arch/powerpc/kernel/process.c

   1 /*
   2  *  Derived from "arch/i386/kernel/process.c"
   3  *    Copyright (C) 1995  Linus Torvalds
   4  *
   5  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
   6  *  Paul Mackerras (paulus@cs.anu.edu.au)
   7  *
   8  *  PowerPC version
   9  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  10  *
  11  *  This program is free software; you can redistribute it and/or
  12  *  modify it under the terms of the GNU General Public License
  13  *  as published by the Free Software Foundation; either version
  14  *  2 of the License, or (at your option) any later version.
  15  */
  16
  17 #include <linux/errno.h>
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/mm.h>
  21 #include <linux/smp.h>
  22 #include <linux/stddef.h>
  23 #include <linux/unistd.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/slab.h>
  26 #include <linux/user.h>
  27 #include <linux/elf.h>
  28 #include <linux/prctl.h>
  29 #include <linux/init_task.h>
  30 #include <linux/export.h>
  31 #include <linux/kallsyms.h>
  32 #include <linux/mqueue.h>
  33 #include <linux/hardirq.h>
  34 #include <linux/utsname.h>
  35 #include <linux/ftrace.h>
  36 #include <linux/kernel_stat.h>
  37 #include <linux/personality.h>
  38 #include <linux/random.h>
  39 #include <linux/hw_breakpoint.h>
  40 #include <linux/uaccess.h>
  41 #include <linux/elf-randomize.h>
  42
  43 #include <asm/pgtable.h>
  44 #include <asm/io.h>
  45 #include <asm/processor.h>
  46 #include <asm/mmu.h>
  47 #include <asm/prom.h>
  48 #include <asm/machdep.h>
  49 #include <asm/time.h>
  50 #include <asm/runlatch.h>
  51 #include <asm/syscalls.h>
  52 #include <asm/switch_to.h>
  53 #include <asm/tm.h>
  54 #include <asm/debug.h>
  55 #ifdef CONFIG_PPC64
  56 #include <asm/firmware.h>
  57 #endif
  58 #include <asm/code-patching.h>
  59 #include <asm/exec.h>
  60 #include <asm/livepatch.h>
  61
  62 #include <linux/kprobes.h>
  63 #include <linux/kdebug.h>
  64
  65 /* Transactional Memory debug */
  66 #ifdef TM_DEBUG_SW
  67 #define TM_DEBUG(x...) printk(KERN_INFO x)
  68 #else
  69 #define TM_DEBUG(x...) do { } while(0)
  70 #endif
  71
  72 extern unsigned long _get_SP(void);
  73
  74 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  75 static void check_if_tm_restore_required(struct task_struct *tsk)
  76 {
  77         /*
  78          * If we are saving the current thread's registers, and the
  79          * thread is in a transactional state, set the TIF_RESTORE_TM
  80          * bit so that we know to restore the registers before
  81          * returning to userspace.
  82          */
  83         if (tsk == current && tsk->thread.regs &&
  84             MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
  85             !test_thread_flag(TIF_RESTORE_TM)) {
  86                 tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
  87                 set_thread_flag(TIF_RESTORE_TM);
  88         }
  89 }
  90 #else
  91 static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
  92 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
  93
  94 bool strict_msr_control;
  95 EXPORT_SYMBOL(strict_msr_control);
  96
  97 static int __init enable_strict_msr_control(char *str)
  98 {
  99         strict_msr_control = true;
 100         pr_info("Enabling strict facility control\n");
 101
 102         return 0;
 103 }
 104 early_param("ppc_strict_facility_enable", enable_strict_msr_control);
 105
 106 void msr_check_and_set(unsigned long bits)
 107 {
 108         unsigned long oldmsr = mfmsr();
 109         unsigned long newmsr;
 110
 111         newmsr = oldmsr | bits;
 112
 113 #ifdef CONFIG_VSX
 114         if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 115                 newmsr |= MSR_VSX;
 116 #endif
 117
 118         if (oldmsr != newmsr)
 119                 mtmsr_isync(newmsr);
 120 }
 121
 122 void __msr_check_and_clear(unsigned long bits)
 123 {
 124         unsigned long oldmsr = mfmsr();
 125         unsigned long newmsr;
 126
 127         newmsr = oldmsr & ~bits;
 128
 129 #ifdef CONFIG_VSX
 130         if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 131                 newmsr &= ~MSR_VSX;
 132 #endif
 133
 134         if (oldmsr != newmsr)
 135                 mtmsr_isync(newmsr);
 136 }
 137 EXPORT_SYMBOL(__msr_check_and_clear);
 138
 139 #ifdef CONFIG_PPC_FPU
 140 void __giveup_fpu(struct task_struct *tsk)
 141 {
 142         save_fpu(tsk);
 143         tsk->thread.regs->msr &= ~MSR_FP;
 144 #ifdef CONFIG_VSX
 145         if (cpu_has_feature(CPU_FTR_VSX))
 146                 tsk->thread.regs->msr &= ~MSR_VSX;
 147 #endif
 148 }
 149
 150 void giveup_fpu(struct task_struct *tsk)
 151 {
 152         check_if_tm_restore_required(tsk);
 153
 154         msr_check_and_set(MSR_FP);
 155         __giveup_fpu(tsk);
 156         msr_check_and_clear(MSR_FP);
 157 }
 158 EXPORT_SYMBOL(giveup_fpu);
 159
 160 /*
 161  * Make sure the floating-point register state in the
 162  * the thread_struct is up to date for task tsk.
 163  */
 164 void flush_fp_to_thread(struct task_struct *tsk)
 165 {
 166         if (tsk->thread.regs) {
 167                 /*
 168                  * We need to disable preemption here because if we didn't,
 169                  * another process could get scheduled after the regs->msr
 170                  * test but before we have finished saving the FP registers
 171                  * to the thread_struct.  That process could take over the
 172                  * FPU, and then when we get scheduled again we would store
 173                  * bogus values for the remaining FP registers.
 174                  */
 175                 preempt_disable();
 176                 if (tsk->thread.regs->msr & MSR_FP) {
 177                         /*
 178                          * This should only ever be called for current or
 179                          * for a stopped child process.  Since we save away
 180                          * the FP register state on context switch,
 181                          * there is something wrong if a stopped child appears
 182                          * to still have its FP state in the CPU registers.
 183                          */
 184                         BUG_ON(tsk != current);
 185                         giveup_fpu(tsk);
 186                 }
 187                 preempt_enable();
 188         }
 189 }
 190 EXPORT_SYMBOL_GPL(flush_fp_to_thread);
 191
 192 void enable_kernel_fp(void)
 193 {
 194         WARN_ON(preemptible());
 195
 196         msr_check_and_set(MSR_FP);
 197
 198         if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
 199                 check_if_tm_restore_required(current);
 200                 __giveup_fpu(current);
 201         }
 202 }
 203 EXPORT_SYMBOL(enable_kernel_fp);
 204
 205 static int restore_fp(struct task_struct *tsk) {
 206         if (tsk->thread.load_fp) {
 207                 load_fp_state(&current->thread.fp_state);
 208                 current->thread.load_fp++;
 209                 return 1;
 210         }
 211         return 0;
 212 }
 213 #else
 214 static int restore_fp(struct task_struct *tsk) { return 0; }
 215 #endif /* CONFIG_PPC_FPU */
 216
 217 #ifdef CONFIG_ALTIVEC
 218 #define loadvec(thr) ((thr).load_vec)
 219
 220 static void __giveup_altivec(struct task_struct *tsk)
 221 {
 222         save_altivec(tsk);
 223         tsk->thread.regs->msr &= ~MSR_VEC;
 224 #ifdef CONFIG_VSX
 225         if (cpu_has_feature(CPU_FTR_VSX))
 226                 tsk->thread.regs->msr &= ~MSR_VSX;
 227 #endif
 228 }
 229
 230 void giveup_altivec(struct task_struct *tsk)
 231 {
 232         check_if_tm_restore_required(tsk);
 233
 234         msr_check_and_set(MSR_VEC);
 235         __giveup_altivec(tsk);
 236         msr_check_and_clear(MSR_VEC);
 237 }
 238 EXPORT_SYMBOL(giveup_altivec);
 239
 240 void enable_kernel_altivec(void)
 241 {
 242         WARN_ON(preemptible());
 243
 244         msr_check_and_set(MSR_VEC);
 245
 246         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
 247                 check_if_tm_restore_required(current);
 248                 __giveup_altivec(current);
 249         }
 250 }
 251 EXPORT_SYMBOL(enable_kernel_altivec);
 252
 253 /*
 254  * Make sure the VMX/Altivec register state in the
 255  * the thread_struct is up to date for task tsk.
