1 // SPDX-License-Identifier: GPL-2.0
2 /* arch/sparc64/kernel/process.c
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)
10 * This file handles the architecture-dependent parts of process handling..
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>
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>
41 #include <linux/uaccess.h>
43 #include <asm/pgalloc.h>
44 #include <asm/processor.h>
45 #include <asm/pstate.h>
47 #include <asm/fpumacro.h>
49 #include <asm/cpudata.h>
50 #include <asm/mmu_context.h>
51 #include <asm/unistd.h>
52 #include <asm/hypervisor.h>
53 #include <asm/syscalls.h>
54 #include <asm/irq_regs.h>
60 /* Idle loop support on sparc64. */
61 void arch_cpu_idle(void)
63 if (tlb_type != hypervisor) {
65 raw_local_irq_enable();
69 raw_local_irq_enable();
71 /* The sun4v sleeping code requires that we have PSTATE.IE cleared over
72 * the cpu sleep hypervisor call.
75 "rdpr %%pstate, %0\n\t"
77 "wrpr %0, %%g0, %%pstate"
81 if (!need_resched() && !cpu_is_offline(smp_processor_id())) {
83 /* If resumed by cpu_poke then we need to explicitly
84 * call scheduler_ipi().
89 /* Re-enable interrupts. */
91 "rdpr %%pstate, %0\n\t"
93 "wrpr %0, %%g0, %%pstate"
99 #ifdef CONFIG_HOTPLUG_CPU
100 void arch_cpu_idle_dead(void)
102 sched_preempt_enable_no_resched();
108 static void show_regwindow32(struct pt_regs *regs)
110 struct reg_window32 __user *rw;
111 struct reg_window32 r_w;
114 __asm__ __volatile__ ("flushw");
115 rw = compat_ptr((unsigned int)regs->u_regs[14]);
118 if (copy_from_user (&r_w, rw, sizeof(r_w))) {
124 printk("l0: %08x l1: %08x l2: %08x l3: %08x "
125 "l4: %08x l5: %08x l6: %08x l7: %08x\n",
126 r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
127 r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
128 printk("i0: %08x i1: %08x i2: %08x i3: %08x "
129 "i4: %08x i5: %08x i6: %08x i7: %08x\n",
130 r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
131 r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
134 #define show_regwindow32(regs) do { } while (0)
137 static void show_regwindow(struct pt_regs *regs)
139 struct reg_window __user *rw;
140 struct reg_window *rwk;
141 struct reg_window r_w;
144 if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
145 __asm__ __volatile__ ("flushw");
146 rw = (struct reg_window __user *)
147 (regs->u_regs[14] + STACK_BIAS);
148 rwk = (struct reg_window *)
149 (regs->u_regs[14] + STACK_BIAS);
150 if (!(regs->tstate & TSTATE_PRIV)) {
153 if (copy_from_user (&r_w, rw, sizeof(r_w))) {
161 show_regwindow32(regs);
164 printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
165 rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
166 printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
167 rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
168 printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
169 rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
170 printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
171 rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
172 if (regs->tstate & TSTATE_PRIV)
173 printk("I7: <%pS>\n", (void *) rwk->ins[7]);
176 void show_regs(struct pt_regs *regs)
178 show_regs_print_info(KERN_DEFAULT);
180 printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x %s\n", regs->tstate,
181 regs->tpc, regs->tnpc, regs->y, print_tainted());
182 printk("TPC: <%pS>\n", (void *) regs->tpc);
183 printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
184 regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
186 printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
187 regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
189 printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
190 regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
192 printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
193 regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
195 printk("RPC: <%pS>\n", (void *) regs->u_regs[15]);
196 show_regwindow(regs);
197 show_stack(current, (unsigned long *)regs->u_regs[UREG_FP], KERN_DEFAULT);
200 union global_cpu_snapshot global_cpu_snapshot[NR_CPUS];
201 static DEFINE_SPINLOCK(global_cpu_snapshot_lock);
203 static void __global_reg_self(struct thread_info *tp, struct pt_regs *regs,
206 struct global_reg_snapshot *rp;
210 rp = &global_cpu_snapshot[this_cpu].reg;
212 rp->tstate = regs->tstate;
214 rp->tnpc = regs->tnpc;
