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   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
  33 #include <asm/uaccess.h>
  34 #include <asm/system.h>
  35 #include <asm/page.h>
  36 #include <asm/pgalloc.h>
  37 #include <asm/pgtable.h>
  38 #include <asm/processor.h>
  39 #include <asm/pstate.h>
  40 #include <asm/elf.h>
  41 #include <asm/fpumacro.h>
  42 #include <asm/head.h>
  43 #include <asm/cpudata.h>
  44 #include <asm/mmu_context.h>
  45 #include <asm/unistd.h>
  46 #include <asm/hypervisor.h>
  47 #include <asm/syscalls.h>
  48 #include <asm/irq_regs.h>
  49 #include <asm/smp.h>
  50
  51 #include "kstack.h"
  52
  53 static void sparc64_yield(int cpu)
  54 {
  55         if (tlb_type != hypervisor)
  56                 return;
  57
  58         clear_thread_flag(TIF_POLLING_NRFLAG);
  59         smp_mb__after_clear_bit();
  60
  61         while (!need_resched() && !cpu_is_offline(cpu)) {
  62                 unsigned long pstate;
  63
  64                 /* Disable interrupts. */
  65                 __asm__ __volatile__(
  66                         "rdpr %%pstate, %0\n\t"
  67                         "andn %0, %1, %0\n\t"
  68                         "wrpr %0, %%g0, %%pstate"
  69                         : "=&r" (pstate)
  70                         : "i" (PSTATE_IE));
  71
  72                 if (!need_resched() && !cpu_is_offline(cpu))
  73                         sun4v_cpu_yield();
  74
  75                 /* Re-enable interrupts. */
  76                 __asm__ __volatile__(
  77                         "rdpr %%pstate, %0\n\t"
  78                         "or %0, %1, %0\n\t"
  79                         "wrpr %0, %%g0, %%pstate"
  80                         : "=&r" (pstate)
  81                         : "i" (PSTATE_IE));
  82         }
  83
  84         set_thread_flag(TIF_POLLING_NRFLAG);
  85 }
  86
  87 /* The idle loop on sparc64. */
  88 void cpu_idle(void)
  89 {
  90         int cpu = smp_processor_id();
  91
  92         set_thread_flag(TIF_POLLING_NRFLAG);
  93
  94         while(1) {
  95                 tick_nohz_stop_sched_tick(1);
  96
  97                 while (!need_resched() && !cpu_is_offline(cpu))
  98                         sparc64_yield(cpu);
  99
 100                 tick_nohz_restart_sched_tick();
 101
 102                 preempt_enable_no_resched();
 103
 104 #ifdef CONFIG_HOTPLUG_CPU
 105                 if (cpu_is_offline(cpu))
 106                         cpu_play_dead();
 107 #endif
 108
 109                 schedule();
 110                 preempt_disable();
 111         }
 112 }
 113
 114 #ifdef CONFIG_COMPAT
 115 static void show_regwindow32(struct pt_regs *regs)
 116 {
 117         struct reg_window32 __user *rw;
 118         struct reg_window32 r_w;
 119         mm_segment_t old_fs;
 120
 121         __asm__ __volatile__ ("flushw");
 122         rw = compat_ptr((unsigned)regs->u_regs[14]);
 123         old_fs = get_fs();
 124         set_fs (USER_DS);
 125         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 126                 set_fs (old_fs);
 127                 return;
 128         }
 129
 130         set_fs (old_fs);
 131         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 132                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 133                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 134                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 135         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 136                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 137                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 138                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 139 }
 140 #else
 141 #define show_regwindow32(regs)  do { } while (0)
 142 #endif
 143
 144 static void show_regwindow(struct pt_regs *regs)
 145 {
 146         struct reg_window __user *rw;
 147         struct reg_window *rwk;
 148         struct reg_window r_w;
 149         mm_segment_t old_fs;
 150
 151         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 152                 __asm__ __volatile__ ("flushw");
 153                 rw = (struct reg_window __user *)
 154                         (regs->u_regs[14] + STACK_BIAS);
 155                 rwk = (struct reg_window *)
 156                         (regs->u_regs[14] + STACK_BIAS);
 157                 if (!(regs->tstate & TSTATE_PRIV)) {
 158                         old_fs = get_fs();
 159                         set_fs (USER_DS);
 160                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 161                                 set_fs (old_fs);
 162                                 return;
 163                         }
 164                         rwk = &r_w;
 165                         set_fs (old_fs);
 166                 }
 167         } else {
