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Diffstat (limited to 'arch/arm64/include/asm/cmpxchg.h')
-rw-r--r--arch/arm64/include/asm/cmpxchg.h84
1 files changed, 19 insertions, 65 deletions
diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index d0cce8068902..60a558127cef 100644
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -21,6 +21,7 @@
#include <linux/bug.h>
#include <linux/mmdebug.h>
+#include <asm/atomic.h>
#include <asm/barrier.h>
#include <asm/lse.h>
@@ -111,74 +112,20 @@ static inline unsigned long __xchg(unsigned long x, volatile void *ptr, int size
static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
- unsigned long oldval = 0, res;
-
switch (size) {
case 1:
- do {
- asm volatile("// __cmpxchg1\n"
- " ldxrb %w1, %2\n"
- " mov %w0, #0\n"
- " cmp %w1, %w3\n"
- " b.ne 1f\n"
- " stxrb %w0, %w4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u8 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
+ return __cmpxchg_case_1(ptr, old, new);
case 2:
- do {
- asm volatile("// __cmpxchg2\n"
- " ldxrh %w1, %2\n"
- " mov %w0, #0\n"
- " cmp %w1, %w3\n"
- " b.ne 1f\n"
- " stxrh %w0, %w4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u16 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
+ return __cmpxchg_case_2(ptr, old, new);
case 4:
- do {
- asm volatile("// __cmpxchg4\n"
- " ldxr %w1, %2\n"
- " mov %w0, #0\n"
- " cmp %w1, %w3\n"
- " b.ne 1f\n"
- " stxr %w0, %w4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u32 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
+ return __cmpxchg_case_4(ptr, old, new);
case 8:
- do {
- asm volatile("// __cmpxchg8\n"
- " ldxr %1, %2\n"
- " mov %w0, #0\n"
- " cmp %1, %3\n"
- " b.ne 1f\n"
- " stxr %w0, %4, %2\n"
- "1:\n"
- : "=&r" (res), "=&r" (oldval), "+Q" (*(u64 *)ptr)
- : "Ir" (old), "r" (new)
- : "cc");
- } while (res);
- break;
-
+ return __cmpxchg_case_8(ptr, old, new);
default:
BUILD_BUG();
}
- return oldval;
+ unreachable();
}
#define system_has_cmpxchg_double() 1
@@ -229,13 +176,20 @@ static inline int __cmpxchg_double_mb(volatile void *ptr1, volatile void *ptr2,
static inline unsigned long __cmpxchg_mb(volatile void *ptr, unsigned long old,
unsigned long new, int size)
{
- unsigned long ret;
-
- smp_mb();
- ret = __cmpxchg(ptr, old, new, size);
- smp_mb();
+ switch (size) {
+ case 1:
+ return __cmpxchg_case_mb_1(ptr, old, new);
+ case 2:
+ return __cmpxchg_case_mb_2(ptr, old, new);
+ case 4:
+ return __cmpxchg_case_mb_4(ptr, old, new);
+ case 8:
+ return __cmpxchg_case_mb_8(ptr, old, new);
+ default:
+ BUILD_BUG();
+ }
- return ret;
+ unreachable();
}
#define cmpxchg(ptr, o, n) \