arch/sparc/kernel/process_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*  arch/sparc64/kernel/process.c
   3  *
   4  *  Copyright (C) 1995, 1996, 2008 David S. Miller (davem@davemloft.net)
   5  *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
   6  *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
   7  */
   8
   9 /*
  10  * This file handles the architecture-dependent parts of process handling..
  11  */
  12
  13 #include <stdarg.h>
  14
  15 #include <linux/errno.h>
  16 #include <linux/export.h>
  17 #include <linux/sched.h>
  18 #include <linux/sched/debug.h>
  19 #include <linux/sched/task.h>
  20 #include <linux/sched/task_stack.h>
  21 #include <linux/kernel.h>
  22 #include <linux/mm.h>
  23 #include <linux/fs.h>
  24 #include <linux/smp.h>
  25 #include <linux/stddef.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/slab.h>
  28 #include <linux/user.h>
  29 #include <linux/delay.h>
  30 #include <linux/compat.h>
  31 #include <linux/tick.h>
  32 #include <linux/init.h>
  33 #include <linux/cpu.h>
  34 #include <linux/perf_event.h>
  35 #include <linux/elfcore.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/nmi.h>
  38 #include <linux/context_tracking.h>
  39 #include <linux/signal.h>
  40
  41 #include <linux/uaccess.h>
  42 #include <asm/page.h>
  43 #include <asm/pgalloc.h>
  44 #include <asm/pgtable.h>
  45 #include <asm/processor.h>
  46 #include <asm/pstate.h>
  47 #include <asm/elf.h>
  48 #include <asm/fpumacro.h>
  49 #include <asm/head.h>
  50 #include <asm/cpudata.h>
  51 #include <asm/mmu_context.h>
  52 #include <asm/unistd.h>
  53 #include <asm/hypervisor.h>
  54 #include <asm/syscalls.h>
  55 #include <asm/irq_regs.h>
  56 #include <asm/smp.h>
  57 #include <asm/pcr.h>
  58
  59 #include "kstack.h"
  60
  61 /* Idle loop support on sparc64. */
  62 void arch_cpu_idle(void)
  63 {
  64         if (tlb_type != hypervisor) {
  65                 touch_nmi_watchdog();
  66                 local_irq_enable();
  67         } else {
  68                 unsigned long pstate;
  69
  70                 local_irq_enable();
  71
  72                 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
  73                  * the cpu sleep hypervisor call.
  74                  */
  75                 __asm__ __volatile__(
  76                         "rdpr %%pstate, %0\n\t"
  77                         "andn %0, %1, %0\n\t"
  78                         "wrpr %0, %%g0, %%pstate"
  79                         : "=&r" (pstate)
  80                         : "i" (PSTATE_IE));
  81
  82                 if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
  83                         sun4v_cpu_yield();
  84                         /* If resumed by cpu_poke then we need to explicitly
  85                          * call scheduler_ipi().
  86                          */
  87                         scheduler_poke();
  88                 }
  89
  90                 /* Re-enable interrupts. */
  91                 __asm__ __volatile__(
  92                         "rdpr %%pstate, %0\n\t"
  93                         "or %0, %1, %0\n\t"
  94                         "wrpr %0, %%g0, %%pstate"
  95                         : "=&r" (pstate)
  96                         : "i" (PSTATE_IE));
  97         }
  98 }
  99
 100 #ifdef CONFIG_HOTPLUG_CPU
 101 void arch_cpu_idle_dead(void)
 102 {
 103         sched_preempt_enable_no_resched();
 104         cpu_play_dead();
 105 }
 106 #endif
 107
 108 #ifdef CONFIG_COMPAT
 109 static void show_regwindow32(struct pt_regs *regs)
 110 {
 111         struct reg_window32 __user *rw;
 112         struct reg_window32 r_w;
 113         mm_segment_t old_fs;
 114
 115         __asm__ __volatile__ ("flushw");
 116         rw = compat_ptr((unsigned int)regs->u_regs[14]);
 117         old_fs = get_fs();
 118         set_fs (USER_DS);
 119         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 120                 set_fs (old_fs);
 121                 return;
 122         }
 123
 124         set_fs (old_fs);
 125         printk("l0: %08x l1: %08x l2: %08x l3: %08x "
 126                "l4: %08x l5: %08x l6: %08x l7: %08x\n",
 127                r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
 128                r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
 129         printk("i0: %08x i1: %08x i2: %08x i3: %08x "
 130                "i4: %08x i5: %08x i6: %08x i7: %08x\n",
 131                r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
 132                r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
 133 }
 134 #else
 135 #define show_regwindow32(regs)  do { } while (0)
