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 | * Copyright (C) 1994, 1995, 1996, 1998, 1999, 2002, 2003 Ralf Baechle |
Justin P. Mattock | 79add62 | 2011-04-04 14:15:29 -0700 | [diff] [blame] | 7 | * Copyright (C) 1996 David S. Miller (davem@davemloft.net) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * Copyright (C) 1994, 1995, 1996, by Andreas Busse |
| 9 | * Copyright (C) 1999 Silicon Graphics, Inc. |
| 10 | * Copyright (C) 2000 MIPS Technologies, Inc. |
| 11 | * written by Carsten Langgaard, carstenl@mips.com |
| 12 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <asm/asm.h> |
| 14 | #include <asm/cachectl.h> |
| 15 | #include <asm/fpregdef.h> |
| 16 | #include <asm/mipsregs.h> |
Sam Ravnborg | 048eb58 | 2005-09-09 22:32:31 +0200 | [diff] [blame] | 17 | #include <asm/asm-offsets.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <asm/pgtable-bits.h> |
| 19 | #include <asm/regdef.h> |
| 20 | #include <asm/stackframe.h> |
| 21 | #include <asm/thread_info.h> |
| 22 | |
| 23 | #include <asm/asmmacro.h> |
| 24 | |
| 25 | /* |
| 26 | * Offset to the current process status flags, the first 32 bytes of the |
| 27 | * stack are not used. |
| 28 | */ |
| 29 | #define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS) |
| 30 | |
David Daney | a36d822 | 2014-05-28 23:52:04 +0200 | [diff] [blame] | 31 | #ifndef USE_ALTERNATE_RESUME_IMPL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | * task_struct *resume(task_struct *prev, task_struct *next, |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 34 | * struct thread_info *next_ti, s32 fp_save) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | */ |
| 36 | .align 5 |
| 37 | LEAF(resume) |
Atsushi Nemoto | 5323180 | 2007-04-14 02:37:26 +0900 | [diff] [blame] | 38 | mfc0 t1, CP0_STATUS |
| 39 | LONG_S t1, THREAD_STATUS(a0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | cpu_save_nonscratch a0 |
| 41 | LONG_S ra, THREAD_REG31(a0) |
| 42 | |
| 43 | /* |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 44 | * Check whether we need to save any FP context. FP context is saved |
| 45 | * iff the process has used the context with the scalar FPU or the MSA |
| 46 | * ASE in the current time slice, as indicated by _TIF_USEDFPU and |
| 47 | * _TIF_USEDMSA respectively. switch_to will have set fp_save |
| 48 | * accordingly to an FP_SAVE_ enum value. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | */ |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 50 | beqz a3, 2f |
Leonid Yegoshin | 2dd1703 | 2012-07-19 09:11:14 +0200 | [diff] [blame] | 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | /* |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 53 | * We do. Clear the saved CU1 bit for prev, such that next time it is |
| 54 | * scheduled it will start in userland with the FPU disabled. If the |
| 55 | * task uses the FPU then it will be enabled again via the do_cpu trap. |