 256  */
 257 void flush_altivec_to_thread(struct task_struct *tsk)
 258 {
 259         if (tsk->thread.regs) {
 260                 preempt_disable();
 261                 if (tsk->thread.regs->msr & MSR_VEC) {
 262                         BUG_ON(tsk != current);
 263                         giveup_altivec(tsk);
 264                 }
 265                 preempt_enable();
 266         }
 267 }
 268 EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
 269
 270 static int restore_altivec(struct task_struct *tsk)
 271 {
 272         if (cpu_has_feature(CPU_FTR_ALTIVEC) && tsk->thread.load_vec) {
 273                 load_vr_state(&tsk->thread.vr_state);
 274                 tsk->thread.used_vr = 1;
 275                 tsk->thread.load_vec++;
 276
 277                 return 1;
 278         }
 279         return 0;
 280 }
 281 #else
 282 #define loadvec(thr) 0
 283 static inline int restore_altivec(struct task_struct *tsk) { return 0; }
 284 #endif /* CONFIG_ALTIVEC */
 285
 286 #ifdef CONFIG_VSX
 287 static void __giveup_vsx(struct task_struct *tsk)
 288 {
 289         if (tsk->thread.regs->msr & MSR_FP)
 290                 __giveup_fpu(tsk);
 291         if (tsk->thread.regs->msr & MSR_VEC)
 292                 __giveup_altivec(tsk);
 293         tsk->thread.regs->msr &= ~MSR_VSX;
 294 }
 295
 296 static void giveup_vsx(struct task_struct *tsk)
 297 {
 298         check_if_tm_restore_required(tsk);
 299
 300         msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 301         __giveup_vsx(tsk);
 302         msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
 303 }
 304
 305 static void save_vsx(struct task_struct *tsk)
 306 {
 307         if (tsk->thread.regs->msr & MSR_FP)
 308                 save_fpu(tsk);
 309         if (tsk->thread.regs->msr & MSR_VEC)
 310                 save_altivec(tsk);
 311 }
 312
 313 void enable_kernel_vsx(void)
 314 {
 315         WARN_ON(preemptible());
 316
 317         msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 318
 319         if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
 320                 check_if_tm_restore_required(current);
 321                 if (current->thread.regs->msr & MSR_FP)
 322                         __giveup_fpu(current);
 323                 if (current->thread.regs->msr & MSR_VEC)
 324                         __giveup_altivec(current);
 325                 __giveup_vsx(current);
 326         }
 327 }
 328 EXPORT_SYMBOL(enable_kernel_vsx);
 329
 330 void flush_vsx_to_thread(struct task_struct *tsk)
 331 {
 332         if (tsk->thread.regs) {
 333                 preempt_disable();
 334                 if (tsk->thread.regs->msr & MSR_VSX) {
 335                         BUG_ON(tsk != current);
 336                         giveup_vsx(tsk);
 337                 }
 338                 preempt_enable();
 339         }
 340 }
 341 EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
 342
 343 static int restore_vsx(struct task_struct *tsk)
 344 {
 345         if (cpu_has_feature(CPU_FTR_VSX)) {
 346                 tsk->thread.used_vsr = 1;
 347                 return 1;
 348         }
 349
 350         return 0;
 351 }
 352 #else
 353 static inline int restore_vsx(struct task_struct *tsk) { return 0; }
 354 static inline void save_vsx(struct task_struct *tsk) { }
 355 #endif /* CONFIG_VSX */
 356
 357 #ifdef CONFIG_SPE
 358 void giveup_spe(struct task_struct *tsk)
 359 {
 360         check_if_tm_restore_required(tsk);
 361
 362         msr_check_and_set(MSR_SPE);
 363         __giveup_spe(tsk);
 364         msr_check_and_clear(MSR_SPE);
 365 }
 366 EXPORT_SYMBOL(giveup_spe);
 367
 368 void enable_kernel_spe(void)
 369 {
 370         WARN_ON(preemptible());
 371
 372         msr_check_and_set(MSR_SPE);
 373
 374         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
 375                 check_if_tm_restore_required(current);
 376                 __giveup_spe(current);
 377         }
 378 }
 379 EXPORT_SYMBOL(enable_kernel_spe);
 380
 381 void flush_spe_to_thread(struct task_struct *tsk)
 382 {
 383         if (tsk->thread.regs) {
 384                 preempt_disable();
 385                 if (tsk->thread.regs->msr & MSR_SPE) {
 386                         BUG_ON(tsk != current);
 387                         tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 388                         giveup_spe(tsk);
 389                 }
 390                 preempt_enable();
 391         }
 392 }
 393 #endif /* CONFIG_SPE */
 394
 395 static unsigned long msr_all_available;
 396
 397 static int __init init_msr_all_available(void)
 398 {
 399 #ifdef CONFIG_PPC_FPU
 400         msr_all_available |= MSR_FP;
 401 #endif
 402 #ifdef CONFIG_ALTIVEC
 403         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 404                 msr_all_available |= MSR_VEC;
 405 #endif
 406 #ifdef CONFIG_VSX
 407         if (cpu_has_feature(CPU_FTR_VSX))
 408                 msr_all_available |= MSR_VSX;
 409 #endif
 410 #ifdef CONFIG_SPE
 411         if (cpu_has_feature(CPU_FTR_SPE))
 412                 msr_all_available |= MSR_SPE;
 413 #endif
 414
 415         return 0;
 416 }
 417 early_initcall(init_msr_all_available);
 418
 419 void giveup_all(struct task_struct *tsk)
 420 {
 421         unsigned long usermsr;
 422
 423         if (!tsk->thread.regs)
 424                 return;
 425
 426         usermsr = tsk->thread.regs->msr;
 427
 428         if ((usermsr & msr_all_available) == 0)
 429                 return;
 430
 431         msr_check_and_set(msr_all_available);
 432
 433 #ifdef CONFIG_PPC_FPU
 434         if (usermsr & MSR_FP)
 435                 __giveup_fpu(tsk);
 436 #endif
 437 #ifdef CONFIG_ALTIVEC
 438         if (usermsr & MSR_VEC)
 439                 __giveup_altivec(tsk);
 440 #endif
 441 #ifdef CONFIG_VSX
 442         if (usermsr & MSR_VSX)
 443                 __giveup_vsx(tsk);
 444 #endif
 445 #ifdef CONFIG_SPE
 446         if (usermsr & MSR_SPE)
 447                 __giveup_spe(tsk);
 448 #endif
 449
 450         msr_check_and_clear(msr_all_available);
 451 }
 452 EXPORT_SYMBOL(giveup_all);
 453
 454 void restore_math(struct pt_regs *regs)
 455 {
 456         unsigned long msr;
 457
 458         if (!current->thread.load_fp && !loadvec(current->thread))
 459                 return;
 460
 461         msr = regs->msr;
 462         msr_check_and_set(msr_all_available);
 463
 464         /*
 465          * Only reload if the bit is not set in the user MSR, the bit BEING set
 466          * indicates that the registers are hot
 467          */
 468         if ((!(msr & MSR_FP)) && restore_fp(current))
 469                 msr |= MSR_FP | current->thread.fpexc_mode;
 470
 471         if ((!(msr & MSR_VEC)) && restore_altivec(current))
 472                 msr |= MSR_VEC;
 473
 474         if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
 475                         restore_vsx(current)) {
 476                 msr |= MSR_VSX;
 477         }
 478
 479         msr_check_and_clear(msr_all_available);
 480
 481         regs->msr = msr;
 482 }
 483
 484 void save_all(struct task_struct *tsk)
 485 {
 486         unsigned long usermsr;
 487
 488         if (!tsk->thread.regs)
 489                 return;
 490
 491         usermsr = tsk->thread.regs->msr;
 492
 493         if ((usermsr & msr_all_available) == 0)
 494                 return;
 495
 496         msr_check_and_set(msr_all_available);
 497
 498         /*
 499          * Saving the way the register space is in hardware, save_vsx boils
 500          * down to a save_fpu() and save_altivec()
 501          */
 502         if (usermsr & MSR_VSX) {
 503                 save_vsx(tsk);
 504         } else {
 505                 if (usermsr & MSR_FP)
 506                         save_fpu(tsk);
 507
 508                 if (usermsr & MSR_VEC)
 509                         save_altivec(tsk);
 510         }
 511
 512         if (usermsr & MSR_SPE)
 513                 __giveup_spe(tsk);
 514
 515         msr_check_and_clear(msr_all_available);
 516 }
 517
 518 void flush_all_to_thread(struct task_struct *tsk)
 519 {
 520         if (tsk->thread.regs) {
 521                 preempt_disable();
 522                 BUG_ON(tsk != current);
 523                 save_all(tsk);
 524
 525 #ifdef CONFIG_SPE
 526                 if (tsk->thread.regs->msr & MSR_SPE)
 527                         tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 528 #endif
 529
 530                 preempt_enable();
 531         }
 532 }
 533 EXPORT_SYMBOL(flush_all_to_thread);
