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