1 files changed, 14 insertions, 14 deletions

diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index 4f2c28060c9a..499900781d59 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -5,21 +5,13 @@
 #error SMP not supported on pre-ARMv6 CPUs
 #endif
 
-#include <asm/processor.h>
+#include <linux/prefetch.h>
 
 /*
  * sev and wfe are ARMv6K extensions.  Uniprocessor ARMv6 may not have the K
  * extensions, so when running on UP, we have to patch these instructions away.
  */
-#define ALT_SMP(smp, up)                                        \
-        "9998:  " smp "\n"                                      \
-        "       .pushsection \".alt.smp.init\", \"a\"\n"        \
-        "       .long   9998b\n"                                \
-        "       " up "\n"                                       \
-        "       .popsection\n"
-
 #ifdef CONFIG_THUMB2_KERNEL
-#define SEV             ALT_SMP("sev.w", "nop.w")
 /*
  * For Thumb-2, special care is needed to ensure that the conditional WFE
  * instruction really does assemble to exactly 4 bytes (as required by
@@ -31,17 +23,18 @@
  * the assembler won't change IT instructions which are explicitly present
  * in the input.
  */
-#define WFE(cond)       ALT_SMP(                \
+#define WFE(cond)       __ALT_SMP_ASM(          \
         "it " cond "\n\t"                       \
         "wfe" cond ".n",                        \
                                                 \
         "nop.w"                                 \
 )
 #else
-#define SEV             ALT_SMP("sev", "nop")
-#define WFE(cond)       ALT_SMP("wfe" cond, "nop")
+#define WFE(cond)       __ALT_SMP_ASM("wfe" cond, "nop")
 #endif
 
+#define SEV             __ALT_SMP_ASM(WASM(sev), WASM(nop))
+
 static inline void dsb_sev(void)
 {
 #if __LINUX_ARM_ARCH__ >= 7
@@ -77,6 +70,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
         u32 newval;
         arch_spinlock_t lockval;
 
+        prefetchw(&lock->slock);
         __asm__ __volatile__(
 "1:     ldrex   %0, [%3]\n"
 "       add     %1, %0, %4\n"
@@ -100,6 +94,7 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock)
         unsigned long contended, res;
         u32 slock;
 
+        prefetchw(&lock->slock);
         do {
                 __asm__ __volatile__(
                 "       ldrex   %0, [%3]\n"
@@ -152,6 +147,7 @@ static inline void arch_write_lock(arch_rwlock_t *rw)
 {
         unsigned long tmp;
 
+        prefetchw(&rw->lock);
         __asm__ __volatile__(
 "1:     ldrex   %0, [%1]\n"
 "       teq     %0, #0\n"
@@ -170,6 +166,7 @@ static inline int arch_write_trylock(arch_rwlock_t *rw)
 {
         unsigned long contended, res;
 
+        prefetchw(&rw->lock);
         do {
                 __asm__ __volatile__(
                 "       ldrex   %0, [%2]\n"
@@ -203,7 +200,7 @@ static inline void arch_write_unlock(arch_rwlock_t *rw)
 }
 
 /* write_can_lock - would write_trylock() succeed? */
-#define arch_write_can_lock(x)          ((x)->lock == 0)
+#define arch_write_can_lock(x)          (ACCESS_ONCE((x)->lock) == 0)
 
 /*
  * Read locks are a bit more hairy:
@@ -221,6 +218,7 @@ static inline void arch_read_lock(arch_rwlock_t *rw)
 {
         unsigned long tmp, tmp2;
 
+        prefetchw(&rw->lock);
         __asm__ __volatile__(
 "1:     ldrex   %0, [%2]\n"
 "       adds    %0, %0, #1\n"
@@ -241,6 +239,7 @@ static inline void arch_read_unlock(arch_rwlock_t *rw)
 
         smp_mb();
 
+        prefetchw(&rw->lock);
         __asm__ __volatile__(
 "1:     ldrex   %0, [%2]\n"
 "       sub     %0, %0, #1\n"
@@ -259,6 +258,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
 {
         unsigned long contended, res;
 
+        prefetchw(&rw->lock);
         do {
                 __asm__ __volatile__(
                 "       ldrex   %0, [%2]\n"
@@ -280,7 +280,7 @@ static inline int arch_read_trylock(arch_rwlock_t *rw)
 }
 
 /* read_can_lock - would read_trylock() succeed? */
-#define arch_read_can_lock(x)           ((x)->lock < 0x80000000)
+#define arch_read_can_lock(x)           (ACCESS_ONCE((x)->lock) < 0x80000000)
 
 #define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
 #define arch_write_lock_flags(lock, flags) arch_write_lock(lock)