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/module.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/user.h>
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>
25 #include <linux/cpu.h>
26 #include <linux/elfcore.h>
28 #include <linux/tick.h>
29 #include <linux/utsname.h>
30 #include <linux/uaccess.h>
31 #include <linux/random.h>
32 #include <linux/hw_breakpoint.h>
34 #include <asm/cacheflush.h>
36 #include <asm/processor.h>
37 #include <asm/system.h>
38 #include <asm/thread_notify.h>
39 #include <asm/stacktrace.h>
40 #include <asm/mach/time.h>
42 #ifdef CONFIG_CC_STACKPROTECTOR
43 #include <linux/stackprotector.h>
44 unsigned long __stack_chk_guard __read_mostly;
45 EXPORT_SYMBOL(__stack_chk_guard);
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"
55 static const char *isa_modes[] = {
56 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
59 extern void setup_mm_for_reboot(char mode);
61 static volatile int hlt_counter;
63 #include <mach/system.h>
65 void disable_hlt(void)
70 EXPORT_SYMBOL(disable_hlt);
77 EXPORT_SYMBOL(enable_hlt);
79 static int __init nohlt_setup(char *__unused)
85 static int __init hlt_setup(char *__unused)
91 __setup("nohlt", nohlt_setup);
92 __setup("hlt", hlt_setup);
94 void arm_machine_restart(char mode, const char *cmd)
96 /* Disable interrupts first */
101 * Tell the mm system that we are going to reboot -
102 * we may need it to insert some 1:1 mappings so that
105 setup_mm_for_reboot(mode);
107 /* Clean and invalidate caches */
110 /* Turn off caching */
113 /* Push out any further dirty data, and ensure cache is empty */
117 * Now call the architecture specific reboot code.
119 arch_reset(mode, cmd);
122 * Whoops - the architecture was unable to reboot.
126 printk("Reboot failed -- System halted\n");
131 * Function pointers to optional machine specific functions
133 void (*pm_power_off)(void);
134 EXPORT_SYMBOL(pm_power_off);
136 void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
137 EXPORT_SYMBOL_GPL(arm_pm_restart);
139 static void do_nothing(void *unused)
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.
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.
151 void cpu_idle_wait(void)
154 /* kick all the CPUs so that they exit out of pm_idle */
155 smp_call_function(do_nothing, NULL, 1);
157 EXPORT_SYMBOL_GPL(cpu_idle_wait);
160 * This is our default idle handler. We need to disable
161 * interrupts here to ensure we don't miss a wakeup call.
163 static void default_idle(void)
170 void (*pm_idle)(void) = default_idle;
171 EXPORT_SYMBOL(pm_idle);
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.
183 /* endless idle loop with no priority at all */
185 tick_nohz_stop_sched_tick(1);
186 leds_event(led_idle_start);
187 while (!need_resched()) {
188 #ifdef CONFIG_HOTPLUG_CPU
189 if (cpu_is_offline(smp_processor_id()))
198 stop_critical_timings();
200 start_critical_timings();
202 * This will eventually be removed - pm_idle
203 * functions should always return with IRQs
206 WARN_ON(irqs_disabled());
210 leds_event(led_idle_end);
211 tick_nohz_restart_sched_tick();
212 preempt_enable_no_resched();
218 static char reboot_mode = 'h';
220 int __init reboot_setup(char *str)
222 reboot_mode = str[0];
226 __setup("reboot=", reboot_setup);
228 void machine_shutdown(void)
235 void machine_halt(void)
241 void machine_power_off(void)
248 void machine_restart(char *cmd)
251 arm_pm_restart(reboot_mode, cmd);
254 void __show_regs(struct pt_regs *regs)
259 printk("CPU: %d %s (%s %.*s)\n",
260 raw_smp_processor_id(), print_tainted(),
261 init_utsname()->release,
262 (int)strcspn(init_utsname()->version, " "),
263 init_utsname()->version);
264 print_symbol("PC is at %s\n", instruction_pointer(regs));
265 print_symbol("LR is at %s\n", regs->ARM_lr);
266 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
267 "sp : %08lx ip : %08lx fp : %08lx\n",
268 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
269 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
270 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
271 regs->ARM_r10, regs->ARM_r9,
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);
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';
287 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
288 buf, interrupts_enabled(regs) ? "n" : "ff",
289 fast_interrupts_enabled(regs) ? "n" : "ff",
290 processor_modes[processor_mode(regs)],
291 isa_modes[isa_mode(regs)],
292 get_fs() == get_ds() ? "kernel" : "user");
293 #ifdef CONFIG_CPU_CP15
298 #ifdef CONFIG_CPU_CP15_MMU
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",
308 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
310 printk("Control: %08x%s\n", ctrl, buf);
315 void show_regs(struct pt_regs * regs)
318 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
323 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
325 EXPORT_SYMBOL_GPL(thread_notify_head);
328 * Free current thread data structures etc..