 168                 show_regwindow32(regs);
 169                 return;
 170         }
 171         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 172                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 173         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 174                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 175         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 176                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 177         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 178                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 179         if (regs->tstate & TSTATE_PRIV)
 180                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 181 }
 182
 183 void show_regs(struct pt_regs *regs)
 184 {
 185         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 186                regs->tpc, regs->tnpc, regs->y, print_tainted());
 187         printk("TPC: <%pS>\n", (void *) regs->tpc);
 188         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 189                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 190                regs->u_regs[3]);
 191         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 192                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 193                regs->u_regs[7]);
 194         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 195                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 196                regs->u_regs[11]);
 197         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 198                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 199                regs->u_regs[15]);
 200         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 201         show_regwindow(regs);
 202 }
 203
 204 struct global_reg_snapshot global_reg_snapshot[NR_CPUS];
 205 static DEFINE_SPINLOCK(global_reg_snapshot_lock);
 206
 207 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 208                               int this_cpu)
 209 {
 210         flushw_all();
 211
 212         global_reg_snapshot[this_cpu].tstate = regs->tstate;
 213         global_reg_snapshot[this_cpu].tpc = regs->tpc;
 214         global_reg_snapshot[this_cpu].tnpc = regs->tnpc;
 215         global_reg_snapshot[this_cpu].o7 = regs->u_regs[UREG_I7];
 216
 217         if (regs->tstate & TSTATE_PRIV) {
 218                 struct reg_window *rw;
 219
 220                 rw = (struct reg_window *)
 221                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 222                 if (kstack_valid(tp, (unsigned long) rw)) {
 223                         global_reg_snapshot[this_cpu].i7 = rw->ins[7];
 224                         rw = (struct reg_window *)
 225                                 (rw->ins[6] + STACK_BIAS);
 226                         if (kstack_valid(tp, (unsigned long) rw))
 227                                 global_reg_snapshot[this_cpu].rpc = rw->ins[7];
 228                 }
 229         } else {
 230                 global_reg_snapshot[this_cpu].i7 = 0;
 231                 global_reg_snapshot[this_cpu].rpc = 0;
 232         }
 233         global_reg_snapshot[this_cpu].thread = tp;
 234 }
 235
 236 /* In order to avoid hangs we do not try to synchronize with the
 237  * global register dump client cpus.  The last store they make is to
 238  * the thread pointer, so do a short poll waiting for that to become
 239  * non-NULL.
 240  */
 241 static void __global_reg_poll(struct global_reg_snapshot *gp)
 242 {
 243         int limit = 0;
 244
 245         while (!gp->thread && ++limit < 100) {
 246                 barrier();
 247                 udelay(1);
 248         }
 249 }
 250
 251 void __trigger_all_cpu_backtrace(void)
 252 {
 253         struct thread_info *tp = current_thread_info();
 254         struct pt_regs *regs = get_irq_regs();
 255         unsigned long flags;
 256         int this_cpu, cpu;
 257
 258         if (!regs)
 259                 regs = tp->kregs;
 260
 261         spin_lock_irqsave(&global_reg_snapshot_lock, flags);
 262
 263         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 264
 265         this_cpu = raw_smp_processor_id();
 266
 267         __global_reg_self(tp, regs, this_cpu);
 268
 269         smp_fetch_global_regs();
 270
 271         for_each_online_cpu(cpu) {
 272                 struct global_reg_snapshot *gp = &global_reg_snapshot[cpu];
 273
 274                 __global_reg_poll(gp);
 275
 276                 tp = gp->thread;
 277                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 278                        (cpu == this_cpu ? '*' : ' '), cpu,
 279                        gp->tstate, gp->tpc, gp->tnpc,
 280                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 281                        ((tp && tp->task) ? tp->task->pid : -1));
