[PATCH] ARM SMP: Add ARMv6 memory barriers

Convert explicit gcc asm-based memory barriers into smp_mb() calls.
These change between barrier() and the ARMv6 data memory barrier
instruction depending on whether ARMv6 SMP is enabled.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 24 insertions, 12 deletions

diff --git a/include/asm-arm/locks.h b/include/asm-arm/locks.h
index 9cb33fcc06c1..f08dc8447913 100644
--- a/include/asm-arm/locks.h
+++ b/include/asm-arm/locks.h
@@ -28,7 +28,8 @@
 "       blmi    " #fail                         \
         :                                       \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         })
 
 #define __down_op_ret(ptr,fail)                 \
@@ -48,12 +49,14 @@
 "       mov     %0, ip"                         \
         : "=&r" (ret)                           \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         ret;                                    \
         })
 
 #define __up_op(ptr,wake)                       \
         ({                                      \
+        smp_mb();                               \
         __asm__ __volatile__(                   \
         "@ up_op\n"                             \
 "1:     ldrex   lr, [%0]\n"                     \
@@ -66,7 +69,7 @@
 "       blle    " #wake                         \
         :                                       \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
         })
 
 /*
@@ -92,11 +95,13 @@
 "       blne    " #fail                         \
         :                                       \
         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         })
 
 #define __up_op_write(ptr,wake)                 \
         ({                                      \
+        smp_mb();                               \
         __asm__ __volatile__(                   \
         "@ up_op_read\n"                        \
 "1:     ldrex   lr, [%0]\n"                     \
@@ -108,7 +113,7 @@
 "       blcs    " #wake                         \
         :                                       \
         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
         })
 
 #define __down_op_read(ptr,fail)                \
@@ -116,6 +121,7 @@
 
 #define __up_op_read(ptr,wake)                  \
         ({                                      \
+        smp_mb();                               \
         __asm__ __volatile__(                   \
         "@ up_op_read\n"                        \
 "1:     ldrex   lr, [%0]\n"                     \
@@ -128,7 +134,7 @@
 "       bleq    " #wake                         \
         :                                       \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
         })
 
 #else
@@ -148,7 +154,8 @@
 "       blmi    " #fail                         \
         :                                       \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         })
 
 #define __down_op_ret(ptr,fail)                 \
@@ -169,12 +176,14 @@
 "       mov     %0, ip"                         \
         : "=&r" (ret)                           \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         ret;                                    \
         })
 
 #define __up_op(ptr,wake)                       \
         ({                                      \
+        smp_mb();                               \
         __asm__ __volatile__(                   \
         "@ up_op\n"                             \
 "       mrs     ip, cpsr\n"                     \
@@ -188,7 +197,7 @@
 "       blle    " #wake                         \
         :                                       \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
         })
 
 /*
@@ -215,7 +224,8 @@
 "       blne    " #fail                         \
         :                                       \
         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         })
 
 #define __up_op_write(ptr,wake)                 \
@@ -233,7 +243,8 @@
 "       blcs    " #wake                         \
         :                                       \
         : "r" (ptr), "I" (RW_LOCK_BIAS)         \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
+        smp_mb();                               \
         })
 
 #define __down_op_read(ptr,fail)                \
@@ -241,6 +252,7 @@
 
 #define __up_op_read(ptr,wake)                  \
         ({                                      \
+        smp_mb();                               \
         __asm__ __volatile__(                   \
         "@ up_op_read\n"                        \
 "       mrs     ip, cpsr\n"                     \
@@ -254,7 +266,7 @@
 "       bleq    " #wake                         \
         :                                       \
         : "r" (ptr), "I" (1)                    \
-        : "ip", "lr", "cc", "memory");          \
+        : "ip", "lr", "cc");                    \
         })
 
 #endif