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1/* linux/arch/sparc/kernel/process.c
2 *
3 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
5 */
6
7/*
8 * This file handles the architecture-dependent parts of process handling..
9 */
10
11#include <stdarg.h>
12
13#include <linux/errno.h>
14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
18#include <linux/stddef.h>
19#include <linux/ptrace.h>
20#include <linux/user.h>
21#include <linux/smp.h>
22#include <linux/reboot.h>
23#include <linux/delay.h>
24#include <linux/pm.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27
28#include <asm/auxio.h>
29#include <asm/oplib.h>
30#include <asm/uaccess.h>
31#include <asm/system.h>
32#include <asm/page.h>
33#include <asm/pgalloc.h>
34#include <asm/pgtable.h>
35#include <asm/delay.h>
36#include <asm/processor.h>
37#include <asm/psr.h>
38#include <asm/elf.h>
39#include <asm/prom.h>
40#include <asm/unistd.h>
41
42/*
43 * Power management idle function
44 * Set in pm platform drivers (apc.c and pmc.c)
45 */
46void (*pm_idle)(void);
47EXPORT_SYMBOL(pm_idle);
48
49/*
50 * Power-off handler instantiation for pm.h compliance
51 * This is done via auxio, but could be used as a fallback
52 * handler when auxio is not present-- unused for now...
53 */
54void (*pm_power_off)(void) = machine_power_off;
55EXPORT_SYMBOL(pm_power_off);
56
57/*
58 * sysctl - toggle power-off restriction for serial console
59 * systems in machine_power_off()
60 */
61int scons_pwroff = 1;
62
63extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
64
65struct task_struct *last_task_used_math = NULL;
66struct thread_info *current_set[NR_CPUS];
67
68#ifndef CONFIG_SMP
69
70#define SUN4C_FAULT_HIGH 100
71
72/*
73 * the idle loop on a Sparc... ;)
74 */
75void cpu_idle(void)
76{
77 /* endless idle loop with no priority at all */
78 for (;;) {
79 if (ARCH_SUN4C) {
80 static int count = HZ;
81 static unsigned long last_jiffies;
82 static unsigned long last_faults;
83 static unsigned long fps;
84 unsigned long now;
85 unsigned long faults;
86
87 extern unsigned long sun4c_kernel_faults;
88 extern void sun4c_grow_kernel_ring(void);
89
90 local_irq_disable();
91 now = jiffies;
92 count -= (now - last_jiffies);
93 last_jiffies = now;
94 if (count < 0) {
95 count += HZ;
96 faults = sun4c_kernel_faults;
97 fps = (fps + (faults - last_faults)) >> 1;
98 last_faults = faults;
99#if 0
100 printk("kernel faults / second = %ld\n", fps);
101#endif
102 if (fps >= SUN4C_FAULT_HIGH) {
103 sun4c_grow_kernel_ring();
104 }
105 }
106 local_irq_enable();
107 }
108
109 if (pm_idle) {
110 while (!need_resched())
111 (*pm_idle)();
112 } else {
113 while (!need_resched())
114 cpu_relax();
115 }
116 preempt_enable_no_resched();
117 schedule();
118 preempt_disable();
119 check_pgt_cache();
120 }
121}
122
123#else
124
125/* This is being executed in task 0 'user space'. */
126void cpu_idle(void)
127{
128 set_thread_flag(TIF_POLLING_NRFLAG);
129 /* endless idle loop with no priority at all */
130 while(1) {
131#ifdef CONFIG_SPARC_LEON
132 if (pm_idle) {
133 while (!need_resched())
134 (*pm_idle)();
135 } else
136#endif
137 {
138 while (!need_resched())
139 cpu_relax();
140 }
141 preempt_enable_no_resched();
142 schedule();
143 preempt_disable();
144 check_pgt_cache();
145 }
146}
147
148#endif
149
150/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
151void machine_halt(void)
152{
153 local_irq_enable();
154 mdelay(8);
155 local_irq_disable();
156 prom_halt();
157 panic("Halt failed!");
158}
159
160void machine_restart(char * cmd)
161{
162 char *p;
163
164 local_irq_enable();
165 mdelay(8);
166 local_irq_disable();
167
168 p = strchr (reboot_command, '\n');
169 if (p) *p = 0;
170 if (cmd)
171 prom_reboot(cmd);
172 if (*reboot_command)
173 prom_reboot(reboot_command);
174 prom_feval ("reset");
175 panic("Reboot failed!");
176}
177
178void machine_power_off(void)
179{
180 if (auxio_power_register &&
181 (strcmp(of_console_device->type, "serial") || scons_pwroff))
182 *auxio_power_register |= AUXIO_POWER_OFF;
183 machine_halt();
184}
185
186#if 0
187
188static DEFINE_SPINLOCK(sparc_backtrace_lock);
189
190void __show_backtrace(unsigned long fp)
191{
192 struct reg_window32 *rw;
193 unsigned long flags;
194 int cpu = smp_processor_id();
195
196 spin_lock_irqsave(&sparc_backtrace_lock, flags);
197
198 rw = (struct reg_window32 *)fp;
199 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
