache
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:23:17 +05:30
Vineet Gupta 336e199e9c ARC: No-op full icache flush if !CONFIG_ARC_HAS_ICACHE
Also remove extraneous irq disabling in flush_cache_all() callstack

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 19:22:42 +05:30
Vineet Gupta 3049918660 ARC: cache detection code bitrot
* Number of (i|d)cache ways can be retrieved from BCRs and hence no need
  to cross check with with built-in constants
* Use of IS_ENABLED() to check for a Kconfig option
* is_not_cache_aligned() not used anymore

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:43 +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
Mischa Jonker ba5afadb11 ARC: [plat-arcfpga] Fix build breakage when !CONFIG_ARC_SERIAL
This fixes the following:
- CONFIG_ARC_SERIAL_BAUD is only defined when CONFIG_SERIAL_ARC is defined.
  Make sure that it isn't referenced otherwise.
- There is no use for initializing arc_uart_info[] when CONFIG_SERIAL_ARC is
  not defined.

[vgupta: tweaked changelog title, used IS_ENABLED() kconfig helper]
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-22 13:46:41 +05:30
Vineet Gupta 7bb66f6e6e ARC: lazy dcache flush broke gdb in non-aliasing configs
gdbserver inserting a breakpoint ends up calling copy_user_page() for a
code page. The generic version of which (non-aliasing config) didn't set
the PG_arch_1 bit hence update_mmu_cache() didn't sync dcache/icache for
corresponding dynamic loader code page - causing garbade to be executed.

So now aliasing versions of copy_user_highpage()/clear_page() are made
default. There is no significant overhead since all of special alias
handling code is compiled out for non-aliasing build

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-25 14:15:55 +05:30
Vineet Gupta 006dfb3c9c ARC: Use enough bits for determining page's cache color
The current code uses 2 bits for determining page's dcache color, thus
sorting pages into 4 bins, whereas the aliasing dcache really has 2 bins
(8k page, 64k dcache - 4 way-set-assoc).
This can cause extraneous flushes - e.g. color 0 and 2.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 14:25:09 +05:30
Vineet Gupta 3e87974dec ARC: Brown paper bag bug in macro for checking cache color
The VM_EXEC check in update_mmu_cache() was getting optimized away
because of a stupid error in definition of macro addr_not_cache_congruent()

The intention was to have the equivalent of following:

	if (a || (1 ? b : 0))

but we ended up with following:

	if (a || 1 ? b : 0)

And because precedence of '||' is more that that of '?', gcc was optimizing
away evaluation of <a>

Nasty Repercussions:
1. For non-aliasing configs it would mean some extraneous dcache flushes
   for non-code pages if U/K mappings were not congruent.
2. For aliasing config, some needed dcache flush for code pages might
   be missed if U/K mappings were congruent.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 14:24:52 +05:30
Vineet Gupta a950549c67 ARC: copy_(to|from)_user() to honor usermode-access permissions
This manifested as grep failing psuedo-randomly:

-------------->8---------------------
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$ ip address show lo | grep inet
[ARCLinux]$
[ARCLinux]$ ip address show lo | grep inet
    inet 127.0.0.1/8 scope host lo
-------------->8---------------------

ARC700 MMU provides fully orthogonal permission bits per page:
Ur, Uw, Ux, Kr, Kw, Kx

The user mode page permission templates used to have all Kernel mode
access bits enabled.
This caused a tricky race condition observed with uClibc buffered file
read and UNIX pipes.

1. Read access to an anon mapped page in libc .bss: write-protected
   zero_page mapped: TLB Entry installed with Ur + K[rwx]

2. grep calls libc:getc() -> buffered read layer calls read(2) with the
   internal read buffer in same .bss page.
   The read() call is on STDIN which has been redirected to a pipe.
   read(2) => sys_read() => pipe_read() => copy_to_user()

3. Since page has Kernel-write permission (despite being user-mode
   write-protected), copy_to_user() suceeds w/o taking a MMU TLB-Miss
   Exception (page-fault for ARC). core-MM is unaware that kernel
   erroneously wrote to the reserved read-only zero-page (BUG #1)

4. Control returns to userspace which now does a write to same .bss page
   Since Linux MM is not aware that page has been modified by kernel, it
   simply reassigns a new writable zero-init page to mapping, loosing the
   prior write by kernel - effectively zero'ing out the libc read buffer
   under the hood - hence grep doesn't see right data (BUG #2)

The fix is to make all kernel-mode access permissions mirror the
user-mode ones. Note that the kernel still has full access to pages,
when accessed directly (w/o MMU) - this fix ensures that kernel-mode
access in copy_to_from() path uses the same faulting access model as for
pure user accesses to keep MM fully aware of page state.

The issue is peudo-random because it only shows up if the TLB entry
installed in #1 is present at the time of #3. If it is evicted out, due
to TLB pressure or some-such, then copy_to_user() does take a TLB Miss
Exception, with a routine write-to-anon COW processing installing a
fresh page for kernel writes and also usable as it is in userspace.

