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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 | ||
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 | ||
30 | #include <asm/system.h> | |
31 | #include <asm/io.h> | |
32 | #include <asm/leds.h> | |
33 | #include <asm/processor.h> | |
34 | #include <asm/uaccess.h> | |
35 | ||
36 | extern const char *processor_modes[]; | |
37 | extern void setup_mm_for_reboot(char mode); | |
38 | ||
39 | static volatile int hlt_counter; | |
40 | ||
41 | #include <asm/arch/system.h> | |
42 | ||
43 | void disable_hlt(void) | |
44 | { | |
45 | hlt_counter++; | |
46 | } | |
47 | ||
48 | EXPORT_SYMBOL(disable_hlt); | |
49 | ||
50 | void enable_hlt(void) | |
51 | { | |
52 | hlt_counter--; | |
53 | } | |
54 | ||
55 | EXPORT_SYMBOL(enable_hlt); | |
56 | ||
57 | static int __init nohlt_setup(char *__unused) | |
58 | { | |
59 | hlt_counter = 1; | |
60 | return 1; | |
61 | } | |
62 | ||
63 | static int __init hlt_setup(char *__unused) | |
64 | { | |
65 | hlt_counter = 0; | |
66 | return 1; | |
67 | } | |
68 | ||
69 | __setup("nohlt", nohlt_setup); | |
70 | __setup("hlt", hlt_setup); | |
71 | ||
72 | /* | |
73 | * The following aren't currently used. | |
74 | */ | |
75 | void (*pm_idle)(void); | |
76 | EXPORT_SYMBOL(pm_idle); | |
77 | ||
78 | void (*pm_power_off)(void); | |
79 | EXPORT_SYMBOL(pm_power_off); | |
80 | ||
81 | /* | |
82 | * This is our default idle handler. We need to disable | |
83 | * interrupts here to ensure we don't miss a wakeup call. | |
84 | */ | |
85 | void default_idle(void) | |
86 | { | |
87 | local_irq_disable(); | |
88 | if (!need_resched() && !hlt_counter) | |
89 | arch_idle(); | |
90 | local_irq_enable(); | |
91 | } | |
92 | ||
93 | /* | |
94 | * The idle thread. We try to conserve power, while trying to keep | |
95 | * overall latency low. The architecture specific idle is passed | |
96 | * a value to indicate the level of "idleness" of the system. | |
97 | */ | |
98 | void cpu_idle(void) | |
99 | { | |
100 | local_fiq_enable(); | |
101 | ||
102 | /* endless idle loop with no priority at all */ | |
103 | while (1) { | |
104 | void (*idle)(void) = pm_idle; | |
105 | if (!idle) | |
106 | idle = default_idle; | |
107 | preempt_disable(); | |
108 | leds_event(led_idle_start); | |
109 | while (!need_resched()) | |
110 | idle(); | |
111 | leds_event(led_idle_end); | |
112 | preempt_enable(); | |
113 | schedule(); | |
114 | } | |
115 | } | |
116 | ||
117 | static char reboot_mode = 'h'; | |
118 | ||
119 | int __init reboot_setup(char *str) | |
120 | { | |
121 | reboot_mode = str[0]; | |
122 | return 1; | |
123 | } | |
124 | ||
125 | __setup("reboot=", reboot_setup); | |
126 | ||
127 | void machine_halt(void) | |
128 | { | |
129 | } | |
130 | ||
131 | EXPORT_SYMBOL(machine_halt); | |
132 | ||
133 | void machine_power_off(void) | |
134 | { | |
135 | if (pm_power_off) | |
136 | pm_power_off(); | |
137 | } | |
138 | ||
139 | EXPORT_SYMBOL(machine_power_off); | |
140 | ||
141 | void machine_restart(char * __unused) | |
142 | { | |
143 | /* | |
144 | * Clean and disable cache, and turn off interrupts | |
145 | */ | |
146 | cpu_proc_fin(); | |
147 | ||
148 | /* | |
149 | * Tell the mm system that we are going to reboot - | |
150 | * we may need it to insert some 1:1 mappings so that | |
151 | * soft boot works. | |
152 | */ | |
153 | setup_mm_for_reboot(reboot_mode); | |
154 | ||
155 | /* | |
156 | * Now call the architecture specific reboot code. | |
