From: Matteo Croce <mcroce@linux.microsoft.com>
To: linux-riscv@lists.infradead.org
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Atish Patra <atish.patra@wdc.com>,
Emil Renner Berthing <kernel@esmil.dk>,
Akira Tsukamoto <akira.tsukamoto@gmail.com>,
Drew Fustini <drew@beagleboard.org>,
Bin Meng <bmeng.cn@gmail.com>,
David Laight <David.Laight@aculab.com>,
Guo Ren <guoren@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: [PATCH v5 0/3] riscv: optimized mem* functions
Date: Wed, 29 Sep 2021 19:22:31 +0200 [thread overview]
Message-ID: <20210929172234.31620-1-mcroce@linux.microsoft.com> (raw)
From: Matteo Croce <mcroce@microsoft.com>
Replace the assembly mem{cpy,move,set} with C equivalent.
Try to access RAM with the largest bit width possible, but without
doing unaligned accesses.
A further improvement could be to use multiple read and writes as the
assembly version was trying to do.
Tested on a BeagleV Starlight with a SiFive U74 core, where the
improvement is noticeable.
v4 -> v5:
- call __memcpy() instead of memcpy() in memmove()
v3 -> v4:
- incorporate changes from proposed generic version:
https://lore.kernel.org/lkml/20210702123153.14093-1-mcroce@linux.microsoft.com/
v2 -> v3:
- alias mem* to __mem* and not viceversa
- use __alias instead of a tail call
v1 -> v2:
- reduce the threshold from 64 to 16 bytes
- fix KASAN build
- optimize memset
Matteo Croce (3):
riscv: optimized memcpy
riscv: optimized memmove
riscv: optimized memset
arch/riscv/include/asm/string.h | 18 ++--
arch/riscv/kernel/Makefile | 1 -
arch/riscv/kernel/riscv_ksyms.c | 17 ----
arch/riscv/lib/Makefile | 4 +-
arch/riscv/lib/memcpy.S | 108 ----------------------
arch/riscv/lib/memmove.S | 64 -------------
arch/riscv/lib/memset.S | 113 -----------------------
arch/riscv/lib/string.c | 154 ++++++++++++++++++++++++++++++++
8 files changed, 164 insertions(+), 315 deletions(-)
delete mode 100644 arch/riscv/kernel/riscv_ksyms.c
delete mode 100644 arch/riscv/lib/memcpy.S
delete mode 100644 arch/riscv/lib/memmove.S
delete mode 100644 arch/riscv/lib/memset.S
create mode 100644 arch/riscv/lib/string.c
--
2.31.1
next reply other threads:[~2021-09-29 17:22 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-29 17:22 Matteo Croce [this message]
2021-09-29 17:22 ` [PATCH v5 1/3] riscv: optimized memcpy Matteo Croce
2021-09-30 1:24 ` Guo Ren
2021-09-30 1:36 ` Matteo Croce
2021-09-30 19:43 ` Vineet Gupta
2021-10-01 8:06 ` David Laight
2021-10-01 11:23 ` Pavel Machek
2021-10-02 17:20 ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 2/3] riscv: optimized memmove Matteo Croce
2021-09-29 17:22 ` [PATCH v5 3/3] riscv: optimized memset Matteo Croce
2021-11-25 10:56 ` Ley Foon Tan
2021-12-06 20:37 ` Emil Renner Berthing
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