powerpc: Replace mfmsr instructions with load from PACA kernel_msr field

On 64-bit, the mfmsr instruction can be quite slow, slower
than loading a field from the cache-hot PACA, which happens
to already contain the value we want in most cases.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2012-03-02 11:33:52 +11:00
parent 9424fabf86
commit d9ada91ae2
4 changed files with 10 additions and 15 deletions

View file

@ -68,8 +68,8 @@ static inline bool arch_irqs_disabled(void)
#define __hard_irq_enable() asm volatile("wrteei 1" : : : "memory");
#define __hard_irq_disable() asm volatile("wrteei 0" : : : "memory");
#else
#define __hard_irq_enable() __mtmsrd(mfmsr() | MSR_EE, 1)
#define __hard_irq_disable() __mtmsrd(mfmsr() & ~MSR_EE, 1)
#define __hard_irq_enable() __mtmsrd(local_paca->kernel_msr | MSR_EE, 1)
#define __hard_irq_disable() __mtmsrd(local_paca->kernel_msr, 1)
#endif
#define hard_irq_disable() \