1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Transactional memory support routines to reclaim and recheckpoint 4 * transactional process state. 5 * 6 * Copyright 2012 Matt Evans & Michael Neuling, IBM Corporation. 7 */ 8 9#include <asm/asm-offsets.h> 10#include <asm/ppc_asm.h> 11#include <asm/ppc-opcode.h> 12#include <asm/ptrace.h> 13#include <asm/reg.h> 14#include <asm/bug.h> 15#include <asm/export.h> 16#include <asm/feature-fixups.h> 17 18#ifdef CONFIG_VSX 19/* See fpu.S, this is borrowed from there */ 20#define __SAVE_32FPRS_VSRS(n,c,base) \ 21BEGIN_FTR_SECTION \ 22 b 2f; \ 23END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ 24 SAVE_32FPRS(n,base); \ 25 b 3f; \ 262: SAVE_32VSRS(n,c,base); \ 273: 28#define __REST_32FPRS_VSRS(n,c,base) \ 29BEGIN_FTR_SECTION \ 30 b 2f; \ 31END_FTR_SECTION_IFSET(CPU_FTR_VSX); \ 32 REST_32FPRS(n,base); \ 33 b 3f; \ 342: REST_32VSRS(n,c,base); \ 353: 36#else 37#define __SAVE_32FPRS_VSRS(n,c,base) SAVE_32FPRS(n, base) 38#define __REST_32FPRS_VSRS(n,c,base) REST_32FPRS(n, base) 39#endif 40#define SAVE_32FPRS_VSRS(n,c,base) \ 41 __SAVE_32FPRS_VSRS(n,__REG_##c,__REG_##base) 42#define REST_32FPRS_VSRS(n,c,base) \ 43 __REST_32FPRS_VSRS(n,__REG_##c,__REG_##base) 44 45/* Stack frame offsets for local variables. */ 46#define TM_FRAME_L0 TM_FRAME_SIZE-16 47#define TM_FRAME_L1 TM_FRAME_SIZE-8 48 49 50/* In order to access the TM SPRs, TM must be enabled. So, do so: */ 51_GLOBAL(tm_enable) 52 mfmsr r4 53 li r3, MSR_TM >> 32 54 sldi r3, r3, 32 55 and. r0, r4, r3 56 bne 1f 57 or r4, r4, r3 58 mtmsrd r4 591: blr 60EXPORT_SYMBOL_GPL(tm_enable); 61 62_GLOBAL(tm_disable) 63 mfmsr r4 64 li r3, MSR_TM >> 32 65 sldi r3, r3, 32 66 andc r4, r4, r3 67 mtmsrd r4 68 blr 69EXPORT_SYMBOL_GPL(tm_disable); 70 71_GLOBAL(tm_save_sprs) 72 mfspr r0, SPRN_TFHAR 73 std r0, THREAD_TM_TFHAR(r3) 74 mfspr r0, SPRN_TEXASR 75 std r0, THREAD_TM_TEXASR(r3) 76 mfspr r0, SPRN_TFIAR 77 std r0, THREAD_TM_TFIAR(r3) 78 blr 79 80_GLOBAL(tm_restore_sprs) 81 ld r0, THREAD_TM_TFHAR(r3) 82 mtspr SPRN_TFHAR, r0 83 ld r0, THREAD_TM_TEXASR(r3) 84 mtspr SPRN_TEXASR, r0 85 ld r0, THREAD_TM_TFIAR(r3) 86 mtspr SPRN_TFIAR, r0 87 blr 88 89 /* Passed an 8-bit failure cause as first argument. */ 90_GLOBAL(tm_abort) 91 TABORT(R3) 92 blr 93EXPORT_SYMBOL_GPL(tm_abort); 94 95/* 96 * void tm_reclaim(struct thread_struct *thread, 97 * uint8_t cause) 98 * 99 * - Performs a full reclaim. This destroys outstanding 100 * transactions and updates thread.ckpt_regs, thread.ckfp_state and 101 * thread.ckvr_state with the original checkpointed state. Note that 102 * thread->regs is unchanged. 