Commit Graph

230 Commits

Author SHA1 Message Date
Palmer Dabbelt 7847e7052f
RISC-V: Define sys_riscv_flush_icache when SMP=n
This would be necessary to make non-SMP builds work, but there is
another error in the implementation of our syscall linkage that actually
just causes sys_riscv_flush_icache to never build.  I've build tested
this on allnoconfig and allnoconfig+SMP=y, as well as defconfig like
normal.

CC: Christoph Hellwig <hch@infradead.org>
CC: Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20180809055830.GA17533@infradead.org>
In-Reply-To: <20180809132612.GA31058@roeck-us.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-20 10:55:24 -07:00
Atish Patra 4c42ae4f6a
RISC-V: Fix !CONFIG_SMP compilation error
Enabling both CONFIG_PERF_EVENTS without !CONFIG_SMP
generates following compilation error.

arch/riscv/include/asm/perf_event.h:80:2: error: expected
specifier-qualifier-list before 'irqreturn_t'

  irqreturn_t (*handle_irq)(int irq_num, void *dev);
  ^~~~~~~~~~~

Include interrupt.h in proper place to avoid compilation
error.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:32 -07:00
Zong Li 94f592f0e5
RISC-V: Add the directive for alignment of stvec's value
The stvec's value must be 4 byte alignment by specification definition.
These directives avoid to stvec be set the non-alignment value.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Palmer Dabbelt 62b0194368
clocksource: new RISC-V SBI timer driver
The RISC-V ISA defines a per-hart real-time clock and timer, which is
present on all systems.  The clock is accessed via the 'rdtime'
pseudo-instruction (which reads a CSR), and the timer is set via an SBI
call.

Contains various improvements from Atish Patra <atish.patra@wdc.com>.

Signed-off-by: Dmitriy Cherkasov <dmitriy@oss-tech.org>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
[hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(),
 minor cleanups, merged  hotplug cpu support and other improvements
 from Atish]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Christoph Hellwig 6ea0f26a79
RISC-V: implement low-level interrupt handling
Add support for a routine that dispatches exceptions with the interrupt
flags set to either the IPI or irqdomain code (and the clock source in the
future).

Loosely based on the irq-riscv-int.c irqchip driver from the RISC-V tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:31 -07:00
Christoph Hellwig b9d5535746
RISC-V: simplify software interrupt / IPI code
Rename handle_ipi to riscv_software_interrupt, drop the unused return
value and move the prototype to irq.h together with riscv_timer_interupt.
This allows simplifying the upcoming interrupt handling support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:30 -07:00
Christoph Hellwig b9490350f7
RISC-V: remove timer leftovers
This code is currently unused and will be added back later in a different
place with the real interrupt and clocksource support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:30 -07:00
Palmer Dabbelt 5b5c2a2c44
RISC-V: Add early printk support via the SBI console
This code lives entirely within the RISC-V arch code.  I've left it
within an "#ifdef CONFIG_EARLY_PRINTK" despite always having
EARLY_PRINTK support on RISC-V just in case someone wants to remove
it.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:30 -07:00
Jim Wilson 758914fea2
RISC-V: Don't increment sepc after breakpoint.
Adding 4 to sepc is pointless, and is wrong if we executed a 2-byte
compressed breakpoint.  This plus a corresponding gdb patch allows
compressed breakpoints to work in gdb.  Gdb maintainers have already
agreed that this is the right approach.

Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:30 -07:00
Palmer Dabbelt 4938c79bd0
RISC-V: Use KBUILD_CFLAGS instead of KCFLAGS when building the vDSO
If you use a 64-bit compiler to build a 32-bit kernel then you'll get an
error when building the vDSO due to a library mismatch.  The happens
because the relevant "-march" argument isn't supplied to the GCC run
that generates one of the vDSO intermediate files.

I'm not actually sure what the right thing to do here is as I'm not
particularly familiar with the kernel build system.  I poked the
documentation and it appears that KCFLAGS is the correct thing to do
(it's suggested that should be used when building modules), but we set
KBUILD_CFLAGS in arch/riscv/Makefile.

This does at least fix the build error.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13 08:31:28 -07:00
Palmer Dabbelt 9a6a51154f
RISC-V: Fix the rv32i kernel build
These patches for building 32-bit RISC-V kernel.
 - Fix the compile errors and warnings on RV32I.
 - Fix some incompatible problem on RV32I.
 - Add format.h for compatible of print format.

The fixed width integer types format for Elf_Addr will move to
generic header by another patch. For now, there are some warning
about unexpected argument of type on RV32I.

Change in v1:
 - Fix some error in v1
 - Remove implementation of fixed width integer types format for Elf_Addr.
2018-07-04 14:12:53 -07:00
Jim Wilson 1db9b80980
RISC-V: Fix PTRACE_SETREGSET bug.
In riscv_gpr_set, pass regs instead of &regs to user_regset_copyin to fix
gdb segfault.

Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-07-04 14:12:47 -07:00
Palmer Dabbelt 8606544890
RISC-V: Don't include irq-riscv-intc.h
This file has never existed in the upstream kernel, but it's guarded by
an #ifdef that's also never existed in the upstream kernel.  As a part
of our interrupt controller refactoring this header is no longer
necessary, but this reference managed to sneak in anyway.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-07-04 14:12:42 -07:00
Rob Herring f67f10b8a6
riscv: remove unnecessary of_platform_populate call
The DT core will call of_platform_default_populate, so it is not
necessary for arch specific code to call it unless there are custom
match entries, auxdata or parent device. Neither of those apply here, so
remove the call.

Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-07-04 14:12:38 -07:00
Andreas Schwab 781c8fe2da
RISC-V: fix R_RISCV_ADD32/R_RISCV_SUB32 relocations
The R_RISCV_ADD32/R_RISCV_SUB32 relocations should add/subtract the
address of the symbol (without overflow check), not its contents.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-07-04 14:12:34 -07:00
Zong Li 7df8500217
RISC-V: Change variable type for 32-bit compatible
Signed-off-by: Zong Li <zong@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-07-04 13:56:52 -07:00
Linus Torvalds 6a4d4b3253 RISC-V Updates for the 4.18 Merge Window
This tag contains some small RISC-V updates I'd like to target for 4.18.
 They are all fairly small this time.  Here's a short summary, there's
 more info in the commits/merges.
 
