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/init.h>
  29 #include <linux/prctl.h>
  30 #include <linux/init_task.h>
  31 #include <linux/module.h>
  32 #include <linux/kallsyms.h>
  33 #include <linux/mqueue.h>
  34 #include <linux/hardirq.h>
  35 #include <linux/utsname.h>
  36
  37 #include <asm/pgtable.h>
  38 #include <asm/uaccess.h>
  39 #include <asm/system.h>
  40 #include <asm/io.h>
  41 #include <asm/processor.h>
  42 #include <asm/mmu.h>
  43 #include <asm/prom.h>
  44 #include <asm/machdep.h>
  45 #include <asm/time.h>
  46 #include <asm/syscalls.h>
  47 #ifdef CONFIG_PPC64
  48 #include <asm/firmware.h>
  49 #endif
  50
  51 extern unsigned long _get_SP(void);
  52
  53 #ifndef CONFIG_SMP
  54 struct task_struct *last_task_used_math = NULL;
  55 struct task_struct *last_task_used_altivec = NULL;
  56 struct task_struct *last_task_used_spe = NULL;
  57 #endif
  58
  59 /*
  60  * Make sure the floating-point register state in the
  61  * the thread_struct is up to date for task tsk.
  62  */
  63 void flush_fp_to_thread(struct task_struct *tsk)
  64 {
  65         if (tsk->thread.regs) {
  66                 /*
  67                  * We need to disable preemption here because if we didn't,
  68                  * another process could get scheduled after the regs->msr
  69                  * test but before we have finished saving the FP registers
  70                  * to the thread_struct.  That process could take over the
  71                  * FPU, and then when we get scheduled again we would store
  72                  * bogus values for the remaining FP registers.
  73                  */
  74                 preempt_disable();
  75                 if (tsk->thread.regs->msr & MSR_FP) {
  76 #ifdef CONFIG_SMP
  77                         /*
  78                          * This should only ever be called for current or
  79                          * for a stopped child process.  Since we save away
  80                          * the FP register state on context switch on SMP,
  81                          * there is something wrong if a stopped child appears
  82                          * to still have its FP state in the CPU registers.
  83                          */
  84                         BUG_ON(tsk != current);
  85 #endif
  86                         giveup_fpu(tsk);
  87                 }
  88                 preempt_enable();
  89         }
  90 }
  91
  92 void enable_kernel_fp(void)
  93 {
  94         WARN_ON(preemptible());
  95
  96 #ifdef CONFIG_SMP
  97         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
  98                 giveup_fpu(current);
  99         else
 100                 giveup_fpu(NULL);       /* just enables FP for kernel */
 101 #else
 102         giveup_fpu(last_task_used_math);
 103 #endif /* CONFIG_SMP */
 104 }
 105 EXPORT_SYMBOL(enable_kernel_fp);
 106
 107 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
 108 {
 109         if (!tsk->thread.regs)
 110                 return 0;
 111         flush_fp_to_thread(current);
 112
 113         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
 114
 115         return 1;
 116 }
 117
 118 #ifdef CONFIG_ALTIVEC
 119 void enable_kernel_altivec(void)
 120 {
 121         WARN_ON(preemptible());
 122
 123 #ifdef CONFIG_SMP
 124         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
 125                 giveup_altivec(current);
 126         else
 127                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
 128 #else
 129         giveup_altivec(last_task_used_altivec);
 130 #endif /* CONFIG_SMP */
 131 }
 132 EXPORT_SYMBOL(enable_kernel_altivec);
 133
 134 /*
 135  * Make sure the VMX/Altivec register state in the
 136  * the thread_struct is up to date for task tsk.
