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Diffstat (limited to 'arch/powerpc/include/asm/cmpxchg.h')
-rw-r--r--arch/powerpc/include/asm/cmpxchg.h237
1 files changed, 183 insertions, 54 deletions
diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h
index d1a8d93cccfd..44efe739b6b9 100644
--- a/arch/powerpc/include/asm/cmpxchg.h
+++ b/arch/powerpc/include/asm/cmpxchg.h
@@ -5,25 +5,25 @@
#include <linux/compiler.h>
#include <asm/synch.h>
#include <asm/asm-compat.h>
+#include <linux/bug.h>
/*
* Atomic exchange
*
- * Changes the memory location '*ptr' to be val and returns
+ * Changes the memory location '*p' to be val and returns
* the previous value stored there.
*/
+
static __always_inline unsigned long
-__xchg_u32(volatile void *p, unsigned long val)
+__xchg_u32_local(volatile void *p, unsigned long val)
{
unsigned long prev;
__asm__ __volatile__(
- PPC_ATOMIC_ENTRY_BARRIER
"1: lwarx %0,0,%2 \n"
PPC405_ERR77(0,%2)
" stwcx. %3,0,%2 \n\
bne- 1b"
- PPC_ATOMIC_EXIT_BARRIER
: "=&r" (prev), "+m" (*(volatile unsigned int *)p)
: "r" (p), "r" (val)
: "cc", "memory");
@@ -31,42 +31,34 @@ __xchg_u32(volatile void *p, unsigned long val)
return prev;
}
-/*
- * Atomic exchange
- *
- * Changes the memory location '*ptr' to be val and returns
- * the previous value stored there.
- */
static __always_inline unsigned long
-__xchg_u32_local(volatile void *p, unsigned long val)
+__xchg_u32_relaxed(u32 *p, unsigned long val)
{
unsigned long prev;
__asm__ __volatile__(
-"1: lwarx %0,0,%2 \n"
- PPC405_ERR77(0,%2)
-" stwcx. %3,0,%2 \n\
- bne- 1b"
- : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+"1: lwarx %0,0,%2\n"
+ PPC405_ERR77(0, %2)
+" stwcx. %3,0,%2\n"
+" bne- 1b"
+ : "=&r" (prev), "+m" (*p)
: "r" (p), "r" (val)
- : "cc", "memory");
+ : "cc");
return prev;
}
#ifdef CONFIG_PPC64
static __always_inline unsigned long
-__xchg_u64(volatile void *p, unsigned long val)
+__xchg_u64_local(volatile void *p, unsigned long val)
{
unsigned long prev;
__asm__ __volatile__(
- PPC_ATOMIC_ENTRY_BARRIER
"1: ldarx %0,0,%2 \n"
PPC405_ERR77(0,%2)
" stdcx. %3,0,%2 \n\
bne- 1b"
- PPC_ATOMIC_EXIT_BARRIER
: "=&r" (prev), "+m" (*(volatile unsigned long *)p)
: "r" (p), "r" (val)
: "cc", "memory");
@@ -75,64 +67,52 @@ __xchg_u64(volatile void *p, unsigned long val)
}
static __always_inline unsigned long
-__xchg_u64_local(volatile void *p, unsigned long val)
+__xchg_u64_relaxed(u64 *p, unsigned long val)
{
unsigned long prev;
__asm__ __volatile__(
-"1: ldarx %0,0,%2 \n"
- PPC405_ERR77(0,%2)
-" stdcx. %3,0,%2 \n\
- bne- 1b"
- : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+"1: ldarx %0,0,%2\n"
+ PPC405_ERR77(0, %2)
+" stdcx. %3,0,%2\n"
+" bne- 1b"
+ : "=&r" (prev), "+m" (*p)
: "r" (p), "r" (val)
- : "cc", "memory");
+ : "cc");
return prev;
}
#endif
-/*
- * This function doesn't exist, so you'll get a linker error
- * if something tries to do an invalid xchg().
- */
-extern void __xchg_called_with_bad_pointer(void);
-
static __always_inline unsigned long
-__xchg(volatile void *ptr, unsigned long x, unsigned int size)
+__xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
{
switch (size) {
case 4:
- return __xchg_u32(ptr, x);
+ return __xchg_u32_local(ptr, x);
#ifdef CONFIG_PPC64
case 8:
- return __xchg_u64(ptr, x);
+ return __xchg_u64_local(ptr, x);
#endif
}
- __xchg_called_with_bad_pointer();
+ BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg");
return x;
}
static __always_inline unsigned long
-__xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
+__xchg_relaxed(void *ptr, unsigned long x, unsigned int size)
{
switch (size) {
case 4:
- return __xchg_u32_local(ptr, x);
+ return __xchg_u32_relaxed(ptr, x);
#ifdef CONFIG_PPC64
case 8:
- return __xchg_u64_local(ptr, x);
+ return __xchg_u64_relaxed(ptr, x);
#endif
}
- __xchg_called_with_bad_pointer();
+ BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local");
return x;
}
-#define xchg(ptr,x) \
- ({ \
- __typeof__(*(ptr)) _x_ = (x); \
- (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
- })
-
#define xchg_local(ptr,x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
@@ -140,6 +120,12 @@ __xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
(unsigned long)_x_, sizeof(*(ptr))); \
})
+#define xchg_relaxed(ptr, x) \
+({ \
+ __typeof__(*(ptr)) _x_ = (x); \
+ (__typeof__(*(ptr))) __xchg_relaxed((ptr), \
+ (unsigned long)_x_, sizeof(*(ptr))); \
+})
/*
* Compare and exchange - if *p == old, set it to new,
* and return the old value of *p.