Further the issue was dormant for so long as it depends on where the
libc internal read buffer (in .bss) is mapped at runtime.
If it happens to reside in file-backed data mapping of libc (in the
page-aligned slack space trailing the file backed data), loader zero
padding the slack space, does the early cow page replacement, setting
things up at the very beginning itself.

With gcc 4.8 based builds, the libc buffer got pushed out to a real
anon mapping which triggers the issue.

Reported-by: Anton Kolesov <akolesov@synopsys.com>
Cc: <stable@vger.kernel.org> # 3.9
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 10:33:03 +05:30
Vineet Gupta f538881cc6 ARC: [mm] Prevent stray dcache lines after__sync_icache_dcach()
Flush and INVALIDATE the dcache page.

This helper is only used for writeback of CODE pages to memory. So
there's no value in keeping the dcache lines around. Infact it is risky
as a writeback on natural eviction under pressure can cause un-needed
writeback with weird issues on aliasing dcache configurations.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-23 10:26:33 +05:30
Christian Ruppert 7d19273cd0 ARC: [TB10x] Remove redundant abilis,simple-pinctrl mechanism
The TB10x platform port includes a custom mechanism using to set up
default pin controller configurations using abilis,simple-default
pin configurations of nodes compatible with abilis,simple-pinctrl. This
mechanism is redundant with the Linux standard "default" pin
configuration, see commit ab78029ecc
"drivers/pinctrl: grab default handles from device core".
This patch removes the TB10x custom mechanism in favour of the Linux
standard.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-15 10:12:03 +05:30
Linus Torvalds 6019958d14 Aliasing VIPT dcache support for ARC
I'm satisified with testing, specially with fuse which has historically given
 grief to VIPT arches (ARM/PARISC...)
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Merge tag 'arc-v3.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull second set of arc arch updates from Vineet Gupta:
 "Aliasing VIPT dcache support for ARC

  I'm satisified with testing, specially with fuse which has
  historically given grief to VIPT arches (ARM/PARISC...)"

* tag 'arc-v3.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: [TB10x] Remove GENERIC_GPIO
  ARC: [mm] Aliasing VIPT dcache support 4/4
  ARC: [mm] Aliasing VIPT dcache support 3/4
  ARC: [mm] Aliasing VIPT dcache support 2/4
  ARC: [mm] Aliasing VIPT dcache support 1/4
  ARC: [mm] refactor the core (i|d)cache line ops loops
  ARC: [mm] serious bug in vaddr based icache flush
2013-05-10 07:24:14 -07:00
Vineet Gupta e7d5bab5ef ARC: [TB10x] Remove GENERIC_GPIO
This tracks Alexandre Courbot's mainline GPIO rework

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
2013-05-10 09:50:33 +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
Vineet Gupta 5bba49f539 ARC: [mm] Aliasing VIPT dcache support 4/4
Enforce congruency of userspace shared mappings

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 22:00:57 +05:30
Vineet Gupta de2a852cc0 ARC: [mm] Aliasing VIPT dcache support 3/4
Fix the one zillion warnings

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 22:00:57 +05:30
Vineet Gupta 4102b53392 ARC: [mm] Aliasing VIPT dcache support 2/4
This is the meat of the series which prevents any dcache alias creation
by always keeping the U and K mapping of a page congruent.
If a mapping already exists, and other tries to access the page, prev
one is flushed to physical page (wback+inv)

Essentially flush_dcache_page()/copy_user_highpage() create K-mapping
of a page, but try to defer flushing, unless U-mapping exist.
When page is actually mapped to userspace, update_mmu_cache() flushes
the K-mapping (in certain cases this can be optimised out)

Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page()
handle the puring of stale userspace mappings on exit/munmap...

flush_anon_page() handles the existing U-mapping for anon page before
kernel reads it via the GUP path.

Note that while not complete, this is enough to boot a simple
dynamically linked Busybox based rootfs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 21:59:46 +05:30
Vineet Gupta 6ec18a81b2 ARC: [mm] Aliasing VIPT dcache support 1/4
This preps the low level dcache flush helpers to take vaddr argument in
addition to the existing paddr to properly flush the VIPT dcache

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 21:53:16 +05:30
Vineet Gupta a690984d60 ARC: [mm] refactor the core (i|d)cache line ops loops
Nothing semantical
* simplify the alignement code by using & operation only
* rename variables clearly as paddr

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 14:18:50 +05:30
Vineet Gupta c917a36f5f ARC: [mm] serious bug in vaddr based icache flush
vaddr used to index the cache was clipped from the wrong end, and thus
would potentially fail to flush the correct lines.

The problem was dorment for so long because up until the recent
optimizations it was only used for ptrace break-point only flushes.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-09 13:45:12 +05:30
Vineet Gupta eacd0e950d ARC: [mm] Lazy D-cache flush (non aliasing VIPT)
flush_dcache_page( ) is MM hook to ensure that a page has consistent
views between kernel and userspace. Thus it is called when

* kernel writes to a page which at some later point could get mapped to
  userspace (so kernel mapping needs to be flushed-n-inv)
* kernel is about to read from a page with possible userspace mappings
  (so userspace mappings needs to be made coherent with kernel ones)

However for Non aliasing VIPT dcache, any userspace mapping will always
be congruent to kernel mapping. Thus d-cache need need not be flushed at
all (or delayed indefinitely).