 137  */
 138 void flush_altivec_to_thread(struct task_struct *tsk)
 139 {
 140         if (tsk->thread.regs) {
 141                 preempt_disable();
 142                 if (tsk->thread.regs->msr & MSR_VEC) {
 143 #ifdef CONFIG_SMP
 144                         BUG_ON(tsk != current);
 145 #endif
 146                         giveup_altivec(tsk);
 147                 }
 148                 preempt_enable();
 149         }
 150 }
 151
 152 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
 153 {
 154         flush_altivec_to_thread(current);
 155         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
 156         return 1;
 157 }
 158 #endif /* CONFIG_ALTIVEC */
 159
 160 #ifdef CONFIG_SPE
 161
 162 void enable_kernel_spe(void)
 163 {
 164         WARN_ON(preemptible());
 165
 166 #ifdef CONFIG_SMP
 167         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
 168                 giveup_spe(current);
 169         else
 170                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
 171 #else
 172         giveup_spe(last_task_used_spe);
 173 #endif /* __SMP __ */
 174 }
 175 EXPORT_SYMBOL(enable_kernel_spe);
 176
 177 void flush_spe_to_thread(struct task_struct *tsk)
 178 {
 179         if (tsk->thread.regs) {
 180                 preempt_disable();
 181                 if (tsk->thread.regs->msr & MSR_SPE) {
 182 #ifdef CONFIG_SMP
 183                         BUG_ON(tsk != current);
 184 #endif
 185                         giveup_spe(tsk);
 186                 }
 187                 preempt_enable();
 188         }
 189 }
 190
 191 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
 192 {
 193         flush_spe_to_thread(current);
 194         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
 195         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
 196         return 1;
 197 }
 198 #endif /* CONFIG_SPE */
 199
 200 #ifndef CONFIG_SMP
 201 /*
 202  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
 203  * and the current task has some state, discard it.
 204  */
 205 void discard_lazy_cpu_state(void)
 206 {
 207         preempt_disable();
 208         if (last_task_used_math == current)
 209                 last_task_used_math = NULL;
 210 #ifdef CONFIG_ALTIVEC
 211         if (last_task_used_altivec == current)
 212                 last_task_used_altivec = NULL;
 213 #endif /* CONFIG_ALTIVEC */
 214 #ifdef CONFIG_SPE
 215         if (last_task_used_spe == current)
 216                 last_task_used_spe = NULL;
 217 #endif
 218         preempt_enable();
 219 }
 220 #endif /* CONFIG_SMP */
 221
 222 int set_dabr(unsigned long dabr)
 223 {
 224 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
 225         if (ppc_md.set_dabr)
 226                 return ppc_md.set_dabr(dabr);
 227 #endif
 228
 229         /* XXX should we have a CPU_FTR_HAS_DABR ? */
 230 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx)
 231         mtspr(SPRN_DABR, dabr);
 232 #endif
 233         return 0;
 234 }
 235
 236 #ifdef CONFIG_PPC64
 237 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
 238 #endif
 239
 240 static DEFINE_PER_CPU(unsigned long, current_dabr);
 241
 242 struct task_struct *__switch_to(struct task_struct *prev,
 243         struct task_struct *new)
 244 {
 245         struct thread_struct *new_thread, *old_thread;
 246         unsigned long flags;
 247         struct task_struct *last;
 248
 249 #ifdef CONFIG_SMP
 250         /* avoid complexity of lazy save/restore of fpu
 251          * by just saving it every time we switch out if
 252          * this task used the fpu during the last quantum.
 253          *
 254          * If it tries to use the fpu again, it'll trap and
 255          * reload its fp regs.  So we don't have to do a restore
 256          * every switch, just a save.
 257          *  -- Cort
 258          */
 259         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
 260                 giveup_fpu(prev);
 261 #ifdef CONFIG_ALTIVEC
 262         /*
 263          * If the previous thread used altivec in the last quantum
 264          * (thus changing altivec regs) then save them.
 265          * We used to check the VRSAVE register but not all apps
 266          * set it, so we don't rely on it now (and in fact we need
 267          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
 268          *
 269          * On SMP we always save/restore altivec regs just to avoid the
 270          * complexity of changing processors.
 271          *  -- Cort
 272          */
 273         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
 274                 giveup_altivec(prev);
 275 #endif /* CONFIG_ALTIVEC */
 276 #ifdef CONFIG_SPE
 277         /*
 278          * If the previous thread used spe in the last quantum
 279          * (thus changing spe regs) then save them.
 280          *
 281          * On SMP we always save/restore spe regs just to avoid the
 282          * complexity of changing processors.
