ARM: restart: only perform setup for restart when soft-restarting
[deliverable/linux.git] / arch / arm / kernel / process.c
CommitLineData
1da177e4
LT
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
ecea4ab6 13#include <linux/export.h>
1da177e4
LT
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>
1da177e4 19#include <linux/user.h>
1da177e4
LT
20#include <linux/delay.h>
21#include <linux/reboot.h>
22#include <linux/interrupt.h>
23#include <linux/kallsyms.h>
24#include <linux/init.h>
a054a811 25#include <linux/cpu.h>
84dff1a7 26#include <linux/elfcore.h>
74617fb6 27#include <linux/pm.h>
9e4559dd 28#include <linux/tick.h>
154c772e 29#include <linux/utsname.h>
33fa9b13 30#include <linux/uaccess.h>
990cb8ac 31#include <linux/random.h>
864232fa 32#include <linux/hw_breakpoint.h>
a0bfa137 33#include <linux/cpuidle.h>
1da177e4 34
9ca03a21 35#include <asm/cacheflush.h>
1da177e4
LT
36#include <asm/leds.h>
37#include <asm/processor.h>
78ff18a4 38#include <asm/system.h>
d6551e88 39#include <asm/thread_notify.h>
2d7c11bf 40#include <asm/stacktrace.h>
2ea83398 41#include <asm/mach/time.h>
1da177e4 42
c743f380
NP
43#ifdef CONFIG_CC_STACKPROTECTOR
44#include <linux/stackprotector.h>
45unsigned long __stack_chk_guard __read_mostly;
46EXPORT_SYMBOL(__stack_chk_guard);
47#endif
48
ae0a846e
RK
49static const char *processor_modes[] = {
50 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
51 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
52 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
53 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
54};
55
909d6c6c
GD
56static const char *isa_modes[] = {
57 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
58};
59
5aafec15 60extern void setup_mm_for_reboot(void);
1da177e4
LT
61
62static volatile int hlt_counter;
63
a09e64fb 64#include <mach/system.h>
1da177e4
LT
65
66void disable_hlt(void)
67{
68 hlt_counter++;
69}
70
71EXPORT_SYMBOL(disable_hlt);
72
73void enable_hlt(void)
74{
75 hlt_counter--;
76}
77
78EXPORT_SYMBOL(enable_hlt);
79
80static int __init nohlt_setup(char *__unused)
81{
82 hlt_counter = 1;
83 return 1;
84}
85
86static int __init hlt_setup(char *__unused)
87{
88 hlt_counter = 0;
89 return 1;
90}
91
92__setup("nohlt", nohlt_setup);
93__setup("hlt", hlt_setup);
94
e879c862 95void soft_restart(unsigned long addr)
74617fb6 96{
9ca03a21
RK
97 /* Disable interrupts first */
98 local_irq_disable();
99 local_fiq_disable();
74617fb6
RP
100
101 /*
102 * Tell the mm system that we are going to reboot -
103 * we may need it to insert some 1:1 mappings so that
104 * soft boot works.
105 */
5aafec15 106 setup_mm_for_reboot();
74617fb6 107
9ca03a21
RK
108 /* Clean and invalidate caches */
109 flush_cache_all();
110
111 /* Turn off caching */
112 cpu_proc_fin();
113
114 /* Push out any further dirty data, and ensure cache is empty */
115 flush_cache_all();
116
e879c862
RK
117 cpu_reset(addr);
118}
119
120void arm_machine_restart(char mode, const char *cmd)
121{
122 /* Disable interrupts first */
123 local_irq_disable();
124 local_fiq_disable();
125
126 /* Call the architecture specific reboot code. */
be093beb 127 arch_reset(mode, cmd);
74617fb6
RP
128}
129
1da177e4 130/*
74617fb6 131 * Function pointers to optional machine specific functions
1da177e4 132 */
1da177e4
LT
133void (*pm_power_off)(void);
134EXPORT_SYMBOL(pm_power_off);
135
be093beb 136void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
74617fb6
RP
137EXPORT_SYMBOL_GPL(arm_pm_restart);
138
c7b0aff4
KH
139static void do_nothing(void *unused)
140{
141}
142
143/*
144 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
145 * pm_idle and update to new pm_idle value. Required while changing pm_idle
146 * handler on SMP systems.
