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linux/arch/sparc/lib/copy_user.S
Al Viro c4da8e0dc6 sparc32: switch copy_user.S away from range exception table entries 
Those were the last range exception table entries, which will allow
to get rid of a lot of weirdness.  Emits the same code into .text.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-03 20:05:17 -05:00

395 lines
9.4 KiB
ArmAsm
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/* SPDX-License-Identifier: GPL-2.0 */
/* 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>
#include <asm/export.h>
/* Work around cpp -rob */
#define ALLOC #alloc
#define EXECINSTR #execinstr
#define EX_ENTRY(l1, l2) \
.section __ex_table,ALLOC; \
.align 4; \
.word l1, l2; \
.text;
#define EX(x,y,a,b) \
98: x,y; \
.section .fixup,ALLOC,EXECINSTR; \
.align 4; \
99: retl; \
a, b, %o0; \
EX_ENTRY(98b, 99b)
#define EX2(x,y,c,d,e,a,b) \
98: x,y; \
.section .fixup,ALLOC,EXECINSTR; \
.align 4; \
99: c, d, e; \
retl; \
a, b, %o0; \
EX_ENTRY(98b, 99b)
#define EXO2(x,y) \
98: x, y; \
EX_ENTRY(98b, 97f)
#define LD(insn, src, offset, reg, label) \
98: insn [%src + (offset)], %reg; \
.section .fixup,ALLOC,EXECINSTR; \
99: ba label; \
mov offset, %g5; \
EX_ENTRY(98b, 99b)
#define ST(insn, dst, offset, reg, label) \
98: insn %reg, [%dst + (offset)]; \
.section .fixup,ALLOC,EXECINSTR; \
99: ba label; \
mov offset, %g5; \
EX_ENTRY(98b, 99b)
/* Both these macros have to start with exactly the same insn */
/* left: g7 + (g1 % 128) - offset */
#define MOVE_BIGCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
LD(ldd, src, offset + 0x00, t0, bigchunk_fault) \
LD(ldd, src, offset + 0x08, t2, bigchunk_fault) \
LD(ldd, src, offset + 0x10, t4, bigchunk_fault) \
LD(ldd, src, offset + 0x18, t6, bigchunk_fault) \
ST(st, dst, offset + 0x00, t0, bigchunk_fault) \
ST(st, dst, offset + 0x04, t1, bigchunk_fault) \
ST(st, dst, offset + 0x08, t2, bigchunk_fault) \
ST(st, dst, offset + 0x0c, t3, bigchunk_fault) \
ST(st, dst, offset + 0x10, t4, bigchunk_fault) \
ST(st, dst, offset + 0x14, t5, bigchunk_fault) \
ST(st, dst, offset + 0x18, t6, bigchunk_fault) \
ST(st, dst, offset + 0x1c, t7, bigchunk_fault)
/* left: g7 + (g1 % 128) - offset */
#define MOVE_BIGALIGNCHUNK(src, dst, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
LD(ldd, src, offset + 0x00, t0, bigchunk_fault) \
LD(ldd, src, offset + 0x08, t2, bigchunk_fault) \
LD(ldd, src, offset + 0x10, t4, bigchunk_fault) \
LD(ldd, src, offset + 0x18, t6, bigchunk_fault) \
ST(std, dst, offset + 0x00, t0, bigchunk_fault) \
ST(std, dst, offset + 0x08, t2, bigchunk_fault) \
ST(std, dst, offset + 0x10, t4, bigchunk_fault) \
ST(std, dst, offset + 0x18, t6, bigchunk_fault)
.section .fixup,#alloc,#execinstr
bigchunk_fault:
sub %g7, %g5, %o0
and %g1, 127, %g1
retl
add %o0, %g1, %o0
/* left: offset + 16 + (g1 % 16) */
#define MOVE_LASTCHUNK(src, dst, offset, t0, t1, t2, t3) \
LD(ldd, src, -(offset + 0x10), t0, lastchunk_fault) \
LD(ldd, src, -(offset + 0x08), t2, lastchunk_fault) \
ST(st, dst, -(offset + 0x10), t0, lastchunk_fault) \
ST(st, dst, -(offset + 0x0c), t1, lastchunk_fault) \
ST(st, dst, -(offset + 0x08), t2, lastchunk_fault) \
ST(st, dst, -(offset + 0x04), t3, lastchunk_fault)
.section .fixup,#alloc,#execinstr
lastchunk_fault:
and %g1, 15, %g1
retl
sub %g1, %g5, %o0
/* left: o3 + (o2 % 16) - offset */
#define MOVE_HALFCHUNK(src, dst, offset, t0, t1, t2, t3) \
LD(lduh, src, offset + 0x00, t0, halfchunk_fault) \
LD(lduh, src, offset + 0x02, t1, halfchunk_fault) \
LD(lduh, src, offset + 0x04, t2, halfchunk_fault) \
LD(lduh, src, offset + 0x06, t3, halfchunk_fault) \
ST(sth, dst, offset + 0x00, t0, halfchunk_fault) \
ST(sth, dst, offset + 0x02, t1, halfchunk_fault) \
ST(sth, dst, offset + 0x04, t2, halfchunk_fault) \
ST(sth, dst, offset + 0x06, t3, halfchunk_fault)
/* left: o3 + (o2 % 16) + offset + 2 */
#define MOVE_SHORTCHUNK(src, dst, offset, t0, t1) \
LD(ldub, src, -(offset + 0x02), t0, halfchunk_fault) \
LD(ldub, src, -(offset + 0x01), t1, halfchunk_fault) \
ST(stb, dst, -(offset + 0x02), t0, halfchunk_fault) \
ST(stb, dst, -(offset + 0x01), t1, halfchunk_fault)
.section .fixup,#alloc,#execinstr
halfchunk_fault:
and %o2, 15, %o2
sub %o3, %g5, %o3
retl
add %o2, %o3, %o0
/* left: offset + 2 + (o2 % 2) */
#define MOVE_LAST_SHORTCHUNK(src, dst, offset, t0, t1) \
LD(ldub, src, -(offset + 0x02), t0, last_shortchunk_fault) \
LD(ldub, src, -(offset + 0x01), t1, last_shortchunk_fault) \
ST(stb, dst, -(offset + 0x02), t0, last_shortchunk_fault) \
ST(stb, dst, -(offset + 0x01), t1, last_shortchunk_fault)
.section .fixup,#alloc,#execinstr
last_shortchunk_fault:
and %o2, 1, %o2
retl
sub %o2, %g5, %o0
.text
.align 4
.globl __copy_user_begin
__copy_user_begin:
.globl __copy_user
EXPORT_SYMBOL(__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)
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
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:
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)
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)
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)
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
MOVE_LAST_SHORTCHUNK(o1, o0, 0x0c, g2, g3)
MOVE_LAST_SHORTCHUNK(o1, o0, 0x0a, g2, g3)
MOVE_LAST_SHORTCHUNK(o1, o0, 0x08, g2, g3)
MOVE_LAST_SHORTCHUNK(o1, o0, 0x06, g2, g3)
MOVE_LAST_SHORTCHUNK(o1, o0, 0x04, g2, g3)
MOVE_LAST_SHORTCHUNK(o1, o0, 0x02, g2, g3)
MOVE_LAST_SHORTCHUNK(o1, o0, 0x00, g2, g3)
short_table_end:
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:
retl
mov %o2, %o0
.globl __copy_user_end
__copy_user_end:
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