157 | */ | |
158 | arch_reset(reboot_mode); | |
159 | ||
160 | /* | |
161 | * Whoops - the architecture was unable to reboot. | |
162 | * Tell the user! | |
163 | */ | |
164 | mdelay(1000); | |
165 | printk("Reboot failed -- System halted\n"); | |
166 | while (1); | |
167 | } | |
168 | ||
169 | EXPORT_SYMBOL(machine_restart); | |
170 | ||
171 | void show_regs(struct pt_regs * regs) | |
172 | { | |
173 | unsigned long flags; | |
174 | ||
175 | flags = condition_codes(regs); | |
176 | ||
177 | print_symbol("PC is at %s\n", instruction_pointer(regs)); | |
178 | print_symbol("LR is at %s\n", regs->ARM_lr); | |
179 | printk("pc : [<%08lx>] lr : [<%08lx>] %s\n" | |
180 | "sp : %08lx ip : %08lx fp : %08lx\n", | |
181 | instruction_pointer(regs), | |
182 | regs->ARM_lr, print_tainted(), regs->ARM_sp, | |
183 | regs->ARM_ip, regs->ARM_fp); | |
184 | printk("r10: %08lx r9 : %08lx r8 : %08lx\n", | |
185 | regs->ARM_r10, regs->ARM_r9, | |
186 | regs->ARM_r8); | |
187 | printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", | |
188 | regs->ARM_r7, regs->ARM_r6, | |
189 | regs->ARM_r5, regs->ARM_r4); | |
190 | printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", | |
191 | regs->ARM_r3, regs->ARM_r2, | |
192 | regs->ARM_r1, regs->ARM_r0); | |
193 | printk("Flags: %c%c%c%c", | |
194 | flags & PSR_N_BIT ? 'N' : 'n', | |
195 | flags & PSR_Z_BIT ? 'Z' : 'z', | |
196 | flags & PSR_C_BIT ? 'C' : 'c', | |
197 | flags & PSR_V_BIT ? 'V' : 'v'); | |
198 | printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n", | |
199 | interrupts_enabled(regs) ? "n" : "ff", | |
200 | fast_interrupts_enabled(regs) ? "n" : "ff", | |
201 | processor_modes[processor_mode(regs)], | |
202 | thumb_mode(regs) ? " (T)" : "", | |
203 | get_fs() == get_ds() ? "kernel" : "user"); | |
204 | { | |
205 | unsigned int ctrl, transbase, dac; | |
206 | __asm__ ( | |
207 | " mrc p15, 0, %0, c1, c0\n" | |
208 | " mrc p15, 0, %1, c2, c0\n" | |
209 | " mrc p15, 0, %2, c3, c0\n" | |
210 | : "=r" (ctrl), "=r" (transbase), "=r" (dac)); | |
211 | printk("Control: %04X Table: %08X DAC: %08X\n", | |
212 | ctrl, transbase, dac); | |
213 | } | |
214 | } | |
215 | ||
216 | void show_fpregs(struct user_fp *regs) | |
217 | { | |
218 | int i; | |
219 | ||
220 | for (i = 0; i < 8; i++) { | |
221 | unsigned long *p; | |
222 | char type; | |
223 | ||
224 | p = (unsigned long *)(regs->fpregs + i); | |
225 | ||
226 | switch (regs->ftype[i]) { | |
227 | case 1: type = 'f'; break; | |
228 | case 2: type = 'd'; break; | |
229 | case 3: type = 'e'; break; | |
230 | default: type = '?'; break; | |
231 | } | |
232 | if (regs->init_flag) | |
233 | type = '?'; | |
234 | ||
235 | printk(" f%d(%c): %08lx %08lx %08lx%c", | |
236 | i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); | |
237 | } | |
238 | ||
239 | ||
240 | printk("FPSR: %08lx FPCR: %08lx\n", | |
241 | (unsigned long)regs->fpsr, | |
242 | (unsigned long)regs->fpcr); | |
243 | } | |
244 | ||
245 | /* | |
246 | * Task structure and kernel stack allocation. | |
247 | */ | |
248 | static unsigned long *thread_info_head; | |
249 | static unsigned int nr_thread_info; | |
250 | ||
251 | #define EXTRA_TASK_STRUCT 4 | |
252 | #define ll_alloc_task_struct() ((struct thread_info *) __get_free_pages(GFP_KERNEL,1)) | |
253 | #define ll_free_task_struct(p) free_pages((unsigned long)(p),1) | |
254 | ||
255 | struct thread_info *alloc_thread_info(struct task_struct *task) | |
