[PATCH v3 00/21] arm64: Move kernel mode FPSIMD buffer to the stack

[Ard Biesheuvel <ardb+git@google.com>]

From: Ard Biesheuvel <ardb@kernel.org>

Move the buffer for preserving/restoring the kernel mode FPSIMD state on a
context switch out of struct thread_struct, and onto the stack, so that
the memory cost is not imposed needlessly on all tasks in the system.

Changes since v2:
- Fix generic kernel mode FPU api instead of removing it.

- Rebase onto v6.18-rc0 and fix the fallout

- Prefer WARN() over BUG() in kernel_neon_begin/end

- Avoid unnecessary cmpxchg() calls

- When invoked in softirq context, use the caller provided buffer rather
  than the one stored in the task struct - this permits callers from
  task context (including users of the generic kernel mode FPU api) to
  pass NULL as the buffer when running with preemption disabled.

- Add acks from Kees and Eric; Mark's was dropped along with the patch
  in question.

- Fix new occurrence of kernel_neon_begin/end in Mellanox driver.

Changes since v1:
- Add a patch reverting the arm64 support for the generic
  kernel_fpu_begin()/end() API, which is problematic on arm64.

- Introduce a new 'ksimd' scoped guard that encapsulates the calls the
  kernel_neon_begin() and kernel_neon_end() at a higher level of
  abstraction. This makes it straight-forward to plumb in the stack
  buffer without complicating the callers.

- Move all kernel mode NEON users on arm64 (and some on ARM) over to the
  new API.

- Add Mark's ack to patches #6 - #8

Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Eric Biggers <ebiggers@kernel.org>

Ard Biesheuvel (21):
  crypto/arm64: aes-ce-ccm - Avoid pointless yield of the NEON unit
  crypto/arm64: sm4-ce-ccm - Avoid pointless yield of the NEON unit
  crypto/arm64: sm4-ce-gcm - Avoid pointless yield of the NEON unit
  arm64/simd: Add scoped guard API for kernel mode SIMD
  ARM/simd: Add scoped guard API for kernel mode SIMD
  crypto: aegis128-neon - Move to more abstract 'ksimd' guard API
  raid6: Move to more abstract 'ksimd' guard API
  lib/crc: Switch ARM and arm64 to 'ksimd' scoped guard API
  lib/crypto: Switch ARM and arm64 to 'ksimd' scoped guard API
  crypto/arm64: aes-ccm - Switch to 'ksimd' scoped guard API
  crypto/arm64: aes-blk - Switch to 'ksimd' scoped guard API
  crypto/arm64: aes-gcm - Switch to 'ksimd' scoped guard API
  crypto/arm64: nhpoly1305 - Switch to 'ksimd' scoped guard API
  crypto/arm64: polyval - Switch to 'ksimd' scoped guard API
  crypto/arm64: sha3 - Switch to 'ksimd' scoped guard API
  crypto/arm64: sm3 - Switch to 'ksimd' scoped guard API
  crypto/arm64: sm4 - Switch to 'ksimd' scoped guard API
  arm64/xorblocks:  Switch to 'ksimd' scoped guard API
  net/mlx5: Switch to more abstract scoped ksimd guard API on arm64
  arm64/fpu: Enforce task-context only for generic kernel mode FPU
  arm64/fpsimd: Allocate kernel mode FP/SIMD buffers on the stack

 arch/arm/include/asm/simd.h                  |   7 +
 arch/arm64/crypto/aes-ce-ccm-glue.c          | 116 +++++------
 arch/arm64/crypto/aes-ce-glue.c              |  87 ++++----
 arch/arm64/crypto/aes-glue.c                 | 139 ++++++-------
 arch/arm64/crypto/aes-neonbs-glue.c          | 150 +++++++-------
 arch/arm64/crypto/ghash-ce-glue.c            |  27 ++-
 arch/arm64/crypto/nhpoly1305-neon-glue.c     |   5 +-
 arch/arm64/crypto/polyval-ce-glue.c          |  12 +-
 arch/arm64/crypto/sha3-ce-glue.c             |  10 +-
 arch/arm64/crypto/sm3-ce-glue.c              |  15 +-
 arch/arm64/crypto/sm3-neon-glue.c            |  16 +-
 arch/arm64/crypto/sm4-ce-ccm-glue.c          |  49 ++---
 arch/arm64/crypto/sm4-ce-cipher-glue.c       |  10 +-
 arch/arm64/crypto/sm4-ce-gcm-glue.c          |  62 ++----
 arch/arm64/crypto/sm4-ce-glue.c              | 214 +++++++++-----------
 arch/arm64/crypto/sm4-neon-glue.c            |  25 +--
 arch/arm64/include/asm/fpu.h                 |  16 +-
 arch/arm64/include/asm/neon.h                |   4 +-
 arch/arm64/include/asm/processor.h           |   2 +-
 arch/arm64/include/asm/simd.h                |  10 +
 arch/arm64/include/asm/xor.h                 |  22 +-
 arch/arm64/kernel/fpsimd.c                   |  44 ++--
 crypto/aegis128-neon.c                       |  33 ++-
 drivers/net/ethernet/mellanox/mlx5/core/wc.c |  19 +-
 lib/crc/arm/crc-t10dif.h                     |  16 +-
 lib/crc/arm/crc32.h                          |  11 +-
 lib/crc/arm64/crc-t10dif.h                   |  16 +-
 lib/crc/arm64/crc32.h                        |  16 +-
 lib/crypto/arm/chacha.h                      |   6 +-
 lib/crypto/arm/poly1305.h                    |   6 +-
 lib/crypto/arm/sha1.h                        |  13 +-
 lib/crypto/arm/sha256.h                      |  12 +-
 lib/crypto/arm/sha512.h                      |   6 +-
 lib/crypto/arm64/chacha.h                    |  11 +-
 lib/crypto/arm64/poly1305.h                  |   6 +-
 lib/crypto/arm64/sha1.h                      |   7 +-
 lib/crypto/arm64/sha256.h                    |  19 +-
 lib/crypto/arm64/sha512.h                    |   8 +-
 lib/raid6/neon.c                             |  17 +-
 lib/raid6/recov_neon.c                       |  15 +-
 40 files changed, 587 insertions(+), 692 deletions(-)


base-commit: 0d97f2067c166eb495771fede9f7b73999c67f66
-- 
2.51.0.710.ga91ca5db03-goog