1/* 2 * Copyright 2010 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 */ 14 15#include <linux/linkage.h> 16#include <asm/errno.h> 17#include <asm/cache.h> 18#include <arch/chip.h> 19 20/* Access user memory, but use MMU to avoid propagating kernel exceptions. */ 21 22 .pushsection .fixup,"ax" 23 24get_user_fault: 25 { move r0, zero; move r1, zero } 26 { movei r2, -EFAULT; jrp lr } 27 ENDPROC(get_user_fault) 28 29put_user_fault: 30 { movei r0, -EFAULT; jrp lr } 31 ENDPROC(put_user_fault) 32 33 .popsection 34 35/* 36 * __get_user_N functions take a pointer in r0, and return 0 in r2 37 * on success, with the value in r0; or else -EFAULT in r2. 38 */ 39#define __get_user_N(bytes, LOAD) \ 40 STD_ENTRY(__get_user_##bytes); \ 411: { LOAD r0, r0; move r1, zero; move r2, zero }; \ 42 jrp lr; \ 43 STD_ENDPROC(__get_user_##bytes); \ 44 .pushsection __ex_table,"a"; \ 45 .word 1b, get_user_fault; \ 46 .popsection 47 48__get_user_N(1, lb_u) 49__get_user_N(2, lh_u) 50__get_user_N(4, lw) 51 52/* 53 * __get_user_8 takes a pointer in r0, and returns 0 in r2 54 * on success, with the value in r0/r1; or else -EFAULT in r2. 55 */ 56 STD_ENTRY(__get_user_8); 571: { lw r0, r0; addi r1, r0, 4 }; 582: { lw r1, r1; move r2, zero }; 59 jrp lr; 60 STD_ENDPROC(__get_user_8); 61 .pushsection __ex_table,"a"; 62 .word 1b, get_user_fault; 63 .word 2b, get_user_fault; 64 .popsection 65 66/* 67 * __put_user_N functions take a value in r0 and a pointer in r1, 68 * and return 0 in r0 on success or -EFAULT on failure. 69 */ 70#define __put_user_N(bytes, STORE) \ 71 STD_ENTRY(__put_user_##bytes); \ 721: { STORE r1, r0; move r0, zero }; \ 73 jrp lr; \ 74 STD_ENDPROC(__put_user_##bytes); \ 75 .pushsection __ex_table,"a"; \ 76 .word 1b, put_user_fault; \ 77 .popsection 78 79__put_user_N(1, sb) 80__put_user_N(2, sh) 81__put_user_N(4, sw) 82 83/* 84 * __put_user_8 takes a value in r0/r1 and a pointer in r2, 85 * and returns 0 in r0 on success or -EFAULT on failure. 86 */ 87STD_ENTRY(__put_user_8) 881: { sw r2, r0; addi r2, r2, 4 } 892: { sw r2, r1; move r0, zero } 90 jrp lr 91 STD_ENDPROC(__put_user_8) 92 .pushsection __ex_table,"a" 93 .word 1b, put_user_fault 94 .word 2b, put_user_fault 95 .popsection 96 97 98/* 99 * strnlen_user_asm takes the pointer in r0, and the length bound in r1. 100 * It returns the length, including the terminating NUL, or zero on exception. 101 * If length is greater than the bound, returns one plus the bound. 102 */ 103STD_ENTRY(strnlen_user_asm) 104 { bz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */ 1051: { lb_u r4, r0; addi r1, r1, -1 } 106 bz r4, 2f 107 { bnzt r1, 1b; addi r0, r0, 1 } 1082: { sub r0, r0, r3; jrp lr } 109 STD_ENDPROC(strnlen_user_asm) 110 .pushsection .fixup,"ax" 111strnlen_user_fault: 112 { move r0, zero; jrp lr } 113 ENDPROC(strnlen_user_fault) 114 .section __ex_table,"a" 115 .word 1b, strnlen_user_fault 116 .popsection 117 118/* 119 * strncpy_from_user_asm takes the kernel target pointer in r0, 120 * the userspace source pointer in r1, and the length bound (including 121 * the trailing NUL) in r2. On success, it returns the string length 122 * (not including the trailing NUL), or -EFAULT on failure. 