Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Unified implementation of memcpy, memmove and the __copy_user backend. |
| 7 | * |
| 8 | * Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@gnu.org) |
| 9 | * Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc. |
| 10 | * Copyright (C) 2002 Broadcom, Inc. |
| 11 | * memcpy/copy_user author: Mark Vandevoorde |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 12 | * Copyright (C) 2007 Maciej W. Rozycki |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 13 | * Copyright (C) 2014 Imagination Technologies Ltd. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | * |
| 15 | * Mnemonic names for arguments to memcpy/__copy_user |
| 16 | */ |
Ralf Baechle | e5adb87 | 2005-10-20 22:55:26 +0100 | [diff] [blame] | 17 | |
| 18 | /* |
| 19 | * Hack to resolve longstanding prefetch issue |
| 20 | * |
| 21 | * Prefetching may be fatal on some systems if we're prefetching beyond the |
| 22 | * end of memory on some systems. It's also a seriously bad idea on non |
| 23 | * dma-coherent systems. |
| 24 | */ |
Ralf Baechle | 634286f | 2009-01-28 17:48:40 +0000 | [diff] [blame] | 25 | #ifdef CONFIG_DMA_NONCOHERENT |
Ralf Baechle | e5adb87 | 2005-10-20 22:55:26 +0100 | [diff] [blame] | 26 | #undef CONFIG_CPU_HAS_PREFETCH |
| 27 | #endif |
| 28 | #ifdef CONFIG_MIPS_MALTA |
| 29 | #undef CONFIG_CPU_HAS_PREFETCH |
| 30 | #endif |
| 31 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <asm/asm.h> |
Sam Ravnborg | 048eb58 | 2005-09-09 22:32:31 +0200 | [diff] [blame] | 33 | #include <asm/asm-offsets.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <asm/regdef.h> |
| 35 | |
| 36 | #define dst a0 |
| 37 | #define src a1 |
| 38 | #define len a2 |
| 39 | |
| 40 | /* |
| 41 | * Spec |
| 42 | * |
| 43 | * memcpy copies len bytes from src to dst and sets v0 to dst. |
| 44 | * It assumes that |
| 45 | * - src and dst don't overlap |
| 46 | * - src is readable |
| 47 | * - dst is writable |
| 48 | * memcpy uses the standard calling convention |
| 49 | * |
| 50 | * __copy_user copies up to len bytes from src to dst and sets a2 (len) to |
| 51 | * the number of uncopied bytes due to an exception caused by a read or write. |
| 52 | * __copy_user assumes that src and dst don't overlap, and that the call is |
| 53 | * implementing one of the following: |
| 54 | * copy_to_user |
| 55 | * - src is readable (no exceptions when reading src) |
| 56 | * copy_from_user |
| 57 | * - dst is writable (no exceptions when writing dst) |
| 58 | * __copy_user uses a non-standard calling convention; see |
| 59 | * include/asm-mips/uaccess.h |
| 60 | * |
| 61 | * When an exception happens on a load, the handler must |
| 62 | # ensure that all of the destination buffer is overwritten to prevent |
| 63 | * leaking information to user mode programs. |
| 64 | */ |
| 65 | |
| 66 | /* |
| 67 | * Implementation |
| 68 | */ |
| 69 | |
| 70 | /* |
| 71 | * The exception handler for loads requires that: |
| 72 | * 1- AT contain the address of the byte just past the end of the source |
| 73 | * of the copy, |
| 74 | * 2- src_entry <= src < AT, and |
| 75 | * 3- (dst - src) == (dst_entry - src_entry), |
| 76 | * The _entry suffix denotes values when __copy_user was called. |
| 77 | * |
| 78 | * (1) is set up up by uaccess.h and maintained by not writing AT in copy_user |
| 79 | * (2) is met by incrementing src by the number of bytes copied |
| 80 | * (3) is met by not doing loads between a pair of increments of dst and src |
| 81 | * |
| 82 | * The exception handlers for stores adjust len (if necessary) and return. |
| 83 | * These handlers do not need to overwrite any data. |
| 84 | * |
| 85 | * For __rmemcpy and memmove an exception is always a kernel bug, therefore |
| 86 | * they're not protected. |
| 87 | */ |
| 88 | |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 89 | /* Instruction type */ |
| 90 | #define LD_INSN 1 |
| 91 | #define ST_INSN 2 |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 92 | /* Pretech type */ |
| 93 | #define SRC_PREFETCH 1 |
| 94 | #define DST_PREFETCH 2 |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 95 | #define LEGACY_MODE 1 |
| 96 | #define EVA_MODE 2 |
| 97 | #define USEROP 1 |
| 98 | #define KERNELOP 2 |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 99 | |
| 100 | /* |
| 101 | * Wrapper to add an entry in the exception table |
| 102 | * in case the insn causes a memory exception. |
| 103 | * Arguments: |
| 104 | * insn : Load/store instruction |
| 105 | * type : Instruction type |
| 106 | * reg : Register |
| 107 | * addr : Address |
| 108 | * handler : Exception handler |
