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