summaryrefslogtreecommitdiffstats
path: root/include/asm-generic/percpu.h
diff options
context:
space:
mode:
authorLen Brown <len.brown@intel.com>2009-04-05 02:14:15 -0400
committerLen Brown <len.brown@intel.com>2009-04-05 02:14:15 -0400
commit478c6a43fcbc6c11609f8cee7c7b57223907754f (patch)
treea7f7952099da60d33032aed6de9c0c56c9f8779e /include/asm-generic/percpu.h
parent8a3f257c704e02aee9869decd069a806b45be3f1 (diff)
parent6bb597507f9839b13498781e481f5458aea33620 (diff)
downloadtalos-op-linux-478c6a43fcbc6c11609f8cee7c7b57223907754f.tar.gz
talos-op-linux-478c6a43fcbc6c11609f8cee7c7b57223907754f.zip
Merge branch 'linus' into release
Conflicts: arch/x86/kernel/cpu/cpufreq/longhaul.c Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'include/asm-generic/percpu.h')
-rw-r--r--include/asm-generic/percpu.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index b0e63c672ebd..00f45ff081a6 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -80,4 +80,56 @@ extern void setup_per_cpu_areas(void);
#define DECLARE_PER_CPU(type, name) extern PER_CPU_ATTRIBUTES \
__typeof__(type) per_cpu_var(name)
+/*
+ * Optional methods for optimized non-lvalue per-cpu variable access.
+ *
+ * @var can be a percpu variable or a field of it and its size should
+ * equal char, int or long. percpu_read() evaluates to a lvalue and
+ * all others to void.
+ *
+ * These operations are guaranteed to be atomic w.r.t. preemption.
+ * The generic versions use plain get/put_cpu_var(). Archs are
+ * encouraged to implement single-instruction alternatives which don't
+ * require preemption protection.
+ */
+#ifndef percpu_read
+# define percpu_read(var) \
+ ({ \
+ typeof(per_cpu_var(var)) __tmp_var__; \
+ __tmp_var__ = get_cpu_var(var); \
+ put_cpu_var(var); \
+ __tmp_var__; \
+ })
+#endif
+
+#define __percpu_generic_to_op(var, val, op) \
+do { \
+ get_cpu_var(var) op val; \
+ put_cpu_var(var); \
+} while (0)
+
+#ifndef percpu_write
+# define percpu_write(var, val) __percpu_generic_to_op(var, (val), =)
+#endif
+
+#ifndef percpu_add
+# define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=)
+#endif
+
+#ifndef percpu_sub
+# define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=)
+#endif
+
+#ifndef percpu_and
+# define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=)
+#endif
+
+#ifndef percpu_or
+# define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=)
+#endif
+
+#ifndef percpu_xor
+# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
+#endif
+
#endif /* _ASM_GENERIC_PERCPU_H_ */
OpenPOWER on IntegriCloud