@@ -190,6 +176,56 @@ __cmpxchg_u32_local(volatile unsigned int *p, unsigned long old,
return prev;
}
+static __always_inline unsigned long
+__cmpxchg_u32_relaxed(u32 *p, unsigned long old, unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+"1: lwarx %0,0,%2 # __cmpxchg_u32_relaxed\n"
+" cmpw 0,%0,%3\n"
+" bne- 2f\n"
+ PPC405_ERR77(0, %2)
+" stwcx. %4,0,%2\n"
+" bne- 1b\n"
+"2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc");
+
+ return prev;
+}
+
+/*
+ * cmpxchg family don't have order guarantee if cmp part fails, therefore we
+ * can avoid superfluous barriers if we use assembly code to implement
+ * cmpxchg() and cmpxchg_acquire(), however we don't do the similar for
+ * cmpxchg_release() because that will result in putting a barrier in the
+ * middle of a ll/sc loop, which is probably a bad idea. For example, this
+ * might cause the conditional store more likely to fail.
+ */
+static __always_inline unsigned long
+__cmpxchg_u32_acquire(u32 *p, unsigned long old, unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+"1: lwarx %0,0,%2 # __cmpxchg_u32_acquire\n"
+" cmpw 0,%0,%3\n"
+" bne- 2f\n"
+ PPC405_ERR77(0, %2)
+" stwcx. %4,0,%2\n"
+" bne- 1b\n"
+ PPC_ACQUIRE_BARRIER
+ "\n"
+"2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+
#ifdef CONFIG_PPC64
static __always_inline unsigned long
__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
@@ -233,11 +269,47 @@ __cmpxchg_u64_local(volatile unsigned long *p, unsigned long old,
return prev;
}
-#endif
-/* This function doesn't exist, so you'll get a linker error
- if something tries to do an invalid cmpxchg(). */
-extern void __cmpxchg_called_with_bad_pointer(void);
+static __always_inline unsigned long
+__cmpxchg_u64_relaxed(u64 *p, unsigned long old, unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+"1: ldarx %0,0,%2 # __cmpxchg_u64_relaxed\n"
+" cmpd 0,%0,%3\n"
+" bne- 2f\n"
+" stdcx. %4,0,%2\n"
+" bne- 1b\n"
+"2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc");
+
+ return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u64_acquire(u64 *p, unsigned long old, unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+"1: ldarx %0,0,%2 # __cmpxchg_u64_acquire\n"
+" cmpd 0,%0,%3\n"
+" bne- 2f\n"
+" stdcx. %4,0,%2\n"
+" bne- 1b\n"
+ PPC_ACQUIRE_BARRIER
+ "\n"
+"2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+#endif
static __always_inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
@@ -251,7 +323,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
return __cmpxchg_u64(ptr, old, new);
#endif
}
- __cmpxchg_called_with_bad_pointer();
+ BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg");
return old;
}
@@ -267,10 +339,41 @@ __cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
return __cmpxchg_u64_local(ptr, old, new);
#endif
}
- __cmpxchg_called_with_bad_pointer();
+ BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_local");
+ return old;
+}
+
+static __always_inline unsigned long
+__cmpxchg_relaxed(void *ptr, unsigned long old, unsigned long new,
+ unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32_relaxed(ptr, old, new);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __cmpxchg_u64_relaxed(ptr, old, new);
+#endif
+ }
+ BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_relaxed");
return old;
}
+static __always_inline unsigned long
+__cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new,
+ unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32_acquire(ptr, old, new);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __cmpxchg_u64_acquire(ptr, old, new);
+#endif
+ }
+ BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_acquire");
+ return old;
+}
#define cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
@@ -288,6 +391,23 @@ __cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
(unsigned long)_n_, sizeof(*(ptr))); \
})
+#define cmpxchg_relaxed(ptr, o, n) \
+({ \
+ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg_relaxed((ptr), \
+ (unsigned long)_o_, (unsigned long)_n_, \
+ sizeof(*(ptr))); \
+})
+
+#define cmpxchg_acquire(ptr, o, n) \
+({ \
+ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg_acquire((ptr), \
+ (unsigned long)_o_, (unsigned long)_n_, \
+ sizeof(*(ptr))); \
+})
#ifdef CONFIG_PPC64
#define cmpxchg64(ptr, o, n) \
({ \
@@ -299,7 +419,16 @@ __cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg_local((ptr), (o), (n)); \
})
-#define cmpxchg64_relaxed cmpxchg64_local
+#define cmpxchg64_relaxed(ptr, o, n) \
+({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg_relaxed((ptr), (o), (n)); \
+})
+#define cmpxchg64_acquire(ptr, o, n) \
+({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg_acquire((ptr), (o), (n)); \
+})
#else
#include <asm-generic/cmpxchg-local.h>
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 11:02:50 +0000