 * A fix to __clear_user to respect the passed arguments.
 * Enough support for the perf subsystem to work with RISC-V's ISA
   defined performance counters.
 * Support for sparse and cleanups suggested by it.
 * Support for R_RISCV_32 (a relocation, not the 32-bit ISA).
 * Some MAINTAINERS cleanups.
 * The addition of CONFIG_HVC_RISCV_SBI to our defconfig, as it's always
   present.
 
 I've given these a simple build+boot test.
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Merge tag 'riscv-for-linus-4.18-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains some small RISC-V updates I'd like to target for 4.18.

  They are all fairly small this time. Here's a short summary, there's
  more info in the commits/merges:

   - a fix to __clear_user to respect the passed arguments.

   - enough support for the perf subsystem to work with RISC-V's ISA
     defined performance counters.

   - support for sparse and cleanups suggested by it.

   - support for R_RISCV_32 (a relocation, not the 32-bit ISA).

   - some MAINTAINERS cleanups.

   - the addition of CONFIG_HVC_RISCV_SBI to our defconfig, as it's
     always present.

  I've given these a simple build+boot test"

* tag 'riscv-for-linus-4.18-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  RISC-V: Add CONFIG_HVC_RISCV_SBI=y to defconfig
  RISC-V: Handle R_RISCV_32 in modules
  riscv/ftrace: Export _mcount when DYNAMIC_FTRACE isn't set
  riscv: add riscv-specific predefines to CHECKFLAGS
  riscv: split the declaration of __copy_user
  riscv: no __user for probe_kernel_address()
  riscv: use NULL instead of a plain 0
  perf: riscv: Add Document for Future Porting Guide
  perf: riscv: preliminary RISC-V support
  MAINTAINERS: Update Albert's email, he's back at Berkeley
  MAINTAINERS: Add myself as a maintainer for SiFive's drivers
  riscv: Fix the bug in memory access fixup code
2018-06-16 06:42:43 +09:00
Palmer Dabbelt e0e0c87c02
RISC-V: Make our port sparse-clean
This patch set contains a handful of fixes that clean up the sparse
results for the RISC-V port.  These patches shouldn't have any
functional difference.  The patches:

* Use NULL instead of 0.
* Clean up __user annotations.
* Split __copy_user into two functions, to make the __user annotations
  valid.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2018-06-11 09:09:49 -07:00
Andreas Schwab 77aa85de16
RISC-V: Handle R_RISCV_32 in modules
With CONFIG_MODVERSIONS=y the R_RISCV_32 relocation is used by the
__kcrctab section.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-11 09:04:34 -07:00
Alan Kao 1dd985229d
riscv/ftrace: Export _mcount when DYNAMIC_FTRACE isn't set
The EXPORT_SYMBOL(_mcount) for RISC-V ended up inside a
CONFIG_DYNAMIC_FTRACE ifdef.  If you enable modules without enabling
CONFIG_DYNAMIC_FTRACE then you'll get a build error without this patch
because the modules won't be able to find _mcount.

The new behavior is to export _mcount whenever CONFIG_FUNCTION_TRACER is
defined.  This matches what every other architecture is doing.

Signed-off-by: Alan Kao <alankao@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Cc: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-11 09:04:03 -07:00
Luc Van Oostenryck 86406d51d3
riscv: split the declaration of __copy_user
We use a single __copy_user assembly function to copy memory both from
and to userspace. While this works, it triggers sparse errors because
we're implicitly casting between the kernel and user address spaces by
calling __copy_user.

This patch splits the C declaration into a pair of functions,
__asm_copy_{to,from}_user, that have sane semantics WRT __user. This
split make things fine from sparse's point of view. The assembly
implementation keeps a single definition but add a double ENTRY() for it,
one for __asm_copy_to_user and another one for __asm_copy_from_user.
The result is a spare-safe implementation that pays no performance
or code size penalty.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-09 12:34:31 -07:00
Linus Torvalds 410feb75de arm64 updates for 4.18:
- Spectre v4 mitigation (Speculative Store Bypass Disable) support for
   arm64 using SMC firmware call to set a hardware chicken bit
 
 - ACPI PPTT (Processor Properties Topology Table) parsing support and
   enable the feature for arm64
 
 - Report signal frame size to user via auxv (AT_MINSIGSTKSZ). The
   primary motivation is Scalable Vector Extensions which requires more
   space on the signal frame than the currently defined MINSIGSTKSZ
 
 - ARM perf patches: allow building arm-cci as module, demote dev_warn()
   to dev_dbg() in arm-ccn event_init(), miscellaneous cleanups
 
 - cmpwait() WFE optimisation to avoid some spurious wakeups
 
 - L1_CACHE_BYTES reverted back to 64 (for performance reasons that have
   to do with some network allocations) while keeping ARCH_DMA_MINALIGN
   to 128. cache_line_size() returns the actual hardware Cache Writeback
   Granule
 
 - Turn LSE atomics on by default in Kconfig
 
 - Kernel fault reporting tidying
 
 - Some #include and miscellaneous cleanups
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Apart from the core arm64 and perf changes, the Spectre v4 mitigation
  touches the arm KVM code and the ACPI PPTT support touches drivers/
  (acpi and cacheinfo). I should have the maintainers' acks in place.

