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microblaze: Fix stack usage in PAGE_SIZE copy_tofrom_user

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If access to user space failed we need to reconstruct
stack pointer and restore all register.

This patch fixed problem introduces by:
"microblaze: Add loop unrolling for PAGE in copy_tofrom_user"
(sha1: ebe211254b)

Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
Michal Simek 2012-03-30 08:21:38 +02:00
parent a28d73ca3a
commit ac64a9caa5
1 changed files with 62 additions and 36 deletions
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98
arch/microblaze/lib/uaccess_old.S
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@ -122,22 +122,22 @@ __strnlen_user:
15: swi r24, r5, 0x0018 + offset; \
16: swi r25, r5, 0x001C + offset; \
.section __ex_table,"a"; \
.word 1b, 0f; \
.word 2b, 0f; \
.word 3b, 0f; \
.word 4b, 0f; \
.word 5b, 0f; \
.word 6b, 0f; \
.word 7b, 0f; \
.word 8b, 0f; \
.word 9b, 0f; \
.word 10b, 0f; \
.word 11b, 0f; \
.word 12b, 0f; \
.word 13b, 0f; \
.word 14b, 0f; \
.word 15b, 0f; \
.word 16b, 0f; \
.word 1b, 33f; \
.word 2b, 33f; \
.word 3b, 33f; \
.word 4b, 33f; \
.word 5b, 33f; \
.word 6b, 33f; \
.word 7b, 33f; \
.word 8b, 33f; \
.word 9b, 33f; \
.word 10b, 33f; \
.word 11b, 33f; \
.word 12b, 33f; \
.word 13b, 33f; \
.word 14b, 33f; \
.word 15b, 33f; \
.word 16b, 33f; \
.text
#define COPY_80(offset) \
@ -190,14 +190,17 @@ w2: sw r4, r5, r3
.align 4 /* Alignment is important to keep icache happy */
page: /* Create room on stack and save registers for storign values */
addik r1, r1, -32
swi r19, r1, 4
swi r20, r1, 8
swi r21, r1, 12
swi r22, r1, 16
swi r23, r1, 20
swi r24, r1, 24
swi r25, r1, 28
addik r1, r1, -40
swi r5, r1, 0
swi r6, r1, 4
swi r7, r1, 8
swi r19, r1, 12
swi r20, r1, 16
swi r21, r1, 20
swi r22, r1, 24
swi r23, r1, 28
swi r24, r1, 32
swi r25, r1, 36
loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */
/* Loop unrolling to get performance boost */
COPY_80(0x000);
@ -205,21 +208,44 @@ loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */
COPY_80(0x100);
COPY_80(0x180);
/* copy loop */
addik r6, r6, 0x200
addik r7, r7, -0x200
bneid r7, loop
addik r5, r5, 0x200
addik r6, r6, 0x200
addik r7, r7, -0x200
bneid r7, loop
addik r5, r5, 0x200
/* Restore register content */
lwi r19, r1, 4
lwi r20, r1, 8
lwi r21, r1, 12
lwi r22, r1, 16
lwi r23, r1, 20
lwi r24, r1, 24
lwi r25, r1, 28
addik r1, r1, 32
lwi r5, r1, 0
lwi r6, r1, 4
lwi r7, r1, 8
lwi r19, r1, 12
lwi r20, r1, 16
lwi r21, r1, 20
lwi r22, r1, 24
lwi r23, r1, 28
lwi r24, r1, 32
lwi r25, r1, 36
addik r1, r1, 40
/* return back */
addik r3, r0, 0
rtsd r15, 8
nop
/* Fault case - return temp count */
33:
addik r3, r7, 0
/* Restore register content */
lwi r5, r1, 0
lwi r6, r1, 4
lwi r7, r1, 8
lwi r19, r1, 12
lwi r20, r1, 16
lwi r21, r1, 20
lwi r22, r1, 24
lwi r23, r1, 28
lwi r24, r1, 32
lwi r25, r1, 36
addik r1, r1, 40
/* return back */
rtsd r15, 8
nop