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];
69 * the idle loop on a Sparc... ;)
73 set_thread_flag(TIF_POLLING_NRFLAG);
75 /* endless idle loop with no priority at all */
77 while (!need_resched()) {
83 schedule_preempt_disabled();
87 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
88 void machine_halt(void)
94 panic("Halt failed!");
97 void machine_restart(char * cmd)
105 p = strchr (reboot_command, '\n');
110 prom_reboot(reboot_command);
111 prom_feval ("reset");
112 panic("Reboot failed!");
115 void machine_power_off(void)
117 if (auxio_power_register &&
118 (strcmp(of_console_device->type, "serial") || scons_pwroff))
119 *auxio_power_register |= AUXIO_POWER_OFF;
123 void show_regs(struct pt_regs *r)
125 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14];
127 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
128 r->psr, r->pc, r->npc, r->y, print_tainted());
129 printk("PC: <%pS>\n", (void *) r->pc);
130 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
131 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
132 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
133 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
134 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
135 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
136 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
138 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
139 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
140 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
141 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
142 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
143 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
147 * The show_stack is an external API which we do not use ourselves.
148 * The oops is printed in die_if_kernel.
150 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
152 unsigned long pc, fp;
153 unsigned long task_base;
154 struct reg_window32 *rw;
158 task_base = (unsigned long) task_stack_page(tsk);
160 task_base = (unsigned long) current_thread_info();
162 fp = (unsigned long) _ksp;
164 /* Bogus frame pointer? */
165 if (fp < (task_base + sizeof(struct thread_info)) ||
166 fp >= (task_base + (PAGE_SIZE << 1)))
168 rw = (struct reg_window32 *) fp;
170 printk("[%08lx : ", pc);
171 printk("%pS ] ", (void *) pc);
173 } while (++count < 16);
177 void dump_stack(void)
181 __asm__ __volatile__("mov %%fp, %0"
183 show_stack(current, ksp);
186 EXPORT_SYMBOL(dump_stack);
189 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
191 unsigned long thread_saved_pc(struct task_struct *tsk)
193 return task_thread_info(tsk)->kpc;
197 * Free current thread data structures etc..
199 void exit_thread(void)
202 if(last_task_used_math == current) {
204 if (test_thread_flag(TIF_USEDFPU)) {
206 /* Keep process from leaving FPU in a bogon state. */
207 put_psr(get_psr() | PSR_EF);
208 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
209 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
211 last_task_used_math = NULL;
213 clear_thread_flag(TIF_USEDFPU);
218 void flush_thread(void)
220 current_thread_info()->w_saved = 0;
223 if(last_task_used_math == current) {
225 if (test_thread_flag(TIF_USEDFPU)) {
228 put_psr(get_psr() | PSR_EF);
229 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
230 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
232 last_task_used_math = NULL;
234 clear_thread_flag(TIF_USEDFPU);
238 /* This task is no longer a kernel thread. */
239 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
240 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
242 /* We must fixup kregs as well. */
243 /* XXX This was not fixed for ti for a while, worked. Unused? */
244 current->thread.kregs = (struct pt_regs *)
245 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
249 static inline struct sparc_stackf __user *
250 clone_stackframe(struct sparc_stackf __user *dst,
251 struct sparc_stackf __user *src)
253 unsigned long size, fp;
254 struct sparc_stackf *tmp;
255 struct sparc_stackf __user *sp;
257 if (get_user(tmp, &src->fp))
260 fp = (unsigned long) tmp;
261 size = (fp - ((unsigned long) src));
262 fp = (unsigned long) dst;
263 sp = (struct sparc_stackf __user *)(fp - size);
265 /* do_fork() grabs the parent semaphore, we must release it
266 * temporarily so we can build the child clone stack frame
267 * without deadlocking.
