ARM: 5868/1: ARM: fix "BUG: using smp_processor_id() in preemptible code"
[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/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/delay.h>
22 #include <linux/reboot.h>
23 #include <linux/interrupt.h>
24 #include <linux/kallsyms.h>
25 #include <linux/init.h>
26 #include <linux/cpu.h>
27 #include <linux/elfcore.h>
28 #include <linux/pm.h>
29 #include <linux/tick.h>
30 #include <linux/utsname.h>
31 #include <linux/uaccess.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/stacktrace.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 static const char *isa_modes[] = {
48   "ARM" , "Thumb" , "Jazelle", "ThumbEE"
49 };
50
51 extern void setup_mm_for_reboot(char mode);
52
53 static volatile int hlt_counter;
54
55 #include <mach/system.h>
56
57 void disable_hlt(void)
58 {
59         hlt_counter++;
60 }
61
62 EXPORT_SYMBOL(disable_hlt);
63
64 void enable_hlt(void)
65 {
66         hlt_counter--;
67 }
68
69 EXPORT_SYMBOL(enable_hlt);
70
71 static int __init nohlt_setup(char *__unused)
72 {
73         hlt_counter = 1;
74         return 1;
75 }
76
77 static int __init hlt_setup(char *__unused)
78 {
79         hlt_counter = 0;
80         return 1;
81 }
82
83 __setup("nohlt", nohlt_setup);
84 __setup("hlt", hlt_setup);
85
86 void arm_machine_restart(char mode, const char *cmd)
87 {
88         /*
89          * Clean and disable cache, and turn off interrupts
90          */
91         cpu_proc_fin();
92
93         /*
94          * Tell the mm system that we are going to reboot -
95          * we may need it to insert some 1:1 mappings so that
96          * soft boot works.
97          */
98         setup_mm_for_reboot(mode);
99
100         /*
101          * Now call the architecture specific reboot code.
102          */
103         arch_reset(mode, cmd);
104
105         /*
106          * Whoops - the architecture was unable to reboot.
107          * Tell the user!
108          */
109         mdelay(1000);
110         printk("Reboot failed -- System halted\n");
111         while (1);
112 }
113
114 /*
115  * Function pointers to optional machine specific functions
116  */
117 void (*pm_power_off)(void);
118 EXPORT_SYMBOL(pm_power_off);
119
120 void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
121 EXPORT_SYMBOL_GPL(arm_pm_restart);
122
123
124 /*
125  * This is our default idle handler.  We need to disable
126  * interrupts here to ensure we don't miss a wakeup call.
127  */
128 static void default_idle(void)
129 {
130         if (!need_resched())
131                 arch_idle();
132         local_irq_enable();
133 }
134
135 void (*pm_idle)(void) = default_idle;
136 EXPORT_SYMBOL(pm_idle);
137
138 /*
139  * The idle thread, has rather strange semantics for calling pm_idle,
140  * but this is what x86 does and we need to do the same, so that
141  * things like cpuidle get called in the same way.  The only difference
142  * is that we always respect 'hlt_counter' to prevent low power idle.
143  */
144 void cpu_idle(void)
145 {
146         local_fiq_enable();
147
148         /* endless idle loop with no priority at all */
149         while (1) {
150                 tick_nohz_stop_sched_tick(1);
151                 leds_event(led_idle_start);
152                 while (!need_resched()) {
153 #ifdef CONFIG_HOTPLUG_CPU
154                         if (cpu_is_offline(smp_processor_id()))
155                                 cpu_die();
156 #endif
157
158                         local_irq_disable();
159                         if (hlt_counter) {
160                                 local_irq_enable();
161                                 cpu_relax();
162                         } else {
163                                 stop_critical_timings();
164                                 pm_idle();
165                                 start_critical_timings();
166                                 /*
167                                  * This will eventually be removed - pm_idle
168                                  * functions should always return with IRQs
169                                  * enabled.