 282
 283                 if (gp->tstate & TSTATE_PRIV) {
 284                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 285                                (void *) gp->tpc,
 286                                (void *) gp->o7,
 287                                (void *) gp->i7,
 288                                (void *) gp->rpc);
 289                 } else {
 290                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 291                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 292                 }
 293         }
 294
 295         memset(global_reg_snapshot, 0, sizeof(global_reg_snapshot));
 296
 297         spin_unlock_irqrestore(&global_reg_snapshot_lock, flags);
 298 }
 299
 300 #ifdef CONFIG_MAGIC_SYSRQ
 301
 302 static void sysrq_handle_globreg(int key, struct tty_struct *tty)
 303 {
 304         __trigger_all_cpu_backtrace();
 305 }
 306
 307 static struct sysrq_key_op sparc_globalreg_op = {
 308         .handler        = sysrq_handle_globreg,
 309         .help_msg       = "Globalregs",
 310         .action_msg     = "Show Global CPU Regs",
 311 };
 312
 313 static int __init sparc_globreg_init(void)
 314 {
 315         return register_sysrq_key('y', &sparc_globalreg_op);
 316 }
 317
 318 core_initcall(sparc_globreg_init);
 319
 320 #endif
 321
 322 unsigned long thread_saved_pc(struct task_struct *tsk)
 323 {
 324         struct thread_info *ti = task_thread_info(tsk);
 325         unsigned long ret = 0xdeadbeefUL;
 326
 327         if (ti && ti->ksp) {
 328                 unsigned long *sp;
 329                 sp = (unsigned long *)(ti->ksp + STACK_BIAS);
 330                 if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
 331                     sp[14]) {
 332                         unsigned long *fp;
 333                         fp = (unsigned long *)(sp[14] + STACK_BIAS);
 334                         if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
 335                                 ret = fp[15];
 336                 }
 337         }
 338         return ret;
 339 }
 340
 341 /* Free current thread data structures etc.. */
 342 void exit_thread(void)
 343 {
 344         struct thread_info *t = current_thread_info();
 345
 346         if (t->utraps) {
 347                 if (t->utraps[0] < 2)
 348                         kfree (t->utraps);
 349                 else
 350                         t->utraps[0]--;
 351         }
 352
 353         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 354                 t->user_cntd0 = t->user_cntd1 = NULL;
 355                 t->pcr_reg = 0;
 356                 write_pcr(0);
 357         }
 358 }
 359
 360 void flush_thread(void)
 361 {
 362         struct thread_info *t = current_thread_info();
 363         struct mm_struct *mm;
 364
 365         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
 366                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
 367                 if (test_ti_thread_flag(t, TIF_32BIT))
 368                         clear_ti_thread_flag(t, TIF_32BIT);
 369                 else
 370                         set_ti_thread_flag(t, TIF_32BIT);
 371         }
 372
 373         mm = t->task->mm;
 374         if (mm)
 375                 tsb_context_switch(mm);
 376
 377         set_thread_wsaved(0);
 378
 379         /* Turn off performance counters if on. */
 380         if (test_and_clear_thread_flag(TIF_PERFCTR)) {
 381                 t->user_cntd0 = t->user_cntd1 = NULL;
 382                 t->pcr_reg = 0;
 383                 write_pcr(0);
 384         }
 385
 386         /* Clear FPU register state. */
 387         t->fpsaved[0] = 0;
 388
 389         if (get_thread_current_ds() != ASI_AIUS)
 390                 set_fs(USER_DS);
 391 }
 392
 393 /* It's a bit more tricky when 64-bit tasks are involved... */
 394 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 395 {
 396         unsigned long fp, distance, rval;
 397
 398         if (!(test_thread_flag(TIF_32BIT))) {
 399                 csp += STACK_BIAS;
 400                 psp += STACK_BIAS;
 401                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 402                 fp += STACK_BIAS;
 403         } else
 404                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 405
 406         /* Now 8-byte align the stack as this is mandatory in the
 407          * Sparc ABI due to how register windows work.  This hides
 408          * the restriction from thread libraries etc.  -DaveM
 409          */
 410         csp &= ~7UL;
 411
 412         distance = fp - psp;
 413         rval = (csp - distance);
 414         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 415                 rval = 0;
 416         else if (test_thread_flag(TIF_32BIT)) {
 417                 if (put_user(((u32)csp),