269 if (__copy_user(sp, src, size))
271 else if (put_user(fp, &sp->fp))
277 asmlinkage int sparc_do_fork(unsigned long clone_flags,
278 unsigned long stack_start,
279 struct pt_regs *regs,
280 unsigned long stack_size)
282 unsigned long parent_tid_ptr, child_tid_ptr;
283 unsigned long orig_i1 = regs->u_regs[UREG_I1];
286 parent_tid_ptr = regs->u_regs[UREG_I2];
287 child_tid_ptr = regs->u_regs[UREG_I4];
289 ret = do_fork(clone_flags, stack_start,
291 (int __user *) parent_tid_ptr,
292 (int __user *) child_tid_ptr);
294 /* If we get an error and potentially restart the system
295 * call, we're screwed because copy_thread() clobbered
296 * the parent's %o1. So detect that case and restore it
299 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
300 regs->u_regs[UREG_I1] = orig_i1;
305 /* Copy a Sparc thread. The fork() return value conventions
306 * under SunOS are nothing short of bletcherous:
307 * Parent --> %o0 == childs pid, %o1 == 0
308 * Child --> %o0 == parents pid, %o1 == 1
310 * NOTE: We have a separate fork kpsr/kwim because
311 * the parent could change these values between
312 * sys_fork invocation and when we reach here
313 * if the parent should sleep while trying to
314 * allocate the task_struct and kernel stack in
316 * XXX See comment above sys_vfork in sparc64. todo.
318 extern void ret_from_fork(void);
320 int copy_thread(unsigned long clone_flags, unsigned long sp,
321 unsigned long unused,
322 struct task_struct *p, struct pt_regs *regs)
324 struct thread_info *ti = task_thread_info(p);
325 struct pt_regs *childregs;
329 if(last_task_used_math == current) {
331 if (test_thread_flag(TIF_USEDFPU)) {
333 put_psr(get_psr() | PSR_EF);
334 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
335 &p->thread.fpqueue[0], &p->thread.fpqdepth);
337 clear_thread_flag(TIF_USEDFPU);
342 * p->thread_info new_stack childregs
343 * ! ! ! {if(PSR_PS) }
344 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
345 * +----- - - - - - ------+===========+============={+==========}+
347 new_stack = task_stack_page(p) + THREAD_SIZE;
348 if (regs->psr & PSR_PS)
349 new_stack -= STACKFRAME_SZ;
350 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
351 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
352 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
355 * A new process must start with interrupts closed in 2.5,
356 * because this is how Mingo's scheduler works (see schedule_tail
357 * and finish_arch_switch). If we do not do it, a timer interrupt hits
358 * before we unlock, attempts to re-take the rq->lock, and then we die.
359 * Thus, kpsr|=PSR_PIL.
361 ti->ksp = (unsigned long) new_stack;
362 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
363 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
364 ti->kwim = current->thread.fork_kwim;
366 if(regs->psr & PSR_PS) {
367 extern struct pt_regs fake_swapper_regs;
369 p->thread.kregs = &fake_swapper_regs;
370 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
371 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
372 p->thread.flags |= SPARC_FLAG_KTHREAD;
373 p->thread.current_ds = KERNEL_DS;
374 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
375 childregs->u_regs[UREG_G6] = (unsigned long) ti;
377 p->thread.kregs = childregs;
378 childregs->u_regs[UREG_FP] = sp;
379 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
380 p->thread.current_ds = USER_DS;
382 if (sp != regs->u_regs[UREG_FP]) {
383 struct sparc_stackf __user *childstack;
384 struct sparc_stackf __user *parentstack;
387 * This is a clone() call with supplied user stack.
388 * Set some valid stack frames to give to the child.
