Commit Graph

208 Commits

Author SHA1 Message Date
Will Deacon
0a0d111d40 arm64: cpufeature: Pass capability structure to ->enable callback
In order to invoke the CPU capability ->matches callback from the ->enable
callback for applying local-CPU workarounds, we need a handle on the
capability structure.

This patch passes a pointer to the capability structure to the ->enable
callback.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08 18:43:36 +00:00
Will Deacon
179a56f6f9 arm64: Take into account ID_AA64PFR0_EL1.CSV3
For non-KASLR kernels where the KPTI behaviour has not been overridden
on the command line we can use ID_AA64PFR0_EL1.CSV3 to determine whether
or not we should unmap the kernel whilst running at EL0.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08 18:43:34 +00:00
Dongjiu Geng
3b3b681097 arm64: v8.4: Support for new floating point multiplication instructions
ARM v8.4 extensions add new neon instructions for performing a
multiplication of each FP16 element of one vector with the corresponding
FP16 element of a second vector, and to add or subtract this without an
intermediate rounding to the corresponding FP32 element in a third vector.

This patch detects this feature and let the userspace know about it via a
HWCAP bit and MRS emulation.

Cc: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-05 11:29:48 +00:00
Dave Martin
3fab39997a arm64/sve: Report SVE to userspace via CPUID only if supported
Currently, the SVE field in ID_AA64PFR0_EL1 is visible
unconditionally to userspace via the CPU ID register emulation,
irrespective of the kernel config.  This means that if a kernel
configured with CONFIG_ARM64_SVE=n is run on SVE-capable hardware,
userspace will see SVE reported as present in the ID regs even
though the kernel forbids execution of SVE instructions.

This patch makes the exposure of the SVE field in ID_AA64PFR0_EL1
conditional on CONFIG_ARM64_SVE=y.

Since future architecture features are likely to encounter a
similar requirement, this patch adds a suitable helper macros for
use when declaring config-conditional ID register fields.

Fixes: 43994d824e ("arm64/sve: Detect SVE and activate runtime support")
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-14 15:14:30 +00:00
Will Deacon
ea1e3de85e arm64: entry: Add fake CPU feature for unmapping the kernel at EL0
Allow explicit disabling of the entry trampoline on the kernel command
line (kpti=off) by adding a fake CPU feature (ARM64_UNMAP_KERNEL_AT_EL0)
that can be used to toggle the alternative sequences in our entry code and
avoid use of the trampoline altogether if desired. This also allows us to
make use of a static key in arm64_kernel_unmapped_at_el0().

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-12-11 13:41:06 +00:00
Linus Torvalds
c9b012e5f4 arm64 updates for 4.15
Plenty of acronym soup here:
 
 - Initial support for the Scalable Vector Extension (SVE)
 - Improved handling for SError interrupts (required to handle RAS events)
 - Enable GCC support for 128-bit integer types
 - Remove kernel text addresses from backtraces and register dumps
 - Use of WFE to implement long delay()s
 - ACPI IORT updates from Lorenzo Pieralisi
 - Perf PMU driver for the Statistical Profiling Extension (SPE)
 - Perf PMU driver for Hisilicon's system PMUs
 - Misc cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The big highlight is support for the Scalable Vector Extension (SVE)
  which required extensive ABI work to ensure we don't break existing
  applications by blowing away their signal stack with the rather large
  new vector context (<= 2 kbit per vector register). There's further
  work to be done optimising things like exception return, but the ABI
  is solid now.

  Much of the line count comes from some new PMU drivers we have, but
  they're pretty self-contained and I suspect we'll have more of them in
  future.

  Plenty of acronym soup here:

   - initial support for the Scalable Vector Extension (SVE)

   - improved handling for SError interrupts (required to handle RAS
     events)

   - enable GCC support for 128-bit integer types

   - remove kernel text addresses from backtraces and register dumps

   - use of WFE to implement long delay()s

   - ACPI IORT updates from Lorenzo Pieralisi

   - perf PMU driver for the Statistical Profiling Extension (SPE)

   - perf PMU driver for Hisilicon's system PMUs

   - misc cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits)
  arm64: Make ARMV8_DEPRECATED depend on SYSCTL
  arm64: Implement __lshrti3 library function
  arm64: support __int128 on gcc 5+
  arm64/sve: Add documentation
  arm64/sve: Detect SVE and activate runtime support
  arm64/sve: KVM: Hide SVE from CPU features exposed to guests
  arm64/sve: KVM: Treat guest SVE use as undefined instruction execution
  arm64/sve: KVM: Prevent guests from using SVE
  arm64/sve: Add sysctl to set the default vector length for new processes
  arm64/sve: Add prctl controls for userspace vector length management
  arm64/sve: ptrace and ELF coredump support
  arm64/sve: Preserve SVE registers around EFI runtime service calls
  arm64/sve: Preserve SVE registers around kernel-mode NEON use
  arm64/sve: Probe SVE capabilities and usable vector lengths
  arm64: cpufeature: Move sys_caps_initialised declarations
  arm64/sve: Backend logic for setting the vector length
  arm64/sve: Signal handling support
  arm64/sve: Support vector length resetting for new processes
  arm64/sve: Core task context handling
  arm64/sve: Low-level CPU setup
  ...
2017-11-15 10:56:56 -08:00
Dave Martin
43994d824e arm64/sve: Detect SVE and activate runtime support
This patch enables detection of hardware SVE support via the
cpufeatures framework, and reports its presence to the kernel and
userspace via the new ARM64_SVE cpucap and HWCAP_SVE hwcap
respectively.

Userspace can also detect SVE using ID_AA64PFR0_EL1, using the
cpufeatures MRS emulation.

When running on hardware that supports SVE, this enables runtime
kernel support for SVE, and allows user tasks to execute SVE
instructions and make of the of the SVE-specific user/kernel
interface extensions implemented by this series.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:21 +00:00
Dave Martin
2e0f2478ea arm64/sve: Probe SVE capabilities and usable vector lengths
This patch uses the cpufeatures framework to determine common SVE
capabilities and vector lengths, and configures the runtime SVE
support code appropriately.

ZCR_ELx is not really a feature register, but it is convenient to
use it as a template for recording the maximum vector length
supported by a CPU, using the LEN field.  This field is similar to
a feature field in that it is a contiguous bitfield for which we
want to determine the minimum system-wide value.  This patch adds
ZCR as a pseudo-register in cpuinfo/cpufeatures, with appropriate
custom code to populate it.  Finding the minimum supported value of
the LEN field is left to the cpufeatures framework in the usual
way.

The meaning of ID_AA64ZFR0_EL1 is not architecturally defined yet,
so for now we just require it to be zero.

Note that much of this code is dormant and SVE still won't be used
yet, since system_supports_sve() remains hardwired to false.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:17 +00:00
Dave Martin
8f1eec57cd arm64: cpufeature: Move sys_caps_initialised declarations
update_cpu_features() currently cannot tell whether it is being
called during early or late secondary boot.  This doesn't
desperately matter for anything it currently does.

However, SVE will need to know here whether the set of available
vector lengths is known or still to be determined when booting a
CPU, so that it can be updated appropriately.

This patch simply moves the sys_caps_initialised stuff to the top
of the file so that it can be used more widely.  There doesn't seem
to be a more obvious place to put it.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03 15:24:17 +00:00
Julien Thierry
6436beeee5 arm64: Fix single stepping in kernel traps
Software Step exception is missing after stepping a trapped instruction.

Ensure SPSR.SS gets set to 0 after emulating/skipping a trapped instruction
before doing ERET.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[will: replaced AARCH32_INSN_SIZE with 4]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-25 11:57:33 +01:00
Suzuki K Poulose
5bdecb7971 arm64: Fix the feature type for ID register fields
Now that the ARM ARM clearly specifies the rules for inferring
the values of the ID register fields, fix the types of the
feature bits we have in the kernel.

As per ARM ARM DDI0487B.b, section D10.1.4 "Principles of the
ID scheme for fields in ID registers" lists the registers to
which the scheme applies along with the exceptions.

This patch changes the relevant feature bits from FTR_EXACT
to FTR_LOWER_SAFE to select the safer value. This will enable
an older kernel running on a new CPU detect the safer option
rather than completely disabling the feature.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-19 17:42:08 +01:00
Suzuki K Poulose
f5e035f869 arm64: Expose support for optional ARMv8-A features
ARMv8-A adds a few optional features for ARMv8.2 and ARMv8.3.
Expose them to the userspace via HWCAPs and mrs emulation.