| 109 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 111 | #define EXC(insn, type, reg, addr, handler) \ |
| 112 | .if \mode == LEGACY_MODE; \ |
| 113 | 9: insn reg, addr; \ |
| 114 | .section __ex_table,"a"; \ |
| 115 | PTR 9b, handler; \ |
| 116 | .previous; \ |
| 117 | .endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | /* |
| 119 | * Only on the 64-bit kernel we can made use of 64-bit registers. |
| 120 | */ |
Ralf Baechle | 875d43e | 2005-09-03 15:56:16 -0700 | [diff] [blame] | 121 | #ifdef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | #define USE_DOUBLE |
| 123 | #endif |
| 124 | |
| 125 | #ifdef USE_DOUBLE |
| 126 | |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 127 | #define LOADK ld /* No exception */ |
| 128 | #define LOAD(reg, addr, handler) EXC(ld, LD_INSN, reg, addr, handler) |
| 129 | #define LOADL(reg, addr, handler) EXC(ldl, LD_INSN, reg, addr, handler) |
| 130 | #define LOADR(reg, addr, handler) EXC(ldr, LD_INSN, reg, addr, handler) |
| 131 | #define STOREL(reg, addr, handler) EXC(sdl, ST_INSN, reg, addr, handler) |
| 132 | #define STORER(reg, addr, handler) EXC(sdr, ST_INSN, reg, addr, handler) |
| 133 | #define STORE(reg, addr, handler) EXC(sd, ST_INSN, reg, addr, handler) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | #define ADD daddu |
| 135 | #define SUB dsubu |
| 136 | #define SRL dsrl |
| 137 | #define SRA dsra |
| 138 | #define SLL dsll |
| 139 | #define SLLV dsllv |
| 140 | #define SRLV dsrlv |
| 141 | #define NBYTES 8 |
| 142 | #define LOG_NBYTES 3 |
| 143 | |
Ralf Baechle | 42a3b4f | 2005-09-03 15:56:17 -0700 | [diff] [blame] | 144 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | * As we are sharing code base with the mips32 tree (which use the o32 ABI |
| 146 | * register definitions). We need to redefine the register definitions from |
| 147 | * the n64 ABI register naming to the o32 ABI register naming. |
| 148 | */ |
| 149 | #undef t0 |
| 150 | #undef t1 |
| 151 | #undef t2 |
| 152 | #undef t3 |
| 153 | #define t0 $8 |
| 154 | #define t1 $9 |
| 155 | #define t2 $10 |
| 156 | #define t3 $11 |
| 157 | #define t4 $12 |
| 158 | #define t5 $13 |
| 159 | #define t6 $14 |
| 160 | #define t7 $15 |
Ralf Baechle | 42a3b4f | 2005-09-03 15:56:17 -0700 | [diff] [blame] | 161 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | #else |
| 163 | |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 164 | #define LOADK lw /* No exception */ |
| 165 | #define LOAD(reg, addr, handler) EXC(lw, LD_INSN, reg, addr, handler) |
| 166 | #define LOADL(reg, addr, handler) EXC(lwl, LD_INSN, reg, addr, handler) |
| 167 | #define LOADR(reg, addr, handler) EXC(lwr, LD_INSN, reg, addr, handler) |
| 168 | #define STOREL(reg, addr, handler) EXC(swl, ST_INSN, reg, addr, handler) |
| 169 | #define STORER(reg, addr, handler) EXC(swr, ST_INSN, reg, addr, handler) |
| 170 | #define STORE(reg, addr, handler) EXC(sw, ST_INSN, reg, addr, handler) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | #define ADD addu |
| 172 | #define SUB subu |
| 173 | #define SRL srl |
| 174 | #define SLL sll |
| 175 | #define SRA sra |
| 176 | #define SLLV sllv |
| 177 | #define SRLV srlv |
| 178 | #define NBYTES 4 |
| 179 | #define LOG_NBYTES 2 |
| 180 | |
| 181 | #endif /* USE_DOUBLE */ |
| 182 | |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 183 | #define LOADB(reg, addr, handler) EXC(lb, LD_INSN, reg, addr, handler) |
| 184 | #define STOREB(reg, addr, handler) EXC(sb, ST_INSN, reg, addr, handler) |
| 185 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 186 | #define _PREF(hint, addr, type) \ |
| 187 | .if \mode == LEGACY_MODE; \ |
| 188 | PREF(hint, addr); \ |
| 189 | .endif |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 190 | |
| 191 | #define PREFS(hint, addr) _PREF(hint, addr, SRC_PREFETCH) |
| 192 | #define PREFD(hint, addr) _PREF(hint, addr, DST_PREFETCH) |
| 193 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | #ifdef CONFIG_CPU_LITTLE_ENDIAN |
| 195 | #define LDFIRST LOADR |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 196 | #define LDREST LOADL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | #define STFIRST STORER |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 198 | #define STREST STOREL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | #define SHIFT_DISCARD SLLV |
| 200 | #else |
| 201 | #define LDFIRST LOADL |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 202 | #define LDREST LOADR |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | #define STFIRST STOREL |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 204 | #define STREST STORER |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | #define SHIFT_DISCARD SRLV |