 418                              &(((struct reg_window32 __user *)rval)->ins[6])))
 419                         rval = 0;
 420         } else {
 421                 if (put_user(((u64)csp - STACK_BIAS),
 422                              &(((struct reg_window __user *)rval)->ins[6])))
 423                         rval = 0;
 424                 else
 425                         rval = rval - STACK_BIAS;
 426         }
 427
 428         return rval;
 429 }
 430
 431 /* Standard stuff. */
 432 static inline void shift_window_buffer(int first_win, int last_win,
 433                                        struct thread_info *t)
 434 {
 435         int i;
 436
 437         for (i = first_win; i < last_win; i++) {
 438                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 439                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 440                        sizeof(struct reg_window));
 441         }
 442 }
 443
 444 void synchronize_user_stack(void)
 445 {
 446         struct thread_info *t = current_thread_info();
 447         unsigned long window;
 448
 449         flush_user_windows();
 450         if ((window = get_thread_wsaved()) != 0) {
 451                 int winsize = sizeof(struct reg_window);
 452                 int bias = 0;
 453
 454                 if (test_thread_flag(TIF_32BIT))
 455                         winsize = sizeof(struct reg_window32);
 456                 else
 457                         bias = STACK_BIAS;
 458
 459                 window -= 1;
 460                 do {
 461                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 462                         struct reg_window *rwin = &t->reg_window[window];
 463
 464                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 465                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 466                                 set_thread_wsaved(get_thread_wsaved() - 1);
 467                         }
 468                 } while (window--);
 469         }
 470 }
 471
 472 static void stack_unaligned(unsigned long sp)
 473 {
 474         siginfo_t info;
 475
 476         info.si_signo = SIGBUS;
 477         info.si_errno = 0;
 478         info.si_code = BUS_ADRALN;
 479         info.si_addr = (void __user *) sp;
 480         info.si_trapno = 0;
 481         force_sig_info(SIGBUS, &info, current);
 482 }
 483
 484 void fault_in_user_windows(void)
 485 {
 486         struct thread_info *t = current_thread_info();
 487         unsigned long window;
 488         int winsize = sizeof(struct reg_window);
 489         int bias = 0;
 490
 491         if (test_thread_flag(TIF_32BIT))
 492                 winsize = sizeof(struct reg_window32);
 493         else
 494                 bias = STACK_BIAS;
 495
 496         flush_user_windows();
 497         window = get_thread_wsaved();
 498
 499         if (likely(window != 0)) {
 500                 window -= 1;
 501                 do {
 502                         unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
 503                         struct reg_window *rwin = &t->reg_window[window];
 504
 505                         if (unlikely(sp & 0x7UL))
 506                                 stack_unaligned(sp);
 507
 508                         if (unlikely(copy_to_user((char __user *)sp,
 509                                                   rwin, winsize)))
 510                                 goto barf;
 511                 } while (window--);
 512         }
 513         set_thread_wsaved(0);
 514         return;
 515
 516 barf:
 517         set_thread_wsaved(window + 1);
 518         do_exit(SIGILL);
 519 }
 520
 521 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 522                               unsigned long stack_start,
 523                               struct pt_regs *regs,
 524                               unsigned long stack_size)
 525 {
 526         int __user *parent_tid_ptr, *child_tid_ptr;
 527         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 528         long ret;
 529
 530 #ifdef CONFIG_COMPAT
 531         if (test_thread_flag(TIF_32BIT)) {
 532                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 533                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 534         } else
 535 #endif
 536         {
 537                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 538                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 539         }
 540
 541         ret = do_fork(clone_flags, stack_start,
 542                       regs, stack_size,
 543                       parent_tid_ptr, child_tid_ptr);
 544
 545         /* If we get an error and potentially restart the system
 546          * call, we're screwed because copy_thread() clobbered
 547          * the parent's %o1.  So detect that case and restore it
 548          * here.
