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