170                                  */
171                                 WARN_ON(irqs_disabled());
172                                 local_irq_enable();
173                         }
174                 }
175                 leds_event(led_idle_end);
176                 tick_nohz_restart_sched_tick();
177                 preempt_enable_no_resched();
178                 schedule();
179                 preempt_disable();
180         }
181 }
182
183 static char reboot_mode = 'h';
184
185 int __init reboot_setup(char *str)
186 {
187         reboot_mode = str[0];
188         return 1;
189 }
190
191 __setup("reboot=", reboot_setup);
192
193 void machine_halt(void)
194 {
195 }
196
197
198 void machine_power_off(void)
199 {
200         if (pm_power_off)
201                 pm_power_off();
202 }
203
204 void machine_restart(char *cmd)
205 {
206         arm_pm_restart(reboot_mode, cmd);
207 }
208
209 void __show_regs(struct pt_regs *regs)
210 {
211         unsigned long flags;
212         char buf[64];
213
214         printk("CPU: %d    %s  (%s %.*s)\n",
215                 raw_smp_processor_id(), print_tainted(),
216                 init_utsname()->release,
217                 (int)strcspn(init_utsname()->version, " "),
218                 init_utsname()->version);
219         print_symbol("PC is at %s\n", instruction_pointer(regs));
220         print_symbol("LR is at %s\n", regs->ARM_lr);
221         printk("pc : [<%08lx>]    lr : [<%08lx>]    psr: %08lx\n"
222                "sp : %08lx  ip : %08lx  fp : %08lx\n",
223                 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
224                 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
225         printk("r10: %08lx  r9 : %08lx  r8 : %08lx\n",
226                 regs->ARM_r10, regs->ARM_r9,
227                 regs->ARM_r8);
228         printk("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
229                 regs->ARM_r7, regs->ARM_r6,
230                 regs->ARM_r5, regs->ARM_r4);
231         printk("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
232                 regs->ARM_r3, regs->ARM_r2,
233                 regs->ARM_r1, regs->ARM_r0);
234
235         flags = regs->ARM_cpsr;
236         buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
237         buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
238         buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
239         buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
240         buf[4] = '\0';
241
242         printk("Flags: %s  IRQs o%s  FIQs o%s  Mode %s  ISA %s  Segment %s\n",
243                 buf, interrupts_enabled(regs) ? "n" : "ff",
244                 fast_interrupts_enabled(regs) ? "n" : "ff",
245                 processor_modes[processor_mode(regs)],
246                 isa_modes[isa_mode(regs)],
247                 get_fs() == get_ds() ? "kernel" : "user");
248 #ifdef CONFIG_CPU_CP15
249         {
250                 unsigned int ctrl;
251
252                 buf[0] = '\0';
253 #ifdef CONFIG_CPU_CP15_MMU
254                 {
255                         unsigned int transbase, dac;
256                         asm("mrc p15, 0, %0, c2, c0\n\t"
257                             "mrc p15, 0, %1, c3, c0\n"
258                             : "=r" (transbase), "=r" (dac));
259                         snprintf(buf, sizeof(buf), "  Table: %08x  DAC: %08x",
260                                 transbase, dac);
261                 }
262 #endif
263                 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
264
265                 printk("Control: %08x%s\n", ctrl, buf);
266         }
267 #endif
268 }
269
270 void show_regs(struct pt_regs * regs)
271 {
272         printk("\n");
273         printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
274         __show_regs(regs);
275         __backtrace();
276 }
277
278 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
279
280 EXPORT_SYMBOL_GPL(thread_notify_head);
281
282 /*
283  * Free current thread data structures etc..