 549          */
 550         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 551                 regs->u_regs[UREG_I1] = orig_i1;
 552
 553         return ret;
 554 }
 555
 556 /* Copy a Sparc thread.  The fork() return value conventions
 557  * under SunOS are nothing short of bletcherous:
 558  * Parent -->  %o0 == childs  pid, %o1 == 0
 559  * Child  -->  %o0 == parents pid, %o1 == 1
 560  */
 561 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
 562                 unsigned long unused,
 563                 struct task_struct *p, struct pt_regs *regs)
 564 {
 565         struct thread_info *t = task_thread_info(p);
 566         struct sparc_stackf *parent_sf;
 567         unsigned long child_stack_sz;
 568         char *child_trap_frame;
 569         int kernel_thread;
 570
 571         kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
 572         parent_sf = ((struct sparc_stackf *) regs) - 1;
 573
 574         /* Calculate offset to stack_frame & pt_regs */
 575         child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
 576                           (kernel_thread ? STACKFRAME_SZ : 0));
 577         child_trap_frame = (task_stack_page(p) +
 578                             (THREAD_SIZE - child_stack_sz));
 579         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 580
 581         t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
 582                                  (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
 583                 (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 584         t->new_child = 1;
 585         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 586         t->kregs = (struct pt_regs *) (child_trap_frame +
 587                                        sizeof(struct sparc_stackf));
 588         t->fpsaved[0] = 0;
 589
 590         if (kernel_thread) {
 591                 struct sparc_stackf *child_sf = (struct sparc_stackf *)
 592                         (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
 593
 594                 /* Zero terminate the stack backtrace.  */
 595                 child_sf->fp = NULL;
 596                 t->kregs->u_regs[UREG_FP] =
 597                   ((unsigned long) child_sf) - STACK_BIAS;
 598
 599                 /* Special case, if we are spawning a kernel thread from
 600                  * a userspace task (usermode helper, NFS or similar), we
 601                  * must disable performance counters in the child because
 602                  * the address space and protection realm are changing.
 603                  */
 604                 if (t->flags & _TIF_PERFCTR) {
 605                         t->user_cntd0 = t->user_cntd1 = NULL;
 606                         t->pcr_reg = 0;
 607                         t->flags &= ~_TIF_PERFCTR;
 608                 }
 609                 t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
 610                 t->kregs->u_regs[UREG_G6] = (unsigned long) t;
 611                 t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
 612         } else {
 613                 if (t->flags & _TIF_32BIT) {
 614                         sp &= 0x00000000ffffffffUL;
 615                         regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 616                 }
 617                 t->kregs->u_regs[UREG_FP] = sp;
 618                 t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
 619                 if (sp != regs->u_regs[UREG_FP]) {
 620                         unsigned long csp;
 621
 622                         csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 623                         if (!csp)
 624                                 return -EFAULT;
 625                         t->kregs->u_regs[UREG_FP] = csp;
 626                 }
 627                 if (t->utraps)
 628                         t->utraps[0]++;
 629         }
 630
 631         /* Set the return value for the child. */
 632         t->kregs->u_regs[UREG_I0] = current->pid;
 633         t->kregs->u_regs[UREG_I1] = 1;
 634
 635         /* Set the second return value for the parent. */
 636         regs->u_regs[UREG_I1] = 0;
 637
 638         if (clone_flags & CLONE_SETTLS)
 639                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 640
 641         return 0;
 642 }
 643
 644 /*
 645  * This is the mechanism for creating a new kernel thread.
 646  *
 647  * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 648  * who haven't done an "execve()") should use this: it will work within
 649  * a system call from a "real" process, but the process memory space will
 650  * not be freed until both the parent and the child have exited.
 651  */
 652 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
 653 {
 654         long retval;
 655
 656         /* If the parent runs before fn(arg) is called by the child,
 657          * the input registers of this function can be clobbered.
 658          * So we stash 'fn' and 'arg' into global registers which
 659          * will not be modified by the parent.
 660          */
 661         __asm__ __volatile__("mov %4, %%g2\n\t"    /* Save FN into global */
 662                              "mov %5, %%g3\n\t"    /* Save ARG into global */
 663                              "mov %1, %%g1\n\t"    /* Clone syscall nr. */
 664                              "mov %2, %%o0\n\t"    /* Clone flags. */
 665                              "mov 0, %%o1\n\t"     /* usp arg == 0 */
 666                              "t 0x6d\n\t"          /* Linux/Sparc clone(). */
 667                              "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
 668                              " mov %%o0, %0\n\t"
 669                              "jmpl %%g2, %%o7\n\t"   /* Call the function. */
 670                              " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
 671                              "mov %3, %%g1\n\t"
 672                              "t 0x6d\n\t"          /* Linux/Sparc exit(). */
 673                              /* Notreached by child. */
 674                              "1:" :
 675                              "=r" (retval) :
 676                              "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
 677                              "i" (__NR_exit),  "r" (fn), "r" (arg) :
 678                              "g1", "g2", "g3", "o0", "o1", "memory", "cc");
 679         return retval;
 680 }
 681
 682 typedef struct {
 683         union {
 684                 unsigned int    pr_regs[32];
 685                 unsigned long   pr_dregs[16];
 686         } pr_fr;
 687         unsigned int __unused;
 688         unsigned int    pr_fsr;
 689         unsigned char   pr_qcnt;
 690         unsigned char   pr_q_entrysize;
 691         unsigned char   pr_en;
 692         unsigned int    pr_q[64];
 693 } elf_fpregset_t32;
 694
 695 /*
 696  * fill in the fpu structure for a core dump.