| 56 | * This allows us to lazily restore the FP context. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | */ |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 58 | PTR_L t3, TASK_THREAD_INFO(a0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | LONG_L t0, ST_OFF(t3) |
| 60 | li t1, ~ST0_CU1 |
| 61 | and t0, t0, t1 |
| 62 | LONG_S t0, ST_OFF(t3) |
| 63 | |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 64 | /* Check whether we're saving scalar or vector context. */ |
| 65 | bgtz a3, 1f |
| 66 | |
Paul Burton | b834067 | 2014-07-11 16:44:29 +0100 | [diff] [blame] | 67 | /* Save 128b MSA vector context + scalar FP control & status. */ |
| 68 | cfc1 t1, fcr31 |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 69 | msa_save_all a0 |
Paul Burton | b834067 | 2014-07-11 16:44:29 +0100 | [diff] [blame] | 70 | sw t1, THREAD_FCR31(a0) |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 71 | b 2f |
| 72 | |
| 73 | 1: /* Save 32b/64b scalar FP context. */ |
Atsushi Nemoto | c138e12 | 2006-05-23 00:47:41 +0900 | [diff] [blame] | 74 | fpu_save_double a0 t0 t1 # c0_status passed in t0 |
| 75 | # clobbers t1 |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 76 | 2: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
Gregory Fong | 1400eb6 | 2013-06-17 19:36:07 +0000 | [diff] [blame] | 78 | #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP) |
James Hogan | 8b3c569 | 2013-10-07 12:14:26 +0100 | [diff] [blame] | 79 | PTR_LA t8, __stack_chk_guard |
Gregory Fong | 1400eb6 | 2013-06-17 19:36:07 +0000 | [diff] [blame] | 80 | LONG_L t9, TASK_STACK_CANARY(a1) |
| 81 | LONG_S t9, 0(t8) |
| 82 | #endif |
| 83 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | /* |
| 85 | * The order of restoring the registers takes care of the race |
| 86 | * updating $28, $29 and kernelsp without disabling ints. |
| 87 | */ |
| 88 | move $28, a2 |
| 89 | cpu_restore_nonscratch a1 |
| 90 | |
Ralf Baechle | 3bd3966 | 2007-07-11 08:32:21 +0100 | [diff] [blame] | 91 | PTR_ADDU t0, $28, _THREAD_SIZE - 32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | set_saved_sp t0, t1, t2 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | mfc0 t1, CP0_STATUS /* Do we really need this? */ |
| 94 | li a3, 0xff01 |
| 95 | and t1, a3 |
| 96 | LONG_L a2, THREAD_STATUS(a1) |
| 97 | nor a3, $0, a3 |
| 98 | and a2, a3 |
| 99 | or a2, t1 |
| 100 | mtc0 a2, CP0_STATUS |
| 101 | move v0, a0 |
| 102 | jr ra |
| 103 | END(resume) |
| 104 | |
David Daney | a36d822 | 2014-05-28 23:52:04 +0200 | [diff] [blame] | 105 | #endif /* USE_ALTERNATE_RESUME_IMPL */ |
| 106 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | /* |
| 108 | * Save a thread's fp context. |
| 109 | */ |
| 110 | LEAF(_save_fp) |
Paul Burton | 597ce17 | 2013-11-22 13:12:07 +0000 | [diff] [blame] | 111 | #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2) |
