Commit Graph

12127 Commits

Author SHA1 Message Date
Linus Torvalds
e279160f49 The timekeeping and timers departement provides:
- Time namespace support:
 
     If a container migrates from one host to another then it expects that
     clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime these
     clocks can differ significantly on two hosts, in the worst case time
     goes backwards which is a violation of the POSIX requirements.
 
     The time namespace addresses this problem. It allows to set offsets for
     clock MONOTONIC and BOOTTIME once after creation and before tasks are
     associated with the namespace. These offsets are taken into account by
     timers and timekeeping including the VDSO.
 
     Offsets for wall clock based clocks (REALTIME/TAI) are not provided by
     this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric potential
     use cases which were discussed at Plumbers '18.
 
     The overhead for tasks in the root namespace (host time offsets = 0) is
     in the noise and great effort was made to ensure that especially in the
     VDSO. If time namespace is disabled in the kernel configuration the
     code is compiled out.
 
     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this feature
     and kept on for more than a year addressing review comments, finding
     better solutions. A pleasant experience.
 
   - Overhaul of the alarmtimer device dependency handling to ensure that
     the init/suspend/resume ordering is correct.
 
   - A new clocksource/event driver for Microchip PIT64
 
   - Suspend/resume support for the Hyper-V clocksource
 
   - The usual pile of fixes, updates and improvements mostly in the
     driver code.
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Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The timekeeping and timers departement provides:

   - Time namespace support:

     If a container migrates from one host to another then it expects
     that clocks based on MONOTONIC and BOOTTIME are not subject to
     disruption. Due to different boot time and non-suspended runtime
     these clocks can differ significantly on two hosts, in the worst
     case time goes backwards which is a violation of the POSIX
     requirements.

     The time namespace addresses this problem. It allows to set offsets
     for clock MONOTONIC and BOOTTIME once after creation and before
     tasks are associated with the namespace. These offsets are taken
     into account by timers and timekeeping including the VDSO.

     Offsets for wall clock based clocks (REALTIME/TAI) are not provided
     by this mechanism. While in theory possible, the overhead and code
     complexity would be immense and not justified by the esoteric
     potential use cases which were discussed at Plumbers '18.

     The overhead for tasks in the root namespace (ie where host time
     offsets = 0) is in the noise and great effort was made to ensure
     that especially in the VDSO. If time namespace is disabled in the
     kernel configuration the code is compiled out.

     Kudos to Andrei Vagin and Dmitry Sofanov who implemented this
     feature and kept on for more than a year addressing review
     comments, finding better solutions. A pleasant experience.

   - Overhaul of the alarmtimer device dependency handling to ensure
     that the init/suspend/resume ordering is correct.

   - A new clocksource/event driver for Microchip PIT64

   - Suspend/resume support for the Hyper-V clocksource

   - The usual pile of fixes, updates and improvements mostly in the
     driver code"

* tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
  alarmtimer: Use wakeup source from alarmtimer platform device
  alarmtimer: Make alarmtimer platform device child of RTC device
  alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
  hrtimer: Add missing sparse annotation for __run_timer()
  lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres()
  MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel
  clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC
  clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
  clocksource/drivers/timer-microchip-pit64b: Fix sparse warning
  clocksource/drivers/exynos_mct: Rename Exynos to lowercase
  clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access
  clocksource/drivers/timer-ti-dm: Switch to platform_get_irq
  clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource
  clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe
  clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource
  clocksource/drivers/bcm2835_timer: Fix memory leak of timer
  clocksource/drivers/cadence-ttc: Use ttc driver as platform driver
  clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support
  clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page
  ...
2020-01-27 16:47:05 -08:00
Linus Torvalds
0238d3c753 arm64 updates for 5.6
- New architecture features
 	* Support for Armv8.5 E0PD, which benefits KASLR in the same way as
 	  KPTI but without the overhead. This allows KPTI to be disabled on
 	  CPUs that are not affected by Meltdown, even is KASLR is enabled.
 
 	* Initial support for the Armv8.5 RNG instructions, which claim to
 	  provide access to a high bandwidth, cryptographically secure hardware
 	  random number generator. As well as exposing these to userspace, we
 	  also use them as part of the KASLR seed and to seed the crng once
 	  all CPUs have come online.
 
 	* Advertise a bunch of new instructions to userspace, including support
 	  for Data Gathering Hint, Matrix Multiply and 16-bit floating point.
 
 - Kexec
 	* Cleanups in preparation for relocating with the MMU enabled
 	* Support for loading crash dump kernels with kexec_file_load()
 
 - Perf and PMU drivers
 	* Cleanups and non-critical fixes for a couple of system PMU drivers
 
 - FPU-less (aka broken) CPU support
 	* Considerable fixes to support CPUs without the FP/SIMD extensions,
 	  including their presence in heterogeneous systems. Good luck finding
 	  a 64-bit userspace that handles this.
 