256 | { | |
257 | struct thread_info *thread = NULL; | |
258 | ||
259 | if (EXTRA_TASK_STRUCT) { | |
260 | unsigned long *p = thread_info_head; | |
261 | ||
262 | if (p) { | |
263 | thread_info_head = (unsigned long *)p[0]; | |
264 | nr_thread_info -= 1; | |
265 | } | |
266 | thread = (struct thread_info *)p; | |
267 | } | |
268 | ||
269 | if (!thread) | |
270 | thread = ll_alloc_task_struct(); | |
271 | ||
272 | #ifdef CONFIG_MAGIC_SYSRQ | |
273 | /* | |
274 | * The stack must be cleared if you want SYSRQ-T to | |
275 | * give sensible stack usage information | |
276 | */ | |
277 | if (thread) { | |
278 | char *p = (char *)thread; | |
279 | memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE); | |
280 | } | |
281 | #endif | |
282 | return thread; | |
283 | } | |
284 | ||
285 | void free_thread_info(struct thread_info *thread) | |
286 | { | |
287 | if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) { | |
288 | unsigned long *p = (unsigned long *)thread; | |
289 | p[0] = (unsigned long)thread_info_head; | |
290 | thread_info_head = p; | |
291 | nr_thread_info += 1; | |
292 | } else | |
293 | ll_free_task_struct(thread); | |
294 | } | |
295 | ||
296 | /* | |
297 | * Free current thread data structures etc.. | |
298 | */ | |
299 | void exit_thread(void) | |
300 | { | |
301 | } | |
302 | ||
303 | static void default_fp_init(union fp_state *fp) | |
304 | { | |
305 | memset(fp, 0, sizeof(union fp_state)); | |
306 | } | |
307 | ||
308 | void (*fp_init)(union fp_state *) = default_fp_init; | |
309 | EXPORT_SYMBOL(fp_init); | |
310 | ||
311 | void flush_thread(void) | |
312 | { | |
313 | struct thread_info *thread = current_thread_info(); | |
314 | struct task_struct *tsk = current; | |
315 | ||
316 | memset(thread->used_cp, 0, sizeof(thread->used_cp)); | |
317 | memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); | |
318 | #if defined(CONFIG_IWMMXT) | |
319 | iwmmxt_task_release(thread); | |
320 | #endif | |
321 | fp_init(&thread->fpstate); | |
322 | #if defined(CONFIG_VFP) | |
323 | vfp_flush_thread(&thread->vfpstate); | |
324 | #endif | |
325 | } | |
326 | ||
327 | void release_thread(struct task_struct *dead_task) | |
328 | { | |
329 | #if defined(CONFIG_VFP) | |
330 | vfp_release_thread(&dead_task->thread_info->vfpstate); | |
331 | #endif | |
332 | #if defined(CONFIG_IWMMXT) | |
333 | iwmmxt_task_release(dead_task->thread_info); | |
334 | #endif | |
335 | } | |
336 | ||
337 | asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); | |
338 | ||
339 | int | |
340 | copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, | |
341 | unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) | |
342 | { | |
343 | struct thread_info *thread = p->thread_info; | |
344 | struct pt_regs *childregs; | |
345 | ||
346 | childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_SIZE - 8)) - 1; | |
347 | *childregs = *regs; | |
348 | childregs->ARM_r0 = 0; | |
349 | childregs->ARM_sp = stack_start; | |
350 | ||
351 | memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); | |
352 | thread->cpu_context.sp = (unsigned long)childregs; | |
353 | thread->cpu_context.pc = (unsigned long)ret_from_fork; | |
354 | ||
355 | if (clone_flags & CLONE_SETTLS) | |
356 | thread->tp_value = regs->ARM_r3; | |
357 | ||
358 | return 0; | |
359 | } | |
360 | ||
361 | /* | |
362 | * fill in the fpe structure for a core dump... | |
363 | */ | |
364 | int dump_fpu (struct pt_regs *regs, struct user_fp *fp) | |
