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-rw-r--r--arch/i386/kernel/apic.c4
-rw-r--r--arch/i386/kernel/cpu/mcheck/p4.c2
-rw-r--r--arch/i386/kernel/irq.c3
-rw-r--r--arch/i386/kernel/process.c53
-rw-r--r--arch/i386/kernel/smp.c2
-rw-r--r--include/asm-i386/idle.h14
-rw-r--r--include/asm-i386/processor.h8
7 files changed, 85 insertions, 1 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 629c5ed94260..f4159e0a7ae9 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -36,6 +36,7 @@
#include <asm/hpet.h>
#include <asm/i8253.h>
#include <asm/nmi.h>
+#include <asm/idle.h>
#include <mach_apic.h>
#include <mach_apicdef.h>
@@ -1255,6 +1256,7 @@ fastcall void smp_apic_timer_interrupt(struct pt_regs *regs)
* Besides, if we don't timer interrupts ignore the global
* interrupt lock, which is the WrongThing (tm) to do.
*/
+ exit_idle();
irq_enter();
smp_local_timer_interrupt();
irq_exit();
@@ -1305,6 +1307,7 @@ fastcall void smp_spurious_interrupt(struct pt_regs *regs)
{
unsigned long v;
+ exit_idle();
irq_enter();
/*
* Check if this really is a spurious interrupt and ACK it
@@ -1329,6 +1332,7 @@ fastcall void smp_error_interrupt(struct pt_regs *regs)
{
unsigned long v, v1;
+ exit_idle();
irq_enter();
/* First tickle the hardware, only then report what went on. -- REW */
v = apic_read(APIC_ESR);
diff --git a/arch/i386/kernel/cpu/mcheck/p4.c b/arch/i386/kernel/cpu/mcheck/p4.c
index 504434a46011..8359c19d3a23 100644
--- a/arch/i386/kernel/cpu/mcheck/p4.c
+++ b/arch/i386/kernel/cpu/mcheck/p4.c
@@ -12,6 +12,7 @@
#include <asm/system.h>
#include <asm/msr.h>
#include <asm/apic.h>
+#include <asm/idle.h>
#include <asm/therm_throt.h>
@@ -59,6 +60,7 @@ static void (*vendor_thermal_interrupt)(struct pt_regs *regs) = unexpected_therm
fastcall void smp_thermal_interrupt(struct pt_regs *regs)
{
+ exit_idle();
irq_enter();
vendor_thermal_interrupt(regs);
irq_exit();
diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
index 3201d421090a..5785d84103a6 100644
--- a/arch/i386/kernel/irq.c
+++ b/arch/i386/kernel/irq.c
@@ -19,6 +19,8 @@
#include <linux/cpu.h>
#include <linux/delay.h>
+#include <asm/idle.h>
+
DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp;
EXPORT_PER_CPU_SYMBOL(irq_stat);
@@ -61,6 +63,7 @@ fastcall unsigned int do_IRQ(struct pt_regs *regs)
union irq_ctx *curctx, *irqctx;
u32 *isp;
#endif
+ exit_idle();
if (unlikely((unsigned)irq >= NR_IRQS)) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 05be77413351..7845d480c293 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -48,6 +48,7 @@
#include <asm/i387.h>
#include <asm/desc.h>
#include <asm/vm86.h>
+#include <asm/idle.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
@@ -80,6 +81,42 @@ void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);
static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
+static ATOMIC_NOTIFIER_HEAD(idle_notifier);
+
+void idle_notifier_register(struct notifier_block *n)
+{
+ atomic_notifier_chain_register(&idle_notifier, n);
+}
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+ atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+
+static DEFINE_PER_CPU(volatile unsigned long, idle_state);
+
+void enter_idle(void)
+{
+ /* needs to be atomic w.r.t. interrupts, not against other CPUs */
+ __set_bit(0, &__get_cpu_var(idle_state));
+ atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
+}
+
+static void __exit_idle(void)
+{
+ /* needs to be atomic w.r.t. interrupts, not against other CPUs */
+ if (__test_and_clear_bit(0, &__get_cpu_var(idle_state)) == 0)
+ return;
+ atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
+}
+
+void exit_idle(void)
+{
+ if (current->pid)
+ return;
+ __exit_idle();
+}
+
void disable_hlt(void)
{
hlt_counter++;
@@ -130,6 +167,7 @@ EXPORT_SYMBOL(default_idle);
*/
static void poll_idle (void)
{
+ local_irq_enable();
cpu_relax();
}
@@ -189,7 +227,16 @@ void cpu_idle(void)
play_dead();
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
+
+ /*
+ * Idle routines should keep interrupts disabled
+ * from here on, until they go to idle.
+ * Otherwise, idle callbacks can misfire.
+ */
+ local_irq_disable();
+ enter_idle();
idle();
+ __exit_idle();
}
preempt_enable_no_resched();
schedule();
@@ -243,7 +290,11 @@ void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();
if (!need_resched())
- __mwait(eax, ecx);
+ __sti_mwait(eax, ecx);
+ else
+ local_irq_enable();
+ } else {
+ local_irq_enable();
}
}
diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
index 5285aff8367f..ffc4f65c5189 100644
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -23,6 +23,7 @@
#include <asm/mtrr.h>
#include <asm/tlbflush.h>
+#include <asm/idle.h>
#include <mach_apic.h>
/*
@@ -624,6 +625,7 @@ fastcall void smp_call_function_interrupt(struct pt_regs *regs)
/*
* At this point the info structure may be out of scope unless wait==1
*/
+ exit_idle();
irq_enter();
(*func)(info);
irq_exit();
diff --git a/include/asm-i386/idle.h b/include/asm-i386/idle.h
new file mode 100644
index 000000000000..87ab93911199
--- /dev/null
+++ b/include/asm-i386/idle.h
@@ -0,0 +1,14 @@
+#ifndef _ASM_I386_IDLE_H
+#define _ASM_I386_IDLE_H 1
+
+#define IDLE_START 1
+#define IDLE_END 2
+
+struct notifier_block;
+void idle_notifier_register(struct notifier_block *n);
+void idle_notifier_unregister(struct notifier_block *n);
+
+void exit_idle(void);
+void enter_idle(void);
+
+#endif
diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 11bf899de8aa..edfbe46a5e13 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -257,6 +257,14 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
: :"a" (eax), "c" (ecx));
}
+static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
+{
+ /* "mwait %eax,%ecx;" */
+ asm volatile(
+ "sti; .byte 0x0f,0x01,0xc9;"
+ : :"a" (eax), "c" (ecx));
+}
+
extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx);
/* from system description table in BIOS. Mostly for MCA use, but
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-07 11:54:09 +0000