103 * 104 * Purpose is to both abort transactions of, and preserve the state of, 105 * a transactions at a context switch. We preserve/restore both sets of process 106 * state to restore them when the thread's scheduled again. We continue in 107 * userland as though nothing happened, but when the transaction is resumed 108 * they will abort back to the checkpointed state we save out here. 109 * 110 * Call with IRQs off, stacks get all out of sync for some periods in here! 111 */ 112_GLOBAL(tm_reclaim) 113 mfcr r5 114 mflr r0 115 stw r5, 8(r1) 116 std r0, 16(r1) 117 std r2, STK_GOT(r1) 118 stdu r1, -TM_FRAME_SIZE(r1) 119 120 /* We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD]. */ 121 122 std r3, STK_PARAM(R3)(r1) 123 SAVE_NVGPRS(r1) 124 125 /* 126 * Save kernel live AMR since it will be clobbered by treclaim 127 * but can be used elsewhere later in kernel space. 128 */ 129 mfspr r3, SPRN_AMR 130 std r3, TM_FRAME_L1(r1) 131 132 /* We need to setup MSR for VSX register save instructions. */ 133 mfmsr r14 134 mr r15, r14 135 ori r15, r15, MSR_FP 136 li r16, 0 137 ori r16, r16, MSR_EE /* IRQs hard off */ 138 andc r15, r15, r16 139 oris r15, r15, MSR_VEC@h 140#ifdef CONFIG_VSX 141 BEGIN_FTR_SECTION 142 oris r15,r15, MSR_VSX@h 143 END_FTR_SECTION_IFSET(CPU_FTR_VSX) 144#endif 145 mtmsrd r15 146 std r14, TM_FRAME_L0(r1) 147 148 /* Do sanity check on MSR to make sure we are suspended */ 149 li r7, (MSR_TS_S)@higher 150 srdi r6, r14, 32 151 and r6, r6, r7 1521: tdeqi r6, 0 153 EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 154 155 /* Stash the stack pointer away for use after reclaim */ 156 std r1, PACAR1(r13) 157 158 /* Clear MSR RI since we are about to use SCRATCH0, EE is already off */ 159 li r5, 0 160 mtmsrd r5, 1 161 162 /* 163 * BE CAREFUL HERE: 164 * At this point we can't take an SLB miss since we have MSR_RI 165 * off. Load only to/from the stack/paca which are in SLB bolted regions 166 * until we turn MSR RI back on. 167 * 168 * The moment we treclaim, ALL of our GPRs will switch 169 * to user register state. (FPRs, CCR etc. also!) 170 * Use an sprg and a tm_scratch in the PACA to shuffle. 171 */ 172 TRECLAIM(R4) /* Cause in r4 */ 173 174 /* 175 * ******************** GPRs ******************** 176 * Stash the checkpointed r13 in the scratch SPR and get the real paca. 177 */ 178 SET_SCRATCH0(r13) 179 GET_PACA(r13) 180 181 /* 182 * Stash the checkpointed r1 away in paca->tm_scratch and get the real 183 * stack pointer back into r1. 184 */ 185 std r1, PACATMSCRATCH(r13) 186 ld r1, PACAR1(r13) 187 188 std r11, GPR11(r1) /* Temporary stash */ 189 190 /* 191 * Move the saved user r1 to the kernel stack in case PACATMSCRATCH is 192 * clobbered by an exception once we turn on MSR_RI below. 193 */ 194 ld r11, PACATMSCRATCH(r13) 195 std r11, GPR1(r1) 196 197 /* 198 * Store r13 away so we can free up the scratch SPR for the SLB fault 199 * handler (needed once we start accessing the thread_struct). 