x86, asm: Introduce and use percpu_inc()

... generating slightly smaller code.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4BCF261F020000780003B33C@vpn.id2.novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 66a272dfd8b8..0ec6d12d84e6 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -190,6 +190,29 @@ do {									\
         pfo_ret__;                                      \
 })
 
+#define percpu_unary_op(op, var)                        \
+({                                                      \
+        switch (sizeof(var)) {                          \
+        case 1:                                         \
+                asm(op "b "__percpu_arg(0)              \
+                    : "+m" (var));                      \
+                break;                                  \
+        case 2:                                         \
+                asm(op "w "__percpu_arg(0)              \
+                    : "+m" (var));                      \
+                break;                                  \
+        case 4:                                         \
+                asm(op "l "__percpu_arg(0)              \
+                    : "+m" (var));                      \
+                break;                                  \
+        case 8:                                         \
+                asm(op "q "__percpu_arg(0)              \
+                    : "+m" (var));                      \
+                break;                                  \
+        default: __bad_percpu_size();                   \
+        }                                               \
+})
+
 /*
  * percpu_read() makes gcc load the percpu variable every time it is
  * accessed while percpu_read_stable() allows the value to be cached.
@@ -207,6 +230,7 @@ do {									\
 #define percpu_and(var, val)            percpu_to_op("and", var, val)
 #define percpu_or(var, val)             percpu_to_op("or", var, val)
 #define percpu_xor(var, val)            percpu_to_op("xor", var, val)
+#define percpu_inc(var)         percpu_unary_op("inc", var)
 
 #define __this_cpu_read_1(pcp)          percpu_from_op("mov", (pcp), "m"(pcp))
 #define __this_cpu_read_2(pcp)          percpu_from_op("mov", (pcp), "m"(pcp))