 534
 535 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 536 void do_send_trap(struct pt_regs *regs, unsigned long address,
 537                   unsigned long error_code, int signal_code, int breakpt)
 538 {
 539         siginfo_t info;
 540
 541         current->thread.trap_nr = signal_code;
 542         if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 543                         11, SIGSEGV) == NOTIFY_STOP)
 544                 return;
 545
 546         /* Deliver the signal to userspace */
 547         info.si_signo = SIGTRAP;
 548         info.si_errno = breakpt;        /* breakpoint or watchpoint id */
 549         info.si_code = signal_code;
 550         info.si_addr = (void __user *)address;
 551         force_sig_info(SIGTRAP, &info, current);
 552 }
 553 #else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
 554 void do_break (struct pt_regs *regs, unsigned long address,
 555                     unsigned long error_code)
 556 {
 557         siginfo_t info;
 558
 559         current->thread.trap_nr = TRAP_HWBKPT;
 560         if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 561                         11, SIGSEGV) == NOTIFY_STOP)
 562                 return;
 563
 564         if (debugger_break_match(regs))
 565                 return;
 566
 567         /* Clear the breakpoint */
 568         hw_breakpoint_disable();
 569
 570         /* Deliver the signal to userspace */
 571         info.si_signo = SIGTRAP;
 572         info.si_errno = 0;
 573         info.si_code = TRAP_HWBKPT;
 574         info.si_addr = (void __user *)address;
 575         force_sig_info(SIGTRAP, &info, current);
 576 }
 577 #endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
 578
 579 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
 580
 581 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 582 /*
 583  * Set the debug registers back to their default "safe" values.
 584  */
 585 static void set_debug_reg_defaults(struct thread_struct *thread)
 586 {
 587         thread->debug.iac1 = thread->debug.iac2 = 0;
 588 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
 589         thread->debug.iac3 = thread->debug.iac4 = 0;
 590 #endif
 591         thread->debug.dac1 = thread->debug.dac2 = 0;
 592 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 593         thread->debug.dvc1 = thread->debug.dvc2 = 0;
 594 #endif
 595         thread->debug.dbcr0 = 0;
 596 #ifdef CONFIG_BOOKE
 597         /*
 598          * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
 599          */
 600         thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
 601                         DBCR1_IAC3US | DBCR1_IAC4US;
 602         /*
 603          * Force Data Address Compare User/Supervisor bits to be User-only
 604          * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
 605          */
 606         thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
 607 #else
 608         thread->debug.dbcr1 = 0;
 609 #endif
 610 }
 611
 612 static void prime_debug_regs(struct debug_reg *debug)
 613 {
 614         /*
 615          * We could have inherited MSR_DE from userspace, since
 616          * it doesn't get cleared on exception entry.  Make sure
 617          * MSR_DE is clear before we enable any debug events.
 618          */
 619         mtmsr(mfmsr() & ~MSR_DE);
 620
 621         mtspr(SPRN_IAC1, debug->iac1);
 622         mtspr(SPRN_IAC2, debug->iac2);
 623 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
 624         mtspr(SPRN_IAC3, debug->iac3);
 625         mtspr(SPRN_IAC4, debug->iac4);
 626 #endif
 627         mtspr(SPRN_DAC1, debug->dac1);
 628         mtspr(SPRN_DAC2, debug->dac2);
 629 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 630         mtspr(SPRN_DVC1, debug->dvc1);
 631         mtspr(SPRN_DVC2, debug->dvc2);
 632 #endif
 633         mtspr(SPRN_DBCR0, debug->dbcr0);
 634         mtspr(SPRN_DBCR1, debug->dbcr1);
 635 #ifdef CONFIG_BOOKE
 636         mtspr(SPRN_DBCR2, debug->dbcr2);
 637 #endif
 638 }
 639 /*
 640  * Unless neither the old or new thread are making use of the
 641  * debug registers, set the debug registers from the values
 642  * stored in the new thread.
 643  */
 644 void switch_booke_debug_regs(struct debug_reg *new_debug)
 645 {
 646         if ((current->thread.debug.dbcr0 & DBCR0_IDM)
 647                 || (new_debug->dbcr0 & DBCR0_IDM))
 648                         prime_debug_regs(new_debug);
 649 }
 650 EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
 651 #else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
 652 #ifndef CONFIG_HAVE_HW_BREAKPOINT
 653 static void set_debug_reg_defaults(struct thread_struct *thread)
 654 {
 655         thread->hw_brk.address = 0;
 656         thread->hw_brk.type = 0;
 657         set_breakpoint(&thread->hw_brk);
 658 }
 659 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 660 #endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
 661
 662 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 663 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 664 {
 665         mtspr(SPRN_DAC1, dabr);
 666 #ifdef CONFIG_PPC_47x
 667         isync();
 668 #endif
 669         return 0;
 670 }
 671 #elif defined(CONFIG_PPC_BOOK3S)
 672 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 673 {
 674         mtspr(SPRN_DABR, dabr);
 675         if (cpu_has_feature(CPU_FTR_DABRX))
 676                 mtspr(SPRN_DABRX, dabrx);
 677         return 0;
 678 }
 679 #else
 680 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 681 {
 682         return -EINVAL;
 683 }
 684 #endif
 685
 686 static inline int set_dabr(struct arch_hw_breakpoint *brk)
 687 {
 688         unsigned long dabr, dabrx;
 689
 690         dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
 691         dabrx = ((brk->type >> 3) & 0x7);
 692
 693         if (ppc_md.set_dabr)
 694                 return ppc_md.set_dabr(dabr, dabrx);
 695
 696         return __set_dabr(dabr, dabrx);
 697 }
 698
 699 static inline int set_dawr(struct arch_hw_breakpoint *brk)
 700 {
 701         unsigned long dawr, dawrx, mrd;
 702
 703         dawr = brk->address;
 704
 705         dawrx  = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
 706                                    << (63 - 58); //* read/write bits */
 707         dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
 708                                    << (63 - 59); //* translate */
 709         dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
 710                                    >> 3; //* PRIM bits */
 711         /* dawr length is stored in field MDR bits 48:53.  Matches range in
 712            doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
 713            0b111111=64DW.
 714            brk->len is in bytes.
 715            This aligns up to double word size, shifts and does the bias.
 716         */
 717         mrd = ((brk->len + 7) >> 3) - 1;
 718         dawrx |= (mrd & 0x3f) << (63 - 53);
 719
 720         if (ppc_md.set_dawr)
 721                 return ppc_md.set_dawr(dawr, dawrx);
 722         mtspr(SPRN_DAWR, dawr);
 723         mtspr(SPRN_DAWRX, dawrx);
 724         return 0;
 725 }
 726
 727 void __set_breakpoint(struct arch_hw_breakpoint *brk)
 728 {
 729         memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
 730
 731         if (cpu_has_feature(CPU_FTR_DAWR))
 732                 set_dawr(brk);
 733         else
 734                 set_dabr(brk);
 735 }
 736
 737 void set_breakpoint(struct arch_hw_breakpoint *brk)
 738 {
 739         preempt_disable();
 740         __set_breakpoint(brk);
 741         preempt_enable();
 742 }
 743
 744 #ifdef CONFIG_PPC64
 745 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
 746 #endif
 747
 748 static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
 749                               struct arch_hw_breakpoint *b)
 750 {
 751         if (a->address != b->address)
 752                 return false;
 753         if (a->type != b->type)
 754                 return false;
 755         if (a->len != b->len)
 756                 return false;
 757         return true;
 758 }
 759
 760 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 761 static void tm_reclaim_thread(struct thread_struct *thr,
 762                               struct thread_info *ti, uint8_t cause)
 763 {
 764         unsigned long msr_diff = 0;
 765
 766         /*
 767          * If FP/VSX registers have been already saved to the
 768          * thread_struct, move them to the transact_fp array.
