x86: convert pda ops to wrappers around x86 percpu accessors
pda is now a percpu variable and there's no reason it can't use plain
x86 percpu accessors. Add x86_test_and_clear_bit_percpu() and replace
pda op implementations with wrappers around x86 percpu accessors.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 556f84b..328b31a 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -121,6 +121,16 @@
#define x86_sub_percpu(var, val) percpu_to_op("sub", per_cpu__##var, val)
#define x86_or_percpu(var, val) percpu_to_op("or", per_cpu__##var, val)
+/* This is not atomic against other CPUs -- CPU preemption needs to be off */
+#define x86_test_and_clear_bit_percpu(bit, var) \
+({ \
+ int old__; \
+ asm volatile("btr %1,"__percpu_seg_str"%c2\n\tsbbl %0,%0" \
+ : "=r" (old__) \
+ : "dIr" (bit), "i" (&per_cpu__##var) : "memory"); \
+ old__; \
+})
+
#ifdef CONFIG_X86_64
extern void load_pda_offset(int cpu);
#else
