Commit a1ae4317 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/794337eff7bb803d2c4e67d9eee635390c4c48fe.1646812553.git.christophe.leroy@csgroup.eu
parent e6f6390a

arch/powerpc/include/asm/checksum.h

+9 −8
Original line number Diff line number Diff line
@@ -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)