The only reason it does need to be flushed is when mapping code pages.
Since icache doesn't snoop dcache, those dirty dcache lines need to be
written back to memory and icache line invalidated so that icache lines
fetch will get the right data.

Decent gains on LMBench fork/exec/sh and File I/O micro-benchmarks.

(1) FPGA @ 80 MHZ

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
3.9-rc6-a Linux 3.9.0-r   80 4.79 8.72 66.7 116. 239. 8.39 30.4 4798 14.K 34.K
3.9-rc6-b Linux 3.9.0-r   80 4.79 8.62 65.4 111. 239. 8.35 29.0 3995 12.K 30.K
3.9-rc7-c Linux 3.9.0-r   80 4.79 9.00 66.1 106. 239. 8.61 30.4 2858 10.K 24.K
                                                                ^^^^ ^^^^ ^^^

File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host                 OS   0K File      10K File     Mmap    Prot   Page 100fd
                        Create Delete Create Delete Latency Fault  Fault selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
3.9-rc6-a Linux 3.9.0-r  317.8  204.2 1122.3  375.1 3522.0 4.288     20.7 126.8
3.9-rc6-b Linux 3.9.0-r  298.7  223.0 1141.6  367.8 3531.0 4.866     20.9 126.4
3.9-rc7-c Linux 3.9.0-r  278.4  179.2  862.1  339.3 3705.0 3.223     20.3 126.6
                         ^^^^^  ^^^^^  ^^^^^  ^^^^

(2) Customer Silicon @ 500 MHz (166 MHz mem)

------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
abilis-ba Linux 3.9.0-r  497 0.71 1.38 4.58 12.0 35.5 1.40 3.89 2070 5525 13.K
abilis-ca Linux 3.9.0-r  497 0.71 1.40 4.61 11.8 35.6 1.37 3.92 1411 4317 10.K
                                                                ^^^^ ^^^^ ^^^

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:15 +05:30
Vineet Gupta 764531cc5a ARC: [mm] micro-optimize page size icache invalidate
start address is already page aligned and size is const PAGE_SIZE,
thus fixups for alignment not needed in generated code.

bloat-o-meter vmlinux-mm5 vmlinux
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-32 (-32)
function                                     old     new   delta
__inv_icache_page                             82      50     -32

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:14 +05:30
Vineet Gupta 7f250a0fa1 ARC: [mm] remove the pessimistic all-alias-invalidate icache helpers
No users of this code anymore - so RIP !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:13 +05:30
Vineet Gupta 94bad1afee ARC: [mm] consolidate icache/dcache sync code
Now that we have same helper used for all icache invalidates (i.e.
vaddr+paddr based exact line invalidate), consolidate the open coded
calls into one place.

Also rename flush_icache_range_vaddr => __sync_icache_dcache

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:13 +05:30
Vineet Gupta 7586bf7286 ARC: [mm] optimise icache flush for kernel mappings
This change continues the theme from prev commit - this time icache
handling for kernel's own code modification (vmalloc: loadable modules,
breakpoints for kprobes/kgdb...)

flush_icache_range() calls the CDU icache helper with vaddr to enable
exact line invalidate.

For a true kernel-virtual mapping, the vaddr is actually virtual hence
valid as index into cache. For kprobes breakpoint however, the vaddr arg
is actually paddr - since that's how normal kernel is mapped in ARC
memory map.  This implies that CDU will use the same addr for
indexing as for tag match - which is fine since kernel code would only
have that "implicit" mapping and none other.

This should speed up module loading significantly - specially on default
ARC700 icache configurations (32k) which alias.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:12 +05:30
Vineet Gupta 24603fdd19 ARC: [mm] optimise icache flush for user mappings
ARC icache doesn't snoop dcache thus executable pages need to be made
coherent before mapping into userspace in flush_icache_page().

However ARC700 CDU (hardware cache flush module) requires both vaddr
(index in cache) as well as paddr (tag match) to correctly identify a
line in the VIPT cache. A typical ARC700 SoC has aliasing icache, thus
the paddr only based flush_icache_page() API couldn't be implemented
efficiently. It had to loop thru all possible alias indexes and perform
the invalidate operation (ofcourse the cache op would only succeed at
the index(es) where tag matches - typically only 1, but the cost of
visiting all the cache-bins needs to paid nevertheless).

Turns out however that the vaddr (along with paddr) is available in
update_mmu_cache() hence better suits ARC icache flush semantics.
With both vaddr+paddr, exactly one flush operation per line is done.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 19:08:12 +05:30
Vineet Gupta 8d56bec2f2 ARC: [mm] optimize needless full mm TLB flush on munmap
munmap ends up calling tlb_flush() which for ARC was flushing the entire
TLB unconditionally (by moving the MMU to a new ASID)

do_munmap
  unmap_region
    unmap_vmas
      unmap_single_vma
         unmap_page_range
            tlb_start_vma
            zap_pud_range
            tlb_end_vma()
  tlb_finish_mmu
    tlb_flush()  ---> unconditional flush_tlb_mm()

So even a single page munmap, a frequent operation when uClibc dynamic
linker (ldso) is loading the dependent shared libraries, would move the
the ASID multiple times - needlessly invalidating the pre-faulted TLB
entries (and increasing the rate of ASID wraparound + full TLB flush).

