1 /* linux/arch/sparc/kernel/process.c
3 * Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
8 * This file handles the architecture-dependent parts of process handling..
13 #include <linux/errno.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.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>
25 #include <linux/init.h>
26 #include <linux/slab.h>
28 #include <asm/auxio.h>
29 #include <asm/oplib.h>
30 #include <asm/uaccess.h>
32 #include <asm/pgalloc.h>
33 #include <asm/pgtable.h>
34 #include <asm/delay.h>
35 #include <asm/processor.h>
39 #include <asm/unistd.h>
40 #include <asm/setup.h>
43 * Power management idle function
44 * Set in pm platform drivers (apc.c and pmc.c)
46 void (*pm_idle)(void);
47 EXPORT_SYMBOL(pm_idle);
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...
54 void (*pm_power_off)(void) = machine_power_off;
55 EXPORT_SYMBOL(pm_power_off);
58 * sysctl - toggle power-off restriction for serial console
59 * systems in machine_power_off()
63 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
65 struct task_struct *last_task_used_math = NULL;
66 struct thread_info *current_set[NR_CPUS];
71 * the idle loop on a Sparc... ;)
75 /* endless idle loop with no priority at all */
78 while (!need_resched())
81 while (!need_resched())
84 schedule_preempt_disabled();
90 /* This is being executed in task 0 'user space'. */
93 set_thread_flag(TIF_POLLING_NRFLAG);
94 /* endless idle loop with no priority at all */
96 #ifdef CONFIG_SPARC_LEON
98 while (!need_resched())
103 while (!need_resched())
106 schedule_preempt_disabled();
112 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
113 void machine_halt(void)
119 panic("Halt failed!");
122 void machine_restart(char * cmd)
130 p = strchr (reboot_command, '\n');
135 prom_reboot(reboot_command);
136 prom_feval ("reset");
137 panic("Reboot failed!");
140 void machine_power_off(void)
142 if (auxio_power_register &&
143 (strcmp(of_console_device->type, "serial") || scons_pwroff))
144 *auxio_power_register |= AUXIO_POWER_OFF;
148 void show_regs(struct pt_regs *r)
150 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
152 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
153 r->psr, r->pc, r->npc, r->y, print_tainted());
154 printk("PC: <%pS>\n", (void *) r->pc);
155 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
156 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
157 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
158 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
159 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
160 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
161 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
163 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
164 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
165 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
166 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
167 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
168 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
172 * The show_stack is an external API which we do not use ourselves.
173 * The oops is printed in die_if_kernel.
175 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
177 unsigned long pc, fp;
178 unsigned long task_base;
179 struct reg_window32 *rw;
183 task_base = (unsigned long) task_stack_page(tsk);
185 task_base = (unsigned long) current_thread_info();
187 fp = (unsigned long) _ksp;
189 /* Bogus frame pointer? */
190 if (fp < (task_base + sizeof(struct thread_info)) ||
191 fp >= (task_base + (PAGE_SIZE << 1)))
193 rw = (struct reg_window32 *) fp;
195 printk("[%08lx : ", pc);
196 printk("%pS ] ", (void *) pc);
198 } while (++count < 16);
202 void dump_stack(void)
206 __asm__ __volatile__("mov %%fp, %0"
208 show_stack(current, ksp);
211 EXPORT_SYMBOL(dump_stack);
214 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
216 unsigned long thread_saved_pc(struct task_struct *tsk)
218 return task_thread_info(tsk)->kpc;
222 * Free current thread data structures etc..
224 void exit_thread(void)
227 if(last_task_used_math == current) {
229 if (test_thread_flag(TIF_USEDFPU)) {
231 /* Keep process from leaving FPU in a bogon state. */
232 put_psr(get_psr() | PSR_EF);
233 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
234 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
236 last_task_used_math = NULL;
238 clear_thread_flag(TIF_USEDFPU);
243 void flush_thread(void)
245 current_thread_info()->w_saved = 0;
248 if(last_task_used_math == current) {
250 if (test_thread_flag(TIF_USEDFPU)) {
253 put_psr(get_psr() | PSR_EF);
254 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
255 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
257 last_task_used_math = NULL;
259 clear_thread_flag(TIF_USEDFPU);
263 /* This task is no longer a kernel thread. */
264 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
265 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
267 /* We must fixup kregs as well. */
268 /* XXX This was not fixed for ti for a while, worked. Unused? */
269 current->thread.kregs = (struct pt_regs *)
270 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
274 static inline struct sparc_stackf __user *
275 clone_stackframe(struct sparc_stackf __user *dst,
276 struct sparc_stackf __user *src)
278 unsigned long size, fp;
279 struct sparc_stackf *tmp;
280 struct sparc_stackf __user *sp;
282 if (get_user(tmp, &src->fp))
285 fp = (unsigned long) tmp;
286 size = (fp - ((unsigned long) src));
287 fp = (unsigned long) dst;
288 sp = (struct sparc_stackf __user *)(fp - size);
290 /* do_fork() grabs the parent semaphore, we must release it
291 * temporarily so we can build the child clone stack frame
292 * without deadlocking.