| 206 | #endif |
| 207 | |
| 208 | #define FIRST(unit) ((unit)*NBYTES) |
| 209 | #define REST(unit) (FIRST(unit)+NBYTES-1) |
| 210 | #define UNIT(unit) FIRST(unit) |
| 211 | |
| 212 | #define ADDRMASK (NBYTES-1) |
| 213 | |
| 214 | .text |
| 215 | .set noreorder |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 216 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | .set noat |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 218 | #else |
| 219 | .set at=v1 |
| 220 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 221 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | .align 5 |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 223 | |
| 224 | /* |
| 225 | * Macro to build the __copy_user common code |
| 226 | * Arguements: |
| 227 | * mode : LEGACY_MODE or EVA_MODE |
| 228 | * from : Source operand. USEROP or KERNELOP |
| 229 | * to : Destination operand. USEROP or KERNELOP |
| 230 | */ |
| 231 | .macro __BUILD_COPY_USER mode, from, to |
| 232 | |
| 233 | /* initialize __memcpy if this the first time we execute this macro */ |
| 234 | .ifnotdef __memcpy |
| 235 | .set __memcpy, 1 |
| 236 | .hidden __memcpy /* make sure it does not leak */ |
| 237 | .endif |
| 238 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | /* |
| 240 | * Note: dst & src may be unaligned, len may be 0 |
| 241 | * Temps |
| 242 | */ |
| 243 | #define rem t8 |
| 244 | |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 245 | R10KCBARRIER(0(ra)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | /* |
| 247 | * The "issue break"s below are very approximate. |
| 248 | * Issue delays for dcache fills will perturb the schedule, as will |
| 249 | * load queue full replay traps, etc. |
| 250 | * |
| 251 | * If len < NBYTES use byte operations. |
| 252 | */ |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 253 | PREFS( 0, 0(src) ) |
| 254 | PREFD( 1, 0(dst) ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | sltu t2, len, NBYTES |
| 256 | and t1, dst, ADDRMASK |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 257 | PREFS( 0, 1*32(src) ) |
| 258 | PREFD( 1, 1*32(dst) ) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 259 | bnez t2, .Lcopy_bytes_checklen\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | and t0, src, ADDRMASK |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 261 | PREFS( 0, 2*32(src) ) |
| 262 | PREFD( 1, 2*32(dst) ) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 263 | bnez t1, .Ldst_unaligned\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | nop |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 265 | bnez t0, .Lsrc_unaligned_dst_aligned\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | /* |
| 267 | * use delay slot for fall-through |
| 268 | * src and dst are aligned; need to compute rem |
| 269 | */ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 270 | .Lboth_aligned\@: |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 271 | SRL t0, len, LOG_NBYTES+3 # +3 for 8 units/iter |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 272 | beqz t0, .Lcleanup_both_aligned\@ # len < 8*NBYTES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | and rem, len, (8*NBYTES-1) # rem = len % (8*NBYTES) |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 274 | PREFS( 0, 3*32(src) ) |
| 275 | PREFD( 1, 3*32(dst) ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | .align 4 |
| 277 | 1: |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 278 | R10KCBARRIER(0(ra)) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 279 | LOAD(t0, UNIT(0)(src), .Ll_exc\@) |
| 280 | LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@) |
| 281 | LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@) |
| 282 | LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | SUB len, len, 8*NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 284 | LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@) |
| 285 | LOAD(t7, UNIT(5)(src), .Ll_exc_copy\@) |
| 286 | STORE(t0, UNIT(0)(dst), .Ls_exc_p8u\@) |
| 287 | STORE(t1, UNIT(1)(dst), .Ls_exc_p7u\@) |
| 288 | LOAD(t0, UNIT(6)(src), .Ll_exc_copy\@) |
| 289 | LOAD(t1, UNIT(7)(src), .Ll_exc_copy\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | ADD src, src, 8*NBYTES |
| 291 | ADD dst, dst, 8*NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 292 | STORE(t2, UNIT(-6)(dst), .Ls_exc_p6u\@) |
| 293 | STORE(t3, UNIT(-5)(dst), .Ls_exc_p5u\@) |
| 294 | STORE(t4, UNIT(-4)(dst), .Ls_exc_p4u\@) |
| 295 | STORE(t7, UNIT(-3)(dst), .Ls_exc_p3u\@) |
| 296 | STORE(t0, UNIT(-2)(dst), .Ls_exc_p2u\@) |
