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Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r--arch/x86/kernel/process_64.c143
1 files changed, 8 insertions, 135 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index a465973..733ca39 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -14,7 +14,6 @@
* This file handles the architecture-dependent parts of process handling..
*/
-#include <linux/stackprotector.h>
#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
@@ -32,17 +31,15 @@
#include <linux/notifier.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
-#include <linux/tick.h>
#include <linux/prctl.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/ftrace.h>
-#include <linux/cpuidle.h>
#include <asm/pgtable.h>
-#include <asm/system.h>
#include <asm/processor.h>
#include <asm/i387.h>
+#include <asm/fpu-internal.h>
#include <asm/mmu_context.h>
#include <asm/prctl.h>
#include <asm/desc.h>
@@ -51,116 +48,11 @@
#include <asm/idle.h>
#include <asm/syscalls.h>
#include <asm/debugreg.h>
-#include <asm/nmi.h>
+#include <asm/switch_to.h>
asmlinkage extern void ret_from_fork(void);
DEFINE_PER_CPU(unsigned long, old_rsp);
-static DEFINE_PER_CPU(unsigned char, is_idle);
-
-static ATOMIC_NOTIFIER_HEAD(idle_notifier);
-
-void idle_notifier_register(struct notifier_block *n)
-{
- atomic_notifier_chain_register(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_register);
-
-void idle_notifier_unregister(struct notifier_block *n)
-{
- atomic_notifier_chain_unregister(&idle_notifier, n);
-}
-EXPORT_SYMBOL_GPL(idle_notifier_unregister);
-
-void enter_idle(void)
-{
- percpu_write(is_idle, 1);
- atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
-}
-
-static void __exit_idle(void)
-{
- if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
- return;
- atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
-}
-
-/* Called from interrupts to signify idle end */
-void exit_idle(void)
-{
- /* idle loop has pid 0 */
- if (current->pid)
- return;
- __exit_idle();
-}
-
-#ifndef CONFIG_SMP
-static inline void play_dead(void)
-{
- BUG();
-}
-#endif
-
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
-{
- current_thread_info()->status |= TS_POLLING;
-
- /*
- * If we're the non-boot CPU, nothing set the stack canary up
- * for us. CPU0 already has it initialized but no harm in
- * doing it again. This is a good place for updating it, as
- * we wont ever return from this function (so the invalid
- * canaries already on the stack wont ever trigger).
- */
- boot_init_stack_canary();
-
- /* endless idle loop with no priority at all */
- while (1) {
- tick_nohz_idle_enter();
- while (!need_resched()) {
-
- rmb();
-
- if (cpu_is_offline(smp_processor_id()))
- play_dead();
- /*
- * Idle routines should keep interrupts disabled
- * from here on, until they go to idle.
- * Otherwise, idle callbacks can misfire.
- */
- local_touch_nmi();
- local_irq_disable();
- enter_idle();
- /* Don't trace irqs off for idle */
- stop_critical_timings();
-
- /* enter_idle() needs rcu for notifiers */
- rcu_idle_enter();
-
- if (cpuidle_idle_call())
- pm_idle();
-
- rcu_idle_exit();
- start_critical_timings();
-
- /* In many cases the interrupt that ended idle
- has already called exit_idle. But some idle
- loops can be woken up without interrupt. */
- __exit_idle();
- }
-
- tick_nohz_idle_exit();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
- }
-}
/* Prints also some state that isn't saved in the pt_regs */
void __show_regs(struct pt_regs *regs, int all)
@@ -286,6 +178,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
set_tsk_thread_flag(p, TIF_FORK);
+ p->fpu_counter = 0;
p->thread.io_bitmap_ptr = NULL;
savesegment(gs, p->thread.gsindex);
@@ -341,6 +234,7 @@ start_thread_common(struct pt_regs *regs, unsigned long new_ip,
loadsegment(es, _ds);
loadsegment(ds, _ds);
load_gs_index(0);
+ current->thread.usersp = new_sp;
regs->ip = new_ip;
regs->sp = new_sp;
percpu_write(old_rsp, new_sp);
@@ -388,18 +282,9 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
int cpu = smp_processor_id();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
unsigned fsindex, gsindex;
- bool preload_fpu;
+ fpu_switch_t fpu;
- /*
- * If the task has used fpu the last 5 timeslices, just do a full
- * restore of the math state immediately to avoid the trap; the
- * chances of needing FPU soon are obviously high now
- */
- preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;
-
- /* we're going to use this soon, after a few expensive things */
- if (preload_fpu)
- prefetch(next->fpu.state);
+ fpu = switch_fpu_prepare(prev_p, next_p, cpu);
/*
* Reload esp0, LDT and the page table pointer:
@@ -429,13 +314,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
load_TLS(next, cpu);
- /* Must be after DS reload */
- __unlazy_fpu(prev_p);
-
- /* Make sure cpu is ready for new context */
- if (preload_fpu)
- clts();
-
/*
* Leave lazy mode, flushing any hypercalls made here.
* This must be done before restoring TLS segments so
@@ -476,6 +354,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
prev->gsindex = gsindex;
+ switch_fpu_finish(next_p, fpu);
+
/*
* Switch the PDA and FPU contexts.
*/
@@ -494,13 +374,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
__switch_to_xtra(prev_p, next_p, tss);
- /*
- * Preload the FPU context, now that we've determined that the
- * task is likely to be using it.
- */
- if (preload_fpu)
- __math_state_restore();
-
return prev_p;
}

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