330 void exit_thread(void)
332 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
335 void flush_thread(void)
337 struct thread_info *thread = current_thread_info();
338 struct task_struct *tsk = current;
340 flush_ptrace_hw_breakpoint(tsk);
342 memset(thread->used_cp, 0, sizeof(thread->used_cp));
343 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
344 memset(&thread->fpstate, 0, sizeof(union fp_state));
346 thread_notify(THREAD_NOTIFY_FLUSH, thread);
349 void release_thread(struct task_struct *dead_task)
353 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
356 copy_thread(unsigned long clone_flags, unsigned long stack_start,
357 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
359 struct thread_info *thread = task_thread_info(p);
360 struct pt_regs *childregs = task_pt_regs(p);
363 childregs->ARM_r0 = 0;
364 childregs->ARM_sp = stack_start;
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;
370 clear_ptrace_hw_breakpoint(p);
372 if (clone_flags & CLONE_SETTLS)
373 thread->tp_value = regs->ARM_r3;
375 thread_notify(THREAD_NOTIFY_COPY, thread);
381 * Fill in the task's elfregs structure for a core dump.
383 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
385 elf_core_copy_regs(elfregs, task_pt_regs(t));
390 * fill in the fpe structure for a core dump...
392 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
394 struct thread_info *thread = current_thread_info();
395 int used_math = thread->used_cp[1] | thread->used_cp[2];
398 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
400 return used_math != 0;
402 EXPORT_SYMBOL(dump_fpu);
405 * Shuffle the argument into the correct register before calling the
406 * thread function. r4 is the thread argument, r5 is the pointer to
407 * the thread function, and r6 points to the exit function.
409 extern void kernel_thread_helper(void);
410 asm( ".pushsection .text\n"
412 " .type kernel_thread_helper, #function\n"
413 "kernel_thread_helper:\n"
414 #ifdef CONFIG_TRACE_IRQFLAGS
415 " bl trace_hardirqs_on\n"
421 " .size kernel_thread_helper, . - kernel_thread_helper\n"
424 #ifdef CONFIG_ARM_UNWIND
425 extern void kernel_thread_exit(long code);
426 asm( ".pushsection .text\n"
428 " .type kernel_thread_exit, #function\n"
429 "kernel_thread_exit:\n"
435 " .size kernel_thread_exit, . - kernel_thread_exit\n"
438 #define kernel_thread_exit do_exit
442 * Create a kernel thread.
444 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
448 memset(®s, 0, sizeof(regs));
450 regs.ARM_r4 = (unsigned long)arg;
451 regs.ARM_r5 = (unsigned long)fn;
452 regs.ARM_r6 = (unsigned long)kernel_thread_exit;
453 regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
454 regs.ARM_pc = (unsigned long)kernel_thread_helper;
455 regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;
457 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
459 EXPORT_SYMBOL(kernel_thread);
461 unsigned long get_wchan(struct task_struct *p)
463 struct stackframe frame;
465 if (!p || p == current || p->state == TASK_RUNNING)
468 frame.fp = thread_saved_fp(p);
469 frame.sp = thread_saved_sp(p);
470 frame.lr = 0; /* recovered from the stack */
471 frame.pc = thread_saved_pc(p);
473 int ret = unwind_frame(&frame);
476 if (!in_sched_functions(frame.pc))
478 } while (count ++ < 16);
482 unsigned long arch_randomize_brk(struct mm_struct *mm)
484 unsigned long range_end = mm->brk + 0x02000000;
485 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
490 * The vectors page is always readable from user space for the
491 * atomic helpers and the signal restart code. Let's declare a mapping
492 * for it so it is visible through ptrace and /proc/<pid>/mem.
495 int vectors_user_mapping(void)
497 struct mm_struct *mm = current->mm;
498 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
500 VM_MAYREAD | VM_MAYEXEC |
501 VM_ALWAYSDUMP | VM_RESERVED,
505 const char *arch_vma_name(struct vm_area_struct *vma)
507 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;