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-rw-r--r--arch/x86/include/asm/apic.h3
-rw-r--r--arch/x86/kernel/apic/apic.c17
2 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index aa5b2eec3602..ff8dff645e80 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -469,6 +469,8 @@ static inline u32 safe_apic_wait_icr_idle(void)
return apic->safe_wait_icr_idle();
}
+extern void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v));
+
#else /* CONFIG_X86_LOCAL_APIC */
static inline u32 apic_read(u32 reg) { return 0; }
@@ -478,6 +480,7 @@ static inline u64 apic_icr_read(void) { return 0; }
static inline void apic_icr_write(u32 low, u32 high) { }
static inline void apic_wait_icr_idle(void) { }
static inline u32 safe_apic_wait_icr_idle(void) { return 0; }
+static inline void apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v)) {}
#endif /* CONFIG_X86_LOCAL_APIC */
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 39a222e094af..c7520b6184ef 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2124,6 +2124,23 @@ void default_init_apic_ldr(void)
}
/*
+ * Override the generic EOI implementation with an optimized version.
+ * Only called during early boot when only one CPU is active and with
+ * interrupts disabled, so we know this does not race with actual APIC driver
+ * use.
+ */
+void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
+{
+ struct apic **drv;
+
+ for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
+ /* Should happen once for each apic */
+ WARN_ON((*drv)->eoi_write == eoi_write);
+ (*drv)->eoi_write = eoi_write;
+ }
+}
+
+/*
* Power management
*/
#ifdef CONFIG_PM