diff options
Diffstat (limited to 'arch/arm/kernel/process.c')
| -rw-r--r-- | arch/arm/kernel/process.c | 112 |
1 files changed, 67 insertions, 45 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index d3ea6fa89521..39196dff478c 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -34,6 +34,7 @@ #include <asm/processor.h> #include <asm/system.h> #include <asm/thread_notify.h> +#include <asm/stacktrace.h> #include <asm/mach/time.h> static const char *processor_modes[] = { @@ -82,7 +83,7 @@ static int __init hlt_setup(char *__unused) __setup("nohlt", nohlt_setup); __setup("hlt", hlt_setup); -void arm_machine_restart(char mode) +void arm_machine_restart(char mode, const char *cmd) { /* * Clean and disable cache, and turn off interrupts @@ -99,7 +100,7 @@ void arm_machine_restart(char mode) /* * Now call the architecture specific reboot code. */ - arch_reset(mode); + arch_reset(mode, cmd); /* * Whoops - the architecture was unable to reboot. @@ -113,13 +114,10 @@ void arm_machine_restart(char mode) /* * Function pointers to optional machine specific functions */ -void (*pm_idle)(void); -EXPORT_SYMBOL(pm_idle); - void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); -void (*arm_pm_restart)(char str) = arm_machine_restart; +void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart; EXPORT_SYMBOL_GPL(arm_pm_restart); @@ -129,20 +127,19 @@ EXPORT_SYMBOL_GPL(arm_pm_restart); */ static void default_idle(void) { - if (hlt_counter) - cpu_relax(); - else { - local_irq_disable(); - if (!need_resched()) - arch_idle(); - local_irq_enable(); - } + if (!need_resched()) + arch_idle(); + local_irq_enable(); } +void (*pm_idle)(void) = default_idle; +EXPORT_SYMBOL(pm_idle); + /* - * The idle thread. We try to conserve power, while trying to keep - * overall latency low. The architecture specific idle is passed - * a value to indicate the level of "idleness" of the system. + * The idle thread, has rather strange semantics for calling pm_idle, + * but this is what x86 does and we need to do the same, so that + * things like cpuidle get called in the same way. The only difference + * is that we always respect 'hlt_counter' to prevent low power idle. */ void cpu_idle(void) { @@ -150,21 +147,31 @@ void cpu_idle(void) /* endless idle loop with no priority at all */ while (1) { - void (*idle)(void) = pm_idle; - + tick_nohz_stop_sched_tick(1); + leds_event(led_idle_start); + while (!need_resched()) { #ifdef CONFIG_HOTPLUG_CPU - if (cpu_is_offline(smp_processor_id())) { - leds_event(led_idle_start); - cpu_die(); - } + if (cpu_is_offline(smp_processor_id())) + cpu_die(); #endif - if (!idle) - idle = default_idle; - leds_event(led_idle_start); - tick_nohz_stop_sched_tick(1); - while (!need_resched()) - idle(); + local_irq_disable(); + if (hlt_counter) { + local_irq_enable(); + cpu_relax(); + } else { + stop_critical_timings(); + pm_idle(); + start_critical_timings(); + /* + * This will eventually be removed - pm_idle + * functions should always return with IRQs + * enabled. + */ + WARN_ON(irqs_disabled()); + local_irq_enable(); + } + } leds_event(led_idle_end); tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); @@ -194,9 +201,9 @@ void machine_power_off(void) pm_power_off(); } -void machine_restart(char * __unused) +void machine_restart(char *cmd) { - arm_pm_restart(reboot_mode); + arm_pm_restart(reboot_mode, cmd); } void __show_regs(struct pt_regs *regs) @@ -300,7 +307,7 @@ void release_thread(struct task_struct *dead_task) asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); int -copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, +copy_thread(unsigned long clone_flags, unsigned long stack_start, unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) { struct thread_info *thread = task_thread_info(p); @@ -351,6 +358,23 @@ asm( ".section .text\n" " .size kernel_thread_helper, . - kernel_thread_helper\n" " .previous"); +#ifdef CONFIG_ARM_UNWIND +extern void kernel_thread_exit(long code); +asm( ".section .text\n" +" .align\n" +" .type kernel_thread_exit, #function\n" +"kernel_thread_exit:\n" +" .fnstart\n" +" .cantunwind\n" +" bl do_exit\n" +" nop\n" +" .fnend\n" +" .size kernel_thread_exit, . - kernel_thread_exit\n" +" .previous"); +#else +#define kernel_thread_exit do_exit +#endif + /* * Create a kernel thread. */ @@ -362,9 +386,9 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) regs.ARM_r1 = (unsigned long)arg; regs.ARM_r2 = (unsigned long)fn; - regs.ARM_r3 = (unsigned long)do_exit; + regs.ARM_r3 = (unsigned long)kernel_thread_exit; regs.ARM_pc = (unsigned long)kernel_thread_helper; - regs.ARM_cpsr = SVC_MODE; + regs.ARM_cpsr = SVC_MODE | PSR_ENDSTATE; return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } @@ -372,23 +396,21 @@ EXPORT_SYMBOL(kernel_thread); unsigned long get_wchan(struct task_struct *p) { - unsigned long fp, lr; - unsigned long stack_start, stack_end; + struct stackframe frame; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; - stack_start = (unsigned long)end_of_stack(p); - stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE; - - fp = thread_saved_fp(p); + frame.fp = thread_saved_fp(p); + frame.sp = thread_saved_sp(p); + frame.lr = 0; /* recovered from the stack */ + frame.pc = thread_saved_pc(p); do { - if (fp < stack_start || fp > stack_end) + int ret = unwind_frame(&frame); + if (ret < 0) return 0; - lr = ((unsigned long *)fp)[-1]; - if (!in_sched_functions(lr)) - return lr; - fp = *(unsigned long *) (fp - 12); + if (!in_sched_functions(frame.pc)) + return frame.pc; } while (count ++ < 16); return 0; } |