Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-2.6] / 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/module.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/slab.h>
20 #include <linux/user.h>
21 #include <linux/a.out.h>
22 #include <linux/delay.h>
23 #include <linux/reboot.h>
24 #include <linux/interrupt.h>
25 #include <linux/kallsyms.h>
26 #include <linux/init.h>
27 #include <linux/cpu.h>
28 #include <linux/elfcore.h>
29 #include <linux/pm.h>
30 #include <linux/tick.h>
31 #include <linux/utsname.h>
32
33 #include <asm/leds.h>
34 #include <asm/processor.h>
35 #include <asm/system.h>
36 #include <asm/thread_notify.h>
37 #include <asm/uaccess.h>
38 #include <asm/mach/time.h>
39
40 static const char *processor_modes[] = {
41   "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
42   "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
43   "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
44   "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
45 };
46
47 extern void setup_mm_for_reboot(char mode);
48
49 static volatile int hlt_counter;
50
51 #include <asm/arch/system.h>
52
53 void disable_hlt(void)
54 {
55         hlt_counter++;
56 }
57
58 EXPORT_SYMBOL(disable_hlt);
59
60 void enable_hlt(void)
61 {
62         hlt_counter--;
63 }
64
65 EXPORT_SYMBOL(enable_hlt);
66
67 static int __init nohlt_setup(char *__unused)
68 {
69         hlt_counter = 1;
70         return 1;
71 }
72
73 static int __init hlt_setup(char *__unused)
74 {
75         hlt_counter = 0;
76         return 1;
77 }
78
79 __setup("nohlt", nohlt_setup);
80 __setup("hlt", hlt_setup);
81
82 void arm_machine_restart(char mode)
83 {
84         /*
85          * Clean and disable cache, and turn off interrupts
86          */
87         cpu_proc_fin();
88
89         /*
90          * Tell the mm system that we are going to reboot -
91          * we may need it to insert some 1:1 mappings so that
92          * soft boot works.
93          */
94         setup_mm_for_reboot(mode);
95
96         /*
97          * Now call the architecture specific reboot code.
98          */
99         arch_reset(mode);
100
101         /*
102          * Whoops - the architecture was unable to reboot.
103          * Tell the user!
104          */
105         mdelay(1000);
106         printk("Reboot failed -- System halted\n");
107         while (1);
108 }
109
110 /*
111  * Function pointers to optional machine specific functions
112  */
113 void (*pm_idle)(void);
114 EXPORT_SYMBOL(pm_idle);
115
116 void (*pm_power_off)(void);
117 EXPORT_SYMBOL(pm_power_off);
118
119 void (*arm_pm_restart)(char str) = arm_machine_restart;
120 EXPORT_SYMBOL_GPL(arm_pm_restart);
121
122
123 /*
124  * This is our default idle handler.  We need to disable
125  * interrupts here to ensure we don't miss a wakeup call.
126  */
127 static void default_idle(void)
128 {
129         if (hlt_counter)
130                 cpu_relax();
131         else {
132                 local_irq_disable();
133                 if (!need_resched()) {
134                         timer_dyn_reprogram();
135                         arch_idle();
136                 }
137                 local_irq_enable();
138         }
139 }
140
141 /*
142  * The idle thread.  We try to conserve power, while trying to keep
143  * overall latency low.  The architecture specific idle is passed
144  * a value to indicate the level of "idleness" of the system.