390 childstack = (struct sparc_stackf __user *)
392 parentstack = (struct sparc_stackf __user *)
393 regs->u_regs[UREG_FP];
396 printk("clone: parent stack:\n");
397 show_stackframe(parentstack);
400 childstack = clone_stackframe(childstack, parentstack);
405 printk("clone: child stack:\n");
406 show_stackframe(childstack);
409 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
414 /* FPU must be disabled on SMP. */
415 childregs->psr &= ~PSR_EF;
418 /* Set the return value for the child. */
419 childregs->u_regs[UREG_I0] = current->pid;
420 childregs->u_regs[UREG_I1] = 1;
422 /* Set the return value for the parent. */
423 regs->u_regs[UREG_I1] = 0;
425 if (clone_flags & CLONE_SETTLS)
426 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
432 * fill in the fpu structure for a core dump.
434 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
437 memset(fpregs, 0, sizeof(*fpregs));
438 fpregs->pr_q_entrysize = 8;
442 if (test_thread_flag(TIF_USEDFPU)) {
443 put_psr(get_psr() | PSR_EF);
444 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
445 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
447 regs->psr &= ~(PSR_EF);
448 clear_thread_flag(TIF_USEDFPU);
452 if (current == last_task_used_math) {
453 put_psr(get_psr() | PSR_EF);
454 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr,
455 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth);
457 regs->psr &= ~(PSR_EF);
458 last_task_used_math = NULL;
462 memcpy(&fpregs->pr_fr.pr_regs[0],
463 ¤t->thread.float_regs[0],
464 (sizeof(unsigned long) * 32));
465 fpregs->pr_fsr = current->thread.fsr;
466 fpregs->pr_qcnt = current->thread.fpqdepth;
467 fpregs->pr_q_entrysize = 8;
469 if(fpregs->pr_qcnt != 0) {
470 memcpy(&fpregs->pr_q[0],
471 ¤t->thread.fpqueue[0],
472 sizeof(struct fpq) * fpregs->pr_qcnt);
474 /* Zero out the rest. */
475 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
476 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
481 * sparc_execve() executes a new program after the asm stub has set
482 * things up for us. This should basically do what I want it to.
484 asmlinkage int sparc_execve(struct pt_regs *regs)
489 /* Check for indirect call. */
490 if(regs->u_regs[UREG_G1] == 0)
493 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
494 error = PTR_ERR(filename);
497 error = do_execve(filename,
498 (const char __user *const __user *)
499 regs->u_regs[base + UREG_I1],
500 (const char __user *const __user *)
501 regs->u_regs[base + UREG_I2],
509 * This is the mechanism for creating a new kernel thread.
511 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
512 * who haven't done an "execve()") should use this: it will work within
513 * a system call from a "real" process, but the process memory space will
514 * not be freed until both the parent and the child have exited.
516 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
520 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
521 "mov %5, %%g3\n\t" /* and arg. */
523 "mov %2, %%o0\n\t" /* Clone flags. */
524 "mov 0, %%o1\n\t" /* usp arg == 0 */
525 "t 0x10\n\t" /* Linux/Sparc clone(). */
527 "be 1f\n\t" /* The parent, just return. */
528 " nop\n\t" /* Delay slot. */
529 "jmpl %%g2, %%o7\n\t" /* Call the function. */
530 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
532 "t 0x10\n\t" /* Linux/Sparc exit(). */
533 /* Notreached by child. */
534 "1: mov %%o0, %0\n\t" :
536 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
537 "i" (__NR_exit), "r" (fn), "r" (arg) :
538 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
541 EXPORT_SYMBOL(kernel_thread);
543 unsigned long get_wchan(struct task_struct *task)
545 unsigned long pc, fp, bias = 0;
546 unsigned long task_base = (unsigned long) task;
547 unsigned long ret = 0;
548 struct reg_window32 *rw;
551 if (!task || task == current ||
552 task->state == TASK_RUNNING)
555 fp = task_thread_info(task)->ksp + bias;
557 /* Bogus frame pointer? */
558 if (fp < (task_base + sizeof(struct thread_info)) ||
559 fp >= (task_base + (2 * PAGE_SIZE)))
561 rw = (struct reg_window32 *) fp;
563 if (!in_sched_functions(pc)) {
567 fp = rw->ins[6] + bias;
568 } while (++count < 16);