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| author | Michael S. Tsirkin <mst@redhat.com> | 2012-04-18 12:57:10 +0300 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2012-05-02 17:51:54 +0300 |
| commit | 315f16edd5c47083d5b77d36ed2437e8b00a7e99 (patch) | |
| tree | 514797139541e5ba326dbc6e57ced668bf46e91f | |
| parent | b8ff9b91fc10d290097eb01a2d3d47de01141d60 (diff) | |
| download | vhost-315f16edd5c47083d5b77d36ed2437e8b00a7e99.tar.gz | |
x86: eoi micro-optimization
We know both register and value for eoi beforehand,
so there's no need to check it and no need to do math
to calculate the msr. Saves instructions/branches
on each EOI when using x2apic.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/apic.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/x2apic_cluster.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/x2apic_phys.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/x2apic_uv_x.c | 2 |
4 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 74efb8df8d7cf4..5eb6d56ab34e1c 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -138,6 +138,11 @@ static inline void native_apic_msr_write(u32 reg, u32 v) wrmsr(APIC_BASE_MSR + (reg >> 4), v, 0); } +static inline void native_apic_msr_eoi_write(u32 reg, u32 v) +{ + wrmsr(APIC_BASE_MSR + (APIC_EOI >> 4), APIC_EOI_ACK, 0); +} + static inline u32 native_apic_msr_read(u32 reg) { u64 msr; diff --git a/arch/x86/kernel/apic/x2apic_cluster.c b/arch/x86/kernel/apic/x2apic_cluster.c index a5baa785a25136..ff35cff0e1a7e6 100644 --- a/arch/x86/kernel/apic/x2apic_cluster.c +++ b/arch/x86/kernel/apic/x2apic_cluster.c @@ -260,7 +260,7 @@ static struct apic apic_x2apic_cluster = { .read = native_apic_msr_read, .write = native_apic_msr_write, - .eoi_write = native_apic_msr_write, + .eoi_write = native_apic_msr_eoi_write, .icr_read = native_x2apic_icr_read, .icr_write = native_x2apic_icr_write, .wait_icr_idle = native_x2apic_wait_icr_idle, diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c index 834035666b8dbb..c17e982db2759a 100644 --- a/arch/x86/kernel/apic/x2apic_phys.c +++ b/arch/x86/kernel/apic/x2apic_phys.c @@ -172,7 +172,7 @@ static struct apic apic_x2apic_phys = { .read = native_apic_msr_read, .write = native_apic_msr_write, - .eoi_write = native_apic_msr_write, + .eoi_write = native_apic_msr_eoi_write, .icr_read = native_x2apic_icr_read, .icr_write = native_x2apic_icr_write, .wait_icr_idle = native_x2apic_wait_icr_idle, diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 5b0e3d0a3d2d3d..c6d03f7a440132 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -404,7 +404,7 @@ static struct apic __refdata apic_x2apic_uv_x = { .read = native_apic_msr_read, .write = native_apic_msr_write, - .eoi_write = native_apic_msr_write, + .eoi_write = native_apic_msr_eoi_write, .icr_read = native_x2apic_icr_read, .icr_write = native_x2apic_icr_write, .wait_icr_idle = native_x2apic_wait_icr_idle, |