 283          */
 284         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
 285                 giveup_spe(prev);
 286 #endif /* CONFIG_SPE */
 287
 288 #else  /* CONFIG_SMP */
 289 #ifdef CONFIG_ALTIVEC
 290         /* Avoid the trap.  On smp this this never happens since
 291          * we don't set last_task_used_altivec -- Cort
 292          */
 293         if (new->thread.regs && last_task_used_altivec == new)
 294                 new->thread.regs->msr |= MSR_VEC;
 295 #endif /* CONFIG_ALTIVEC */
 296 #ifdef CONFIG_SPE
 297         /* Avoid the trap.  On smp this this never happens since
 298          * we don't set last_task_used_spe
 299          */
 300         if (new->thread.regs && last_task_used_spe == new)
 301                 new->thread.regs->msr |= MSR_SPE;
 302 #endif /* CONFIG_SPE */
 303
 304 #endif /* CONFIG_SMP */
 305
 306         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
 307                 set_dabr(new->thread.dabr);
 308                 __get_cpu_var(current_dabr) = new->thread.dabr;
 309         }
 310
 311         new_thread = &new->thread;
 312         old_thread = &current->thread;
 313
 314 #ifdef CONFIG_PPC64
 315         /*
 316          * Collect processor utilization data per process
 317          */
 318         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
 319                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
 320                 long unsigned start_tb, current_tb;
 321                 start_tb = old_thread->start_tb;
 322                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
 323                 old_thread->accum_tb += (current_tb - start_tb);
 324                 new_thread->start_tb = current_tb;
 325         }
 326 #endif
 327
 328         local_irq_save(flags);
 329
 330         account_system_vtime(current);
 331         account_process_vtime(current);
 332         calculate_steal_time();
 333
 334         last = _switch(old_thread, new_thread);
 335
 336         local_irq_restore(flags);
 337
 338         return last;
 339 }
 340
 341 static int instructions_to_print = 16;
 342
 343 static void show_instructions(struct pt_regs *regs)
 344 {
 345         int i;
 346         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
 347                         sizeof(int));
 348
 349         printk("Instruction dump:");
 350
 351         for (i = 0; i < instructions_to_print; i++) {
 352                 int instr;
 353
 354                 if (!(i % 8))
 355                         printk("\n");
 356
 357 #if !defined(CONFIG_BOOKE)
 358                 /* If executing with the IMMU off, adjust pc rather
 359                  * than print XXXXXXXX.
 360                  */
 361                 if (!(regs->msr & MSR_IR))
 362                         pc = (unsigned long)phys_to_virt(pc);
 363 #endif
 364
 365                 /* We use __get_user here *only* to avoid an OOPS on a
 366                  * bad address because the pc *should* only be a
 367                  * kernel address.
 368                  */
 369                 if (!__kernel_text_address(pc) ||
 370                      __get_user(instr, (unsigned int __user *)pc)) {
 371                         printk("XXXXXXXX ");
 372                 } else {
 373                         if (regs->nip == pc)
 374                                 printk("<%08x> ", instr);
 375                         else
 376                                 printk("%08x ", instr);
 377                 }
 378
 379                 pc += sizeof(int);
 380         }
 381
 382         printk("\n");
 383 }
 384
 385 static struct regbit {
 386         unsigned long bit;
 387         const char *name;
 388 } msr_bits[] = {
 389         {MSR_EE,        "EE"},
 390         {MSR_PR,        "PR"},
 391         {MSR_FP,        "FP"},
 392         {MSR_ME,        "ME"},
 393         {MSR_IR,        "IR"},
 394         {MSR_DR,        "DR"},
 395         {0,             NULL}
 396 };
 397
 398 static void printbits(unsigned long val, struct regbit *bits)
 399 {
 400         const char *sep = "";
 401
 402         printk("<");
 403         for (; bits->bit; ++bits)
 404                 if (val & bits->bit) {
 405                         printk("%s%s", sep, bits->name);
 406                         sep = ",";
 407                 }
 408         printk(">");
 409 }
 410
 411 #ifdef CONFIG_PPC64
 412 #define REG             "%016lx"
 413 #define REGS_PER_LINE   4
 414 #define LAST_VOLATILE   13
 415 #else
 416 #define REG             "%08lx"
 417 #define REGS_PER_LINE   8
 418 #define LAST_VOLATILE   12
 419 #endif
 420
 421 void show_regs(struct pt_regs * regs)
 422 {
 423         int i, trap;
 424
 425         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
