arch/sparc/kernel/process_64.c

   1 /*  arch/sparc64/kernel/process.c
   2  *
   3  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
   4  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   5  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   6  */
   7
   8 /*
   9  * This file handles the architecture-dependent parts of process handling..
  10  */
  11
  12 #include <stdarg.h>
  13
  14 #include <linux/errno.h>
  15 #include <linux/export.h>
  16 #include <linux/sched.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mm.h>
  19 #include <linux/fs.h>
  20 #include <linux/smp.h>
  21 #include <linux/stddef.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/slab.h>
  24 #include <linux/user.h>
  25 #include <linux/delay.h>
  26 #include <linux/compat.h>
  27 #include <linux/tick.h>
  28 #include <linux/init.h>
  29 #include <linux/cpu.h>
  30 #include <linux/perf_event.h>
  31 #include <linux/elfcore.h>
  32 #include <linux/sysrq.h>
  33 #include <linux/nmi.h>
  34
  35 #include <asm/uaccess.h>
  36 #include <asm/page.h>
  37 #include <asm/pgalloc.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/processor.h>
  40 #include <asm/pstate.h>
  41 #include <asm/elf.h>
  42 #include <asm/fpumacro.h>
  43 #include <asm/head.h>
  44 #include <asm/cpudata.h>
  45 #include <asm/mmu_context.h>
  46 #include <asm/unistd.h>
  47 #include <asm/hypervisor.h>
  48 #include <asm/syscalls.h>
  49 #include <asm/irq_regs.h>
  50 #include <asm/smp.h>
  51 #include <asm/pcr.h>
  52
  53 #include "kstack.h"
  54
  55 static void sparc64_yield(int cpu)
  56 {
  57         if (tlb_type != hypervisor) {
  58                 touch_nmi_watchdog();
  59                 return;
  60         }
  61
  62         clear_thread_flag(TIF_POLLING_NRFLAG);
  63         smp_mb__after_clear_bit();
  64
  65         while (!need_resched() && !cpu_is_offline(cpu)) {
  66                 unsigned long pstate;
  67
  68                 /* Disable interrupts. */
  69                 __asm__ __volatile__(
  70                         "rdpr %%pstate, %0\n\t"
  71                         "andn %0, %1, %0\n\t"
  72                         "wrpr %0, %%g0, %%pstate"
  73                         : "=&r" (pstate)
  74                         : "i" (PSTATE_IE));
  75
  76                 if (!need_resched() && !cpu_is_offline(cpu))
  77                         sun4v_cpu_yield();
  78
  79                 /* Re-enable interrupts. */
  80                 __asm__ __volatile__(
  81                         "rdpr %%pstate, %0\n\t"
  82                         "or %0, %1, %0\n\t"
  83                         "wrpr %0, %%g0, %%pstate"
  84                         : "=&r" (pstate)
  85                         : "i" (PSTATE_IE));
  86         }
  87
  88         set_thread_flag(TIF_POLLING_NRFLAG);
  89 }
  90
  91 /* The idle loop on sparc64. */
  92 void cpu_idle(void)
  93 {
  94         int cpu = smp_processor_id();
  95
  96         set_thread_flag(TIF_POLLING_NRFLAG);
  97
  98         while(1) {
  99                 tick_nohz_idle_enter();
 100                 rcu_idle_enter();
 101
 102                 while (!need_resched() && !cpu_is_offline(cpu))
 103                         sparc64_yield(cpu);
 104
 105                 rcu_idle_exit();
 106                 tick_nohz_idle_exit();
 107
 108 #ifdef CONFIG_HOTPLUG_CPU
 109                 if (cpu_is_offline(cpu)) {
 110                         sched_preempt_enable_no_resched();
 111                         cpu_play_dead();
 112                 }
 113 #endif
 114                 schedule_preempt_disabled();
 115         }
 116 }
 117
 118 #ifdef CONFIG_COMPAT
 119 static void show_regwindow32(struct pt_regs *regs)
 120 {
 121         struct reg_window32 __user *rw;
 122         struct reg_window32 r_w;
 123         mm_segment_t old_fs;
 124
 125         __asm__ __volatile__ ("flushw");
 126         rw = compat_ptr((unsigned)regs->u_regs[14]);
 127         old_fs = get_fs();
 128         set_fs (USER_DS);
 129         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 130                 set_fs (old_fs);
 131                 return;
 132         }
 133
 134         set_fs (old_fs);
 135         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 136                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 137                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 138                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 139         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 140                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 141                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 142                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 143 }