SHA2-512  - Instruction support for SHA512 Hash algorithm (e.g SHA512H,
	    SHA512H2, SHA512U0, SHA512SU1)
SHA3 	  - SHA3 crypto instructions (EOR3, RAX1, XAR, BCAX).
SM3	  - Instruction support for Chinese cryptography algorithm SM3
SM4 	  - Instruction support for Chinese cryptography algorithm SM4
DP	  - Dot Product instructions (UDOT, SDOT).

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-11 15:28:40 +01:00
Suzuki K Poulose
c0d8832e78 arm64: Ensure the instruction emulation is ready for userspace
We trap and emulate some instructions (e.g, mrs, deprecated instructions)
for the userspace. However the handlers for these are registered as
late_initcalls and the userspace could be up and running from the initramfs
by that time (with populate_rootfs, which is a rootfs_initcall()). This
could cause problems for the early applications ending up in failure
like :

[   11.152061] modprobe[93]: undefined instruction: pc=0000ffff8ca48ff4

This patch promotes the specific calls to core_initcalls, which are
guaranteed to be completed before we hit userspace.

Cc: stable@vger.kernel.org
Cc: Dave Martin <dave.martin@arm.com>
Cc: Matthias Brugger <mbrugger@suse.com>
Cc: James Morse <james.morse@arm.com>
Reported-by: Matwey V. Kornilov <matwey.kornilov@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-10-06 16:35:21 +01:00
Robin Murphy
d50e071fda arm64: Implement pmem API support
Add a clean-to-point-of-persistence cache maintenance helper, and wire
up the basic architectural support for the pmem driver based on it.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[catalin.marinas@arm.com: move arch_*_pmem() functions to arch/arm64/mm/flush.c]
[catalin.marinas@arm.com: change dmb(sy) to dmb(osh)]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-09 12:15:45 +01:00
Robin Murphy
7aac405ebb arm64: Expose DC CVAP to userspace
The ARMv8.2-DCPoP feature introduces persistent memory support to the
architecture, by defining a point of persistence in the memory
hierarchy, and a corresponding cache maintenance operation, DC CVAP.
Expose the support via HWCAP and MRS emulation.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-08-09 11:00:35 +01:00
Mark Rutland
8effeaaf2c arm64: dump cpu_hwcaps at panic time
When debugging a kernel panic(), it can be useful to know which CPU
features have been detected by the kernel, as some code paths can depend
on these (and may have been patched at runtime).

This patch adds a notifier to dump the detected CPU caps (as a hex
string) at panic(), when we log other information useful for debugging.
On a Juno R1 system running v4.12-rc5, this looks like:

[  615.431249] Kernel panic - not syncing: Fatal exception in interrupt
[  615.437609] SMP: stopping secondary CPUs
[  615.441872] Kernel Offset: disabled
[  615.445372] CPU features: 0x02086
[  615.448522] Memory Limit: none

A developer can decode this by looking at the corresponding
<asm/cpucaps.h> bits. For example, the above decodes as:

* bit  1: ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE
* bit  2: ARM64_WORKAROUND_845719
* bit  7: ARM64_WORKAROUND_834220
* bit 13: ARM64_HAS_32BIT_EL0

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Steve Capper <steve.capper@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-22 15:58:20 +01:00
Will Deacon
8dd0ee651d arm64: cpufeature: Fix CPU_OUT_OF_SPEC taint for uniform systems
Commit 3fde2999fa ("arm64: cpufeature: Don't dump useless backtrace on
CPU_OUT_OF_SPEC") changed the cpufeature detection code to use add_taint
instead of WARN_TAINT_ONCE when detecting a heterogeneous system with
mismatched feature support. Unfortunately, this resulted in all systems
getting the taint, regardless of any feature mismatch.

This patch fixes the problem by conditionalising the taint on detecting
a feature mismatch.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-05 11:40:23 +01:00
Will Deacon
3fde2999fa arm64: cpufeature: Don't dump useless backtrace on CPU_OUT_OF_SPEC
Unfortunately, it turns out that mismatched CPU features in big.LITTLE
systems are starting to appear in the wild. Whilst we should continue to
taint the kernel with CPU_OUT_OF_SPEC for features that differ in ways
that we can't fix up, dumping a useless backtrace out of the cpufeature
code is pointless and irritating.

This patch removes the backtrace from the taint.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-05-30 11:07:42 +01:00
Mark Rutland
63a1e1c95e arm64/cpufeature: don't use mutex in bringup path
Currently, cpus_set_cap() calls static_branch_enable_cpuslocked(), which
must take the jump_label mutex.

We call cpus_set_cap() in the secondary bringup path, from the idle
thread where interrupts are disabled. Taking a mutex in this path "is a
NONO" regardless of whether it's contended, and something we must avoid.
We didn't spot this until recently, as ___might_sleep() won't warn for
this case until all CPUs have been brought up.

This patch avoids taking the mutex in the secondary bringup path. The
poking of static keys is deferred until enable_cpu_capabilities(), which
runs in a suitable context on the boot CPU. To account for the static
keys being set later, cpus_have_const_cap() is updated to use another
static key to check whether the const cap keys have been initialised,
falling back to the caps bitmap until this is the case.

This means that users of cpus_have_const_cap() gain should only gain a
single additional NOP in the fast path once the const caps are
initialised, but should always see the current cap value.

The hyp code should never dereference the caps array, since the caps are
initialized before we run the module initcall to initialise hyp. A check
is added to the hyp init code to document this requirement.

This change will sidestep a number of issues when the upcoming hotplug
locking rework is merged.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyniger <marc.zyngier@arm.com>
Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-05-17 17:00:29 +01:00
Catalin Marinas
a5a3237e50 Pre-requisites for the arch timer errata workarounds:
- Allow checking of a CPU-local erratum
 - Add CNTVCT_EL0 trap handler
 - Define Cortex-A73 MIDR
 - Allow an erratum to be match for all revisions of a core
 - Add capability to advertise Cortex-A73 erratum 858921
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Merge tag 'arch-timer-errata-prereq' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into for-next/core

Pre-requisites for the arch timer errata workarounds:

- Allow checking of a CPU-local erratum
- Add CNTVCT_EL0 trap handler
- Define Cortex-A73 MIDR
- Allow an erratum to be match for all revisions of a core
- Add capability to advertise Cortex-A73 erratum 858921

* tag 'arch-timer-errata-prereq' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms:
  arm64: cpu_errata: Add capability to advertise Cortex-A73 erratum 858921
  arm64: cpu_errata: Allow an erratum to be match for all revisions of a core
  arm64: Define Cortex-A73 MIDR
  arm64: Add CNTVCT_EL0 trap handler
  arm64: Allow checking of a CPU-local erratum
2017-04-07 17:04:19 +01:00
Marc Zyngier
8f41375882 arm64: Allow checking of a CPU-local erratum
this_cpu_has_cap() only checks the feature array, and not the errata
one. In order to be able to check for a CPU-local erratum, allow it
to inspect the latter as well.

This is consistent with cpus_have_cap()'s behaviour, which includes
errata already.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-04-07 11:22:08 +01:00
Dave Martin
46823dd17c arm64: cpufeature: Make ID reg accessor naming less counterintuitive
read_system_reg() can readily be confused with read_sysreg(),
whereas these are really quite different in their meaning.

This patches attempts to reduce the ambiguity be reserving "sysreg"
for the actual system register accessors.

read_system_reg() is instead renamed to read_sanitised_ftr_reg(),
to make it more obvious that the Linux-defined sanitised feature
register cache is being accessed here, not the underlying
architectural system registers.

cpufeature.c's internal __raw_read_system_reg() function is renamed
in line with its actual purpose: a form of read_sysreg() that
indexes on (non-compiletime-constant) encoding rather than symbolic
register name.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-04 16:55:41 +01:00
Suzuki K Poulose
c651aae5a7 arm64: v8.3: Support for weaker release consistency
ARMv8.3 adds new instructions to support Release Consistent
processor consistent (RCpc) model, which is weaker than the
RCsc model.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20 16:30:22 +00:00
Suzuki K Poulose
cb567e79fa arm64: v8.3: Support for complex number instructions
ARM v8.3 adds support for new instructions to aid floating-point
multiplication and addition of complex numbers. Expose the support
via HWCAP and MRS emulation

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20 16:30:08 +00:00
Suzuki K Poulose
c8c3798d23 arm64: v8.3: Support for Javascript conversion instruction
ARMv8.3 adds support for a new instruction to perform conversion
from double precision floating point to integer  to match the
architected behaviour of the equivalent Javascript conversion.
Expose the availability via HWCAP and MRS emulation.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20 16:29:28 +00:00
Will Deacon
155433cb36 arm64: cache: Remove support for ASID-tagged VIVT I-caches
As a recent change to ARMv8, ASID-tagged VIVT I-caches are removed
retrospectively from the architecture. Consequently, we don't need to
support them in Linux either.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20 16:16:57 +00:00
Mark Rutland
521c646108 arm64: cpufeature: correctly handle MRS to XZR
In emulate_mrs() we may erroneously write back to the user SP rather
than XZR if we trap an MRS instruction where Xt == 31.

