blob: c151863906932239309079c0719d8d13b148b2b1 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/alpha/kernel/process.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
7/*
8 * This file handles the architecture-dependent parts of process handling.
9 */
10
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/errno.h>
12#include <linux/module.h>
13#include <linux/sched.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/smp.h>
17#include <linux/smp_lock.h>
18#include <linux/stddef.h>
19#include <linux/unistd.h>
20#include <linux/ptrace.h>
21#include <linux/slab.h>
22#include <linux/user.h>
23#include <linux/a.out.h>
24#include <linux/utsname.h>
25#include <linux/time.h>
26#include <linux/major.h>
27#include <linux/stat.h>
Jon Smirla8f340e2006-07-10 04:44:12 -070028#include <linux/vt.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/mman.h>
30#include <linux/elfcore.h>
31#include <linux/reboot.h>
32#include <linux/tty.h>
33#include <linux/console.h>
34
35#include <asm/reg.h>
36#include <asm/uaccess.h>
37#include <asm/system.h>
38#include <asm/io.h>
39#include <asm/pgtable.h>
40#include <asm/hwrpb.h>
41#include <asm/fpu.h>
42
43#include "proto.h"
44#include "pci_impl.h"
45
Eric W. Biederman5e382912006-01-08 01:03:46 -080046/*
47 * Power off function, if any
48 */
49void (*pm_power_off)(void) = machine_power_off;
Al Viro89eb1692007-01-30 13:23:25 +000050EXPORT_SYMBOL(pm_power_off);
Eric W. Biederman5e382912006-01-08 01:03:46 -080051
Linus Torvalds1da177e2005-04-16 15:20:36 -070052void
53cpu_idle(void)
54{
Nick Piggin64c7c8f2005-11-08 21:39:04 -080055 set_thread_flag(TIF_POLLING_NRFLAG);
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 /* FIXME -- EV6 and LCA45 know how to power down
59 the CPU. */
60
61 while (!need_resched())
Nick Piggin64c7c8f2005-11-08 21:39:04 -080062 cpu_relax();
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 schedule();
64 }
65}
66
67
68struct halt_info {
69 int mode;
70 char *restart_cmd;
71};
72
73static void
74common_shutdown_1(void *generic_ptr)
75{
76 struct halt_info *how = (struct halt_info *)generic_ptr;
77 struct percpu_struct *cpup;
78 unsigned long *pflags, flags;
79 int cpuid = smp_processor_id();
80
81 /* No point in taking interrupts anymore. */
82 local_irq_disable();
83
84 cpup = (struct percpu_struct *)
85 ((unsigned long)hwrpb + hwrpb->processor_offset
86 + hwrpb->processor_size * cpuid);
87 pflags = &cpup->flags;
88 flags = *pflags;
89
90 /* Clear reason to "default"; clear "bootstrap in progress". */
91 flags &= ~0x00ff0001UL;
92
93#ifdef CONFIG_SMP
94 /* Secondaries halt here. */
95 if (cpuid != boot_cpuid) {
96 flags |= 0x00040000UL; /* "remain halted" */
97 *pflags = flags;
Ivan Kokshayskyc7d2d282006-06-04 02:51:34 -070098 cpu_clear(cpuid, cpu_present_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 halt();
100 }
101#endif
102
103 if (how->mode == LINUX_REBOOT_CMD_RESTART) {
104 if (!how->restart_cmd) {
105 flags |= 0x00020000UL; /* "cold bootstrap" */
106 } else {
107 /* For SRM, we could probably set environment
108 variables to get this to work. We'd have to
109 delay this until after srm_paging_stop unless
110 we ever got srm_fixup working.