145  */
146 void cpu_idle(void)
147 {
148         local_fiq_enable();
149
150         /* endless idle loop with no priority at all */
151         while (1) {
152                 void (*idle)(void) = pm_idle;
153
154 #ifdef CONFIG_HOTPLUG_CPU
155                 if (cpu_is_offline(smp_processor_id())) {
156                         leds_event(led_idle_start);
157                         cpu_die();
158                 }
159 #endif
160
161                 if (!idle)
162                         idle = default_idle;
163                 leds_event(led_idle_start);
164                 tick_nohz_stop_sched_tick();
165                 while (!need_resched())
166                         idle();
167                 leds_event(led_idle_end);
168                 tick_nohz_restart_sched_tick();
169                 preempt_enable_no_resched();
170                 schedule();
171                 preempt_disable();
172         }
173 }
174
175 static char reboot_mode = 'h';
176
177 int __init reboot_setup(char *str)
178 {
179         reboot_mode = str[0];
180         return 1;
181 }
182
183 __setup("reboot=", reboot_setup);
184
185 void machine_halt(void)
186 {
187 }
188
189
190 void machine_power_off(void)
191 {
192         if (pm_power_off)
193                 pm_power_off();
194 }
195
196 void machine_restart(char * __unused)
197 {
198         arm_pm_restart(reboot_mode);
199 }
200
201 void __show_regs(struct pt_regs *regs)
202 {
203         unsigned long flags;
204         char buf[64];
205
206         printk("CPU: %d    %s  (%s %.*s)\n",
207                 smp_processor_id(), print_tainted(), init_utsname()->release,
208                 (int)strcspn(init_utsname()->version, " "),
209                 init_utsname()->version);
210         print_symbol("PC is at %s\n", instruction_pointer(regs));
211         print_symbol("LR is at %s\n", regs->ARM_lr);
212         printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
213                "sp : %08lx  ip : %08lx  fp : %08lx\n",
214                 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
215                 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
216         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
217                 regs->ARM_r10, regs->ARM_r9,
218                 regs->ARM_r8);
219         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
220                 regs->ARM_r7, regs->ARM_r6,
221                 regs->ARM_r5, regs->ARM_r4);
222         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
223                 regs->ARM_r3, regs->ARM_r2,
224                 regs->ARM_r1, regs->ARM_r0);
225
226         flags = regs->ARM_cpsr;
227         buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
228         buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
229         buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
230         buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
231         buf[4] = '\0';
232
233         printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s%s  Segment %s\n",
234                 buf, interrupts_enabled(regs) ? "n" : "ff",
235                 fast_interrupts_enabled(regs) ? "n" : "ff",
236                 processor_modes[processor_mode(regs)],
237                 thumb_mode(regs) ? " (T)" : "",
238                 get_fs() == get_ds() ? "kernel" : "user");
239 #ifdef CONFIG_CPU_CP15
240         {
241                 unsigned int ctrl;
242
243                 buf[0] = '\0';
244 #ifdef CONFIG_CPU_CP15_MMU
245                 {
246                         unsigned int transbase, dac;
247                         asm("mrc p15, 0, %0, c2, c0\n\t"
248                             "mrc p15, 0, %1, c3, c0\n"
249                             : "=r" (transbase), "=r" (dac));
250                         snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
251                                 transbase, dac);
252                 }
253 #endif
254                 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
255
256                 printk("Control: %08x%s\n", ctrl, buf);
257         }
258 #endif
259 }
260
261 void show_regs(struct pt_regs * regs)
262 {
263         printk("\n");
264         printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
265         __show_regs(regs);
266         __backtrace();
267 }
268
269 void show_fpregs(struct user_fp *regs)
270 {
271         int i;
272
273         for (i = 0; i < 8; i++) {
274                 unsigned long *p;
275                 char type;
276
277                 p = (unsigned long *)(regs->fpregs + i);
278
279                 switch (regs->ftype[i]) {
280                         case 1: type = 'f'; break;
281                         case 2: type = 'd'; break;
282                         case 3: type = 'e'; break;
283                         default: type = '?'; break;
284                 }
285                 if (regs->init_flag)
286                         type = '?';
287
288                 printk("  f%d(%c): %08lx %08lx %08lx%c",
289                         i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
290         }
291                         
292
293         printk("FPSR: %08lx FPCR: %08lx\n",
294                 (unsigned long)regs->fpsr,
295                 (unsigned long)regs->fpcr);
296 }
297
298 /*
299  * Free current thread data structures etc..