Use the new pt_regs_write_reg() helper to handle this correctly.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 77c97b4ee2 ("arm64: cpufeature: Expose CPUID registers by emulation")
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-02-15 12:20:29 +00:00
Mark Rutland
965861d66f arm64: ensure __raw_read_system_reg() is self-consistent
We recently discovered that __raw_read_system_reg() erroneously mapped
sysreg IDs to the wrong registers.

To ensure that we don't get hit by a similar issue in future, this patch
makes __raw_read_system_reg() use a macro for each case statement,
ensuring that each case reads the correct register.

To ensure that this patch hasn't introduced an issue, I've binary-diffed
the object files before and after this patch. No code or data sections
differ (though some debug section differ due to line numbering
changing).

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-02-02 18:34:38 +00:00
Mark Rutland
7d0928f18b arm64: fix erroneous __raw_read_system_reg() cases
Since it was introduced in commit da8d02d19f ("arm64/capabilities:
Make use of system wide safe value"), __raw_read_system_reg() has
erroneously mapped some sysreg IDs to other registers.

For the fields in ID_ISAR5_EL1, our local feature detection will be
erroneous. We may spuriously detect that a feature is uniformly
supported, or may fail to detect when it actually is, meaning some
compat hwcaps may be erroneous (or not enforced upon hotplug).

This patch corrects the erroneous entries.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: da8d02d19f ("arm64/capabilities: Make use of system wide safe value")
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-02-02 18:34:38 +00:00
Robert Richter
fa5ce3d192 arm64: errata: Provide macro for major and minor cpu revisions
Definition of cpu ranges are hard to read if the cpu variant is not
zero. Provide MIDR_CPU_VAR_REV() macro to describe the full hardware
revision of a cpu including variant and (minor) revision.

Signed-off-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-13 13:15:52 +00:00
Suzuki K Poulose
f92f5ce01e arm64: Advertise support for Rounding double multiply instructions
ARM v8.1 extensions include support for rounding double multiply
add/subtract instructions to the A64 SIMD instructions set. Let
the userspace know about it via a HWCAP bit.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-12 17:19:06 +00:00
Laura Abbott
2077be6783 arm64: Use __pa_symbol for kernel symbols
__pa_symbol is technically the marcro that should be used for kernel
symbols. Switch to this as a pre-requisite for DEBUG_VIRTUAL which
will do bounds checking.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-12 15:05:39 +00:00
Suzuki K Poulose
4aa8a472c3 arm64: Documentation - Expose CPU feature registers
Documentation for the infrastructure to expose CPU feature
register by emulating MRS.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-12 12:31:31 +00:00
Suzuki K Poulose
77c97b4ee2 arm64: cpufeature: Expose CPUID registers by emulation
This patch adds the hook for emulating MRS instruction to
export the 'user visible' value of supported system registers.
We emulate only the following id space for system registers:

 Op0=3, Op1=0, CRn=0, CRm=[0, 4-7]

The rest will fall back to SIGILL. This capability is also
advertised via a new HWCAP_CPUID.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: add missing static keyword to enable_mrs_emulation]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-12 12:31:09 +00:00
Suzuki K Poulose
fe4fbdbcdd arm64: cpufeature: Track user visible fields
Track the user visible fields of a CPU feature register. This will be
used for exposing the value to the userspace. All the user visible
fields of a feature register will be passed on as it is, while the
others would be filled with their respective safe value.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10 17:13:36 +00:00
Suzuki K Poulose
eab43e8873 arm64: cpufeature: Cleanup feature bit tables
This patch does the following clean ups :

1) All undescribed fields of a register are now treated as 'strict'
   with a safe value of 0. Hence we could leave an empty table for
   describing registers which are RAZ.

2) ID_AA64DFR1_EL1 is RAZ and should use the table for RAZ register.

3) ftr_generic32 is used to represent a register with a 32bit feature
   value. Rename this to ftr_singl32 to make it more obvious. Since
   we don't have a 64bit singe feature register, kill ftr_generic.

Based on a patch by Mark Rutland.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10 17:11:23 +00:00
Mark Rutland
564279ff6f arm64: cpufeature: remove explicit RAZ fields
We currently have some RAZ fields described explicitly in our
arm64_ftr_bits arrays. These are inconsistently commented, grouped,
and/or applied, and maintaining these is error-prone.

Luckily, we don't need these at all. We'll never need to inspect RAZ
fields to determine feature support, and init_cpu_ftr_reg() will ensure
that any bits without a corresponding arm64_ftr_bits entry are treated
as RES0 with strict matching requirements. In check_update_ftr_reg()
we'll then compare these bits from the relevant cpuinfo_arm64
structures, and need not store them in a arm64_ftr_reg.

This patch removes the unnecessary arm64_ftr_bits entries for RES0 bits.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10 17:11:23 +00:00
Mark Rutland
b389d7997a arm64: cpufeature: treat unknown fields as RES0
Any fields not defined in an arm64_ftr_bits entry are propagated to the
system-wide register value in init_cpu_ftr_reg(), and while we require
that these strictly match for the sanity checks, we don't update them in
update_cpu_ftr_reg().

Generally, the lack of an arm64_ftr_bits entry indicates that the bits
are currently RES0 (as is the case for the upper 32 bits of all
supposedly 32-bit registers).

A better default would be to use zero for the system-wide value of
unallocated bits, making all register checking consistent, and allowing
for subsequent simplifications to the arm64_ftr_bits arrays.

This patch updates init_cpu_ftr_reg() to treat unallocated bits as RES0
for the purpose of the system-wide safe value. These bits will still be
sanity checked with strict match requirements, as is currently the case.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10 17:11:23 +00:00
Will Deacon
f31deaadff arm64: cpufeature: Don't enforce system-wide SPE capability
The statistical profiling extension (SPE) is an optional feature of
ARMv8.1 and is unlikely to be supported by all of the CPUs in a
heterogeneous system.

This patch updates the cpufeature checks so that such systems are not
tainted as unsupported.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10 14:28:01 +00:00
Will Deacon
b20d1ba3cf arm64: cpufeature: allow for version discrepancy in PMU implementations
Perf already supports multiple PMU instances for heterogeneous systems,
so there's no need to be strict in the cpufeature checking, particularly
as the PMU extension is optional in the architecture.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10 14:27:56 +00:00
James Morse
c8b06e3fdd arm64: Remove useless UAO IPI and describe how this gets enabled
Since its introduction, the UAO enable call was broken, and useless.
commit 2a6dcb2b5f ("arm64: cpufeature: Schedule enable() calls instead
of calling them via IPI"), fixed the framework so that these calls
are scheduled, so that they can modify PSTATE.

Now it is just useless. Remove it. UAO is enabled by the code patching
which causes get_user() and friends to use the 'ldtr' family of
instructions. This relies on the PSTATE.UAO bit being set to match
addr_limit, which we do in uao_thread_switch() called via __switch_to().

All that is needed to enable UAO is patch the code, and call schedule().
__apply_alternatives_multi_stop() calls stop_machine() when it modifies
the kernel text to enable the alternatives, (including the UAO code in
uao_thread_switch()). Once stop_machine() has finished __switch_to() is
called to reschedule the original task, this causes PSTATE.UAO to be set
appropriately. An explicit enable() call is not needed.

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
2017-01-10 12:38:06 +00:00
Catalin Marinas
4b65a5db36 arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1
This patch adds the uaccess macros/functions to disable access to user
space by setting TTBR0_EL1 to a reserved zeroed page. Since the value
written to TTBR0_EL1 must be a physical address, for simplicity this
patch introduces a reserved_ttbr0 page at a constant offset from
swapper_pg_dir. The uaccess_disable code uses the ttbr1_el1 value
adjusted by the reserved_ttbr0 offset.

Enabling access to user is done by restoring TTBR0_EL1 with the value
from the struct thread_info ttbr0 variable. Interrupts must be disabled
during the uaccess_ttbr0_enable code to ensure the atomicity of the
thread_info.ttbr0 read and TTBR0_EL1 write. This patch also moves the
get_thread_info asm macro from entry.S to assembler.h for reuse in the
uaccess_ttbr0_* macros.

Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-21 18:48:53 +00:00
Suzuki K Poulose
82e0191a1a arm64: Support systems without FP/ASIMD
The arm64 kernel assumes that FP/ASIMD units are always present
and accesses the FP/ASIMD specific registers unconditionally. This
could cause problems when they are absent. This patch adds the
support for kernel handling systems without FP/ASIMD by skipping the
register access within the kernel. For kvm, we trap the accesses
to FP/ASIMD and inject an undefined instruction exception to the VM.

The callers of the exported kernel_neon_begin_partial() should
make sure that the FP/ASIMD is supported.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: add comment on the ARM64_HAS_NO_FPSIMD conflict and the new location]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-16 18:05:10 +00:00
Suzuki K Poulose
a4023f6827 arm64: Add hypervisor safe helper for checking constant capabilities
The hypervisor may not have full access to the kernel data structures
and hence cannot safely use cpus_have_cap() helper for checking the
system capability. Add a safe helper for hypervisors to check a constant
system capability, which *doesn't* fall back to checking the bitmap
maintained by the kernel. With this, make the cpus_have_cap() only
check the bitmask and force constant cap checks to use the new API
for quicker checks.

Cc: Robert Ritcher <rritcher@cavium.com>
Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-16 17:50:51 +00:00
James Morse
2a6dcb2b5f arm64: cpufeature: Schedule enable() calls instead of calling them via IPI
The enable() call for a cpufeature/errata is called using on_each_cpu().
This issues a cross-call IPI to get the work done. Implicitly, this
stashes the running PSTATE in SPSR when the CPU receives the IPI, and
restores it when we return. This means an enable() call can never modify
PSTATE.

To allow PAN to do this, change the on_each_cpu() call to use
stop_machine(). This schedules the work on each CPU which allows
us to modify PSTATE.

This involves changing the protype of all the enable() functions.

enable_cpu_capabilities() is called during boot and enables the feature
on all online CPUs. This path now uses stop_machine(). CPU features for
hotplug'd CPUs are enabled by verify_local_cpu_features() which only
acts on the local CPU, and can already modify the running PSTATE as it
is called from secondary_start_kernel().

Reported-by: Tony Thompson <anthony.thompson@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20 09:50:53 +01:00
Suzuki K Poulose
c47a1900ad arm64: Rearrange CPU errata workaround checks
Right now we run through the work around checks on a CPU
from __cpuinfo_store_cpu. There are some problems with that:

1) We initialise the system wide CPU feature registers only after the
Boot CPU updates its cpuinfo. Now, if a work around depends on the
variance of a CPU ID feature (e.g, check for Cache Line size mismatch),
we have no way of performing it cleanly for the boot CPU.

2) It is out of place, invoked from __cpuinfo_store_cpu() in cpuinfo.c. It
is not an obvious place for that.

This patch rearranges the CPU specific capability(aka work around) checks.

1) At the moment we use verify_local_cpu_capabilities() to check if a new
CPU has all the system advertised features. Use this for the secondary CPUs
to perform the work around check. For that we rename
  verify_local_cpu_capabilities() => check_local_cpu_capabilities()
which:

   If the system wide capabilities haven't been initialised (i.e, the CPU
   is activated at the boot), update the system wide detected work arounds.

   Otherwise (i.e a CPU hotplugged in later) verify that this CPU conforms to the
   system wide capabilities.

2) Boot CPU updates the work arounds from smp_prepare_boot_cpu() after we have
initialised the system wide CPU feature values.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 15:03:28 +01:00
Suzuki K Poulose
89ba26458b arm64: Use consistent naming for errata handling
This is a cosmetic change to rename the functions dealing with
the errata work arounds to be more consistent with their naming.

1) check_local_cpu_errata() => update_cpu_errata_workarounds()
check_local_cpu_errata() actually updates the system's errata work
arounds. So rename it to reflect the same.

2) verify_local_cpu_errata() => verify_local_cpu_errata_workarounds()
Use errata_workarounds instead of _errata.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 15:03:28 +01:00
Suzuki K Poulose
ee7bc638f1 arm64: Set the safe value for L1 icache policy
Right now we use 0 as the safe value for CTR_EL0:L1Ip, which is
not defined at the moment. The safer value for the L1Ip should be
the weakest of the policies, which happens to be AIVIVT. While at it,
fix the comment about safe_val.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09 15:03:28 +01:00
Catalin Marinas
efd9e03fac arm64: Use static keys for CPU features
This patch adds static keys transparently for all the cpu_hwcaps
features by implementing an array of default-false static keys and
enabling them when detected. The cpus_have_cap() check uses the static
keys if the feature being checked is a constant, otherwise the compiler
generates the bitmap test.

Because of the early call to static_branch_enable() via
check_local_cpu_errata() -> update_cpu_capabilities(), the jump labels
are initialised in cpuinfo_store_boot_cpu().

Cc: Will Deacon <will.deacon@arm.com>
Cc: Suzuki K. Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-07 09:41:42 +01:00
Ard Biesheuvel
675b0563d6 arm64: cpufeature: expose arm64_ftr_reg struct for CTR_EL0
Expose the arm64_ftr_reg struct covering CTR_EL0 outside of cpufeature.o
so that other code can refer to it directly (i.e., without performing the
binary search)

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31 13:48:15 +01:00
Ard Biesheuvel
6f2b7eeff9 arm64: cpufeature: constify arm64_ftr_regs array
Constify the arm64_ftr_regs array, by moving the mutable arm64_ftr_reg
fields out of the array itself. This also streamlines the bsearch, since
the entire array can be covered by fewer cachelines. Moving the payload
out of the array also allows us to have special explicitly defined
struct instance in case other code needs to refer to it directly.

Note that this replaces the runtime sorting of the array with a runtime
BUG() check whether the array is sorted correctly in the code.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31 13:48:15 +01:00
Ard Biesheuvel
5e49d73c1d arm64: cpufeature: constify arm64_ftr_bits structures
The arm64_ftr_bits structures are never modified, so make them read-only.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31 13:48:15 +01:00
Linus Torvalds
221bb8a46e - ARM: GICv3 ITS emulation and various fixes. Removal of the old
VGIC implementation.
 
 - s390: support for trapping software breakpoints, nested virtualization
 (vSIE), the STHYI opcode, initial extensions for CPU model support.
 
 - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups,
 preliminary to this and the upcoming support for hardware virtualization
 extensions.
 
 - x86: support for execute-only mappings in nested EPT; reduced vmexit
 latency for TSC deadline timer (by about 30%) on Intel hosts; support for
 more than 255 vCPUs.
 
 - PPC: bugfixes.
 
 The ugly bit is the conflicts.  A couple of them are simple conflicts due
 to 4.7 fixes, but most of them are with other trees. There was definitely
 too much reliance on Acked-by here.  Some conflicts are for KVM patches
 where _I_ gave my Acked-by, but the worst are for this pull request's
 patches that touch files outside arch/*/kvm.  KVM submaintainers should
 probably learn to synchronize better with arch maintainers, with the
 latter providing topic branches whenever possible instead of Acked-by.
 This is what we do with arch/x86.  And I should learn to refuse pull
 requests when linux-next sends scary signals, even if that means that
 submaintainers have to rebase their branches.
 
 Anyhow, here's the list:
 
 - arch/x86/kvm/vmx.c: handle_pcommit and EXIT_REASON_PCOMMIT was removed
 by the nvdimm tree.  This tree adds handle_preemption_timer and
 EXIT_REASON_PREEMPTION_TIMER at the same place.  In general all mentions
 of pcommit have to go.
 
 There is also a conflict between a stable fix and this patch, where the
 stable fix removed the vmx_create_pml_buffer function and its call.
 
 - virt/kvm/kvm_main.c: kvm_cpu_notifier was removed by the hotplug tree.
 This tree adds kvm_io_bus_get_dev at the same place.
 
 - virt/kvm/arm/vgic.c: a few final bugfixes went into 4.7 before the
 file was completely removed for 4.8.
 
 - include/linux/irqchip/arm-gic-v3.h: this one is entirely our fault;
 this is a change that should have gone in through the irqchip tree and
 pulled by kvm-arm.  I think I would have rejected this kvm-arm pull
 request.  The KVM version is the right one, except that it lacks
 GITS_BASER_PAGES_SHIFT.
 
 - arch/powerpc: what a mess.  For the idle_book3s.S conflict, the KVM
 tree is the right one; everything else is trivial.  In this case I am
 not quite sure what went wrong.  The commit that is causing the mess
 (fd7bacbca4, "KVM: PPC: Book3S HV: Fix TB corruption in guest exit
 path on HMI interrupt", 2016-05-15) touches both arch/powerpc/kernel/
 and arch/powerpc/kvm/.  It's large, but at 396 insertions/5 deletions
 I guessed that it wasn't really possible to split it and that the 5
 deletions wouldn't conflict.  That wasn't the case.
 
