From: Stephen Hemminger <step...@networkplumber.org>
To handle atomic update of link status (64 bit), every driver
was doing its own version using cmpset.
Atomic exchange is a useful primitive in its own right;
therefore make it a EAL routine.
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
Reviewed-by: Ferruh Yigit <ferruh.yi...@intel.com>
---
v6:
*fix build error caused by rte_atomic64_t_cmpset
---
.../common/include/arch/x86/rte_atomic.h | 24 +++++++
.../common/include/arch/x86/rte_atomic_32.h | 12 ++++
.../common/include/arch/x86/rte_atomic_64.h | 12 ++++
lib/librte_eal/common/include/generic/rte_atomic.h | 78 ++++++++++++++++++++++
4 files changed, 126 insertions(+)
diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic.h
b/lib/librte_eal/common/include/arch/x86/rte_atomic.h
index 36cfabc38..55bfc3903 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_atomic.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic.h
@@ -60,6 +60,18 @@ rte_atomic16_cmpset(volatile uint16_t *dst, uint16_t exp,
uint16_t src)
return res;
}
+static inline uint16_t
+rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val)
+{
+ asm volatile(
+ MPLOCKED
+ "xchgw %0, %1;"
+ : "=r" (val), "=m" (*dst)
+ : "0" (val), "m" (*dst)
+ : "memory"); /* no-clobber list */
+ return val;
+}
+
static inline int rte_atomic16_test_and_set(rte_atomic16_t *v)
{
return rte_atomic16_cmpset((volatile uint16_t *)&v->cnt, 0, 1);
@@ -134,6 +146,18 @@ rte_atomic32_cmpset(volatile uint32_t *dst, uint32_t exp,
uint32_t src)
return res;
}
+static inline uint32_t
+rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val)
+{
+ asm volatile(
+ MPLOCKED
+ "xchgl %0, %1;"
+ : "=r" (val), "=m" (*dst)
+ : "0" (val), "m" (*dst)
+ : "memory"); /* no-clobber list */
+ return val;
+}
+
static inline int rte_atomic32_test_and_set(rte_atomic32_t *v)
{
return rte_atomic32_cmpset((volatile uint32_t *)&v->cnt, 0, 1);
diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
b/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
index fb3abf187..8d711b6f6 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_32.h
@@ -98,6 +98,18 @@ rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp,
uint64_t src)
return res;
}
+static inline uint64_t
+rte_atomic64_exchange(volatile uint64_t *dest, uint64_t val)
+{
+ uint64_t old;
+
+ do {
+ old = *dest;
+ } while (rte_atomic64_cmpset(dest, old, val));
+
+ return old;
+}
+
static inline void
rte_atomic64_init(rte_atomic64_t *v)
{
diff --git a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
index 1a53a766b..fd2ec9c53 100644
--- a/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
+++ b/lib/librte_eal/common/include/arch/x86/rte_atomic_64.h
@@ -71,6 +71,18 @@ rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp,
uint64_t src)
return res;
}
+static inline uint64_t
+rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val)
+{
+ asm volatile(
+ MPLOCKED
+ "xchgq %0, %1;"
+ : "=r" (val), "=m" (*dst)
+ : "0" (val), "m" (*dst)
+ : "memory"); /* no-clobber list */
+ return val;
+}
+
static inline void
rte_atomic64_init(rte_atomic64_t *v)
{
diff --git a/lib/librte_eal/common/include/generic/rte_atomic.h
b/lib/librte_eal/common/include/generic/rte_atomic.h
index 3ba7245a3..d3348343c 100644
--- a/lib/librte_eal/common/include/generic/rte_atomic.h
+++ b/lib/librte_eal/common/include/generic/rte_atomic.h
@@ -139,6 +139,32 @@ rte_atomic16_cmpset(volatile uint16_t *dst, uint16_t exp,
uint16_t src)
}
#endif
+/**
+ * Atomic exchange.
+ *
+ * (atomic) equivalent to:
+ * ret = *dst
+ * *dst = val;
+ * return ret;
+ *
+ * @param dst
+ * The destination location into which the value will be written.
+ * @param val
+ * The new value.
+ * @return
+ * The original value at that location
+ */
+static inline uint16_t
+rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline uint16_t
+rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val)
+{
+ return __atomic_exchange_2(dst, val, __ATOMIC_SEQ_CST);
+}
+#endif
+
/**
* The atomic counter structure.
*/
@@ -392,6 +418,32 @@ rte_atomic32_cmpset(volatile uint32_t *dst, uint32_t exp,
uint32_t src)
}
#endif
+/**
+ * Atomic exchange.
+ *
+ * (atomic) equivalent to:
+ * ret = *dst
+ * *dst = val;
+ * return ret;
+ *
+ * @param dst
+ * The destination location into which the value will be written.
+ * @param val
+ * The new value.
+ * @return
+ * The original value at that location
+ */
+static inline uint32_t
+rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline uint32_t
+rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val)
+{
+ return __atomic_exchange_4(dst, val, __ATOMIC_SEQ_CST);
+}
+#endif
+
/**
* The atomic counter structure.
*/
@@ -644,6 +696,32 @@ rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp,
uint64_t src)
}
#endif
+/**
+ * Atomic exchange.
+ *
+ * (atomic) equivalent to:
+ * ret = *dst
+ * *dst = val;
+ * return ret;
+ *
+ * @param dst
+ * The destination location into which the value will be written.
+ * @param val
+ * The new value.
+ * @return
+ * The original value at that location
+ */
+static inline uint64_t
+rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val);
+
+#ifdef RTE_FORCE_INTRINSICS
+static inline uint64_t
+rte_atomic64_exchange(volatile uint64_t *dst, uint64_t val)
+{
+ return __atomic_exchange_4(dst, val, __ATOMIC_SEQ_CST);
+}
+#endif
+
/**
* The atomic counter structure.
*/
--
2.14.3
