Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6.git] / arch / arm / kernel / process.c
1 /*
2  *  linux/arch/arm/kernel/process.c
3  *
4  *  Copyright (C) 1996-2000 Russell King - Converted to ARM.
5  *  Original Copyright (C) 1995  Linus Torvalds
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <stdarg.h>
12
13 #include <linux/config.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/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/delay.h>
25 #include <linux/reboot.h>
26 #include <linux/interrupt.h>
27 #include <linux/kallsyms.h>
28 #include <linux/init.h>
29 #include <linux/cpu.h>
30
31 #include <asm/system.h>
32 #include <asm/io.h>
33 #include <asm/leds.h>
34 #include <asm/processor.h>
35 #include <asm/uaccess.h>
36 #include <asm/mach/time.h>
37
38 extern const char *processor_modes[];
39 extern void setup_mm_for_reboot(char mode);
40
41 static volatile int hlt_counter;
42
43 #include <asm/arch/system.h>
44
45 void disable_hlt(void)
46 {
47         hlt_counter++;
48 }
49
50 EXPORT_SYMBOL(disable_hlt);
51
52 void enable_hlt(void)
53 {
54         hlt_counter--;
55 }
56
57 EXPORT_SYMBOL(enable_hlt);
58
59 static int __init nohlt_setup(char *__unused)
60 {
61         hlt_counter = 1;
62         return 1;
63 }
64
65 static int __init hlt_setup(char *__unused)
66 {
67         hlt_counter = 0;
68         return 1;
69 }
70
71 __setup("nohlt", nohlt_setup);
72 __setup("hlt", hlt_setup);
73
74 /*
75  * The following aren't currently used.
76  */
77 void (*pm_idle)(void);
78 EXPORT_SYMBOL(pm_idle);
79
80 void (*pm_power_off)(void);
81 EXPORT_SYMBOL(pm_power_off);
82
83 /*
84  * This is our default idle handler.  We need to disable
85  * interrupts here to ensure we don't miss a wakeup call.
86  */
87 void default_idle(void)
88 {
89         if (hlt_counter)
90                 cpu_relax();
91         else {
92                 local_irq_disable();
93                 if (!need_resched()) {
94                         timer_dyn_reprogram();
95                         arch_idle();
96                 }
97                 local_irq_enable();
98         }
99 }
100
101 /*
102  * The idle thread.  We try to conserve power, while trying to keep
103  * overall latency low.  The architecture specific idle is passed
104  * a value to indicate the level of "idleness" of the system.
105  */
106 void cpu_idle(void)
107 {
108         local_fiq_enable();
109
110         /* endless idle loop with no priority at all */
111         while (1) {
112                 void (*idle)(void) = pm_idle;
113
114 #ifdef CONFIG_HOTPLUG_CPU
115                 if (cpu_is_offline(smp_processor_id())) {
116                         leds_event(led_idle_start);
117                         cpu_die();
118                 }
119 #endif
120
121                 if (!idle)
122                         idle = default_idle;
123                 leds_event(led_idle_start);
124                 while (!need_resched())
125                         idle();
126                 leds_event(led_idle_end);
127                 preempt_enable_no_resched();
128                 schedule();
129                 preempt_disable();
130         }
131 }
132
133 static char reboot_mode = 'h';
134
135 int __init reboot_setup(char *str)
136 {
137         reboot_mode = str[0];
138         return 1;
139 }
140
141 __setup("reboot=", reboot_setup);
142
143 void machine_halt(void)
144 {
145 }
146
147
148 void machine_power_off(void)
149 {
150         if (pm_power_off)
151                 pm_power_off();
152 }
153
154
155 void machine_restart(char * __unused)
156 {
157         /*
158          * Clean and disable cache, and turn off interrupts
159          */
160         cpu_proc_fin();
161
162         /*
163          * Tell the mm system that we are going to reboot -
164          * we may need it to insert some 1:1 mappings so that
165          * soft boot works.
166          */
167         setup_mm_for_reboot(reboot_mode);
168
169         /*
170          * Now call the architecture specific reboot code.
171          */
172         arch_reset(reboot_mode);
173
174         /*
175          * Whoops - the architecture was unable to reboot.
176          * Tell the user!
