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linux/arch/sparc/lib/copy_user.S
David S. Miller 3a1d5c84ed [SPARC]: Don't zero out tail during copy_from_user_inatomic(). 
Actually, since we use the same code for all the copying
types in and out of userspace, we check at runtime whether
preemption is disabled.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-29 16:12:41 -07:00

496 lines
10 KiB
ArmAsm
Raw Blame History

/* copy_user.S: Sparc optimized copy_from_user and copy_to_user code.
*
* Copyright(C) 1995 Linus Torvalds
* Copyright(C) 1996 David S. Miller
* Copyright(C) 1996 Eddie C. Dost
* Copyright(C) 1996,1998 Jakub Jelinek
*
* derived from:
* e-mail between David and Eddie.
*
* Returns 0 if successful, otherwise count of bytes not copied yet
*/
#include <asm/ptrace.h>
#include <asm/asmmacro.h>
#include <asm/page.h>
#include <asm/thread_info.h>
/* Work around cpp -rob */
#define ALLOC #alloc
#define EXECINSTR #execinstr
#define EX(x,y,a,b) \
98: x,y; \
.section .fixup,ALLOC,EXECINSTR; \
.align 4; \
99: ba fixupretl; \
a, b, %g3; \
.section __ex_table,ALLOC; \
.align 4; \
.word 98b, 99b; \
.text; \
.align 4
#define EX2(x,y,c,d,e,a,b) \
98: x,y; \
.section .fixup,ALLOC,EXECINSTR; \
.align 4; \
99: c, d, e; \
ba fixupretl; \
a, b, %g3; \
.section __ex_table,ALLOC; \
.align 4; \
.word 98b, 99b; \
.text; \
.align 4
#define EXO2(x,y) \
98: x, y; \
.section __ex_table,ALLOC; \
.align 4; \
.word 98b, 97f; \
.text; \
.align 4
#define EXT(start,end,handler) \
.section __ex_table,ALLOC; \
.align 4; \
.word start, 0, end, handler; \
.text; \
.align 4
/* Please do not change following macros unless you change logic used
* in .fixup at the end of this file as well
*/
/* Both these macros have to start with exactly the same insn */
#define MOVE_BIGCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
ldd [%src + (offset) + 0x00], %t0; \
ldd [%src + (offset) + 0x08], %t2; \
ldd [%src + (offset) + 0x10], %t4; \
ldd [%src + (offset) + 0x18], %t6; \
st %t0, [%dst + (offset) + 0x00]; \
st %t1, [%dst + (offset) + 0x04]; \
st %t2, [%dst + (offset) + 0x08]; \
st %t3, [%dst + (offset) + 0x0c]; \
st %t4, [%dst + (offset) + 0x10]; \
st %t5, [%dst + (offset) + 0x14]; \
st %t6, [%dst + (offset) + 0x18]; \
st %t7, [%dst + (offset) + 0x1c];
#define MOVE_BIGALIGNCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
ldd [%src + (offset) + 0x00], %t0; \
ldd [%src + (offset) + 0x08], %t2; \
ldd [%src + (offset) + 0x10], %t4; \
ldd [%src + (offset) + 0x18], %t6; \
std %t0, [%dst + (offset) + 0x00]; \
std %t2, [%dst + (offset) + 0x08]; \
std %t4, [%dst + (offset) + 0x10]; \
std %t6, [%dst + (offset) + 0x18];
#define MOVE_LASTCHUNK(src, dst, offset, t0, t1, t2, t3) \
ldd [%src - (offset) - 0x10], %t0; \
ldd [%src - (offset) - 0x08], %t2; \
st %t0, [%dst - (offset) - 0x10]; \
st %t1, [%dst - (offset) - 0x0c]; \
st %t2, [%dst - (offset) - 0x08]; \
st %t3, [%dst - (offset) - 0x04];