| 297 | STORE(t1, UNIT(-1)(dst), .Ls_exc_p1u\@) |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 298 | PREFS( 0, 8*32(src) ) |
| 299 | PREFD( 1, 8*32(dst) ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | bne len, rem, 1b |
| 301 | nop |
| 302 | |
| 303 | /* |
| 304 | * len == rem == the number of bytes left to copy < 8*NBYTES |
| 305 | */ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 306 | .Lcleanup_both_aligned\@: |
| 307 | beqz len, .Ldone\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | sltu t0, len, 4*NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 309 | bnez t0, .Lless_than_4units\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | and rem, len, (NBYTES-1) # rem = len % NBYTES |
| 311 | /* |
| 312 | * len >= 4*NBYTES |
| 313 | */ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 314 | LOAD( t0, UNIT(0)(src), .Ll_exc\@) |
| 315 | LOAD( t1, UNIT(1)(src), .Ll_exc_copy\@) |
| 316 | LOAD( t2, UNIT(2)(src), .Ll_exc_copy\@) |
| 317 | LOAD( t3, UNIT(3)(src), .Ll_exc_copy\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | SUB len, len, 4*NBYTES |
| 319 | ADD src, src, 4*NBYTES |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 320 | R10KCBARRIER(0(ra)) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 321 | STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@) |
| 322 | STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@) |
| 323 | STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@) |
| 324 | STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@) |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 325 | .set reorder /* DADDI_WAR */ |
| 326 | ADD dst, dst, 4*NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 327 | beqz len, .Ldone\@ |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 328 | .set noreorder |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 329 | .Lless_than_4units\@: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | /* |
| 331 | * rem = len % NBYTES |
| 332 | */ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 333 | beq rem, len, .Lcopy_bytes\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | nop |
| 335 | 1: |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 336 | R10KCBARRIER(0(ra)) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 337 | LOAD(t0, 0(src), .Ll_exc\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | ADD src, src, NBYTES |
| 339 | SUB len, len, NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 340 | STORE(t0, 0(dst), .Ls_exc_p1u\@) |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 341 | .set reorder /* DADDI_WAR */ |
| 342 | ADD dst, dst, NBYTES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | bne rem, len, 1b |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 344 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | |
| 346 | /* |
| 347 | * src and dst are aligned, need to copy rem bytes (rem < NBYTES) |
| 348 | * A loop would do only a byte at a time with possible branch |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 349 | * mispredicts. Can't do an explicit LOAD dst,mask,or,STORE |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | * because can't assume read-access to dst. Instead, use |
| 351 | * STREST dst, which doesn't require read access to dst. |
| 352 | * |
| 353 | * This code should perform better than a simple loop on modern, |
| 354 | * wide-issue mips processors because the code has fewer branches and |
| 355 | * more instruction-level parallelism. |
| 356 | */ |
| 357 | #define bits t2 |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 358 | beqz len, .Ldone\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | ADD t1, dst, len # t1 is just past last byte of dst |
| 360 | li bits, 8*NBYTES |
| 361 | SLL rem, len, 3 # rem = number of bits to keep |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 362 | LOAD(t0, 0(src), .Ll_exc\@) |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 363 | SUB bits, bits, rem # bits = number of bits to discard |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | SHIFT_DISCARD t0, t0, bits |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 365 | STREST(t0, -1(t1), .Ls_exc\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | jr ra |
| 367 | move len, zero |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 368 | .Ldst_unaligned\@: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | /* |
| 370 | * dst is unaligned |
| 371 | * t0 = src & ADDRMASK |
| 372 | * t1 = dst & ADDRMASK; T1 > 0 |
| 373 | * len >= NBYTES |
| 374 | * |
| 375 | * Copy enough bytes to align dst |