294 if (__copy_user(sp, src, size))
296 else if (put_user(fp, &sp->fp))
302 asmlinkage int sparc_do_fork(unsigned long clone_flags,
303 unsigned long stack_start,
304 struct pt_regs *regs,
305 unsigned long stack_size)
307 unsigned long parent_tid_ptr, child_tid_ptr;
308 unsigned long orig_i1 = regs->u_regs[UREG_I1];
311 parent_tid_ptr = regs->u_regs[UREG_I2];
312 child_tid_ptr = regs->u_regs[UREG_I4];
314 ret = do_fork(clone_flags, stack_start,
316 (int __user *) parent_tid_ptr,
317 (int __user *) child_tid_ptr);
319 /* If we get an error and potentially restart the system
320 * call, we're screwed because copy_thread() clobbered
321 * the parent's %o1. So detect that case and restore it
324 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
325 regs->u_regs[UREG_I1] = orig_i1;
330 /* Copy a Sparc thread. The fork() return value conventions
331 * under SunOS are nothing short of bletcherous:
332 * Parent --> %o0 == childs pid, %o1 == 0
333 * Child --> %o0 == parents pid, %o1 == 1
335 * NOTE: We have a separate fork kpsr/kwim because
336 * the parent could change these values between
337 * sys_fork invocation and when we reach here
338 * if the parent should sleep while trying to
339 * allocate the task_struct and kernel stack in
341 * XXX See comment above sys_vfork in sparc64. todo.
343 extern void ret_from_fork(void);
345 int copy_thread(unsigned long clone_flags, unsigned long sp,
346 unsigned long unused,
347 struct task_struct *p, struct pt_regs *regs)
349 struct thread_info *ti = task_thread_info(p);
350 struct pt_regs *childregs;
354 if(last_task_used_math == current) {
356 if (test_thread_flag(TIF_USEDFPU)) {
358 put_psr(get_psr() | PSR_EF);
359 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
360 &p->thread.fpqueue[0], &p->thread.fpqdepth);
362 clear_thread_flag(TIF_USEDFPU);
367 * p->thread_info new_stack childregs
368 * ! ! ! {if(PSR_PS) }
369 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
370 * +----- - - - - - ------+===========+============={+==========}+
372 new_stack = task_stack_page(p) + THREAD_SIZE;
373 if (regs->psr & PSR_PS)
374 new_stack -= STACKFRAME_SZ;
375 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
376 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
377 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
380 * A new process must start with interrupts closed in 2.5,
381 * because this is how Mingo's scheduler works (see schedule_tail
382 * and finish_arch_switch). If we do not do it, a timer interrupt hits
383 * before we unlock, attempts to re-take the rq->lock, and then we die.
384 * Thus, kpsr|=PSR_PIL.
386 ti->ksp = (unsigned long) new_stack;
387 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
388 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
389 ti->kwim = current->thread.fork_kwim;
391 if(regs->psr & PSR_PS) {
392 extern struct pt_regs fake_swapper_regs;
394 p->thread.kregs = &fake_swapper_regs;
395 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
396 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
397 p->thread.flags |= SPARC_FLAG_KTHREAD;
398 p->thread.current_ds = KERNEL_DS;
399 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
400 childregs->u_regs[UREG_G6] = (unsigned long) ti;
402 p->thread.kregs = childregs;
403 childregs->u_regs[UREG_FP] = sp;
404 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
405 p->thread.current_ds = USER_DS;
407 if (sp != regs->u_regs[UREG_FP]) {
408 struct sparc_stackf __user *childstack;
409 struct sparc_stackf __user *parentstack;
412 * This is a clone() call with supplied user stack.