This is now optimised to only be called if tlb->full_mm (which means
for exit/execve) cases only. And for those cases, flush_tlb_mm() is
already optimised to be a no-op for mm->mm_users == 0.

So essentially there are no mmore full mm flushes - except for fork which
anyhow needs it for properly COW'ing parent address space.

munmap now needs to do TLB range flush, which is implemented with
tlb_end_vma()

Results
-------
1. ASID now consistenly moves by 4 during a simple ls (as opposed to 5 or
   7 before).

2. LMBench microbenchmark also shows improvements

Basic system parameters
------------------------------------------------------------------------------
Host                 OS Description              Mhz  tlb  cache  mem scal
                                                     pages line   par load
                                                           bytes
--------- ------------- ----------------------- ---- ----- ----- ------ ----
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0404-gcc-4.4-ba   80     8    64 1.1000 1
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0405-avoid-full   80     8    64 1.1200 1

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
3.9-rc5-0 Linux 3.9.0-r   80 4.81 8.69 68.6 118. 239. 8.53 31.6 4839 13.K 34.K
3.9-rc5-0 Linux 3.9.0-r   80 4.46 8.36 53.8 91.3 223. 8.12 24.2 4725 13.K 33.K

File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host                 OS   0K File      10K File     Mmap    Prot   Page 100fd
                        Create Delete Create Delete Latency Fault  Fault selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
3.9-rc5-0 Linux 3.9.0-r  314.7  223.2 1054.9  390.2  3615.0 1.590 20.1 126.6
3.9-rc5-0 Linux 3.9.0-r  265.8  183.8 1014.2  314.1  3193.0 6.910 18.8 110.4

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:44:00 +05:30
Mischa Jonker a92a5d0dce ARC: Add support for nSIM OSCI System C model
This adds support for an ARC Virtual Platform. This platform is based on the
System C standard promoted by the OSCI (Open System C Initiative) and uses
nSIM to simulate the ARC CPU core itself.

Users can build a virtual SoC by combining System C models of peripherals
and CPU cores.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:44:00 +05:30
Christian Ruppert 0dfad77d0a ARC: [TB10x] Adapt device tree to new compatible string
The original device tree was written using a slightly different
implementation of the fixed-factor-clock device tree binding. The
compatible string must be modified in order to be compatible with the
new implementation.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:59 +05:30
Christian Ruppert 072eb69390 ARC: [TB10x] Add support for TB10x platform
Infrastructure required to make the Linux kernel compile and boot on the
Abilis Systems TB10x series of SOCs based on ARC700 CPUs:
  - Kmake related files (Kconfig, Makefile, tb10x_defconfig)
  - TB10x platform initialisation

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 13:43:59 +05:30
Christian Ruppert 2eb9504bcc ARC: [TB10x] Device tree of TB100 and TB101 Development Kits
These are the device tree files for the Abilis Systems TB100 and TB101 ICs and
their respective development kit PCBs. These files are committed in preparation
of the following patch set which adds support for these chips to the ARC
platform.

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
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 330db3330a ARC: [plat-arcfpga] defconfig update
* Allow initramfs path to be symlink
* CONFIG_PREEMPT be default

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
Noam Camus e3edeb67fb ARC: Respect the cpu_id passed for fetching correct cpu info
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:54 +05:30
Alexander Shiyan 0e82284514 ARC: Remove non existent refs to GENERIC_KERNEL_EXECVE & GENERIC_KERNEL_THREAD
This tracks mainline commit ae903caae2 "Bury the conditionals from
kernel_thread/kernel_execve series" which we missed out as ARC port was
not yet mainline.

[vgupta: commit log modified]

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-05-07 13:43:53 +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
Linus Torvalds 8700c95adb Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP/hotplug changes from Ingo Molnar:
 "This is a pretty large, multi-arch series unifying and generalizing
  the various disjunct pieces of idle routines that architectures have
  historically copied from each other and have grown in random, wildly
  inconsistent and sometimes buggy directions:

   101 files changed, 455 insertions(+), 1328 deletions(-)

  this went through a number of review and test iterations before it was
  committed, it was tested on various architectures, was exposed to
  linux-next for quite some time - nevertheless it might cause problems
  on architectures that don't read the mailing lists and don't regularly
  test linux-next.

  This cat herding excercise was motivated by the -rt kernel, and was
  brought to you by Thomas "the Whip" Gleixner."

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  idle: Remove GENERIC_IDLE_LOOP config switch
  um: Use generic idle loop
  ia64: Make sure interrupts enabled when we "safe_halt()"
  sparc: Use generic idle loop
  idle: Remove unused ARCH_HAS_DEFAULT_IDLE
  bfin: Fix typo in arch_cpu_idle()
  xtensa: Use generic idle loop
  x86: Use generic idle loop
  unicore: Use generic idle loop
  tile: Use generic idle loop
  tile: Enter idle with preemption disabled
  sh: Use generic idle loop
  score: Use generic idle loop
  s390: Use generic idle loop
  powerpc: Use generic idle loop
  parisc: Use generic idle loop
  openrisc: Use generic idle loop
  mn10300: Use generic idle loop
  mips: Use generic idle loop
  microblaze: Use generic idle loop
  ...
2013-04-30 07:50:17 -07:00
Jiang Liu d2309a1996 mm/arc: use common help functions to free reserved pages
Use common help functions to free reserved pages.

