2 * linux/arch/arm/kernel/process.c
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
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.
13 #include <linux/config.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.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>
30 #include <asm/system.h>
33 #include <asm/processor.h>
34 #include <asm/uaccess.h>
36 extern const char *processor_modes[];
37 extern void setup_mm_for_reboot(char mode);
39 static volatile int hlt_counter;
41 #include <asm/arch/system.h>
43 void disable_hlt(void)
48 EXPORT_SYMBOL(disable_hlt);
55 EXPORT_SYMBOL(enable_hlt);
57 static int __init nohlt_setup(char *__unused)
63 static int __init hlt_setup(char *__unused)
69 __setup("nohlt", nohlt_setup);
70 __setup("hlt", hlt_setup);
73 * The following aren't currently used.
75 void (*pm_idle)(void);
76 EXPORT_SYMBOL(pm_idle);
78 void (*pm_power_off)(void);
79 EXPORT_SYMBOL(pm_power_off);
82 * This is our default idle handler. We need to disable
83 * interrupts here to ensure we don't miss a wakeup call.
85 void default_idle(void)
88 if (!need_resched() && !hlt_counter)
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.
100 /* endless idle loop with no priority at all */
102 void (*idle)(void) = pm_idle;
106 leds_event(led_idle_start);
107 while (!need_resched())
109 leds_event(led_idle_end);
115 static char reboot_mode = 'h';
117 int __init reboot_setup(char *str)
119 reboot_mode = str[0];
123 __setup("reboot=", reboot_setup);
125 void machine_halt(void)
129 EXPORT_SYMBOL(machine_halt);
131 void machine_power_off(void)
137 EXPORT_SYMBOL(machine_power_off);
139 void machine_restart(char * __unused)
142 * Clean and disable cache, and turn off interrupts
147 * Tell the mm system that we are going to reboot -
148 * we may need it to insert some 1:1 mappings so that
151 setup_mm_for_reboot(reboot_mode);
154 * Now call the architecture specific reboot code.
156 arch_reset(reboot_mode);
159 * Whoops - the architecture was unable to reboot.
163 printk("Reboot failed -- System halted\n");
167 EXPORT_SYMBOL(machine_restart);
169 void show_regs(struct pt_regs * regs)
173 flags = condition_codes(regs);
175 print_symbol("PC is at %s\n", instruction_pointer(regs));
176 print_symbol("LR is at %s\n", regs->ARM_lr);
177 printk("pc : [<%08lx>] lr : [<%08lx>] %s\n"
178 "sp : %08lx ip : %08lx fp : %08lx\n",
179 instruction_pointer(regs),
180 regs->ARM_lr, print_tainted(), regs->ARM_sp,
181 regs->ARM_ip, regs->ARM_fp);
182 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
183 regs->ARM_r10, regs->ARM_r9,
185 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
186 regs->ARM_r7, regs->ARM_r6,
187 regs->ARM_r5, regs->ARM_r4);
188 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
189 regs->ARM_r3, regs->ARM_r2,
190 regs->ARM_r1, regs->ARM_r0);
191 printk("Flags: %c%c%c%c",
192 flags & PSR_N_BIT ? 'N' : 'n',
193 flags & PSR_Z_BIT ? 'Z' : 'z',
194 flags & PSR_C_BIT ? 'C' : 'c',
195 flags & PSR_V_BIT ? 'V' : 'v');
196 printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n",
197 interrupts_enabled(regs) ? "n" : "ff",
198 fast_interrupts_enabled(regs) ? "n" : "ff",
199 processor_modes[processor_mode(regs)],
200 thumb_mode(regs) ? " (T)" : "",
201 get_fs() == get_ds() ? "kernel" : "user");
203 unsigned int ctrl, transbase, dac;
205 " mrc p15, 0, %0, c1, c0\n"
206 " mrc p15, 0, %1, c2, c0\n"
207 " mrc p15, 0, %2, c3, c0\n"
208 : "=r" (ctrl), "=r" (transbase), "=r" (dac));
209 printk("Control: %04X Table: %08X DAC: %08X\n",
210 ctrl, transbase, dac);
214 void show_fpregs(struct user_fp *regs)
218 for (i = 0; i < 8; i++) {
222 p = (unsigned long *)(regs->fpregs + i);
224 switch (regs->ftype[i]) {
225 case 1: type = 'f'; break;
226 case 2: type = 'd'; break;
227 case 3: type = 'e'; break;
228 default: type = '?'; break;
233 printk(" f%d(%c): %08lx %08lx %08lx%c",
234 i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' ');
238 printk("FPSR: %08lx FPCR: %08lx\n",
239 (unsigned long)regs->fpsr,
240 (unsigned long)regs->fpcr);
244 * Task structure and kernel stack allocation.