200 !(((unsigned long) rw) & 0x7)) {
201 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
202 "FP[%08lx] CALLER[%08lx]: ", cpu,
203 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
204 rw->ins[4], rw->ins[5],
205 rw->ins[6],
206 rw->ins[7]);
207 printk("%pS\n", (void *) rw->ins[7]);
208 rw = (struct reg_window32 *) rw->ins[6];
209 }
210 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
211}
212
213#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
214#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
215#define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
216
217void show_backtrace(void)
218{
219 unsigned long fp;
220
221 __SAVE; __SAVE; __SAVE; __SAVE;
222 __SAVE; __SAVE; __SAVE; __SAVE;
223 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
224 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
225
226 __GET_FP(fp);
227
228 __show_backtrace(fp);
229}
230
231#ifdef CONFIG_SMP
232void smp_show_backtrace_all_cpus(void)
233{
234 xc0((smpfunc_t) show_backtrace);
235 show_backtrace();
236}
237#endif
238
239void show_stackframe(struct sparc_stackf *sf)
240{
241 unsigned long size;
242 unsigned long *stk;
243 int i;
244
245 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
246 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
247 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
248 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
249 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
250 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
251 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
252 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
253 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
254 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
255 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
256 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
257 sf->xxargs[0]);
258 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
259 size -= STACKFRAME_SZ;
260 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
261 i = 0;
262 do {
263 printk("s%d: %08lx\n", i++, *stk++);
264 } while ((size -= sizeof(unsigned long)));
265}
266#endif
267
268void show_regs(struct pt_regs *r)
269{
270 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
271
272 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
273 r->psr, r->pc, r->npc, r->y, print_tainted());
274 printk("PC: <%pS>\n", (void *) r->pc);
275 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
276 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
277 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
278 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
279 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
280 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
281 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
282
283 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
284 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
285 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
286 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
287 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
288 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
289}
290
291/*
292 * The show_stack is an external API which we do not use ourselves.
293 * The oops is printed in die_if_kernel.
294 */
295void show_stack(struct task_struct *tsk, unsigned long *_ksp)
296{
297 unsigned long pc, fp;
298 unsigned long task_base;
299 struct reg_window32 *rw;
300 int count = 0;
301
302 if (tsk != NULL)
303 task_base = (unsigned long) task_stack_page(tsk);
304 else
305 task_base = (unsigned long) current_thread_info();
306
307 fp = (unsigned long) _ksp;
308 do {
309 /* Bogus frame pointer? */
310 if (fp < (task_base + sizeof(struct thread_info)) ||
311 fp >= (task_base + (PAGE_SIZE << 1)))
312 break;
313 rw = (struct reg_window32 *) fp;
314 pc = rw->ins[7];
315 printk("[%08lx : ", pc);
316 printk("%pS ] ", (void *) pc);
317 fp = rw->ins[6];
318 } while (++count < 16);
319 printk("\n");
320}
321
322void dump_stack(void)
323{
324 unsigned long *ksp;
325
326 __asm__ __volatile__("mov %%fp, %0"
327 : "=r" (ksp));
328 show_stack(current, ksp);
329}
330
331EXPORT_SYMBOL(dump_stack);
332
333/*
334 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
335 */
336unsigned long thread_saved_pc(struct task_struct *tsk)
337{
338 return task_thread_info(tsk)->kpc;
339}
340
341/*
342 * Free current thread data structures etc..
