From 72cb4256c7574e1c2c1350fa92eecd7cef9e4772 Mon Sep 17 00:00:00 2001
From: Isaku Yamahata <yamahata@valinux.co.jp>
Date: Mon, 19 May 2008 22:13:31 +0900
Subject: [PATCH] [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>
---
include/asm-ia64/intrinsics.h | 2 ++
include/asm-ia64/system.h | 10 ++++++++--
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/include/asm-ia64/intrinsics.h b/include/asm-ia64/intrinsics.h
index 9b83f8f01678..a3b96892f83f 100644
--- a/include/asm-ia64/intrinsics.h
+++ b/include/asm-ia64/intrinsics.h
@@ -18,6 +18,8 @@
# include <asm/gcc_intrin.h>
#endif
+#define ia64_get_psr_i() (ia64_getreg(_IA64_REG_PSR) & IA64_PSR_I)
+
#define ia64_set_rr0_to_rr4(val0, val1, val2, val3, val4) \
do { \
ia64_set_rr(0x0000000000000000UL, (val0)); \
diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h
index 0db8c9812ceb..927a381c20ca 100644
--- a/include/asm-ia64/system.h
+++ b/include/asm-ia64/system.h
@@ -123,10 +123,16 @@ extern struct ia64_boot_param {
* 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 @@ do { \
#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() \
({ \