summaryrefslogtreecommitdiff
path: root/arch/mips/include/asm/cmpxchg.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/include/asm/cmpxchg.h')
-rw-r--r--arch/mips/include/asm/cmpxchg.h124
1 files changed, 124 insertions, 0 deletions
diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h
index d8d1c28..285a41f 100644
--- a/arch/mips/include/asm/cmpxchg.h
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -9,6 +9,130 @@
#define __ASM_CMPXCHG_H
#include <linux/irqflags.h>
+#include <asm/war.h>
+
+static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
+{
+ __u32 retval;
+
+ smp_mb__before_llsc();
+
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
+ unsigned long dummy;
+
+ __asm__ __volatile__(
+ " .set mips3 \n"
+ "1: ll %0, %3 # xchg_u32 \n"
+ " .set mips0 \n"
+ " move %2, %z4 \n"
+ " .set mips3 \n"
+ " sc %2, %1 \n"
+ " beqzl %2, 1b \n"
+ " .set mips0 \n"
+ : "=&r" (retval), "=m" (*m), "=&r" (dummy)
+ : "R" (*m), "Jr" (val)
+ : "memory");
+ } else if (kernel_uses_llsc) {
+ unsigned long dummy;
+
+ do {
+ __asm__ __volatile__(
+ " .set mips3 \n"
+ " ll %0, %3 # xchg_u32 \n"
+ " .set mips0 \n"
+ " move %2, %z4 \n"
+ " .set mips3 \n"
+ " sc %2, %1 \n"
+ " .set mips0 \n"
+ : "=&r" (retval), "=m" (*m), "=&r" (dummy)
+ : "R" (*m), "Jr" (val)
+ : "memory");
+ } while (unlikely(!dummy));
+ } else {
+ unsigned long flags;
+
+ raw_local_irq_save(flags);
+ retval = *m;
+ *m = val;
+ raw_local_irq_restore(flags); /* implies memory barrier */
+ }
+
+ smp_llsc_mb();
+
+ return retval;
+}
+
+#ifdef CONFIG_64BIT
+static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
+{
+ __u64 retval;
+
+ smp_mb__before_llsc();
+
+ if (kernel_uses_llsc && R10000_LLSC_WAR) {
+ unsigned long dummy;
+
+ __asm__ __volatile__(
+ " .set mips3 \n"
+ "1: lld %0, %3 # xchg_u64 \n"
+ " move %2, %z4 \n"
+ " scd %2, %1 \n"
+ " beqzl %2, 1b \n"
+ " .set mips0 \n"
+ : "=&r" (retval), "=m" (*m), "=&r" (dummy)
+ : "R" (*m), "Jr" (val)
+ : "memory");
+ } else if (kernel_uses_llsc) {
+ unsigned long dummy;
+
+ do {
+ __asm__ __volatile__(
+ " .set mips3 \n"
+ " lld %0, %3 # xchg_u64 \n"
+ " move %2, %z4 \n"
+ " scd %2, %1 \n"
+ " .set mips0 \n"
+ : "=&r" (retval), "=m" (*m), "=&r" (dummy)
+ : "R" (*m), "Jr" (val)
+ : "memory");
+ } while (unlikely(!dummy));
+ } else {
+ unsigned long flags;
+
+ raw_local_irq_save(flags);
+ retval = *m;
+ *m = val;
+ raw_local_irq_restore(flags); /* implies memory barrier */
+ }
+
+ smp_llsc_mb();
+
+ return retval;
+}
+#else
+extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
+#define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
+#endif
+
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+ switch (size) {
+ case 4:
+ return __xchg_u32(ptr, x);
+ case 8:
+ return __xchg_u64(ptr, x);
+ }
+
+ return x;
+}
+
+#define xchg(ptr, x) \
+({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) & ~0xc); \
+ \
+ ((__typeof__(*(ptr))) \
+ __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \
+})
#define __HAVE_ARCH_CMPXCHG 1