343 */
344void exit_thread(void)
345{
346#ifndef CONFIG_SMP
347 if(last_task_used_math == current) {
348#else
349 if (test_thread_flag(TIF_USEDFPU)) {
350#endif
351 /* Keep process from leaving FPU in a bogon state. */
352 put_psr(get_psr() | PSR_EF);
353 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
354 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
355#ifndef CONFIG_SMP
356 last_task_used_math = NULL;
357#else
358 clear_thread_flag(TIF_USEDFPU);
359#endif
360 }
361}
362
363void flush_thread(void)
364{
365 current_thread_info()->w_saved = 0;
366
367#ifndef CONFIG_SMP
368 if(last_task_used_math == current) {
369#else
370 if (test_thread_flag(TIF_USEDFPU)) {
371#endif
372 /* Clean the fpu. */
373 put_psr(get_psr() | PSR_EF);
374 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
375 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
376#ifndef CONFIG_SMP
377 last_task_used_math = NULL;
378#else
379 clear_thread_flag(TIF_USEDFPU);
380#endif
381 }
382
383 /* This task is no longer a kernel thread. */
384 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
385 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
386
387 /* We must fixup kregs as well. */
388 /* XXX This was not fixed for ti for a while, worked. Unused? */
389 current->thread.kregs = (struct pt_regs *)
390 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
391 }
392}
393
394static inline struct sparc_stackf __user *
395clone_stackframe(struct sparc_stackf __user *dst,
396 struct sparc_stackf __user *src)
397{
398 unsigned long size, fp;
399 struct sparc_stackf *tmp;
400 struct sparc_stackf __user *sp;
401
402 if (get_user(tmp, &src->fp))
403 return NULL;
404
405 fp = (unsigned long) tmp;
406 size = (fp - ((unsigned long) src));
407 fp = (unsigned long) dst;
408 sp = (struct sparc_stackf __user *)(fp - size);
409
410 /* do_fork() grabs the parent semaphore, we must release it
411 * temporarily so we can build the child clone stack frame
412 * without deadlocking.
413 */
414 if (__copy_user(sp, src, size))
415 sp = NULL;
416 else if (put_user(fp, &sp->fp))
417 sp = NULL;
418
419 return sp;
420}
421
422asmlinkage int sparc_do_fork(unsigned long clone_flags,
423 unsigned long stack_start,
424 struct pt_regs *regs,
425 unsigned long stack_size)
426{
427 unsigned long parent_tid_ptr, child_tid_ptr;
428 unsigned long orig_i1 = regs->u_regs[UREG_I1];
429 long ret;
430
431 parent_tid_ptr = regs->u_regs[UREG_I2];
432 child_tid_ptr = regs->u_regs[UREG_I4];
433
434 ret = do_fork(clone_flags, stack_start,
435 regs, stack_size,
436 (int __user *) parent_tid_ptr,
437 (int __user *) child_tid_ptr);
438
439 /* If we get an error and potentially restart the system
440 * call, we're screwed because copy_thread() clobbered
441 * the parent's %o1. So detect that case and restore it
442 * here.
443 */
444 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
445 regs->u_regs[UREG_I1] = orig_i1;
446
447 return ret;
448}
449
450/* Copy a Sparc thread. The fork() return value conventions
451 * under SunOS are nothing short of bletcherous:
452 * Parent --> %o0 == childs pid, %o1 == 0
453 * Child --> %o0 == parents pid, %o1 == 1
454 *
455 * NOTE: We have a separate fork kpsr/kwim because
456 * the parent could change these values between
457 * sys_fork invocation and when we reach here
458 * if the parent should sleep while trying to
459 * allocate the task_struct and kernel stack in
460 * do_fork().
461 * XXX See comment above sys_vfork in sparc64. todo.
462 */
463extern void ret_from_fork(void);
464
465int copy_thread(unsigned long clone_flags, unsigned long sp,
466 unsigned long unused,
467 struct task_struct *p, struct pt_regs *regs)
468{
469 struct thread_info *ti = task_thread_info(p);
470 struct pt_regs *childregs;
471 char *new_stack;
472
473#ifndef CONFIG_SMP
474 if(last_task_used_math == current) {
475#else
476 if (test_thread_flag(TIF_USEDFPU)) {
477#endif
478 put_psr(get_psr() | PSR_EF);
479 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
480 &p->thread.fpqueue[0], &p->thread.fpqdepth);
481#ifdef CONFIG_SMP
482 clear_thread_flag(TIF_USEDFPU);
483#endif
484 }
485
486 /*
487 * p->thread_info new_stack childregs
488 * ! ! ! {if(PSR_PS) }
489 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
490 * +----- - - - - - ------+===========+============={+==========}+
491 */
492 new_stack = task_stack_page(p) + THREAD_SIZE;
493 if (regs->psr & PSR_PS)
494 new_stack -= STACKFRAME_SZ;
495 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
496 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
497 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
498
499 /*
500 * A new process must start with interrupts closed in 2.5,
501 * because this is how Mingo's scheduler works (see schedule_tail
502 * and finish_arch_switch). If we do not do it, a timer interrupt hits
503 * before we unlock, attempts to re-take the rq->lock, and then we die.