Atsushi Nemoto | c138e12 | 2006-05-23 00:47:41 +0900 | [diff] [blame] | 112 | mfc0 t0, CP0_STATUS |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | #endif |
Atsushi Nemoto | c138e12 | 2006-05-23 00:47:41 +0900 | [diff] [blame] | 114 | fpu_save_double a0 t0 t1 # clobbers t1 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | jr ra |
| 116 | END(_save_fp) |
| 117 | |
| 118 | /* |
| 119 | * Restore a thread's fp context. |
| 120 | */ |
| 121 | LEAF(_restore_fp) |
Paul Burton | 597ce17 | 2013-11-22 13:12:07 +0000 | [diff] [blame] | 122 | #if defined(CONFIG_64BIT) || defined(CONFIG_CPU_MIPS32_R2) |
Atsushi Nemoto | c138e12 | 2006-05-23 00:47:41 +0900 | [diff] [blame] | 123 | mfc0 t0, CP0_STATUS |
| 124 | #endif |
| 125 | fpu_restore_double a0 t0 t1 # clobbers t1 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | jr ra |
| 127 | END(_restore_fp) |
| 128 | |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 129 | #ifdef CONFIG_CPU_HAS_MSA |
| 130 | |
| 131 | /* |
| 132 | * Save a thread's MSA vector context. |
| 133 | */ |
| 134 | LEAF(_save_msa) |
| 135 | msa_save_all a0 |
| 136 | jr ra |
| 137 | END(_save_msa) |
| 138 | |
| 139 | /* |
| 140 | * Restore a thread's MSA vector context. |
| 141 | */ |
| 142 | LEAF(_restore_msa) |
| 143 | msa_restore_all a0 |
| 144 | jr ra |
| 145 | END(_restore_msa) |
| 146 | |
Paul Burton | c901775 | 2014-07-30 08:53:20 +0100 | [diff] [blame^] | 147 | LEAF(_init_msa_upper) |
| 148 | msa_init_all_upper |
| 149 | jr ra |
| 150 | END(_init_msa_upper) |
| 151 | |
Paul Burton | 1db1af8 | 2014-01-27 15:23:11 +0000 | [diff] [blame] | 152 | #endif |
| 153 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | /* |
| 155 | * Load the FPU with signalling NANS. This bit pattern we're using has |
| 156 | * the property that no matter whether considered as single or as double |
| 157 | * precision represents signaling NANS. |
| 158 | * |
| 159 | * We initialize fcr31 to rounding to nearest, no exceptions. |
| 160 | */ |
| 161 | |
| 162 | #define FPU_DEFAULT 0x00000000 |
| 163 | |
| 164 | LEAF(_init_fpu) |
| 165 | mfc0 t0, CP0_STATUS |
| 166 | li t1, ST0_CU1 |
| 167 | or t0, t1 |
| 168 | mtc0 t0, CP0_STATUS |
Chris Dearman | f9509c8 | 2007-05-17 21:36:55 +0100 | [diff] [blame] | 169 | enable_fpu_hazard |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | |
| 171 | li t1, FPU_DEFAULT |
| 172 | ctc1 t1, fcr31 |
| 173 | |
| 174 | li t1, -1 # SNaN |
| 175 | |
Ralf Baechle | 875d43e | 2005-09-03 15:56:16 -0700 | [diff] [blame] | 176 | #ifdef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | sll t0, t0, 5 |
| 178 | bgez t0, 1f # 16 / 32 register mode? |
| 179 | |
| 180 | dmtc1 t1, $f1 |
| 181 | dmtc1 t1, $f3 |
| 182 | dmtc1 t1, $f5 |
| 183 | dmtc1 t1, $f7 |
| 184 | dmtc1 t1, $f9 |
| 185 | dmtc1 t1, $f11 |
| 186 | dmtc1 t1, $f13 |
| 187 | dmtc1 t1, $f15 |
| 188 | dmtc1 t1, $f17 |