 136 #endif
 137
 138 static void show_regwindow(struct pt_regs *regs)
 139 {
 140         struct reg_window __user *rw;
 141         struct reg_window *rwk;
 142         struct reg_window r_w;
 143         mm_segment_t old_fs;
 144
 145         if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
 146                 __asm__ __volatile__ ("flushw");
 147                 rw = (struct reg_window __user *)
 148                         (regs->u_regs[14] + STACK_BIAS);
 149                 rwk = (struct reg_window *)
 150                         (regs->u_regs[14] + STACK_BIAS);
 151                 if (!(regs->tstate & TSTATE_PRIV)) {
 152                         old_fs = get_fs();
 153                         set_fs (USER_DS);
 154                         if (copy_from_user (&r_w, rw, sizeof(r_w))) {
 155                                 set_fs (old_fs);
 156                                 return;
 157                         }
 158                         rwk = &r_w;
 159                         set_fs (old_fs);
 160                 }
 161         } else {
 162                 show_regwindow32(regs);
 163                 return;
 164         }
 165         printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
 166                rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
 167         printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
 168                rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
 169         printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
 170                rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
 171         printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
 172                rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
 173         if (regs->tstate & TSTATE_PRIV)
 174                 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
 175 }
 176
 177 void show_regs(struct pt_regs *regs)
 178 {
 179         show_regs_print_info(KERN_DEFAULT);
 180
 181         printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
 182                regs->tpc, regs->tnpc, regs->y, print_tainted());
 183         printk("TPC: <%pS>\n", (void *) regs->tpc);
 184         printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
 185                regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
 186                regs->u_regs[3]);
 187         printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
 188                regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
 189                regs->u_regs[7]);
 190         printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
 191                regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
 192                regs->u_regs[11]);
 193         printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
 194                regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
 195                regs->u_regs[15]);
 196         printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
 197         show_regwindow(regs);
 198         show_stack(current, (unsigned long *) regs->u_regs[UREG_FP]);
 199 }
 200
 201 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
 202 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
 203
 204 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
 205                               int this_cpu)
 206 {
 207         struct global_reg_snapshot *rp;
 208
 209         flushw_all();
 210
 211         rp = &global_cpu_snapshot[this_cpu].reg;
 212
 213         rp->tstate = regs->tstate;
 214         rp->tpc = regs->tpc;
 215         rp->tnpc = regs->tnpc;
 216         rp->o7 = regs->u_regs[UREG_I7];
 217
 218         if (regs->tstate & TSTATE_PRIV) {
 219                 struct reg_window *rw;
 220
 221                 rw = (struct reg_window *)
 222                         (regs->u_regs[UREG_FP] + STACK_BIAS);
 223                 if (kstack_valid(tp, (unsigned long) rw)) {
 224                         rp->i7 = rw->ins[7];
 225                         rw = (struct reg_window *)
 226                                 (rw->ins[6] + STACK_BIAS);
 227                         if (kstack_valid(tp, (unsigned long) rw))
 228                                 rp->rpc = rw->ins[7];
 229                 }
 230         } else {
 231                 rp->i7 = 0;
 232                 rp->rpc = 0;
 233         }
 234         rp->thread = tp;
 235 }
 236
 237 /* In order to avoid hangs we do not try to synchronize with the
 238  * global register dump client cpus.  The last store they make is to
 239  * the thread pointer, so do a short poll waiting for that to become
 240  * non-NULL.