504 * Thus, kpsr|=PSR_PIL.
505 */
506 ti->ksp = (unsigned long) new_stack;
507 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
508 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
509 ti->kwim = current->thread.fork_kwim;
510
511 if(regs->psr & PSR_PS) {
512 extern struct pt_regs fake_swapper_regs;
513
514 p->thread.kregs = &fake_swapper_regs;
515 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
516 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
517 p->thread.flags |= SPARC_FLAG_KTHREAD;
518 p->thread.current_ds = KERNEL_DS;
519 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
520 childregs->u_regs[UREG_G6] = (unsigned long) ti;
521 } else {
522 p->thread.kregs = childregs;
523 childregs->u_regs[UREG_FP] = sp;
524 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
525 p->thread.current_ds = USER_DS;
526
527 if (sp != regs->u_regs[UREG_FP]) {
528 struct sparc_stackf __user *childstack;
529 struct sparc_stackf __user *parentstack;
530
531 /*
532 * This is a clone() call with supplied user stack.
533 * Set some valid stack frames to give to the child.
534 */
535 childstack = (struct sparc_stackf __user *)
536 (sp & ~0xfUL);
537 parentstack = (struct sparc_stackf __user *)
538 regs->u_regs[UREG_FP];
539
540#if 0
541 printk("clone: parent stack:\n");
542 show_stackframe(parentstack);
543#endif
544
545 childstack = clone_stackframe(childstack, parentstack);
546 if (!childstack)
547 return -EFAULT;
548
549#if 0
550 printk("clone: child stack:\n");
551 show_stackframe(childstack);
552#endif
553
554 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
555 }
556 }
557
558#ifdef CONFIG_SMP
559 /* FPU must be disabled on SMP. */
560 childregs->psr &= ~PSR_EF;
561#endif
562
563 /* Set the return value for the child. */
564 childregs->u_regs[UREG_I0] = current->pid;
565 childregs->u_regs[UREG_I1] = 1;
566
567 /* Set the return value for the parent. */
568 regs->u_regs[UREG_I1] = 0;
569
570 if (clone_flags & CLONE_SETTLS)
571 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
572
573 return 0;
574}
575
576/*
577 * fill in the fpu structure for a core dump.
578 */
579int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
580{
581 if (used_math()) {
582 memset(fpregs, 0, sizeof(*fpregs));
583 fpregs->pr_q_entrysize = 8;
584 return 1;
585 }
586#ifdef CONFIG_SMP
587 if (test_thread_flag(TIF_USEDFPU)) {
588 put_psr(get_psr() | PSR_EF);
589 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
590 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
591 if (regs != NULL) {
592 regs->psr &= ~(PSR_EF);
593 clear_thread_flag(TIF_USEDFPU);
594 }
595 }
596#else
597 if (current == last_task_used_math) {
598 put_psr(get_psr() | PSR_EF);
599 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
600 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
601 if (regs != NULL) {
602 regs->psr &= ~(PSR_EF);
603 last_task_used_math = NULL;
604 }
605 }
606#endif
607 memcpy(&fpregs->pr_fr.pr_regs[0],
608 ¤t->thread.float_regs[0],
609 (sizeof(unsigned long) * 32));
610 fpregs->pr_fsr = current->thread.fsr;
611 fpregs->pr_qcnt = current->thread.fpqdepth;
612 fpregs->pr_q_entrysize = 8;
613 fpregs->pr_en = 1;
614 if(fpregs->pr_qcnt != 0) {
615 memcpy(&fpregs->pr_q[0],
616 ¤t->thread.fpqueue[0],
617 sizeof(struct fpq) * fpregs->pr_qcnt);
618 }
619 /* Zero out the rest. */
620 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
621 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
622 return 1;
623}
624
625/*
626 * sparc_execve() executes a new program after the asm stub has set
627 * things up for us. This should basically do what I want it to.