 144 #else
 145 #define show_regwindow32(regs)  do { } while (0)
 146 #endif
 147
 148 static void show_regwindow(struct pt_regs *regs)
 149 {
 150         struct reg_window __user *rw;
 151         struct reg_window *rwk;
 152         struct reg_window r_w;
 153         mm_segment_t old_fs;
 154
 155         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 156                 __asm__ __volatile__ ("flushw");
 157                 rw = (struct reg_window __user *)
 158                         (regs->u_regs[14] + STACK_BIAS);
 159                 rwk = (struct reg_window *)
 160                         (regs->u_regs[14] + STACK_BIAS);
 161                 if (!(regs->tstate & TSTATE_PRIV)) {
 162                         old_fs = get_fs();
 163                         set_fs (USER_DS);
 164                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 165                                 set_fs (old_fs);
 166                                 return;
 167                         }
 168                         rwk = &r_w;
 169                         set_fs (old_fs);
 170                 }
 171         } else {
 172                 show_regwindow32(regs);
 173                 return;
 174         }
 175         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 176                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 177         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 178                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 179         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 180                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 181         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 182                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 183         if (regs->tstate & TSTATE_PRIV)
 184                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 185 }
 186
 187 void show_regs(struct pt_regs *regs)
 188 {
 189         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 190                regs->tpc, regs->tnpc, regs->y, print_tainted());
 191         printk("TPC: <%pS>\n", (void *) regs->tpc);
 192         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 193                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 194                regs->u_regs[3]);
 195         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 196                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 197                regs->u_regs[7]);
 198         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 199                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 200                regs->u_regs[11]);
 201         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 202                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 203                regs->u_regs[15]);
 204         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 205         show_regwindow(regs);
 206         show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
 207 }
 208
 209 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
 210 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
 211
 212 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 213                               int this_cpu)
 214 {
 215         struct global_reg_snapshot *rp;
 216
 217         flushw_all();
 218
 219         rp = &global_cpu_snapshot[this_cpu].reg;
 220
 221         rp->tstate = regs->tstate;
 222         rp->tpc = regs->tpc;
 223         rp->tnpc = regs->tnpc;
 224         rp->o7 = regs->u_regs[UREG_I7];
 225
 226         if (regs->tstate & TSTATE_PRIV) {
 227                 struct reg_window *rw;
 228
 229                 rw = (struct reg_window *)
 230                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 231                 if (kstack_valid(tp, (unsigned long) rw)) {
 232                         rp->i7 = rw->ins[7];
 233                         rw = (struct reg_window *)
 234                                 (rw->ins[6] + STACK_BIAS);
 235                         if (kstack_valid(tp, (unsigned long) rw))
 236                                 rp->rpc = rw->ins[7];
 237                 }
 238         } else {
 239                 rp->i7 = 0;
 240                 rp->rpc = 0;
 241         }
 242         rp->thread = tp;
 243 }
 244
 245 /* In order to avoid hangs we do not try to synchronize with the
 246  * global register dump client cpus.  The last store they make is to
 247  * the thread pointer, so do a short poll waiting for that to become
 248  * non-NULL.