177          */
178         mdelay(1000);
179         printk("Reboot failed -- System halted\n");
180         while (1);
181 }
182
183 void __show_regs(struct pt_regs *regs)
184 {
185         unsigned long flags = condition_codes(regs);
186
187         printk("CPU: %d\n", smp_processor_id());
188         print_symbol("PC is at %s\n", instruction_pointer(regs));
189         print_symbol("LR is at %s\n", regs->ARM_lr);
190         printk("pc : [<%08lx>]    lr : [<%08lx>]    %s\n"
191                "sp : %08lx  ip : %08lx  fp : %08lx\n",
192                 instruction_pointer(regs),
193                 regs->ARM_lr, print_tainted(), regs->ARM_sp,
194                 regs->ARM_ip, regs->ARM_fp);
195         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
196                 regs->ARM_r10, regs->ARM_r9,
197                 regs->ARM_r8);
198         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
199                 regs->ARM_r7, regs->ARM_r6,
200                 regs->ARM_r5, regs->ARM_r4);
201         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
202                 regs->ARM_r3, regs->ARM_r2,
203                 regs->ARM_r1, regs->ARM_r0);
204         printk("Flags: %c%c%c%c",
205                 flags & PSR_N_BIT ? 'N' : 'n',
206                 flags & PSR_Z_BIT ? 'Z' : 'z',
207                 flags & PSR_C_BIT ? 'C' : 'c',
208                 flags & PSR_V_BIT ? 'V' : 'v');
209         printk("  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
210                 interrupts_enabled(regs) ? "n" : "ff",
211                 fast_interrupts_enabled(regs) ? "n" : "ff",
212                 processor_modes[processor_mode(regs)],
213                 thumb_mode(regs) ? " (T)" : "",
214                 get_fs() == get_ds() ? "kernel" : "user");
215         {
216                 unsigned int ctrl, transbase, dac;
217                   __asm__ (
218                 "       mrc p15, 0, %0, c1, c0\n"
219                 "       mrc p15, 0, %1, c2, c0\n"
220                 "       mrc p15, 0, %2, c3, c0\n"
221                 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
222                 printk("Control: %04X  Table: %08X  DAC: %08X\n",
223                         ctrl, transbase, dac);
224         }
225 }
226
227 void show_regs(struct pt_regs * regs)
228 {
229         printk("\n");
230         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
231         __show_regs(regs);
232         __backtrace();
233 }
234
235 void show_fpregs(struct user_fp *regs)
236 {
237         int i;
238
239         for (i = 0; i < 8; i++) {
240                 unsigned long *p;
241                 char type;
242
243                 p = (unsigned long *)(regs->fpregs + i);
244
245                 switch (regs->ftype[i]) {
246                         case 1: type = 'f'; break;
247                         case 2: type = 'd'; break;
248                         case 3: type = 'e'; break;
249                         default: type = '?'; break;
250                 }
251                 if (regs->init_flag)
252                         type = '?';
253
254                 printk("  f%d(%c): %08lx %08lx %08lx%c",
255                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
256         }
257                         
258
259         printk("FPSR: %08lx FPCR: %08lx\n",
260                 (unsigned long)regs->fpsr,
261                 (unsigned long)regs->fpcr);
262 }
263
264 /*
265  * Task structure and kernel stack allocation.
266  */
267 static unsigned long *thread_info_head;
268 static unsigned int nr_thread_info;
269
270 #define EXTRA_TASK_STRUCT       4
271
272 struct thread_info *alloc_thread_info(struct task_struct *task)
273 {
274         struct thread_info *thread = NULL;
275
276         if (EXTRA_TASK_STRUCT) {
277                 unsigned long *p = thread_info_head;
278
279                 if (p) {
280                         thread_info_head = (unsigned long *)p[0];
281                         nr_thread_info -= 1;
282                 }
283                 thread = (struct thread_info *)p;
284         }
285
286         if (!thread)
287                 thread = (struct thread_info *)
288                            __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
289
290 #ifdef CONFIG_DEBUG_STACK_USAGE
291         /*
292          * The stack must be cleared if you want SYSRQ-T to
293          * give sensible stack usage information
294          */
295         if (thread)
296                 memzero(thread, THREAD_SIZE);
297 #endif
298         return thread;
299 }
300
301 void free_thread_info(struct thread_info *thread)
302 {
303         if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) {
304                 unsigned long *p = (unsigned long *)thread;
305                 p[0] = (unsigned long)thread_info_head;
306                 thread_info_head = p;
307                 nr_thread_info += 1;
308         } else
309                 free_pages((unsigned long)thread, THREAD_SIZE_ORDER);
310 }
311
312 /*
313  * Free current thread data structures etc..
