[v6,1/4] eal: add new definitions for wait scheme

Message ID 20211027081018.653746-2-feifei.wang2@arm.com (mailing list archive)
State Superseded, archived
Delegated to: David Marchand
Headers
Series add new definitions for wait scheme |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Feifei Wang Oct. 27, 2021, 8:10 a.m. UTC
  Introduce macros as generic interface for address monitoring.
For different size, encapsulate '__LOAD_EXC_16', '__LOAD_EXC_32'
and '__LOAD_EXC_64' into a new macro '__LOAD_EXC'.

Furthermore, to prevent compilation warning in arm:
----------------------------------------------
'warning: implicit declaration of function ...'
----------------------------------------------
Delete 'undef' constructions for '__LOAD_EXC_xx', '__SEVL' and '__WFE'.

This is because original macros are undefine at the end of the file.
If new macro 'rte_wait_event' calls them in other files, they will be
seen as 'not defined'.

Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 lib/eal/arm/include/rte_pause_64.h  | 136 ++++++++++++++++------------
 lib/eal/include/generic/rte_pause.h |  28 ++++++
 2 files changed, 107 insertions(+), 57 deletions(-)
  

Patch

diff --git a/lib/eal/arm/include/rte_pause_64.h b/lib/eal/arm/include/rte_pause_64.h
index e87d10b8cc..87df224ac1 100644
--- a/lib/eal/arm/include/rte_pause_64.h
+++ b/lib/eal/arm/include/rte_pause_64.h
@@ -31,20 +31,12 @@  static inline void rte_pause(void)
 /* Put processor into low power WFE(Wait For Event) state. */
 #define __WFE() { asm volatile("wfe" : : : "memory"); }
 
-static __rte_always_inline void
-rte_wait_until_equal_16(volatile uint16_t *addr, uint16_t expected,
-		int memorder)
-{
-	uint16_t value;
-
-	assert(memorder == __ATOMIC_ACQUIRE || memorder == __ATOMIC_RELAXED);
-
-	/*
-	 * Atomic exclusive load from addr, it returns the 16-bit content of
-	 * *addr while making it 'monitored',when it is written by someone
-	 * else, the 'monitored' state is cleared and a event is generated
-	 * implicitly to exit WFE.
-	 */
+/*
+ * Atomic exclusive load from addr, it returns the 16-bit content of
+ * *addr while making it 'monitored', when it is written by someone
+ * else, the 'monitored' state is cleared and an event is generated
+ * implicitly to exit WFE.
+ */
 #define __LOAD_EXC_16(src, dst, memorder) {               \
 	if (memorder == __ATOMIC_RELAXED) {               \
 		asm volatile("ldxrh %w[tmp], [%x[addr]]"  \
@@ -58,6 +50,62 @@  rte_wait_until_equal_16(volatile uint16_t *addr, uint16_t expected,
 			: "memory");                      \
 	} }
 
+/*
+ * Atomic exclusive load from addr, it returns the 32-bit content of
+ * *addr while making it 'monitored', when it is written by someone
+ * else, the 'monitored' state is cleared and an event is generated
+ * implicitly to exit WFE.
+ */
+#define __LOAD_EXC_32(src, dst, memorder) {              \
+	if (memorder == __ATOMIC_RELAXED) {              \
+		asm volatile("ldxr %w[tmp], [%x[addr]]"  \
+			: [tmp] "=&r" (dst)              \
+			: [addr] "r"(src)                \
+			: "memory");                     \
+	} else {                                         \
+		asm volatile("ldaxr %w[tmp], [%x[addr]]" \
+			: [tmp] "=&r" (dst)              \
+			: [addr] "r"(src)                \
+			: "memory");                     \
+	} }
+
+/*
+ * Atomic exclusive load from addr, it returns the 64-bit content of
+ * *addr while making it 'monitored', when it is written by someone
+ * else, the 'monitored' state is cleared and an event is generated
+ * implicitly to exit WFE.
+ */
+#define __LOAD_EXC_64(src, dst, memorder) {              \
+	if (memorder == __ATOMIC_RELAXED) {              \
+		asm volatile("ldxr %x[tmp], [%x[addr]]"  \
+			: [tmp] "=&r" (dst)              \
+			: [addr] "r"(src)                \
+			: "memory");                     \
+	} else {                                         \
+		asm volatile("ldaxr %x[tmp], [%x[addr]]" \
+			: [tmp] "=&r" (dst)              \
+			: [addr] "r"(src)                \
+			: "memory");                     \
+	} }
+
+#define __LOAD_EXC(src, dst, memorder, size) {          \
+	assert(size == 16 || size == 32 || size == 64); \
+	if (size == 16)                                 \
+		__LOAD_EXC_16(src, dst, memorder)       \
+	else if (size == 32)                            \
+		__LOAD_EXC_32(src, dst, memorder)       \
+	else if (size == 64)                            \
+		__LOAD_EXC_64(src, dst, memorder)       \
+}
+
+static __rte_always_inline void
+rte_wait_until_equal_16(volatile uint16_t *addr, uint16_t expected,
+		int memorder)
+{
+	uint16_t value;
+
+	assert(memorder == __ATOMIC_ACQUIRE || memorder == __ATOMIC_RELAXED);
+
 	__LOAD_EXC_16(addr, value, memorder)
 	if (value != expected) {
 		__SEVL()
@@ -66,7 +114,6 @@  rte_wait_until_equal_16(volatile uint16_t *addr, uint16_t expected,
 			__LOAD_EXC_16(addr, value, memorder)
 		} while (value != expected);
 	}
-#undef __LOAD_EXC_16
 }
 
 static __rte_always_inline void
@@ -77,25 +124,6 @@  rte_wait_until_equal_32(volatile uint32_t *addr, uint32_t expected,
 
 	assert(memorder == __ATOMIC_ACQUIRE || memorder == __ATOMIC_RELAXED);
 