 - arch/s390: also messy.  First is hypfs_diag.c where the KVM tree
 moved some code and the s390 tree patched it.  You have to reapply the
 relevant part of commits 6c22c98637, plus all of e030c1125e, to
 arch/s390/kernel/diag.c.  Or pick the linux-next conflict
 resolution from http://marc.info/?l=kvm&m=146717549531603&w=2.
 Second, there is a conflict in gmap.c between a stable fix and 4.8.
 The KVM version here is the correct one.
 
 I have pushed my resolution at refs/heads/merge-20160802 (commit
 3d1f53419842) at git://git.kernel.org/pub/scm/virt/kvm/kvm.git.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:

 - ARM: GICv3 ITS emulation and various fixes.  Removal of the
   old VGIC implementation.

 - s390: support for trapping software breakpoints, nested
   virtualization (vSIE), the STHYI opcode, initial extensions
   for CPU model support.

 - MIPS: support for MIPS64 hosts (32-bit guests only) and lots
   of cleanups, preliminary to this and the upcoming support for
   hardware virtualization extensions.

 - x86: support for execute-only mappings in nested EPT; reduced
   vmexit latency for TSC deadline timer (by about 30%) on Intel
   hosts; support for more than 255 vCPUs.

 - PPC: bugfixes.

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits)
  KVM: PPC: Introduce KVM_CAP_PPC_HTM
  MIPS: Select HAVE_KVM for MIPS64_R{2,6}
  MIPS: KVM: Reset CP0_PageMask during host TLB flush
  MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX()
  MIPS: KVM: Sign extend MFC0/RDHWR results
  MIPS: KVM: Fix 64-bit big endian dynamic translation
  MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase
  MIPS: KVM: Use 64-bit CP0_EBase when appropriate
  MIPS: KVM: Set CP0_Status.KX on MIPS64
  MIPS: KVM: Make entry code MIPS64 friendly
  MIPS: KVM: Use kmap instead of CKSEG0ADDR()
  MIPS: KVM: Use virt_to_phys() to get commpage PFN
  MIPS: Fix definition of KSEGX() for 64-bit
  KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD
  kvm: x86: nVMX: maintain internal copy of current VMCS
  KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE
  KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures
  KVM: arm64: vgic-its: Simplify MAPI error handling
  KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers
  KVM: arm64: vgic-its: Turn device_id validation into generic ID validation
  ...
2016-08-02 16:11:27 -04:00
Marc Zyngier
d174591016 arm64: KVM: Runtime detection of lower HYP offset
Add the code that enables the switch to the lower HYP VA range.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-07-03 23:41:27 +02:00
Andre Przywara
8e2318521b arm64: errata: Calling enable functions for CPU errata too
Currently we call the (optional) enable function for CPU _features_
only. As CPU _errata_ descriptions share the same data structure and
having an enable function is useful for errata as well (for instance
to set bits in SCTLR), lets call it when enumerating erratas too.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-07-01 11:30:28 +01:00
Suzuki K Poulose
6a6efbb45b arm64: Verify CPU errata work arounds on hotplugged CPU
CPU Errata work arounds are detected and applied to the
kernel code at boot time and the data is then freed up.
If a new hotplugged CPU requires a work around which
was not applied at boot time, there is nothing we can
do but simply fail the booting.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-25 15:14:03 +01:00
Marc Zyngier
e3661b128e arm64: Allow a capability to be checked on a single CPU
Now that the capabilities are only available once all the CPUs
have booted, we're unable to check for a particular feature
in any subsystem that gets initialized before then.

In order to support this, introduce a local_cpu_has_cap() function
that tests for the presence of a given capability independently
of the whole framework.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[ Added preemptible() check ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: remove duplicate initialisation of caps in this_cpu_has_cap]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-25 15:13:05 +01:00
Suzuki K Poulose
92406f0cc9 arm64: cpufeature: Add scope for capability check
Add scope parameter to the arm64_cpu_capabilities::matches(), so that
this can be reused for checking the capability on a given CPU vs the
system wide. The system uses the default scope associated with the
capability for initialising the CPU_HWCAPs and ELF_HWCAPs.

Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-25 15:12:21 +01:00
Suzuki K Poulose
643d703d2d arm64: compat: Check for AArch32 state
Make sure we have AArch32 state available for running COMPAT
binaries and also for switching the personality to PER_LINUX32.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
[ Added cap bit, checks for HWCAP, personality ]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20 12:22:42 +01:00
Suzuki K Poulose
042446a31e arm64: cpufeature: Track 32bit EL0 support
Add cpu_hwcap bit for keeping track of the support for 32bit EL0.

Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20 12:22:42 +01:00
Suzuki K Poulose
a6dc3cd718 arm64: cpufeature: Check availability of AArch32
On ARMv8 support for AArch32 state is optional. Hence it is
not safe to check the AArch32 ID registers for sanity, which
could lead to false warnings. This patch makes sure that the
AArch32 state is implemented before we keep track of the 32bit
ID registers.

As per ARM ARM (D.1.21.2 - Support for Exception Levels and
Execution States, DDI0487A.h), checking the support for AArch32
at EL0 is good enough to check the support for AArch32 (i.e,
AArch32 at EL1 => AArch32 at EL0, but not vice versa).

Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20 12:22:42 +01:00
Suzuki K Poulose
752835019c arm64: HWCAP: Split COMPAT HWCAP table entries
In order to handle systems which do not support 32bit at EL0,
split the COMPAT HWCAP entries into a separate table which can
be processed, only if the support is available.

Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20 12:22:42 +01:00
Suzuki K Poulose
f3efb67590 arm64: hwcaps: Cleanup naming
We use hwcaps for referring to ELF hwcaps capability information.
However this can be confusing with 'cpu_hwcaps' which stands for the
CPU capability bit field. This patch cleans up the names to make it
a bit more readable.

Tested-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20 12:22:41 +01:00
Suzuki K Poulose
ac1ad20f9e arm64: vhe: Verify CPU Exception Levels
With a VHE capable CPU, kernel can run at EL2 and is a decided at early
boot. If some of the CPUs didn't start it EL2 or doesn't have VHE, we
could have CPUs running at different exception levels, all in the same
kernel! This patch adds an early check for the secondary CPUs to detect
such situations.

For each non-boot CPU add a sanity check to make sure we don't have
different run levels w.r.t the boot CPU. We save the information on
whether the boot CPU is running in hyp mode or not and ensure the
remaining CPUs match it.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: made boot_cpu_hyp_mode static]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-15 18:06:07 +01:00
Kefeng Wang
7d7b4ae418 arm64: cpufeature: append additional id_aa64mmfr2 fields to cpufeature
There are some new cpu features which can be identified by id_aa64mmfr2,
this patch appends all fields of it.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-13 14:49:23 +01:00
Linus Torvalds
588ab3f9af arm64 updates for 4.6:
- Initial page table creation reworked to avoid breaking large block
   mappings (huge pages) into smaller ones. The ARM architecture requires
   break-before-make in such cases to avoid TLB conflicts but that's not
   always possible on live page tables
 
 - Kernel virtual memory layout: the kernel image is no longer linked to
   the bottom of the linear mapping (PAGE_OFFSET) but at the bottom of
   the vmalloc space, allowing the kernel to be loaded (nearly) anywhere
   in physical RAM
 
 - Kernel ASLR: position independent kernel Image and modules being
   randomly mapped in the vmalloc space with the randomness is provided
   by UEFI (efi_get_random_bytes() patches merged via the arm64 tree,
   acked by Matt Fleming)
 
 - Implement relative exception tables for arm64, required by KASLR
   (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c but
   actual x86 conversion to deferred to 4.7 because of the merge
   dependencies)
 
 - Support for the User Access Override feature of ARMv8.2: this allows
   uaccess functions (get_user etc.) to be implemented using LDTR/STTR
   instructions. Such instructions, when run by the kernel, perform
   unprivileged accesses adding an extra level of protection. The
   set_fs() macro is used to "upgrade" such instruction to privileged
   accesses via the UAO bit
 
 - Half-precision floating point support (part of ARMv8.2)
 
 - Optimisations for CPUs with or without a hardware prefetcher (using
   run-time code patching)
 
 - copy_page performance improvement to deal with 128 bytes at a time
 
 - Sanity checks on the CPU capabilities (via CPUID) to prevent
   incompatible secondary CPUs from being brought up (e.g. weird
   big.LITTLE configurations)
 
 - valid_user_regs() reworked for better sanity check of the sigcontext
   information (restored pstate information)
 
 - ACPI parking protocol implementation
 
 - CONFIG_DEBUG_RODATA enabled by default
 
 - VDSO code marked as read-only
 
 - DEBUG_PAGEALLOC support
 
 - ARCH_HAS_UBSAN_SANITIZE_ALL enabled
 
 - Erratum workaround Cavium ThunderX SoC
 
 - set_pte_at() fix for PROT_NONE mappings
 
 - Code clean-ups
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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:
 "Here are the main arm64 updates for 4.6.  There are some relatively
  intrusive changes to support KASLR, the reworking of the kernel
  virtual memory layout and initial page table creation.