 426                regs->nip, regs->link, regs->ctr);
 427         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
 428                regs, regs->trap, print_tainted(), init_utsname()->release);
 429         printk("MSR: "REG" ", regs->msr);
 430         printbits(regs->msr, msr_bits);
 431         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
 432         trap = TRAP(regs);
 433         if (trap == 0x300 || trap == 0x600)
 434 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
 435                 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
 436 #else
 437                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
 438 #endif
 439         printk("TASK = %p[%d] '%s' THREAD: %p",
 440                current, current->pid, current->comm, task_thread_info(current));
 441
 442 #ifdef CONFIG_SMP
 443         printk(" CPU: %d", smp_processor_id());
 444 #endif /* CONFIG_SMP */
 445
 446         for (i = 0;  i < 32;  i++) {
 447                 if ((i % REGS_PER_LINE) == 0)
 448                         printk("\n" KERN_INFO "GPR%02d: ", i);
 449                 printk(REG " ", regs->gpr[i]);
 450                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
 451                         break;
 452         }
 453         printk("\n");
 454 #ifdef CONFIG_KALLSYMS
 455         /*
 456          * Lookup NIP late so we have the best change of getting the
 457          * above info out without failing
 458          */
 459         printk("NIP ["REG"] ", regs->nip);
 460         print_symbol("%s\n", regs->nip);
 461         printk("LR ["REG"] ", regs->link);
 462         print_symbol("%s\n", regs->link);
 463 #endif
 464         show_stack(current, (unsigned long *) regs->gpr[1]);
 465         if (!user_mode(regs))
 466                 show_instructions(regs);
 467 }
 468
 469 void exit_thread(void)
 470 {
 471         discard_lazy_cpu_state();
 472 }
 473
 474 void flush_thread(void)
 475 {
 476 #ifdef CONFIG_PPC64
 477         struct thread_info *t = current_thread_info();
 478
 479         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 480                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 481                 if (test_ti_thread_flag(t, TIF_32BIT))
 482                         clear_ti_thread_flag(t, TIF_32BIT);
 483                 else
 484                         set_ti_thread_flag(t, TIF_32BIT);
 485         }
 486 #endif
 487
 488         discard_lazy_cpu_state();
 489
 490         if (current->thread.dabr) {
 491                 current->thread.dabr = 0;
 492                 set_dabr(0);
 493         }
 494 }
 495
 496 void
 497 release_thread(struct task_struct *t)
 498 {
 499 }
 500
 501 /*
 502  * This gets called before we allocate a new thread and copy
 503  * the current task into it.
 504  */
 505 void prepare_to_copy(struct task_struct *tsk)
 506 {
 507         flush_fp_to_thread(current);
 508         flush_altivec_to_thread(current);
 509         flush_spe_to_thread(current);
 510 }
 511
 512 /*
 513  * Copy a thread..
 514  */
 515 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
 516                 unsigned long unused, struct task_struct *p,
 517                 struct pt_regs *regs)
 518 {
 519         struct pt_regs *childregs, *kregs;
 520         extern void ret_from_fork(void);
 521         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
 522
 523         CHECK_FULL_REGS(regs);
 524         /* Copy registers */
 525         sp -= sizeof(struct pt_regs);
 526         childregs = (struct pt_regs *) sp;
 527         *childregs = *regs;
 528         if ((childregs->msr & MSR_PR) == 0) {
 529                 /* for kernel thread, set `current' and stackptr in new task */
 530                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
 531 #ifdef CONFIG_PPC32
 532                 childregs->gpr[2] = (unsigned long) p;
 533 #else
 534                 clear_tsk_thread_flag(p, TIF_32BIT);
 535 #endif
 536                 p->thread.regs = NULL;  /* no user register state */
 537         } else {
 538                 childregs->gpr[1] = usp;
 539                 p->thread.regs = childregs;
 540                 if (clone_flags & CLONE_SETTLS) {
 541 #ifdef CONFIG_PPC64
 542                         if (!test_thread_flag(TIF_32BIT))
 543                                 childregs->gpr[13] = childregs->gpr[6];
 544                         else
 545 #endif
 546                                 childregs->gpr[2] = childregs->gpr[6];
 547                 }
 548         }
 549         childregs->gpr[3] = 0;  /* Result from fork() */
 550         sp -= STACK_FRAME_OVERHEAD;
 551
 552         /*
 553          * The way this works is that at some point in the future
 554          * some task will call _switch to switch to the new task.