 - Modern assembly function annotations
 	* Start migrating our use of ENTRY() and ENDPROC() over to the
 	  new-fangled SYM_{CODE,FUNC}_{START,END} macros, which are intended to
 	  aid debuggers
 
 - Kbuild
 	* Cleanup detection of LSE support in the assembler by introducing
 	  'as-instr'
 
 	* Remove compressed Image files when building clean targets
 
 - IP checksumming
 	* Implement optimised IPv4 checksumming routine when hardware offload
 	  is not in use. An IPv6 version is in the works, pending testing.
 
 - Hardware errata
 	* Work around Cortex-A55 erratum #1530923
 
 - Shadow call stack
 	* Work around some issues with Clang's integrated assembler not liking
 	  our perfectly reasonable assembly code
 
 	* Avoid allocating the X18 register, so that it can be used to hold the
 	  shadow call stack pointer in future
 
 - ACPI
 	* Fix ID count checking in IORT code. This may regress broken firmware
 	  that happened to work with the old implementation, in which case we'll
 	  have to revert it and try something else
 
 	* Fix DAIF corruption on return from GHES handler with pseudo-NMIs
 
 - Miscellaneous
 	* Whitelist some CPUs that are unaffected by Spectre-v2
 
 	* Reduce frequency of ASID rollover when KPTI is compiled in but
 	  inactive
 
 	* Reserve a couple of arch-specific PROT flags that are already used by
 	  Sparc and PowerPC and are planned for later use with BTI on arm64
 
 	* Preparatory cleanup of our entry assembly code in preparation for
 	  moving more of it into C later on
 
 	* Refactoring and cleanup
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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 changes are a real mixed bag this time around.

  The only scary looking one from the diffstat is the uapi change to
  asm-generic/mman-common.h, but this has been acked by Arnd and is
  actually just adding a pair of comments in an attempt to prevent
  allocation of some PROT values which tend to get used for
  arch-specific purposes. We'll be using them for Branch Target
  Identification (a CFI-like hardening feature), which is currently
  under review on the mailing list.

  New architecture features:

   - Support for Armv8.5 E0PD, which benefits KASLR in the same way as
     KPTI but without the overhead. This allows KPTI to be disabled on
     CPUs that are not affected by Meltdown, even is KASLR is enabled.

   - Initial support for the Armv8.5 RNG instructions, which claim to
     provide access to a high bandwidth, cryptographically secure
     hardware random number generator. As well as exposing these to
     userspace, we also use them as part of the KASLR seed and to seed
     the crng once all CPUs have come online.

   - Advertise a bunch of new instructions to userspace, including
     support for Data Gathering Hint, Matrix Multiply and 16-bit
     floating point.

  Kexec:

   - Cleanups in preparation for relocating with the MMU enabled

   - Support for loading crash dump kernels with kexec_file_load()

  Perf and PMU drivers:

   - Cleanups and non-critical fixes for a couple of system PMU drivers

  FPU-less (aka broken) CPU support:

   - Considerable fixes to support CPUs without the FP/SIMD extensions,
     including their presence in heterogeneous systems. Good luck
     finding a 64-bit userspace that handles this.

  Modern assembly function annotations:

   - Start migrating our use of ENTRY() and ENDPROC() over to the
     new-fangled SYM_{CODE,FUNC}_{START,END} macros, which are intended
     to aid debuggers

  Kbuild:

   - Cleanup detection of LSE support in the assembler by introducing
     'as-instr'

   - Remove compressed Image files when building clean targets

  IP checksumming:

   - Implement optimised IPv4 checksumming routine when hardware offload
     is not in use. An IPv6 version is in the works, pending testing.

  Hardware errata:

   - Work around Cortex-A55 erratum #1530923

  Shadow call stack:

   - Work around some issues with Clang's integrated assembler not
     liking our perfectly reasonable assembly code

   - Avoid allocating the X18 register, so that it can be used to hold
     the shadow call stack pointer in future

  ACPI:

   - Fix ID count checking in IORT code. This may regress broken
     firmware that happened to work with the old implementation, in
     which case we'll have to revert it and try something else

   - Fix DAIF corruption on return from GHES handler with pseudo-NMIs

  Miscellaneous:

   - Whitelist some CPUs that are unaffected by Spectre-v2

   - Reduce frequency of ASID rollover when KPTI is compiled in but
     inactive

   - Reserve a couple of arch-specific PROT flags that are already used
     by Sparc and PowerPC and are planned for later use with BTI on
     arm64

   - Preparatory cleanup of our entry assembly code in preparation for
     moving more of it into C later on

   - Refactoring and cleanup"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (73 commits)
  arm64: acpi: fix DAIF manipulation with pNMI
  arm64: kconfig: Fix alignment of E0PD help text
  arm64: Use v8.5-RNG entropy for KASLR seed
  arm64: Implement archrandom.h for ARMv8.5-RNG
  arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
  arm64: entry: Avoid empty alternatives entries
  arm64: Kconfig: select HAVE_FUTEX_CMPXCHG
  arm64: csum: Fix pathological zero-length calls
  arm64: entry: cleanup sp_el0 manipulation
  arm64: entry: cleanup el0 svc handler naming
  arm64: entry: mark all entry code as notrace
  arm64: assembler: remove smp_dmb macro
  arm64: assembler: remove inherit_daif macro
  ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()
  mm: Reserve asm-generic prot flags 0x10 and 0x20 for arch use
  arm64: Use macros instead of hard-coded constants for MAIR_EL1
  arm64: Add KRYO{3,4}XX CPU cores to spectre-v2 safe list
  arm64: kernel: avoid x18 in __cpu_soft_restart
  arm64: kvm: stop treating register x18 as caller save
  arm64/lib: copy_page: avoid x18 register in assembler code
  ...
2020-01-27 08:58:19 -08:00
Mark Rutland
e533dbe9dc arm64: acpi: fix DAIF manipulation with pNMI
Since commit:

  d44f1b8dd7 ("arm64: KVM/mm: Move SEA handling behind a single 'claim' interface")