 241  */
 242 static void __global_reg_poll(struct global_reg_snapshot *gp)
 243 {
 244         int limit = 0;
 245
 246         while (!gp->thread && ++limit < 100) {
 247                 barrier();
 248                 udelay(1);
 249         }
 250 }
 251
 252 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 253 {
 254         struct thread_info *tp = current_thread_info();
 255         struct pt_regs *regs = get_irq_regs();
 256         unsigned long flags;
 257         int this_cpu, cpu;
 258
 259         if (!regs)
 260                 regs = tp->kregs;
 261
 262         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 263
 264         this_cpu = raw_smp_processor_id();
 265
 266         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 267
 268         if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
 269                 __global_reg_self(tp, regs, this_cpu);
 270
 271         smp_fetch_global_regs();
 272
 273         for_each_cpu(cpu, mask) {
 274                 struct global_reg_snapshot *gp;
 275
 276                 if (exclude_self && cpu == this_cpu)
 277                         continue;
 278
 279                 gp = &global_cpu_snapshot[cpu].reg;
 280
 281                 __global_reg_poll(gp);
 282
 283                 tp = gp->thread;
 284                 printk("%c CPU[%3d]: TSTATE[%016lx] TPC[%016lx] TNPC[%016lx] TASK[%s:%d]\n",
 285                        (cpu == this_cpu ? '*' : ' '), cpu,
 286                        gp->tstate, gp->tpc, gp->tnpc,
 287                        ((tp && tp->task) ? tp->task->comm : "NULL"),
 288                        ((tp && tp->task) ? tp->task->pid : -1));
 289
 290                 if (gp->tstate & TSTATE_PRIV) {
 291                         printk("             TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
 292                                (void *) gp->tpc,
 293                                (void *) gp->o7,
 294                                (void *) gp->i7,
 295                                (void *) gp->rpc);
 296                 } else {
 297                         printk("             TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
 298                                gp->tpc, gp->o7, gp->i7, gp->rpc);
 299                 }
 300
 301                 touch_nmi_watchdog();
 302         }
 303
 304         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 305
 306         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 307 }
 308
 309 #ifdef CONFIG_MAGIC_SYSRQ
 310
 311 static void sysrq_handle_globreg(int key)
 312 {
 313         trigger_all_cpu_backtrace();
 314 }
 315
 316 static struct sysrq_key_op sparc_globalreg_op = {
 317         .handler        = sysrq_handle_globreg,
 318         .help_msg       = "global-regs(y)",
 319         .action_msg     = "Show Global CPU Regs",
 320 };
 321
 322 static void __global_pmu_self(int this_cpu)
 323 {
 324         struct global_pmu_snapshot *pp;
 325         int i, num;
 326
 327         if (!pcr_ops)
 328                 return;
 329
 330         pp = &global_cpu_snapshot[this_cpu].pmu;
 331
 332         num = 1;
 333         if (tlb_type == hypervisor &&
 334             sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
 335                 num = 4;
 336
 337         for (i = 0; i < num; i++) {
 338                 pp->pcr[i] = pcr_ops->read_pcr(i);
 339                 pp->pic[i] = pcr_ops->read_pic(i);
 340         }
 341 }
 342
 343 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
 344 {
 345         int limit = 0;
 346
 347         while (!pp->pcr[0] && ++limit < 100) {
 348                 barrier();
 349                 udelay(1);
 350         }
 351 }
 352
 353 static void pmu_snapshot_all_cpus(void)
 354 {
 355         unsigned long flags;
 356         int this_cpu, cpu;
 357
 358         spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
 359
 360         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 361
 362         this_cpu = raw_smp_processor_id();
 363
 364         __global_pmu_self(this_cpu);
 365
 366         smp_fetch_global_pmu();
 367
 368         for_each_online_cpu(cpu) {
 369                 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
 370
 371                 __global_pmu_poll(pp);
 372
 373                 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
 374                        (cpu == this_cpu ? '*' : ' '), cpu,
 375                        pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
 376                        pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
 377
 378                 touch_nmi_watchdog();
 379         }
 380
 381         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 382
 383         spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
 384 }
 385
 386 static void sysrq_handle_globpmu(int key)
 387 {
 388         pmu_snapshot_all_cpus();
 389 }
 390
 391 static struct sysrq_key_op sparc_globalpmu_op = {
 392         .handler        = sysrq_handle_globpmu,
 393         .help_msg       = "global-pmu(x)",
 394         .action_msg     = "Show Global PMU Regs",
 395 };
 396
 397 static int __init sparc_sysrq_init(void)
 398 {
 399         int ret = register_sysrq_key('y', &sparc_globalreg_op);
 400
 401         if (!ret)
 402                 ret = register_sysrq_key('x', &sparc_globalpmu_op);
 403         return ret;
 404 }
 405
 406 core_initcall(sparc_sysrq_init);
 407
 408 #endif
 409
 410 /* Free current thread data structures etc.. */
 411 void exit_thread(struct task_struct *tsk)
 412 {
 413         struct thread_info *t = task_thread_info(tsk);
 414
 415         if (t->utraps) {
 416                 if (t->utraps[0] < 2)
 417                         kfree (t->utraps);
 418                 else
 419                         t->utraps[0]--;
 420         }
 421 }
 422
 423 void flush_thread(void)
 424 {
 425         struct thread_info *t = current_thread_info();
 426         struct mm_struct *mm;
 427
 428         mm = t->task->mm;
 429         if (mm)
 430                 tsb_context_switch(mm);
 431
 432         set_thread_wsaved(0);
 433
 434         /* Clear FPU register state. */
 435         t->fpsaved[0] = 0;
 436 }
 437
 438 /* It's a bit more tricky when 64-bit tasks are involved... */
 439 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
 440 {
 441         bool stack_64bit = test_thread_64bit_stack(psp);
 442         unsigned long fp, distance, rval;
 443
 444         if (stack_64bit) {
 445                 csp += STACK_BIAS;
 446                 psp += STACK_BIAS;
 447                 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
 448                 fp += STACK_BIAS;
 449                 if (test_thread_flag(TIF_32BIT))
 450                         fp &= 0xffffffff;
 451         } else
 452                 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
 453
 454         /* Now align the stack as this is mandatory in the Sparc ABI
 455          * due to how register windows work.  This hides the
 456          * restriction from thread libraries etc.