Signed-off-by: Jiang Liu <jiang.liu@huawei.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>
2013-04-29 15:54:31 -07:00
Vineet Gupta a89516b31c ARC: [kbuild] Avoid DTB rebuilds if DTS are untouched
Currently, for every ARC kernel build I see the following:

--------------->8-----------------
  DTB    arch/arc/boot/dts/angel4.dtb.S
  AS      arch/arc/boot/dts/angel4.dtb.o
  LD      arch/arc/boot/dts/built-in.o
rm arch/arc/boot/dts/angel4.dtb.S        <-- forces rebuild next iter
  CHK     kernel/config_data.h
--------------->8-----------------

This is because *.dts.S is intermediate file in dtb generation and is by
default deleted by make which needs a ".SECONDARY" hint to NOT do so.

This could have ideally been done in scripts/Makefile.lib - for benefit
of all, however .SECONDARY doesn't seem to work with wildcards.

Thanks to Stephen for suggesting .SECONDARY (vs .PRECIOUS) and making
that work using a non wildcard version in arch makefile.

Thanks to James Hogan for pointing out that *.dtb.S now needs to be
added to clean-files

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-17 18:19:14 +05:30
Thomas Gleixner d190e8195b idle: Remove GENERIC_IDLE_LOOP config switch
All archs are converted over. Remove the config switch and the
fallback code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-17 10:39:38 +02:00
Vineet Gupta 5628832f4c ARC: [kbuild] Include Kconfig.binfmt
commit "fs: make binfmt support for #! scripts modular and removable"
made support for #!scripts optional - thus need to include the Kconfig
file to get all relevant BINFMT_*

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:27:01 +05:30
Vineet Gupta fbf8e13d31 ARC: [kbuild] Allow platforms to disable LLSC for !SMP as well
Currently ARC_HAS_LLSC can be influenced by platform for SMP only using
ARC_HAS_COH_LLSC. For !SMP it defaults to "y".

It turns out that some customers can't support it all, even in UP.
So we change the semantics, and use a negative dependency ARC_CANT_LLSC.
Any platform (independent of SMP or !SMP) can select it to disable LLSC.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 17:27:00 +05:30
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
Vineet Gupta 104058ede7 ARC: [build] Allow uncompressed uImage
The existing uImage target always generates gzip compressed image which
drags bootup for some very slow FPGA customer boards.

So introduce seperate make targets:uImage.{bin,gz} with uncompressed
being default. Also tie gz generation to CONFIG_KERNEL_GZIP, which a
platform can select in it's Kconfig if it wishes gz to be default.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Vineet Gupta fb0990bbf5 ARC: [build] cleanup Makefile a bit
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Vineet Gupta af4c3ae399 ARC: [build] silence make defconfig warnings with host gcc 4.7
We do cross compiles for ARC Linux.
With gcc 4.7, a make defconfig spews out the following:

------------------->8--------------------------
make ARCH=arc defconfig
gcc: error: unrecognized command line option '-marc600'
gcc: error: unrecognized command line option '-mA7'
gcc: error: unrecognized command line option '-mno-sdata'
gcc: error: unrecognized command line option '-mno-mpy'
*** Default configuration is based on 'fpga_defconfig'
------------------->8--------------------------

This apparently is coming from LIBGCC line - which is strange to be
invoked for defconfig generation.

Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +05:30
Paul Bolle 610c6502e0 ARC: remove #ifdef-ed out include of dead header
There's no (Kconfig) macro CONFIG_BLOCK_DEV_RAM. (CONFIG_BLK_DEV_RAM
does exist though.) But linux/blk.h got killed in 2005 anyway (in a
patch titled "kill blk.h"), so these three lines can be removed.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-04-09 12:21:15 +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
Sachin Kamat 39d0c30d00 ARC: Remove unneeded version.h header include
version.h header file inclusion is not necessary as detected by
versioncheck script.

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
Christian Ruppert 79e5f05edc ARC: Add implicit compiler barrier to raw_local_irq* functions
ARC irqsave/restore macros were missing the compiler barrier, causing a
stale load in irq-enabled region be used in irq-safe region, despite
being changed, because the register holding the value was still live.

The problem manifested as random crashes in timer code when stress
testing ARCLinux (3.9-rc3) on a !SMP && !PREEMPT_COUNT

Here's the exact sequence which caused this:
 (0). tv1[x] <----> t1 <---> t2
 (1). mod_timer(t1) interrupted after it calls timer_pending()
 (2). mod_timer(t2) completes
 (3). mod_timer(t1) resumes but messes up the list
 (4). __runt_timers( ) uses bogus timer_list entry / crashes in
      timer->function

Essentially mod_timer() was racing against itself and while the spinlock
serialized the tv1[] timer link list, timer_pending() called outside the
spinlock, cached timer link list element in a register.
With low register pressure (and a deep register file), lack of barrier
in raw_local_irqsave() as well as preempt_disable (!PREEMPT_COUNT
version), there was nothing to force gcc to reload across the spinlock,
causing a stale value in reg be used for link list manipulation - ensuing
a corruption.

