diff options
Diffstat (limited to '')
-rw-r--r-- | arch/sh/lib/copy_page.S | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/arch/sh/lib/copy_page.S b/arch/sh/lib/copy_page.S new file mode 100644 index 0000000000..d4e9d18cee --- /dev/null +++ b/arch/sh/lib/copy_page.S @@ -0,0 +1,390 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * 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 + * @to: P1 address + * @from: P1 address + * + * void copy_page(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) + mov.l r8,@-r15 + mov.l r10,@-r15 + mov.l r11,@-r15 + mov r4,r10 + mov r5,r11 + mov r5,r8 + mov #(PAGE_SIZE >> 10), r0 + shll8 r0 + shll2 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_SH4) + movca.l r0,@r10 +#else + mov.l r0,@r10 +#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 + cmp/eq r11,r8 + bf/s 1b + add #28,r10 + ! + mov.l @r15+,r11 + mov.l @r15+,r10 + mov.l @r15+,r8 + rts + nop + +/* + * __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 +#define EX_NO_POP(...) \ + 9999: __VA_ARGS__ ; \ + .section __ex_table, "a"; \ + .long 9999b, 6005f ; \ + .previous +ENTRY(__copy_user) + ! Check if small number of bytes + mov #11,r0 + mov r4,r3 + cmp/gt r0,r6 ! r6 (len) > r0 (11) + bf/s .L_cleanup_loop_no_pop + add r6,r3 ! last destination address + + ! Calculate bytes needed to align to src + mov.l r11,@-r15 + neg r5,r0 + mov.l r10,@-r15 + add #4,r0 + mov.l r9,@-r15 + and #3,r0 + mov.l r8,@-r15 + tst r0,r0 + bt 2f + +1: + ! Copy bytes to long word align src +EX( mov.b @r5+,r1 ) + dt r0 + add #-1,r6 +EX( mov.b r1,@r4 ) + bf/s 1b + add #1,r4 + + ! Jump to appropriate routine depending on dest +2: mov #3,r1 + mov r6, r2 + and r4,r1 + shlr2 r2 + 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 + +/* + * Come here if there are less than 12 bytes to copy + * + * Keep the branch target close, so the bf/s callee doesn't overflow + * and result in a more expensive branch being inserted. This is the + * fast-path for small copies, the jump via the jump table will hit the + * default slow-path cleanup. -PFM. + */ +.L_cleanup_loop_no_pop: + tst r6,r6 ! Check explicitly for zero + bt 1f + +2: +EX_NO_POP( mov.b @r5+,r0 ) + dt r6 +EX_NO_POP( mov.b r0,@r4 ) + bf/s 2b + add #1,r4 + +1: mov #0,r0 ! normal return +5000: + +# Exception handler: +.section .fixup, "ax" +6005: + mov.l 8000f,r1 + mov r3,r0 + jmp @r1 + sub r4,r0 + .align 2 +8000: .long 5000b + +.previous + rts + nop + +! Destination = 00 + +.L_dest00: + ! Skip the large copy for small transfers + mov #(32+32-4), r0 + cmp/gt r6, r0 ! r0 (60) > r6 (len) + bt 1f + + ! Align dest to a 32 byte boundary + neg r4,r0 + add #0x20, r0 + and #0x1f, r0 + tst r0, r0 + bt 2f + + sub r0, r6 + shlr2 r0 +3: +EX( mov.l @r5+,r1 ) + dt r0 +EX( mov.l r1,@r4 ) + bf/s 3b + add #4,r4 + +2: +EX( mov.l @r5+,r0 ) +EX( mov.l @r5+,r1 ) +EX( mov.l @r5+,r2 ) +EX( mov.l @r5+,r7 ) +EX( mov.l @r5+,r8 ) +EX( mov.l @r5+,r9 ) +EX( mov.l @r5+,r10 ) +EX( mov.l @r5+,r11 ) +#ifdef CONFIG_CPU_SH4 +EX( movca.l r0,@r4 ) +#else +EX( mov.l r0,@r4 ) +#endif + add #-32, r6 +EX( mov.l r1,@(4,r4) ) + mov #32, r0 +EX( mov.l r2,@(8,r4) ) + cmp/gt r6, r0 ! r0 (32) > r6 (len) +EX( mov.l r7,@(12,r4) ) +EX( mov.l r8,@(16,r4) ) +EX( mov.l r9,@(20,r4) ) +EX( mov.l r10,@(24,r4) ) +EX( mov.l r11,@(28,r4) ) + bf/s 2b + add #32,r4 + +1: mov r6, r0 + shlr2 r0 + tst r0, r0 + bt .L_cleanup +1: +EX( mov.l @r5+,r1 ) + dt r0 +EX( mov.l r1,@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 CONFIG_CPU_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 CONFIG_CPU_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 CONFIG_CPU_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 + mov.l @r15+,r10 + rts + mov.l @r15+,r11 |