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| author |  Robin Murphy <robin.murphy@arm.com>
| 2020-01-15 16:42:39 +0000 |
|---|---|---|
| committer |  Will Deacon <will@kernel.org>
| 2020-01-16 15:23:29 +0000 |
| commit | 5777eaed566a1d63e344d3dd8f2b5e33be20643e (patch) | |
| tree | 9bf4f13c0209f26135e66073760b297ba0cac0d9 /arch/arm64/include | |
| parent | Linux 5.5-rc3 (diff) | |
| download | linux-5777eaed566a1d63e344d3dd8f2b5e33be20643e.tar.gz linux-5777eaed566a1d63e344d3dd8f2b5e33be20643e.tar.bz2 linux-5777eaed566a1d63e344d3dd8f2b5e33be20643e.zip | |
arm64: Implement optimised checksum routine
Apparently there exist certain workloads which rely heavily on software
checksumming, for which the generic do_csum() implementation becomes a
significant bottleneck. Therefore let's give arm64 its own optimised
version - for ease of maintenance this foregoes assembly or intrisics,
and is thus not actually arm64-specific, but does rely heavily on C
idioms that translate well to the A64 ISA and the typical load/store
capabilities of most ARMv8 CPU cores.
The resulting increase in checksum throughput scales nicely with buffer
size, tending towards 4x for a small in-order core (Cortex-A53), and up
to 6x or more for an aggressive big core (Ampere eMAG).
Reported-by: Lingyan Huang <huanglingyan2@huawei.com>
Tested-by: Lingyan Huang <huanglingyan2@huawei.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/checksum.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/checksum.h b/arch/arm64/include/asm/checksum.h index d064a50deb5f..8d2a7de39744 100644 --- a/arch/arm64/include/asm/checksum.h +++ b/arch/arm64/include/asm/checksum.h @@ -35,6 +35,9 @@ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) } #define ip_fast_csum ip_fast_csum +extern unsigned int do_csum(const unsigned char *buff, int len); +#define do_csum do_csum + #include <asm-generic/checksum.h> #endif /* __ASM_CHECKSUM_H */ |