1/* 2 * Copyright 2011 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 { movei r1, -EFAULT; move r0, zero } 26 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 r1 37 * on success, with the value in r0; or else -EFAULT in r1. 38 */ 39#define __get_user_N(bytes, LOAD) \ 40 STD_ENTRY(__get_user_##bytes); \ 411: { LOAD r0, r0; move r1, zero }; \ 42 jrp lr; \ 43 STD_ENDPROC(__get_user_##bytes); \ 44 .pushsection __ex_table,"a"; \ 45 .quad 1b, get_user_fault; \ 46 .popsection 47 48__get_user_N(1, ld1u) 49__get_user_N(2, ld2u) 50__get_user_N(4, ld4u) 51__get_user_N(8, ld) 52 53/* 54 * __put_user_N functions take a value in r0 and a pointer in r1, 55 * and return 0 in r0 on success or -EFAULT on failure. 56 */ 57#define __put_user_N(bytes, STORE) \ 58 STD_ENTRY(__put_user_##bytes); \ 591: { STORE r1, r0; move r0, zero }; \ 60 jrp lr; \ 61 STD_ENDPROC(__put_user_##bytes); \ 62 .pushsection __ex_table,"a"; \ 63 .quad 1b, put_user_fault; \ 64 .popsection 65 66__put_user_N(1, st1) 67__put_user_N(2, st2) 68__put_user_N(4, st4) 69__put_user_N(8, st) 70 71/* 72 * strnlen_user_asm takes the pointer in r0, and the length bound in r1. 73 * It returns the length, including the terminating NUL, or zero on exception. 74 * If length is greater than the bound, returns one plus the bound. 75 */ 76STD_ENTRY(strnlen_user_asm) 77 { beqz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */ 781: { ld1u r4, r0; addi r1, r1, -1 } 79 beqz r4, 2f 80 { bnezt r1, 1b; addi r0, r0, 1 } 812: { sub r0, r0, r3; jrp lr } 82 STD_ENDPROC(strnlen_user_asm) 83 .pushsection .fixup,"ax" 84strnlen_user_fault: 85 { move r0, zero; jrp lr } 86 ENDPROC(strnlen_user_fault) 87 .section __ex_table,"a" 88 .quad 1b, strnlen_user_fault 89 .popsection 90 91/* 92 * strncpy_from_user_asm takes the kernel target pointer in r0, 93 * the userspace source pointer in r1, and the length bound (including 94 * the trailing NUL) in r2. On success, it returns the string length 95 * (not including the trailing NUL), or -EFAULT on failure. 96 */ 97STD_ENTRY(strncpy_from_user_asm) 98 { beqz r2, 2f; move r3, r0 } 991: { ld1u r4, r1; addi r1, r1, 1; addi r2, r2, -1 } 100 { st1 r0, r4; addi r0, r0, 1 } 101 beqz r2, 2f 102 bnezt r4, 1b 103 addi r0, r0, -1 /* don't count the trailing NUL */ 1042: { sub r0, r0, r3; jrp lr } 105 STD_ENDPROC(strncpy_from_user_asm) 106 .pushsection .fixup,"ax" 107strncpy_from_user_fault: 108 { movei r0, -EFAULT; jrp lr } 109 ENDPROC(strncpy_from_user_fault) 110 .section __ex_table,"a" 111 .quad 1b, strncpy_from_user_fault 112 .popsection 113 114/* 115 * clear_user_asm takes the user target address in r0 and the 116 * number of bytes to zero in r1. 117 * It returns the number of uncopiable bytes (hopefully zero) in r0. 118 * Note that we don't use a separate .fixup section here since we fall 119 * through into the "fixup" code as the last straight-line bundle anyway. 120 */ 121STD_ENTRY(clear_user_asm) 122 { beqz r1, 2f; or r2, r0, r1 } 123 andi r2, r2, 7 124 beqzt r2, .Lclear_aligned_user_asm 1251: { st1 r0, zero; addi r0, r0, 1; addi r1, r1, -1 } 126 bnezt r1, 1b 1272: { move r0, r1; jrp lr } 128 .pushsection __ex_table,"a" 129 .quad 1b, 2b 130 .popsection 131 132.Lclear_aligned_user_asm: 1331: { st r0, zero; addi r0, r0, 8; addi r1, r1, -8 } 134 bnezt r1, 1b 1352: { move r0, r1; jrp lr } 136 STD_ENDPROC(clear_user_asm) 137 .pushsection __ex_table,"a" 138 .quad 1b, 2b 139 .popsection 140 141/* 142 * flush_user_asm takes the user target address in r0 and the 143 * number of bytes to flush in r1. 144 * It returns the number of unflushable bytes (hopefully zero) in r0. 145 */ 146STD_ENTRY(flush_user_asm) 147 beqz r1, 2f 148 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 149 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 150 { and r0, r0, r2; and r1, r1, r2 } 151 { sub r1, r1, r0 } 1521: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() } 153 { addi r0, r0, CHIP_FLUSH_STRIDE(); bnezt r1, 1b } 1542: { move r0, r1; jrp lr } 155 STD_ENDPROC(flush_user_asm) 156 .pushsection __ex_table,"a" 157 .quad 1b, 2b 158 .popsection 159 160/* 161 * inv_user_asm takes the user target address in r0 and the 162 * number of bytes to invalidate in r1. 163 * It returns the number of not inv'able bytes (hopefully zero) in r0. 164 */ 165STD_ENTRY(inv_user_asm) 166 beqz r1, 2f 167 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 168 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 169 { and r0, r0, r2; and r1, r1, r2 } 170 { sub r1, r1, r0 } 1711: { inv r0; addi r1, r1, -CHIP_INV_STRIDE() } 172 { addi r0, r0, CHIP_INV_STRIDE(); bnezt r1, 1b } 1732: { move r0, r1; jrp lr } 174 STD_ENDPROC(inv_user_asm) 175 .pushsection __ex_table,"a" 176 .quad 1b, 2b 177 .popsection 178 179/* 180 * finv_user_asm takes the user target address in r0 and the 181 * number of bytes to flush-invalidate in r1. 182 * It returns the number of not finv'able bytes (hopefully zero) in r0. 183 */ 184STD_ENTRY(finv_user_asm) 185 beqz r1, 2f 186 { movei r2, L2_CACHE_BYTES; add r1, r0, r1 } 187 { sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 } 188 { and r0, r0, r2; and r1, r1, r2 } 189 { sub r1, r1, r0 } 1901: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() } 191 { addi r0, r0, CHIP_FINV_STRIDE(); bnezt r1, 1b } 1922: { move r0, r1; jrp lr } 193 STD_ENDPROC(finv_user_asm) 194 .pushsection __ex_table,"a" 195 .quad 1b, 2b 196 .popsection 197