... the top-level APEI SEA handler has the shape:

1. current_flags = arch_local_save_flags()
2. local_daif_restore(DAIF_ERRCTX)
3. <GHES handler>
4. local_daif_restore(current_flags)

However, since commit:

  4a503217ce ("arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking")

... when pseudo-NMIs (pNMIs) are in use, arch_local_save_flags() will save
the PMR value rather than the DAIF flags.

The combination of these two commits means that the APEI SEA handler will
erroneously attempt to restore the PMR value into DAIF. Fix this by
factoring local_daif_save_flags() out of local_daif_save(), so that we
can consistently save DAIF in step #1, regardless of whether pNMIs are in
use.

Both commits were introduced concurrently in v5.0.

Cc: <stable@vger.kernel.org>
Fixes: 4a503217ce ("arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking")
Fixes: d44f1b8dd7 ("arm64: KVM/mm: Move SEA handling behind a single 'claim' interface")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-22 14:41:22 +00:00
Will Deacon
bc20606594 Merge branch 'for-next/rng' into for-next/core
* for-next/rng: (2 commits)
  arm64: Use v8.5-RNG entropy for KASLR seed
  ...
2020-01-22 11:38:53 +00:00
Will Deacon
ab3906c531 Merge branch 'for-next/errata' into for-next/core
* for-next/errata: (3 commits)
  arm64: Workaround for Cortex-A55 erratum 1530923
  ...
2020-01-22 11:35:05 +00:00
Will Deacon
aa246c056c Merge branch 'for-next/asm-annotations' into for-next/core
* for-next/asm-annotations: (6 commits)
  arm64: kernel: Correct annotation of end of el0_sync
  ...
2020-01-22 11:34:21 +00:00
Will Deacon
4f6cdf296c Merge branches 'for-next/acpi', 'for-next/cpufeatures', 'for-next/csum', 'for-next/e0pd', 'for-next/entry', 'for-next/kbuild', 'for-next/kexec/cleanup', 'for-next/kexec/file-kdump', 'for-next/misc', 'for-next/nofpsimd', 'for-next/perf' and 'for-next/scs' into for-next/core
* for-next/acpi:
  ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map()

* for-next/cpufeatures: (2 commits)
  arm64: Introduce ID_ISAR6 CPU register
  ...

* for-next/csum: (2 commits)
  arm64: csum: Fix pathological zero-length calls
  ...

* for-next/e0pd: (7 commits)
  arm64: kconfig: Fix alignment of E0PD help text
  ...

* for-next/entry: (5 commits)
  arm64: entry: cleanup sp_el0 manipulation
  ...

* for-next/kbuild: (4 commits)
  arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
  ...

* for-next/kexec/cleanup: (11 commits)
  Revert "arm64: kexec: make dtb_mem always enabled"
  ...

* for-next/kexec/file-kdump: (2 commits)
  arm64: kexec_file: add crash dump support
  ...

* for-next/misc: (12 commits)
  arm64: entry: Avoid empty alternatives entries
  ...

* for-next/nofpsimd: (7 commits)
  arm64: nofpsmid: Handle TIF_FOREIGN_FPSTATE flag cleanly
  ...

* for-next/perf: (2 commits)
  perf/imx_ddr: Fix cpu hotplug state cleanup
  ...

* for-next/scs: (6 commits)
  arm64: kernel: avoid x18 in __cpu_soft_restart
  ...
2020-01-22 11:32:31 +00:00
Will Deacon
e717d93b1c arm64: kconfig: Fix alignment of E0PD help text
Remove the additional space.

Signed-off-by: Will Deacon <will@kernel.org>
2020-01-22 11:23:54 +00:00
Mark Brown
2e8e1ea88c arm64: Use v8.5-RNG entropy for KASLR seed
When seeding KALSR on a system where we have architecture level random
number generation make use of that entropy, mixing it in with the seed
passed by the bootloader. Since this is run very early in init before
feature detection is complete we open code rather than use archrandom.h.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-22 09:54:52 +00:00
Richard Henderson
1a50ec0b3b arm64: Implement archrandom.h for ARMv8.5-RNG
Expose the ID_AA64ISAR0.RNDR field to userspace, as the RNG system
registers are always available at EL0.