 249  */
 250 static void __global_reg_poll(struct global_reg_snapshot *gp)
 251 {
 252         int limit = 0;
 253
 254         while (!gp->thread && ++limit < 100) {
 255                 barrier();
 256                 udelay(1);
 257         }
 258 }
 259
 260 void arch_trigger_all_cpu_backtrace(void)
 261 {
 262         struct thread_info *tp = current_thread_info();
 263         struct pt_regs *regs = get_irq_regs();
 264         unsigned long flags;
 265         int this_cpu, cpu;
 266
 267         if (!regs)
 268                 regs = tp->kregs;
 269
 270         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 271
 272         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 273
 274         this_cpu = raw_smp_processor_id();
 275
 276         __global_reg_self(tp, regs, this_cpu);
 277
 278         smp_fetch_global_regs();
 279
 280         for_each_online_cpu(cpu) {
 281                 struct global_reg_snapshot *gp = &global_cpu_snapshot[cpu].reg;
 282
 283                 __global_reg_poll(gp);
 284
 285                 tp = gp->thread;
 286                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 287                        (cpu == this_cpu ? '*' : ' '), cpu,
 288                        gp->tstate, gp->tpc, gp->tnpc,
 289                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 290                        ((tp && tp->task) ? tp->task->pid : -1));
 291
 292                 if (gp->tstate & TSTATE_PRIV) {
 293                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 294                                (void *) gp->tpc,
 295                                (void *) gp->o7,
 296                                (void *) gp->i7,
 297                                (void *) gp->rpc);
 298                 } else {
 299                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 300                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 301                 }
 302         }
 303
 304         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 305
 306         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 307 }
 308
 309 #ifdef CONFIG_MAGIC_SYSRQ
 310
 311 static void sysrq_handle_globreg(int key)
 312 {
 313         arch_trigger_all_cpu_backtrace();
 314 }
 315
 316 static struct sysrq_key_op sparc_globalreg_op = {
 317         .handler        = sysrq_handle_globreg,
 318         .help_msg       = "global-regs(Y)",
 319         .action_msg     = "Show Global CPU Regs",
 320 };
 321
 322 static void __global_pmu_self(int this_cpu)
 323 {
 324         struct global_pmu_snapshot *pp;
 325         int i, num;
 326
 327         pp = &global_cpu_snapshot[this_cpu].pmu;
 328
 329         num = 1;
 330         if (tlb_type == hypervisor &&
 331             sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
 332                 num = 4;
 333
 334         for (i = 0; i < num; i++) {
 335                 pp->pcr[i] = pcr_ops->read_pcr(i);
 336                 pp->pic[i] = pcr_ops->read_pic(i);
 337         }
 338 }
 339
 340 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
 341 {
 342         int limit = 0;
 343
 344         while (!pp->pcr[0] && ++limit < 100) {
 345                 barrier();
 346                 udelay(1);
 347         }
 348 }
 349
 350 static void pmu_snapshot_all_cpus(void)
 351 {
 352         unsigned long flags;
 353         int this_cpu, cpu;
 354
 355         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 356
 357         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 358
 359         this_cpu = raw_smp_processor_id();
 360
 361         __global_pmu_self(this_cpu);
 362
 363         smp_fetch_global_pmu();
 364
 365         for_each_online_cpu(cpu) {
 366                 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
 367
 368                 __global_pmu_poll(pp);
 369
 370                 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
 371                        (cpu == this_cpu ? '*' : ' '), cpu,
 372                        pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
 373                        pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
 374         }
 375
 376         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 377
 378         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 379 }
 380
 381 static void sysrq_handle_globpmu(int key)
 382 {
 383         pmu_snapshot_all_cpus();
 384 }
 385
 386 static struct sysrq_key_op sparc_globalpmu_op = {
 387         .handler        = sysrq_handle_globpmu,
 388         .help_msg       = "global-pmu(X)",
 389         .action_msg     = "Show Global PMU Regs",
 390 };
 391
 392 static int __init sparc_sysrq_init(void)
 393 {
 394         int ret = register_sysrq_key('y', &sparc_globalreg_op);
 395
 396         if (!ret)
 397                 ret = register_sysrq_key('x', &sparc_globalpmu_op);
 398         return ret;
 399 }
 400
 401 core_initcall(sparc_sysrq_init);
 402
 403 #endif
 404
 405 unsigned long thread_saved_pc(struct task_struct *tsk)
 406 {
 407         struct thread_info *ti = task_thread_info(tsk);
 408         unsigned long ret = 0xdeadbeefUL;
 409
 410         if (ti && ti->ksp) {
 411                 unsigned long *sp;
 412                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 413                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 414                     sp[14]) {
 415                         unsigned long *fp;
 416                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 417                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 418                                 ret = fp[15];
 419                 }
 420         }
 421         return ret;
 422 }
 423
 424 /* Free current thread data structures etc.. */
 425 void exit_thread(void)
 426 {
 427         struct thread_info *t = current_thread_info();
 428
 429         if (t->utraps) {
 430                 if (t->utraps[0] < 2)
 431                         kfree (t->utraps);
 432                 else
 433                         t->utraps[0]--;
 434         }
 435 }
 436
 437 void flush_thread(void)
 438 {
 439         struct thread_info *t = current_thread_info();
 440         struct mm_struct *mm;
 441
 442         mm = t->task->mm;
 443         if (mm)
 444                 tsb_context_switch(mm);
 445
 446         set_thread_wsaved(0);
 447
 448         /* Clear FPU register state. */
 449         t->fpsaved[0] = 0;
 450 }
 451
 452 /* It's a bit more tricky when 64-bit tasks are involved... */
 453 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 454 {
 455         unsigned long fp, distance, rval;
 456
 457         if (!(test_thread_flag(TIF_32BIT))) {
 458                 csp += STACK_BIAS;
 459                 psp += STACK_BIAS;
 460                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 461                 fp += STACK_BIAS;
 462         } else
 463                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 464
 465         /* Now align the stack as this is mandatory in the Sparc ABI
 466          * due to how register windows work.  This hides the
 467          * restriction from thread libraries etc.