  Summary:

   - Spectre v4 mitigation (Speculative Store Bypass Disable) support
     for arm64 using SMC firmware call to set a hardware chicken bit

   - ACPI PPTT (Processor Properties Topology Table) parsing support and
     enable the feature for arm64

   - Report signal frame size to user via auxv (AT_MINSIGSTKSZ). The
     primary motivation is Scalable Vector Extensions which requires
     more space on the signal frame than the currently defined
     MINSIGSTKSZ

   - ARM perf patches: allow building arm-cci as module, demote
     dev_warn() to dev_dbg() in arm-ccn event_init(), miscellaneous
     cleanups

   - cmpwait() WFE optimisation to avoid some spurious wakeups

   - L1_CACHE_BYTES reverted back to 64 (for performance reasons that
     have to do with some network allocations) while keeping
     ARCH_DMA_MINALIGN to 128. cache_line_size() returns the actual
     hardware Cache Writeback Granule

   - Turn LSE atomics on by default in Kconfig

   - Kernel fault reporting tidying

   - Some #include and miscellaneous cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (53 commits)
  arm64: Fix syscall restarting around signal suppressed by tracer
  arm64: topology: Avoid checking numa mask for scheduler MC selection
  ACPI / PPTT: fix build when CONFIG_ACPI_PPTT is not enabled
  arm64: cpu_errata: include required headers
  arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the file
  arm64: signal: Report signal frame size to userspace via auxv
  arm64/sve: Thin out initialisation sanity-checks for sve_max_vl
  arm64: KVM: Add ARCH_WORKAROUND_2 discovery through ARCH_FEATURES_FUNC_ID
  arm64: KVM: Handle guest's ARCH_WORKAROUND_2 requests
  arm64: KVM: Add ARCH_WORKAROUND_2 support for guests
  arm64: KVM: Add HYP per-cpu accessors
  arm64: ssbd: Add prctl interface for per-thread mitigation
  arm64: ssbd: Introduce thread flag to control userspace mitigation
  arm64: ssbd: Restore mitigation status on CPU resume
  arm64: ssbd: Skip apply_ssbd if not using dynamic mitigation
  arm64: ssbd: Add global mitigation state accessor
  arm64: Add 'ssbd' command-line option
  arm64: Add ARCH_WORKAROUND_2 probing
  arm64: Add per-cpu infrastructure to call ARCH_WORKAROUND_2
  arm64: Call ARCH_WORKAROUND_2 on transitions between EL0 and EL1
  ...
2018-06-08 11:10:58 -07:00
Luc Van Oostenryck 9bf97390b3
riscv: no __user for probe_kernel_address()
In is_valid_bugaddr(), probe_kernel_address() is called with
the PC casted to (bug_inst_t __user *) but this function
only take a plain void* as argument, not a __user pointer.

Fix this by removing the unnneded __user in the cast.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-07 08:01:52 -07:00
Linus Torvalds 93e95fa574 Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo updates from Eric Biederman:
 "This set of changes close the known issues with setting si_code to an
  invalid value, and with not fully initializing struct siginfo. There
  remains work to do on nds32, arc, unicore32, powerpc, arm, arm64, ia64
  and x86 to get the code that generates siginfo into a simpler and more
  maintainable state. Most of that work involves refactoring the signal
  handling code and thus careful code review.

  Also not included is the work to shrink the in kernel version of
  struct siginfo. That depends on getting the number of places that
  directly manipulate struct siginfo under control, as it requires the
  introduction of struct kernel_siginfo for the in kernel things.

  Overall this set of changes looks like it is making good progress, and
  with a little luck I will be wrapping up the siginfo work next
  development cycle"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  signal/sh: Stop gcc warning about an impossible case in do_divide_error
  signal/mips: Report FPE_FLTUNK for undiagnosed floating point exceptions
  signal/um: More carefully relay signals in relay_signal.
  signal: Extend siginfo_layout with SIL_FAULT_{MCEERR|BNDERR|PKUERR}
  signal: Remove unncessary #ifdef SEGV_PKUERR in 32bit compat code
  signal/signalfd: Add support for SIGSYS
  signal/signalfd: Remove __put_user from signalfd_copyinfo
  signal/xtensa: Use force_sig_fault where appropriate
  signal/xtensa: Consistenly use SIGBUS in do_unaligned_user
  signal/um: Use force_sig_fault where appropriate
  signal/sparc: Use force_sig_fault where appropriate
  signal/sparc: Use send_sig_fault where appropriate
  signal/sh: Use force_sig_fault where appropriate
  signal/s390: Use force_sig_fault where appropriate
  signal/riscv: Replace do_trap_siginfo with force_sig_fault
  signal/riscv: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_fault where appropriate
  signal/parisc: Use force_sig_mceerr where appropriate
  signal/openrisc: Use force_sig_fault where appropriate
  signal/nios2: Use force_sig_fault where appropriate
  ...
2018-06-04 15:23:48 -07:00
Alan Kao 178e9fc47a
perf: riscv: preliminary RISC-V support
This patch provide a basic PMU, riscv_base_pmu, which supports two
general hardware event, instructions and cycles.  Furthermore, this
PMU serves as a reference implementation to ease the portings in
the future.

riscv_base_pmu should be able to run on any RISC-V machine that
conforms to the Priv-Spec.  Note that the latest qemu model hasn't
fully support a proper behavior of Priv-Spec 1.10 yet, but work
around should be easy with very small fixes.  Please check
https://github.com/riscv/riscv-qemu/pull/115 for future updates.

Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-06-04 14:02:01 -07:00
Christoph Hellwig 10314e09d0 riscv: add swiotlb support
All RISC-V platforms today lack an IOMMU. However, legacy PCI devices
sometimes require DMA-memory to be in the low 32 bits.  To make this work,
we enable the software-based bounce buffers from swiotlb.  They only impose
overhead when the device in question cannot address the full 64-bit address
space, so a perfect fit.

This patch assumes that DMA is coherent with the processor and the PCI
bus.  It also assumes that the processor and devices share a common
address space. This is true for all RISC-V platforms so far.

[changelog stolen from an earlier patch by Palmer Dabbelt that did the
 more complicated swiotlb wireup before the recent consolidation]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
2018-05-19 08:46:26 +02:00
Jeremy Linton 2ff075c7df drivers: base: cacheinfo: setup DT cache properties early
The original intent in cacheinfo was that an architecture
specific populate_cache_leaves() would probe the hardware
and then cache_shared_cpu_map_setup() and
cache_override_properties() would provide firmware help to
extend/expand upon what was probed. Arm64 was really
the only architecture that was working this way, and
with the removal of most of the hardware probing logic it
became clear that it was possible to simplify the logic a bit.