 769          * We clear the TIF_RESTORE_TM bit since after the reclaim
 770          * the thread will no longer be transactional.
 771          */
 772         if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) {
 773                 msr_diff = thr->ckpt_regs.msr & ~thr->regs->msr;
 774                 if (msr_diff & MSR_FP)
 775                         memcpy(&thr->transact_fp, &thr->fp_state,
 776                                sizeof(struct thread_fp_state));
 777                 if (msr_diff & MSR_VEC)
 778                         memcpy(&thr->transact_vr, &thr->vr_state,
 779                                sizeof(struct thread_vr_state));
 780                 clear_ti_thread_flag(ti, TIF_RESTORE_TM);
 781                 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;
 782         }
 783
 784         /*
 785          * Use the current MSR TM suspended bit to track if we have
 786          * checkpointed state outstanding.
 787          * On signal delivery, we'd normally reclaim the checkpointed
 788          * state to obtain stack pointer (see:get_tm_stackpointer()).
 789          * This will then directly return to userspace without going
 790          * through __switch_to(). However, if the stack frame is bad,
 791          * we need to exit this thread which calls __switch_to() which
 792          * will again attempt to reclaim the already saved tm state.
 793          * Hence we need to check that we've not already reclaimed
 794          * this state.
 795          * We do this using the current MSR, rather tracking it in
 796          * some specific thread_struct bit, as it has the additional
 797          * benifit of checking for a potential TM bad thing exception.
 798          */
 799         if (!MSR_TM_SUSPENDED(mfmsr()))
 800                 return;
 801
 802         tm_reclaim(thr, thr->regs->msr, cause);
 803
 804         /* Having done the reclaim, we now have the checkpointed
 805          * FP/VSX values in the registers.  These might be valid
 806          * even if we have previously called enable_kernel_fp() or
 807          * flush_fp_to_thread(), so update thr->regs->msr to
 808          * indicate their current validity.
 809          */
 810         thr->regs->msr |= msr_diff;
 811 }
 812
 813 void tm_reclaim_current(uint8_t cause)
 814 {
 815         tm_enable();
 816         tm_reclaim_thread(&current->thread, current_thread_info(), cause);
 817 }
 818
 819 static inline void tm_reclaim_task(struct task_struct *tsk)
 820 {
 821         /* We have to work out if we're switching from/to a task that's in the
 822          * middle of a transaction.
 823          *
 824          * In switching we need to maintain a 2nd register state as
 825          * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
 826          * checkpointed (tbegin) state in ckpt_regs and saves the transactional
 827          * (current) FPRs into oldtask->thread.transact_fpr[].
 828          *
 829          * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
 830          */
 831         struct thread_struct *thr = &tsk->thread;
 832
 833         if (!thr->regs)
 834                 return;
 835
 836         if (!MSR_TM_ACTIVE(thr->regs->msr))
 837                 goto out_and_saveregs;
 838
 839         /* Stash the original thread MSR, as giveup_fpu et al will
 840          * modify it.  We hold onto it to see whether the task used
 841          * FP & vector regs.  If the TIF_RESTORE_TM flag is set,
 842          * ckpt_regs.msr is already set.
 843          */
 844         if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM))
 845                 thr->ckpt_regs.msr = thr->regs->msr;
 846
 847         TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
 848                  "ccr=%lx, msr=%lx, trap=%lx)\n",
 849                  tsk->pid, thr->regs->nip,
 850                  thr->regs->ccr, thr->regs->msr,
 851                  thr->regs->trap);
 852
 853         tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED);
 854
 855         TM_DEBUG("--- tm_reclaim on pid %d complete\n",
 856                  tsk->pid);
 857
 858 out_and_saveregs:
 859         /* Always save the regs here, even if a transaction's not active.
 860          * This context-switches a thread's TM info SPRs.  We do it here to
 861          * be consistent with the restore path (in recheckpoint) which
 862          * cannot happen later in _switch().
 863          */
 864         tm_save_sprs(thr);
 865 }
 866
 867 extern void __tm_recheckpoint(struct thread_struct *thread,
 868                               unsigned long orig_msr);
 869
 870 void tm_recheckpoint(struct thread_struct *thread,
 871                      unsigned long orig_msr)
 872 {
 873         unsigned long flags;
 874
 875         /* We really can't be interrupted here as the TEXASR registers can't
 876          * change and later in the trecheckpoint code, we have a userspace R1.
 877          * So let's hard disable over this region.
 878          */
 879         local_irq_save(flags);
 880         hard_irq_disable();
 881
 882         /* The TM SPRs are restored here, so that TEXASR.FS can be set
 883          * before the trecheckpoint and no explosion occurs.
 884          */
 885         tm_restore_sprs(thread);
 886
 887         __tm_recheckpoint(thread, orig_msr);
 888
 889         local_irq_restore(flags);
 890 }
 891
 892 static inline void tm_recheckpoint_new_task(struct task_struct *new)
 893 {
 894         unsigned long msr;
 895
 896         if (!cpu_has_feature(CPU_FTR_TM))
 897                 return;
 898
 899         /* Recheckpoint the registers of the thread we're about to switch to.
 900          *
 901          * If the task was using FP, we non-lazily reload both the original and
 902          * the speculative FP register states.  This is because the kernel
 903          * doesn't see if/when a TM rollback occurs, so if we take an FP
 904          * unavoidable later, we are unable to determine which set of FP regs
 905          * need to be restored.
 906          */
 907         if (!new->thread.regs)
 908                 return;
 909
 910         if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
 911                 tm_restore_sprs(&new->thread);
 912                 return;
 913         }
 914         msr = new->thread.ckpt_regs.msr;
 915         /* Recheckpoint to restore original checkpointed register state. */
 916         TM_DEBUG("*** tm_recheckpoint of pid %d "
 917                  "(new->msr 0x%lx, new->origmsr 0x%lx)\n",
 918                  new->pid, new->thread.regs->msr, msr);
 919
 920         /* This loads the checkpointed FP/VEC state, if used */
 921         tm_recheckpoint(&new->thread, msr);
 922
 923         /* This loads the speculative FP/VEC state, if used */
 924         if (msr & MSR_FP) {
 925                 do_load_up_transact_fpu(&new->thread);
 926                 new->thread.regs->msr |=
 927                         (MSR_FP | new->thread.fpexc_mode);
 928         }
 929 #ifdef CONFIG_ALTIVEC
 930         if (msr & MSR_VEC) {
 931                 do_load_up_transact_altivec(&new->thread);
 932                 new->thread.regs->msr |= MSR_VEC;
 933         }
 934 #endif
 935         /* We may as well turn on VSX too since all the state is restored now */
 936         if (msr & MSR_VSX)
 937                 new->thread.regs->msr |= MSR_VSX;
 938
 939         TM_DEBUG("*** tm_recheckpoint of pid %d complete "
 940                  "(kernel msr 0x%lx)\n",
 941                  new->pid, mfmsr());
 942 }
 943
 944 static inline void __switch_to_tm(struct task_struct *prev)
 945 {
 946         if (cpu_has_feature(CPU_FTR_TM)) {
 947                 tm_enable();
 948                 tm_reclaim_task(prev);
 949         }
 950 }
 951
 952 /*
 953  * This is called if we are on the way out to userspace and the
 954  * TIF_RESTORE_TM flag is set.  It checks if we need to reload
 955  * FP and/or vector state and does so if necessary.
