diff options
Diffstat (limited to 'arch/sh/lib/checksum.S')
| -rw-r--r-- | arch/sh/lib/checksum.S | 54 |
1 files changed, 52 insertions, 2 deletions
diff --git a/arch/sh/lib/checksum.S b/arch/sh/lib/checksum.S index b34a65383..3317b3ccc 100644 --- a/arch/sh/lib/checksum.S +++ b/arch/sh/lib/checksum.S @@ -185,15 +185,65 @@ ENTRY(csum_partial_copy_generic) mov.l r5,@-r15 mov.l r6,@-r15 + mov #3, r0 ! Check src and dest are equally aligned + mov r4, r1 + and r0, r1 + and r5, r0 + cmp/eq r1, r0 + bf 3f ! Different alignments, use slow version + tst #1,r0 ! Check dest word aligned + bf 3f ! If not, do it the slow way + mov #2,r0 - tst r0,r5 ! Check alignment. + tst r0,r5 ! Check dest alignment. bt 2f ! Jump if alignment is ok. add #-2,r6 ! Alignment uses up two bytes. cmp/pz r6 ! Jump if we had at least two bytes. bt/s 1f clrt bra 4f - add #2,r6 ! $r6 was < 2. Deal with it. + add #2,r6 ! $r6 was < 2. Deal with it. + +3: ! Handle different src and dest alinments. + ! This is not common, so simple byte by byte copy will do. + mov r6, r2 + shlr r6 + tst r6, r6 + bt 4f + clrt +SRC(5: mov.b @r4+,r0 ) +DST( mov.b r0,@r5 ) + add #1, r5 +SRC( mov.b @r4+,r1 ) +DST( mov.b r1,@r5 ) + add #1,r5 + + extu.b r0,r0 + extu.b r1,r1 +#ifdef __LITTLE_ENDIAN__ + shll8 r1 +#else + shll8 r0 +#endif + or r1,r0 + + addc r0,r7 + movt r0 + dt r6 + bf/s 5b + cmp/eq #1,r0 + mov #0,r0 + addc r0, r7 + + mov r2, r0 + tst #1, r0 + bt 7f + bra 5f + clrt + + ! src and dest equally aligned, but to a two byte boundary. + ! Handle first two bytes as a special case + .align 5 SRC(1: mov.w @r4+,r0 ) DST( mov.w r0,@r5 ) add #2,r5 |