 468          */
 469         csp &= ~15UL;
 470
 471         distance = fp - psp;
 472         rval = (csp - distance);
 473         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 474                 rval = 0;
 475         else if (test_thread_flag(TIF_32BIT)) {
 476                 if (put_user(((u32)csp),
 477                              &(((struct reg_window32 __user *)rval)->ins[6])))
 478                         rval = 0;
 479         } else {
 480                 if (put_user(((u64)csp - STACK_BIAS),
 481                              &(((struct reg_window __user *)rval)->ins[6])))
 482                         rval = 0;
 483                 else
 484                         rval = rval - STACK_BIAS;
 485         }
 486
 487         return rval;
 488 }
 489
 490 /* Standard stuff. */
 491 static inline void shift_window_buffer(int first_win, int last_win,
 492                                        struct thread_info *t)
 493 {
 494         int i;
 495
 496         for (i = first_win; i < last_win; i++) {
 497                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 498                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 499                        sizeof(struct reg_window));
 500         }
 501 }
 502
 503 void synchronize_user_stack(void)
 504 {
 505         struct thread_info *t = current_thread_info();
 506         unsigned long window;
 507
 508         flush_user_windows();
 509         if ((window = get_thread_wsaved()) != 0) {
 510                 int winsize = sizeof(struct reg_window);
 511                 int bias = 0;
 512
 513                 if (test_thread_flag(TIF_32BIT))
 514                         winsize = sizeof(struct reg_window32);
 515                 else
 516                         bias = STACK_BIAS;
 517
 518                 window -= 1;
 519                 do {
 520                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 521                         struct reg_window *rwin = &t->reg_window[window];
 522
 523                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 524                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 525                                 set_thread_wsaved(get_thread_wsaved() - 1);
 526                         }
 527                 } while (window--);
 528         }
 529 }
 530
 531 static void stack_unaligned(unsigned long sp)
 532 {
 533         siginfo_t info;
 534
 535         info.si_signo = SIGBUS;
 536         info.si_errno = 0;
 537         info.si_code = BUS_ADRALN;
 538         info.si_addr = (void __user *) sp;
 539         info.si_trapno = 0;
 540         force_sig_info(SIGBUS, &info, current);
 541 }
 542
 543 void fault_in_user_windows(void)
 544 {
 545         struct thread_info *t = current_thread_info();
 546         unsigned long window;
 547         int winsize = sizeof(struct reg_window);
 548         int bias = 0;
 549
 550         if (test_thread_flag(TIF_32BIT))
 551                 winsize = sizeof(struct reg_window32);
 552         else
 553                 bias = STACK_BIAS;
 554
 555         flush_user_windows();
 556         window = get_thread_wsaved();
 557
 558         if (likely(window != 0)) {
 559                 window -= 1;
 560                 do {
 561                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 562                         struct reg_window *rwin = &t->reg_window[window];
 563
 564                         if (unlikely(sp & 0x7UL))
 565                                 stack_unaligned(sp);
 566
 567                         if (unlikely(copy_to_user((char __user *)sp,
 568                                                   rwin, winsize)))
 569                                 goto barf;
 570                 } while (window--);
 571         }
 572         set_thread_wsaved(0);
 573         return;
 574
 575 barf:
 576         set_thread_wsaved(window + 1);
 577         do_exit(SIGILL);
 578 }
 579
 580 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 581                               unsigned long stack_start,
 582                               struct pt_regs *regs,
 583                               unsigned long stack_size)
 584 {
 585         int __user *parent_tid_ptr, *child_tid_ptr;
 586         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 587         long ret;
 588
 589 #ifdef CONFIG_COMPAT
 590         if (test_thread_flag(TIF_32BIT)) {
 591                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 592                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 593         } else
 594 #endif
 595         {
 596                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 597                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 598         }
 599
 600         ret = do_fork(clone_flags, stack_start,
 601                       regs, stack_size,
 602                       parent_tid_ptr, child_tid_ptr);
 603
 604         /* If we get an error and potentially restart the system
 605          * call, we're screwed because copy_thread() clobbered
 606          * the parent's %o1.  So detect that case and restore it
 607          * here.