#define MOVE_HALFCHUNK(src, dst, offset, t0, t1, t2, t3) \
lduh [%src + (offset) + 0x00], %t0; \
lduh [%src + (offset) + 0x02], %t1; \
lduh [%src + (offset) + 0x04], %t2; \
lduh [%src + (offset) + 0x06], %t3; \
sth %t0, [%dst + (offset) + 0x00]; \
sth %t1, [%dst + (offset) + 0x02]; \
sth %t2, [%dst + (offset) + 0x04]; \
sth %t3, [%dst + (offset) + 0x06];
#define MOVE_SHORTCHUNK(src, dst, offset, t0, t1) \
ldub [%src - (offset) - 0x02], %t0; \
ldub [%src - (offset) - 0x01], %t1; \
stb %t0, [%dst - (offset) - 0x02]; \
stb %t1, [%dst - (offset) - 0x01];
.text
.align 4
.globl __copy_user_begin
__copy_user_begin:
.globl __copy_user
dword_align:
andcc %o1, 1, %g0
be 4f
andcc %o1, 2, %g0
EXO2(ldub [%o1], %g2)
add %o1, 1, %o1
EXO2(stb %g2, [%o0])
sub %o2, 1, %o2
bne 3f
add %o0, 1, %o0
EXO2(lduh [%o1], %g2)
add %o1, 2, %o1
EXO2(sth %g2, [%o0])
sub %o2, 2, %o2
b 3f
add %o0, 2, %o0
4:
EXO2(lduh [%o1], %g2)
add %o1, 2, %o1
EXO2(sth %g2, [%o0])
sub %o2, 2, %o2
b 3f
add %o0, 2, %o0
__copy_user: /* %o0=dst %o1=src %o2=len */
xor %o0, %o1, %o4
1:
andcc %o4, 3, %o5
2:
bne cannot_optimize
cmp %o2, 15
bleu short_aligned_end
andcc %o1, 3, %g0
bne dword_align
3:
andcc %o1, 4, %g0
be 2f
mov %o2, %g1
EXO2(ld [%o1], %o4)
sub %g1, 4, %g1
EXO2(st %o4, [%o0])
add %o1, 4, %o1
add %o0, 4, %o0
2:
andcc %g1, 0xffffff80, %g7
be 3f
andcc %o0, 4, %g0
be ldd_std + 4
5:
MOVE_BIGCHUNK(o1, o0, 0x00, o2, o3, o4, o5, g2, g3, g4, g5)
MOVE_BIGCHUNK(o1, o0, 0x20, o2, o3, o4, o5, g2, g3, g4, g5)
MOVE_BIGCHUNK(o1, o0, 0x40, o2, o3, o4, o5, g2, g3, g4, g5)
MOVE_BIGCHUNK(o1, o0, 0x60, o2, o3, o4, o5, g2, g3, g4, g5)
80:
EXT(5b, 80b, 50f)
subcc %g7, 128, %g7
add %o1, 128, %o1
bne 5b
add %o0, 128, %o0
3:
andcc %g1, 0x70, %g7
be copy_user_table_end
andcc %g1, 8, %g0
sethi %hi(copy_user_table_end), %o5
srl %g7, 1, %o4
add %g7, %o4, %o4
add %o1, %g7, %o1
sub %o5, %o4, %o5
jmpl %o5 + %lo(copy_user_table_end), %g0
add %o0, %g7, %o0
copy_user_table:
MOVE_LASTCHUNK(o1, o0, 0x60, g2, g3, g4, g5)
MOVE_LASTCHUNK(o1, o0, 0x50, g2, g3, g4, g5)
MOVE_LASTCHUNK(o1, o0, 0x40, g2, g3, g4, g5)
MOVE_LASTCHUNK(o1, o0, 0x30, g2, g3, g4, g5)
MOVE_LASTCHUNK(o1, o0, 0x20, g2, g3, g4, g5)
MOVE_LASTCHUNK(o1, o0, 0x10, g2, g3, g4, g5)
MOVE_LASTCHUNK(o1, o0, 0x00, g2, g3, g4, g5)
copy_user_table_end:
EXT(copy_user_table, copy_user_table_end, 51f)
be copy_user_last7
andcc %g1, 4, %g0
EX(ldd [%o1], %g2, and %g1, 0xf)
add %o0, 8, %o0
add %o1, 8, %o1
EX(st %g2, [%o0 - 0x08], and %g1, 0xf)
EX2(st %g3, [%o0 - 0x04], and %g1, 0xf, %g1, sub %g1, 4)
copy_user_last7:
be 1f
andcc %g1, 2, %g0
EX(ld [%o1], %g2, and %g1, 7)
add %o1, 4, %o1
EX(st %g2, [%o0], and %g1, 7)
add %o0, 4, %o0
1:
be 1f
andcc %g1, 1, %g0
EX(lduh [%o1], %g2, and %g1, 3)
add %o1, 2, %o1
EX(sth %g2, [%o0], and %g1, 3)
add %o0, 2, %o0
1:
be 1f
nop
EX(ldub [%o1], %g2, add %g0, 1)
EX(stb %g2, [%o0], add %g0, 1)
1:
retl
clr %o0
ldd_std:
