diff options
Diffstat (limited to 'arch/x86_64/kernel/process.c')
| -rw-r--r-- | arch/x86_64/kernel/process.c | 82 |
1 files changed, 54 insertions, 28 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c index 3060ed97b755..8ded407e4a94 100644 --- a/arch/x86_64/kernel/process.c +++ b/arch/x86_64/kernel/process.c @@ -36,6 +36,7 @@ #include <linux/utsname.h> #include <linux/random.h> #include <linux/kprobes.h> +#include <linux/notifier.h> #include <asm/uaccess.h> #include <asm/pgtable.h> @@ -50,13 +51,12 @@ #include <asm/desc.h> #include <asm/proto.h> #include <asm/ia32.h> +#include <asm/idle.h> asmlinkage extern void ret_from_fork(void); unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED; -static atomic_t hlt_counter = ATOMIC_INIT(0); - unsigned long boot_option_idle_override = 0; EXPORT_SYMBOL(boot_option_idle_override); @@ -66,19 +66,49 @@ EXPORT_SYMBOL(boot_option_idle_override); void (*pm_idle)(void); static DEFINE_PER_CPU(unsigned int, cpu_idle_state); -void disable_hlt(void) +static struct notifier_block *idle_notifier; +static DEFINE_SPINLOCK(idle_notifier_lock); + +void idle_notifier_register(struct notifier_block *n) +{ + unsigned long flags; + spin_lock_irqsave(&idle_notifier_lock, flags); + notifier_chain_register(&idle_notifier, n); + spin_unlock_irqrestore(&idle_notifier_lock, flags); +} +EXPORT_SYMBOL_GPL(idle_notifier_register); + +void idle_notifier_unregister(struct notifier_block *n) { - atomic_inc(&hlt_counter); + unsigned long flags; + spin_lock_irqsave(&idle_notifier_lock, flags); + notifier_chain_unregister(&idle_notifier, n); + spin_unlock_irqrestore(&idle_notifier_lock, flags); } +EXPORT_SYMBOL(idle_notifier_unregister); -EXPORT_SYMBOL(disable_hlt); +enum idle_state { CPU_IDLE, CPU_NOT_IDLE }; +static DEFINE_PER_CPU(enum idle_state, idle_state) = CPU_NOT_IDLE; -void enable_hlt(void) +void enter_idle(void) { - atomic_dec(&hlt_counter); + __get_cpu_var(idle_state) = CPU_IDLE; + notifier_call_chain(&idle_notifier, IDLE_START, NULL); } -EXPORT_SYMBOL(enable_hlt); +static void __exit_idle(void) +{ + __get_cpu_var(idle_state) = CPU_NOT_IDLE; + notifier_call_chain(&idle_notifier, IDLE_END, NULL); +} + +/* Called from interrupts to signify idle end */ +void exit_idle(void) +{ + if (current->pid | read_pda(irqcount)) + return; + __exit_idle(); +} /* * We use this if we don't have any better @@ -88,21 +118,16 @@ void default_idle(void) { local_irq_enable(); - if (!atomic_read(&hlt_counter)) { - clear_thread_flag(TIF_POLLING_NRFLAG); - smp_mb__after_clear_bit(); - while (!need_resched()) { - local_irq_disable(); - if (!need_resched()) - safe_halt(); - else - local_irq_enable(); - } - set_thread_flag(TIF_POLLING_NRFLAG); - } else { - while (!need_resched()) - cpu_relax(); + clear_thread_flag(TIF_POLLING_NRFLAG); + smp_mb__after_clear_bit(); + while (!need_resched()) { + local_irq_disable(); + if (!need_resched()) + safe_halt(); + else + local_irq_enable(); } + set_thread_flag(TIF_POLLING_NRFLAG); } /* @@ -201,7 +226,9 @@ void cpu_idle (void) idle = default_idle; if (cpu_is_offline(smp_processor_id())) play_dead(); + enter_idle(); idle(); + __exit_idle(); } preempt_enable_no_resched(); @@ -424,7 +451,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp, struct task_struct *me = current; childregs = ((struct pt_regs *) - (THREAD_SIZE + (unsigned long) p->thread_info)) - 1; + (THREAD_SIZE + task_stack_page(p))) - 1; *childregs = *regs; childregs->rax = 0; @@ -436,7 +463,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long rsp, p->thread.rsp0 = (unsigned long) (childregs+1); p->thread.userrsp = me->thread.userrsp; - set_ti_thread_flag(p->thread_info, TIF_FORK); + set_tsk_thread_flag(p, TIF_FORK); p->thread.fs = me->thread.fs; p->thread.gs = me->thread.gs; @@ -563,7 +590,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) write_pda(oldrsp, next->userrsp); write_pda(pcurrent, next_p); write_pda(kernelstack, - (unsigned long)next_p->thread_info + THREAD_SIZE - PDA_STACKOFFSET); + task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET); /* * Now maybe reload the debug registers @@ -677,7 +704,7 @@ unsigned long get_wchan(struct task_struct *p) if (!p || p == current || p->state==TASK_RUNNING) return 0; - stack = (unsigned long)p->thread_info; + stack = (unsigned long)task_stack_page(p); if (p->thread.rsp < stack || p->thread.rsp > stack+THREAD_SIZE) return 0; fp = *(u64 *)(p->thread.rsp); @@ -795,8 +822,7 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) { struct pt_regs *pp, ptregs; - pp = (struct pt_regs *)(tsk->thread.rsp0); - --pp; + pp = task_pt_regs(tsk); ptregs = *pp; ptregs.cs &= 0xffff; |