  Summary:

   - Initial page table creation reworked to avoid breaking large block
     mappings (huge pages) into smaller ones.  The ARM architecture
     requires break-before-make in such cases to avoid TLB conflicts but
     that's not always possible on live page tables

   - Kernel virtual memory layout: the kernel image is no longer linked
     to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom
     of the vmalloc space, allowing the kernel to be loaded (nearly)
     anywhere in physical RAM

   - Kernel ASLR: position independent kernel Image and modules being
     randomly mapped in the vmalloc space with the randomness is
     provided by UEFI (efi_get_random_bytes() patches merged via the
     arm64 tree, acked by Matt Fleming)

   - Implement relative exception tables for arm64, required by KASLR
     (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c
     but actual x86 conversion to deferred to 4.7 because of the merge
     dependencies)

   - Support for the User Access Override feature of ARMv8.2: this
     allows uaccess functions (get_user etc.) to be implemented using
     LDTR/STTR instructions.  Such instructions, when run by the kernel,
     perform unprivileged accesses adding an extra level of protection.
     The set_fs() macro is used to "upgrade" such instruction to
     privileged accesses via the UAO bit

   - Half-precision floating point support (part of ARMv8.2)

   - Optimisations for CPUs with or without a hardware prefetcher (using
     run-time code patching)

   - copy_page performance improvement to deal with 128 bytes at a time

   - Sanity checks on the CPU capabilities (via CPUID) to prevent
     incompatible secondary CPUs from being brought up (e.g.  weird
     big.LITTLE configurations)

   - valid_user_regs() reworked for better sanity check of the
     sigcontext information (restored pstate information)

   - ACPI parking protocol implementation

   - CONFIG_DEBUG_RODATA enabled by default

   - VDSO code marked as read-only

   - DEBUG_PAGEALLOC support

   - ARCH_HAS_UBSAN_SANITIZE_ALL enabled

   - Erratum workaround Cavium ThunderX SoC

   - set_pte_at() fix for PROT_NONE mappings

   - Code clean-ups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits)
  arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
  arm64: kasan: Use actual memory node when populating the kernel image shadow
  arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission
  arm64: Fix misspellings in comments.
  arm64: efi: add missing frame pointer assignment
  arm64: make mrs_s prefixing implicit in read_cpuid
  arm64: enable CONFIG_DEBUG_RODATA by default
  arm64: Rework valid_user_regs
  arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
  arm64: KVM: Move kvm_call_hyp back to its original localtion
  arm64: mm: treat memstart_addr as a signed quantity
  arm64: mm: list kernel sections in order
  arm64: lse: deal with clobbered IP registers after branch via PLT
  arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR
  arm64: kconfig: add submenu for 8.2 architectural features
  arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot
  arm64: Add support for Half precision floating point
  arm64: Remove fixmap include fragility
  arm64: Add workaround for Cavium erratum 27456
  arm64: mm: Mark .rodata as RO
  ...
2016-03-17 20:03:47 -07:00
Mark Rutland
1cc6ed90dd arm64: make mrs_s prefixing implicit in read_cpuid
Commit 0f54b14e76 ("arm64: cpufeature: Change read_cpuid() to use
sysreg's mrs_s macro") changed read_cpuid to require a SYS_ prefix on
register names, to allow manual assembly of registers unknown by the
toolchain, using tables in sysreg.h.

This interacts poorly with commit 42b5573403 ("efi/arm64: Check
for h/w support before booting a >4 KB granular kernel"), which is
curretly queued via the tip tree, and uses read_cpuid without a SYS_
prefix. Due to this, a build of next-20160304 fails if EFI and 64K pages
are selected.

To avoid this issue when trees are merged, move the required SYS_
prefixing into read_cpuid, and revert all of the updated callsites to
pass plain register names. This effectively reverts the bulk of commit
0f54b14e76.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-03-04 14:12:46 +00:00
Marc Zyngier
d88701bea3 arm64: Add ARM64_HAS_VIRT_HOST_EXTN feature
Add a new ARM64_HAS_VIRT_HOST_EXTN features to indicate that the
CPU has the ARMv8.1 VHE capability.

This will be used to trigger kernel patching in KVM.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Suzuki K Poulose
bf50061844 arm64: Add support for Half precision floating point
ARMv8.2 extensions [1] include an optional feature, which supports
half precision(16bit) floating point/asimd data processing
instructions. This patch adds support for detecting and exposing
the same to the userspace via HWCAPs

[1] https://community.arm.com/groups/processors/blog/2016/01/05/armv8-a-architecture-evolution

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-26 15:37:01 +00:00
Suzuki K Poulose
28c5dcb22f arm64: Rename cpuid_feature field extract routines
Now that we have a clear understanding of the sign of a feature,
rename the routines to reflect the sign, so that it is not misused.
The cpuid_feature_extract_field() now accepts a 'sign' parameter.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:08 +00:00
Suzuki K Poulose
ff96f7bc7b arm64: capabilities: Handle sign of the feature bit
Use the appropriate accessor for the feature bit by keeping
track of the sign of the feature

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:07 +00:00
Suzuki K Poulose
0710cfdb8d arm64: cpufeature: Fix the sign of feature bits
There is a confusion on whether the values of a feature are signed
or not in ARM. This is not clearly mentioned in the ARM ARM either.
We have dealt most of the bits as signed so far, and marked the
rest as unsigned explicitly. This fixed in ARM ARM and will be rolled
out soon.

Here is the criteria in a nutshell:

1) The fields, which are either signed or unsigned, use increasing
   numerical values to indicate an increase in functionality. Thus, if a value
   of 0x1 indicates the presence of some instructions, then the 0x2 value will
   indicate the presence of those instructions plus some additional instructions
   or functionality.

2) For ID field values where the value 0x0 defines that a feature is not present,
   the number is an unsigned value.

3) For some features where the feature was made optional or removed after the
   start of the definition of the architecture, the value 0x0 is used to
   indicate the presence of a feature, and 0xF indicates the absence of the
   feature. In these cases, the fields are, in effect, holding signed values.

So with these rules applied, we have only the following fields which are signed and
the rest are unsigned.

 a) ID_AA64PFR0_EL1: {FP, ASIMD}
 b) ID_AA64MMFR0_EL1: {TGran4K, TGran64K}
 c) ID_AA64DFR0_EL1: PMUVer (0xf - PMUv3 not implemented)
 d) ID_DFR0_EL1: PerfMon
 e) ID_MMFR0_EL1: {InnerShr, OuterShr}

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:07 +00:00
Suzuki K Poulose
e53435031a arm64: cpufeature: Correct feature register tables
Correct the feature bit entries for :
  ID_DFR0
  ID_MMFR0

to fix the default safe value for some of the bits.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:07 +00:00
Suzuki K Poulose
13f417f3b8 arm64: Ensure the secondary CPUs have safe ASIDBits size
Adds a hook for checking whether a secondary CPU has the
features used already by the kernel during early boot, based
on the boot CPU and plugs in the check for ASID size.

The ID_AA64MMFR0_EL1:ASIDBits determines the size of the mm context
id and is used in the early boot to make decisions. The value is
picked up from the Boot CPU and cannot be delayed until other CPUs
are up. If a secondary CPU has a smaller size than that of the Boot
CPU, things will break horribly and the usual SANITY check is not good
enough to prevent the system from crashing. So, crash the system with
enough information.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:06 +00:00
Suzuki K Poulose
fd9c2790cb arm64: Enable CPU capability verification unconditionally
We verify the capabilities of the secondary CPUs only when
hotplug is enabled. The boot time activated CPUs do not
go through the verification by checking whether the system
wide capabilities were initialised or not.

This patch removes the capability check dependency on CONFIG_HOTPLUG_CPU,
to make sure that all the secondary CPUs go through the check.
The boot time activated CPUs will still skip the system wide
capability check. The plan is to hook in a check for CPU features
used by the kernel at early boot up, based on the Boot CPU values.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:06 +00:00
Suzuki K Poulose
fce6361fe9 arm64: Move cpu_die_early to smp.c
This patch moves cpu_die_early to smp.c, where it fits better.
No functional changes, except for adding the necessary checks
for CONFIG_HOTPLUG_CPU.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:45 +00:00
Suzuki K Poulose
ee02a15919 arm64: Introduce cpu_die_early
Or in other words, make fail_incapable_cpu() reusable.