Implement arch_get_random_seed_long using RNDR.  Given that the
TRNG is likely to be a shared resource between cores, and VMs,
do not explicitly force re-seeding with RNDRRS.  In order to avoid
code complexity and potential issues with hetrogenous systems only
provide values after cpufeature has finalized the system capabilities.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[Modified to only function after cpufeature has finalized the system
capabilities and move all the code into the header -- broonie]
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
[will: Advertise HWCAP via /proc/cpuinfo]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-22 09:54:18 +00:00
Dirk Behme
d7bbd6c1b0 arm64: kbuild: remove compressed images on 'make ARCH=arm64 (dist)clean'
Since v4.3-rc1 commit 0723c05fb7 ("arm64: enable more compressed
Image formats"), it is possible to build Image.{bz2,lz4,lzma,lzo}
AArch64 images. However, the commit missed adding support for removing
those images on 'make ARCH=arm64 (dist)clean'.

Fix this by adding them to the target list.
Make sure to match the order of the recipes in the makefile.

Cc: stable@vger.kernel.org # v4.3+
Fixes: 0723c05fb7 ("arm64: enable more compressed Image formats")
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-21 16:28:36 +00:00
Julien Thierry
108eae2d4d arm64: entry: Avoid empty alternatives entries
kernel_ventry will create alternative entries to potentially replace
0 instructions with 0 instructions for EL1 vectors. While this does not
cause an issue, it pointlessly takes up some bytes in the alternatives
section.

Do not generate such entries.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-21 09:55:18 +00:00
Vladimir Murzin
9834602336 arm64: Kconfig: select HAVE_FUTEX_CMPXCHG
arm64 provides always working implementation of futex_atomic_cmpxchg_inatomic(),
so there is no need to check it runtime.

Reported-by: Piyush swami <Piyush.swami@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-21 09:14:01 +00:00
Robin Murphy
c2c24edb1d arm64: csum: Fix pathological zero-length calls
In validating the checksumming results of the new routine, I sadly
neglected to test its not-checksumming results. Thus it slipped through
that the one case where @buff is already dword-aligned and @len = 0
manages to defeat the tail-masking logic and behave as if @len = 8.
For a zero length it doesn't make much sense to deference @buff anyway,
so just add an early return (which has essentially zero impact on
performance).

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 16:05:50 +00:00
Mark Rutland
3e3934176a arm64: entry: cleanup sp_el0 manipulation
The kernel stashes the current task struct in sp_el0 so that this can be
acquired consistently/cheaply when required. When we take an exception
from EL0 we have to:

1) stash the original sp_el0 value
2) find the current task
3) update sp_el0 with the current task pointer

Currently steps #1 and #2 occur in one place, and step #3 a while later.
As the value of sp_el0 is immaterial between these points, let's move
them together to make the code clearer and minimize ifdeffery. This
necessitates moving the comment for MDSCR_EL1.SS.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 13:22:14 +00:00
Mark Rutland
7a2c094464 arm64: entry: cleanup el0 svc handler naming
For most of the exception entry code, <foo>_handler() is the first C
function called from the entry assembly in entry-common.c, and external
functions handling the bulk of the logic are called do_<foo>().

For consistency, apply this scheme to el0_svc_handler and
el0_svc_compat_handler, renaming them to do_el0_svc and
do_el0_svc_compat respectively.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 13:22:14 +00:00
Mark Rutland
2d226c1e1c arm64: entry: mark all entry code as notrace
Almost all functions in entry-common.c are marked notrace, with
el1_undef and el1_inv being the only exceptions. We appear to have done
this on the assumption that there were no exception registers that we
needed to snapshot, and thus it was safe to run trace code that might
result in further exceptions and clobber those registers.

However, until we inherit the DAIF flags, our irq flag tracing is stale,
and this discrepancy could set off warnings in some configurations. For
example if CONFIG_DEBUG_LOCKDEP is selected and a trace function calls
into any flag-checking locking routines. Given we don't expect to
trigger el1_undef or el1_inv unless something is already wrong, any
irqflag warnigns are liable to mask the information we'd actually care
about.

Let's keep things simple and mark el1_undef and el1_inv as notrace.
Developers can trace do_undefinstr and bad_mode if they really want to
monitor these cases.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 13:22:14 +00:00
Mark Rutland
ddb953f86c arm64: assembler: remove smp_dmb macro
These days arm64 kernels are always SMP, and thus smp_dmb is an
overly-long way of writing dmb. Naturally, no-one uses it.

Remove the unused macro.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 13:22:13 +00:00
Mark Rutland
170b25fa6a arm64: assembler: remove inherit_daif macro
We haven't needed the inherit_daif macro since commit:

  ed3768db58 ("arm64: entry: convert el1_sync to C")

... which converted all callers to C and the local_daif_inherit
function.

Remove the unused macro.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 13:22:13 +00:00
Catalin Marinas
95b3f74bec arm64: Use macros instead of hard-coded constants for MAIR_EL1
Currently, the arm64 __cpu_setup has hard-coded constants for the memory
attributes that go into the MAIR_EL1 register. Define proper macros in
asm/sysreg.h and make use of them in proc.S.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 12:48:33 +00:00
Sai Prakash Ranjan
83b0c36b8a arm64: Add KRYO{3,4}XX CPU cores to spectre-v2 safe list
The "silver" KRYO3XX and KRYO4XX CPU cores are not affected by Spectre
variant 2. Add them to spectre_v2 safe list to correct the spurious
ARM_SMCCC_ARCH_WORKAROUND_1 warning and vulnerability status reported
under sysfs.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
[will: tweaked commit message to remove stale mention of "gold" cores]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-17 12:46:41 +00:00
Linus Torvalds
575966e080 ARM: SoC fixes
I've been sitting on these longer than I meant, so the patch count is
 a bit higher than ideal for this part of the release. There's also some
 reverts of double-applied patches that brings the diffstat up a bit.
 
