diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2012-05-16 19:03:52 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-05-18 09:46:08 +0200 |
| commit | 2a43195d831997551da93e6b3c22c965e93fe9cc (patch) | |
| tree | b7ad184a43adb4018aab793efda8524b5ba5e280 /arch/x86/include/asm/apic.h | |
| parent | 4ebcc243901c48ee3baba6bdf179c7315fa8806f (diff) | |
x86/apic: Add apic->eoi_write() callback
Add eoi_write callback so that kvm can override
eoi accesses without touching the rest of the apic.
As a side-effect, this will enable a micro-optimization
for apics using msr.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: gleb@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/0df425d746c49ac2ecc405174df87752869629d2.1337184153.git.mst@redhat.com
[ tidied it up a bit ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/apic.h')
| -rw-r--r-- | arch/x86/include/asm/apic.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index a09e9ab0bbdf..bf8d065dd977 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -351,6 +351,14 @@ struct apic { /* apic ops */ u32 (*read)(u32 reg); void (*write)(u32 reg, u32 v); + /* + * ->eoi_write() has the same signature as ->write(). + * + * Drivers can support both ->eoi_write() and ->write() by passing the same + * callback value. Kernel can override ->eoi_write() and fall back + * on write for EOI. + */ + void (*eoi_write)(u32 reg, u32 v); u64 (*icr_read)(void); void (*icr_write)(u32 low, u32 high); void (*wait_icr_idle)(void); @@ -426,6 +434,11 @@ static inline void apic_write(u32 reg, u32 val) apic->write(reg, val); } +static inline void apic_eoi(void) +{ + apic->eoi_write(APIC_EOI, APIC_EOI_ACK); +} + static inline u64 apic_icr_read(void) { return apic->icr_read(); @@ -450,6 +463,7 @@ static inline u32 safe_apic_wait_icr_idle(void) static inline u32 apic_read(u32 reg) { return 0; } static inline void apic_write(u32 reg, u32 val) { } +static inline void apic_eoi(void) { } 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) { } @@ -463,7 +477,7 @@ static inline void ack_APIC_irq(void) * ack_APIC_irq() actually gets compiled as a single instruction * ... yummie. */ - apic_write(APIC_EOI, APIC_EOI_ACK); + apic_eoi(); } static inline unsigned default_get_apic_id(unsigned long x) |