200 */ 201 GET_SCRATCH0(r11) 202 std r11, GPR13(r1) 203 204 /* Reset MSR RI so we can take SLB faults again */ 205 li r11, MSR_RI 206 mtmsrd r11, 1 207 208 /* Store the PPR in r11 and reset to decent value */ 209 mfspr r11, SPRN_PPR 210 HMT_MEDIUM 211 212 /* Now get some more GPRS free */ 213 std r7, GPR7(r1) /* Temporary stash */ 214 std r12, GPR12(r1) /* '' '' '' */ 215 ld r12, STK_PARAM(R3)(r1) /* Param 0, thread_struct * */ 216 217 std r11, THREAD_TM_PPR(r12) /* Store PPR and free r11 */ 218 219 addi r7, r12, PT_CKPT_REGS /* Thread's ckpt_regs */ 220 221 /* 222 * Make r7 look like an exception frame so that we can use the neat 223 * GPRx(n) macros. r7 is NOT a pt_regs ptr! 224 */ 225 subi r7, r7, STACK_FRAME_OVERHEAD 226 227 /* Sync the userland GPRs 2-12, 14-31 to thread->regs: */ 228 SAVE_GPR(0, r7) /* user r0 */ 229 SAVE_GPRS(2, 6, r7) /* user r2-r6 */ 230 SAVE_GPRS(8, 10, r7) /* user r8-r10 */ 231 ld r3, GPR1(r1) /* user r1 */ 232 ld r4, GPR7(r1) /* user r7 */ 233 ld r5, GPR11(r1) /* user r11 */ 234 ld r6, GPR12(r1) /* user r12 */ 235 ld r8, GPR13(r1) /* user r13 */ 236 std r3, GPR1(r7) 237 std r4, GPR7(r7) 238 std r5, GPR11(r7) 239 std r6, GPR12(r7) 240 std r8, GPR13(r7) 241 242 SAVE_NVGPRS(r7) /* user r14-r31 */ 243 244 /* ******************** NIP ******************** */ 245 mfspr r3, SPRN_TFHAR 246 std r3, _NIP(r7) /* Returns to failhandler */ 247 /* 248 * The checkpointed NIP is ignored when rescheduling/rechkpting, 249 * but is used in signal return to 'wind back' to the abort handler. 250 */ 251 252 /* ***************** CTR, LR, CR, XER ********** */ 253 mfctr r3 254 mflr r4 255 mfcr r5 256 mfxer r6 257 258 std r3, _CTR(r7) 259 std r4, _LINK(r7) 260 std r5, _CCR(r7) 261 std r6, _XER(r7) 262 263 /* ******************** TAR, DSCR ********** */ 264 mfspr r3, SPRN_TAR 265 mfspr r4, SPRN_DSCR 266 267 std r3, THREAD_TM_TAR(r12) 268 std r4, THREAD_TM_DSCR(r12) 269 270 /* ******************** AMR **************** */ 271 mfspr r3, SPRN_AMR 272 std r3, THREAD_TM_AMR(r12) 273 274 /* 275 * MSR and flags: We don't change CRs, and we don't need to alter MSR. 276 */ 277 278 279 /* 280 * ******************** FPR/VR/VSRs ************ 281 * After reclaiming, capture the checkpointed FPRs/VRs. 282 * 283 * We enabled VEC/FP/VSX in the msr above, so we can execute these 284 * instructions! 285 */ 286 mr r3, r12 287 288 /* Altivec (VEC/VMX/VR)*/ 289 addi r7, r3, THREAD_CKVRSTATE 290 SAVE_32VRS(0, r6, r7) /* r6 scratch, r7 ckvr_state */ 291 mfvscr v0 292 li r6, VRSTATE_VSCR 293 stvx v0, r7, r6 294 295 /* VRSAVE */ 296 mfspr r0, SPRN_VRSAVE 297 std r0, THREAD_CKVRSAVE(r3) 298 299 /* Floating Point (FP) */ 300 addi r7, r3, THREAD_CKFPSTATE 301 SAVE_32FPRS_VSRS(0, R6, R7) /* r6 scratch, r7 ckfp_state */ 302 mffs fr0 303 stfd fr0,FPSTATE_FPSCR(r7) 304 305 306 /* 307 * TM regs, incl TEXASR -- these live in thread_struct. Note they've 308 * been updated by the treclaim, to explain to userland the failure 309 * cause (aborted). 