 With that said, the biggest changes are:
 
  - Revert of duplicate i2c device addition on two Aspeed (BMC) Devicetrees.
  - Move of two device nodes that got applied to the wrong part of the
    tree on ASpeed G6.
  - Regulator fix for Beaglebone X15 (adding 12/5V supplies)
  - Use interrupts for keys on Amlogic SM1 to avoid missed polls
 
 In addition to that, there is a collection of smaller DT fixes:
 
  - Power supply assignment fixes for i.MX6
  - Fix of interrupt line for magnetometer on i.MX8 Librem5 devkit
  - Build fixlets (selects) for davinci/omap2+
  - More interrupt number fixes for Stratix10, Amlogic SM1, etc.
  - ... and more similar fixes across different platforms
 
 And some non-DT stuff:
 
  - optee fix to register multiple shared pages properly
  - Clock calculation fixes for MMP3
  - Clock fixes for OMAP as well
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Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM SoC fixes from Olof Johansson:
 "I've been sitting on these longer than I meant, so the patch count is
  a bit higher than ideal for this part of the release. There's also
  some reverts of double-applied patches that brings the diffstat up a
  bit.

  With that said, the biggest changes are:

   - Revert of duplicate i2c device addition on two Aspeed (BMC)
     Devicetrees.

   - Move of two device nodes that got applied to the wrong part of the
     tree on ASpeed G6.

   - Regulator fix for Beaglebone X15 (adding 12/5V supplies)

   - Use interrupts for keys on Amlogic SM1 to avoid missed polls

  In addition to that, there is a collection of smaller DT fixes:

   - Power supply assignment fixes for i.MX6

   - Fix of interrupt line for magnetometer on i.MX8 Librem5 devkit

   - Build fixlets (selects) for davinci/omap2+

   - More interrupt number fixes for Stratix10, Amlogic SM1, etc.

   - ... and more similar fixes across different platforms

  And some non-DT stuff:

   - optee fix to register multiple shared pages properly

   - Clock calculation fixes for MMP3

   - Clock fixes for OMAP as well"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (42 commits)
  MAINTAINERS: Add myself as the co-maintainer for Actions Semi platforms
  ARM: dts: imx7: Fix Toradex Colibri iMX7S 256MB NAND flash support
  ARM: dts: imx6sll-evk: Remove incorrect power supply assignment
  ARM: dts: imx6sl-evk: Remove incorrect power supply assignment
  ARM: dts: imx6sx-sdb: Remove incorrect power supply assignment
  ARM: dts: imx6qdl-sabresd: Remove incorrect power supply assignment
  ARM: dts: imx6q-icore-mipi: Use 1.5 version of i.Core MX6DL
  ARM: omap2plus: select RESET_CONTROLLER
  ARM: davinci: select CONFIG_RESET_CONTROLLER
  ARM: dts: aspeed: rainier: Fix fan fault and presence
  ARM: dts: aspeed: rainier: Remove duplicate i2c busses
  ARM: dts: aspeed: tacoma: Remove duplicate flash nodes
  ARM: dts: aspeed: tacoma: Remove duplicate i2c busses
  ARM: dts: aspeed: tacoma: Fix fsi master node
  ARM: dts: aspeed-g6: Fix FSI master location
  ARM: dts: mmp3: Fix the TWSI ranges
  clk: mmp2: Fix the order of timer mux parents
  ARM: mmp: do not divide the clock rate
  arm64: dts: rockchip: Fix IR on Beelink A1
  optee: Fix multi page dynamic shm pool alloc
  ...
2020-01-16 19:42:08 -08:00
Ard Biesheuvel
500d14affd arm64: kernel: avoid x18 in __cpu_soft_restart
The code in __cpu_soft_restart() uses x18 as an arbitrary temp register,
which will shortly be disallowed. So use x8 instead.

Link: https://patchwork.kernel.org/patch/9836877/
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[Sami: updated commit message]
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:32:56 +00:00
Ard Biesheuvel
af12376814 arm64: kvm: stop treating register x18 as caller save
In preparation of reserving x18, stop treating it as caller save in
the KVM guest entry/exit code. Currently, the code assumes there is
no need to preserve it for the host, given that it would have been
assumed clobbered anyway by the function call to __guest_enter().
Instead, preserve its value and restore it upon return.

Link: https://patchwork.kernel.org/patch/9836891/
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[Sami: updated commit message, switched from x18 to x29 for the guest context]
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:32:56 +00:00
Ard Biesheuvel
7f153ccb9b arm64/lib: copy_page: avoid x18 register in assembler code
Register x18 will no longer be used as a caller save register in the
future, so stop using it in the copy_page() code.