215 rp->o7 = regs->u_regs[UREG_I7];
217 if (regs->tstate & TSTATE_PRIV) {
218 struct reg_window *rw;
220 rw = (struct reg_window *)
221 (regs->u_regs[UREG_FP] + STACK_BIAS);
222 if (kstack_valid(tp, (unsigned long) rw)) {
224 rw = (struct reg_window *)
225 (rw->ins[6] + STACK_BIAS);
226 if (kstack_valid(tp, (unsigned long) rw))
227 rp->rpc = rw->ins[7];
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
241 static void __global_reg_poll(struct global_reg_snapshot *gp)
245 while (!gp->thread && ++limit < 100) {
251 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
253 struct thread_info *tp = current_thread_info();
254 struct pt_regs *regs = get_irq_regs();
261 spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
263 this_cpu = raw_smp_processor_id();
265 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
267 if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
268 __global_reg_self(tp, regs, this_cpu);
270 smp_fetch_global_regs();
272 for_each_cpu(cpu, mask) {
273 struct global_reg_snapshot *gp;
275 if (exclude_self && cpu == this_cpu)
278 gp = &global_cpu_snapshot[cpu].reg;
280 __global_reg_poll(gp);
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));
289 if (gp->tstate & TSTATE_PRIV) {
290 printk(" TPC[%pS] O7[%pS] I7[%pS] RPC[%pS]\n",
296 printk(" TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
297 gp->tpc, gp->o7, gp->i7, gp->rpc);
300 touch_nmi_watchdog();
303 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
305 spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
308 #ifdef CONFIG_MAGIC_SYSRQ
310 static void sysrq_handle_globreg(int key)
312 trigger_all_cpu_backtrace();
315 static const struct sysrq_key_op sparc_globalreg_op = {
316 .handler = sysrq_handle_globreg,
317 .help_msg = "global-regs(y)",
318 .action_msg = "Show Global CPU Regs",
321 static void __global_pmu_self(int this_cpu)
323 struct global_pmu_snapshot *pp;
329 pp = &global_cpu_snapshot[this_cpu].pmu;
332 if (tlb_type == hypervisor &&
333 sun4v_chip_type >= SUN4V_CHIP_NIAGARA4)
336 for (i = 0; i < num; i++) {
337 pp->pcr[i] = pcr_ops->read_pcr(i);
338 pp->pic[i] = pcr_ops->read_pic(i);
342 static void __global_pmu_poll(struct global_pmu_snapshot *pp)
346 while (!pp->pcr[0] && ++limit < 100) {
352 static void pmu_snapshot_all_cpus(void)
357 spin_lock_irqsave(&global_cpu_snapshot_lock, flags);
359 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
361 this_cpu = raw_smp_processor_id();
363 __global_pmu_self(this_cpu);
365 smp_fetch_global_pmu();
367 for_each_online_cpu(cpu) {
368 struct global_pmu_snapshot *pp = &global_cpu_snapshot[cpu].pmu;
370 __global_pmu_poll(pp);
372 printk("%c CPU[%3d]: PCR[%08lx:%08lx:%08lx:%08lx] PIC[%08lx:%08lx:%08lx:%08lx]\n",
373 (cpu == this_cpu ? '*' : ' '), cpu,
374 pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
375 pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
377 touch_nmi_watchdog();
380 memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
382 spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
385 static void sysrq_handle_globpmu(int key)
387 pmu_snapshot_all_cpus();
390 static const struct sysrq_key_op sparc_globalpmu_op = {
391 .handler = sysrq_handle_globpmu,
392 .help_msg = "global-pmu(x)",
393 .action_msg = "Show Global PMU Regs",
396 static int __init sparc_sysrq_init(void)
398 int ret = register_sysrq_key('y', &sparc_globalreg_op);
401 ret = register_sysrq_key('x', &sparc_globalpmu_op);
405 core_initcall(sparc_sysrq_init);
409 /* Free current thread data structures etc.. */
410 void exit_thread(struct task_struct *tsk)
412 struct thread_info *t = task_thread_info(tsk);
415 if (t->utraps[0] < 2)
422 void flush_thread(void)
424 struct thread_info *t = current_thread_info();
425 struct mm_struct *mm;
429 tsb_context_switch(mm);
431 set_thread_wsaved(0);
433 /* Clear FPU register state. */
437 /* It's a bit more tricky when 64-bit tasks are involved... */
438 static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
440 bool stack_64bit = test_thread_64bit_stack(psp);
441 unsigned long fp, distance, rval;
446 __get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
448 if (test_thread_flag(TIF_32BIT))
451 __get_user(fp, &(((struct reg_window32 __user *)psp)->ins[6]));
453 /* Now align the stack as this is mandatory in the Sparc ABI
454 * due to how register windows work. This hides the
455 * restriction from thread libraries etc.