 457          */
 458         csp &= ~15UL;
 459
 460         distance = fp - psp;
 461         rval = (csp - distance);
 462         if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
 463                 rval = 0;
 464         else if (!stack_64bit) {
 465                 if (put_user(((u32)csp),
 466                              &(((struct reg_window32 __user *)rval)->ins[6])))
 467                         rval = 0;
 468         } else {
 469                 if (put_user(((u64)csp - STACK_BIAS),
 470                              &(((struct reg_window __user *)rval)->ins[6])))
 471                         rval = 0;
 472                 else
 473                         rval = rval - STACK_BIAS;
 474         }
 475
 476         return rval;
 477 }
 478
 479 /* Standard stuff. */
 480 static inline void shift_window_buffer(int first_win, int last_win,
 481                                        struct thread_info *t)
 482 {
 483         int i;
 484
 485         for (i = first_win; i < last_win; i++) {
 486                 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
 487                 memcpy(&t->reg_window[i], &t->reg_window[i+1],
 488                        sizeof(struct reg_window));
 489         }
 490 }
 491
 492 void synchronize_user_stack(void)
 493 {
 494         struct thread_info *t = current_thread_info();
 495         unsigned long window;
 496
 497         flush_user_windows();
 498         if ((window = get_thread_wsaved()) != 0) {
 499                 window -= 1;
 500                 do {
 501                         struct reg_window *rwin = &t->reg_window[window];
 502                         int winsize = sizeof(struct reg_window);
 503                         unsigned long sp;
 504
 505                         sp = t->rwbuf_stkptrs[window];
 506
 507                         if (test_thread_64bit_stack(sp))
 508                                 sp += STACK_BIAS;
 509                         else
 510                                 winsize = sizeof(struct reg_window32);
 511
 512                         if (!copy_to_user((char __user *)sp, rwin, winsize)) {
 513                                 shift_window_buffer(window, get_thread_wsaved() - 1, t);
 514                                 set_thread_wsaved(get_thread_wsaved() - 1);
 515                         }
 516                 } while (window--);
 517         }
 518 }
 519
 520 static void stack_unaligned(unsigned long sp)
 521 {
 522         force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp, 0, current);
 523 }
 524
 525 static const char uwfault32[] = KERN_INFO \
 526         "%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
 527 static const char uwfault64[] = KERN_INFO \
 528         "%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
 529
 530 void fault_in_user_windows(struct pt_regs *regs)
 531 {
 532         struct thread_info *t = current_thread_info();
 533         unsigned long window;
 534
 535         flush_user_windows();
 536         window = get_thread_wsaved();
 537
 538         if (likely(window != 0)) {
 539                 window -= 1;
 540                 do {
 541                         struct reg_window *rwin = &t->reg_window[window];
 542                         int winsize = sizeof(struct reg_window);
 543                         unsigned long sp, orig_sp;
 544
 545                         orig_sp = sp = t->rwbuf_stkptrs[window];
 546
 547                         if (test_thread_64bit_stack(sp))
 548                                 sp += STACK_BIAS;
 549                         else
 550                                 winsize = sizeof(struct reg_window32);
 551
 552                         if (unlikely(sp & 0x7UL))
 553                                 stack_unaligned(sp);
 554
 555                         if (unlikely(copy_to_user((char __user *)sp,
 556                                                   rwin, winsize))) {
 557                                 if (show_unhandled_signals)
 558                                         printk_ratelimited(is_compat_task() ?