 956  * If userspace is inside a transaction (whether active or
 957  * suspended) and FP/VMX/VSX instructions have ever been enabled
 958  * inside that transaction, then we have to keep them enabled
 959  * and keep the FP/VMX/VSX state loaded while ever the transaction
 960  * continues.  The reason is that if we didn't, and subsequently
 961  * got a FP/VMX/VSX unavailable interrupt inside a transaction,
 962  * we don't know whether it's the same transaction, and thus we
 963  * don't know which of the checkpointed state and the transactional
 964  * state to use.
 965  */
 966 void restore_tm_state(struct pt_regs *regs)
 967 {
 968         unsigned long msr_diff;
 969
 970         clear_thread_flag(TIF_RESTORE_TM);
 971         if (!MSR_TM_ACTIVE(regs->msr))
 972                 return;
 973
 974         msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
 975         msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
 976
 977         restore_math(regs);
 978
 979         regs->msr |= msr_diff;
 980 }
 981
 982 #else
 983 #define tm_recheckpoint_new_task(new)
 984 #define __switch_to_tm(prev)
 985 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 986
 987 static inline void save_sprs(struct thread_struct *t)
 988 {
 989 #ifdef CONFIG_ALTIVEC
 990         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 991                 t->vrsave = mfspr(SPRN_VRSAVE);
 992 #endif
 993 #ifdef CONFIG_PPC_BOOK3S_64
 994         if (cpu_has_feature(CPU_FTR_DSCR))
 995                 t->dscr = mfspr(SPRN_DSCR);
 996
 997         if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
 998                 t->bescr = mfspr(SPRN_BESCR);
 999                 t->ebbhr = mfspr(SPRN_EBBHR);
1000                 t->ebbrr = mfspr(SPRN_EBBRR);
1001
1002                 t->fscr = mfspr(SPRN_FSCR);
1003
1004                 /*
1005                  * Note that the TAR is not available for use in the kernel.
1006                  * (To provide this, the TAR should be backed up/restored on
1007                  * exception entry/exit instead, and be in pt_regs.  FIXME,
1008                  * this should be in pt_regs anyway (for debug).)
1009                  */
1010                 t->tar = mfspr(SPRN_TAR);
1011         }
1012 #endif
1013 }
1014
1015 static inline void restore_sprs(struct thread_struct *old_thread,
1016                                 struct thread_struct *new_thread)
1017 {
1018 #ifdef CONFIG_ALTIVEC
1019         if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
1020             old_thread->vrsave != new_thread->vrsave)
1021                 mtspr(SPRN_VRSAVE, new_thread->vrsave);
1022 #endif
1023 #ifdef CONFIG_PPC_BOOK3S_64
1024         if (cpu_has_feature(CPU_FTR_DSCR)) {
1025                 u64 dscr = get_paca()->dscr_default;
1026                 u64 fscr = old_thread->fscr & ~FSCR_DSCR;
1027
1028                 if (new_thread->dscr_inherit) {
1029                         dscr = new_thread->dscr;
1030                         fscr |= FSCR_DSCR;
1031                 }
1032
1033                 if (old_thread->dscr != dscr)
1034                         mtspr(SPRN_DSCR, dscr);
1035
1036                 if (old_thread->fscr != fscr)
1037                         mtspr(SPRN_FSCR, fscr);
1038         }
1039
1040         if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1041                 if (old_thread->bescr != new_thread->bescr)
1042                         mtspr(SPRN_BESCR, new_thread->bescr);
1043                 if (old_thread->ebbhr != new_thread->ebbhr)
1044                         mtspr(SPRN_EBBHR, new_thread->ebbhr);
1045                 if (old_thread->ebbrr != new_thread->ebbrr)
1046                         mtspr(SPRN_EBBRR, new_thread->ebbrr);
1047
1048                 if (old_thread->tar != new_thread->tar)
1049                         mtspr(SPRN_TAR, new_thread->tar);
1050         }
1051 #endif
1052 }
1053
1054 struct task_struct *__switch_to(struct task_struct *prev,
1055         struct task_struct *new)
1056 {
1057         struct thread_struct *new_thread, *old_thread;
1058         struct task_struct *last;
1059 #ifdef CONFIG_PPC_BOOK3S_64
1060         struct ppc64_tlb_batch *batch;
1061 #endif
1062
1063         new_thread = &new->thread;
1064         old_thread = &current->thread;
1065
1066         WARN_ON(!irqs_disabled());
1067
1068 #ifdef CONFIG_PPC64
1069         /*
1070          * Collect processor utilization data per process
1071          */
1072         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
1073                 struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
1074                 long unsigned start_tb, current_tb;
1075                 start_tb = old_thread->start_tb;
1076                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
1077                 old_thread->accum_tb += (current_tb - start_tb);
1078                 new_thread->start_tb = current_tb;
1079         }
1080 #endif /* CONFIG_PPC64 */
1081
1082 #ifdef CONFIG_PPC_BOOK3S_64
1083         batch = this_cpu_ptr(&ppc64_tlb_batch);
1084         if (batch->active) {
1085                 current_thread_info()->local_flags |= _TLF_LAZY_MMU;
1086                 if (batch->index)
1087                         __flush_tlb_pending(batch);
1088                 batch->active = 0;
1089         }
1090 #endif /* CONFIG_PPC_BOOK3S_64 */
1091
1092 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1093         switch_booke_debug_regs(&new->thread.debug);
1094 #else
1095 /*
1096  * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1097  * schedule DABR
1098  */
1099 #ifndef CONFIG_HAVE_HW_BREAKPOINT
1100         if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
1101                 __set_breakpoint(&new->thread.hw_brk);
1102 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1103 #endif
1104
1105         /*
1106          * We need to save SPRs before treclaim/trecheckpoint as these will
1107          * change a number of them.
1108          */
1109         save_sprs(&prev->thread);
1110
1111         __switch_to_tm(prev);
1112
1113         /* Save FPU, Altivec, VSX and SPE state */
1114         giveup_all(prev);
1115
1116         /*
1117          * We can't take a PMU exception inside _switch() since there is a
1118          * window where the kernel stack SLB and the kernel stack are out
1119          * of sync. Hard disable here.
1120          */
1121         hard_irq_disable();
1122
1123         tm_recheckpoint_new_task(new);
1124
1125         /*
1126          * Call restore_sprs() before calling _switch(). If we move it after
1127          * _switch() then we miss out on calling it for new tasks. The reason
1128          * for this is we manually create a stack frame for new tasks that
1129          * directly returns through ret_from_fork() or
1130          * ret_from_kernel_thread(). See copy_thread() for details.
1131          */
1132         restore_sprs(old_thread, new_thread);
1133
1134         last = _switch(old_thread, new_thread);
1135
1136 #ifdef CONFIG_PPC_BOOK3S_64
1137         if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
1138                 current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
1139                 batch = this_cpu_ptr(&ppc64_tlb_batch);
1140                 batch->active = 1;
1141         }
1142
1143         if (current_thread_info()->task->thread.regs)
1144                 restore_math(current_thread_info()->task->thread.regs);
1145
1146 #endif /* CONFIG_PPC_BOOK3S_64 */
1147
1148         return last;
1149 }
1150
1151 static int instructions_to_print = 16;
1152
1153 static void show_instructions(struct pt_regs *regs)
1154 {
1155         int i;
1156         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
1157                         sizeof(int));
1158
1159         printk("Instruction dump:");
1160
1161         for (i = 0; i < instructions_to_print; i++) {
1162                 int instr;
1163
1164                 if (!(i % 8))
1165                         printk("\n");
1166
1167 #if !defined(CONFIG_BOOKE)
1168                 /* If executing with the IMMU off, adjust pc rather
1169                  * than print XXXXXXXX.
