/* * 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.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_SH4) movca.l r0,@r10 mov r10,r0 #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 #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 .balign 4 .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) ! 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( mov.b @r5+,r0 ) dt r6 EX( mov.b r0,@r4 ) bf/s 2b add #1,r4 1: 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 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