 559                                                            uwfault32 : uwfault64,
 560                                                            current->comm, current->pid,
 561                                                            sp, orig_sp,
 562                                                            regs->tpc,
 563                                                            regs->u_regs[UREG_I7]);
 564                                 goto barf;
 565                         }
 566                 } while (window--);
 567         }
 568         set_thread_wsaved(0);
 569         return;
 570
 571 barf:
 572         set_thread_wsaved(window + 1);
 573         force_sig(SIGSEGV, current);
 574 }
 575
 576 asmlinkage long sparc_do_fork(unsigned long clone_flags,
 577                               unsigned long stack_start,
 578                               struct pt_regs *regs,
 579                               unsigned long stack_size)
 580 {
 581         int __user *parent_tid_ptr, *child_tid_ptr;
 582         unsigned long orig_i1 = regs->u_regs[UREG_I1];
 583         long ret;
 584
 585 #ifdef CONFIG_COMPAT
 586         if (test_thread_flag(TIF_32BIT)) {
 587                 parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
 588                 child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
 589         } else
 590 #endif
 591         {
 592                 parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
 593                 child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 594         }
 595
 596         ret = do_fork(clone_flags, stack_start, stack_size,
 597                       parent_tid_ptr, child_tid_ptr);
 598
 599         /* If we get an error and potentially restart the system
 600          * call, we're screwed because copy_thread() clobbered
 601          * the parent's %o1.  So detect that case and restore it
 602          * here.
 603          */
 604         if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
 605                 regs->u_regs[UREG_I1] = orig_i1;
 606
 607         return ret;
 608 }
 609
 610 /* Copy a Sparc thread.  The fork() return value conventions
 611  * under SunOS are nothing short of bletcherous:
 612  * Parent -->  %o0 == childs  pid, %o1 == 0
 613  * Child  -->  %o0 == parents pid, %o1 == 1
 614  */
 615 int copy_thread(unsigned long clone_flags, unsigned long sp,
 616                 unsigned long arg, struct task_struct *p)
 617 {
 618         struct thread_info *t = task_thread_info(p);
 619         struct pt_regs *regs = current_pt_regs();
 620         struct sparc_stackf *parent_sf;
 621         unsigned long child_stack_sz;
 622         char *child_trap_frame;
 623
 624         /* Calculate offset to stack_frame & pt_regs */
 625         child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
 626         child_trap_frame = (task_stack_page(p) +
 627                             (THREAD_SIZE - child_stack_sz));
 628
 629         t->new_child = 1;
 630         t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 631         t->kregs = (struct pt_regs *) (child_trap_frame +
 632                                        sizeof(struct sparc_stackf));
 633         t->fpsaved[0] = 0;
 634
 635         if (unlikely(p->flags & PF_KTHREAD)) {
 636                 memset(child_trap_frame, 0, child_stack_sz);
 637                 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
 638                         (current_pt_regs()->tstate + 1) & TSTATE_CWP;
 639                 t->current_ds = ASI_P;
 640                 t->kregs->u_regs[UREG_G1] = sp; /* function */
 641                 t->kregs->u_regs[UREG_G2] = arg;
 642                 return 0;
 643         }
 644
 645         parent_sf = ((struct sparc_stackf *) regs) - 1;
 646         memcpy(child_trap_frame, parent_sf, child_stack_sz);
 647         if (t->flags & _TIF_32BIT) {
 648                 sp &= 0x00000000ffffffffUL;
 649                 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 650         }
 651         t->kregs->u_regs[UREG_FP] = sp;
 652         __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
 653                 (regs->tstate + 1) & TSTATE_CWP;
 654         t->current_ds = ASI_AIUS;
 655         if (sp != regs->u_regs[UREG_FP]) {
 656                 unsigned long csp;
 657
 658                 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
 659                 if (!csp)
 660                         return -EFAULT;
 661                 t->kregs->u_regs[UREG_FP] = csp;
 662         }
 663         if (t->utraps)
 664                 t->utraps[0]++;
 665
 666         /* Set the return value for the child. */
 667         t->kregs->u_regs[UREG_I0] = current->pid;
 668         t->kregs->u_regs[UREG_I1] = 1;
 669
 670         /* Set the second return value for the parent. */
 671         regs->u_regs[UREG_I1] = 0;
 672
 673         if (clone_flags & CLONE_SETTLS)
 674                 t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
 675
 676         return 0;
 677 }
 678
 679 /* TIF_MCDPER in thread info flags for current task is updated lazily upon
 680  * a context switch. Update this flag in current task's thread flags
 681  * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
 682  */
 683 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 684 {
 685         if (adi_capable()) {
 686                 register unsigned long tmp_mcdper;
 687
 688                 __asm__ __volatile__(
 689                         ".word 0x83438000\n\t"  /* rd  %mcdper, %g1 */
 690                         "mov %%g1, %0\n\t"
 691                         : "=r" (tmp_mcdper)
 692                         :
 693                         : "g1");
 694                 if (tmp_mcdper)
 695                         set_thread_flag(TIF_MCDPER);
 696                 else
 697                         clear_thread_flag(TIF_MCDPER);
 698         }
 699
 700         *dst = *src;
 701         return 0;
 702 }
 703
 704 typedef struct {
 705         union {
 706                 unsigned int    pr_regs[32];
 707                 unsigned long   pr_dregs[16];
 708         } pr_fr;
 709         unsigned int __unused;
 710         unsigned int    pr_fsr;
 711         unsigned char   pr_qcnt;
 712         unsigned char   pr_q_entrysize;
 713         unsigned char   pr_en;
 714         unsigned int    pr_q[64];
 715 } elf_fpregset_t32;
 716
 717 /*
 718  * fill in the fpu structure for a core dump.