314  */
315 void exit_thread(void)
316 {
317 }
318
319 static void default_fp_init(union fp_state *fp)
320 {
321         memset(fp, 0, sizeof(union fp_state));
322 }
323
324 void (*fp_init)(union fp_state *) = default_fp_init;
325 EXPORT_SYMBOL(fp_init);
326
327 void flush_thread(void)
328 {
329         struct thread_info *thread = current_thread_info();
330         struct task_struct *tsk = current;
331
332         memset(thread->used_cp, 0, sizeof(thread->used_cp));
333         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
334 #if defined(CONFIG_IWMMXT)
335         iwmmxt_task_release(thread);
336 #endif
337         fp_init(&thread->fpstate);
338 #if defined(CONFIG_VFP)
339         vfp_flush_thread(&thread->vfpstate);
340 #endif
341 }
342
343 void release_thread(struct task_struct *dead_task)
344 {
345 #if defined(CONFIG_VFP)
346         vfp_release_thread(&dead_task->thread_info->vfpstate);
347 #endif
348 #if defined(CONFIG_IWMMXT)
349         iwmmxt_task_release(dead_task->thread_info);
350 #endif
351 }
352
353 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
354
355 int
356 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
357             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
358 {
359         struct thread_info *thread = p->thread_info;
360         struct pt_regs *childregs;
361
362         childregs = (void *)thread + THREAD_START_SP - sizeof(*regs);
363         *childregs = *regs;
364         childregs->ARM_r0 = 0;
365         childregs->ARM_sp = stack_start;
366
367         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
368         thread->cpu_context.sp = (unsigned long)childregs;
369         thread->cpu_context.pc = (unsigned long)ret_from_fork;
370
371         if (clone_flags & CLONE_SETTLS)
372                 thread->tp_value = regs->ARM_r3;
373
374         return 0;
375 }
376
377 /*
378  * fill in the fpe structure for a core dump...
379  */
380 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
381 {
382         struct thread_info *thread = current_thread_info();
383         int used_math = thread->used_cp[1] | thread->used_cp[2];
384
385         if (used_math)
386                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
387
388         return used_math != 0;
389 }
390 EXPORT_SYMBOL(dump_fpu);
391
392 /*
393  * fill in the user structure for a core dump..
394  */
395 void dump_thread(struct pt_regs * regs, struct user * dump)
396 {
397         struct task_struct *tsk = current;
398
399         dump->magic = CMAGIC;
400         dump->start_code = tsk->mm->start_code;
401         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
402
403         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
404         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
405         dump->u_ssize = 0;
406
407         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
408         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
409         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
410         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
411         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
412
413         if (dump->start_stack < 0x04000000)
414                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
415
416         dump->regs = *regs;
417         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
418 }
419 EXPORT_SYMBOL(dump_thread);
420
421 /*
422  * Shuffle the argument into the correct register before calling the
423  * thread function.  r1 is the thread argument, r2 is the pointer to
424  * the thread function, and r3 points to the exit function.
425  */
426 extern void kernel_thread_helper(void);
427 asm(    ".section .text\n"
428 "       .align\n"
429 "       .type   kernel_thread_helper, #function\n"
430 "kernel_thread_helper:\n"
431 "       mov     r0, r1\n"
432 "       mov     lr, r3\n"
433 "       mov     pc, r2\n"
434 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
435 "       .previous");
436
437 /*
438  * Create a kernel thread.
439  */
440 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
441 {
442         struct pt_regs regs;
443
444         memset(&regs, 0, sizeof(regs));
445
446         regs.ARM_r1 = (unsigned long)arg;
447         regs.ARM_r2 = (unsigned long)fn;
448         regs.ARM_r3 = (unsigned long)do_exit;
449         regs.ARM_pc = (unsigned long)kernel_thread_helper;
450         regs.ARM_cpsr = SVC_MODE;
451
452         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
453 }
454 EXPORT_SYMBOL(kernel_thread);
455
456 unsigned long get_wchan(struct task_struct *p)
457 {
458         unsigned long fp, lr;
459         unsigned long stack_start, stack_end;
460         int count = 0;
461         if (!p || p == current || p->state == TASK_RUNNING)
462                 return 0;
463
464         stack_start = (unsigned long)(p->thread_info + 1);
465         stack_end = ((unsigned long)p->thread_info) + THREAD_SIZE;
466
467         fp = thread_saved_fp(p);
468         do {
469                 if (fp < stack_start || fp > stack_end)
470                         return 0;
471                 lr = pc_pointer (((unsigned long *)fp)[-1]);
472                 if (!in_sched_functions(lr))
473                         return lr;
474                 fp = *(unsigned long *) (fp - 12);
475         } while (count ++ < 16);
476         return 0;
477 }
478 EXPORT_SYMBOL(get_wchan);