123 */ 124STD_ENTRY(strncpy_from_user_asm) 125 { bz r2, 2f; move r3, r0 } 1261: { lb_u r4, r1; addi r1, r1, 1; addi r2, r2, -1 } 127 { sb r0, r4; addi r0, r0, 1 } 128 bz r2, 2f 129 bnzt r4, 1b 130 addi r0, r0, -1 /* don't count the trailing NUL */ 1312: { sub r0, r0, r3; jrp lr } 132 STD_ENDPROC(strncpy_from_user_asm) 133 .pushsection .fixup,"ax" 134strncpy_from_user_fault: 135 { movei r0, -EFAULT; jrp lr } 136 ENDPROC(strncpy_from_user_fault) 137 .section __ex_table,"a" 138 .word 1b, strncpy_from_user_fault 139 .popsection 140 141/* 142 * clear_user_asm takes the user target address in r0 and the 143 * number of bytes to zero in r1. 144 * It returns the number of uncopiable bytes (hopefully zero) in r0. 145 * Note that we don't use a separate .fixup section here since we fall 146 * through into the "fixup" code as the last straight-line bundle anyway. 147 */ 148STD_ENTRY(clear_user_asm) 149 { bz r1, 2f; or r2, r0, r1 } 150 andi r2, r2, 3 151 bzt r2, .Lclear_aligned_user_asm 1521: { sb r0, zero; addi r0, r0, 1; addi r1, r1, -1 } 153 bnzt r1, 1b 1542: { move r0, r1; jrp lr } 155 .pushsection __ex_table,"a" 156 .word 1b, 2b 157 .popsection 158 159.Lclear_aligned_user_asm: 1601: { sw r0, zero; addi r0, r0, 4; addi r1, r1, -4 } 161 bnzt r1, 1b 1622: { move r0, r1; jrp lr } 163 STD_ENDPROC(clear_user_asm) 164 .pushsection __ex_table,"a" 165 .word 1b, 2b 166 .popsection 167 168/* 169 * flush_user_asm takes the user target address in r0 and the 170 * number of bytes to flush in r1. 171 * It returns the number of unflushable bytes (hopefully zero) in r0. 172 */ 173STD_ENTRY(flush_user_asm) 174 bz r1, 2f 175 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 176 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 177 { and r0, r0, r2; and r1, r1, r2 } 178 { sub r1, r1, r0 } 1791: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() } 180 { addi r0, r0, CHIP_FLUSH_STRIDE(); bnzt r1, 1b } 1812: { move r0, r1; jrp lr } 182 STD_ENDPROC(flush_user_asm) 183 .pushsection __ex_table,"a" 184 .word 1b, 2b 185 .popsection 186 187/* 188 * inv_user_asm takes the user target address in r0 and the 189 * number of bytes to invalidate in r1. 190 * It returns the number of not inv'able bytes (hopefully zero) in r0. 191 */ 192STD_ENTRY(inv_user_asm) 193 bz r1, 2f 194 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 195 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 196 { and r0, r0, r2; and r1, r1, r2 } 197 { sub r1, r1, r0 } 1981: { inv r0; addi r1, r1, -CHIP_INV_STRIDE() } 199 { addi r0, r0, CHIP_INV_STRIDE(); bnzt r1, 1b } 2002: { move r0, r1; jrp lr } 201 STD_ENDPROC(inv_user_asm) 202 .pushsection __ex_table,"a" 203 .word 1b, 2b 204 .popsection 205 206/* 207 * finv_user_asm takes the user target address in r0 and the 208 * number of bytes to flush-invalidate in r1. 209 * It returns the number of not finv'able bytes (hopefully zero) in r0. 210 */ 211STD_ENTRY(finv_user_asm) 212 bz r1, 2f 213 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 214 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 215 { and r0, r0, r2; and r1, r1, r2 } 216 { sub r1, r1, r0 } 2171: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() } 218 { addi r0, r0, CHIP_FINV_STRIDE(); bnzt r1, 1b } 2192: { move r0, r1; jrp lr } 220 STD_ENDPROC(finv_user_asm) 221 .pushsection __ex_table,"a" 222 .word 1b, 2b 223 .popsection 224