111
112 At the moment, SRM will use the last boot device,
113 but the file and flags will be the defaults, when
114 doing a "warm" bootstrap. */
115 flags |= 0x00030000UL; /* "warm bootstrap" */
116 }
117 } else {
118 flags |= 0x00040000UL; /* "remain halted" */
119 }
120 *pflags = flags;
121
122#ifdef CONFIG_SMP
123 /* Wait for the secondaries to halt. */
Ivan Kokshayskyc7d2d282006-06-04 02:51:34 -0700124 cpu_clear(boot_cpuid, cpu_present_map);
125 while (cpus_weight(cpu_present_map))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 barrier();
127#endif
128
129 /* If booted from SRM, reset some of the original environment. */
130 if (alpha_using_srm) {
131#ifdef CONFIG_DUMMY_CONSOLE
Ivan Kokshaysky4b3c86a2005-09-22 21:43:57 -0700132 /* If we've gotten here after SysRq-b, leave interrupt
133 context before taking over the console. */
134 if (in_interrupt())
135 irq_exit();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 /* This has the effect of resetting the VGA video origin. */
137 take_over_console(&dummy_con, 0, MAX_NR_CONSOLES-1, 1);
138#endif
139 pci_restore_srm_config();
140 set_hae(srm_hae);
141 }
142
143 if (alpha_mv.kill_arch)
144 alpha_mv.kill_arch(how->mode);
145
146 if (! alpha_using_srm && how->mode != LINUX_REBOOT_CMD_RESTART) {
147 /* Unfortunately, since MILO doesn't currently understand
148 the hwrpb bits above, we can't reliably halt the
149 processor and keep it halted. So just loop. */
150 return;
151 }
152
153 if (alpha_using_srm)
154 srm_paging_stop();
155
156 halt();
157}
158
159static void
160common_shutdown(int mode, char *restart_cmd)
161{
162 struct halt_info args;
163 args.mode = mode;
164 args.restart_cmd = restart_cmd;
165 on_each_cpu(common_shutdown_1, &args, 1, 0);
166}
167
168void
169machine_restart(char *restart_cmd)
170{
171 common_shutdown(LINUX_REBOOT_CMD_RESTART, restart_cmd);
172}
173
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
175void
176machine_halt(void)
177{
178 common_shutdown(LINUX_REBOOT_CMD_HALT, NULL);
179}
180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182void
183machine_power_off(void)
184{
185 common_shutdown(LINUX_REBOOT_CMD_POWER_OFF, NULL);
186}
187
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189/* Used by sysrq-p, among others. I don't believe r9-r15 are ever
190 saved in the context it's used. */
191
192void
193show_regs(struct pt_regs *regs)
194{
195 dik_show_regs(regs, NULL);
196}
197
198/*
199 * Re-start a thread when doing execve()
200 */
201void
202start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
203{
204 set_fs(USER_DS);
205 regs->pc = pc;
206 regs->ps = 8;
207 wrusp(sp);
208}
Al Virocff52da2006-10-11 17:40:22 +0100209EXPORT_SYMBOL(start_thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211/*
212 * Free current thread data structures etc..
213 */
214void
215exit_thread(void)
216{
217}
218
219void
220flush_thread(void)
221{
222 /* Arrange for each exec'ed process to start off with a clean slate
223 with respect to the FPU. This is all exceptions disabled. */
224 current_thread_info()->ieee_state = 0;
225 wrfpcr(FPCR_DYN_NORMAL | ieee_swcr_to_fpcr(0));
226
227 /* Clean slate for TLS. */
228 current_thread_info()->pcb.unique = 0;
229}
230
231void
232release_thread(struct task_struct *dead_task)
233{
234}
235
236/*
237 * "alpha_clone()".. By the time we get here, the
238 * non-volatile registers have also been saved on the
239 * stack. We do some ugly pointer stuff here.. (see
240 * also copy_thread)
241 *
242 * Notice that "fork()" is implemented in terms of clone,
243 * with parameters (SIGCHLD, 0).
244 */
245int
246alpha_clone(unsigned long clone_flags, unsigned long usp,
247 int __user *parent_tid, int __user *child_tid,
248 unsigned long tls_value, struct pt_regs *regs)
249{
250 if (!usp)
251 usp = rdusp();
252
253 return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid);
254}
255
256int
257alpha_vfork(struct pt_regs *regs)
258{
259 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(),
260 regs, 0, NULL, NULL);
261}
262
263/*
264 * Copy an alpha thread..
265 *
266 * Note the "stack_offset" stuff: when returning to kernel mode, we need
267 * to have some extra stack-space for the kernel stack that still exists
268 * after the "ret_from_fork". When returning to user mode, we only want
269 * the space needed by the syscall stack frame (ie "struct pt_regs").
270 * Use the passed "regs" pointer to determine how much space we need
271 * for a kernel fork().