 608          */
 609         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 610                 regs->u_regs[UREG_I1] = orig_i1;
 611
 612         return ret;
 613 }
 614
 615 /* Copy a Sparc thread.  The fork() return value conventions
 616  * under SunOS are nothing short of bletcherous:
 617  * Parent -->  %o0 == childs  pid, %o1 == 0
 618  * Child  -->  %o0 == parents pid, %o1 == 1
 619  */
 620 int copy_thread(unsigned long clone_flags, unsigned long sp,
 621                 unsigned long unused,
 622                 struct task_struct *p, struct pt_regs *regs)
 623 {
 624         struct thread_info *t = task_thread_info(p);
 625         struct sparc_stackf *parent_sf;
 626         unsigned long child_stack_sz;
 627         char *child_trap_frame;
 628         int kernel_thread;
 629
 630         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 631         parent_sf = ((struct sparc_stackf *) regs) - 1;
 632
 633         /* Calculate offset to stack_frame & pt_regs */
 634         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 635                           (kernel_thread ? STACKFRAME_SZ : 0));
 636         child_trap_frame = (task_stack_page(p) +
 637                             (THREAD_SIZE - child_stack_sz));
 638         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 639
 640         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 641                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 642                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 643         t->new_child = 1;
 644         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 645         t->kregs = (struct pt_regs *) (child_trap_frame +
 646                                        sizeof(struct sparc_stackf));
 647         t->fpsaved[0] = 0;
 648
 649         if (kernel_thread) {
 650                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 651                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 652
 653                 /* Zero terminate the stack backtrace.  */
 654                 child_sf->fp = NULL;
 655                 t->kregs->u_regs[UREG_FP] =
 656                   ((unsigned long) child_sf) - STACK_BIAS;
 657
 658                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 659                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 660                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 661         } else {
 662                 if (t->flags & _TIF_32BIT) {
 663                         sp &= 0x00000000ffffffffUL;
 664                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 665                 }
 666                 t->kregs->u_regs[UREG_FP] = sp;
 667                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 668                 if (sp != regs->u_regs[UREG_FP]) {
 669                         unsigned long csp;
 670
 671                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 672                         if (!csp)
 673                                 return -EFAULT;
 674                         t->kregs->u_regs[UREG_FP] = csp;
 675                 }
 676                 if (t->utraps)
 677                         t->utraps[0]++;
 678         }
 679
 680         /* Set the return value for the child. */
 681         t->kregs->u_regs[UREG_I0] = current->pid;
 682         t->kregs->u_regs[UREG_I1] = 1;
 683
 684         /* Set the second return value for the parent. */
 685         regs->u_regs[UREG_I1] = 0;
 686
 687         if (clone_flags & CLONE_SETTLS)
 688                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 689
 690         return 0;
 691 }
 692
 693 /*
 694  * This is the mechanism for creating a new kernel thread.
 695  *
 696  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 697  * who haven't done an "execve()") should use this: it will work within
 698  * a system call from a "real" process, but the process memory space will
 699  * not be freed until both the parent and the child have exited.
 700  */
 701 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 702 {
 703         long retval;
 704
 705         /* If the parent runs before fn(arg) is called by the child,
 706          * the input registers of this function can be clobbered.
 707          * So we stash 'fn' and 'arg' into global registers which
 708          * will not be modified by the parent.
 709          */
 710         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 711                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 712                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 713                              "mov %2, %%o0\n\t"    /* Clone flags. */
 714                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 715                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 716                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 717                              " mov %%o0, %0\n\t"
 718                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 719                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 720                              "mov %3, %%g1\n\t"
 721                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 722                              /* Notreached by child. */
 723                              "1:" :
 724                              "=r" (retval) :
 725                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 726                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 727                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 728         return retval;
 729 }
 730 EXPORT_SYMBOL(kernel_thread);
 731
 732 typedef struct {
 733         union {
 734                 unsigned int    pr_regs[32];
 735                 unsigned long   pr_dregs[16];
 736         } pr_fr;
 737         unsigned int __unused;
 738         unsigned int    pr_fsr;
 739         unsigned char   pr_qcnt;
 740         unsigned char   pr_q_entrysize;
 741         unsigned char   pr_en;
 742         unsigned int    pr_q[64];
 743 } elf_fpregset_t32;
 744
 745 /*
 746  * fill in the fpu structure for a core dump.