310 */ 311 mfspr r0, SPRN_TEXASR 312 mfspr r3, SPRN_TFHAR 313 mfspr r4, SPRN_TFIAR 314 std r0, THREAD_TM_TEXASR(r12) 315 std r3, THREAD_TM_TFHAR(r12) 316 std r4, THREAD_TM_TFIAR(r12) 317 318 /* Restore kernel live AMR */ 319 ld r8, TM_FRAME_L1(r1) 320 mtspr SPRN_AMR, r8 321 322 /* Restore original MSR/IRQ state & clear TM mode */ 323 ld r14, TM_FRAME_L0(r1) /* Orig MSR */ 324 325 li r15, 0 326 rldimi r14, r15, MSR_TS_LG, (63-MSR_TS_LG)-1 327 mtmsrd r14 328 329 REST_NVGPRS(r1) 330 331 addi r1, r1, TM_FRAME_SIZE 332 lwz r4, 8(r1) 333 ld r0, 16(r1) 334 mtcr r4 335 mtlr r0 336 ld r2, STK_GOT(r1) 337 338 /* Load CPU's default DSCR */ 339 ld r0, PACA_DSCR_DEFAULT(r13) 340 mtspr SPRN_DSCR, r0 341 342 blr 343 344 345 /* 346 * void __tm_recheckpoint(struct thread_struct *thread) 347 * - Restore the checkpointed register state saved by tm_reclaim 348 * when we switch_to a process. 349 * 350 * Call with IRQs off, stacks get all out of sync for 351 * some periods in here! 352 */ 353_GLOBAL(__tm_recheckpoint) 354 mfcr r5 355 mflr r0 356 stw r5, 8(r1) 357 std r0, 16(r1) 358 std r2, STK_GOT(r1) 359 stdu r1, -TM_FRAME_SIZE(r1) 360 361 /* 362 * We've a struct pt_regs at [r1+STACK_FRAME_OVERHEAD]. 363 * This is used for backing up the NVGPRs: 364 */ 365 SAVE_NVGPRS(r1) 366 367 /* 368 * Save kernel live AMR since it will be clobbered for trechkpt 369 * but can be used elsewhere later in kernel space. 370 */ 371 mfspr r8, SPRN_AMR 372 std r8, TM_FRAME_L0(r1) 373 374 /* Load complete register state from ts_ckpt* registers */ 375 376 addi r7, r3, PT_CKPT_REGS /* Thread's ckpt_regs */ 377 378 /* 379 * Make r7 look like an exception frame so that we can use the neat 380 * GPRx(n) macros. r7 is now NOT a pt_regs ptr! 381 */ 382 subi r7, r7, STACK_FRAME_OVERHEAD 383 384 /* We need to setup MSR for FP/VMX/VSX register save instructions. */ 385 mfmsr r6 386 mr r5, r6 387 ori r5, r5, MSR_FP 388#ifdef CONFIG_ALTIVEC 389 oris r5, r5, MSR_VEC@h 390#endif 391#ifdef CONFIG_VSX 392 BEGIN_FTR_SECTION 393 oris r5,r5, MSR_VSX@h 394 END_FTR_SECTION_IFSET(CPU_FTR_VSX) 395#endif 396 mtmsrd r5 397 398#ifdef CONFIG_ALTIVEC 399 /* 400 * FP and VEC registers: These are recheckpointed from 401 * thread.ckfp_state and thread.ckvr_state respectively. The 402 * thread.fp_state[] version holds the 'live' (transactional) 403 * and will be loaded subsequently by any FPUnavailable trap. 404 */ 405 addi r8, r3, THREAD_CKVRSTATE 406 li r5, VRSTATE_VSCR 407 lvx v0, r8, r5 408 mtvscr v0 409 REST_32VRS(0, r5, r8) /* r5 scratch, r8 ptr */ 410 ld r5, THREAD_CKVRSAVE(r3) 411 mtspr SPRN_VRSAVE, r5 412#endif 413 414 addi r8, r3, THREAD_CKFPSTATE 415 lfd fr0, FPSTATE_FPSCR(r8) 416 MTFSF_L(fr0) 417 REST_32FPRS_VSRS(0, R4, R8) 418 419 mtmsr r6 /* FP/Vec off again! */ 420 421restore_gprs: 422 423 /* ****************** CTR, LR, XER ************* */ 424 ld r4, _CTR(r7) 425 ld r5, _LINK(r7) 426 ld