This patch combines the walk of the DT nodes with the
code updating the cache size/line_size and nr_sets.
cache_override_properties() (which was DT specific) is
then removed. The result is that cacheinfo.of_node is
no longer used as a temporary place to hold DT references
for future calls that update cache properties. That change
helps to clarify its one remaining use (matching
cacheinfo nodes that represent shared caches) which
will be used by the ACPI/PPTT code in the following patches.

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-17 17:27:49 +01:00
Eric W. Biederman 7ff3a7621d signal/riscv: Replace do_trap_siginfo with force_sig_fault
The function force_sig_fault is just the generic version of
do_trap_siginfo with a (void __user *) instead of an unsigned long
parameter for the address.

So just use force_sig_fault to simplify the code.

Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: linux-riscv@lists.infradead.org
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:44:07 -05:00
Eric W. Biederman 4d6a20b135 signal/riscv: Use force_sig_fault where appropriate
Filling in struct siginfo before calling force_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.

Simplify this process by using the helper force_sig_fault.  Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls force_sig_info.

In short about a 5 line reduction in code for every time force_sig_info
is called, which makes the calling function clearer.

Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: linux-riscv@lists.infradead.org
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:44:07 -05:00
Eric W. Biederman 3eb0f5193b signal: Ensure every siginfo we send has all bits initialized
Call clear_siginfo to ensure every stack allocated siginfo is properly
initialized before being passed to the signal sending functions.

Note: It is not safe to depend on C initializers to initialize struct
siginfo on the stack because C is allowed to skip holes when
initializing a structure.

The initialization of struct siginfo in tracehook_report_syscall_exit
was moved from the helper user_single_step_siginfo into
tracehook_report_syscall_exit itself, to make it clear that the local
variable siginfo gets fully initialized.

In a few cases the scope of struct siginfo has been reduced to make it
clear that siginfo siginfo is not used on other paths in the function
in which it is declared.

Instances of using memset to initialize siginfo have been replaced
with calls clear_siginfo for clarity.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-04-25 10:40:51 -05:00
Aurelien Jarno 85602bea29
RISC-V: build vdso-dummy.o with -no-pie
Debian toolcahin defaults to PIE, and I guess that will also be the case
of most distributions. This causes the following build failure:

  AS      arch/riscv/kernel/vdso/getcpu.o
  AS      arch/riscv/kernel/vdso/flush_icache.o
  VDSOLD  arch/riscv/kernel/vdso/vdso.so.dbg
  OBJCOPY arch/riscv/kernel/vdso/vdso.so
  AS      arch/riscv/kernel/vdso/vdso.o
  VDSOLD  arch/riscv/kernel/vdso/vdso-dummy.o
  LD      arch/riscv/kernel/vdso/vdso-syms.o
riscv64-linux-gnu-ld: attempted static link of dynamic object `arch/riscv/kernel/vdso/vdso-dummy.o'
make[2]: *** [arch/riscv/kernel/vdso/Makefile:43: arch/riscv/kernel/vdso/vdso-syms.o] Error 1
make[1]: *** [scripts/Makefile.build:575: arch/riscv/kernel/vdso] Error 2
make: *** [Makefile:1018: arch/riscv/kernel] Error 2

While the root Makefile correctly passes "-fno-PIE" to build individual
object files, the RISC-V kernel also builds vdso-dummy.o as an
executable, which is therefore linked as PIE. Fix that by updating this
specific link rule to also include "-no-pie".

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-24 10:54:46 -07:00
Linus Torvalds 527cd20771 RISC-V changes for 4.17
This tag contains the new features we'd like to incorporate into the
 RISC-V port for 4.17.  We might have a bit more stuff land later in the
 merge window, but I wanted to get this out earlier just so everyone can
 see where we currently stand.
 
 A short summary of the changes is:
 
 * We've added support for dynamic ftrace on RISC-V targets.
 * There have been a handful of cleanups to our atomic and locking
   routines.  They now more closely match the released RISC-V memory
   model draft.
 * Our module loading support has been cleaned up and is now enabled by
   default, despite some limitations still existing.
 * A patch to define COMMANDLINE_FORCE instead of COMMANDLINE_OVERRIDE so
   the generic device tree code picks up handling all our command line
   stuff.
 
 There's more information in the merge commits for each patch set.
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Merge tag 'riscv-for-linus-4.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains the new features we'd like to incorporate into the
  RISC-V port for 4.17. We might have a bit more stuff land later in the
  merge window, but I wanted to get this out earlier just so everyone
  can see where we currently stand.

  A short summary of the changes is:

   - We've added support for dynamic ftrace on RISC-V targets.

   - There have been a handful of cleanups to our atomic and locking
     routines. They now more closely match the released RISC-V memory
     model draft.

   - Our module loading support has been cleaned up and is now enabled
     by default, despite some limitations still existing.

   - A patch to define COMMANDLINE_FORCE instead of COMMANDLINE_OVERRIDE
     so the generic device tree code picks up handling all our command
     line stuff.

  There's more information in the merge commits for each patch set"

* tag 'riscv-for-linus-4.17-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux: (21 commits)
  RISC-V: Rename CONFIG_CMDLINE_OVERRIDE to CONFIG_CMDLINE_FORCE
  RISC-V: Add definition of relocation types
  RISC-V: Enable module support in defconfig
  RISC-V: Support SUB32 relocation type in kernel module
  RISC-V: Support ADD32 relocation type in kernel module
  RISC-V: Support ALIGN relocation type in kernel module
  RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewq
  RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module
  RISC-V: Support CALL relocation type in kernel module
  RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel module
  RISC-V: Add section of GOT.PLT for kernel module
  RISC-V: Add sections of PLT and GOT for kernel module
  riscv/atomic: Strengthen implementations with fences
  riscv/spinlock: Strengthen implementations with fences
  riscv/barrier: Define __smp_{store_release,load_acquire}
  riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
  riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support
  riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support
  riscv/ftrace: Add dynamic function graph tracer support
  riscv/ftrace: Add dynamic function tracer support
  ...
2018-04-04 16:43:47 -07:00
Linus Torvalds 5b1f3dc927 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "The usual pile of boring changes:

   - Consolidate tasklet functions to share code instead of duplicating
     it

   - The first step for making the low level entry handler management on
     multi-platform kernels generic

   - A new sysfs file which allows to retrieve the wakeup state of
     interrupts.