628 */
629asmlinkage int sparc_execve(struct pt_regs *regs)
630{
631 int error, base = 0;
632 char *filename;
633
634 /* Check for indirect call. */
635 if(regs->u_regs[UREG_G1] == 0)
636 base = 1;
637
638 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
639 error = PTR_ERR(filename);
640 if(IS_ERR(filename))
641 goto out;
642 error = do_execve(filename,
643 (const char __user *const __user *)
644 regs->u_regs[base + UREG_I1],
645 (const char __user *const __user *)
646 regs->u_regs[base + UREG_I2],
647 regs);
648 putname(filename);
649out:
650 return error;
651}
652
653/*
654 * This is the mechanism for creating a new kernel thread.
655 *
656 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
657 * who haven't done an "execve()") should use this: it will work within
658 * a system call from a "real" process, but the process memory space will
659 * not be freed until both the parent and the child have exited.
660 */
661pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
662{
663 long retval;
664
665 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
666 "mov %5, %%g3\n\t" /* and arg. */
667 "mov %1, %%g1\n\t"
668 "mov %2, %%o0\n\t" /* Clone flags. */
669 "mov 0, %%o1\n\t" /* usp arg == 0 */
670 "t 0x10\n\t" /* Linux/Sparc clone(). */
671 "cmp %%o1, 0\n\t"
672 "be 1f\n\t" /* The parent, just return. */
673 " nop\n\t" /* Delay slot. */
674 "jmpl %%g2, %%o7\n\t" /* Call the function. */
675 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
676 "mov %3, %%g1\n\t"
677 "t 0x10\n\t" /* Linux/Sparc exit(). */
678 /* Notreached by child. */
679 "1: mov %%o0, %0\n\t" :
680 "=r" (retval) :
681 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
682 "i" (__NR_exit), "r" (fn), "r" (arg) :
683 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
684 return retval;
685}
686EXPORT_SYMBOL(kernel_thread);
687
688unsigned long get_wchan(struct task_struct *task)
689{
690 unsigned long pc, fp, bias = 0;
691 unsigned long task_base = (unsigned long) task;
692 unsigned long ret = 0;
693 struct reg_window32 *rw;
694 int count = 0;
695
696 if (!task || task == current ||
697 task->state == TASK_RUNNING)
698 goto out;
699
700 fp = task_thread_info(task)->ksp + bias;
701 do {
702 /* Bogus frame pointer? */
703 if (fp < (task_base + sizeof(struct thread_info)) ||
704 fp >= (task_base + (2 * PAGE_SIZE)))
705 break;
706 rw = (struct reg_window32 *) fp;
707 pc = rw->ins[7];
708 if (!in_sched_functions(pc)) {
709 ret = pc;
710 goto out;
711 }
712 fp = rw->ins[6] + bias;
713 } while (++count < 16);
714
715out:
716 return ret;
717}
718
1/* linux/arch/sparc/kernel/process.c
2 *
3 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
5 */
6
7/*
8 * This file handles the architecture-dependent parts of process handling..
9 */
10
11#include <stdarg.h>
12
13#include <linux/elfcore.h>
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/stddef.h>
20#include <linux/ptrace.h>
21#include <linux/user.h>
22#include <linux/smp.h>
23#include <linux/reboot.h>
24#include <linux/delay.h>
25#include <linux/pm.h>
26#include <linux/slab.h>
27#include <linux/cpu.h>
28
29#include <asm/auxio.h>
30#include <asm/oplib.h>
31#include <asm/uaccess.h>
32#include <asm/page.h>
33#include <asm/pgalloc.h>
34#include <asm/pgtable.h>
35#include <asm/delay.h>
36#include <asm/processor.h>
37#include <asm/psr.h>
38#include <asm/elf.h>
39#include <asm/prom.h>
40#include <asm/unistd.h>
41#include <asm/setup.h>
42
43#include "kernel.h"
44
45/*
46 * Power management idle function
47 * Set in pm platform drivers (apc.c and pmc.c)
48 */
49void (*sparc_idle)(void);
50
51/*
52 * Power-off handler instantiation for pm.h compliance
53 * This is done via auxio, but could be used as a fallback
54 * handler when auxio is not present-- unused for now...
