X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=include%2Fasm-x86%2Fpercpu.h;h=e10a1d0678cfaa014ad702e1169e5d7417240f52;hb=fe47784ba5cbb6b713c013e046859946789b45e4;hp=912a3a17b9db85958abee1464d58e64d798f5f31;hpb=cadc723cc19ce6b881d973d3c04e25ebb83058e6;p=linux-2.6-omap-h63xx.git

diff --git a/include/asm-x86/percpu.h b/include/asm-x86/percpu.h
index 912a3a17b9d..e10a1d0678c 100644
--- a/include/asm-x86/percpu.h
+++ b/include/asm-x86/percpu.h
@@ -1,5 +1,5 @@
-#ifndef _ASM_X86_PERCPU_H_
-#define _ASM_X86_PERCPU_H_
+#ifndef ASM_X86__PERCPU_H
+#define ASM_X86__PERCPU_H
 
 #ifdef CONFIG_X86_64
 #include <linux/compiler.h>
@@ -22,6 +22,32 @@
 
 DECLARE_PER_CPU(struct x8664_pda, pda);
 
+/*
+ * These are supposed to be implemented as a single instruction which
+ * operates on the per-cpu data base segment.  x86-64 doesn't have
+ * that yet, so this is a fairly inefficient workaround for the
+ * meantime.  The single instruction is atomic with respect to
+ * preemption and interrupts, so we need to explicitly disable
+ * interrupts here to achieve the same effect.  However, because it
+ * can be used from within interrupt-disable/enable, we can't actually
+ * disable interrupts; disabling preemption is enough.
+ */
+#define x86_read_percpu(var)						\
+	({								\
+		typeof(per_cpu_var(var)) __tmp;				\
+		preempt_disable();					\
+		__tmp = __get_cpu_var(var);				\
+		preempt_enable();					\
+		__tmp;							\
+	})
+
+#define x86_write_percpu(var, val)					\
+	do {								\
+		preempt_disable();					\
+		__get_cpu_var(var) = (val);				\
+		preempt_enable();					\
+	} while(0)
+
 #else /* CONFIG_X86_64 */
 
 #ifdef __ASSEMBLY__
@@ -156,7 +182,7 @@ do {							\
 	DEFINE_PER_CPU(_type, _name) = _initvalue;			\
 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\
 				{ [0 ... NR_CPUS-1] = _initvalue };	\
-	__typeof__(_type) *_name##_early_ptr = _name##_early_map
+	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map
 
 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
 	EXPORT_PER_CPU_SYMBOL(_name)
@@ -189,4 +215,4 @@ do {							\
 
 #endif	/* !CONFIG_SMP */
 
-#endif /* _ASM_X86_PERCPU_H_ */
+#endif /* ASM_X86__PERCPU_H */