MOVE_BIGALIGNCHUNK(o1, o0, 0x00, o2, o3, o4, o5, g2, g3, g4, g5)
MOVE_BIGALIGNCHUNK(o1, o0, 0x20, o2, o3, o4, o5, g2, g3, g4, g5)
MOVE_BIGALIGNCHUNK(o1, o0, 0x40, o2, o3, o4, o5, g2, g3, g4, g5)
MOVE_BIGALIGNCHUNK(o1, o0, 0x60, o2, o3, o4, o5, g2, g3, g4, g5)
81:
EXT(ldd_std, 81b, 52f)
subcc %g7, 128, %g7
add %o1, 128, %o1
bne ldd_std
add %o0, 128, %o0
andcc %g1, 0x70, %g7
be copy_user_table_end
andcc %g1, 8, %g0
sethi %hi(copy_user_table_end), %o5
srl %g7, 1, %o4
add %g7, %o4, %o4
add %o1, %g7, %o1
sub %o5, %o4, %o5
jmpl %o5 + %lo(copy_user_table_end), %g0
add %o0, %g7, %o0
cannot_optimize:
bleu short_end
cmp %o5, 2
bne byte_chunk
and %o2, 0xfffffff0, %o3
andcc %o1, 1, %g0
be 10f
nop
EXO2(ldub [%o1], %g2)
add %o1, 1, %o1
EXO2(stb %g2, [%o0])
sub %o2, 1, %o2
andcc %o2, 0xfffffff0, %o3
be short_end
add %o0, 1, %o0
10:
MOVE_HALFCHUNK(o1, o0, 0x00, g2, g3, g4, g5)
MOVE_HALFCHUNK(o1, o0, 0x08, g2, g3, g4, g5)
82:
EXT(10b, 82b, 53f)
subcc %o3, 0x10, %o3
add %o1, 0x10, %o1
bne 10b
add %o0, 0x10, %o0
b 2f
and %o2, 0xe, %o3
byte_chunk:
MOVE_SHORTCHUNK(o1, o0, -0x02, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x04, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x06, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x08, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x0a, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x0c, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x0e, g2, g3)
MOVE_SHORTCHUNK(o1, o0, -0x10, g2, g3)
83:
EXT(byte_chunk, 83b, 54f)
subcc %o3, 0x10, %o3
add %o1, 0x10, %o1
bne byte_chunk
add %o0, 0x10, %o0
short_end:
and %o2, 0xe, %o3
2:
sethi %hi(short_table_end), %o5
sll %o3, 3, %o4
add %o0, %o3, %o0
sub %o5, %o4, %o5
add %o1, %o3, %o1
jmpl %o5 + %lo(short_table_end), %g0
andcc %o2, 1, %g0
84:
MOVE_SHORTCHUNK(o1, o0, 0x0c, g2, g3)
MOVE_SHORTCHUNK(o1, o0, 0x0a, g2, g3)
MOVE_SHORTCHUNK(o1, o0, 0x08, g2, g3)
MOVE_SHORTCHUNK(o1, o0, 0x06, g2, g3)
MOVE_SHORTCHUNK(o1, o0, 0x04, g2, g3)
MOVE_SHORTCHUNK(o1, o0, 0x02, g2, g3)
MOVE_SHORTCHUNK(o1, o0, 0x00, g2, g3)
short_table_end:
EXT(84b, short_table_end, 55f)
be 1f
nop
EX(ldub [%o1], %g2, add %g0, 1)
EX(stb %g2, [%o0], add %g0, 1)
1:
retl
clr %o0
short_aligned_end:
bne short_end
andcc %o2, 8, %g0
be 1f
andcc %o2, 4, %g0
EXO2(ld [%o1 + 0x00], %g2)
EXO2(ld [%o1 + 0x04], %g3)
add %o1, 8, %o1
EXO2(st %g2, [%o0 + 0x00])
EX(st %g3, [%o0 + 0x04], sub %o2, 4)
add %o0, 8, %o0
1:
b copy_user_last7
mov %o2, %g1
.section .fixup,#alloc,#execinstr
.align 4
97:
mov %o2, %g3
fixupretl:
sethi %hi(PAGE_OFFSET), %g1
cmp %o0, %g1
blu 1f
cmp %o1, %g1
bgeu 1f
ld [%g6 + TI_PREEMPT], %g1
cmp %g1, 0
bne 1f
nop
save %sp, -64, %sp
mov %i0, %o0
call __bzero
mov %g3, %o1
restore
1: retl
mov %g3, %o0
/* exception routine sets %g2 to (broken_insn - first_insn)>>2 */
50:
/* This magic counts how many bytes are left when crash in MOVE_BIGCHUNK
* happens. This is derived from the amount ldd reads, st stores, etc.
