Commit Graph

23 Commits

Author SHA1 Message Date
Mark Brown 81ff692ad9 arm64/sysreg: Add hwcap for SVE EBF16
SVE has a separate identification register indicating support for BFloat16
operations. Add a hwcap identifying support for EBF16 in this register,
mirroring what we did for the non-SVE case.

While there is currently an architectural requirement for BF16 support to
be the same in SVE and non-SVE contexts there are separate identification
registers this separate hwcap helps avoid issues if that requirement were
to be relaxed in the future, we have already chosen to have a separate
capability for base BF16 support.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220829154815.832347-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-09-06 18:53:52 +01:00
Martin Liška 0b52f76351 docs/arm64: elf_hwcaps: unify newlines in HWCAP lists
Unify horizontal spacing (remove extra newlines) which
are sensitive to visual presentation by Sphinx.

Fixes: 5e64b862c4 ("arm64/sme: Basic enumeration support")
Signed-off-by: Martin Liska <mliska@suse.cz>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/84e3d6cc-75cf-d6f3-9bb8-be02075aaf6d@suse.cz
Signed-off-by: Will Deacon <will@kernel.org>
2022-08-23 10:38:39 +01:00
Linus Torvalds aad26f55f4 This was a moderately busy cycle for documentation, but nothing all that
earth-shaking:
 
 - More Chinese translations, and an update to the Italian translations.
   The Japanese, Korean, and traditional Chinese translations are
   more-or-less unmaintained at this point, instead.
 
 - Some build-system performance improvements.
 
 - The removal of the archaic submitting-drivers.rst document, with the
   movement of what useful material that remained into other docs.
 
 - Improvements to sphinx-pre-install to, hopefully, give more useful
   suggestions.
 
 - A number of build-warning fixes
 
 Plus the usual collection of typo fixes, updates, and more.
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Merge tag 'docs-6.0' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "This was a moderately busy cycle for documentation, but nothing
  all that earth-shaking:

   - More Chinese translations, and an update to the Italian
     translations.

     The Japanese, Korean, and traditional Chinese translations
     are more-or-less unmaintained at this point, instead.

   - Some build-system performance improvements.

   - The removal of the archaic submitting-drivers.rst document,
     with the movement of what useful material that remained into
     other docs.

   - Improvements to sphinx-pre-install to, hopefully, give more
     useful suggestions.

   - A number of build-warning fixes

  Plus the usual collection of typo fixes, updates, and more"

* tag 'docs-6.0' of git://git.lwn.net/linux: (92 commits)
  docs: efi-stub: Fix paths for x86 / arm stubs
  Docs/zh_CN: Update the translation of sched-stats to 5.19-rc8
  Docs/zh_CN: Update the translation of pci to 5.19-rc8
  Docs/zh_CN: Update the translation of pci-iov-howto to 5.19-rc8
  Docs/zh_CN: Update the translation of usage to 5.19-rc8
  Docs/zh_CN: Update the translation of testing-overview to 5.19-rc8
  Docs/zh_CN: Update the translation of sparse to 5.19-rc8
  Docs/zh_CN: Update the translation of kasan to 5.19-rc8
  Docs/zh_CN: Update the translation of iio_configfs to 5.19-rc8
  doc:it_IT: align Italian documentation
  docs: Remove spurious tag from admin-guide/mm/overcommit-accounting.rst
  Documentation: process: Update email client instructions for Thunderbird
  docs: ABI: correct QEMU fw_cfg spec path
  doc/zh_CN: remove submitting-driver reference from docs
  docs: zh_TW: align to submitting-drivers removal
  docs: zh_CN: align to submitting-drivers removal
  docs: ko_KR: howto: remove reference to removed submitting-drivers
  docs: ja_JP: howto: remove reference to removed submitting-drivers
  docs: it_IT: align to submitting-drivers removal
  docs: process: remove outdated submitting-drivers.rst
  ...
2022-08-02 19:24:24 -07:00
Mark Brown a6a468f50d arm64/hwcap: Support FEAT_EBF16
The v9.2 feature FEAT_EBF16 provides support for an extended BFloat16 mode.
Allow userspace to discover system support for this feature by adding a
hwcap for it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220707103632.12745-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-07-20 11:18:11 +01:00
Martin Liška 94bdaa7d9a docs/arm64: elf_hwcaps: Unify HWCAP lists as description lists
Add a series of blank lines to this document to get consistend rendering as
an RST description list.

Signed-off-by: Martin Liska <mliska@suse.cz>
Link: https://lore.kernel.org/r/d0e576ab-6121-b7d7-da5b-7750f05ca7f4@suse.cz
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-06-13 11:31:39 -06:00
Marc Zyngier b2c4caf331 Merge branch kvm-arm64/wfxt into kvmarm-master/next
* kvm-arm64/wfxt:
  : .
  : Add support for the WFET/WFIT instructions that provide the same
  : service as WFE/WFI, only with a timeout.
  : .
  KVM: arm64: Expose the WFXT feature to guests
  KVM: arm64: Offer early resume for non-blocking WFxT instructions
  KVM: arm64: Handle blocking WFIT instruction
  KVM: arm64: Introduce kvm_counter_compute_delta() helper
  KVM: arm64: Simplify kvm_cpu_has_pending_timer()
  arm64: Use WFxT for __delay() when possible
  arm64: Add wfet()/wfit() helpers
  arm64: Add HWCAP advertising FEAT_WFXT
  arm64: Add RV and RN fields for ESR_ELx_WFx_ISS
  arm64: Expand ESR_ELx_WFx_ISS_TI to match its ARMv8.7 definition