 719  */
 720 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 721 {
 722         unsigned long *kfpregs = current_thread_info()->fpregs;
 723         unsigned long fprs = current_thread_info()->fpsaved[0];
 724
 725         if (test_thread_flag(TIF_32BIT)) {
 726                 elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;
 727
 728                 if (fprs & FPRS_DL)
 729                         memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
 730                                sizeof(unsigned int) * 32);
 731                 else
 732                         memset(&fpregs32->pr_fr.pr_regs[0], 0,
 733                                sizeof(unsigned int) * 32);
 734                 fpregs32->pr_qcnt = 0;
 735                 fpregs32->pr_q_entrysize = 8;
 736                 memset(&fpregs32->pr_q[0], 0,
 737                        (sizeof(unsigned int) * 64));
 738                 if (fprs & FPRS_FEF) {
 739                         fpregs32->pr_fsr = (unsigned int) current_thread_info()->xfsr[0];
 740                         fpregs32->pr_en = 1;
 741                 } else {
 742                         fpregs32->pr_fsr = 0;
 743                         fpregs32->pr_en = 0;
 744                 }
 745         } else {
 746                 if(fprs & FPRS_DL)
 747                         memcpy(&fpregs->pr_regs[0], kfpregs,
 748                                sizeof(unsigned int) * 32);
 749                 else
 750                         memset(&fpregs->pr_regs[0], 0,
 751                                sizeof(unsigned int) * 32);
 752                 if(fprs & FPRS_DU)
 753                         memcpy(&fpregs->pr_regs[16], kfpregs+16,
 754                                sizeof(unsigned int) * 32);
 755                 else
 756                         memset(&fpregs->pr_regs[16], 0,
 757                                sizeof(unsigned int) * 32);
 758                 if(fprs & FPRS_FEF) {
 759                         fpregs->pr_fsr = current_thread_info()->xfsr[0];
 760                         fpregs->pr_gsr = current_thread_info()->gsr[0];
 761                 } else {
 762                         fpregs->pr_fsr = fpregs->pr_gsr = 0;
 763                 }
 764                 fpregs->pr_fprs = fprs;
 765         }
 766         return 1;
 767 }
 768 EXPORT_SYMBOL(dump_fpu);
 769
 770 unsigned long get_wchan(struct task_struct *task)
 771 {
 772         unsigned long pc, fp, bias = 0;
 773         struct thread_info *tp;
 774         struct reg_window *rw;
 775         unsigned long ret = 0;
 776         int count = 0;
 777
 778         if (!task || task == current ||
 779             task->state == TASK_RUNNING)
 780                 goto out;
 781
 782         tp = task_thread_info(task);
 783         bias = STACK_BIAS;
 784         fp = task_thread_info(task)->ksp + bias;
 785
 786         do {
 787                 if (!kstack_valid(tp, fp))
 788                         break;
 789                 rw = (struct reg_window *) fp;
 790                 pc = rw->ins[7];
 791                 if (!in_sched_functions(pc)) {
 792                         ret = pc;
 793                         goto out;
 794                 }
 795                 fp = rw->ins[6] + bias;
 796         } while (++count < 16);
 797
 798 out:
 799         return ret;
 800 }