1170                  */
1171                 if (!(regs->msr & MSR_IR))
1172                         pc = (unsigned long)phys_to_virt(pc);
1173 #endif
1174
1175                 if (!__kernel_text_address(pc) ||
1176                      probe_kernel_address((unsigned int __user *)pc, instr)) {
1177                         printk(KERN_CONT "XXXXXXXX ");
1178                 } else {
1179                         if (regs->nip == pc)
1180                                 printk(KERN_CONT "<%08x> ", instr);
1181                         else
1182                                 printk(KERN_CONT "%08x ", instr);
1183                 }
1184
1185                 pc += sizeof(int);
1186         }
1187
1188         printk("\n");
1189 }
1190
1191 struct regbit {
1192         unsigned long bit;
1193         const char *name;
1194 };
1195
1196 static struct regbit msr_bits[] = {
1197 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1198         {MSR_SF,        "SF"},
1199         {MSR_HV,        "HV"},
1200 #endif
1201         {MSR_VEC,       "VEC"},
1202         {MSR_VSX,       "VSX"},
1203 #ifdef CONFIG_BOOKE
1204         {MSR_CE,        "CE"},
1205 #endif
1206         {MSR_EE,        "EE"},
1207         {MSR_PR,        "PR"},
1208         {MSR_FP,        "FP"},
1209         {MSR_ME,        "ME"},
1210 #ifdef CONFIG_BOOKE
1211         {MSR_DE,        "DE"},
1212 #else
1213         {MSR_SE,        "SE"},
1214         {MSR_BE,        "BE"},
1215 #endif
1216         {MSR_IR,        "IR"},
1217         {MSR_DR,        "DR"},
1218         {MSR_PMM,       "PMM"},
1219 #ifndef CONFIG_BOOKE
1220         {MSR_RI,        "RI"},
1221         {MSR_LE,        "LE"},
1222 #endif
1223         {0,             NULL}
1224 };
1225
1226 static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1227 {
1228         const char *s = "";
1229
1230         for (; bits->bit; ++bits)
1231                 if (val & bits->bit) {
1232                         printk("%s%s", s, bits->name);
1233                         s = sep;
1234                 }
1235 }
1236
1237 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1238 static struct regbit msr_tm_bits[] = {
1239         {MSR_TS_T,      "T"},
1240         {MSR_TS_S,      "S"},
1241         {MSR_TM,        "E"},
1242         {0,             NULL}
1243 };
1244
1245 static void print_tm_bits(unsigned long val)
1246 {
1247 /*
1248  * This only prints something if at least one of the TM bit is set.
1249  * Inside the TM[], the output means:
1250  *   E: Enabled         (bit 32)
1251  *   S: Suspended       (bit 33)
1252  *   T: Transactional   (bit 34)
1253  */
1254         if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1255                 printk(",TM[");
1256                 print_bits(val, msr_tm_bits, "");
1257                 printk("]");
1258         }
1259 }
1260 #else
1261 static void print_tm_bits(unsigned long val) {}
1262 #endif
1263
1264 static void print_msr_bits(unsigned long val)
1265 {
1266         printk("<");
1267         print_bits(val, msr_bits, ",");
1268         print_tm_bits(val);
1269         printk(">");
1270 }
1271
1272 #ifdef CONFIG_PPC64
1273 #define REG             "%016lx"
1274 #define REGS_PER_LINE   4
1275 #define LAST_VOLATILE   13
1276 #else
1277 #define REG             "%08lx"
1278 #define REGS_PER_LINE   8
1279 #define LAST_VOLATILE   12
1280 #endif
1281
1282 void show_regs(struct pt_regs * regs)
1283 {
1284         int i, trap;
1285
1286         show_regs_print_info(KERN_DEFAULT);
1287
1288         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
1289                regs->nip, regs->link, regs->ctr);
1290         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
1291                regs, regs->trap, print_tainted(), init_utsname()->release);
1292         printk("MSR: "REG" ", regs->msr);
1293         print_msr_bits(regs->msr);
1294         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
1295         trap = TRAP(regs);
1296         if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
1297                 printk("CFAR: "REG" ", regs->orig_gpr3);
1298         if (trap == 0x200 || trap == 0x300 || trap == 0x600)
1299 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
1300                 printk("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
1301 #else
1302                 printk("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1303 #endif
1304 #ifdef CONFIG_PPC64
1305         printk("SOFTE: %ld ", regs->softe);
1306 #endif
1307 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1308         if (MSR_TM_ACTIVE(regs->msr))
1309                 printk("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1310 #endif
1311
1312         for (i = 0;  i < 32;  i++) {
1313                 if ((i % REGS_PER_LINE) == 0)
1314                         printk("\nGPR%02d: ", i);
1315                 printk(REG " ", regs->gpr[i]);
1316                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
1317                         break;
1318         }
1319         printk("\n");
1320 #ifdef CONFIG_KALLSYMS
1321         /*
1322          * Lookup NIP late so we have the best change of getting the
1323          * above info out without failing
1324          */
1325         printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1326         printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1327 #endif
1328         show_stack(current, (unsigned long *) regs->gpr[1]);
1329         if (!user_mode(regs))
1330                 show_instructions(regs);
1331 }
1332
1333 void exit_thread(void)
1334 {
1335 }
1336
1337 void flush_thread(void)
1338 {
1339 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1340         flush_ptrace_hw_breakpoint(current);
1341 #else /* CONFIG_HAVE_HW_BREAKPOINT */
1342         set_debug_reg_defaults(&current->thread);
1343 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1344 }
1345
1346 void
1347 release_thread(struct task_struct *t)
1348 {
1349 }
1350
1351 /*
1352  * this gets called so that we can store coprocessor state into memory and
1353  * copy the current task into the new thread.
1354  */
1355 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1356 {
1357         flush_all_to_thread(src);
1358         /*
1359          * Flush TM state out so we can copy it.  __switch_to_tm() does this
1360          * flush but it removes the checkpointed state from the current CPU and
1361          * transitions the CPU out of TM mode.  Hence we need to call
1362          * tm_recheckpoint_new_task() (on the same task) to restore the
1363          * checkpointed state back and the TM mode.
1364          */
1365         __switch_to_tm(src);
1366         tm_recheckpoint_new_task(src);
1367
1368         *dst = *src;
1369
1370         clear_task_ebb(dst);
1371
1372         return 0;
1373 }
1374
1375 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1376 {
1377 #ifdef CONFIG_PPC_STD_MMU_64
1378         unsigned long sp_vsid;
1379         unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1380
1381         if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1382                 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1383                         << SLB_VSID_SHIFT_1T;
1384         else
1385                 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1386                         << SLB_VSID_SHIFT;
1387         sp_vsid |= SLB_VSID_KERNEL | llp;
1388         p->thread.ksp_vsid = sp_vsid;
1389 #endif
1390 }
1391
1392 /*
1393  * Copy a thread..
1394  */
1395
1396 /*
1397  * Copy architecture-specific thread state
1398  */
1399 int copy_thread(unsigned long clone_flags, unsigned long usp,
1400                 unsigned long kthread_arg, struct task_struct *p)
1401 {
1402         struct pt_regs *childregs, *kregs;
1403         extern void ret_from_fork(void);
1404         extern void ret_from_kernel_thread(void);
1405         void (*f)(void);
1406         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1407         struct thread_info *ti = task_thread_info(p);
1408
1409         klp_init_thread_info(ti);
1410
1411         /* Copy registers */
1412         sp -= sizeof(struct pt_regs);
1413         childregs = (struct pt_regs *) sp;
1414         if (unlikely(p->flags & PF_KTHREAD)) {
1415                 /* kernel thread */
1416                 memset(childregs, 0, sizeof(struct pt_regs));
1417                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
1418                 /* function */
1419                 if (usp)
1420                         childregs->gpr[14] = ppc_function_entry((void *)usp);
1421 #ifdef CONFIG_PPC64
1422                 clear_tsk_thread_flag(p, TIF_32BIT);
1423                 childregs->softe = 1;
1424 #endif
1425                 childregs->gpr[15] = kthread_arg;
1426                 p->thread.regs = NULL;  /* no user register state */
1427                 ti->flags |= _TIF_RESTOREALL;
1428                 f = ret_from_kernel_thread;
1429         } else {
1430                 /* user thread */
1431                 struct pt_regs *regs = current_pt_regs();
1432                 CHECK_FULL_REGS(regs);
1433                 *childregs = *regs;
1434                 if (usp)
1435                         childregs->gpr[1] = usp;
1436                 p->thread.regs = childregs;
1437                 childregs->gpr[3] = 0;  /* Result from fork() */
1438                 if (clone_flags & CLONE_SETTLS) {
1439 #ifdef CONFIG_PPC64
1440                         if (!is_32bit_task())
1441                                 childregs->gpr[13] = childregs->gpr[6];
1442                         else
1443 #endif
1444                                 childregs->gpr[2] = childregs->gpr[6];
1445                 }
1446
1447                 f = ret_from_fork;
1448         }
1449         childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1450         sp -= STACK_FRAME_OVERHEAD;
1451
1452         /*
1453          * The way this works is that at some point in the future
1454          * some task will call _switch to switch to the new task.