| 376 | * Set match = (src and dst have same alignment) |
| 377 | */ |
| 378 | #define match rem |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 379 | LDFIRST(t3, FIRST(0)(src), .Ll_exc\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | ADD t2, zero, NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 381 | LDREST(t3, REST(0)(src), .Ll_exc_copy\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | SUB t2, t2, t1 # t2 = number of bytes copied |
| 383 | xor match, t0, t1 |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 384 | R10KCBARRIER(0(ra)) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 385 | STFIRST(t3, FIRST(0)(dst), .Ls_exc\@) |
| 386 | beq len, t2, .Ldone\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | SUB len, len, t2 |
| 388 | ADD dst, dst, t2 |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 389 | beqz match, .Lboth_aligned\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | ADD src, src, t2 |
| 391 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 392 | .Lsrc_unaligned_dst_aligned\@: |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 393 | SRL t0, len, LOG_NBYTES+2 # +2 for 4 units/iter |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 394 | PREFS( 0, 3*32(src) ) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 395 | beqz t0, .Lcleanup_src_unaligned\@ |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 396 | and rem, len, (4*NBYTES-1) # rem = len % 4*NBYTES |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 397 | PREFD( 1, 3*32(dst) ) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | 1: |
| 399 | /* |
| 400 | * Avoid consecutive LD*'s to the same register since some mips |
| 401 | * implementations can't issue them in the same cycle. |
| 402 | * It's OK to load FIRST(N+1) before REST(N) because the two addresses |
| 403 | * are to the same unit (unless src is aligned, but it's not). |
| 404 | */ |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 405 | R10KCBARRIER(0(ra)) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 406 | LDFIRST(t0, FIRST(0)(src), .Ll_exc\@) |
| 407 | LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@) |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 408 | SUB len, len, 4*NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 409 | LDREST(t0, REST(0)(src), .Ll_exc_copy\@) |
| 410 | LDREST(t1, REST(1)(src), .Ll_exc_copy\@) |
| 411 | LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@) |
| 412 | LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@) |
| 413 | LDREST(t2, REST(2)(src), .Ll_exc_copy\@) |
| 414 | LDREST(t3, REST(3)(src), .Ll_exc_copy\@) |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 415 | PREFS( 0, 9*32(src) ) # 0 is PREF_LOAD (not streamed) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | ADD src, src, 4*NBYTES |
| 417 | #ifdef CONFIG_CPU_SB1 |
| 418 | nop # improves slotting |
| 419 | #endif |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 420 | STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@) |
| 421 | STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@) |
| 422 | STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@) |
| 423 | STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@) |
Markos Chandras | bda4d98 | 2014-01-07 15:59:03 +0000 | [diff] [blame] | 424 | PREFD( 1, 9*32(dst) ) # 1 is PREF_STORE (not streamed) |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 425 | .set reorder /* DADDI_WAR */ |
| 426 | ADD dst, dst, 4*NBYTES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | bne len, rem, 1b |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 428 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 430 | .Lcleanup_src_unaligned\@: |
| 431 | beqz len, .Ldone\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | and rem, len, NBYTES-1 # rem = len % NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 433 | beq rem, len, .Lcopy_bytes\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | nop |
| 435 | 1: |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 436 | R10KCBARRIER(0(ra)) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 437 | LDFIRST(t0, FIRST(0)(src), .Ll_exc\@) |
| 438 | LDREST(t0, REST(0)(src), .Ll_exc_copy\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | ADD src, src, NBYTES |
| 440 | SUB len, len, NBYTES |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 441 | STORE(t0, 0(dst), .Ls_exc_p1u\@) |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 442 | .set reorder /* DADDI_WAR */ |
| 443 | ADD dst, dst, NBYTES |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | bne len, rem, 1b |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 445 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 447 | .Lcopy_bytes_checklen\@: |