ARcompact disassembly which shows the culprit generated code:

mod_timer:
    push_s blink
    mov_s r13,r0	# timer, timer
..
    ###### timer_pending( )
    ld_s r3,[r13]       # <------ <variable>.entry.next LOADED
    brne r3, 0, @.L163

.L163:
..
    ###### spin_lock_irq( )
    lr  r5, [status32]  # flags
    bic r4, r5, 6       # temp, flags,
    and.f 0, r5, 6      # flags,
    flag.nz r4

    ###### detach_if_pending( ) begins

    tst_s r3,r3  <--------------
			# timer_pending( ) checks timer->entry.next
                        # r3 is NOT reloaded by gcc, using stale value
    beq.d @.L169
    mov.eq r0,0

    #####  detach_timer( ): __list_del( )

    ld r4,[r13,4]    	# <variable>.entry.prev, D.31439
    st r4,[r3,4]     	# <variable>.prev, D.31439
    st r3,[r4]       	# <variable>.next, D.30246

We initially tried to fix this by adding barrier() to preempt_* macros
for !PREEMPT_COUNT but Linus clarified that it was anything but wrong.
http://www.spinics.net/lists/kernel/msg1512709.html

[vgupta: updated commitlog]

Reported-by/Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Debugged-by/Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-08 16:10:26 -07:00
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
Pierrick Hascoet 2105fd550c arc: fix dma_address assignment during dma_map_sg()
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-19 15:34:53 +05:30
Masanari Iida cf2fbdd26f treewide: Fix typos in printk and comment
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-03-18 14:57:53 +01:00
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 a37b2dc52b ARC: Remove SET_PERSONALITY (tracks cross-arch change)
Tracks commit e72837e3e7 "default SET_PERSONALITY() in linux/elf.h"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-03-18 14:37:05 +05:30
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 8ccfe6675f ARC: split elf.h into uapi and export it for userspace
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-27 20:00:26 +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 5dc99e50d2 ARC: gdbserver using regset interface possibly broken
ptrace regset interface relies on ELF_NGREG for ceiling the size of user
request. So any larger request (even if legit)  would be clipped.

The existing def of ELF_NGREG didn't use user_regs_struct and was
technically one placeholder short (stop_pc) - although the current code
would still work because pt_regs includes a bunch of extra fields,
making
      ELF_NGREG >= sizeof(struct user_regs_struct)/sizeof(long)

But we need to remove this ambiguity, specially since pt_regs should NOT
be directly associated with with anything userspace-ish.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-27 19:59:55 +05:30
Vineet Gupta 7e0d306c37 ARC: Kconfig cleanup tracking cross-arch Kconfig pruning in merge window
Since ARC port was not yet upstream, we missed a bunch of cross-arch
Kconfig removals:

* GENERIC_SIGALTSTACK: d64008a8f3 "burying unused conditionals"
* HAVE_IRQ_WORK: 6147a9d807 "irq_work: Remove CONFIG_HAVE_IRQ_WORK"
* ARCH_NO_VIRT_TO_BUS: e0cf2ef484 "arch Kconfig: centralise
                                   CONFIG_ARCH_NO_VIRT_TO_BUS"

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-26 14:25:22 +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 fc32781bfd ARC: [plat-arcfpga] DT arc-uart bindings change: "baud" => "current-speed"
Per Grant's review comment - driver changes via tty tree

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:22 +05:30
Vineet Gupta 70b319f2be ARC: Ensure CONFIG_VIRT_TO_BUS is not enabled
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Reported-by: James Hogan <james.hogan@imgtec.com>
2013-02-15 23:16:21 +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 d626f547dd ARC: Don't fiddle with non-existent caches
!CONFIG_ARC_HAS_(I|D)CACHE makes Linux disable caches (assuming they
exist in hardware) - mostly for debugging issues with new peripherals.
However, independent of CONFIG_ARC_HAS_(I|D)CACHE, Linux also needs to
handle, non-existant caches, using the information in Cache BCRs (Build
Configuration Reg)

Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:19 +05:30
Vineet Gupta 0208c96a9d ARC: Provide a default serial.h for uart drivers needing BASE_BAUD
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:18 +05:30
Vineet Gupta 95461a64e9 ARC: [plat-arcfpga] defconfig for fully loaded ARC Linux
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:17 +05:30
Vineet Gupta b830cde5a4 ARC: [Review] Multi-platform image #8: platform registers SMP callbacks
Platforms export their SMP callbacks by populating arc_smp_ops.
The population itself needs to be done pretty early, from init_early
callback.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:17 +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 fc7943d29e ARC: [Review] Multi-platform image #6: cpu-to-dma-addr optional
All the current platforms can work with 0x8000_0000 based dma_addr_t
since the Bus Bridges typically ignore the top bit (the only excpetion
was Angel4 PCI-AHB bridge which we no longer care for).
That way we don't need plat-specific cpu-addr to bus-addr conversion.