We use fail_incapable_cpu() to kill a secondary CPU early during the
bringup, which doesn't have the system advertised capabilities.
This patch makes the routine more generic, to kill a secondary
booting CPU, getting rid of the dependency on capability struct.
This can be used by checks which are not necessarily attached to
a capability struct (e.g, cpu ASIDBits).

In that process, renames the function to cpu_die_early() to better
match its functionality. This will be moved to arch/arm64/kernel/smp.c
later.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:44 +00:00
Suzuki K Poulose
c4bc34d202 arm64: Add a helper for parking CPUs in a loop
Adds a routine which can be used to park CPUs (spinning in kernel)
when they can't be killed.

Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24 17:17:44 +00:00
James Morse
7054419600 arm64: kernel: Don't toggle PAN on systems with UAO
If a CPU supports both Privileged Access Never (PAN) and User Access
Override (UAO), we don't need to disable/re-enable PAN round all
copy_to_user() like calls.

UAO alternatives cause these calls to use the 'unprivileged' load/store
instructions, which are overridden to be the privileged kind when
fs==KERNEL_DS.

This patch changes the copy_to_user() calls to have their PAN toggling
depend on a new composite 'feature' ARM64_ALT_PAN_NOT_UAO.

If both features are detected, PAN will be enabled, but the copy_to_user()
alternatives will not be applied. This means PAN will be enabled all the
time for these functions. If only PAN is detected, the toggling will be
enabled as normal.

This will save the time taken to disable/re-enable PAN, and allow us to
catch copy_to_user() accesses that occur with fs==KERNEL_DS.

Futex and swp-emulation code continue to hang their PAN toggling code on
ARM64_HAS_PAN.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:05 +00:00
James Morse
644c2ae198 arm64: cpufeature: Test 'matches' pointer to find the end of the list
CPU feature code uses the desc field as a test to find the end of the list,
this means every entry must have a description. This generates noise for
entries in the list that aren't really features, but combinations of them.
e.g.
> CPU features: detected feature: Privileged Access Never
> CPU features: detected feature: PAN and not UAO

These combination features are needed for corner cases with alternatives,
where cpu features interact.

Change all walkers of the arm64_features[] and arm64_hwcaps[] lists to test
'matches' not 'desc', and only print 'desc' if it is non-NULL.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:05 +00:00
James Morse
57f4959bad arm64: kernel: Add support for User Access Override
'User Access Override' is a new ARMv8.2 feature which allows the
unprivileged load and store instructions to be overridden to behave in
the normal way.

This patch converts {get,put}_user() and friends to use ldtr*/sttr*
instructions - so that they can only access EL0 memory, then enables
UAO when fs==KERNEL_DS so that these functions can access kernel memory.

This allows user space's read/write permissions to be checked against the
page tables, instead of testing addr<USER_DS, then using the kernel's
read/write permissions.

Signed-off-by: James Morse <james.morse@arm.com>
[catalin.marinas@arm.com: move uao_thread_switch() above dsb()]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 17:27:04 +00:00
James Morse
406e308770 arm64: add ARMv8.2 id_aa64mmfr2 boiler plate
ARMv8.2 adds a new feature register id_aa64mmfr2. This patch adds the
cpu feature boiler plate used by the actual features in later patches.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 12:00:01 +00:00
James Morse
0f54b14e76 arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro
Older assemblers may not have support for newer feature registers. To get
round this, sysreg.h provides a 'mrs_s' macro that takes a register
encoding and generates the raw instruction.

Change read_cpuid() to use mrs_s in all cases so that new registers
don't have to be a special case. Including sysreg.h means we need to move
the include and definition of read_cpuid() after the #ifndef __ASSEMBLY__
to avoid syntax errors in vmlinux.lds.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 11:59:54 +00:00
Will Deacon
d5370f7548 arm64: prefetch: add alternative pattern for CPUs without a prefetcher
Most CPUs have a hardware prefetcher which generally performs better
without explicit prefetch instructions issued by software, however
some CPUs (e.g. Cavium ThunderX) rely solely on explicit prefetch
instructions.

This patch adds an alternative pattern (ARM64_HAS_NO_HW_PREFETCH) to
allow our library code to make use of explicit prefetch instructions
during things like copy routines only when the CPU does not have the
capability to perform the prefetching itself.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Andrew Pinski <apinski@cavium.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 15:12:32 +00:00
Jisheng Zhang
a7c61a3452 arm64: add __init/__initdata section marker to some functions/variables
These functions/variables are not needed after booting, so mark them
as __init or __initdata.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-02 12:17:11 +00:00
Suzuki K. Poulose
4f0a606bce arm64: cpufeature: Track unsigned fields
Some of the feature bits have unsigned values and need
to be treated accordingly to avoid errors. Adds the property
to the feature bits and use the appropriate field extract helpers.

Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26 18:07:59 +00:00
Linus Torvalds
a18e2fa5e6 arm64 fixes and clean-ups:
- __cmpxchg_double*() return type fix to avoid truncation of a long to
   int and subsequent logical "not" in cmpxchg_double() misinterpreting
   the operation success/failure
 - BPF fixes for mod and div by zero
 - Fix compilation with STRICT_MM_TYPECHECKS enabled
 - VDSO build fix without libgcov
 - Some static and __maybe_unused annotations
 - Kconfig clean-up (FRAME_POINTER)
 - defconfig update for CRYPTO_CRC32_ARM64
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes and clean-ups from Catalin Marinas:
 "Here's a second pull request for this merging window with some
  fixes/clean-ups:

   - __cmpxchg_double*() return type fix to avoid truncation of a long
     to int and subsequent logical "not" in cmpxchg_double()
     misinterpreting the operation success/failure

   - BPF fixes for mod and div by zero

   - Fix compilation with STRICT_MM_TYPECHECKS enabled

   - VDSO build fix without libgcov

   - Some static and __maybe_unused annotations

   - Kconfig clean-up (FRAME_POINTER)

   - defconfig update for CRYPTO_CRC32_ARM64"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: suspend: make hw_breakpoint_restore static
  arm64: mmu: make split_pud and fixup_executable static
  arm64: smp: make of_parse_and_init_cpus static
  arm64: use linux/types.h in kvm.h
  arm64: build vdso without libgcov
  arm64: mark cpus_have_hwcap as __maybe_unused
  arm64: remove redundant FRAME_POINTER kconfig option and force to select it
  arm64: fix R/O permissions of FDT mapping
  arm64: fix STRICT_MM_TYPECHECKS issue in PTE_CONT manipulation
  arm64: bpf: fix mod-by-zero case
  arm64: bpf: fix div-by-zero case
  arm64: Enable CRYPTO_CRC32_ARM64 in defconfig
  arm64: cmpxchg_dbl: fix return value type
2015-11-12 15:33:11 -08:00
Arnd Bergmann
3d6d103538 arm64: mark cpus_have_hwcap as __maybe_unused
cpus_have_hwcap() is defined as a 'static' function an only used in
one place that is inside of an #ifdef, so we get a warning when
the only user is disabled:

arch/arm64/kernel/cpufeature.c:699:13: warning: 'cpus_have_hwcap' defined but not used [-Wunused-function]

This marks the function as __maybe_unused, so the compiler knows that
it can drop the function definition without warning about it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 37b01d53ce ("arm64/HWCAP: Use system wide safe values")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-12 15:18:01 +00:00
Linus Torvalds
2dc10ad81f arm64 updates for 4.4:
- "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree
 
 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features. The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)
 
 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT
 
 - Implement native {relaxed, acquire, release} atomics for arm64
 
 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)
 
 - KASan support for arm64
 
 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)
 
 - copy_{to,from,in}_user optimisations (sharing the memcpy template)
 
 - perf: moving arm64 to the arm32/64 shared PMU framework
 
 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware
 
 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)
 
 - Generic CONFIG_HZ now used on arm64
 
 - defconfig updates
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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:

 - "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree

 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features.  The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)

 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT

 - Implement native {relaxed, acquire, release} atomics for arm64

 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)

 - KASan support for arm64

 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)

 - copy_{to,from,in}_user optimisations (sharing the memcpy template)

 - perf: moving arm64 to the arm32/64 shared PMU framework

 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware

 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)