| 448 | beqz len, .Ldone\@ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | nop |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 450 | .Lcopy_bytes\@: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | /* 0 < len < NBYTES */ |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 452 | R10KCBARRIER(0(ra)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | #define COPY_BYTE(N) \ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 454 | LOADB(t0, N(src), .Ll_exc\@); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | SUB len, len, 1; \ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 456 | beqz len, .Ldone\@; \ |
| 457 | STOREB(t0, N(dst), .Ls_exc_p1\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | |
| 459 | COPY_BYTE(0) |
| 460 | COPY_BYTE(1) |
| 461 | #ifdef USE_DOUBLE |
| 462 | COPY_BYTE(2) |
| 463 | COPY_BYTE(3) |
| 464 | COPY_BYTE(4) |
| 465 | COPY_BYTE(5) |
| 466 | #endif |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 467 | LOADB(t0, NBYTES-2(src), .Ll_exc\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | SUB len, len, 1 |
| 469 | jr ra |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 470 | STOREB(t0, NBYTES-2(dst), .Ls_exc_p1\@) |
| 471 | .Ldone\@: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | jr ra |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 473 | .if __memcpy == 1 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 474 | END(memcpy) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 475 | .set __memcpy, 0 |
| 476 | .hidden __memcpy |
| 477 | .endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 479 | .Ll_exc_copy\@: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | /* |
| 481 | * Copy bytes from src until faulting load address (or until a |
| 482 | * lb faults) |
| 483 | * |
| 484 | * When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28) |
| 485 | * may be more than a byte beyond the last address. |
| 486 | * Hence, the lb below may get an exception. |
| 487 | * |
| 488 | * Assumes src < THREAD_BUADDR($28) |
| 489 | */ |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 490 | LOADK t0, TI_TASK($28) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | nop |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 492 | LOADK t0, THREAD_BUADDR(t0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | 1: |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 494 | LOADB(t1, 0(src), .Ll_exc\@) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | ADD src, src, 1 |
| 496 | sb t1, 0(dst) # can't fault -- we're copy_from_user |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 497 | .set reorder /* DADDI_WAR */ |
| 498 | ADD dst, dst, 1 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | bne src, t0, 1b |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 500 | .set noreorder |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 501 | .Ll_exc\@: |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 502 | LOADK t0, TI_TASK($28) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | nop |
Markos Chandras | 5bc0597 | 2014-01-07 12:57:04 +0000 | [diff] [blame] | 504 | LOADK t0, THREAD_BUADDR(t0) # t0 is just past last good address |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | nop |
| 506 | SUB len, AT, t0 # len number of uncopied bytes |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 507 | bnez t6, .Ldone\@ /* Skip the zeroing part if inatomic */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | /* |
| 509 | * Here's where we rely on src and dst being incremented in tandem, |
| 510 | * See (3) above. |
| 511 | * dst += (fault addr - src) to put dst at first byte to clear |
| 512 | */ |
| 513 | ADD dst, t0 # compute start address in a1 |
| 514 | SUB dst, src |
| 515 | /* |
| 516 | * Clear len bytes starting at dst. Can't call __bzero because it |
| 517 | * might modify len. An inefficient loop for these rare times... |
| 518 | */ |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 519 | .set reorder /* DADDI_WAR */ |
| 520 | SUB src, len, 1 |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 521 | beqz len, .Ldone\@ |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 522 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | 1: sb zero, 0(dst) |
| 524 | ADD dst, dst, 1 |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 525 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | bnez src, 1b |
| 527 | SUB src, src, 1 |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 528 | #else |
| 529 | .set push |
| 530 | .set noat |
| 531 | li v1, 1 |