Hooks still provided - just in case a platform has an obscure device
which say needs 0 based bus address.

That way <asm/dma_mapping.h> no longer needs to unconditinally include
<plat/dma_addr.h>

Also verfied that on Angel4 board, other peripherals (IDE-disk / EMAC)
work fine with 0x8000_0000 based dma addresses.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:15 +05:30
Vineet Gupta decae9d3e8 ARC: [Review] Multi-platform image #5: NR_IRQS defined by ARC core
For now this will suffice for all platforms, later exotic ones needs to
get this from DeviceTree

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:15 +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 93ad700de2 ARC: Fold boards sub-menu into platform/SoC menu
This is more natural and is now doable since the choice constructs are
gone.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:13 +05:30
Vineet Gupta 53d98958f5 ARC: [Review] Multi-platform image #1: Kconfig enablement
This mini patchseries addresses the lack of multi-platform-image support
in ARC port.

Older build system only supported one platform(soc) to build at a time
and further only one board of that platform could be built. There was no
technical reason for that - we just didn't have the need.

So the first step towards multi-platform (and multi-board) builds it to
allow build system to do that.

So as applicable, <choice .. endchoice> => <menu .. endmenu>

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-15 23:16:12 +05:30
Gilad Ben-Yossef 4368902bb9 ARC: Add support for ioremap_prot API
Implement ioremap_prot() to allow mapping IO memory with variable
protection
via TLB.

Implementing this allows the /dev/mem driver to use its generic access()
VMA callback, which in turn allows ptrace to examine data in memory
mapped regions mapped via /dev/mem, such as Arc DCCM.

The end result is that it is possible to examine values of variables
placed into DCCM in user space programs via GDB.

CC: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
CC: Noam Camus <noamc@ezchip.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:11 +05:30
Vineet Gupta 8c2f4a8dd0 ARC: UAPI Disintegrate arch/arc/include/asm
1. ./genfilelist.pl arch/arc/include/asm/

2. Create arch/arc/include/uapi/asm/Kbuild as follows

	+# UAPI Header export list
	+include include/uapi/asm-generic/Kbuild.asm

3. ./disintegrate-one.pl arch/arc/include/{,uapi/}asm/<above-list>

4. Edit arch/arc/include/asm/Kbuild to remove ref to
	asm-generic/Kbuild.asm

- To work around empty uapi/asm/setup.h added a placholder comment.
- Also a manual #ifdef __ASSEMBLY__ for a late ptrace change

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: David Howells <dhowells@redhat.com>
2013-02-15 23:16:11 +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 9c57564e26 ARC: perf support (software counters only)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:09 +05:30
Vineet Gupta 7fadc1e8fe ARC: [plat-arfpga] BVCI Latency Unit setup
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:08 +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 769bc1fd7b ARC: OProfile support
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Robert Richter <rric@kernel.org>
Cc: oprofile-list@lists.sf.net
Reviewed-by: James Hogan <james.hogan@imgtec.com>
2013-02-15 23:16:00 +05:30
Vineet Gupta 01b812bcce ARC: Futex support
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:16:00 +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 8872e9e513 ARC: [plat-arcfpga] defconfig
With this we get to a running kernel on ISS

---------------------------------->8-----------------------------------
Linux version 3.8.0-rc3+ (vineetg@vineetg-Latitude) (gcc version 4.4.7
(ARCompact elf32 toolchain (built 20121213)) ) #3 Thu Jan 17 14:22:05
IST 2013
Board "arc-angel4" from snps (Manufacturer)
Memory size set via devicetree 256M
[plat-arcfpga]: registering early dev resources
bootconsole [early_ARCuart0] enabled
pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
pcpu-alloc: [0] 0
Built 1 zonelists in Zone order, mobility grouping on.  Total pages:
32624
Kernel command line: console=ttyARC0,115200n8
PID hash table entries: 1024 (order: -1, 4096 bytes)
Dentry cache hash table entries: 32768 (order: 4, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 3, 65536 bytes)
Memory Available: 248M / 256M (1312K code, 463K data, 4184K init, 1400K
reserv)
SLUB: Genslabs=12, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS:16
Console: colour dummy device 80x25
Calibrating delay loop... 39.73 BogoMIPS (lpj=198656)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024
devtmpfs: initialized
[plat-arcfpga]: registering device resources
bio: create slab <bio-0> at 0
Switching to clocksource ARC RTSC
io scheduler noop registered (default)
arc-uart: ttyARC0 at MMIO 0xc0fc1000 (irq = 5) is a arc-uart
console [ttyARC0] enabled, bootconsole disabled
console [ttyARC0] enabled, bootconsole disabled
mousedev: PS/2 mouse device common for all mice
Warning: unable to open an initial console.
Freeing unused kernel memory: 4184k [80002000] to [80418000]
Mounting proc
Mounting sysfs
Mounting devpts
Setting hostname to ARCLinux
Starting System logger (syslogd)
Bringing up loopback device
ifconfig: socket: Function not implemented
route: socket: Function not implemented
Disk not detected !
Mounting tmpfs
mount: mounting tmpfs on /dev/shm failed: Invalid argument
/etc/init.d/rcS: line 76: can't create /proc/sys/kernel/msgmni:
nonexistent directory

Please press Enter to activate this console.
***********************************************************************
                        Welcome to ARCLinux
***********************************************************************
[ARCLinux]$

---------------------------------->8-----------------------------------

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 ee36d17221 ARC: [plat-arcfpga] Static platform device for CONFIG_SERIAL_ARC
N.B. This is old style of hardcoding platform device specific info
in code and it's instantiation thererof using platform_add_devices().
Subsequent patches replace this with DeviceTree based runtime probe.