 747  */
 748 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 749 {
 750         unsigned long *kfpregs = current_thread_info()->fpregs;
 751         unsigned long fprs = current_thread_info()->fpsaved[0];
 752
 753         if (test_thread_flag(TIF_32BIT)) {
 754                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 755
 756                 if (fprs & FPRS_DL)
 757                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 758                                sizeof(unsigned int) * 32);
 759                 else
 760                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 761                                sizeof(unsigned int) * 32);
 762                 fpregs32->pr_qcnt = 0;
 763                 fpregs32->pr_q_entrysize = 8;
 764                 memset(&fpregs32->pr_q[0], 0,
 765                        (sizeof(unsigned int) * 64));
 766                 if (fprs & FPRS_FEF) {
 767                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 768                         fpregs32->pr_en = 1;
 769                 } else {
 770                         fpregs32->pr_fsr = 0;
 771                         fpregs32->pr_en = 0;
 772                 }
 773         } else {
 774                 if(fprs & FPRS_DL)
 775                         memcpy(&fpregs->pr_regs[0], kfpregs,
 776                                sizeof(unsigned int) * 32);
 777                 else
 778                         memset(&fpregs->pr_regs[0], 0,
 779                                sizeof(unsigned int) * 32);
 780                 if(fprs & FPRS_DU)
 781                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 782                                sizeof(unsigned int) * 32);
 783                 else
 784                         memset(&fpregs->pr_regs[16], 0,
 785                                sizeof(unsigned int) * 32);
 786                 if(fprs & FPRS_FEF) {
 787                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 788                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 789                 } else {
 790                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 791                 }
 792                 fpregs->pr_fprs = fprs;
 793         }
 794         return 1;
 795 }
 796 EXPORT_SYMBOL(dump_fpu);
 797
 798 /*
 799  * sparc_execve() executes a new program after the asm stub has set
 800  * things up for us.  This should basically do what I want it to.
 801  */
 802 asmlinkage int sparc_execve(struct pt_regs *regs)
 803 {
 804         int error, base = 0;
 805         struct filename *filename;
 806
 807         /* User register window flush is done by entry.S */
 808
 809         /* Check for indirect call. */
 810         if (regs->u_regs[UREG_G1] == 0)
 811                 base = 1;
 812
 813         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 814         error = PTR_ERR(filename);
 815         if (IS_ERR(filename))
 816                 goto out;
 817         error = do_execve(filename->name,
 818                           (const char __user *const __user *)
 819                           regs->u_regs[base + UREG_I1],
 820                           (const char __user *const __user *)
 821                           regs->u_regs[base + UREG_I2], regs);
 822         putname(filename);
 823         if (!error) {
 824                 fprs_write(0);
 825                 current_thread_info()->xfsr[0] = 0;
 826                 current_thread_info()->fpsaved[0] = 0;
 827                 regs->tstate &= ~TSTATE_PEF;
 828         }
 829 out:
 830         return error;
 831 }
 832
 833 unsigned long get_wchan(struct task_struct *task)
 834 {
 835         unsigned long pc, fp, bias = 0;
 836         struct thread_info *tp;
 837         struct reg_window *rw;
 838         unsigned long ret = 0;
 839         int count = 0;
 840
 841         if (!task || task == current ||
 842             task->state == TASK_RUNNING)
 843                 goto out;
 844
 845         tp = task_thread_info(task);
 846         bias = STACK_BIAS;
 847         fp = task_thread_info(task)->ksp + bias;
 848
 849         do {
 850                 if (!kstack_valid(tp, fp))
 851                         break;
 852                 rw = (struct reg_window *) fp;
 853                 pc = rw->ins[7];
 854                 if (!in_sched_functions(pc)) {
 855                         ret = pc;
 856                         goto out;
 857                 }
 858                 fp = rw->ins[6] + bias;
 859         } while (++count < 16);
 860
 861 out:
 862         return ret;
 863 }