| 532 | bnez src, 1b |
| 533 | SUB src, src, v1 |
| 534 | .set pop |
| 535 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | jr ra |
| 537 | nop |
| 538 | |
| 539 | |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 540 | #define SEXC(n) \ |
Ralf Baechle | 7034228 | 2013-01-22 12:59:30 +0100 | [diff] [blame] | 541 | .set reorder; /* DADDI_WAR */ \ |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 542 | .Ls_exc_p ## n ## u\@: \ |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 543 | ADD len, len, n*NBYTES; \ |
| 544 | jr ra; \ |
| 545 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | |
| 547 | SEXC(8) |
| 548 | SEXC(7) |
| 549 | SEXC(6) |
| 550 | SEXC(5) |
| 551 | SEXC(4) |
| 552 | SEXC(3) |
| 553 | SEXC(2) |
| 554 | SEXC(1) |
| 555 | |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 556 | .Ls_exc_p1\@: |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 557 | .set reorder /* DADDI_WAR */ |
| 558 | ADD len, len, 1 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | jr ra |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 560 | .set noreorder |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 561 | .Ls_exc\@: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | jr ra |
| 563 | nop |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 564 | .endm |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | |
| 566 | .align 5 |
| 567 | LEAF(memmove) |
| 568 | ADD t0, a0, a2 |
| 569 | ADD t1, a1, a2 |
| 570 | sltu t0, a1, t0 # dst + len <= src -> memcpy |
| 571 | sltu t1, a0, t1 # dst >= src + len -> memcpy |
| 572 | and t0, t1 |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 573 | beqz t0, .L__memcpy |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | move v0, a0 /* return value */ |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 575 | beqz a2, .Lr_out |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | END(memmove) |
| 577 | |
| 578 | /* fall through to __rmemcpy */ |
| 579 | LEAF(__rmemcpy) /* a0=dst a1=src a2=len */ |
| 580 | sltu t0, a1, a0 |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 581 | beqz t0, .Lr_end_bytes_up # src >= dst |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | nop |
| 583 | ADD a0, a2 # dst = dst + len |
| 584 | ADD a1, a2 # src = src + len |
| 585 | |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 586 | .Lr_end_bytes: |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 587 | R10KCBARRIER(0(ra)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | lb t0, -1(a1) |
| 589 | SUB a2, a2, 0x1 |
| 590 | sb t0, -1(a0) |
| 591 | SUB a1, a1, 0x1 |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 592 | .set reorder /* DADDI_WAR */ |
| 593 | SUB a0, a0, 0x1 |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 594 | bnez a2, .Lr_end_bytes |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 595 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 597 | .Lr_out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | jr ra |
| 599 | move a2, zero |
| 600 | |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 601 | .Lr_end_bytes_up: |
Thomas Bogendoerfer | 930bff8 | 2007-11-25 11:47:56 +0100 | [diff] [blame] | 602 | R10KCBARRIER(0(ra)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | lb t0, (a1) |
| 604 | SUB a2, a2, 0x1 |
| 605 | sb t0, (a0) |
| 606 | ADD a1, a1, 0x1 |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 607 | .set reorder /* DADDI_WAR */ |
| 608 | ADD a0, a0, 0x1 |
Ralf Baechle | c5ec198 | 2008-01-29 10:14:59 +0000 | [diff] [blame] | 609 | bnez a2, .Lr_end_bytes_up |
Maciej W. Rozycki | 619b6e1 | 2007-10-23 12:43:25 +0100 | [diff] [blame] | 610 | .set noreorder |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | |
| 612 | jr ra |
| 613 | move a2, zero |
| 614 | END(__rmemcpy) |
Markos Chandras | cf62a8b | 2014-01-07 14:34:05 +0000 | [diff] [blame^] | 615 | |
| 616 | /* |
| 617 | * t6 is used as a flag to note inatomic mode. |
| 618 | */ |
| 619 | LEAF(__copy_user_inatomic) |
| 620 | b __copy_user_common |
| 621 | li t6, 1 |
| 622 | END(__copy_user_inatomic) |
| 623 | |
| 624 | /* |
| 625 | * A combined memcpy/__copy_user |
| 626 | * __copy_user sets len to 0 for success; else to an upper bound of |
| 627 | * the number of uncopied bytes. |
| 628 | * memcpy sets v0 to dst. |
| 629 | */ |
| 630 | .align 5 |
| 631 | LEAF(memcpy) /* a0=dst a1=src a2=len */ |
| 632 | move v0, dst /* return value */ |
| 633 | .L__memcpy: |
| 634 | FEXPORT(__copy_user) |
| 635 | li t6, 0 /* not inatomic */ |
| 636 | __copy_user_common: |
| 637 | /* Legacy Mode, user <-> user */ |
| 638 | __BUILD_COPY_USER LEGACY_MODE USEROP USEROP |