   - Ensure that the interrupt thread follows the effective affinity and
     not the programmed affinity to avoid cross core wakeups.

   - Two new interrupt controller drivers (Microsemi Ocelot and Qualcomm
     PDC)

   - Fix the wakeup path clock handling for Reneasas interrupt chips.

   - Rework the boot time register reset for ARM GIC-V2/3

   - Better suspend/resume support for ARM GIV-V3/ITS

   - Add missing locking to the ARM GIC set_type() callback

   - Small fixes for the irq simulator code

   - SPDX identifiers for the irq core code and removal of boiler plate

   - Small cleanups all over the place"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  openrisc: Set CONFIG_MULTI_IRQ_HANDLER
  arm64: Set CONFIG_MULTI_IRQ_HANDLER
  genirq: Make GENERIC_IRQ_MULTI_HANDLER depend on !MULTI_IRQ_HANDLER
  irqchip/gic: Take lock when updating irq type
  irqchip/gic: Update supports_deactivate static key to modern api
  irqchip/gic-v3: Ensure GICR_CTLR.EnableLPI=0 is observed before enabling
  irqchip: Add a driver for the Microsemi Ocelot controller
  dt-bindings: interrupt-controller: Add binding for the Microsemi Ocelot interrupt controller
  irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn
  irqchip/gic-v3: Don't try to reset AP0Rn
  irqchip/gic-v3: Do not check trigger configuration of partitionned LPIs
  genirq: Remove license boilerplate/references
  genirq: Add missing SPDX identifiers
  genirq/matrix: Cleanup SPDX identifier
  genirq: Cleanup top of file comments
  genirq: Pass desc to __irq_free instead of irq number
  irqchip/gic-v3: Loudly complain about the use of IRQ_TYPE_NONE
  irqchip/gic: Loudly complain about the use of IRQ_TYPE_NONE
  RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler
  genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLER
  ...
2018-04-04 15:19:26 -07:00
Palmer Dabbelt 7a8e7da422
RISC-V: Fixes to module loading
This cleans up the module support that was commited earlier to work with
what's actually emitted from our GCC port as it lands upstream.  Most of
the work here is adding new relocations to the kernel.

There's some limitations on module loading imposed by the kernel:

* The kernel doesn't support linker relaxation, which is necessary to
  support R_RISCV_ALIGN.  In order to get reliable module building
  you're going to need to a GCC that supports the new '-mno-relax',
  which IIRC isn't going to be out until 8.1.0.  It's somewhat unlikely
  that R_RISCV_ALIGN will appear in a module even without '-mno-relax'
  support, so issues shouldn't be common.

* There is no large code model for RISC-V, which means modules must be
  loaded within a 32-bit signed offset of the kernel.  We don't
  currently have any mechanism for ensuring this memory remains free or
  moving pages around, so issues here might be common.

I fixed a singcle merge conflict in arch/riscv/kernel/Makefile.
2018-04-02 20:43:14 -07:00
Zong Li 4aad074c9c
RISC-V: Support SUB32 relocation type in kernel module
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:55 -07:00
Zong Li 8e691b1676
RISC-V: Support ADD32 relocation type in kernel module
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:55 -07:00
Zong Li 29e405cd88
RISC-V: Support ALIGN relocation type in kernel module
Just fail on align type. Kernel modules loader didn't do relax
like linker, it is difficult to remove or migrate the code,
but the remnant nop instructions harm the performaace of module.
We expect the building module with the no-relax option.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:55 -07:00
Zong Li 56ea45ae23
RISC-V: Support RVC_BRANCH/JUMP relocation type in kernel modulewq
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:55 -07:00
Zong Li e7456e696b
RISC-V: Support HI20/LO12_I/LO12_S relocation type in kernel module
HI20 and LO12_I/LO12_S relocate the absolute address, the range of
offset must in 32-bit.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:55 -07:00
Zong Li e1910c72bd
RISC-V: Support CALL relocation type in kernel module
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:54 -07:00
Zong Li da975dd481
RISC-V: Support GOT_HI20/CALL_PLT relocation type in kernel module
For CALL_PLT, emit the plt entry only when offset is more than 32-bit.

For PCREL_LO12, it uses the location of corresponding HI20 to
get the address of external symbol. It should check the HI20 type
is the PCREL_HI20 or GOT_HI20, because sometime the location will
have two or more relocation types.
For example:
0:   00000797                auipc   a5,0x0
                     0: R_RISCV_ALIGN        *ABS*
                     0: R_RISCV_GOT_HI20     SYMBOL
4:   0007b783                ld      a5,0(a5) # 0 <SYMBOL>
                     4: R_RISCV_PCREL_LO12_I .L0
                     4: R_RISCV_RELAX        *ABS*

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:54 -07:00
Zong Li b8bde0ef12
RISC-V: Add section of GOT.PLT for kernel module
Separate the function symbol address from .plt to .got.plt section.

The original plt entry has trampoline code with symbol address,
there is a 32-bit padding bwtween jar instruction and symbol address.

Extract the symbol address to .got.plt to reduce the module size.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:54 -07:00
Zong Li ab1ef68e54
RISC-V: Add sections of PLT and GOT for kernel module
The address of external symbols will locate more than 32-bit offset
in 64-bit kernel with sv39 or sv48 virtual addressing.

Module loader emits the GOT and PLT entries for data symbols and
function symbols respectively.

The PLT entry is a trampoline code for jumping to the 64-bit
real address. The GOT entry is just the data symbol address.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 20:00:54 -07:00
Alan Kao b785ec129b
riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support
In walk_stackframe, the pc now receives the address from calling
ftrace_graph_ret_addr instead of manual calculation.

Note that the original calculation,
        pc = frame->ra - 4
is buggy when the instruction at the return address happened to be a
compressed inst. But since it is not a critical part of ftrace, it is
ignored for now to ease the review process.

Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:13 -07:00
Alan Kao aea4c671fb
riscv/ftrace: Add DYNAMIC_FTRACE_WITH_REGS support
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:13 -07:00
Alan Kao 71e736a7d6
riscv/ftrace: Add ARCH_SUPPORTS_FTRACE_OPS support
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:12 -07:00
Alan Kao bc1a4c3a84
riscv/ftrace: Add dynamic function graph tracer support
Once the function_graph tracer is enabled, a filtered function has the
following call sequence:

* ftracer_caller         ==> on/off by ftrace_make_call/ftrace_make_nop
* ftrace_graph_caller
* ftrace_graph_call      ==> on/off by ftrace_en/disable_ftrace_graph_caller
* prepare_ftrace_return

Considering the following DYNAMIC_FTRACE_WITH_REGS feature, it would be
more extendable to have a ftrace_graph_caller function, instead of
calling prepare_ftrace_return directly in ftrace_caller.

Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:12 -07:00
Alan Kao c15ac4fd60
riscv/ftrace: Add dynamic function tracer support
We now have dynamic ftrace with the following added items:

* ftrace_make_call, ftrace_make_nop (in kernel/ftrace.c)
  The two functions turn each recorded call site of filtered functions
  into a call to ftrace_caller or nops

* ftracce_update_ftrace_func (in kernel/ftrace.c)
  turns the nops at ftrace_call into a call to a generic entry for
  function tracers.

* ftrace_caller (in kernel/mcount-dyn.S)
  The entry where each _mcount call sites calls to once they are
  filtered to be traced.

Also, this patch fixes the semantic problems in mcount.S, which will be
treated as only a reference implementation once we have the dynamic
ftrace.

Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-04-02 19:59:12 -07:00
Dominik Brodowski a90f590a1b mm: add ksys_mmap_pgoff() helper; remove in-kernel calls to sys_mmap_pgoff()
Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mmap_pgoff().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:11 +02:00
Palmer Dabbelt cc6c98485f RISC-V: Move to the new GENERIC_IRQ_MULTI_HANDLER handler
The existing mechanism for handling IRQs on RISC-V is pretty ugly: the irq
entry code selects the handler via Kconfig dependencies.

Use the new generic IRQ handling infastructure, which allows boot time
registration of the low level entry handler.

This does add an additional load to the interrupt latency, but there's a
lot of tuning left to be done there on RISC-V so it's OK for now.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Cc: jonas@southpole.se
Cc: catalin.marinas@arm.com
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux@armlinux.org.uk
Cc: stefan.kristiansson@saunalahti.fi
Cc: openrisc@lists.librecores.org
Cc: linux-riscv@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180307235731.22627-3-palmer@sifive.com
2018-03-14 21:46:29 +01:00
Michael Clark 8b08f50152
Rename sbi_save to parse_dtb to improve code readability
The sbi_ prefix would seem to indicate an SBI interface, and save is not
very specific. After applying this patch, reading head.S makes more sense.

Signed-off-by: Michael Clark <michaeljclark@mac.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20 10:56:26 -08:00
zongbox@gmail.com bcae803a21
RISC-V: Enable IRQ during exception handling
Interrupt is allowed during exception handling.
There are warning messages if the kernel enables the configuration
'CONFIG_DEBUG_ATOMIC_SLEEP=y'.

BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23
in_atomic(): 0, irqs_disabled(): 1, pid: 43, name: ash
CPU: 0 PID: 43 Comm: ash Tainted:  G	 W	 4.15.0-rc8-00089-g89ffdae-dirty #17
Call Trace:
[<000000009abb1587>] walk_stackframe+0x0/0x7a
[<00000000d4f3d088>] ___might_sleep+0x102/0x11a
[<00000000b1fd792a>] down_read+0x18/0x28
[<000000000289ec01>] do_page_fault+0x86/0x2f6
[<00000000012441f6>] _do_fork+0x1b4/0x1e0
[<00000000f46c3e3b>] ret_from_syscall+0xa/0xe

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-02-20 10:56:14 -08:00
Linus Torvalds 413879a10b RISC-V changes for 4.16
This tag contains the fixes we'd like to target for the 4.16 merge
 window.  It's not as much as I was originally hoping to do but between
 glibc, the chip, and FOSDEM there just wasn't enough time to get
 everything put together.  As such, this merge window is essentially just
 going to be small changes.  This includes mostly cleanups:
 
 * A build fix failure to the audit test cases.  RISC-V doesn't have
   renameat because the generic syscall ABI moved to renameat2 by the
   time of our port.  The syscall audit test cases don't understand this,
   so I added a trivial fix.  This went through mailing list review
   during the 4.15 merge window, but nobody has picked it up so I think
   it's best to just do this here.
 * The removal of our command-line argument processing code.  The
   "mem_end" stuff was broken and the rest duplicated generic device tree
   code.  The generic code was already being called.
 * Some unused/redundant code has been removed, including
   __ARCH_HAVE_MMU, current_pgdir, and the initialization of init_mm.pgd.
 * SUM is disabled upon taking a trap, which means that user memory is
   protected during traps taking inside copy_{to,from}_user().
 * The sptbr CSR has been renamed to satp in C code.  We haven't changed
   the assembly code in order to maintain compatibility with binutils
   2.29, which doesn't understand the new name.
 
 Additionally, we're adding some new features:
 
 * Basic ftrace support, thanks to Alan Kao!
 * Support for ZONE_DMA32.  This is necessary for all the normal reasons,
   but also to deal with a deficiency in the Xilinx PCIe controller we're
   using on our FPGA-based systems.  While the ZONE_DMA32 addition should
   be sufficient for most uses, it doesn't complete the fix for the
   Xilinx controller.
 * TLB shootdowns now only target the harts where they're necessary,
   instead of applying to all harts in the system.
 
 These patches have all been sitting on our linux-next branch for a while
 now.  Due to time constraints this is all I feel comfortable submitting
 during the 4.16 merge window, hopefully we'll do better next time!
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Merge tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains the fixes we'd like to target for the 4.16 merge window.
  It's not as much as I was originally hoping to do but between glibc,
  the chip, and FOSDEM there just wasn't enough time to get everything
  put together. As such, this merge window is essentially just going to
  be small changes. This includes mostly cleanups:

   - A build fix failure to the audit test cases.