1455          * That will pop off the stack frame created below and start
1456          * the new task running at ret_from_fork.  The new task will
1457          * do some house keeping and then return from the fork or clone
1458          * system call, using the stack frame created above.
1459          */
1460         ((unsigned long *)sp)[0] = 0;
1461         sp -= sizeof(struct pt_regs);
1462         kregs = (struct pt_regs *) sp;
1463         sp -= STACK_FRAME_OVERHEAD;
1464         p->thread.ksp = sp;
1465 #ifdef CONFIG_PPC32
1466         p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
1467                                 _ALIGN_UP(sizeof(struct thread_info), 16);
1468 #endif
1469 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1470         p->thread.ptrace_bps[0] = NULL;
1471 #endif
1472
1473         p->thread.fp_save_area = NULL;
1474 #ifdef CONFIG_ALTIVEC
1475         p->thread.vr_save_area = NULL;
1476 #endif
1477
1478         setup_ksp_vsid(p, sp);
1479
1480 #ifdef CONFIG_PPC64
1481         if (cpu_has_feature(CPU_FTR_DSCR)) {
1482                 p->thread.dscr_inherit = current->thread.dscr_inherit;
1483                 p->thread.dscr = mfspr(SPRN_DSCR);
1484         }
1485         if (cpu_has_feature(CPU_FTR_HAS_PPR))
1486                 p->thread.ppr = INIT_PPR;
1487 #endif
1488         kregs->nip = ppc_function_entry(f);
1489         return 0;
1490 }
1491
1492 /*
1493  * Set up a thread for executing a new program
1494  */
1495 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1496 {
1497 #ifdef CONFIG_PPC64
1498         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
1499 #endif
1500
1501         /*
1502          * If we exec out of a kernel thread then thread.regs will not be
1503          * set.  Do it now.
1504          */
1505         if (!current->thread.regs) {
1506                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1507                 current->thread.regs = regs - 1;
1508         }
1509
1510         memset(regs->gpr, 0, sizeof(regs->gpr));
1511         regs->ctr = 0;
1512         regs->link = 0;
1513         regs->xer = 0;
1514         regs->ccr = 0;
1515         regs->gpr[1] = sp;
1516
1517         /*
1518          * We have just cleared all the nonvolatile GPRs, so make
1519          * FULL_REGS(regs) return true.  This is necessary to allow
1520          * ptrace to examine the thread immediately after exec.
1521          */
1522         regs->trap &= ~1UL;
1523
1524 #ifdef CONFIG_PPC32
1525         regs->mq = 0;
1526         regs->nip = start;
1527         regs->msr = MSR_USER;
1528 #else
1529         if (!is_32bit_task()) {
1530                 unsigned long entry;
1531
1532                 if (is_elf2_task()) {
1533                         /* Look ma, no function descriptors! */
1534                         entry = start;
1535
1536                         /*
1537                          * Ulrich says:
1538                          *   The latest iteration of the ABI requires that when
1539                          *   calling a function (at its global entry point),
1540                          *   the caller must ensure r12 holds the entry point
1541                          *   address (so that the function can quickly
1542                          *   establish addressability).
1543                          */
1544                         regs->gpr[12] = start;
1545                         /* Make sure that's restored on entry to userspace. */
1546                         set_thread_flag(TIF_RESTOREALL);
1547                 } else {
1548                         unsigned long toc;
1549
1550                         /* start is a relocated pointer to the function
1551                          * descriptor for the elf _start routine.  The first
1552                          * entry in the function descriptor is the entry
1553                          * address of _start and the second entry is the TOC
1554                          * value we need to use.
1555                          */
1556                         __get_user(entry, (unsigned long __user *)start);
1557                         __get_user(toc, (unsigned long __user *)start+1);
1558
1559                         /* Check whether the e_entry function descriptor entries
1560                          * need to be relocated before we can use them.
1561                          */
1562                         if (load_addr != 0) {
1563                                 entry += load_addr;
1564                                 toc   += load_addr;
1565                         }
1566                         regs->gpr[2] = toc;
1567                 }
1568                 regs->nip = entry;
1569                 regs->msr = MSR_USER64;
1570         } else {
1571                 regs->nip = start;
1572                 regs->gpr[2] = 0;
1573                 regs->msr = MSR_USER32;
1574         }
1575 #endif
1576 #ifdef CONFIG_VSX
1577         current->thread.used_vsr = 0;
1578 #endif
1579         memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
1580         current->thread.fp_save_area = NULL;
1581 #ifdef CONFIG_ALTIVEC
1582         memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
1583         current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1584         current->thread.vr_save_area = NULL;
1585         current->thread.vrsave = 0;
1586         current->thread.used_vr = 0;
1587 #endif /* CONFIG_ALTIVEC */
1588 #ifdef CONFIG_SPE
1589         memset(current->thread.evr, 0, sizeof(current->thread.evr));
1590         current->thread.acc = 0;
1591         current->thread.spefscr = 0;
1592         current->thread.used_spe = 0;
1593 #endif /* CONFIG_SPE */
1594 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1595         if (cpu_has_feature(CPU_FTR_TM))
1596                 regs->msr |= MSR_TM;
1597         current->thread.tm_tfhar = 0;
1598         current->thread.tm_texasr = 0;
1599         current->thread.tm_tfiar = 0;
1600 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1601 }
1602 EXPORT_SYMBOL(start_thread);
1603
1604 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1605                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
1606
1607 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1608 {
1609         struct pt_regs *regs = tsk->thread.regs;
1610
1611         /* This is a bit hairy.  If we are an SPE enabled  processor
1612          * (have embedded fp) we store the IEEE exception enable flags in
1613          * fpexc_mode.  fpexc_mode is also used for setting FP exception
1614          * mode (asyn, precise, disabled) for 'Classic' FP. */
1615         if (val & PR_FP_EXC_SW_ENABLE) {
1616 #ifdef CONFIG_SPE
1617                 if (cpu_has_feature(CPU_FTR_SPE)) {
1618                         /*
1619                          * When the sticky exception bits are set
1620                          * directly by userspace, it must call prctl
1621                          * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1622                          * in the existing prctl settings) or
1623                          * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1624                          * the bits being set).  <fenv.h> functions
1625                          * saving and restoring the whole
1626                          * floating-point environment need to do so
1627                          * anyway to restore the prctl settings from
1628                          * the saved environment.
1629                          */
1630                         tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1631                         tsk->thread.fpexc_mode = val &
1632                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1633                         return 0;
1634                 } else {
1635                         return -EINVAL;
1636                 }
1637 #else
1638                 return -EINVAL;
1639 #endif
1640         }
1641
1642         /* on a CONFIG_SPE this does not hurt us.  The bits that
1643          * __pack_fe01 use do not overlap with bits used for
1644          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
1645          * on CONFIG_SPE implementations are reserved so writing to
1646          * them does not change anything */
1647         if (val > PR_FP_EXC_PRECISE)
1648                 return -EINVAL;
1649         tsk->thread.fpexc_mode = __pack_fe01(val);
1650         if (regs != NULL && (regs->msr & MSR_FP) != 0)
1651                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
1652                         | tsk->thread.fpexc_mode;
1653         return 0;
1654 }
1655
1656 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1657 {
1658         unsigned int val;
1659
1660         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
1661 #ifdef CONFIG_SPE
1662                 if (cpu_has_feature(CPU_FTR_SPE)) {
1663                         /*
1664                          * When the sticky exception bits are set
1665                          * directly by userspace, it must call prctl
1666                          * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1667                          * in the existing prctl settings) or
1668                          * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1669                          * the bits being set).  <fenv.h> functions
1670                          * saving and restoring the whole
1671                          * floating-point environment need to do so
1672                          * anyway to restore the prctl settings from
1673                          * the saved environment.