272 */
273
274int
275copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
276 unsigned long unused,
277 struct task_struct * p, struct pt_regs * regs)
278{
279 extern void ret_from_fork(void);
280
Al Viro27f45132006-01-12 01:05:36 -0800281 struct thread_info *childti = task_thread_info(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 struct pt_regs * childregs;
283 struct switch_stack * childstack, *stack;
284 unsigned long stack_offset, settls;
285
286 stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
287 if (!(regs->ps & 8))
288 stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
289 childregs = (struct pt_regs *)
Al Viro27f45132006-01-12 01:05:36 -0800290 (stack_offset + PAGE_SIZE + task_stack_page(p));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 *childregs = *regs;
293 settls = regs->r20;
294 childregs->r0 = 0;
295 childregs->r19 = 0;
296 childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
297 regs->r20 = 0;
298 stack = ((struct switch_stack *) regs) - 1;
299 childstack = ((struct switch_stack *) childregs) - 1;
300 *childstack = *stack;
301 childstack->r26 = (unsigned long) ret_from_fork;
302 childti->pcb.usp = usp;
303 childti->pcb.ksp = (unsigned long) childstack;
304 childti->pcb.flags = 1; /* set FEN, clear everything else */
305
306 /* Set a new TLS for the child thread? Peek back into the
307 syscall arguments that we saved on syscall entry. Oops,
308 except we'd have clobbered it with the parent/child set
309 of r20. Read the saved copy. */
310 /* Note: if CLONE_SETTLS is not set, then we must inherit the
311 value from the parent, which will have been set by the block
312 copy in dup_task_struct. This is non-intuitive, but is
313 required for proper operation in the case of a threaded
314 application calling fork. */
315 if (clone_flags & CLONE_SETTLS)
316 childti->pcb.unique = settls;
317
318 return 0;
319}
320
321/*
322 * Fill in the user structure for an ECOFF core dump.
323 */
324void
325dump_thread(struct pt_regs * pt, struct user * dump)
326{
327 /* switch stack follows right below pt_regs: */
328 struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
329
330 dump->magic = CMAGIC;
331 dump->start_code = current->mm->start_code;
332 dump->start_data = current->mm->start_data;
333 dump->start_stack = rdusp() & ~(PAGE_SIZE - 1);
334 dump->u_tsize = ((current->mm->end_code - dump->start_code)
335 >> PAGE_SHIFT);
336 dump->u_dsize = ((current->mm->brk + PAGE_SIZE-1 - dump->start_data)
337 >> PAGE_SHIFT);
338 dump->u_ssize = (current->mm->start_stack - dump->start_stack
339 + PAGE_SIZE-1) >> PAGE_SHIFT;
340
341 /*
342 * We store the registers in an order/format that is
343 * compatible with DEC Unix/OSF/1 as this makes life easier
344 * for gdb.
345 */
346 dump->regs[EF_V0] = pt->r0;
347 dump->regs[EF_T0] = pt->r1;
348 dump->regs[EF_T1] = pt->r2;
349 dump->regs[EF_T2] = pt->r3;
350 dump->regs[EF_T3] = pt->r4;
351 dump->regs[EF_T4] = pt->r5;
352 dump->regs[EF_T5] = pt->r6;
353 dump->regs[EF_T6] = pt->r7;
354 dump->regs[EF_T7] = pt->r8;
355 dump->regs[EF_S0] = sw->r9;
356 dump->regs[EF_S1] = sw->r10;
357 dump->regs[EF_S2] = sw->r11;
358 dump->regs[EF_S3] = sw->r12;
359 dump->regs[EF_S4] = sw->r13;
360 dump->regs[EF_S5] = sw->r14;
361 dump->regs[EF_S6] = sw->r15;
362 dump->regs[EF_A3] = pt->r19;
363 dump->regs[EF_A4] = pt->r20;
364 dump->regs[EF_A5] = pt->r21;
365 dump->regs[EF_T8] = pt->r22;
366 dump->regs[EF_T9] = pt->r23;
367 dump->regs[EF_T10] = pt->r24;
368 dump->regs[EF_T11] = pt->r25;
369 dump->regs[EF_RA] = pt->r26;
370 dump->regs[EF_T12] = pt->r27;
371 dump->regs[EF_AT] = pt->r28;
372 dump->regs[EF_SP] = rdusp();
373 dump->regs[EF_PS] = pt->ps;
374 dump->regs[EF_PC] = pt->pc;
375 dump->regs[EF_GP] = pt->gp;
376 dump->regs[EF_A0] = pt->r16;
377 dump->regs[EF_A1] = pt->r17;
378 dump->regs[EF_A2] = pt->r18;
379 memcpy((char *)dump->regs + EF_SIZE, sw->fp, 32 * 8);
380}
Al Virocff52da2006-10-11 17:40:22 +0100381EXPORT_SYMBOL(dump_thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
383/*
384 * Fill in the user structure for a ELF core dump.