300  */
301 void exit_thread(void)
302 {
303 }
304
305 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
306
307 EXPORT_SYMBOL_GPL(thread_notify_head);
308
309 void flush_thread(void)
310 {
311         struct thread_info *thread = current_thread_info();
312         struct task_struct *tsk = current;
313
314         memset(thread->used_cp, 0, sizeof(thread->used_cp));
315         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
316         memset(&thread->fpstate, 0, sizeof(union fp_state));
317
318         thread_notify(THREAD_NOTIFY_FLUSH, thread);
319 }
320
321 void release_thread(struct task_struct *dead_task)
322 {
323         struct thread_info *thread = task_thread_info(dead_task);
324
325         thread_notify(THREAD_NOTIFY_RELEASE, thread);
326 }
327
328 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
329
330 int
331 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
332             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
333 {
334         struct thread_info *thread = task_thread_info(p);
335         struct pt_regs *childregs = task_pt_regs(p);
336
337         *childregs = *regs;
338         childregs->ARM_r0 = 0;
339         childregs->ARM_sp = stack_start;
340
341         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
342         thread->cpu_context.sp = (unsigned long)childregs;
343         thread->cpu_context.pc = (unsigned long)ret_from_fork;
344
345         if (clone_flags & CLONE_SETTLS)
346                 thread->tp_value = regs->ARM_r3;
347
348         return 0;
349 }
350
351 /*
352  * fill in the fpe structure for a core dump...
353  */
354 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
355 {
356         struct thread_info *thread = current_thread_info();
357         int used_math = thread->used_cp[1] | thread->used_cp[2];
358
359         if (used_math)
360                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
361
362         return used_math != 0;
363 }
364 EXPORT_SYMBOL(dump_fpu);
365
366 /*
367  * fill in the user structure for a core dump..
368  */
369 void dump_thread(struct pt_regs * regs, struct user * dump)
370 {
371         struct task_struct *tsk = current;
372
373         dump->magic = CMAGIC;
374         dump->start_code = tsk->mm->start_code;
375         dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
376
377         dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
378         dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
379         dump->u_ssize = 0;
380
381         dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
382         dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
383         dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
384         dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
385         dump->u_debugreg[4] = tsk->thread.debug.nsaved;
386
387         if (dump->start_stack < 0x04000000)
388                 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
389
390         dump->regs = *regs;
391         dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
392 }
393 EXPORT_SYMBOL(dump_thread);
394
395 /*
396  * Shuffle the argument into the correct register before calling the
397  * thread function.  r1 is the thread argument, r2 is the pointer to
398  * the thread function, and r3 points to the exit function.
399  */
400 extern void kernel_thread_helper(void);
401 asm(    ".section .text\n"
402 "       .align\n"
403 "       .type   kernel_thread_helper, #function\n"
404 "kernel_thread_helper:\n"
405 "       mov     r0, r1\n"
406 "       mov     lr, r3\n"
407 "       mov     pc, r2\n"
408 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
409 "       .previous");
410
411 /*
412  * Create a kernel thread.
413  */
414 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
415 {
416         struct pt_regs regs;
417
418         memset(&regs, 0, sizeof(regs));
419
420         regs.ARM_r1 = (unsigned long)arg;
421         regs.ARM_r2 = (unsigned long)fn;
422         regs.ARM_r3 = (unsigned long)do_exit;
423         regs.ARM_pc = (unsigned long)kernel_thread_helper;
424         regs.ARM_cpsr = SVC_MODE;
425
426         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
427 }
428 EXPORT_SYMBOL(kernel_thread);
429
430 unsigned long get_wchan(struct task_struct *p)
431 {
432         unsigned long fp, lr;
433         unsigned long stack_start, stack_end;
434         int count = 0;
435         if (!p || p == current || p->state == TASK_RUNNING)
436                 return 0;
437
438         stack_start = (unsigned long)end_of_stack(p);
439         stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
440
441         fp = thread_saved_fp(p);
442         do {
443                 if (fp < stack_start || fp > stack_end)
444                         return 0;
445                 lr = pc_pointer (((unsigned long *)fp)[-1]);
446                 if (!in_sched_functions(lr))
447                         return lr;
448                 fp = *(unsigned long *) (fp - 12);
449         } while (count ++ < 16);
450         return 0;
451 }