246 static unsigned long *thread_info_head;
247 static unsigned int nr_thread_info;
249 #define EXTRA_TASK_STRUCT 4
250 #define ll_alloc_task_struct() ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
251 #define ll_free_task_struct(p) free_pages((unsigned long)(p),1)
253 struct thread_info *alloc_thread_info(struct task_struct *task)
255 struct thread_info *thread = NULL;
257 if (EXTRA_TASK_STRUCT) {
258 unsigned long *p = thread_info_head;
261 thread_info_head = (unsigned long *)p[0];
264 thread = (struct thread_info *)p;
268 thread = ll_alloc_task_struct();
270 #ifdef CONFIG_MAGIC_SYSRQ
272 * The stack must be cleared if you want SYSRQ-T to
273 * give sensible stack usage information
276 char *p = (char *)thread;
277 memzero(p+KERNEL_STACK_SIZE, KERNEL_STACK_SIZE);
283 void free_thread_info(struct thread_info *thread)
285 if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) {
286 unsigned long *p = (unsigned long *)thread;
287 p[0] = (unsigned long)thread_info_head;
288 thread_info_head = p;
291 ll_free_task_struct(thread);
295 * Free current thread data structures etc..
297 void exit_thread(void)
301 static void default_fp_init(union fp_state *fp)
303 memset(fp, 0, sizeof(union fp_state));
306 void (*fp_init)(union fp_state *) = default_fp_init;
307 EXPORT_SYMBOL(fp_init);
309 void flush_thread(void)
311 struct thread_info *thread = current_thread_info();
312 struct task_struct *tsk = current;
314 memset(thread->used_cp, 0, sizeof(thread->used_cp));
315 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
316 #if defined(CONFIG_IWMMXT)
317 iwmmxt_task_release(thread);
319 fp_init(&thread->fpstate);
320 #if defined(CONFIG_VFP)
321 vfp_flush_thread(&thread->vfpstate);
325 void release_thread(struct task_struct *dead_task)
327 #if defined(CONFIG_VFP)
328 vfp_release_thread(&dead_task->thread_info->vfpstate);
330 #if defined(CONFIG_IWMMXT)
331 iwmmxt_task_release(dead_task->thread_info);
335 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
338 copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
339 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
341 struct thread_info *thread = p->thread_info;
342 struct pt_regs *childregs;
344 childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_SIZE - 8)) - 1;
346 childregs->ARM_r0 = 0;
347 childregs->ARM_sp = stack_start;
349 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
350 thread->cpu_context.sp = (unsigned long)childregs;
351 thread->cpu_context.pc = (unsigned long)ret_from_fork;
357 * fill in the fpe structure for a core dump...
359 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
361 struct thread_info *thread = current_thread_info();
362 int used_math = thread->used_cp[1] | thread->used_cp[2];
365 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
367 return used_math != 0;
369 EXPORT_SYMBOL(dump_fpu);
372 * fill in the user structure for a core dump..
374 void dump_thread(struct pt_regs * regs, struct user * dump)
376 struct task_struct *tsk = current;
378 dump->magic = CMAGIC;
379 dump->start_code = tsk->mm->start_code;
380 dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1);
382 dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT;
383 dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT;
386 dump->u_debugreg[0] = tsk->thread.debug.bp[0].address;
387 dump->u_debugreg[1] = tsk->thread.debug.bp[1].address;
388 dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm;
389 dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm;
390 dump->u_debugreg[4] = tsk->thread.debug.nsaved;
392 if (dump->start_stack < 0x04000000)
393 dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT;
396 dump->u_fpvalid = dump_fpu (regs, &dump->u_fp);
398 EXPORT_SYMBOL(dump_thread);
401 * Shuffle the argument into the correct register before calling the
402 * thread function. r1 is the thread argument, r2 is the pointer to
403 * the thread function, and r3 points to the exit function.
405 extern void kernel_thread_helper(void);
406 asm( ".section .text\n"
408 " .type kernel_thread_helper, #function\n"
409 "kernel_thread_helper:\n"
413 " .size kernel_thread_helper, . - kernel_thread_helper\n"
417 * Create a kernel thread.
419 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
423 memset(®s, 0, sizeof(regs));
425 regs.ARM_r1 = (unsigned long)arg;
426 regs.ARM_r2 = (unsigned long)fn;
427 regs.ARM_r3 = (unsigned long)do_exit;
428 regs.ARM_pc = (unsigned long)kernel_thread_helper;
429 regs.ARM_cpsr = SVC_MODE;
431 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
433 EXPORT_SYMBOL(kernel_thread);
435 unsigned long get_wchan(struct task_struct *p)
437 unsigned long fp, lr;
438 unsigned long stack_page;
440 if (!p || p == current || p->state == TASK_RUNNING)
443 stack_page = 4096 + (unsigned long)p->thread_info;
444 fp = thread_saved_fp(p);
446 if (fp < stack_page || fp > 4092+stack_page)
448 lr = pc_pointer (((unsigned long *)fp)[-1]);
449 if (!in_sched_functions(lr))
451 fp = *(unsigned long *) (fp - 12);
452 } while (count ++ < 16);
455 EXPORT_SYMBOL(get_wchan);