dbd8ca89b385b24f00b0d252ddab677db034c8ef
[sfrench/cifs-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/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(&regs, 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, &regs, 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);