 555          * That will pop off the stack frame created below and start
 556          * the new task running at ret_from_fork.  The new task will
 557          * do some house keeping and then return from the fork or clone
 558          * system call, using the stack frame created above.
 559          */
 560         sp -= sizeof(struct pt_regs);
 561         kregs = (struct pt_regs *) sp;
 562         sp -= STACK_FRAME_OVERHEAD;
 563         p->thread.ksp = sp;
 564
 565 #ifdef CONFIG_PPC64
 566         if (cpu_has_feature(CPU_FTR_SLB)) {
 567                 unsigned long sp_vsid = get_kernel_vsid(sp);
 568                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
 569
 570                 sp_vsid <<= SLB_VSID_SHIFT;
 571                 sp_vsid |= SLB_VSID_KERNEL | llp;
 572                 p->thread.ksp_vsid = sp_vsid;
 573         }
 574
 575         /*
 576          * The PPC64 ABI makes use of a TOC to contain function
 577          * pointers.  The function (ret_from_except) is actually a pointer
 578          * to the TOC entry.  The first entry is a pointer to the actual
 579          * function.
 580          */
 581         kregs->nip = *((unsigned long *)ret_from_fork);
 582 #else
 583         kregs->nip = (unsigned long)ret_from_fork;
 584 #endif
 585
 586         return 0;
 587 }
 588
 589 /*
 590  * Set up a thread for executing a new program
 591  */
 592 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 593 {
 594 #ifdef CONFIG_PPC64
 595         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
 596 #endif
 597
 598         set_fs(USER_DS);
 599
 600         /*
 601          * If we exec out of a kernel thread then thread.regs will not be
 602          * set.  Do it now.
 603          */
 604         if (!current->thread.regs) {
 605                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
 606                 current->thread.regs = regs - 1;
 607         }
 608
 609         memset(regs->gpr, 0, sizeof(regs->gpr));
 610         regs->ctr = 0;
 611         regs->link = 0;
 612         regs->xer = 0;
 613         regs->ccr = 0;
 614         regs->gpr[1] = sp;
 615
 616         /*
 617          * We have just cleared all the nonvolatile GPRs, so make
 618          * FULL_REGS(regs) return true.  This is necessary to allow
 619          * ptrace to examine the thread immediately after exec.
 620          */
 621         regs->trap &= ~1UL;
 622
 623 #ifdef CONFIG_PPC32
 624         regs->mq = 0;
 625         regs->nip = start;
 626         regs->msr = MSR_USER;
 627 #else
 628         if (!test_thread_flag(TIF_32BIT)) {
 629                 unsigned long entry, toc;
 630
 631                 /* start is a relocated pointer to the function descriptor for
 632                  * the elf _start routine.  The first entry in the function
 633                  * descriptor is the entry address of _start and the second
 634                  * entry is the TOC value we need to use.
 635                  */
 636                 __get_user(entry, (unsigned long __user *)start);
 637                 __get_user(toc, (unsigned long __user *)start+1);
 638
 639                 /* Check whether the e_entry function descriptor entries
 640                  * need to be relocated before we can use them.