284  */
285 void exit_thread(void)
286 {
287         thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
288 }
289
290 void flush_thread(void)
291 {
292         struct thread_info *thread = current_thread_info();
293         struct task_struct *tsk = current;
294
295         memset(thread->used_cp, 0, sizeof(thread->used_cp));
296         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
297         memset(&thread->fpstate, 0, sizeof(union fp_state));
298
299         thread_notify(THREAD_NOTIFY_FLUSH, thread);
300 }
301
302 void release_thread(struct task_struct *dead_task)
303 {
304 }
305
306 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
307
308 int
309 copy_thread(unsigned long clone_flags, unsigned long stack_start,
310             unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
311 {
312         struct thread_info *thread = task_thread_info(p);
313         struct pt_regs *childregs = task_pt_regs(p);
314
315         *childregs = *regs;
316         childregs->ARM_r0 = 0;
317         childregs->ARM_sp = stack_start;
318
319         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
320         thread->cpu_context.sp = (unsigned long)childregs;
321         thread->cpu_context.pc = (unsigned long)ret_from_fork;
322
323         if (clone_flags & CLONE_SETTLS)
324                 thread->tp_value = regs->ARM_r3;
325
326         return 0;
327 }
328
329 /*
330  * Fill in the task's elfregs structure for a core dump.
331  */
332 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
333 {
334         elf_core_copy_regs(elfregs, task_pt_regs(t));
335         return 1;
336 }
337
338 /*
339  * fill in the fpe structure for a core dump...
340  */
341 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
342 {
343         struct thread_info *thread = current_thread_info();
344         int used_math = thread->used_cp[1] | thread->used_cp[2];
345
346         if (used_math)
347                 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
348
349         return used_math != 0;
350 }
351 EXPORT_SYMBOL(dump_fpu);
352
353 /*
354  * Shuffle the argument into the correct register before calling the
355  * thread function.  r1 is the thread argument, r2 is the pointer to
356  * the thread function, and r3 points to the exit function.
357  */
358 extern void kernel_thread_helper(void);
359 asm(    ".section .text\n"
360 "       .align\n"
361 "       .type   kernel_thread_helper, #function\n"
362 "kernel_thread_helper:\n"
363 "       mov     r0, r1\n"
364 "       mov     lr, r3\n"
365 "       mov     pc, r2\n"
366 "       .size   kernel_thread_helper, . - kernel_thread_helper\n"
367 "       .previous");
368
369 #ifdef CONFIG_ARM_UNWIND
370 extern void kernel_thread_exit(long code);
371 asm(    ".section .text\n"
372 "       .align\n"
373 "       .type   kernel_thread_exit, #function\n"
374 "kernel_thread_exit:\n"
375 "       .fnstart\n"
376 "       .cantunwind\n"
377 "       bl      do_exit\n"
378 "       nop\n"
379 "       .fnend\n"
380 "       .size   kernel_thread_exit, . - kernel_thread_exit\n"
381 "       .previous");
382 #else
383 #define kernel_thread_exit      do_exit
384 #endif
385
386 /*
387  * Create a kernel thread.
388  */
389 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
390 {
391         struct pt_regs regs;
392
393         memset(&regs, 0, sizeof(regs));
394
395         regs.ARM_r1 = (unsigned long)arg;
396         regs.ARM_r2 = (unsigned long)fn;
397         regs.ARM_r3 = (unsigned long)kernel_thread_exit;
398         regs.ARM_pc = (unsigned long)kernel_thread_helper;
399         regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
400
401         return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
402 }
403 EXPORT_SYMBOL(kernel_thread);
404
405 unsigned long get_wchan(struct task_struct *p)
406 {
407         struct stackframe frame;
408         int count = 0;
409         if (!p || p == current || p->state == TASK_RUNNING)
410                 return 0;
411
412         frame.fp = thread_saved_fp(p);
413         frame.sp = thread_saved_sp(p);
414         frame.lr = 0;                   /* recovered from the stack */
415         frame.pc = thread_saved_pc(p);
416         do {
417                 int ret = unwind_frame(&frame);
418                 if (ret < 0)
419                         return 0;
420                 if (!in_sched_functions(frame.pc))
421                         return frame.pc;
422         } while (count ++ < 16);
423         return 0;
424 }