     RISC-V doesn't have renameat because the generic syscall ABI moved
     to renameat2 by the time of our port. The syscall audit test cases
     don't understand this, so I added a trivial fix. This went through
     mailing list review during the 4.15 merge window, but nobody has
     picked it up so I think it's best to just do this here.

   - The removal of our command-line argument processing code. The
     "mem_end" stuff was broken and the rest duplicated generic device
     tree code. The generic code was already being called.

   - Some unused/redundant code has been removed, including
     __ARCH_HAVE_MMU, current_pgdir, and the initialization of
     init_mm.pgd.

   - SUM is disabled upon taking a trap, which means that user memory is
     protected during traps taking inside copy_{to,from}_user().

   - The sptbr CSR has been renamed to satp in C code. We haven't
     changed the assembly code in order to maintain compatibility with
     binutils 2.29, which doesn't understand the new name.

  Additionally, we're adding some new features:

   - Basic ftrace support, thanks to Alan Kao!

   - Support for ZONE_DMA32.

     This is necessary for all the normal reasons, but also to deal with
     a deficiency in the Xilinx PCIe controller we're using on our
     FPGA-based systems. While the ZONE_DMA32 addition should be
     sufficient for most uses, it doesn't complete the fix for the
     Xilinx controller.

   - TLB shootdowns now only target the harts where they're necessary,
     instead of applying to all harts in the system.

  These patches have all been sitting on our linux-next branch for a
  while now. Due to time constraints this is all I feel comfortable
  submitting during the 4.16 merge window, hopefully we'll do better
  next time!"

[ Note to self: "harts" is RISC-V speak for "hardware threads".  I had
  to look that up.    - Linus ]

* tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  riscv: inline set_pgdir into its only caller
  riscv: rename sptbr to satp
  riscv: don't read back satp in paging_init
  riscv: remove the unused current_pgdir function
  riscv: add ZONE_DMA32
  RISC-V: Limit the scope of TLB shootdowns
  riscv: disable SUM in the exception handler
  riscv: remove redundant unlikely()
  riscv: remove unused __ARCH_HAVE_MMU define
  riscv/ftrace: Add basic support
  RISC-V: Remove mem_end command line processing
  RISC-V: Remove duplicate command-line parsing logic
  audit: Avoid build failures on systems without renameat
2018-02-07 11:33:08 -08:00
Linus Torvalds 40b9672a2f Merge branch 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull asm/uaccess.h whack-a-mole from Al Viro:
 "It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop
  cropping up..."

* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h
  riscv: use linux/uaccess.h, not asm/uaccess.h...
  ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h
2018-01-31 19:18:12 -08:00
Christoph Hellwig 7549cdf59d
riscv: rename sptbr to satp
satp is the name used by the current privileged spec 1.10, use it
instead of the old name.  The most recent release binutils release
(2.29) doesn't know about the satp name yet, so stick to the name from
the previous privileged ISA release and comment on the fact.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:16:12 -08:00
Christoph Hellwig 5ec9c4ff04
riscv: add ZONE_DMA32
This patch allows devices that require memory that can be addressed
using 32-bit addresses to work easily on RISC-V systems.  The newly
improved dma-direct ops will tap into this pool automatically for
32-bit addressing.

Based on an earlier patch from Wesley W. Terpstra.

CC: Wesley W. Terpstra <terpstra@sifive.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:14:27 -08:00
Christoph Hellwig fe9b842f72
riscv: disable SUM in the exception handler
The SUM bit is enabled at the beginning of the copy_{to,from}_user and
{get,put}_user routines, and cleared before they return.  But these user
copy helper can be interrupted by exceptions, in which case the SUM bit
will remain set, which leads to elevated privileges for the code running
in exception context, as that can now access userspace address space
unconditionally.  This frequently happens when the user copy routines
access freshly allocated user memory that hasn't been faulted in, and a
pagefault needs to be taken before the user copy routines can continue.

Fix this by unconditionally clearing SUM when the exception handler is
called - the restore code will automatically restore it based on the
saved value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:12:38 -08:00
Tobias Klauser 509009ccfa
riscv: remove redundant unlikely()
IS_ERR_VALUE() already implies unlikely(), so it can be omitted.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:12:06 -08:00
Alan Kao 10626c32e3
riscv/ftrace: Add basic support
This patch contains basic ftrace support for RV64I platform.
Specifically, function tracer (HAVE_FUNCTION_TRACER), function graph
tracer (HAVE_FUNCTION_GRAPH_TRACER), and a frame pointer test
(HAVE_FUNCTION_GRAPH_FP_TEST) are implemented following the
instructions in Documentation/trace/ftrace-design.txt.

Note that the functions in both ftrace.c and setup.c should not be
hooked with the compiler's -pg option: to prevent infinite self-
referencing for the former, and to ignore early setup stuff for the
latter.

Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:10:54 -08:00
Palmer Dabbelt 5d44bf2065
RISC-V: Remove mem_end command line processing
This is just some cruft left over from before the port converted to
device tree.  The right way to handle memory regions is to specify them
in the device tree, which BBL (our simplest bootloader) is already
capable of doing.  This patch simply removes the cruft.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:09:53 -08:00
Michael Clark 3e076a7e04
RISC-V: Remove duplicate command-line parsing logic
builtin_cmdline handling is present in drivers/of/fdt.c so the
duplicate logic in arch/riscv/setup.c results in duplication of
the builtin command line. e.g. CONFIG_CMDLINE="root=/dev/vda ro"
gets appended twice and gives "root=/dev/vda ro root=/dev/vda ro"

Before this patch:

[    0.000000] Kernel command line: root=/dev/vda ro root=/dev/vda ro

After this patch:

[    0.000000] Kernel command line: root=/dev/vda ro

Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30 19:09:52 -08:00
Christoph Hellwig 1125203c13
riscv: rename SR_* constants to match the spec
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07 15:14:39 -08:00
Palmer Dabbelt 9e49a4ed07
RISC-V: Make __NR_riscv_flush_icache visible to userspace
We were hoping to avoid making this visible to userspace, but it looks
like we're going to have to because QEMU's user-mode emulation doesn't
want to emulate a vDSO.  Having vDSO-only system calls was a bit
unothodox anyway, so I think in this case it's OK to just make the
actual system call number public.