| 189 | dmtc1 t1, $f19 |
| 190 | dmtc1 t1, $f21 |
| 191 | dmtc1 t1, $f23 |
| 192 | dmtc1 t1, $f25 |
| 193 | dmtc1 t1, $f27 |
| 194 | dmtc1 t1, $f29 |
| 195 | dmtc1 t1, $f31 |
| 196 | 1: |
| 197 | #endif |
Ralf Baechle | 42a3b4f | 2005-09-03 15:56:17 -0700 | [diff] [blame] | 198 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | #ifdef CONFIG_CPU_MIPS32 |
| 200 | mtc1 t1, $f0 |
| 201 | mtc1 t1, $f1 |
| 202 | mtc1 t1, $f2 |
| 203 | mtc1 t1, $f3 |
| 204 | mtc1 t1, $f4 |
| 205 | mtc1 t1, $f5 |
| 206 | mtc1 t1, $f6 |
| 207 | mtc1 t1, $f7 |
| 208 | mtc1 t1, $f8 |
| 209 | mtc1 t1, $f9 |
| 210 | mtc1 t1, $f10 |
| 211 | mtc1 t1, $f11 |
| 212 | mtc1 t1, $f12 |
| 213 | mtc1 t1, $f13 |
| 214 | mtc1 t1, $f14 |
| 215 | mtc1 t1, $f15 |
| 216 | mtc1 t1, $f16 |
| 217 | mtc1 t1, $f17 |
| 218 | mtc1 t1, $f18 |
| 219 | mtc1 t1, $f19 |
| 220 | mtc1 t1, $f20 |
| 221 | mtc1 t1, $f21 |
| 222 | mtc1 t1, $f22 |
| 223 | mtc1 t1, $f23 |
| 224 | mtc1 t1, $f24 |
| 225 | mtc1 t1, $f25 |
| 226 | mtc1 t1, $f26 |
| 227 | mtc1 t1, $f27 |
| 228 | mtc1 t1, $f28 |
| 229 | mtc1 t1, $f29 |
| 230 | mtc1 t1, $f30 |
| 231 | mtc1 t1, $f31 |
Paul Burton | 597ce17 | 2013-11-22 13:12:07 +0000 | [diff] [blame] | 232 | |
| 233 | #ifdef CONFIG_CPU_MIPS32_R2 |
| 234 | .set push |
| 235 | .set mips64r2 |
| 236 | sll t0, t0, 5 # is Status.FR set? |
| 237 | bgez t0, 1f # no: skip setting upper 32b |
| 238 | |
| 239 | mthc1 t1, $f0 |
| 240 | mthc1 t1, $f1 |
| 241 | mthc1 t1, $f2 |
| 242 | mthc1 t1, $f3 |
| 243 | mthc1 t1, $f4 |
| 244 | mthc1 t1, $f5 |
| 245 | mthc1 t1, $f6 |
| 246 | mthc1 t1, $f7 |
| 247 | mthc1 t1, $f8 |
| 248 | mthc1 t1, $f9 |
| 249 | mthc1 t1, $f10 |
| 250 | mthc1 t1, $f11 |
| 251 | mthc1 t1, $f12 |
| 252 | mthc1 t1, $f13 |
| 253 | mthc1 t1, $f14 |
| 254 | mthc1 t1, $f15 |
| 255 | mthc1 t1, $f16 |
| 256 | mthc1 t1, $f17 |
| 257 | mthc1 t1, $f18 |
| 258 | mthc1 t1, $f19 |
| 259 | mthc1 t1, $f20 |
| 260 | mthc1 t1, $f21 |
| 261 | mthc1 t1, $f22 |
| 262 | mthc1 t1, $f23 |
| 263 | mthc1 t1, $f24 |
| 264 | mthc1 t1, $f25 |
| 265 | mthc1 t1, $f26 |
| 266 | mthc1 t1, $f27 |
| 267 | mthc1 t1, $f28 |
| 268 | mthc1 t1, $f29 |
| 269 | mthc1 t1, $f30 |
| 270 | mthc1 t1, $f31 |
| 271 | 1: .set pop |
| 272 | #endif /* CONFIG_CPU_MIPS32_R2 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | #else |
Ralf Baechle | a809d46 | 2014-03-30 13:20:10 +0200 | [diff] [blame] | 274 | .set arch=r4000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | dmtc1 t1, $f0 |
| 276 | dmtc1 t1, $f2 |
| 277 | dmtc1 t1, $f4 |
| 278 | dmtc1 t1, $f6 |
| 279 | dmtc1 t1, $f8 |
| 280 | dmtc1 t1, $f10 |
| 281 | dmtc1 t1, $f12 |
| 282 | dmtc1 t1, $f14 |
| 283 | dmtc1 t1, $f16 |
| 284 | dmtc1 t1, $f18 |
| 285 | dmtc1 t1, $f20 |
| 286 | dmtc1 t1, $f22 |
| 287 | dmtc1 t1, $f24 |
| 288 | dmtc1 t1, $f26 |
| 289 | dmtc1 t1, $f28 |
| 290 | dmtc1 t1, $f30 |
| 291 | #endif |
| 292 | jr ra |
| 293 | END(_init_fpu) |