This patch has been retained just as an example of "don't-do-this" for
newer kernel ports.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
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 1162b0701b ARC: I/O and DMA Mappings
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:54 +05:30
Vineet Gupta fbd7053a78 ARC: Page Fault handling
This includes recent changes to make handler "retry" and/or "killable"

The killable (early exit) logic is loosely based on how SH implements it
	return if SIGKILL + either of VM_FAULT_OOM or VM_FAULT_RETRY
which is different from Hexagon implementation which would NOT early
exit for
	SIGKILL + VM_FAULT_OOM + !VM_FAULT_RETRY

credits: Non executable stack support from Simon Spooner

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:53 +05:30
Vineet Gupta d79e678d74 ARC: TLB flush Handling
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:53 +05:30
Vineet Gupta cc562d2eae ARC: MMU Exception Handling
* MMU I-TLB / D-TLB Miss Exceptions
  - Fast Path TLB Refill Handler
  - slowpath TLB creation via do_page_fault() -> update_mmu_cache()
* Duplicate PD Exception Handler

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:52 +05:30
Vineet Gupta f1f3347da9 ARC: MMU Context Management
ARC700 MMU provides for tagging TLB entries with a 8-bit ASID to avoid
having to flush the TLB every task switch.

It also allows for a quick way to invalidate all the TLB entries for
task useful for:
* COW sementics during fork()
* task exit()ing

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:51 +05:30
Vineet Gupta 5dda4dc570 ARC: Page Table Management
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:51 +05:30
Vineet Gupta 95d6976d20 ARC: Cache Flush Management
* ARC700 has VIPT L1 Caches
* Caches don't snoop and are not coherent
* Given the PAGE_SIZE and Cache associativity, we don't support aliasing
  D$ configurations (yet), but do allow aliasing I$ configs

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-15 23:15:50 +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 5210d1e688 ARC: String library
Hand optimised asm code for ARC700 pipeline.
Originally written/optimized by Joern Rennecke

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Joern Rennecke <joern.rennecke@embecosm.com>
2013-02-11 20:00:35 +05:30
Vineet Gupta 6e35fa2d43 ARC: Spinlock/rwlock/mutex primitives
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11 20:00:35 +05:30
Vineet Gupta 3be80aaef8 ARC: Fundamental ARCH data-types/defines
* L1_CACHE_SHIFT
* PAGE_SIZE, PAGE_OFFSET
* struct pt_regs, struct user_regs_struct
* struct thread_struct, cpu_relax(), task_pt_regs(), start_thread(), ...
* struct thread_info, THREAD_SIZE, INIT_THREAD_INFO(), TIF_*, ...
* BUG()
* ELF_*
* Elf_*

To disallow user-space visibility into some of the core kernel data-types
such as struct pt_regs, #ifdef __KERNEL__ which also makes the UAPI header
spit (further patch in the series) to NOT export it to asm/uapi/ptrace.h

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11 20:00:34 +05:30
Vineet Gupta ca15c8ecd5 ARC: Checksum/byteorder/swab routines
TBD: do_csum still needs to be written in asm

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11 20:00:34 +05:30
Vineet Gupta 0a5eae458e ARC: [optim] uaccess __{get,put}_user() optimised
Override asm-generic implementations. We basically gain on 2 fronts

* checks for alignment no longer needed as we are only doing "unit"
  sized copies.

  (Careful observer could argue that While the kernel buffers are aligned,
   the user buffer in theory might not be - however in that case the
   user space is already broken when it tries to deref a hword/word
   straddling word boundary - so we are not making it any worse).

* __copy_{to,from}_user( ) returns bytes that couldn't be copied,
  whereas get_user() returns 0 for success or -EFAULT (not size). Thus
  the code to do leftover bytes calculation can be avoided as well.

The savings were significant: ~17k of code.

bloat-o-meter vmlinux_uaccess_pre vmlinux_uaccess_post
add/remove: 0/4 grow/shrink: 8/118 up/down: 1262/-18758 (-17496)
							^^^^^^^^^
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2013-02-11 20:00:32 +05:30
Vineet Gupta 43697cb097 ARC: uaccess friends
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-11 20:00:31 +05:30
Vineet Gupta 14e968bad7 ARC: Atomic/bitops/cmpxchg/barriers
This covers the UP / SMP (with no hardware assist for atomic r-m-w) as
well as ARC700 LLOCK/SCOND insns based.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-02-11 20:00:30 +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
Vineet Gupta 79a033c6b9 ARC: Generic Headers
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-01-28 12:34:21 +05:30