powerpc: Avoid unaligned loads and stores in boot memcpy code

[pandora-kernel.git] / arch / powerpc / boot / string.S

diff --git a/arch/powerpc/boot/string.S b/arch/powerpc/boot/string.S
index b1eeaed..ac3d43b 100644 (file)
--- a/arch/powerpc/boot/string.S
+++ b/arch/powerpc/boot/string.S
@@ -107,10 +107,12 @@ memcpy:
        rlwinm. r7,r5,32-3,3,31         /* r7 = r5 >> 3 */
        addi    r6,r3,-4
        addi    r4,r4,-4
-       beq     2f                      /* if less than 8 bytes to do */
+       beq     3f                      /* if less than 8 bytes to do */
        andi.   r0,r6,3                 /* get dest word aligned */
        mtctr   r7
        bne     5f
+       andi.   r0,r4,3                 /* check src word aligned too */
+       bne     3f
 1:     lwz     r7,4(r4)
        lwzu    r8,8(r4)
        stw     r7,4(r6)
@@ -132,6 +134,11 @@ memcpy:
        bdnz    4b
        blr
 5:     subfic  r0,r0,4
+       cmpw    cr1,r0,r5
+       add     r7,r0,r4
+       andi.   r7,r7,3                 /* will source be word-aligned too? */
+       ble     cr1,3b
+       bne     3b                      /* do byte-by-byte if not */
        mtctr   r0
 6:     lbz     r7,4(r4)
        addi    r4,r4,1
@@ -149,10 +156,12 @@ backwards_memcpy:
        rlwinm. r7,r5,32-3,3,31         /* r7 = r5 >> 3 */
        add     r6,r3,r5
        add     r4,r4,r5
-       beq     2f
+       beq     3f
        andi.   r0,r6,3
        mtctr   r7
        bne     5f
+       andi.   r0,r4,3
+       bne     3f
 1:     lwz     r7,-4(r4)
        lwzu    r8,-8(r4)
        stw     r7,-4(r6)
@@ -171,7 +180,12 @@ backwards_memcpy:
        stbu    r0,-1(r6)
        bdnz    4b
        blr
-5:     mtctr   r0
+5:     cmpw    cr1,r0,r5
+       subf    r7,r0,r4
+       andi.   r7,r7,3
+       ble     cr1,3b
+       bne     3b
+       mtctr   r0
 6:     lbzu    r7,-1(r4)
        stbu    r7,-1(r6)
        bdnz    6b