On Fri, Sep 19, 2008 at 01:47:43PM +0200, Ralf Baechle wrote: > I'm interested in test reports of this on all sorts of configurations - > 32-bit, 64-bit, big / little endian, R2 processors and pre-R2. In > particular Cavium being the only MIPS64 R2 implementation would be > interesting. This definately is stuff which should go upstream for 2.6.27. There was a trivial bug in the R2 code. >From 97ad23f4696a322cb3bc379a25a8c0f6526751d6 Mon Sep 17 00:00:00 2001 From: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Date: Fri, 19 Sep 2008 14:05:53 +0200 Subject: [PATCH] [MIPS] Fix 64-bit csum_partial, __csum_partial_copy_user and csum_partial_copy On 64-bit machines it wouldn't handle a possible carry when adding the 32-bit folded checksum and checksum argument. While at it, add a few trivial optimizations, also for R2 processors. Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> diff --git a/arch/mips/lib/csum_partial.S b/arch/mips/lib/csum_partial.S index 8d77841..c77a7a0 100644 --- a/arch/mips/lib/csum_partial.S +++ b/arch/mips/lib/csum_partial.S @@ -53,12 +53,14 @@ #define UNIT(unit) ((unit)*NBYTES) #define ADDC(sum,reg) \ - .set push; \ - .set noat; \ ADD sum, reg; \ sltu v1, sum, reg; \ ADD sum, v1; \ - .set pop + +#define ADDC32(sum,reg) \ + addu sum, reg; \ + sltu v1, sum, reg; \ + addu sum, v1; \ #define CSUM_BIGCHUNK1(src, offset, sum, _t0, _t1, _t2, _t3) \ LOAD _t0, (offset + UNIT(0))(src); \ @@ -254,8 +256,6 @@ LEAF(csum_partial) 1: ADDC(sum, t1) /* fold checksum */ - .set push - .set noat #ifdef USE_DOUBLE dsll32 v1, sum, 0 daddu sum, v1 @@ -263,24 +263,25 @@ LEAF(csum_partial) dsra32 sum, sum, 0 addu sum, v1 #endif - sll v1, sum, 16 - addu sum, v1 - sltu v1, sum, v1 - srl sum, sum, 16 - addu sum, v1 /* odd buffer alignment? */ - beqz t7, 1f - nop - sll v1, sum, 8 +#ifdef CPU_MIPSR2 + wsbh v1, sum + movn sum, v1, t7 +#else + beqz t7, 1f /* odd buffer alignment? */ + lui v1, 0x00ff + addu v1, 0x00ff + and t0, sum, v1 + sll t0, t0, 8 srl sum, sum, 8 - or sum, v1 - andi sum, 0xffff - .set pop + and sum, sum, v1 + or sum, sum, t0 1: +#endif .set reorder /* Add the passed partial csum. */ - ADDC(sum, a2) + ADDC32(sum, a2) jr ra .set noreorder END(csum_partial) @@ -656,8 +657,6 @@ EXC( sb t0, NBYTES-2(dst), .Ls_exc) ADDC(sum, t2) .Ldone: /* fold checksum */ - .set push - .set noat #ifdef USE_DOUBLE dsll32 v1, sum, 0 daddu sum, v1 @@ -665,23 +664,23 @@ EXC( sb t0, NBYTES-2(dst), .Ls_exc) dsra32 sum, sum, 0 addu sum, v1 #endif - sll v1, sum, 16 - addu sum, v1 - sltu v1, sum, v1 - srl sum, sum, 16 - addu sum, v1 - /* odd buffer alignment? */ - beqz odd, 1f - nop - sll v1, sum, 8 +#ifdef CPU_MIPSR2 + wsbh v1, sum + movn sum, v1, odd +#else + beqz odd, 1f /* odd buffer alignment? */ + lui v1, 0x00ff + addu v1, 0x00ff + and t0, sum, v1 + sll t0, t0, 8 srl sum, sum, 8 - or sum, v1 - andi sum, 0xffff - .set pop + and sum, sum, v1 + or sum, sum, t0 1: +#endif .set reorder - ADDC(sum, psum) + ADDC32(sum, psum) jr ra .set noreorder
