[GIT PULL] arm64 FPSIMD buffer on-stack for 6.19

[GIT PULL] arm64 FPSIMD buffer on-stack for 6.19

[Eric Biggers]

Note: this is more of a core arm64 change.  However, I was asked to take
this because most uses of kernel-mode FPSIMD are in crypto or CRC code.
There were also conflicts with lib/crypto/ changes this cycle, which I
resolved.  But as a result, this depends on the pull request "Crypto
library updates for 6.19".  So that one needs to be merged first.

The following changes since commit 2dbb6f4a25d38fcf7d6c1c682e45a13e6bbe9562:

  fscrypt: Drop obsolete recommendation to enable optimized POLYVAL (2025-11-11 11:03:39 -0800)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git tags/fpsimd-on-stack-for-linus

for you to fetch changes up to 5dc8d277520be6f0be11f36712e557167b3964c8:

  Merge tag 'arm64-fpsimd-on-stack-for-v6.19' into libcrypto-fpsimd-on-stack (2025-11-12 10:15:07 -0800)

----------------------------------------------------------------

In v6.8, the size of task_struct on arm64 increased by 528 bytes due
to the new 'kernel_fpsimd_state' field. This field was added to allow
kernel-mode FPSIMD code to be preempted.

Unfortunately, 528 bytes is kind of a lot for task_struct. This
regression in the task_struct size was noticed and reported.

Recover that space by making this state be allocated on the stack at
the beginning of each kernel-mode FPSIMD section.

To make it easier for all the users of kernel-mode FPSIMD to do that
correctly, introduce and use a 'scoped_ksimd' abstraction.

----------------------------------------------------------------
Ard Biesheuvel (23):
      arm64/simd: Add scoped guard API for kernel mode SIMD
      ARM/simd: Add scoped guard API for kernel mode SIMD
      lib/crypto: Switch ARM and arm64 to 'ksimd' scoped guard API
      lib/crc: Switch ARM and arm64 to 'ksimd' scoped guard API
      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
      crypto: aegis128-neon - Move to more abstract 'ksimd' guard API
      raid6: Move to more abstract 'ksimd' 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
      lib/crypto: arm/blake2b: Move to scoped ksimd API
      lib/crypto: arm64: Move remaining algorithms to scoped ksimd API

Eric Biggers (2):
      Merge tag 'scoped-ksimd-for-arm-arm64' into libcrypto-fpsimd-on-stack
      Merge tag 'arm64-fpsimd-on-stack-for-v6.19' into libcrypto-fpsimd-on-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/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           |   7 +-
 arch/arm64/include/asm/simd.h                |  10 ++
 arch/arm64/include/asm/xor.h                 |  22 ++-
 arch/arm64/kernel/fpsimd.c                   |  54 +++++--
 crypto/aegis128-neon.c                       |  33 ++---
 drivers/net/ethernet/mellanox/mlx5/core/wc.c |  19 +--
 lib/crc/arm/crc-t10dif.h                     |  19 +--
 lib/crc/arm/crc32.h                          |  11 +-
 lib/crc/arm64/crc-t10dif.h                   |  19 +--
 lib/crc/arm64/crc32.h                        |  16 +-
 lib/crypto/arm/blake2b.h                     |   5 +-
 lib/crypto/arm/chacha.h                      |  11 +-
 lib/crypto/arm/curve25519.h                  |   5 +-
 lib/crypto/arm/poly1305.h                    |   6 +-
 lib/crypto/arm/sha1.h                        |  13 +-
 lib/crypto/arm/sha256.h                      |  12 +-
 lib/crypto/arm/sha512.h                      |   5 +-
 lib/crypto/arm64/chacha.h                    |  11 +-
 lib/crypto/arm64/poly1305.h                  |   6 +-
 lib/crypto/arm64/polyval.h                   |  24 ++-
 lib/crypto/arm64/sha1.h                      |   7 +-
 lib/crypto/arm64/sha256.h                    |  19 +--
 lib/crypto/arm64/sha3.h                      |  13 +-
 lib/crypto/arm64/sha512.h                    |   8 +-
 lib/raid6/neon.c                             |  17 +--
 lib/raid6/recov_neon.c                       |  15 +-
 42 files changed, 617 insertions(+), 712 deletions(-)

Re: [GIT PULL] arm64 FPSIMD buffer on-stack for 6.19

[pr-tracker-bot]

The pull request you sent on Sat, 29 Nov 2025 19:01:05 -0800:

> https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux.git tags/fpsimd-on-stack-for-linus

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/f617d24606553159a271f43e36d1c71a4c317e48

Thank you!

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