r8, _XER(r7) 427 428 mtctr r4 429 mtlr r5 430 mtxer r8 431 432 /* ******************** TAR ******************** */ 433 ld r4, THREAD_TM_TAR(r3) 434 mtspr SPRN_TAR, r4 435 436 /* ******************** AMR ******************** */ 437 ld r4, THREAD_TM_AMR(r3) 438 mtspr SPRN_AMR, r4 439 440 /* Load up the PPR and DSCR in GPRs only at this stage */ 441 ld r5, THREAD_TM_DSCR(r3) 442 ld r6, THREAD_TM_PPR(r3) 443 444 REST_GPR(0, r7) /* GPR0 */ 445 REST_GPRS(2, 4, r7) /* GPR2-4 */ 446 REST_GPRS(8, 31, r7) /* GPR8-31 */ 447 448 /* Load up PPR and DSCR here so we don't run with user values for long */ 449 mtspr SPRN_DSCR, r5 450 mtspr SPRN_PPR, r6 451 452 /* 453 * Do final sanity check on TEXASR to make sure FS is set. Do this 454 * here before we load up the userspace r1 so any bugs we hit will get 455 * a call chain. 456 */ 457 mfspr r5, SPRN_TEXASR 458 srdi r5, r5, 16 459 li r6, (TEXASR_FS)@h 460 and r6, r6, r5 4611: tdeqi r6, 0 462 EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 463 464 /* 465 * Do final sanity check on MSR to make sure we are not transactional 466 * or suspended. 467 */ 468 mfmsr r6 469 li r5, (MSR_TS_MASK)@higher 470 srdi r6, r6, 32 471 and r6, r6, r5 4721: tdnei r6, 0 473 EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0 474 475 /* Restore CR */ 476 ld r6, _CCR(r7) 477 mtcr r6 478 479 REST_GPR(6, r7) 480 481 /* 482 * Store r1 and r5 on the stack so that we can access them after we 483 * clear MSR RI. 484 */ 485 486 REST_GPR(5, r7) 487 std r5, -8(r1) 488 ld r5, GPR1(r7) 489 std r5, -16(r1) 490 491 REST_GPR(7, r7) 492 493 /* Clear MSR RI since we are about to use SCRATCH0. EE is already off */ 494 li r5, 0 495 mtmsrd r5, 1 496 497 /* 498 * BE CAREFUL HERE: 499 * At this point we can't take an SLB miss since we have MSR_RI 500 * off. Load only to/from the stack/paca which are in SLB bolted regions 501 * until we turn MSR RI back on. 502 */ 503 504 SET_SCRATCH0(r1) 505 ld r5, -8(r1) 506 ld r1, -16(r1) 507 508 /* Commit register state as checkpointed state: */ 509 TRECHKPT 510 511 HMT_MEDIUM 512 513 /* 514 * Our transactional state has now changed. 515 * 516 * Now just get out of here. Transactional (current) state will be 517 * updated once restore is called on the return path in the _switch-ed 518 * -to process. 519 */ 520 521 GET_PACA(r13) 522 GET_SCRATCH0(r1) 523 524 /* R1 is restored, so we are recoverable again. EE is still off */ 525 li r4, MSR_RI 526 mtmsrd r4, 1 527 528 /* Restore kernel live AMR */ 529 ld r8, TM_FRAME_L0(r1) 530 mtspr SPRN_AMR, r8 531 532 REST_NVGPRS(r1) 533 534 addi r1, r1, TM_FRAME_SIZE 535 lwz r4, 8(r1) 536 ld r0, 16(r1) 537 mtcr r4 538 mtlr r0 539 ld r2, STK_GOT(r1) 540 541 /* Load CPU's default DSCR */ 542 ld r0, PACA_DSCR_DEFAULT(r13) 543 mtspr SPRN_DSCR, r0 544 545 blr 546 547 /* ****************************************************************** */ 548