413 * Set some valid stack frames to give to the child.
415 childstack = (struct sparc_stackf __user *)
417 parentstack = (struct sparc_stackf __user *)
418 regs->u_regs[UREG_FP];
421 printk("clone: parent stack:\n");
422 show_stackframe(parentstack);
425 childstack = clone_stackframe(childstack, parentstack);
430 printk("clone: child stack:\n");
431 show_stackframe(childstack);
434 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
439 /* FPU must be disabled on SMP. */
440 childregs->psr &= ~PSR_EF;
443 /* Set the return value for the child. */
444 childregs->u_regs[UREG_I0] = current->pid;
445 childregs->u_regs[UREG_I1] = 1;
447 /* Set the return value for the parent. */
448 regs->u_regs[UREG_I1] = 0;
450 if (clone_flags & CLONE_SETTLS)
451 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
457 * fill in the fpu structure for a core dump.
459 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
462 memset(fpregs, 0, sizeof(*fpregs));
463 fpregs->pr_q_entrysize = 8;
467 if (test_thread_flag(TIF_USEDFPU)) {
468 put_psr(get_psr() | PSR_EF);
469 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
470 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
472 regs->psr &= ~(PSR_EF);
473 clear_thread_flag(TIF_USEDFPU);
477 if (current == last_task_used_math) {
478 put_psr(get_psr() | PSR_EF);
479 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
480 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
482 regs->psr &= ~(PSR_EF);
483 last_task_used_math = NULL;
487 memcpy(&fpregs->pr_fr.pr_regs[0],
488 ¤t->thread.float_regs[0],
489 (sizeof(unsigned long) * 32));
490 fpregs->pr_fsr = current->thread.fsr;
491 fpregs->pr_qcnt = current->thread.fpqdepth;
492 fpregs->pr_q_entrysize = 8;
494 if(fpregs->pr_qcnt != 0) {
495 memcpy(&fpregs->pr_q[0],
496 ¤t->thread.fpqueue[0],
497 sizeof(struct fpq) * fpregs->pr_qcnt);
499 /* Zero out the rest. */
500 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
501 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
506 * sparc_execve() executes a new program after the asm stub has set
507 * things up for us. This should basically do what I want it to.
509 asmlinkage int sparc_execve(struct pt_regs *regs)
514 /* Check for indirect call. */
515 if(regs->u_regs[UREG_G1] == 0)
518 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
519 error = PTR_ERR(filename);
522 error = do_execve(filename,
523 (const char __user *const __user *)
524 regs->u_regs[base + UREG_I1],
525 (const char __user *const __user *)
526 regs->u_regs[base + UREG_I2],
534 * This is the mechanism for creating a new kernel thread.
536 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
537 * who haven't done an "execve()") should use this: it will work within
538 * a system call from a "real" process, but the process memory space will
539 * not be freed until both the parent and the child have exited.
541 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
545 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
546 "mov %5, %%g3\n\t" /* and arg. */
548 "mov %2, %%o0\n\t" /* Clone flags. */
549 "mov 0, %%o1\n\t" /* usp arg == 0 */
550 "t 0x10\n\t" /* Linux/Sparc clone(). */
552 "be 1f\n\t" /* The parent, just return. */
553 " nop\n\t" /* Delay slot. */
554 "jmpl %%g2, %%o7\n\t" /* Call the function. */
555 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
557 "t 0x10\n\t" /* Linux/Sparc exit(). */
558 /* Notreached by child. */
559 "1: mov %%o0, %0\n\t" :
561 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
562 "i" (__NR_exit), "r" (fn), "r" (arg) :
563 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
566 EXPORT_SYMBOL(kernel_thread);
568 unsigned long get_wchan(struct task_struct *task)
570 unsigned long pc, fp, bias = 0;
571 unsigned long task_base = (unsigned long) task;
572 unsigned long ret = 0;
573 struct reg_window32 *rw;
576 if (!task || task == current ||
577 task->state == TASK_RUNNING)
580 fp = task_thread_info(task)->ksp + bias;
582 /* Bogus frame pointer? */
583 if (fp < (task_base + sizeof(struct thread_info)) ||
584 fp >= (task_base + (2 * PAGE_SIZE)))
586 rw = (struct reg_window32 *) fp;
588 if (!in_sched_functions(pc)) {
592 fp = rw->ins[6] + bias;
593 } while (++count < 16);