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linux/arch/sh/mm/copy_page.S
Paul Mundt 510c72ad2d sh: Fixup various PAGE_SIZE == 4096 assumptions. 
There were a number of places that made evil PAGE_SIZE == 4k
assumptions that ended up breaking when trying to play with
8k and 64k page sizes, this fixes those up.

The most significant change is the way we load THREAD_SIZE,
previously this was done via:

	mov	#(THREAD_SIZE >> 8), reg
	shll8	reg

to avoid a memory access and allow the immediate load. With
a 64k PAGE_SIZE, we're out of range for the immediate load
size without resorting to special instructions available in
later ISAs (movi20s and so on). The "workaround" for this is
to bump up the shift to 10 and insert a shll2, which gives a
bit more flexibility while still being much cheaper than a
memory access.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2006-12-06 10:45:39 +09:00

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6.0 KiB
ArmAsm
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/*
* copy_page, __copy_user_page, __copy_user implementation of SuperH
*
* Copyright (C) 2001 Niibe Yutaka & Kaz Kojima
* Copyright (C) 2002 Toshinobu Sugioka
* Copyright (C) 2006 Paul Mundt
*/
#include <linux/linkage.h>
#include <asm/page.h>
/*
* copy_page_slow
* @to: P1 address
* @from: P1 address
*
* void copy_page_slow(void *to, void *from)
*/
/*
* r0, r1, r2, r3, r4, r5, r6, r7 --- scratch
* r8 --- from + PAGE_SIZE
* r9 --- not used
* r10 --- to
* r11 --- from
*/
ENTRY(copy_page_slow)
mov.l r8,@-r15
mov.l r10,@-r15
mov.l r11,@-r15
mov r4,r10
mov r5,r11
mov r5,r8
mov.l .Lpsz,r0
add r0,r8
!
1: mov.l @r11+,r0
mov.l @r11+,r1
mov.l @r11+,r2
mov.l @r11+,r3
mov.l @r11+,r4
mov.l @r11+,r5
mov.l @r11+,r6
mov.l @r11+,r7
#if defined(CONFIG_CPU_SH3)
mov.l r0,@r10
#elif defined(CONFIG_CPU_SH4)
movca.l r0,@r10
mov r10,r0
#endif
add #32,r10
mov.l r7,@-r10
mov.l r6,@-r10
mov.l r5,@-r10
mov.l r4,@-r10
mov.l r3,@-r10
mov.l r2,@-r10
mov.l r1,@-r10
#if defined(CONFIG_CPU_SH4)
ocbwb @r0
#endif
cmp/eq r11,r8
bf/s 1b
add #28,r10
!
mov.l @r15+,r11
mov.l @r15+,r10
mov.l @r15+,r8
rts
nop
#if defined(CONFIG_CPU_SH4)
/*
* __copy_user_page
* @to: P1 address (with same color)
* @from: P1 address
* @orig_to: P1 address
*
* void __copy_user_page(void *to, void *from, void *orig_to)
*/
/*
* r0, r1, r2, r3, r4, r5, r6, r7 --- scratch
* r8 --- from + PAGE_SIZE
* r9 --- orig_to
* r10 --- to
* r11 --- from
*/
ENTRY(__copy_user_page)
mov.l r8,@-r15
mov.l r9,@-r15
mov.l r10,@-r15
mov.l r11,@-r15
mov r4,r10
mov r5,r11
mov r6,r9
mov r5,r8
mov.l .Lpsz,r0
add r0,r8
!
1: ocbi @r9
add #32,r9
mov.l @r11+,r0
mov.l @r11+,r1
mov.l @r11+,r2
mov.l @r11+,r3
mov.l @r11+,r4
mov.l @r11+,r5
mov.l @r11+,r6
mov.l @r11+,r7
movca.l r0,@r10
mov r10,r0
add #32,r10
mov.l r7,@-r10
mov.l r6,@-r10
mov.l r5,@-r10
mov.l r4,@-r10
mov.l r3,@-r10
mov.l r2,@-r10
mov.l r1,@-r10
ocbwb @r0
cmp/eq r11,r8
bf/s 1b
add #28,r10
!
mov.l @r15+,r11
mov.l @r15+,r10
mov.l @r15+,r9
mov.l @r15+,r8
rts
nop
#endif
.Lpsz: .long PAGE_SIZE
/*
* __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
* Return the number of bytes NOT copied
*/
#define EX(...) \
9999: __VA_ARGS__ ; \
.section __ex_table, "a"; \
.long 9999b, 6000f ; \
.previous
ENTRY(__copy_user)
tst r6,r6 ! Check explicitly for zero
bf 1f
rts
mov #0,r0 ! normal return
1:
mov.l r10,@-r15
mov.l r9,@-r15
mov.l r8,@-r15
mov r4,r3
add r6,r3 ! last destination address
mov #12,r0 ! Check if small number of bytes
