[IA64] pvops: preparation: introduce ia64_get_psr_i() to make kernel paravirtualization friendly.
__local_irq_save() and local_save_flags() are used to mask interruptions.
They read all psr bits that requres whole bit emulation.
On the other hand, reading only psr.i, the single bit, can be virtualized
cheaply.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h
index 0db8c98..927a381 100644
--- a/include/asm-ia64/system.h
+++ b/include/asm-ia64/system.h
@@ -123,10 +123,16 @@
* write a floating-point register right before reading the PSR
* and that writes to PSR.mfl
*/
+#ifdef CONFIG_PARAVIRT
+#define __local_save_flags() ia64_get_psr_i()
+#else
+#define __local_save_flags() ia64_getreg(_IA64_REG_PSR)
+#endif
+
#define __local_irq_save(x) \
do { \
ia64_stop(); \
- (x) = ia64_getreg(_IA64_REG_PSR); \
+ (x) = __local_save_flags(); \
ia64_stop(); \
ia64_rsm(IA64_PSR_I); \
} while (0)
@@ -174,7 +180,7 @@
#endif /* !CONFIG_IA64_DEBUG_IRQ */
#define local_irq_enable() ({ ia64_stop(); ia64_ssm(IA64_PSR_I); ia64_srlz_d(); })
-#define local_save_flags(flags) ({ ia64_stop(); (flags) = ia64_getreg(_IA64_REG_PSR); })
+#define local_save_flags(flags) ({ ia64_stop(); (flags) = __local_save_flags(); })
#define irqs_disabled() \
({ \