* x = g2 % 12;
* g3 = g1 + g7 - ((g2 / 12) * 32 + (x < 4) ? 0 : (x - 4) * 4);
* o0 += (g2 / 12) * 32;
*/
cmp %g2, 12
add %o0, %g7, %o0
bcs 1f
cmp %g2, 24
bcs 2f
cmp %g2, 36
bcs 3f
nop
sub %g2, 12, %g2
sub %g7, 32, %g7
3: sub %g2, 12, %g2
sub %g7, 32, %g7
2: sub %g2, 12, %g2
sub %g7, 32, %g7
1: cmp %g2, 4
bcs,a 60f
clr %g2
sub %g2, 4, %g2
sll %g2, 2, %g2
60: and %g1, 0x7f, %g3
sub %o0, %g7, %o0
add %g3, %g7, %g3
ba fixupretl
sub %g3, %g2, %g3
51:
/* i = 41 - g2; j = i % 6;
* g3 = (g1 & 15) + (i / 6) * 16 + (j < 4) ? (j + 1) * 4 : 16;
* o0 -= (i / 6) * 16 + 16;
*/
neg %g2
and %g1, 0xf, %g1
add %g2, 41, %g2
add %o0, %g1, %o0
1: cmp %g2, 6
bcs,a 2f
cmp %g2, 4
add %g1, 16, %g1
b 1b
sub %g2, 6, %g2
2: bcc,a 2f
mov 16, %g2
inc %g2
sll %g2, 2, %g2
2: add %g1, %g2, %g3
ba fixupretl
sub %o0, %g3, %o0
52:
/* g3 = g1 + g7 - (g2 / 8) * 32 + (g2 & 4) ? (g2 & 3) * 8 : 0;
o0 += (g2 / 8) * 32 */
andn %g2, 7, %g4
add %o0, %g7, %o0
andcc %g2, 4, %g0
and %g2, 3, %g2
sll %g4, 2, %g4
sll %g2, 3, %g2
bne 60b
sub %g7, %g4, %g7
ba 60b
clr %g2
53:
/* g3 = o3 + (o2 & 15) - (g2 & 8) - (g2 & 4) ? (g2 & 3) * 2 : 0;
o0 += (g2 & 8) */
and %g2, 3, %g4
andcc %g2, 4, %g0
and %g2, 8, %g2
sll %g4, 1, %g4
be 1f
add %o0, %g2, %o0
add %g2, %g4, %g2
1: and %o2, 0xf, %g3
add %g3, %o3, %g3
ba fixupretl
sub %g3, %g2, %g3
54:
/* g3 = o3 + (o2 & 15) - (g2 / 4) * 2 - (g2 & 2) ? (g2 & 1) : 0;
o0 += (g2 / 4) * 2 */
srl %g2, 2, %o4
and %g2, 1, %o5
srl %g2, 1, %g2
add %o4, %o4, %o4
and %o5, %g2, %o5
and %o2, 0xf, %o2
add %o0, %o4, %o0
sub %o3, %o5, %o3
sub %o2, %o4, %o2
ba fixupretl
add %o2, %o3, %g3
55:
/* i = 27 - g2;
g3 = (o2 & 1) + i / 4 * 2 + !(i & 3);
o0 -= i / 4 * 2 + 1 */
neg %g2
and %o2, 1, %o2
add %g2, 27, %g2
srl %g2, 2, %o5
andcc %g2, 3, %g0
mov 1, %g2
add %o5, %o5, %o5
be,a 1f
clr %g2
1: add %g2, %o5, %g3
sub %o0, %g3, %o0
ba fixupretl
add %g3, %o2, %g3
.globl __copy_user_end
__copy_user_end:
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