 697  */
 698 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 699 {
 700         unsigned long *kfpregs = current_thread_info()->fpregs;
 701         unsigned long fprs = current_thread_info()->fpsaved[0];
 702
 703         if (test_thread_flag(TIF_32BIT)) {
 704                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 705
 706                 if (fprs & FPRS_DL)
 707                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 708                                sizeof(unsigned int) * 32);
 709                 else
 710                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 711                                sizeof(unsigned int) * 32);
 712                 fpregs32->pr_qcnt = 0;
 713                 fpregs32->pr_q_entrysize = 8;
 714                 memset(&fpregs32->pr_q[0], 0,
 715                        (sizeof(unsigned int) * 64));
 716                 if (fprs & FPRS_FEF) {
 717                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 718                         fpregs32->pr_en = 1;
 719                 } else {
 720                         fpregs32->pr_fsr = 0;
 721                         fpregs32->pr_en = 0;
 722                 }
 723         } else {
 724                 if(fprs & FPRS_DL)
 725                         memcpy(&fpregs->pr_regs[0], kfpregs,
 726                                sizeof(unsigned int) * 32);
 727                 else
 728                         memset(&fpregs->pr_regs[0], 0,
 729                                sizeof(unsigned int) * 32);
 730                 if(fprs & FPRS_DU)
 731                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 732                                sizeof(unsigned int) * 32);
 733                 else
 734                         memset(&fpregs->pr_regs[16], 0,
 735                                sizeof(unsigned int) * 32);
 736                 if(fprs & FPRS_FEF) {
 737                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 738                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 739                 } else {
 740                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 741                 }
 742                 fpregs->pr_fprs = fprs;
 743         }
 744         return 1;
 745 }
 746
 747 /*
 748  * sparc_execve() executes a new program after the asm stub has set
 749  * things up for us.  This should basically do what I want it to.
 750  */
 751 asmlinkage int sparc_execve(struct pt_regs *regs)
 752 {
 753         int error, base = 0;
 754         char *filename;
 755
 756         /* User register window flush is done by entry.S */
 757
 758         /* Check for indirect call. */
 759         if (regs->u_regs[UREG_G1] == 0)
 760                 base = 1;
 761
 762         filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
 763         error = PTR_ERR(filename);
 764         if (IS_ERR(filename))
 765                 goto out;
 766         error = do_execve(filename,
 767                           (char __user * __user *)
 768                           regs->u_regs[base + UREG_I1],
 769                           (char __user * __user *)
 770                           regs->u_regs[base + UREG_I2], regs);
 771         putname(filename);
 772         if (!error) {
 773                 fprs_write(0);
 774                 current_thread_info()->xfsr[0] = 0;
 775                 current_thread_info()->fpsaved[0] = 0;
 776                 regs->tstate &= ~TSTATE_PEF;
 777         }
 778 out:
 779         return error;
 780 }
 781
 782 unsigned long get_wchan(struct task_struct *task)
 783 {
 784         unsigned long pc, fp, bias = 0;
 785         struct thread_info *tp;
 786         struct reg_window *rw;
 787         unsigned long ret = 0;
 788         int count = 0;
 789
 790         if (!task || task == current ||
 791             task->state == TASK_RUNNING)
 792                 goto out;
 793
 794         tp = task_thread_info(task);
 795         bias = STACK_BIAS;
 796         fp = task_thread_info(task)->ksp + bias;
 797
 798         do {
 799                 if (!kstack_valid(tp, fp))
 800                         break;
 801                 rw = (struct reg_window *) fp;
 802                 pc = rw->ins[7];
 803                 if (!in_sched_functions(pc)) {
 804                         ret = pc;
 805                         goto out;
 806                 }
 807                 fp = rw->ins[6] + bias;
 808         } while (++count < 16);
 809
 810 out:
 811         return ret;
 812 }