diff options
Diffstat (limited to 'arch/sh/lib/checksum.S')
| -rw-r--r-- | arch/sh/lib/checksum.S | 69 |
1 files changed, 50 insertions, 19 deletions
diff --git a/arch/sh/lib/checksum.S b/arch/sh/lib/checksum.S index cbdd0d4..356c8ec9 100644 --- a/arch/sh/lib/checksum.S +++ b/arch/sh/lib/checksum.S @@ -36,8 +36,7 @@ */ /* - * unsigned int csum_partial(const unsigned char *buf, int len, - * unsigned int sum); + * asmlinkage __wsum csum_partial(const void *buf, int len, __wsum sum); */ .text @@ -49,11 +48,31 @@ ENTRY(csum_partial) * Fortunately, it is easy to convert 2-byte alignment to 4-byte * alignment for the unrolled loop. */ - mov r5, r1 mov r4, r0 - tst #2, r0 ! Check alignment. - bt 2f ! Jump if alignment is ok. + tst #3, r0 ! Check alignment. + bt/s 2f ! Jump if alignment is ok. + mov r4, r7 ! Keep a copy to check for alignment ! + tst #1, r0 ! Check alignment. + bt 21f ! Jump if alignment is boundary of 2bytes. + + ! buf is odd + tst r5, r5 + add #-1, r5 + bt 9f + mov.b @r4+, r0 + extu.b r0, r0 + addc r0, r6 ! t=0 from previous tst + mov r6, r0 + shll8 r6 + shlr16 r0 + shlr8 r0 + or r0, r6 + mov r4, r0 + tst #2, r0 + bt 2f +21: + ! buf is 2 byte aligned (len could be 0) add #-2, r5 ! Alignment uses up two bytes. cmp/pz r5 ! bt/s 1f ! Jump if we had at least two bytes. @@ -61,16 +80,17 @@ ENTRY(csum_partial) bra 6f add #2, r5 ! r5 was < 2. Deal with it. 1: - mov r5, r1 ! Save new len for later use. mov.w @r4+, r0 extu.w r0, r0 addc r0, r6 bf 2f add #1, r6 2: + ! buf is 4 byte aligned (len could be 0) + mov r5, r1 mov #-5, r0 - shld r0, r5 - tst r5, r5 + shld r0, r1 + tst r1, r1 bt/s 4f ! if it's =0, go to 4f clrt .align 2 @@ -92,30 +112,31 @@ ENTRY(csum_partial) addc r0, r6 addc r2, r6 movt r0 - dt r5 + dt r1 bf/s 3b cmp/eq #1, r0 - ! here, we know r5==0 - addc r5, r6 ! add carry to r6 + ! here, we know r1==0 + addc r1, r6 ! add carry to r6 4: - mov r1, r0 + mov r5, r0 and #0x1c, r0 tst r0, r0 - bt/s 6f - mov r0, r5 - shlr2 r5 + bt 6f + ! 4 bytes or more remaining + mov r0, r1 + shlr2 r1 mov #0, r2 5: addc r2, r6 mov.l @r4+, r2 movt r0 - dt r5 + dt r1 bf/s 5b cmp/eq #1, r0 addc r2, r6 - addc r5, r6 ! r5==0 here, so it means add carry-bit + addc r1, r6 ! r1==0 here, so it means add carry-bit 6: - mov r1, r5 + ! 3 bytes or less remaining mov #3, r0 and r0, r5 tst r5, r5 @@ -139,8 +160,18 @@ ENTRY(csum_partial) 8: addc r0, r6 mov #0, r0 - addc r0, r6 + addc r0, r6 9: + ! Check if the buffer was misaligned, if so realign sum + mov r7, r0 + tst #1, r0 + bt 10f + mov r6, r0 + shll8 r6 + shlr16 r0 + shlr8 r0 + or r0, r6 +10: rts mov r6, r0 |