55 */
56void (*pm_power_off)(void) = machine_power_off;
57EXPORT_SYMBOL(pm_power_off);
58
59/*
60 * sysctl - toggle power-off restriction for serial console
61 * systems in machine_power_off()
62 */
63int scons_pwroff = 1;
64
65extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
66
67struct task_struct *last_task_used_math = NULL;
68struct thread_info *current_set[NR_CPUS];
69
70/* Idle loop support. */
71void arch_cpu_idle(void)
72{
73 if (sparc_idle)
74 (*sparc_idle)();
75 local_irq_enable();
76}
77
78/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
79void machine_halt(void)
80{
81 local_irq_enable();
82 mdelay(8);
83 local_irq_disable();
84 prom_halt();
85 panic("Halt failed!");
86}
87
88void machine_restart(char * cmd)
89{
90 char *p;
91
92 local_irq_enable();
93 mdelay(8);
94 local_irq_disable();
95
96 p = strchr (reboot_command, '\n');
97 if (p) *p = 0;
98 if (cmd)
99 prom_reboot(cmd);
100 if (*reboot_command)
101 prom_reboot(reboot_command);
102 prom_feval ("reset");
103 panic("Reboot failed!");
104}
105
106void machine_power_off(void)
107{
108 if (auxio_power_register &&
109 (strcmp(of_console_device->type, "serial") || scons_pwroff)) {
110 u8 power_register = sbus_readb(auxio_power_register);
111 power_register |= AUXIO_POWER_OFF;
112 sbus_writeb(power_register, auxio_power_register);
113 }
114
115 machine_halt();
116}
117
118void show_regs(struct pt_regs *r)
119{
120 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
121
122 show_regs_print_info(KERN_DEFAULT);
123
124 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
125 r->psr, r->pc, r->npc, r->y, print_tainted());
126 printk("PC: <%pS>\n", (void *) r->pc);
127 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
128 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
129 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
130 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
131 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
132 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
133 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
134
135 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
136 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
137 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
138 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
139 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
140 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
141}
142
143/*
144 * The show_stack is an external API which we do not use ourselves.
145 * The oops is printed in die_if_kernel.
146 */
147void show_stack(struct task_struct *tsk, unsigned long *_ksp)
148{
149 unsigned long pc, fp;
150 unsigned long task_base;
151 struct reg_window32 *rw;
152 int count = 0;
153
154 if (!tsk)
155 tsk = current;
156
157 if (tsk == current && !_ksp)
158 __asm__ __volatile__("mov %%fp, %0" : "=r" (_ksp));
159
160 task_base = (unsigned long) task_stack_page(tsk);
161 fp = (unsigned long) _ksp;
162 do {
163 /* Bogus frame pointer? */
164 if (fp < (task_base + sizeof(struct thread_info)) ||
165 fp >= (task_base + (PAGE_SIZE << 1)))
166 break;
167 rw = (struct reg_window32 *) fp;
168 pc = rw->ins[7];
169 printk("[%08lx : ", pc);
170 printk("%pS ] ", (void *) pc);
171 fp = rw->ins[6];
172 } while (++count < 16);
173 printk("\n");
174}
175
176/*
177 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
178 */
179unsigned long thread_saved_pc(struct task_struct *tsk)
180{
181 return task_thread_info(tsk)->kpc;
182}
183
184/*
185 * Free current thread data structures etc..
186 */
187void exit_thread(void)
188{
189#ifndef CONFIG_SMP
190 if(last_task_used_math == current) {
191#else
192 if (test_thread_flag(TIF_USEDFPU)) {
193#endif
194 /* Keep process from leaving FPU in a bogon state. */
195 put_psr(get_psr() | PSR_EF);
196 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
197 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
198#ifndef CONFIG_SMP
199 last_task_used_math = NULL;
200#else
201 clear_thread_flag(TIF_USEDFPU);
202#endif
203 }
204}
205
206void flush_thread(void)
207{
208 current_thread_info()->w_saved = 0;
209
210#ifndef CONFIG_SMP
211 if(last_task_used_math == current) {
212#else
213 if (test_thread_flag(TIF_USEDFPU)) {
214#endif
215 /* Clean the fpu. */
216 put_psr(get_psr() | PSR_EF);
217 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
218 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
219#ifndef CONFIG_SMP
220 last_task_used_math = NULL;
221#else
222 clear_thread_flag(TIF_USEDFPU);
223#endif
224 }
225
226 /* This task is no longer a kernel thread. */
227 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
228 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
229
230 /* We must fixup kregs as well. */
231 /* XXX This was not fixed for ti for a while, worked. Unused? */
232 current->thread.kregs = (struct pt_regs *)
233 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
234 }
235}
236
237static inline struct sparc_stackf __user *
238clone_stackframe(struct sparc_stackf __user *dst,
239 struct sparc_stackf __user *src)
240{
241 unsigned long size, fp;
242 struct sparc_stackf *tmp;
243 struct sparc_stackf __user *sp;
244
245 if (get_user(tmp, &src->fp))
246 return NULL;
247
248 fp = (unsigned long) tmp;
249 size = (fp - ((unsigned long) src));
250 fp = (unsigned long) dst;
251 sp = (struct sparc_stackf __user *)(fp - size);
252
253 /* do_fork() grabs the parent semaphore, we must release it
254 * temporarily so we can build the child clone stack frame
255 * without deadlocking.