365 | { | |
366 | struct thread_info *thread = current_thread_info(); | |
367 | int used_math = thread->used_cp[1] | thread->used_cp[2]; | |
368 | ||
369 | if (used_math) | |
370 | memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); | |
371 | ||
372 | return used_math != 0; | |
373 | } | |
374 | EXPORT_SYMBOL(dump_fpu); | |
375 | ||
376 | /* | |
377 | * fill in the user structure for a core dump.. | |
378 | */ | |
379 | void dump_thread(struct pt_regs * regs, struct user * dump) | |
380 | { | |
381 | struct task_struct *tsk = current; | |
382 | ||
383 | dump->magic = CMAGIC; | |
384 | dump->start_code = tsk->mm->start_code; | |
385 | dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); | |
386 | ||
387 | dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; | |
388 | dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
389 | dump->u_ssize = 0; | |
390 | ||
391 | dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; | |
392 | dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; | |
393 | dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; | |
394 | dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; | |
395 | dump->u_debugreg[4] = tsk->thread.debug.nsaved; | |
396 | ||
397 | if (dump->start_stack < 0x04000000) | |
398 | dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; | |
399 | ||
400 | dump->regs = *regs; | |
401 | dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); | |
402 | } | |
403 | EXPORT_SYMBOL(dump_thread); | |
404 | ||
405 | /* | |
406 | * Shuffle the argument into the correct register before calling the | |
407 | * thread function. r1 is the thread argument, r2 is the pointer to | |
408 | * the thread function, and r3 points to the exit function. | |
409 | */ | |
410 | extern void kernel_thread_helper(void); | |
411 | asm( ".section .text\n" | |
412 | " .align\n" | |
413 | " .type kernel_thread_helper, #function\n" | |
414 | "kernel_thread_helper:\n" | |
415 | " mov r0, r1\n" | |
416 | " mov lr, r3\n" | |
417 | " mov pc, r2\n" | |
418 | " .size kernel_thread_helper, . - kernel_thread_helper\n" | |
419 | " .previous"); | |
420 | ||
421 | /* | |
422 | * Create a kernel thread. | |
423 | */ | |
424 | pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) | |
425 | { | |
426 | struct pt_regs regs; | |
427 | ||
428 | memset(®s, 0, sizeof(regs)); | |
429 | ||
430 | regs.ARM_r1 = (unsigned long)arg; | |
431 | regs.ARM_r2 = (unsigned long)fn; | |
432 | regs.ARM_r3 = (unsigned long)do_exit; | |
433 | regs.ARM_pc = (unsigned long)kernel_thread_helper; | |
434 | regs.ARM_cpsr = SVC_MODE; | |
435 | ||
436 | return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); | |
437 | } | |
438 | EXPORT_SYMBOL(kernel_thread); | |
439 | ||
440 | unsigned long get_wchan(struct task_struct *p) | |
441 | { | |
442 | unsigned long fp, lr; | |
443 | unsigned long stack_page; | |
444 | int count = 0; | |
445 | if (!p || p == current || p->state == TASK_RUNNING) | |
446 | return 0; | |
447 | ||
448 | stack_page = 4096 + (unsigned long)p->thread_info; | |
449 | fp = thread_saved_fp(p); | |
450 | do { | |
451 | if (fp < stack_page || fp > 4092+stack_page) | |
452 | return 0; | |
453 | lr = pc_pointer (((unsigned long *)fp)[-1]); | |
454 | if (!in_sched_functions(lr)) | |
455 | return lr; | |
456 | fp = *(unsigned long *) (fp - 12); | |
457 | } while (count ++ < 16); | |
458 | return 0; | |
459 | } | |
460 | EXPORT_SYMBOL(get_wchan); |