 641                  */
 642                 if (load_addr != 0) {
 643                         entry += load_addr;
 644                         toc   += load_addr;
 645                 }
 646                 regs->nip = entry;
 647                 regs->gpr[2] = toc;
 648                 regs->msr = MSR_USER64;
 649         } else {
 650                 regs->nip = start;
 651                 regs->gpr[2] = 0;
 652                 regs->msr = MSR_USER32;
 653         }
 654 #endif
 655
 656         discard_lazy_cpu_state();
 657         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
 658         current->thread.fpscr.val = 0;
 659 #ifdef CONFIG_ALTIVEC
 660         memset(current->thread.vr, 0, sizeof(current->thread.vr));
 661         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
 662         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
 663         current->thread.vrsave = 0;
 664         current->thread.used_vr = 0;
 665 #endif /* CONFIG_ALTIVEC */
 666 #ifdef CONFIG_SPE
 667         memset(current->thread.evr, 0, sizeof(current->thread.evr));
 668         current->thread.acc = 0;
 669         current->thread.spefscr = 0;
 670         current->thread.used_spe = 0;
 671 #endif /* CONFIG_SPE */
 672 }
 673
 674 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
 675                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
 676
 677 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
 678 {
 679         struct pt_regs *regs = tsk->thread.regs;
 680
 681         /* This is a bit hairy.  If we are an SPE enabled  processor
 682          * (have embedded fp) we store the IEEE exception enable flags in
 683          * fpexc_mode.  fpexc_mode is also used for setting FP exception
 684          * mode (asyn, precise, disabled) for 'Classic' FP. */
 685         if (val & PR_FP_EXC_SW_ENABLE) {
 686 #ifdef CONFIG_SPE
 687                 if (cpu_has_feature(CPU_FTR_SPE)) {
 688                         tsk->thread.fpexc_mode = val &
 689                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
 690                         return 0;
 691                 } else {
 692                         return -EINVAL;
 693                 }
 694 #else
 695                 return -EINVAL;
 696 #endif
 697         }
 698
 699         /* on a CONFIG_SPE this does not hurt us.  The bits that
 700          * __pack_fe01 use do not overlap with bits used for
 701          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
 702          * on CONFIG_SPE implementations are reserved so writing to
 703          * them does not change anything */
 704         if (val > PR_FP_EXC_PRECISE)
 705                 return -EINVAL;
 706         tsk->thread.fpexc_mode = __pack_fe01(val);
 707         if (regs != NULL && (regs->msr & MSR_FP) != 0)
 708                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
 709                         | tsk->thread.fpexc_mode;
 710         return 0;
 711 }
 712
 713 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
 714 {
 715         unsigned int val;
 716
 717         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
 718 #ifdef CONFIG_SPE
 719                 if (cpu_has_feature(CPU_FTR_SPE))
 720                         val = tsk->thread.fpexc_mode;
 721                 else
 722                         return -EINVAL;
 723 #else
 724                 return -EINVAL;
 725 #endif
 726         else
 727                 val = __unpack_fe01(tsk->thread.fpexc_mode);
 728         return put_user(val, (unsigned int __user *) adr);
 729 }
 730
 731 int set_endian(struct task_struct *tsk, unsigned int val)
 732 {
 733         struct pt_regs *regs = tsk->thread.regs;
 734
 735         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
 736             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
 737                 return -EINVAL;
 738
 739         if (regs == NULL)
 740                 return -EINVAL;
 741
 742         if (val == PR_ENDIAN_BIG)
 743                 regs->msr &= ~MSR_LE;
 744         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
 745                 regs->msr |= MSR_LE;
 746         else
 747                 return -EINVAL;
 748
 749         return 0;
 750 }
 751
 752 int get_endian(struct task_struct *tsk, unsigned long adr)
 753 {
 754         struct pt_regs *regs = tsk->thread.regs;
 755         unsigned int val;
 756
 757         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
 758             !cpu_has_feature(CPU_FTR_REAL_LE))
 759                 return -EINVAL;
