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| author |   Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-03-09 08:56:14 +0100 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-05-08 22:15:40 +1000 |
| commit | a1ae431705410fc7092790977bffd1b00c63c229 (patch) | |
| tree | a0b0938ab2130f315bb4689df0dcda781897e71c | |
| parent | powerpc: Add missing headers (diff) | |
| download | linux-dev-a1ae431705410fc7092790977bffd1b00c63c229.tar.xz linux-dev-a1ae431705410fc7092790977bffd1b00c63c229.zip | |
powerpc: Use rol32() instead of opencoding in csum_fold()
rol32(x, 16) will do the rotate using rlwinm.
No need to open code using inline assembly.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/794337eff7bb803d2c4e67d9eee635390c4c48fe.1646812553.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/include/asm/checksum.h | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h index 8321f6053a67..4b573a3b7e17 100644 --- a/arch/powerpc/include/asm/checksum.h +++ b/arch/powerpc/include/asm/checksum.h @@ -38,14 +38,15 @@ extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, */ static inline __sum16 csum_fold(__wsum sum) { - unsigned int tmp; - - /* swap the two 16-bit halves of sum */ - __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); - /* if there is a carry from adding the two 16-bit halves, - it will carry from the lower half into the upper half, - giving us the correct sum in the upper half. */ - return (__force __sum16)(~((__force u32)sum + tmp) >> 16); + u32 tmp = (__force u32)sum; + + /* + * swap the two 16-bit halves of sum + * if there is a carry from adding the two 16-bit halves, + * it will carry from the lower half into the upper half, + * giving us the correct sum in the upper half. + */ + return (__force __sum16)(~(tmp + rol32(tmp, 16)) >> 16); } static inline u32 from64to32(u64 x) |