147 *
148 * Caller must have changed pm_idle to the new value before the call. Old
149 * pm_idle value will not be used by any CPU after the return of this function.
150 */
151void cpu_idle_wait(void)
152{
153 smp_mb();
154 /* kick all the CPUs so that they exit out of pm_idle */
155 smp_call_function(do_nothing, NULL, 1);
156}
157EXPORT_SYMBOL_GPL(cpu_idle_wait);
74617fb6 158
1da177e4
LT
159/*
160 * This is our default idle handler. We need to disable
161 * interrupts here to ensure we don't miss a wakeup call.
162 */
84dff1a7 163static void default_idle(void)
1da177e4 164{
9ccdac36
RK
165 if (!need_resched())
166 arch_idle();
167 local_irq_enable();
1da177e4
LT
168}
169
9ccdac36
RK
170void (*pm_idle)(void) = default_idle;
171EXPORT_SYMBOL(pm_idle);
172
1da177e4 173/*
9ccdac36
RK
174 * The idle thread, has rather strange semantics for calling pm_idle,
175 * but this is what x86 does and we need to do the same, so that
176 * things like cpuidle get called in the same way. The only difference
177 * is that we always respect 'hlt_counter' to prevent low power idle.
1da177e4
LT
178 */
179void cpu_idle(void)
180{
181 local_fiq_enable();
182
183 /* endless idle loop with no priority at all */
184 while (1) {
9ccdac36
RK
185 tick_nohz_stop_sched_tick(1);
186 leds_event(led_idle_start);
187 while (!need_resched()) {
a054a811 188#ifdef CONFIG_HOTPLUG_CPU
9ccdac36
RK
189 if (cpu_is_offline(smp_processor_id()))
190 cpu_die();
a054a811
RK
191#endif
192
9ccdac36
RK
193 local_irq_disable();
194 if (hlt_counter) {
195 local_irq_enable();
196 cpu_relax();
197 } else {
198 stop_critical_timings();
cbc158d6 199 if (cpuidle_idle_call())
a0bfa137 200 pm_idle();
9ccdac36
RK
201 start_critical_timings();
202 /*
203 * This will eventually be removed - pm_idle
204 * functions should always return with IRQs
205 * enabled.
206 */
207 WARN_ON(irqs_disabled());
208 local_irq_enable();
209 }
210 }
1da177e4 211 leds_event(led_idle_end);
9e4559dd 212 tick_nohz_restart_sched_tick();
5bfb5d69 213 preempt_enable_no_resched();
1da177e4 214 schedule();
5bfb5d69 215 preempt_disable();
1da177e4
LT
216 }
217}
218
219static char reboot_mode = 'h';
220
221int __init reboot_setup(char *str)
222{
223 reboot_mode = str[0];
224 return 1;
225}
226
227__setup("reboot=", reboot_setup);
228
3d3f78d7 229void machine_shutdown(void)
1da177e4 230{
3d3f78d7
RK
231#ifdef CONFIG_SMP
232 smp_send_stop();
233#endif
1da177e4
LT
234}
235
3d3f78d7
RK
236void machine_halt(void)
237{
238 machine_shutdown();
239 while (1);
240}
1da177e4
LT
241
242void machine_power_off(void)
243{
3d3f78d7 244 machine_shutdown();
1da177e4
LT
245 if (pm_power_off)
246 pm_power_off();
247}
248
be093beb 249void machine_restart(char *cmd)
1da177e4 250{
3d3f78d7 251 machine_shutdown();
ac15e00b 252
be093beb 253 arm_pm_restart(reboot_mode, cmd);
ac15e00b
RK
254
255 /* Give a grace period for failure to restart of 1s */
256 mdelay(1000);
257
258 /* Whoops - the platform was unable to reboot. Tell the user! */
259 printk("Reboot failed -- System halted\n");
260 while (1);
1da177e4
LT
261}
262
652a12ef 263void __show_regs(struct pt_regs *regs)
1da177e4 264{
154c772e
RK
265 unsigned long flags;
266 char buf[64];
1da177e4 267
154c772e 268 printk("CPU: %d %s (%s %.*s)\n",
22325525
RV
269 raw_smp_processor_id(), print_tainted(),
270 init_utsname()->release,
154c772e
RK
271 (int)strcspn(init_utsname()->version, " "),
272 init_utsname()->version);
1da177e4
LT
273 print_symbol("PC is at %s\n", instruction_pointer(regs));
274 print_symbol("LR is at %s\n", regs->ARM_lr);
154c772e 275 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
1da177e4 276 "sp : %08lx ip : %08lx fp : %08lx\n",
154c772e
RK