 760
 761         if (regs == NULL)
 762                 return -EINVAL;
 763
 764         if (regs->msr & MSR_LE) {
 765                 if (cpu_has_feature(CPU_FTR_REAL_LE))
 766                         val = PR_ENDIAN_LITTLE;
 767                 else
 768                         val = PR_ENDIAN_PPC_LITTLE;
 769         } else
 770                 val = PR_ENDIAN_BIG;
 771
 772         return put_user(val, (unsigned int __user *)adr);
 773 }
 774
 775 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
 776 {
 777         tsk->thread.align_ctl = val;
 778         return 0;
 779 }
 780
 781 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
 782 {
 783         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
 784 }
 785
 786 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
 787
 788 int sys_clone(unsigned long clone_flags, unsigned long usp,
 789               int __user *parent_tidp, void __user *child_threadptr,
 790               int __user *child_tidp, int p6,
 791               struct pt_regs *regs)
 792 {
 793         CHECK_FULL_REGS(regs);
 794         if (usp == 0)
 795                 usp = regs->gpr[1];     /* stack pointer for child */
 796 #ifdef CONFIG_PPC64
 797         if (test_thread_flag(TIF_32BIT)) {
 798                 parent_tidp = TRUNC_PTR(parent_tidp);
 799                 child_tidp = TRUNC_PTR(child_tidp);
 800         }
 801 #endif
 802         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
 803 }
 804
 805 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
 806              unsigned long p4, unsigned long p5, unsigned long p6,
 807              struct pt_regs *regs)
 808 {
 809         CHECK_FULL_REGS(regs);
 810         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
 811 }
 812
 813 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
 814               unsigned long p4, unsigned long p5, unsigned long p6,
 815               struct pt_regs *regs)
 816 {
 817         CHECK_FULL_REGS(regs);
 818         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
 819                         regs, 0, NULL, NULL);
 820 }
 821
 822 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
 823                unsigned long a3, unsigned long a4, unsigned long a5,
 824                struct pt_regs *regs)
 825 {
 826         int error;
 827         char *filename;
 828
 829         filename = getname((char __user *) a0);
 830         error = PTR_ERR(filename);
 831         if (IS_ERR(filename))
 832                 goto out;
 833         flush_fp_to_thread(current);
 834         flush_altivec_to_thread(current);
 835         flush_spe_to_thread(current);
 836         error = do_execve(filename, (char __user * __user *) a1,
 837                           (char __user * __user *) a2, regs);
 838         if (error == 0) {
 839                 task_lock(current);
 840                 current->ptrace &= ~PT_DTRACE;
 841                 task_unlock(current);
 842         }
 843         putname(filename);
 844 out:
 845         return error;
 846 }
 847
 848 #ifdef CONFIG_IRQSTACKS
 849 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
 850                                   unsigned long nbytes)
 851 {
 852         unsigned long stack_page;
 853         unsigned long cpu = task_cpu(p);
 854
 855         /*
 856          * Avoid crashing if the stack has overflowed and corrupted
 857          * task_cpu(p), which is in the thread_info struct.
 858          */
 859         if (cpu < NR_CPUS && cpu_possible(cpu)) {
 860                 stack_page = (unsigned long) hardirq_ctx[cpu];
 861                 if (sp >= stack_page + sizeof(struct thread_struct)
 862                     && sp <= stack_page + THREAD_SIZE - nbytes)
 863                         return 1;
 864
 865                 stack_page = (unsigned long) softirq_ctx[cpu];
 866                 if (sp >= stack_page + sizeof(struct thread_struct)
 867                     && sp <= stack_page + THREAD_SIZE - nbytes)
 868                         return 1;
 869         }
 870         return 0;
 871 }
 872
 873 #else
 874 #define valid_irq_stack(sp, p, nb)      0
 875 #endif /* CONFIG_IRQSTACKS */
 876
 877 int validate_sp(unsigned long sp, struct task_struct *p,
 878                        unsigned long nbytes)
 879 {
 880         unsigned long stack_page = (unsigned long)task_stack_page(p);
 881
 882         if (sp >= stack_page + sizeof(struct thread_struct)
 883             && sp <= stack_page + THREAD_SIZE - nbytes)
 884                 return 1;
 885