460 rval = (csp - distance);
461 if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
463 else if (!stack_64bit) {
464 if (put_user(((u32)csp),
465 &(((struct reg_window32 __user *)rval)->ins[6])))
468 if (put_user(((u64)csp - STACK_BIAS),
469 &(((struct reg_window __user *)rval)->ins[6])))
472 rval = rval - STACK_BIAS;
478 /* Standard stuff. */
479 static inline void shift_window_buffer(int first_win, int last_win,
480 struct thread_info *t)
484 for (i = first_win; i < last_win; i++) {
485 t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
486 memcpy(&t->reg_window[i], &t->reg_window[i+1],
487 sizeof(struct reg_window));
491 void synchronize_user_stack(void)
493 struct thread_info *t = current_thread_info();
494 unsigned long window;
496 flush_user_windows();
497 if ((window = get_thread_wsaved()) != 0) {
500 struct reg_window *rwin = &t->reg_window[window];
501 int winsize = sizeof(struct reg_window);
504 sp = t->rwbuf_stkptrs[window];
506 if (test_thread_64bit_stack(sp))
509 winsize = sizeof(struct reg_window32);
511 if (!copy_to_user((char __user *)sp, rwin, winsize)) {
512 shift_window_buffer(window, get_thread_wsaved() - 1, t);
513 set_thread_wsaved(get_thread_wsaved() - 1);
519 static void stack_unaligned(unsigned long sp)
521 force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) sp, 0);
524 static const char uwfault32[] = KERN_INFO \
525 "%s[%d]: bad register window fault: SP %08lx (orig_sp %08lx) TPC %08lx O7 %08lx\n";
526 static const char uwfault64[] = KERN_INFO \
527 "%s[%d]: bad register window fault: SP %016lx (orig_sp %016lx) TPC %08lx O7 %016lx\n";
529 void fault_in_user_windows(struct pt_regs *regs)
531 struct thread_info *t = current_thread_info();
532 unsigned long window;
534 flush_user_windows();
535 window = get_thread_wsaved();
537 if (likely(window != 0)) {
540 struct reg_window *rwin = &t->reg_window[window];
541 int winsize = sizeof(struct reg_window);
542 unsigned long sp, orig_sp;
544 orig_sp = sp = t->rwbuf_stkptrs[window];
546 if (test_thread_64bit_stack(sp))
549 winsize = sizeof(struct reg_window32);
551 if (unlikely(sp & 0x7UL))
554 if (unlikely(copy_to_user((char __user *)sp,
556 if (show_unhandled_signals)
557 printk_ratelimited(is_compat_task() ?
558 uwfault32 : uwfault64,
559 current->comm, current->pid,
562 regs->u_regs[UREG_I7]);
567 set_thread_wsaved(0);
571 set_thread_wsaved(window + 1);
575 /* Copy a Sparc thread. The fork() return value conventions
576 * under SunOS are nothing short of bletcherous:
577 * Parent --> %o0 == childs pid, %o1 == 0
578 * Child --> %o0 == parents pid, %o1 == 1
580 int copy_thread(unsigned long clone_flags, unsigned long sp, unsigned long arg,
581 struct task_struct *p, unsigned long tls)
583 struct thread_info *t = task_thread_info(p);
584 struct pt_regs *regs = current_pt_regs();
585 struct sparc_stackf *parent_sf;
586 unsigned long child_stack_sz;
587 char *child_trap_frame;
589 /* Calculate offset to stack_frame & pt_regs */
590 child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
591 child_trap_frame = (task_stack_page(p) +
592 (THREAD_SIZE - child_stack_sz));
595 t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
596 t->kregs = (struct pt_regs *) (child_trap_frame +
597 sizeof(struct sparc_stackf));
600 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
601 memset(child_trap_frame, 0, child_stack_sz);
602 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
603 (current_pt_regs()->tstate + 1) & TSTATE_CWP;
604 t->current_ds = ASI_P;
605 t->kregs->u_regs[UREG_G1] = sp; /* function */
606 t->kregs->u_regs[UREG_G2] = arg;
610 parent_sf = ((struct sparc_stackf *) regs) - 1;
611 memcpy(child_trap_frame, parent_sf, child_stack_sz);
612 if (t->flags & _TIF_32BIT) {
613 sp &= 0x00000000ffffffffUL;
614 regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
616 t->kregs->u_regs[UREG_FP] = sp;
617 __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] =
618 (regs->tstate + 1) & TSTATE_CWP;
619 t->current_ds = ASI_AIUS;
620 if (sp != regs->u_regs[UREG_FP]) {
623 csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
626 t->kregs->u_regs[UREG_FP] = csp;
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;
635 /* Set the second return value for the parent. */
636 regs->u_regs[UREG_I1] = 0;
638 if (clone_flags & CLONE_SETTLS)
639 t->kregs->u_regs[UREG_G7] = tls;
644 /* TIF_MCDPER in thread info flags for current task is updated lazily upon
645 * a context switch. Update this flag in current task's thread flags
646 * before dup so the dup'd task will inherit the current TIF_MCDPER flag.
648 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
651 register unsigned long tmp_mcdper;
653 __asm__ __volatile__(
654 ".word 0x83438000\n\t" /* rd %mcdper, %g1 */
660 set_thread_flag(TIF_MCDPER);
662 clear_thread_flag(TIF_MCDPER);
669 unsigned long get_wchan(struct task_struct *task)
671 unsigned long pc, fp, bias = 0;
672 struct thread_info *tp;
673 struct reg_window *rw;
674 unsigned long ret = 0;
677 if (!task || task == current ||
678 task->state == TASK_RUNNING)
681 tp = task_thread_info(task);
683 fp = task_thread_info(task)->ksp + bias;
686 if (!kstack_valid(tp, fp))
688 rw = (struct reg_window *) fp;
690 if (!in_sched_functions(pc)) {
694 fp = rw->ins[6] + bias;
695 } while (++count < 16);