-	/*
-	 * Atomic exclusive load from addr, it returns the 32-bit content of
-	 * *addr while making it 'monitored',when it is written by someone
-	 * else, the 'monitored' state is cleared and a event is generated
-	 * implicitly to exit WFE.
-	 */
-#define __LOAD_EXC_32(src, dst, memorder) {              \
-	if (memorder == __ATOMIC_RELAXED) {              \
-		asm volatile("ldxr %w[tmp], [%x[addr]]"  \
-			: [tmp] "=&r" (dst)              \
-			: [addr] "r"(src)                \
-			: "memory");                     \
-	} else {                                         \
-		asm volatile("ldaxr %w[tmp], [%x[addr]]" \
-			: [tmp] "=&r" (dst)              \
-			: [addr] "r"(src)                \
-			: "memory");                     \
-	} }
-
 	__LOAD_EXC_32(addr, value, memorder)
 	if (value != expected) {
 		__SEVL()
@@ -104,7 +132,6 @@  rte_wait_until_equal_32(volatile uint32_t *addr, uint32_t expected,
 			__LOAD_EXC_32(addr, value, memorder)
 		} while (value != expected);
 	}
-#undef __LOAD_EXC_32
 }
 
 static __rte_always_inline void
@@ -115,25 +142,6 @@  rte_wait_until_equal_64(volatile uint64_t *addr, uint64_t expected,
 
 	assert(memorder == __ATOMIC_ACQUIRE || memorder == __ATOMIC_RELAXED);
 
-	/*
-	 * Atomic exclusive load from addr, it returns the 64-bit content of
-	 * *addr while making it 'monitored',when it is written by someone
-	 * else, the 'monitored' state is cleared and a event is generated
-	 * implicitly to exit WFE.
-	 */
-#define __LOAD_EXC_64(src, dst, memorder) {              \
-	if (memorder == __ATOMIC_RELAXED) {              \
-		asm volatile("ldxr %x[tmp], [%x[addr]]"  \
-			: [tmp] "=&r" (dst)              \
-			: [addr] "r"(src)                \
-			: "memory");                     \
-	} else {                                         \
-		asm volatile("ldaxr %x[tmp], [%x[addr]]" \
-			: [tmp] "=&r" (dst)              \
-			: [addr] "r"(src)                \
-			: "memory");                     \
-	} }
-
 	__LOAD_EXC_64(addr, value, memorder)
 	if (value != expected) {
 		__SEVL()
@@ -143,10 +151,24 @@  rte_wait_until_equal_64(volatile uint64_t *addr, uint64_t expected,
 		} while (value != expected);
 	}
 }
-#undef __LOAD_EXC_64
 
-#undef __SEVL
-#undef __WFE
+#define rte_wait_event(addr, mask, cond, expected, memorder)      \
+do {                                                              \
+	RTE_BUILD_BUG_ON(!__builtin_constant_p(memorder));        \
+	RTE_BUILD_BUG_ON(memorder != __ATOMIC_ACQUIRE &&          \
+				memorder != __ATOMIC_RELAXED);    \
+	uint32_t size = sizeof(*(addr)) << 3;                     \
+	typeof(*(addr)) expected_value = (expected);              \
+	typeof(*(addr)) value = 0;                                \
+	__LOAD_EXC((addr), value, memorder, size)                 \
+	if ((value & (mask)) cond expected_value) {               \
+		__SEVL()                                          \
+		do {                                              \
+			__WFE()                                   \
+			__LOAD_EXC((addr), value, memorder, size) \
+		} while ((value & (mask)) cond expected_value);   \
+	}                                                         \
+} while (0)
 
 #endif
 
diff --git a/lib/eal/include/generic/rte_pause.h b/lib/eal/include/generic/rte_pause.h
index 668ee4a184..d0c5b5a415 100644
--- a/lib/eal/include/generic/rte_pause.h
+++ b/lib/eal/include/generic/rte_pause.h
@@ -111,6 +111,34 @@  rte_wait_until_equal_64(volatile uint64_t *addr, uint64_t expected,
 	while (__atomic_load_n(addr, memorder) != expected)
 		rte_pause();
 }
+
+/*
+ * Wait until *addr breaks the condition, with a relaxed memory
+ * ordering model meaning the loads around this API can be reordered.
+ *
+ * @param addr
+ *  A pointer to the memory location.
+ * @param mask
+ *  A mask of value bits in interest.
+ * @param cond
+ *  A symbol representing the condition.
+ * @param expected
+ *  An expected value to be in the memory location.
+ * @param memorder
+ *  Two different memory orders that can be specified:
+ *  __ATOMIC_ACQUIRE and __ATOMIC_RELAXED. These map to
+ *  C++11 memory orders with the same names, see the C++11 standard or
+ *  the GCC wiki on atomic synchronization for detailed definition.
+ */
+#define rte_wait_event(addr, mask, cond, expected, memorder)                       \
+do {                                                                               \
+	RTE_BUILD_BUG_ON(!__builtin_constant_p(memorder));                         \
+	RTE_BUILD_BUG_ON(memorder != __ATOMIC_ACQUIRE &&                           \
+				memorder != __ATOMIC_RELAXED);                     \
+	typeof(*(addr)) expected_value = (expected);                               \
+	while ((__atomic_load_n((addr), (memorder)) & (mask)) cond expected_value) \
+		rte_pause();                                                       \
+} while (0)
 #endif
 
 #endif /* _RTE_PAUSE_H_ */