 886         return valid_irq_stack(sp, p, nbytes);
 887 }
 888
 889 #ifdef CONFIG_PPC64
 890 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
 891 #define FRAME_LR_SAVE   2
 892 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
 893 #define REGS_MARKER     0x7265677368657265ul
 894 #define FRAME_MARKER    12
 895 #else
 896 #define MIN_STACK_FRAME 16
 897 #define FRAME_LR_SAVE   1
 898 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
 899 #define REGS_MARKER     0x72656773ul
 900 #define FRAME_MARKER    2
 901 #endif
 902
 903 EXPORT_SYMBOL(validate_sp);
 904
 905 unsigned long get_wchan(struct task_struct *p)
 906 {
 907         unsigned long ip, sp;
 908         int count = 0;
 909
 910         if (!p || p == current || p->state == TASK_RUNNING)
 911                 return 0;
 912
 913         sp = p->thread.ksp;
 914         if (!validate_sp(sp, p, MIN_STACK_FRAME))
 915                 return 0;
 916
 917         do {
 918                 sp = *(unsigned long *)sp;
 919                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
 920                         return 0;
 921                 if (count > 0) {
 922                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
 923                         if (!in_sched_functions(ip))
 924                                 return ip;
 925                 }
 926         } while (count++ < 16);
 927         return 0;
 928 }
 929
 930 static int kstack_depth_to_print = 64;
 931
 932 void show_stack(struct task_struct *tsk, unsigned long *stack)
 933 {
 934         unsigned long sp, ip, lr, newsp;
 935         int count = 0;
 936         int firstframe = 1;
 937
 938         sp = (unsigned long) stack;
 939         if (tsk == NULL)
 940                 tsk = current;
 941         if (sp == 0) {
 942                 if (tsk == current)
 943                         asm("mr %0,1" : "=r" (sp));
 944                 else
 945                         sp = tsk->thread.ksp;
 946         }
 947
 948         lr = 0;
 949         printk("Call Trace:\n");
 950         do {
 951                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
 952                         return;
 953
 954                 stack = (unsigned long *) sp;
 955                 newsp = stack[0];
 956                 ip = stack[FRAME_LR_SAVE];
 957                 if (!firstframe || ip != lr) {
 958                         printk("["REG"] ["REG"] ", sp, ip);
 959                         print_symbol("%s", ip);
 960                         if (firstframe)
 961                                 printk(" (unreliable)");
 962                         printk("\n");
 963                 }
 964                 firstframe = 0;
 965
 966                 /*
 967                  * See if this is an exception frame.
 968                  * We look for the "regshere" marker in the current frame.
 969                  */
 970                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
 971                     && stack[FRAME_MARKER] == REGS_MARKER) {
 972                         struct pt_regs *regs = (struct pt_regs *)
 973                                 (sp + STACK_FRAME_OVERHEAD);
 974                         printk("--- Exception: %lx", regs->trap);
 975                         print_symbol(" at %s\n", regs->nip);
 976                         lr = regs->link;
 977                         print_symbol("    LR = %s\n", lr);
 978                         firstframe = 1;
 979                 }
 980
 981                 sp = newsp;
 982         } while (count++ < kstack_depth_to_print);
 983 }
 984
 985 void dump_stack(void)
 986 {
 987         show_stack(current, NULL);
 988 }
 989 EXPORT_SYMBOL(dump_stack);
 990
 991 #ifdef CONFIG_PPC64
 992 void ppc64_runlatch_on(void)
 993 {
 994         unsigned long ctrl;
 995
 996         if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
 997                 HMT_medium();
 998
 999                 ctrl = mfspr(SPRN_CTRLF);
1000                 ctrl |= CTRL_RUNLATCH;
1001                 mtspr(SPRN_CTRLT, ctrl);
1002
1003                 set_thread_flag(TIF_RUNLATCH);
1004         }
1005 }
1006
1007 void ppc64_runlatch_off(void)
1008 {
1009         unsigned long ctrl;
1010
1011         if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
1012                 HMT_medium();
1013
1014                 clear_thread_flag(TIF_RUNLATCH);
1015
1016                 ctrl = mfspr(SPRN_CTRLF);
1017                 ctrl &= ~CTRL_RUNLATCH;
1018                 mtspr(SPRN_CTRLT, ctrl);
1019         }
1020 }
1021 #endif