1674                          */
1675                         tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1676                         val = tsk->thread.fpexc_mode;
1677                 } else
1678                         return -EINVAL;
1679 #else
1680                 return -EINVAL;
1681 #endif
1682         else
1683                 val = __unpack_fe01(tsk->thread.fpexc_mode);
1684         return put_user(val, (unsigned int __user *) adr);
1685 }
1686
1687 int set_endian(struct task_struct *tsk, unsigned int val)
1688 {
1689         struct pt_regs *regs = tsk->thread.regs;
1690
1691         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1692             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
1693                 return -EINVAL;
1694
1695         if (regs == NULL)
1696                 return -EINVAL;
1697
1698         if (val == PR_ENDIAN_BIG)
1699                 regs->msr &= ~MSR_LE;
1700         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
1701                 regs->msr |= MSR_LE;
1702         else
1703                 return -EINVAL;
1704
1705         return 0;
1706 }
1707
1708 int get_endian(struct task_struct *tsk, unsigned long adr)
1709 {
1710         struct pt_regs *regs = tsk->thread.regs;
1711         unsigned int val;
1712
1713         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
1714             !cpu_has_feature(CPU_FTR_REAL_LE))
1715                 return -EINVAL;
1716
1717         if (regs == NULL)
1718                 return -EINVAL;
1719
1720         if (regs->msr & MSR_LE) {
1721                 if (cpu_has_feature(CPU_FTR_REAL_LE))
1722                         val = PR_ENDIAN_LITTLE;
1723                 else
1724                         val = PR_ENDIAN_PPC_LITTLE;
1725         } else
1726                 val = PR_ENDIAN_BIG;
1727
1728         return put_user(val, (unsigned int __user *)adr);
1729 }
1730
1731 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
1732 {
1733         tsk->thread.align_ctl = val;
1734         return 0;
1735 }
1736
1737 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
1738 {
1739         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
1740 }
1741
1742 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
1743                                   unsigned long nbytes)
1744 {
1745         unsigned long stack_page;
1746         unsigned long cpu = task_cpu(p);
1747
1748         /*
1749          * Avoid crashing if the stack has overflowed and corrupted
1750          * task_cpu(p), which is in the thread_info struct.
1751          */
1752         if (cpu < NR_CPUS && cpu_possible(cpu)) {
1753                 stack_page = (unsigned long) hardirq_ctx[cpu];
1754                 if (sp >= stack_page + sizeof(struct thread_struct)
1755                     && sp <= stack_page + THREAD_SIZE - nbytes)
1756                         return 1;
1757
1758                 stack_page = (unsigned long) softirq_ctx[cpu];
1759                 if (sp >= stack_page + sizeof(struct thread_struct)
1760                     && sp <= stack_page + THREAD_SIZE - nbytes)
1761                         return 1;
1762         }
1763         return 0;
1764 }
1765
1766 int validate_sp(unsigned long sp, struct task_struct *p,
1767                        unsigned long nbytes)
1768 {
1769         unsigned long stack_page = (unsigned long)task_stack_page(p);
1770
1771         if (sp >= stack_page + sizeof(struct thread_struct)
1772             && sp <= stack_page + THREAD_SIZE - nbytes)
1773                 return 1;
1774
1775         return valid_irq_stack(sp, p, nbytes);
1776 }
1777
1778 EXPORT_SYMBOL(validate_sp);
1779
1780 unsigned long get_wchan(struct task_struct *p)
1781 {
1782         unsigned long ip, sp;
1783         int count = 0;
1784
1785         if (!p || p == current || p->state == TASK_RUNNING)
1786                 return 0;
1787
1788         sp = p->thread.ksp;
1789         if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1790                 return 0;
1791
1792         do {
1793                 sp = *(unsigned long *)sp;
1794                 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1795                         return 0;
1796                 if (count > 0) {
1797                         ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
1798                         if (!in_sched_functions(ip))
1799                                 return ip;
1800                 }
1801         } while (count++ < 16);
1802         return 0;
1803 }
1804
1805 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
1806
1807 void show_stack(struct task_struct *tsk, unsigned long *stack)
1808 {
1809         unsigned long sp, ip, lr, newsp;
1810         int count = 0;
1811         int firstframe = 1;
1812 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1813         int curr_frame = current->curr_ret_stack;
1814         extern void return_to_handler(void);
1815         unsigned long rth = (unsigned long)return_to_handler;
1816 #endif
1817
1818         sp = (unsigned long) stack;
1819         if (tsk == NULL)
1820                 tsk = current;
1821         if (sp == 0) {
1822                 if (tsk == current)
1823                         sp = current_stack_pointer();
1824                 else
1825                         sp = tsk->thread.ksp;
1826         }
1827
1828         lr = 0;
1829         printk("Call Trace:\n");
1830         do {
1831                 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
1832                         return;
1833
1834                 stack = (unsigned long *) sp;
1835                 newsp = stack[0];
1836                 ip = stack[STACK_FRAME_LR_SAVE];
1837                 if (!firstframe || ip != lr) {
1838                         printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
1839 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1840                         if ((ip == rth) && curr_frame >= 0) {
1841                                 printk(" (%pS)",
1842                                        (void *)current->ret_stack[curr_frame].ret);
1843                                 curr_frame--;
1844                         }
1845 #endif
1846                         if (firstframe)
1847                                 printk(" (unreliable)");
1848                         printk("\n");
1849                 }
1850                 firstframe = 0;
1851
1852                 /*
1853                  * See if this is an exception frame.
1854                  * We look for the "regshere" marker in the current frame.
1855                  */
1856                 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
1857                     && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
1858                         struct pt_regs *regs = (struct pt_regs *)
1859                                 (sp + STACK_FRAME_OVERHEAD);
1860                         lr = regs->link;
1861                         printk("--- interrupt: %lx at %pS\n    LR = %pS\n",
1862                                regs->trap, (void *)regs->nip, (void *)lr);
1863                         firstframe = 1;
1864                 }
1865
1866                 sp = newsp;
1867         } while (count++ < kstack_depth_to_print);
1868 }
1869
1870 #ifdef CONFIG_PPC64
1871 /* Called with hard IRQs off */
1872 void notrace __ppc64_runlatch_on(void)
1873 {
1874         struct thread_info *ti = current_thread_info();
1875         unsigned long ctrl;
1876
1877         ctrl = mfspr(SPRN_CTRLF);
1878         ctrl |= CTRL_RUNLATCH;
1879         mtspr(SPRN_CTRLT, ctrl);
1880
1881         ti->local_flags |= _TLF_RUNLATCH;
1882 }
1883
1884 /* Called with hard IRQs off */
1885 void notrace __ppc64_runlatch_off(void)
1886 {
1887         struct thread_info *ti = current_thread_info();
1888         unsigned long ctrl;
1889
1890         ti->local_flags &= ~_TLF_RUNLATCH;
1891
1892         ctrl = mfspr(SPRN_CTRLF);
1893         ctrl &= ~CTRL_RUNLATCH;
1894         mtspr(SPRN_CTRLT, ctrl);
1895 }
1896 #endif /* CONFIG_PPC64 */
1897
1898 unsigned long arch_align_stack(unsigned long sp)
1899 {
1900         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1901                 sp -= get_random_int() & ~PAGE_MASK;
1902         return sp & ~0xf;
1903 }
1904
1905 static inline unsigned long brk_rnd(void)
1906 {
1907         unsigned long rnd = 0;
1908
1909         /* 8MB for 32bit, 1GB for 64bit */
1910         if (is_32bit_task())
1911                 rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
1912         else
1913                 rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
1914
1915         return rnd << PAGE_SHIFT;
1916 }
1917
1918 unsigned long arch_randomize_brk(struct mm_struct *mm)
1919 {
1920         unsigned long base = mm->brk;
1921         unsigned long ret;
1922
1923 #ifdef CONFIG_PPC_STD_MMU_64
1924         /*
1925          * If we are using 1TB segments and we are allowed to randomise
1926          * the heap, we can put it above 1TB so it is backed by a 1TB
1927          * segment. Otherwise the heap will be in the bottom 1TB
1928          * which always uses 256MB segments and this may result in a
1929          * performance penalty.
1930          */
1931         if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
1932                 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
1933 #endif
1934
1935         ret = PAGE_ALIGN(base + brk_rnd());
1936
1937         if (ret < mm->brk)
1938                 return mm->brk;
1939
1940         return ret;
1941 }
1942