Link: https://patchwork.kernel.org/patch/9836869/
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[Sami: changed the offset and bias to be explicit]
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:32:56 +00:00
Sami Tolvanen
e3ec6582d1 arm64: mm: avoid x18 in idmap_kpti_install_ng_mappings
idmap_kpti_install_ng_mappings uses x18 as a temporary register, which
will result in a conflict when x18 is reserved. Use x16 and x17 instead
where needed.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:32:56 +00:00
Sami Tolvanen
c54f90c262 arm64: fix alternatives with LLVM's integrated assembler
LLVM's integrated assembler fails with the following error when
building KVM:

  <inline asm>:12:6: error: expected absolute expression
   .if kvm_update_va_mask == 0
       ^
  <inline asm>:21:6: error: expected absolute expression
   .if kvm_update_va_mask == 0
       ^
  <inline asm>:24:2: error: unrecognized instruction mnemonic
          NOT_AN_INSTRUCTION
          ^
  LLVM ERROR: Error parsing inline asm

These errors come from ALTERNATIVE_CB and __ALTERNATIVE_CFG,
which test for the existence of the callback parameter in inline
assembly using the following expression:

  " .if " __stringify(cb) " == 0\n"

This works with GNU as, but isn't supported by LLVM. This change
splits __ALTERNATIVE_CFG and ALTINSTR_ENTRY into separate macros
to fix the LLVM build.

Link: https://github.com/ClangBuiltLinux/linux/issues/472
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:32:34 +00:00
Sami Tolvanen
e0d5896bd3 arm64: lse: fix LSE atomics with LLVM's integrated assembler
Unlike gcc, clang considers each inline assembly block to be independent
and therefore, when using the integrated assembler for inline assembly,
any preambles that enable features must be repeated in each block.

This change defines __LSE_PREAMBLE and adds it to each inline assembly
block that has LSE instructions, which allows them to be compiled also
with clang's assembler.

Link: https://github.com/ClangBuiltLinux/linux/issues/671
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Andrew Murray <andrew.murray@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 17:25:10 +00:00
Robin Murphy
5777eaed56 arm64: Implement optimised checksum routine
Apparently there exist certain workloads which rely heavily on software
checksumming, for which the generic do_csum() implementation becomes a
significant bottleneck. Therefore let's give arm64 its own optimised
version - for ease of maintenance this foregoes assembly or intrisics,
and is thus not actually arm64-specific, but does rely heavily on C
idioms that translate well to the A64 ISA and the typical load/store
capabilities of most ARMv8 CPU cores.

The resulting increase in checksum throughput scales nicely with buffer
size, tending towards 4x for a small in-order core (Cortex-A53), and up
to 6x or more for an aggressive big core (Ampere eMAG).

Reported-by: Lingyan Huang <huanglingyan2@huawei.com>
Tested-by: Lingyan Huang <huanglingyan2@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 15:23:29 +00:00
Vladimir Murzin
f88f42f853 arm64: context: Free up kernel ASIDs if KPTI is not in use
We can extend user ASID space if it turns out that system does not
require KPTI. We start with kernel ASIDs reserved because CPU caps are
not finalized yet and free them up lazily on the next rollover if we
confirm than KPTI is not in use.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 12:45:05 +00:00
Steven Price
275fa0ea2c arm64: Workaround for Cortex-A55 erratum 1530923
Cortex-A55 erratum 1530923 allows TLB entries to be allocated as a
result of a speculative AT instruction. This may happen in the middle of
a guest world switch while the relevant VMSA configuration is in an
inconsistent state, leading to erroneous content being allocated into
TLBs.

The same workaround as is used for Cortex-A76 erratum 1165522
(WORKAROUND_SPECULATIVE_AT_VHE) can be used here. Note that this
mandates the use of VHE on affected parts.

Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 10:44:14 +00:00
Steven Price
db0d46a58d arm64: Rename WORKAROUND_1319367 to SPECULATIVE_AT_NVHE
To match SPECULATIVE_AT_VHE let's also have a generic name for the NVHE
variant.

Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 10:44:11 +00:00
Steven Price
e85d68faed arm64: Rename WORKAROUND_1165522 to SPECULATIVE_AT_VHE
Cortex-A55 is affected by a similar erratum, so rename the existing
workaround for errarum 1165522 so it can be used for both errata.

Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-16 10:43:53 +00:00
Will Deacon
a569f5f372 arm64: Use register field helper in kaslr_requires_kpti()
Rather than open-code the extraction of the E0PD field from the MMFR2
register, we can use the cpuid_feature_extract_unsigned_field() helper
instead.

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 16:49:48 +00:00
Will Deacon
ebac96ede6 arm64: Simplify early check for broken TX1 when KASLR is enabled
Now that the decision to use non-global mappings is stored in a variable,
the check to avoid enabling them for the terminally broken ThunderX1
platform can be simplified so that it is only keyed off the MIDR value.