cmp/gt r0,r6
bt 2f
bra .L_cleanup_loop
nop
2:
neg r5,r0 ! Calculate bytes needed to align source
add #4,r0
and #3,r0
tst r0,r0
bt .L_jump
mov r0,r1
.L_loop1:
! Copy bytes to align source
EX( mov.b @r5+,r0 )
dt r1
EX( mov.b r0,@r4 )
add #-1,r6
bf/s .L_loop1
add #1,r4
.L_jump:
mov r6,r2 ! Calculate number of longwords to copy
shlr2 r2
tst r2,r2
bt .L_cleanup
mov r4,r0 ! Jump to appropriate routine
and #3,r0
mov r0,r1
shll2 r1
mova .L_jump_tbl,r0
mov.l @(r0,r1),r1
jmp @r1
nop
.align 2
.L_jump_tbl:
.long .L_dest00
.long .L_dest01
.long .L_dest10
.long .L_dest11
! Destination = 00
.L_dest00:
mov r2,r7
shlr2 r7
shlr r7
tst r7,r7
mov #7,r0
bt/s 1f
and r0,r2
.align 2
2:
EX( mov.l @r5+,r0 )
EX( mov.l @r5+,r8 )
EX( mov.l @r5+,r9 )
EX( mov.l @r5+,r10 )
EX( mov.l r0,@r4 )
EX( mov.l r8,@(4,r4) )
EX( mov.l r9,@(8,r4) )
EX( mov.l r10,@(12,r4) )
EX( mov.l @r5+,r0 )
EX( mov.l @r5+,r8 )
EX( mov.l @r5+,r9 )
EX( mov.l @r5+,r10 )
dt r7
EX( mov.l r0,@(16,r4) )
EX( mov.l r8,@(20,r4) )
EX( mov.l r9,@(24,r4) )
EX( mov.l r10,@(28,r4) )
bf/s 2b
add #32,r4
tst r2,r2
bt .L_cleanup
1:
EX( mov.l @r5+,r0 )
dt r2
EX( mov.l r0,@r4 )
bf/s 1b
add #4,r4
bra .L_cleanup
nop
! Destination = 10
.L_dest10:
mov r2,r7
shlr2 r7
shlr r7
tst r7,r7
mov #7,r0
bt/s 1f
and r0,r2
2:
dt r7
#ifdef __LITTLE_ENDIAN__
EX( mov.l @r5+,r0 )
EX( mov.l @r5+,r1 )
EX( mov.l @r5+,r8 )
EX( mov.l @r5+,r9 )
EX( mov.l @r5+,r10 )
EX( mov.w r0,@r4 )
add #2,r4
xtrct r1,r0
xtrct r8,r1
xtrct r9,r8
xtrct r10,r9
EX( mov.l r0,@r4 )
EX( mov.l r1,@(4,r4) )
EX( mov.l r8,@(8,r4) )
EX( mov.l r9,@(12,r4) )
EX( mov.l @r5+,r1 )
EX( mov.l @r5+,r8 )
EX( mov.l @r5+,r0 )
xtrct r1,r10
xtrct r8,r1
xtrct r0,r8
shlr16 r0
EX( mov.l r10,@(16,r4) )
EX( mov.l r1,@(20,r4) )
EX( mov.l r8,@(24,r4) )
EX( mov.w r0,@(28,r4) )
bf/s 2b
add #30,r4
#else
EX( mov.l @(28,r5),r0 )
EX( mov.l @(24,r5),r8 )
EX( mov.l @(20,r5),r9 )
EX( mov.l @(16,r5),r10 )
EX( mov.w r0,@(30,r4) )
add #-2,r4
xtrct r8,r0
xtrct r9,r8
xtrct r10,r9
EX( mov.l r0,@(28,r4) )
EX( mov.l r8,@(24,r4) )
EX( mov.l r9,@(20,r4) )
EX( mov.l @(12,r5),r0 )
EX( mov.l @(8,r5),r8 )
xtrct r0,r10
EX( mov.l @(4,r5),r9 )
mov.l r10,@(16,r4)
EX( mov.l @r5,r10 )
xtrct r8,r0
xtrct r9,r8
xtrct r10,r9
EX( mov.l r0,@(12,r4) )
EX( mov.l r8,@(8,r4) )
swap.w r10,r0
EX( mov.l r9,@(4,r4) )
EX( mov.w r0,@(2,r4) )
add #32,r5
bf/s 2b
add #34,r4
#endif
tst r2,r2
bt .L_cleanup
1: ! Read longword, write two words per iteration
EX( mov.l @r5+,r0 )
dt r2
#ifdef __LITTLE_ENDIAN__
EX( mov.w r0,@r4 )
shlr16 r0
EX( mov.w r0,@(2,r4) )
#else
EX( mov.w r0,@(2,r4) )
shlr16 r0
EX( mov.w r0,@r4 )
#endif
bf/s 1b
add #4,r4
bra .L_cleanup
nop
! Destination = 01 or 11
.L_dest01:
.L_dest11:
! Read longword, write byte, word, byte per iteration
EX( mov.l @r5+,r0 )
dt r2
#ifdef __LITTLE_ENDIAN__
EX( mov.b r0,@r4 )
shlr8 r0
add #1,r4
EX( mov.w r0,@r4 )
shlr16 r0
EX( mov.b r0,@(2,r4) )
bf/s .L_dest01
add #3,r4
#else
EX( mov.b r0,@(3,r4) )
shlr8 r0
swap.w r0,r7
EX( mov.b r7,@r4 )
add #1,r4
EX( mov.w r0,@r4 )
bf/s .L_dest01
add #3,r4
#endif
! Cleanup last few bytes
.L_cleanup:
mov r6,r0
and #3,r0
tst r0,r0
bt .L_exit
mov r0,r6
.L_cleanup_loop:
EX( mov.b @r5+,r0 )
dt r6
EX( mov.b r0,@r4 )
bf/s .L_cleanup_loop
add #1,r4
.L_exit:
mov #0,r0 ! normal return
5000:
# Exception handler:
.section .fixup, "ax"
6000:
mov.l 8000f,r1
mov r3,r0
jmp @r1
sub r4,r0
.align 2
8000: .long 5000b
.previous
mov.l @r15+,r8
mov.l @r15+,r9
rts
mov.l @r15+,r10
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