1 /* 2 * Copyright (C) 2009 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2009 PetaLogix 4 * Copyright (C) 2007 LynuxWorks, Inc. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/linkage.h> 13 #include <asm/page.h> 14 15 /* Loop unrolling for __copy_tofrom_user */ 16 #define COPY(offset) \ 17 1: lwi r4 , r6, 0x0000 + offset; \ 18 2: lwi r19, r6, 0x0004 + offset; \ 19 3: lwi r20, r6, 0x0008 + offset; \ 20 4: lwi r21, r6, 0x000C + offset; \ 21 5: lwi r22, r6, 0x0010 + offset; \ 22 6: lwi r23, r6, 0x0014 + offset; \ 23 7: lwi r24, r6, 0x0018 + offset; \ 24 8: lwi r25, r6, 0x001C + offset; \ 25 9: swi r4 , r5, 0x0000 + offset; \ 26 10: swi r19, r5, 0x0004 + offset; \ 27 11: swi r20, r5, 0x0008 + offset; \ 28 12: swi r21, r5, 0x000C + offset; \ 29 13: swi r22, r5, 0x0010 + offset; \ 30 14: swi r23, r5, 0x0014 + offset; \ 31 15: swi r24, r5, 0x0018 + offset; \ 32 16: swi r25, r5, 0x001C + offset; \ 33 .section __ex_table,"a"; \ 34 .word 1b, 33f; \ 35 .word 2b, 33f; \ 36 .word 3b, 33f; \ 37 .word 4b, 33f; \ 38 .word 5b, 33f; \ 39 .word 6b, 33f; \ 40 .word 7b, 33f; \ 41 .word 8b, 33f; \ 42 .word 9b, 33f; \ 43 .word 10b, 33f; \ 44 .word 11b, 33f; \ 45 .word 12b, 33f; \ 46 .word 13b, 33f; \ 47 .word 14b, 33f; \ 48 .word 15b, 33f; \ 49 .word 16b, 33f; \ 50 .text 51 52 #define COPY_80(offset) \ 53 COPY(0x00 + offset);\ 54 COPY(0x20 + offset);\ 55 COPY(0x40 + offset);\ 56 COPY(0x60 + offset); 57 58 /* 59 * int __copy_tofrom_user(char *to, char *from, int len) 60 * Return: 61 * 0 on success 62 * number of not copied bytes on error 63 */ 64 .text 65 .globl __copy_tofrom_user; 66 .type __copy_tofrom_user, @function 67 .align 4; 68 __copy_tofrom_user: 69 /* 70 * r5 - to 71 * r6 - from 72 * r7, r3 - count 73 * r4 - tempval 74 */ 75 beqid r7, 0f /* zero size is not likely */ 76 or r3, r5, r6 /* find if is any to/from unaligned */ 77 or r3, r3, r7 /* find if count is unaligned */ 78 andi r3, r3, 0x3 /* mask last 3 bits */ 79 bneid r3, bu1 /* if r3 is not zero then byte copying */ 80 or r3, r0, r0 81 82 rsubi r3, r7, PAGE_SIZE /* detect PAGE_SIZE */ 83 beqid r3, page; 84 or r3, r0, r0 85 86 w1: lw r4, r6, r3 /* at least one 4 byte copy */ 87 w2: sw r4, r5, r3 88 addik r7, r7, -4 89 bneid r7, w1 90 addik r3, r3, 4 91 addik r3, r7, 0 92 rtsd r15, 8 93 nop 94 95 .section __ex_table,"a" 96 .word w1, 0f; 97 .word w2, 0f; 98 .text 99 100 .align 4 /* Alignment is important to keep icache happy */ 101 page: /* Create room on stack and save registers for storing values */ 102 addik r1, r1, -40 103 swi r5, r1, 0 104 swi r6, r1, 4 105 swi r7, r1, 8 106 swi r19, r1, 12 107 swi r20, r1, 16 108 swi r21, r1, 20 109 swi r22, r1, 24 110 swi r23, r1, 28 111 swi r24, r1, 32 112 swi r25, r1, 36 113 loop: /* r4, r19, r20, r21, r22, r23, r24, r25 are used for storing values */ 114 /* Loop unrolling to get performance boost */ 115 COPY_80(0x000); 116 COPY_80(0x080); 117 COPY_80(0x100); 118 COPY_80(0x180); 119 /* copy loop */ 120 addik r6, r6, 0x200 121 addik r7, r7, -0x200 122 bneid r7, loop 123 addik r5, r5, 0x200 124 125 /* Restore register content */ 126 lwi r5, r1, 0 127 lwi r6, r1, 4 128 lwi r7, r1, 8 129 lwi r19, r1, 12 130 lwi r20, r1, 16 131 lwi r21, r1, 20 132 lwi r22, r1, 24 133 lwi r23, r1, 28 134 lwi r24, r1, 32 135 lwi r25, r1, 36 136 addik r1, r1, 40 137 /* return back */ 138 addik r3, r0, 0 139 rtsd r15, 8 140 nop 141 142 /* Fault case - return temp count */ 143 33: 144 addik r3, r7, 0 145 /* Restore register content */ 146 lwi r5, r1, 0 147 lwi r6, r1, 4 148 lwi r7, r1, 8 149 lwi r19, r1, 12 150 lwi r20, r1, 16 151 lwi r21, r1, 20 152 lwi r22, r1, 24 153 lwi r23, r1, 28 154 lwi r24, r1, 32 155 lwi r25, r1, 36 156 addik r1, r1, 40 157 /* return back */ 158 rtsd r15, 8 159 nop 160 161 .align 4 /* Alignment is important to keep icache happy */ 162 bu1: lbu r4,r6,r3 163 bu2: sb r4,r5,r3 164 addik r7,r7,-1 165 bneid r7,bu1 166 addik r3,r3,1 /* delay slot */ 167 0: 168 addik r3,r7,0 169 rtsd r15,8 170 nop 171 .size __copy_tofrom_user, . - __copy_tofrom_user 172 173 .section __ex_table,"a" 174 .word bu1, 0b; 175 .word bu2, 0b; 176 .text 177