277 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
278 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
1da177e4
LT
279 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
280 regs->ARM_r10, regs->ARM_r9,
281 regs->ARM_r8);
282 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
283 regs->ARM_r7, regs->ARM_r6,
284 regs->ARM_r5, regs->ARM_r4);
285 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
286 regs->ARM_r3, regs->ARM_r2,
287 regs->ARM_r1, regs->ARM_r0);
154c772e
RK
288
289 flags = regs->ARM_cpsr;
290 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
291 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
292 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
293 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
294 buf[4] = '\0';
295
909d6c6c 296 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
154c772e 297 buf, interrupts_enabled(regs) ? "n" : "ff",
1da177e4
LT
298 fast_interrupts_enabled(regs) ? "n" : "ff",
299 processor_modes[processor_mode(regs)],
909d6c6c 300 isa_modes[isa_mode(regs)],
1da177e4 301 get_fs() == get_ds() ? "kernel" : "user");
154c772e 302#ifdef CONFIG_CPU_CP15
1da177e4 303 {
f12d0d7c 304 unsigned int ctrl;
154c772e
RK
305
306 buf[0] = '\0';
f12d0d7c 307#ifdef CONFIG_CPU_CP15_MMU
154c772e
RK
308 {
309 unsigned int transbase, dac;
310 asm("mrc p15, 0, %0, c2, c0\n\t"
311 "mrc p15, 0, %1, c3, c0\n"
312 : "=r" (transbase), "=r" (dac));
313 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
314 transbase, dac);
315 }
f12d0d7c 316#endif
154c772e
RK
317 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
318
319 printk("Control: %08x%s\n", ctrl, buf);
320 }
f12d0d7c 321#endif
1da177e4
LT
322}
323
652a12ef
RK
324void show_regs(struct pt_regs * regs)
325{
326 printk("\n");
19c5870c 327 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
652a12ef 328 __show_regs(regs);
b380ab4f 329 dump_stack();
652a12ef
RK
330}
331
797245f5
RK
332ATOMIC_NOTIFIER_HEAD(thread_notify_head);
333
334EXPORT_SYMBOL_GPL(thread_notify_head);
335
1da177e4
LT
336/*
337 * Free current thread data structures etc..
338 */
339void exit_thread(void)
340{
797245f5 341 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
1da177e4
LT
342}
343
1da177e4
LT
344void flush_thread(void)
345{
346 struct thread_info *thread = current_thread_info();
347 struct task_struct *tsk = current;
348
864232fa
WD
349 flush_ptrace_hw_breakpoint(tsk);
350
1da177e4
LT
351 memset(thread->used_cp, 0, sizeof(thread->used_cp));
352 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
d6551e88
RK
353 memset(&thread->fpstate, 0, sizeof(union fp_state));
354
355 thread_notify(THREAD_NOTIFY_FLUSH, thread);
1da177e4
LT
356}
357
358void release_thread(struct task_struct *dead_task)
359{
1da177e4
LT
360}
361
362asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
363
364int
6f2c55b8 365copy_thread(unsigned long clone_flags, unsigned long stack_start,
1da177e4
LT
366 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
367{
815d5ec8
AV
368 struct thread_info *thread = task_thread_info(p);
369 struct pt_regs *childregs = task_pt_regs(p);
1da177e4 370
1da177e4
LT
371 *childregs = *regs;
372 childregs->ARM_r0 = 0;
373 childregs->ARM_sp = stack_start;
374
375 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
376 thread->cpu_context.sp = (unsigned long)childregs;
377 thread->cpu_context.pc = (unsigned long)ret_from_fork;
378
864232fa
WD
379 clear_ptrace_hw_breakpoint(p);
380
1da177e4
LT
381 if (clone_flags & CLONE_SETTLS)
382 thread->tp_value = regs->ARM_r3;
383
2e82669a
CM
384 thread_notify(THREAD_NOTIFY_COPY, thread);
385
1da177e4
LT
386 return 0;
387}
388
cde3f860
AB
389/*
390 * Fill in the task's elfregs structure for a core dump.