 - Generic CONFIG_HZ now used on arm64

 - defconfig updates

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits)
  arm64/efi: fix libstub build under CONFIG_MODVERSIONS
  ARM64: Enable multi-core scheduler support by default
  arm64/efi: move arm64 specific stub C code to libstub
  arm64: page-align sections for DEBUG_RODATA
  arm64: Fix build with CONFIG_ZONE_DMA=n
  arm64: Fix compat register mappings
  arm64: Increase the max granular size
  arm64: remove bogus TASK_SIZE_64 check
  arm64: make Timer Interrupt Frequency selectable
  arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED
  arm64: cachetype: fix definitions of ICACHEF_* flags
  arm64: cpufeature: declare enable_cpu_capabilities as static
  genirq: Make the cpuhotplug migration code less noisy
  arm64: Constify hwcap name string arrays
  arm64/kvm: Make use of the system wide safe values
  arm64/debug: Make use of the system wide safe value
  arm64: Move FP/ASIMD hwcap handling to common code
  arm64/HWCAP: Use system wide safe values
  arm64/capabilities: Make use of system wide safe value
  arm64: Delay cpu feature capability checks
  ...
2015-11-04 14:47:13 -08:00
Will Deacon
fde4a59fc1 arm64: cpufeature: declare enable_cpu_capabilities as static
enable_cpu_capabilities is only called from within cpufeature.c, so it
can be declared static.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-28 18:31:49 +00:00
Suzuki K. Poulose
fe80f9f2da arm64: Move FP/ASIMD hwcap handling to common code
The FP/ASIMD is detected in fpsimd_init(), which is built-in
unconditionally. Lets move the hwcap handling to the central place.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:59 +01:00
Suzuki K. Poulose
37b01d53ce arm64/HWCAP: Use system wide safe values
Extend struct arm64_cpu_capabilities to handle the HWCAP detection
and make use of the system wide value of the feature registers for
a reliable set of HWCAPs.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:58 +01:00
Suzuki K. Poulose
da8d02d19f arm64/capabilities: Make use of system wide safe value
Now that we can reliably read the system wide safe value for a
feature register, use that to compute the system capability.
This patch also replaces the 'feature-register-specific'
methods with a generic routine to check the capability.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:58 +01:00
Suzuki K. Poulose
dbb4e152b8 arm64: Delay cpu feature capability checks
At the moment we run through the arm64_features capability list for
each CPU and set the capability if one of the CPU supports it. This
could be problematic in a heterogeneous system with differing capabilities.
Delay the CPU feature checks until all the enabled CPUs are up(i.e,
smp_cpus_done(), so that we can make better decisions based on the
overall system capability. Once we decide and advertise the capabilities
the alternatives can be applied. From this state, we cannot roll back
a feature to disabled based on the values from a new hotplugged CPU,
due to the runtime patching and other reasons. So, for all new CPUs,
we need to make sure that they have the established system capabilities.
Failing which, we bring the CPU down, preventing it from turning online.
Once the capabilities are decided, any new CPU booting up goes through
verification to ensure that it has all the enabled capabilities and also
invokes the respective enable() method on the CPU.

The CPU errata checks are not delayed and is still executed per-CPU
to detect the respective capabilities. If we ever come across a non-errata
capability that needs to be checked on each-CPU, we could introduce them via
a new capability table(or introduce a flag), which can be processed per CPU.

The next patch will make the feature checks use the system wide
safe value of a feature register.

NOTE: The enable() methods associated with the capability is scheduled
on all the CPUs (which is the only use case at the moment). If we need
a different type of 'enable()' which only needs to be run once on any CPU,
we should be able to handle that when needed.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
[catalin.marinas@arm.com: static variable and coding style fixes]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:58 +01:00
Suzuki K. Poulose
ce8b602c69 arm64: Refactor check_cpu_capabilities
check_cpu_capabilities runs through a given list of caps and
checks if the system has the cap, updates the system capability
bitmap and also runs any enable() methods associated with them.
All of this is not quite obvious from the name 'check'. This
patch splits the check_cpu_capabilities into two parts :

1) update_cpu_capabilities
 => Runs through the given list and updates the system
    wide capability map.
2) enable_cpu_capabilities
 => Runs through the given list and invokes enable() (if any)
    for the caps enabled on the system.

Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Suggested-by: Catalin Marinas <catalin.marinsa@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:57 +01:00
Suzuki K. Poulose
c1e8656cba arm64: Cleanup mixed endian support detection
Make use of the system wide safe register to decide the support
for mixed endian.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:57 +01:00
Suzuki K. Poulose
b3f1537893 arm64: Read system wide CPUID value
Add an API for reading the safe CPUID value across the
system from the new infrastructure.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:56 +01:00
Suzuki K. Poulose
3086d391f9 arm64: Consolidate CPU Sanity check to CPU Feature infrastructure
This patch consolidates the CPU Sanity check to the new infrastructure.

Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:56 +01:00
Suzuki K. Poulose
3c739b5710 arm64: Keep track of CPU feature registers
This patch adds an infrastructure to keep track of the CPU feature
registers on the system. For each register, the infrastructure keeps
track of the system wide safe value of the feature bits. Also, tracks
the which fields of a register should be matched strictly across all
the CPUs on the system for the SANITY check infrastructure.

The feature bits are classified into following 3 types depending on
the implication of the possible values. This information is used to
decide the safe value for a feature.

LOWER_SAFE  - The smaller value is safer
HIGHER_SAFE - The bigger value is safer
EXACT       - We can't decide between the two, so a predefined safe_value is used.

This infrastructure will be later used to make better decisions for:

 - Kernel features (e.g, KVM, Debug)
 - SANITY Check
 - CPU capability
 - ELF HWCAP
 - Exposing CPU Feature register to userspace.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
[catalin.marinas@arm.com: whitespace fix]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:35:37 +01:00
Suzuki K. Poulose
cdcf817b7e arm64: Move mixed endian support detection
Move the mixed endian support detection code to cpufeature.c
from cpuinfo.c. This also moves the update_cpu_features()
used by mixed endian detection code, which will get more
functionality.

Also moves the ID register field shifts to asm/sysreg.h,
where all the useful definitions will end up in later patches.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:33:51 +01:00
Suzuki K. Poulose
9cdf8ec4a8 arm64: Move cpu feature detection code
This patch moves the CPU feature detection code from
 arch/arm64/kernel/{setup.c to cpufeature.c}

The plan is to consolidate all the CPU feature handling
in cpufeature.c.

Apart from changing pr_fmt from "alternatives" to "cpu features",
there are no functional changes.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Tested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21 15:33:46 +01:00
Marc Zyngier
963fcd4095 arm64: cpufeatures: Check ICC_EL1_SRE.SRE before enabling ARM64_HAS_SYSREG_GIC_CPUIF
As the firmware (or the hypervisor) may have disabled SRE access,
check that SRE can actually be enabled before declaring that we
do have that capability.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-10-09 22:16:54 +01:00
Will Deacon
2e94da1379 arm64: lse: use generic cpufeature detection for LSE atomics
Rework the cpufeature detection to support ISAR0 and use that for
detecting the presence of LSE atomics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 16:37:14 +01:00
James Morse
338d4f49d6 arm64: kernel: Add support for Privileged Access Never
'Privileged Access Never' is a new arm8.1 feature which prevents
privileged code from accessing any virtual address where read or write
access is also permitted at EL0.

This patch enables the PAN feature on all CPUs, and modifies {get,put}_user
helpers temporarily to permit access.

This will catch kernel bugs where user memory is accessed directly.
'Unprivileged loads and stores' using ldtrb et al are unaffected by PAN.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
[will: use ALTERNATIVE in asm and tidy up pan_enable check]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:41 +01:00
James Morse
18ffa046c5 arm64: kernel: Add min_field_value and use '>=' for feature detection
When a new cpu feature is available, the cpu feature bits will have some
initial value, which is incremented when the feature is updated.
This patch changes 'register_value' to be 'min_field_value', and checks
the feature bits value (interpreted as a signed int) is greater than this
minimum.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:41 +01:00
James Morse
1c0763037f arm64: kernel: Add cpufeature 'enable' callback
This patch adds an 'enable()' callback to cpu capability/feature
detection, allowing features that require some setup or configuration
to get this opportunity once the feature has been detected.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:41 +01:00
Marc Zyngier
94a9e04aa1 arm64: alternative: Introduce feature for GICv3 CPU interface
Add a new item to the feature set (ARM64_HAS_SYSREG_GIC_CPUIF)
to indicate that we have a system register GIC CPU interface

This will help KVM switching to alternative instruction patching.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-06-12 15:11:50 +01:00
Marc Zyngier
359b706473 arm64: Extract feature parsing code from cpu_errata.c
As we detect more architectural features at runtime, it makes
sense to reuse the existing framework whilst avoiding to call
a feature an erratum...

This patch extract the core capability parsing, moves it into
a new file (cpufeature.c), and let the CPU errata detection code
use it.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-30 11:03:43 +01:00