This patch simply moves the definition of __NR_riscv_flush_icache
availiable to userspace, which results in the deletion of the now empty
vdso-syscalls.h.

Changes since v1:

* I've moved the definition into uapi/asm/syscalls.h rathen than
  uapi/asm/unistd.h.  This allows me to keep asm/unistd.h, so we can
  keep the syscall table macros sane.
* As a side effect of the above, this no longer disables all system
  calls on RISC-V.  Whoops!

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07 15:14:37 -08:00
Palmer Dabbelt 27b0174525
RISC-V: Remove unused CONFIG_HVC_RISCV_SBI code
This is code that probably should never have made it into the kernel in
the first place: it depends on a driver that hadn't been reviewed yet.
During the HVC_SBI_RISCV review process a better way of doing this was
suggested, but that means this code is defunct.  It's compile-time
disabled in 4.15 because the driver isn't in, so I think it's safe to
just remove this for now.

CC: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-11 07:51:09 -08:00
Dan Carpenter 86ad5c97ce
RISC-V: Logical vs Bitwise typo
In the current code, there is a ! logical NOT where a bitwise ~ NOT was
intended.  It means that we never return -EINVAL.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-12-11 07:51:06 -08:00
Al Viro 5e454b5457 riscv: use linux/uaccess.h, not asm/uaccess.h...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-12-04 18:01:01 -05:00
Palmer Dabbelt 3b62de26cf
RISC-V: Fixes for clean allmodconfig build
Olaf said: Here's a short series of patches that produces a working
allmodconfig. Would be nice to see them go in so we can add build
coverage.

I've dropped patches 8 and 10 from the original set:

* [PATCH 08/10] (RISC-V: Set __ARCH_WANT_RENAMEAT to pick up generic
  version) has a better fix that I've sent out for review, we don't want
  renameat.
* [PATCH 10/10] (input: joystick: riscv has get_cycles) has already been
  taken into Dmitry Torokhov's tree.
2017-12-01 13:31:31 -08:00
Palmer Dabbelt 0e710ac652 RISC-V: Clean up an unused include
We used to have some cmpxchg syscalls.  They're no longer there, so we
no longer need the include.

CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:29 -08:00
Andrew Waterman 921ebd8f2c RISC-V: Allow userspace to flush the instruction cache
Despite RISC-V having a direct 'fence.i' instruction available to
userspace (which we can't trap!), that's not actually viable when
running on Linux because the kernel might schedule a process on another
hart.  There is no way for userspace to handle this without invoking the
kernel (as it doesn't know the thread->hart mappings), so we've defined
a RISC-V specific system call to flush the instruction cache.

This patch adds both a system call and a VDSO entry.  If possible, we'd
like to avoid having the system call be considered part of the
user-facing ABI and instead restrict that to the VDSO entry -- both just
in general to avoid having additional user-visible ABI to maintain, and
because we'd prefer that users just call the VDSO entry because there
might be a better way to do this in the future (ie, one that doesn't
require entering the kernel).

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:29 -08:00
Andrew Waterman 08f051eda3 RISC-V: Flush I$ when making a dirty page executable
The RISC-V ISA allows for instruction caches that are not coherent WRT
stores, even on a single hart.  As a result, we need to explicitly flush
the instruction cache whenever marking a dirty page as executable in
order to preserve the correct system behavior.

Local instruction caches aren't that scary (our implementations actually
flush the cache, but RISC-V is defined to allow higher-performance
implementations to exist), but RISC-V defines no way to perform an
instruction cache shootdown.  When explicitly asked to do so we can
shoot down remote instruction caches via an IPI, but this is a bit on
the slow side.

Instead of requiring an IPI to all harts whenever marking a page as
executable, we simply flush the currently running harts.  In order to
maintain correct behavior, we additionally mark every other hart as
needing a deferred instruction cache which will be taken before anything
runs on it.

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:25 -08:00
Olof Johansson 4bde63286a RISC-V: Provide stub of setup_profiling_timer()
Fixes the following on allmodconfig build:

profile.c:(.text+0x3e4): undefined reference to `setup_profiling_timer'

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:12:15 -08:00
Olof Johansson 24948b7ec0 RISC-V: Export some expected symbols for modules
These are the ones needed by current allmodconfig, so add them instead
of everything other architectures are exporting -- the rest can be
added on demand later if needed.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:01:10 -08:00
Olof Johansson 83e7b8769a RISC-V: move empty_zero_page definition to C and export it
Needed by some modules (exported by other architectures).

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 10:01:10 -08:00
Andrew Waterman 28dfbe6ed4 RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu
For now these are just placeholders that execute the syscall.  We will
later optimize them to avoid kernel crossings, but we'd like to have the
VDSO entries from the first released kernel version to make the ABI
simpler.

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-27 07:51:39 -08:00
Palmer Dabbelt b7e5a59150 RISC-V: Remove __vdso_cmpxchg{32,64} symbol versions
These were left over from an earlier version of the port.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-27 07:51:39 -08:00
Palmer Dabbelt fbe934d69e RISC-V: Build Infrastructure
This patch contains all the build infrastructure that actually enables
the RISC-V port.  This includes Makefiles, linker scripts, and Kconfig
files.  It also contains the only top-level change, which adds RISC-V to
the list of architectures that need a sed run to produce the ARCH
variable when building locally.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:49 -07:00
Palmer Dabbelt e2c0cdfba7 RISC-V: User-facing API
This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling.  It also contains some generic code that is ABI visible.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:48 -07:00
Palmer Dabbelt 7db91e57a0 RISC-V: Task implementation
This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:46 -07:00
Palmer Dabbelt 5d8544e2d0 RISC-V: Generic library routines and assembly
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00
Palmer Dabbelt 76d2a0493a RISC-V: Init and Halt Code
This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:44 -07:00