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 16:49:27 +00:00
Vladimir Murzin
8bf9284d99 arm64: Turn "broken gas inst" into real config option
Use the new 'as-instr' Kconfig macro to define CONFIG_BROKEN_GAS_INST
directly, making it available everywhere.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
[will: Drop redundant 'y if' logic]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 16:35:12 +00:00
Mark Brown
09e3c22a86 arm64: Use a variable to store non-global mappings decision
Refactor the code which checks to see if we need to use non-global
mappings to use a variable instead of checking with the CPU capabilities
each time, doing the initial check for KPTI early in boot before we
start allocating memory so we still avoid transitioning to non-global
mappings in common cases.

Since this variable always matches our decision about non-global
mappings this means we can also combine arm64_kernel_use_ng_mappings()
and arm64_unmap_kernel_at_el0() into a single function, the variable
simply stores the result and the decision code is elsewhere. We could
just have the users check the variable directly but having a function
makes it clear that these uses are read-only.

The result is that we simplify the code a bit and reduces the amount of
code executed at runtime.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 14:11:18 +00:00
Mark Brown
92ac6fd162 arm64: Don't use KPTI where we have E0PD
Since E0PD is intended to fulfil the same role as KPTI we don't need to
use KPTI on CPUs where E0PD is available, we can rely on E0PD instead.
Change the check that forces KPTI on when KASLR is enabled to check for
E0PD before doing so, CPUs with E0PD are not expected to be affected by
meltdown so should not need to enable KPTI for other reasons.

Since E0PD is a system capability we will still enable KPTI if any of
the CPUs in the system lacks E0PD, this will rewrite any global mappings
that were established in systems where some but not all CPUs support
E0PD.  We may transiently have a mix of global and non-global mappings
while booting since we use the local CPU when deciding if KPTI will be
required prior to completing CPU enumeration but any global mappings
will be converted to non-global ones when KPTI is applied.

KPTI can still be forced on from the command line if required.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 14:11:17 +00:00
Mark Brown
c2d92353b2 arm64: Factor out checks for KASLR in KPTI code into separate function
In preparation for integrating E0PD support with KASLR factor out the
checks for interaction between KASLR and KPTI done in boot context into
a new function kaslr_requires_kpti(), in the process clarifying the
distinction between what we do in boot context and what we do at
runtime.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 14:11:17 +00:00
Mark Brown
3e6c69a058 arm64: Add initial support for E0PD
Kernel Page Table Isolation (KPTI) is used to mitigate some speculation
based security issues by ensuring that the kernel is not mapped when
userspace is running but this approach is expensive and is incompatible
with SPE.  E0PD, introduced in the ARMv8.5 extensions, provides an
alternative to this which ensures that accesses from userspace to the
kernel's half of the memory map to always fault with constant time,
preventing timing attacks without requiring constant unmapping and
remapping or preventing legitimate accesses.

Currently this feature will only be enabled if all CPUs in the system
support E0PD, if some CPUs do not support the feature at boot time then
the feature will not be enabled and in the unlikely event that a late
CPU is the first CPU to lack the feature then we will reject that CPU.

This initial patch does not yet integrate with KPTI, this will be dealt
with in followup patches.  Ideally we could ensure that by default we
don't use KPTI on CPUs where E0PD is present.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: Fixed typo in Kconfig text]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 14:11:02 +00:00
Catalin Marinas
395af86137 arm64: Move the LSE gas support detection to Kconfig
As the Kconfig syntax gained support for $(as-instr) tests, move the LSE
gas support detection from Makefile to the main arm64 Kconfig and remove
the additional CONFIG_AS_LSE definition and check.

Cc: Will Deacon <will@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 12:50:48 +00:00
Anshuman Khandual
8e3747beff arm64: Introduce ID_ISAR6 CPU register
This adds basic building blocks required for ID_ISAR6 CPU register which
identifies support for various instruction implementation on AArch32 state.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[will: Ensure SPECRES is treated the same as on A64]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 11:13:27 +00:00
Steven Price
d4209d8b71 arm64: cpufeature: Export matrix and other features to userspace
Export the features introduced as part of ARMv8.6 exposed in the
ID_AA64ISAR1_EL1 and ID_AA64ZFR0_EL1 registers. This introduces the
Matrix features (ARMv8.2-I8MM, ARMv8.2-F64MM and ARMv8.2-F32MM) along
with BFloat16 (Armv8.2-BF16), speculation invalidation (SPECRES) and
Data Gathering Hint (ARMv8.0-DGH).

Signed-off-by: Julien Grall <julien.grall@arm.com>
[Added other features in those registers]
Signed-off-by: Steven Price <steven.price@arm.com>
[will: Don't advertise SPECRES to userspace]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 11:13:07 +00:00
Suzuki K Poulose
52f73c383b arm64: nofpsmid: Handle TIF_FOREIGN_FPSTATE flag cleanly
We detect the absence of FP/SIMD after an incapable CPU is brought up,
and by then we have kernel threads running already with TIF_FOREIGN_FPSTATE set
which could be set for early userspace applications (e.g, modprobe triggered
from initramfs) and init. This could cause the applications to loop forever in
do_nofity_resume() as we never clear the TIF flag, once we now know that
we don't support FP.