256 */
257 if (__copy_user(sp, src, size))
258 sp = NULL;
259 else if (put_user(fp, &sp->fp))
260 sp = NULL;
261
262 return sp;
263}
264
265asmlinkage int sparc_do_fork(unsigned long clone_flags,
266 unsigned long stack_start,
267 struct pt_regs *regs,
268 unsigned long stack_size)
269{
270 unsigned long parent_tid_ptr, child_tid_ptr;
271 unsigned long orig_i1 = regs->u_regs[UREG_I1];
272 long ret;
273
274 parent_tid_ptr = regs->u_regs[UREG_I2];
275 child_tid_ptr = regs->u_regs[UREG_I4];
276
277 ret = do_fork(clone_flags, stack_start, stack_size,
278 (int __user *) parent_tid_ptr,
279 (int __user *) child_tid_ptr);
280
281 /* If we get an error and potentially restart the system
282 * call, we're screwed because copy_thread() clobbered
283 * the parent's %o1. So detect that case and restore it
284 * here.
285 */
286 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
287 regs->u_regs[UREG_I1] = orig_i1;
288
289 return ret;
290}
291
292/* Copy a Sparc thread. The fork() return value conventions
293 * under SunOS are nothing short of bletcherous:
294 * Parent --> %o0 == childs pid, %o1 == 0
295 * Child --> %o0 == parents pid, %o1 == 1
296 *
297 * NOTE: We have a separate fork kpsr/kwim because
298 * the parent could change these values between
299 * sys_fork invocation and when we reach here
300 * if the parent should sleep while trying to
301 * allocate the task_struct and kernel stack in
302 * do_fork().
303 * XXX See comment above sys_vfork in sparc64. todo.
304 */
305extern void ret_from_fork(void);
306extern void ret_from_kernel_thread(void);
307
308int copy_thread(unsigned long clone_flags, unsigned long sp,
309 unsigned long arg, struct task_struct *p)
310{
311 struct thread_info *ti = task_thread_info(p);
312 struct pt_regs *childregs, *regs = current_pt_regs();
313 char *new_stack;
314
315#ifndef CONFIG_SMP
316 if(last_task_used_math == current) {
317#else
318 if (test_thread_flag(TIF_USEDFPU)) {
319#endif
320 put_psr(get_psr() | PSR_EF);
321 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
322 &p->thread.fpqueue[0], &p->thread.fpqdepth);
323 }
324
325 /*
326 * p->thread_info new_stack childregs stack bottom
327 * ! ! ! !
328 * V V (stk.fr.) V (pt_regs) V
329 * +----- - - - - - ------+===========+=============+
330 */
331 new_stack = task_stack_page(p) + THREAD_SIZE;
332 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
333 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
334
335 /*
336 * A new process must start with interrupts disabled, see schedule_tail()
337 * and finish_task_switch(). (If we do not do it and if a timer interrupt
338 * hits before we unlock and attempts to take the rq->lock, we deadlock.)
339 *
340 * Thus, kpsr |= PSR_PIL.
