From 501c8de7b061d2dc0c21a0a79fee3eddf30af8dd Mon Sep 17 00:00:00 2001 From: LEROY Christophe Date: Tue, 19 May 2015 17:18:57 +0200 Subject: [PATCH] powerpc: add support for csum_add() The C version of csum_add() as defined in include/net/checksum.h gives the following assembly in ppc32: 0: 7c 04 1a 14 add r0,r4,r3 4: 7c 64 00 10 subfc r3,r4,r0 8: 7c 63 19 10 subfe r3,r3,r3 c: 7c 63 00 50 subf r3,r3,r0 and the following in ppc64: 0xc000000000001af8 <+0>: add r3,r3,r4 0xc000000000001afc <+4>: cmplw cr7,r3,r4 0xc000000000001b00 <+8>: mfcr r4 0xc000000000001b04 <+12>: rlwinm r4,r4,29,31,31 0xc000000000001b08 <+16>: add r3,r4,r3 0xc000000000001b0c <+20>: clrldi r3,r3,32 0xc000000000001b10 <+24>: blr include/net/checksum.h also offers the possibility to define an arch specific function. This patch provides a specific csum_add() inline function. Signed-off-by: Christophe Leroy Signed-off-by: Scott Wood --- arch/powerpc/include/asm/checksum.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h index 5e43d2d40084..e8d9ef4755a4 100644 --- a/arch/powerpc/include/asm/checksum.h +++ b/arch/powerpc/include/asm/checksum.h @@ -130,6 +130,22 @@ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); } +#define HAVE_ARCH_CSUM_ADD +static inline __wsum csum_add(__wsum csum, __wsum addend) +{ +#ifdef __powerpc64__ + u64 res = (__force u64)csum; + + res += (__force u64)addend; + return (__force __wsum)((u32)res + (res >> 32)); +#else + asm("addc %0,%0,%1;" + "addze %0,%0;" + : "+r" (csum) : "r" (addend)); + return csum; +#endif +} + #endif #endif /* __KERNEL__ */ #endif -- GitLab