Fix this by making sure that we clear the TIF_FOREIGN_FPSTATE flag
for tasks which may have them set, as we would have done in the normal
case, but avoiding touching the hardware state (since we don't support any).

Also to make sure we handle the cases seemlessly we categorise the
helper functions to two :
 1) Helpers for common core code, which calls into take appropriate
    actions without knowing the current FPSIMD state of the CPU/task.

    e.g fpsimd_restore_current_state(), fpsimd_flush_task_state(),
        fpsimd_save_and_flush_cpu_state().

    We bail out early for these functions, taking any appropriate actions
    (e.g, clearing the TIF flag) where necessary to hide the handling
    from core code.

 2) Helpers used when the presence of FP/SIMD is apparent.
    i.e, save/restore the FP/SIMD register state, modify the CPU/task
    FP/SIMD state.
    e.g,

    fpsimd_save(), task_fpsimd_load() - save/restore task FP/SIMD registers

    fpsimd_bind_task_to_cpu()  \
                                - Update the "state" metadata for CPU/task.
    fpsimd_bind_state_to_cpu() /

    fpsimd_update_current_state() - Update the fp/simd state for the current
                                    task from memory.

    These must not be called in the absence of FP/SIMD. Put in a WARNING
    to make sure they are not invoked in the absence of FP/SIMD.

KVM also uses the TIF_FOREIGN_FPSTATE flag to manage the FP/SIMD state
on the CPU. However, without FP/SIMD support we trap all accesses and
inject undefined instruction. Thus we should never "load" guest state.
Add a sanity check to make sure this is valid.

Fixes: 82e0191a1a ("arm64: Support systems without FP/ASIMD")
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:11:53 +00:00
Suzuki K Poulose
6d502b6ba1 arm64: signal: nofpsimd: Handle fp/simd context for signal frames
Make sure we try to save/restore the vfp/fpsimd context for signal
handling only when the fp/simd support is available. Otherwise, skip
the frames.

Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:11:46 +00:00
Suzuki K Poulose
c9d66999f0 arm64: ptrace: nofpsimd: Fail FP/SIMD regset operations
When fp/simd is not supported on the system, fail the operations
of FP/SIMD regsets.

Fixes: 82e0191a1a ("arm64: Support systems without FP/ASIMD")
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:11:39 +00:00
Suzuki K Poulose
7559950aef arm64: cpufeature: Set the FP/SIMD compat HWCAP bits properly
We set the compat_elf_hwcap bits unconditionally on arm64 to
include the VFP and NEON support. However, the FP/SIMD unit
is optional on Arm v8 and thus could be missing. We already
handle this properly in the kernel, but still advertise to
the COMPAT applications that the VFP is available. Fix this
to make sure we only advertise when we really have them.

Fixes: 82e0191a1a ("arm64: Support systems without FP/ASIMD")
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:11:36 +00:00
Suzuki K Poulose
449443c03d arm64: cpufeature: Fix the type of no FP/SIMD capability
The NO_FPSIMD capability is defined with scope SYSTEM, which implies
that the "absence" of FP/SIMD on at least one CPU is detected only
after all the SMP CPUs are brought up. However, we use the status
of this capability for every context switch. So, let us change
the scope to LOCAL_CPU to allow the detection of this capability
as and when the first CPU without FP is brought up.

Also, the current type allows hotplugged CPU to be brought up without
FP/SIMD when all the current CPUs have FP/SIMD and we have the userspace
up. Fix both of these issues by changing the capability to
BOOT_RESTRICTED_LOCAL_CPU_FEATURE.

Fixes: 82e0191a1a ("arm64: Support systems without FP/ASIMD")
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:11:31 +00:00
Suzuki K Poulose
0cd82feb01 arm64: fpsimd: Make sure SVE setup is complete before SIMD is used
In-kernel users of NEON rely on may_use_simd() to check if the SIMD
can be used. However, we must initialize the SVE before SIMD can
be used. Add a sanity check to make sure that we have completed the
SVE setup before anyone uses the SIMD.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:11:21 +00:00
Suzuki K Poulose
b51c6ac220 arm64: Introduce system_capabilities_finalized() marker
We finalize the system wide capabilities after the SMP CPUs
are booted by the kernel. This is used as a marker for deciding
various checks in the kernel. e.g, sanity check the hotplugged
CPUs for missing mandatory features.

However there is no explicit helper available for this in the
kernel. There is sys_caps_initialised, which is not exposed.
The other closest one we have is the jump_label arm64_const_caps_ready
which denotes that the capabilities are set and the capability checks
could use the individual jump_labels for fast path. This is
performed before setting the ELF Hwcaps, which must be checked
against the new CPUs. We also perform some of the other initialization
e.g, SVE setup, which is important for the use of FP/SIMD
where SVE is supported. Normally userspace doesn't get to run
before we finish this. However the in-kernel users may
potentially start using the neon mode. So, we need to
reject uses of neon mode before we are set. Instead of defining
a new marker for the completion of SVE setup, we could simply
reuse the arm64_const_caps_ready and enable it once we have
finished all the setup. Also we could expose this to the
various users as "system_capabilities_finalized()" to make
it more meaningful than "const_caps_ready".

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-14 17:10:21 +00:00