391 */
392int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
393{
394 elf_core_copy_regs(elfregs, task_pt_regs(t));
395 return 1;
396}
397
1da177e4
LT
398/*
399 * fill in the fpe structure for a core dump...
400 */
401int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
402{
403 struct thread_info *thread = current_thread_info();
404 int used_math = thread->used_cp[1] | thread->used_cp[2];
405
406 if (used_math)
407 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
408
409 return used_math != 0;
410}
411EXPORT_SYMBOL(dump_fpu);
412
1da177e4
LT
413/*
414 * Shuffle the argument into the correct register before calling the
ac78884e
RK
415 * thread function. r4 is the thread argument, r5 is the pointer to
416 * the thread function, and r6 points to the exit function.
1da177e4
LT
417 */
418extern void kernel_thread_helper(void);
4260415f 419asm( ".pushsection .text\n"
1da177e4
LT
420" .align\n"
421" .type kernel_thread_helper, #function\n"
422"kernel_thread_helper:\n"
ac78884e
RK
423#ifdef CONFIG_TRACE_IRQFLAGS
424" bl trace_hardirqs_on\n"
425#endif
426" msr cpsr_c, r7\n"
427" mov r0, r4\n"
428" mov lr, r6\n"
429" mov pc, r5\n"
1da177e4 430" .size kernel_thread_helper, . - kernel_thread_helper\n"
4260415f 431" .popsection");
1da177e4 432
feb97c36
CM
433#ifdef CONFIG_ARM_UNWIND
434extern void kernel_thread_exit(long code);
4260415f 435asm( ".pushsection .text\n"
feb97c36
CM
436" .align\n"
437" .type kernel_thread_exit, #function\n"
438"kernel_thread_exit:\n"
439" .fnstart\n"
440" .cantunwind\n"
441" bl do_exit\n"
442" nop\n"
443" .fnend\n"
444" .size kernel_thread_exit, . - kernel_thread_exit\n"
4260415f 445" .popsection");
feb97c36
CM
446#else
447#define kernel_thread_exit do_exit
448#endif
449
1da177e4
LT
450/*
451 * Create a kernel thread.
452 */
453pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
454{
455 struct pt_regs regs;
456
457 memset(&regs, 0, sizeof(regs));
458
ac78884e
RK
459 regs.ARM_r4 = (unsigned long)arg;
460 regs.ARM_r5 = (unsigned long)fn;
461 regs.ARM_r6 = (unsigned long)kernel_thread_exit;
462 regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
1da177e4 463 regs.ARM_pc = (unsigned long)kernel_thread_helper;
ac78884e 464 regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;
1da177e4
LT
465
466 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
467}
468EXPORT_SYMBOL(kernel_thread);
469
470unsigned long get_wchan(struct task_struct *p)
471{
2d7c11bf 472 struct stackframe frame;
1da177e4
LT
473 int count = 0;
474 if (!p || p == current || p->state == TASK_RUNNING)
475 return 0;
476
2d7c11bf
CM
477 frame.fp = thread_saved_fp(p);
478 frame.sp = thread_saved_sp(p);
479 frame.lr = 0; /* recovered from the stack */
480 frame.pc = thread_saved_pc(p);
1da177e4 481 do {
2d7c11bf
CM
482 int ret = unwind_frame(&frame);
483 if (ret < 0)
1da177e4 484 return 0;
2d7c11bf
CM
485 if (!in_sched_functions(frame.pc))
486 return frame.pc;
1da177e4
LT
487 } while (count ++ < 16);
488 return 0;
489}
990cb8ac
NP
490
491unsigned long arch_randomize_brk(struct mm_struct *mm)
492{
493 unsigned long range_end = mm->brk + 0x02000000;
494 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
495}
ec706dab 496
6cde6d42 497#ifdef CONFIG_MMU
ec706dab
NP
498/*
499 * The vectors page is always readable from user space for the
500 * atomic helpers and the signal restart code. Let's declare a mapping
501 * for it so it is visible through ptrace and /proc/<pid>/mem.
502 */
503
504int vectors_user_mapping(void)
505{
506 struct mm_struct *mm = current->mm;
507 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
508 VM_READ | VM_EXEC |
509 VM_MAYREAD | VM_MAYEXEC |
510 VM_ALWAYSDUMP | VM_RESERVED,
511 NULL);
512}
513
514const char *arch_vma_name(struct vm_area_struct *vma)
515{
516 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
517}
6cde6d42 518#endif
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