341 */
342 ti->ksp = (unsigned long) new_stack;
343 p->thread.kregs = childregs;
344
345 if (unlikely(p->flags & PF_KTHREAD)) {
346 extern int nwindows;
347 unsigned long psr;
348 memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
349 p->thread.flags |= SPARC_FLAG_KTHREAD;
350 p->thread.current_ds = KERNEL_DS;
351 ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
352 childregs->u_regs[UREG_G1] = sp; /* function */
353 childregs->u_regs[UREG_G2] = arg;
354 psr = childregs->psr = get_psr();
355 ti->kpsr = psr | PSR_PIL;
356 ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
357 return 0;
358 }
359 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
360 childregs->u_regs[UREG_FP] = sp;
361 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
362 p->thread.current_ds = USER_DS;
363 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
364 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
365 ti->kwim = current->thread.fork_kwim;
366
367 if (sp != regs->u_regs[UREG_FP]) {
368 struct sparc_stackf __user *childstack;
369 struct sparc_stackf __user *parentstack;
370
371 /*
372 * This is a clone() call with supplied user stack.
373 * Set some valid stack frames to give to the child.
374 */
375 childstack = (struct sparc_stackf __user *)
376 (sp & ~0xfUL);
377 parentstack = (struct sparc_stackf __user *)
378 regs->u_regs[UREG_FP];
379
380#if 0
381 printk("clone: parent stack:\n");
382 show_stackframe(parentstack);
383#endif
384
385 childstack = clone_stackframe(childstack, parentstack);
386 if (!childstack)
387 return -EFAULT;
388
389#if 0
390 printk("clone: child stack:\n");
391 show_stackframe(childstack);
392#endif
393
394 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
395 }
396
397#ifdef CONFIG_SMP
398 /* FPU must be disabled on SMP. */
399 childregs->psr &= ~PSR_EF;
400 clear_tsk_thread_flag(p, TIF_USEDFPU);
401#endif
402
403 /* Set the return value for the child. */
404 childregs->u_regs[UREG_I0] = current->pid;
405 childregs->u_regs[UREG_I1] = 1;
406
407 /* Set the return value for the parent. */
408 regs->u_regs[UREG_I1] = 0;
409
410 if (clone_flags & CLONE_SETTLS)
411 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
412
413 return 0;
414}
415
416/*
417 * fill in the fpu structure for a core dump.
418 */
419int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
420{
421 if (used_math()) {
422 memset(fpregs, 0, sizeof(*fpregs));
423 fpregs->pr_q_entrysize = 8;
424 return 1;
425 }
426#ifdef CONFIG_SMP
427 if (test_thread_flag(TIF_USEDFPU)) {
428 put_psr(get_psr() | PSR_EF);
429 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
430 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
431 if (regs != NULL) {
432 regs->psr &= ~(PSR_EF);
433 clear_thread_flag(TIF_USEDFPU);
434 }
435 }
436#else
437 if (current == last_task_used_math) {
438 put_psr(get_psr() | PSR_EF);
439 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
440 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
441 if (regs != NULL) {
442 regs->psr &= ~(PSR_EF);
443 last_task_used_math = NULL;
444 }
445 }
446#endif
447 memcpy(&fpregs->pr_fr.pr_regs[0],
448 ¤t->thread.float_regs[0],
449 (sizeof(unsigned long) * 32));
450 fpregs->pr_fsr = current->thread.fsr;
451 fpregs->pr_qcnt = current->thread.fpqdepth;
452 fpregs->pr_q_entrysize = 8;
453 fpregs->pr_en = 1;
454 if(fpregs->pr_qcnt != 0) {
455 memcpy(&fpregs->pr_q[0],
456 ¤t->thread.fpqueue[0],
457 sizeof(struct fpq) * fpregs->pr_qcnt);
458 }
459 /* Zero out the rest. */
460 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
461 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
462 return 1;
463}
464
465unsigned long get_wchan(struct task_struct *task)
466{
467 unsigned long pc, fp, bias = 0;
468 unsigned long task_base = (unsigned long) task;
469 unsigned long ret = 0;
470 struct reg_window32 *rw;
471 int count = 0;
472
473 if (!task || task == current ||
474 task->state == TASK_RUNNING)
475 goto out;
476
477 fp = task_thread_info(task)->ksp + bias;
478 do {
479 /* Bogus frame pointer? */
480 if (fp < (task_base + sizeof(struct thread_info)) ||
481 fp >= (task_base + (2 * PAGE_SIZE)))
482 break;
483 rw = (struct reg_window32 *) fp;
484 pc = rw->ins[7];
485 if (!in_sched_functions(pc)) {
486 ret = pc;
487 goto out;
488 }
489 fp = rw->ins[6] + bias;
490 } while (++count < 16);
491
492out:
493 return ret;
494}
495