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From: ard.biesheuvel@linaro.org (Ard Biesheuvel)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 0/4] arm64: wire CRC32 instructions into core crc32 routines
Date: Mon, 27 Aug 2018 13:02:41 +0200	[thread overview]
Message-ID: <20180827110245.14812-1-ard.biesheuvel@linaro.org> (raw)

There are many crc32 users in the kernel that call the library routine
rather than the crypto API wrapper, and so none of these callers use the
accelerated arm64 instructions when available.

While this is not known to cause performance issues, calling a table based
time variant implementation with a non-negligible D-cache footprint (8 KB)
is wasteful in any case, and now that the crc32 instructions have been made
mandatory in the architecture, let's wire them up into the core crc routines.

This also means that they will be exposed to the crypto API via the generic
CRC32 driver, and so we can remove the scalar routines from the crypto API
driver. This leaves the PMULL code, which will only be useful on systems
that implement 64x64 PMULL but not the CRC32 instructions. Given that no
such systems are known to exist, this driver is removed entirely in patch #4.

Ard Biesheuvel (4):
  lib/crc32: make core crc32() routines weak so they can be overridden
  arm64: cpufeature: add feature for CRC32 instructions
  arm64/lib: add accelerated crc32 routines
  crypto: arm64/crc32 - remove PMULL based CRC32 driver

 arch/arm64/Kconfig                |   1 +
 arch/arm64/configs/defconfig      |   1 -
 arch/arm64/crypto/Kconfig         |   5 -
 arch/arm64/crypto/Makefile        |   3 -
 arch/arm64/crypto/crc32-ce-core.S | 287 --------------------
 arch/arm64/crypto/crc32-ce-glue.c | 244 -----------------
 arch/arm64/include/asm/cpucaps.h  |   3 +-
 arch/arm64/kernel/cpufeature.c    |   9 +
 arch/arm64/lib/Makefile           |   2 +
 arch/arm64/lib/crc32.S            |  60 ++++
 lib/crc32.c                       |  11 +-
 11 files changed, 81 insertions(+), 545 deletions(-)
 delete mode 100644 arch/arm64/crypto/crc32-ce-core.S
 delete mode 100644 arch/arm64/crypto/crc32-ce-glue.c
 create mode 100644 arch/arm64/lib/crc32.S

-- 
2.18.0

             reply	other threads:[~2018-08-27 11:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-27 11:02 Ard Biesheuvel [this message]
2018-08-27 11:02 ` [PATCH 1/4] lib/crc32: make core crc32() routines weak so they can be overridden Ard Biesheuvel
2018-09-04  9:44   ` Herbert Xu
2018-08-27 11:02 ` [PATCH 2/4] arm64: cpufeature: add feature for CRC32 instructions Ard Biesheuvel
2018-08-28 17:01   ` Will Deacon
2018-08-28 18:43     ` Ard Biesheuvel
2018-09-04  3:18       ` Herbert Xu
2018-09-04  9:38         ` Will Deacon
2018-09-04  9:44           ` Herbert Xu
2018-09-10 15:45         ` Catalin Marinas
2018-08-27 11:02 ` [PATCH 3/4] arm64/lib: add accelerated crc32 routines Ard Biesheuvel
2018-08-27 11:02 ` [PATCH 4/4] crypto: arm64/crc32 - remove PMULL based CRC32 driver Ard Biesheuvel
2018-09-04  5:21   ` Herbert Xu
2018-08-27 14:53 ` [PATCH 0/4] arm64: wire CRC32 instructions into core crc32 routines Theodore Y. Ts'o
2018-08-27 15:18   ` Ard Biesheuvel

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