385 */
386void
387dump_elf_thread(elf_greg_t *dest, struct pt_regs *pt, struct thread_info *ti)
388{
389 /* switch stack follows right below pt_regs: */
390 struct switch_stack * sw = ((struct switch_stack *) pt) - 1;
391
392 dest[ 0] = pt->r0;
393 dest[ 1] = pt->r1;
394 dest[ 2] = pt->r2;
395 dest[ 3] = pt->r3;
396 dest[ 4] = pt->r4;
397 dest[ 5] = pt->r5;
398 dest[ 6] = pt->r6;
399 dest[ 7] = pt->r7;
400 dest[ 8] = pt->r8;
401 dest[ 9] = sw->r9;
402 dest[10] = sw->r10;
403 dest[11] = sw->r11;
404 dest[12] = sw->r12;
405 dest[13] = sw->r13;
406 dest[14] = sw->r14;
407 dest[15] = sw->r15;
408 dest[16] = pt->r16;
409 dest[17] = pt->r17;
410 dest[18] = pt->r18;
411 dest[19] = pt->r19;
412 dest[20] = pt->r20;
413 dest[21] = pt->r21;
414 dest[22] = pt->r22;
415 dest[23] = pt->r23;
416 dest[24] = pt->r24;
417 dest[25] = pt->r25;
418 dest[26] = pt->r26;
419 dest[27] = pt->r27;
420 dest[28] = pt->r28;
421 dest[29] = pt->gp;
422 dest[30] = rdusp();
423 dest[31] = pt->pc;
424
425 /* Once upon a time this was the PS value. Which is stupid
426 since that is always 8 for usermode. Usurped for the more
427 useful value of the thread's UNIQUE field. */
428 dest[32] = ti->pcb.unique;
429}
Al Virocff52da2006-10-11 17:40:22 +0100430EXPORT_SYMBOL(dump_elf_thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
432int
433dump_elf_task(elf_greg_t *dest, struct task_struct *task)
434{
akpm@osdl.orge52f4ca2006-01-12 01:05:37 -0800435 dump_elf_thread(dest, task_pt_regs(task), task_thread_info(task));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 return 1;
437}
Al Virocff52da2006-10-11 17:40:22 +0100438EXPORT_SYMBOL(dump_elf_task);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440int
441dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
442{
akpm@osdl.orge52f4ca2006-01-12 01:05:37 -0800443 struct switch_stack *sw = (struct switch_stack *)task_pt_regs(task) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 memcpy(dest, sw->fp, 32 * 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 return 1;
446}
Al Virocff52da2006-10-11 17:40:22 +0100447EXPORT_SYMBOL(dump_elf_task_fp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
449/*
450 * sys_execve() executes a new program.
451 */
452asmlinkage int
453do_sys_execve(char __user *ufilename, char __user * __user *argv,
454 char __user * __user *envp, struct pt_regs *regs)
455{
456 int error;
457 char *filename;
458
459 filename = getname(ufilename);
460 error = PTR_ERR(filename);
461 if (IS_ERR(filename))
462 goto out;
463 error = do_execve(filename, argv, envp, regs);
464 putname(filename);
465out:
466 return error;
467}
468
469/*
470 * Return saved PC of a blocked thread. This assumes the frame
471 * pointer is the 6th saved long on the kernel stack and that the
472 * saved return address is the first long in the frame. This all
473 * holds provided the thread blocked through a call to schedule() ($15
474 * is the frame pointer in schedule() and $15 is saved at offset 48 by
475 * entry.S:do_switch_stack).
476 *
477 * Under heavy swap load I've seen this lose in an ugly way. So do
478 * some extra sanity checking on the ranges we expect these pointers
479 * to be in so that we can fail gracefully. This is just for ps after
480 * all. -- r~
481 */
482
483unsigned long
Ingo Molnar36c8b582006-07-03 00:25:41 -0700484thread_saved_pc(struct task_struct *t)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485{
Al Viro27f45132006-01-12 01:05:36 -0800486 unsigned long base = (unsigned long)task_stack_page(t);
Al Viro37bfbaf2006-01-12 01:05:36 -0800487 unsigned long fp, sp = task_thread_info(t)->pcb.ksp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
489 if (sp > base && sp+6*8 < base + 16*1024) {
490 fp = ((unsigned long*)sp)[6];
491 if (fp > sp && fp < base + 16*1024)
492 return *(unsigned long *)fp;
493 }
494
495 return 0;
496}
497
498unsigned long
499get_wchan(struct task_struct *p)
500{
501 unsigned long schedule_frame;
502 unsigned long pc;
503 if (!p || p == current || p->state == TASK_RUNNING)
504 return 0;
505 /*
506 * This one depends on the frame size of schedule(). Do a
507 * "disass schedule" in gdb to find the frame size. Also, the
508 * code assumes that sleep_on() follows immediately after
509 * interruptible_sleep_on() and that add_timer() follows
510 * immediately after interruptible_sleep(). Ugly, isn't it?
511 * Maybe adding a wchan field to task_struct would be better,
512 * after all...
513 */
514
515 pc = thread_saved_pc(p);
516 if (in_sched_functions(pc)) {
Al Viro37bfbaf2006-01-12 01:05:36 -0800517 schedule_frame = ((unsigned long *)task_thread_info(p)->pcb.ksp)[6];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 return ((unsigned long *)schedule_frame)[12];
519 }
520 return pc;
521}