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-04 09:42:16 +01:00
Mark Brown 5e64b862c4 arm64/sme: Basic enumeration support
This patch introduces basic cpufeature support for discovering the presence
of the Scalable Matrix Extension.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-9-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:50:49 +01:00
Marc Zyngier 69bb02ebc3 arm64: Add HWCAP advertising FEAT_WFXT
In order to allow userspace to enjoy WFET, add a new HWCAP that
advertises it when available.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419182755.601427-9-maz@kernel.org
2022-04-20 13:24:44 +01:00
Mark Brown d082a0255f arm64/mte: Add hwcap for asymmetric mode
Allow userspace to detect support for asymmetric mode by providing a hwcap
for it, using the official feature name FEAT_MTE3.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Tested-by: Branislav Rankov <branislav.rankov@arm.com>
Link: https://lore.kernel.org/r/20220216173224.2342152-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-02-25 14:41:05 +00:00
Joey Gouly 1175011a7d arm64: cpufeature: add HWCAP for FEAT_RPRES
Add a new HWCAP to detect the Increased precision of Reciprocal Estimate
and Reciprocal Square Root Estimate feature (FEAT_RPRES), introduced in Armv8.7.

Also expose this to userspace in the ID_AA64ISAR2_EL1 feature register.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211210165432.8106-4-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-13 18:53:00 +00:00
Joey Gouly 5c13f042e7 arm64: cpufeature: add HWCAP for FEAT_AFP
Add a new HWCAP to detect the Alternate Floating-point Behaviour
feature (FEAT_AFP), introduced in Armv8.7.

Also expose this to userspace in the ID_AA64MMFR1_EL1 feature register.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211210165432.8106-2-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-13 18:52:59 +00:00
Marc Zyngier fee29f008a arm64: Add HWCAP for self-synchronising virtual counter
Since userspace can make use of the CNTVSS_EL0 instruction, expose
it via a HWCAP.

Suggested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-18-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2021-10-19 10:56:20 +01:00
Catalin Marinas 5d8505fd03 arm64: Fix the documented event stream frequency
It should be 10KHz, matching the ARCH_TIMER_EVT_STREAM_PERIOD_US of
100us.

Note that this is only a documentation bug.

Fixes: 611a7bc74e ("arm64: docs: describe ELF hwcaps")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210505132845.23698-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-05-05 18:34:28 +01:00
Bailu Lin 2472943cd4 Documentation: Chinese translation of Documentation/arm64/elf_hwcaps.rst
This is a Chinese translated version of
 Documentation/arm64/elf_hwcaps.rst

Signed-off-by: Bailu Lin <bailu.lin@vivo.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20201124023846.34826-1-bailu.lin@vivo.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-11-30 10:36:45 -07:00
Vincenzo Frascino df9d7a22dd arm64: mte: Add Memory Tagging Extension documentation
Memory Tagging Extension (part of the ARMv8.5 Extensions) provides
a mechanism to detect the sources of memory related errors which
may be vulnerable to exploitation, including bounds violations,
use-after-free, use-after-return, use-out-of-scope and use before
initialization errors.

Add Memory Tagging Extension documentation for the arm64 linux
kernel support.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Will Deacon <will@kernel.org>
2020-09-04 12:46:07 +01:00
Dave Martin 8ef8f360cf arm64: Basic Branch Target Identification support
This patch adds the bare minimum required to expose the ARMv8.5
Branch Target Identification feature to userspace.

By itself, this does _not_ automatically enable BTI for any initial
executable pages mapped by execve().  This will come later, but for
now it should be possible to enable BTI manually on those pages by
using mprotect() from within the target process.

Other arches already using the generic mman.h are already using
0x10 for arch-specific prot flags, so we use that for PROT_BTI
here.

For consistency, signal handler entry points in BTI guarded pages
are required to be annotated as such, just like any other function.
This blocks a relatively minor attack vector, but comforming
userspace will have the annotations anyway, so we may as well
enforce them.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-16 17:19:48 +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
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
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
Julien Grall 0f6e4c4016 docs/arm64: elf_hwcaps: Document HWCAP_SB
All the hardware capabilities but HWCAP_SB is not documented in
elf_hwcaps.rst. So document it.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:54:08 +01:00
Julien Grall 3a25e46c99 docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value
Part of the hardware capabilities documented in elf_hwcap.rst are
ordered following the definition in the header
arch/arm64/include/uapi/asm/hwcap.h but others seems to be documented
in random order.

To make easier to match against the definition in the header, they are
now sorted in the same order as they are defined in header. I.e.,
HWCAP first by ascending value, and then HWCAP2 in the similar fashion.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:54:08 +01:00
Linus Torvalds e9a83bd232 It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro.  These create more
    than the usual number of simple but annoying merge conflicts with other
    trees, unfortunately.  He has a lot more of these waiting on the wings
    that, I think, will go to you directly later on.
 
  - A new document on how to use merges and rebases in kernel repos, and one
    on Spectre vulnerabilities.
 
  - Various improvements to the build system, including automatic markup of
    function() references because some people, for reasons I will never
    understand, were of the opinion that :c:func:``function()`` is
    unattractive and not fun to type.
 
  - We now recommend using sphinx 1.7, but still support back to 1.4.
 
  - Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
Mauro Carvalho Chehab b693d0b372 docs: arm64: convert docs to ReST and rename to .rst
The documentation is in a format that is very close to ReST format.

The conversion is actually:
  - add blank lines in order to identify paragraphs;
  - fixing tables markups;
  - adding some lists markups;
  - marking literal blocks;
  - adjust some title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:20:27 -06:00