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From: Gage Eads <gage.eads@intel.com>
To: dev@dpdk.org
Cc: olivier.matz@6wind.com, arybchenko@solarflare.com,
	bruce.richardson@intel.com, konstantin.ananyev@intel.com,
	gavin.hu@arm.com, Honnappa.Nagarahalli@arm.com, nd@arm.com,
	chaozhu@linux.vnet.ibm.com, jerinj@marvell.com,
	hemant.agrawal@nxp.com, thomas@monjalon.net
Subject: [dpdk-dev] [PATCH v4 1/1] eal: add 128-bit compare exchange (x86-64 only)
Date: Wed,  3 Apr 2019 12:34:38 -0500	[thread overview]
Message-ID: <20190403173438.23691-2-gage.eads@intel.com> (raw)
Message-ID: <20190403173438.MI5MqjVTQ-KaDrBrHFauNUcZSz-b4tl2PhJnXbprcQo@z> (raw)
In-Reply-To: <20190403173438.23691-1-gage.eads@intel.com>

This operation can be used for non-blocking algorithms, such as a
non-blocking stack or ring.

Signed-off-by: Gage Eads <gage.eads@intel.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
---
 .../common/include/arch/x86/rte_atomic_64.h        | 81 ++++++++++++++++++++++
 1 file changed, 81 insertions(+)

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 fd2ec9c53..49bce32c7 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
@@ -34,6 +34,7 @@
 /*
  * Inspired from FreeBSD src/sys/amd64/include/atomic.h
  * Copyright (c) 1998 Doug Rabson
+ * Copyright (c) 2019 Intel Corporation
  * All rights reserved.
  */
 
@@ -46,6 +47,7 @@
 
 #include <stdint.h>
 #include <rte_common.h>
+#include <rte_compat.h>
 #include <rte_atomic.h>
 
 /*------------------------- 64 bit atomic operations -------------------------*/
@@ -208,4 +210,83 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v)
 }
 #endif
 
+/*------------------------ 128 bit atomic operations -------------------------*/
+
+/**
+ * 128-bit integer structure.
+ */
+RTE_STD_C11
+typedef struct {
+	RTE_STD_C11
+	union {
+		uint64_t val[2];
+		__int128 int128;
+	};
+} __rte_aligned(16) rte_int128_t;
+
+/**
+ * An atomic compare and set function used by the mutex functions.
+ * (Atomically) Equivalent to:
+ *   if (*dst == *exp)
+ *     *dst = *src
+ *   else
+ *     *exp = *dst
+ *
+ * @note The success and failure arguments must be one of the __ATOMIC_* values
+ * defined in the C++11 standard. For details on their behavior, refer to the
+ * standard.
+ *
+ * @param dst
+ *   The destination into which the value will be written.
+ * @param exp
+ *   Pointer to the expected value. If the operation fails, this memory is
+ *   updated with the actual value.
+ * @param src
+ *   Pointer to the new value.
+ * @param weak
+ *   A value of true allows the comparison to spuriously fail and allows the
+ *   'exp' update to occur non-atomically (i.e. a torn read may occur).
+ *   Implementations may ignore this argument and only implement the strong
+ *   variant.
+ * @param success
+ *   If successful, the operation's memory behavior conforms to this (or a
+ *   stronger) model.
+ * @param failure
+ *   If unsuccessful, the operation's memory behavior conforms to this (or a
+ *   stronger) model. This argument cannot be __ATOMIC_RELEASE,
+ *   __ATOMIC_ACQ_REL, or a stronger model than success.
+ * @return
+ *   Non-zero on success; 0 on failure.
+ */
+static inline int __rte_experimental
+rte_atomic128_cmp_exchange(rte_int128_t *dst,
+			   rte_int128_t *exp,
+			   const rte_int128_t *src,
+			   unsigned int weak,
+			   int success,
+			   int failure)
+{
+	RTE_SET_USED(weak);
+	RTE_SET_USED(success);
+	RTE_SET_USED(failure);
+	uint8_t res;
+
+	asm volatile (
+		      MPLOCKED
+		      "cmpxchg16b %[dst];"
+		      " sete %[res]"
+		      : [dst] "=m" (dst->val[0]),
+			"=a" (exp->val[0]),
+			"=d" (exp->val[1]),
+			[res] "=r" (res)
+		      : "b" (src->val[0]),
+			"c" (src->val[1]),
+			"a" (exp->val[0]),
+			"d" (exp->val[1]),
+			"m" (dst->val[0])
+		      : "memory");
+
+	return res;
+}
+
 #endif /* _RTE_ATOMIC_X86_64_H_ */
-- 
2.13.6


  parent reply	other threads:[~2019-04-03 17:35 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-28 17:29 [dpdk-dev] [PATCH 0/1] Add 128-bit compare and set Gage Eads
2019-01-28 17:29 ` [dpdk-dev] [PATCH 1/1] eal: add 128-bit cmpset (x86-64 only) Gage Eads
2019-01-28 23:01   ` Ola Liljedahl
2019-02-01 17:06     ` Eads, Gage
2019-02-01 19:01       ` Ola Liljedahl
2019-02-01 19:28         ` Eads, Gage
2019-02-01 19:43           ` Ola Liljedahl
2019-02-01 21:05             ` Eads, Gage
2019-02-01 23:11               ` Ola Liljedahl
2019-02-04 18:33       ` Honnappa Nagarahalli
2019-01-31  5:48   ` Honnappa Nagarahalli
2019-02-01 17:11     ` Eads, Gage
2019-02-22 15:46 ` [dpdk-dev] [PATCH v2 0/1] Add 128-bit compare and set Gage Eads
2019-02-22 15:46   ` [dpdk-dev] [PATCH v2 1/1] eal: add 128-bit cmpxchg (x86-64 only) Gage Eads
2019-03-04 20:19     ` Honnappa Nagarahalli
2019-03-04 20:47       ` Eads, Gage
2019-03-04 20:51   ` [dpdk-dev] [PATCH v3 0/1] Add 128-bit compare and set Gage Eads
2019-03-04 20:51     ` [dpdk-dev] [PATCH v3 1/1] eal: add 128-bit compare exchange (x86-64 only) Gage Eads
2019-03-27 23:12       ` Thomas Monjalon
2019-03-27 23:12         ` Thomas Monjalon
2019-03-28 16:22         ` Eads, Gage
2019-03-28 16:22           ` Eads, Gage
2019-04-03 17:34     ` [dpdk-dev] [PATCH v4 0/1] Add 128-bit compare and set Gage Eads
2019-04-03 17:34       ` Gage Eads
2019-04-03 17:34       ` Gage Eads [this message]
2019-04-03 17:34         ` [dpdk-dev] [PATCH v4 1/1] eal: add 128-bit compare exchange (x86-64 only) Gage Eads
2019-04-03 19:04         ` Thomas Monjalon
2019-04-03 19:04           ` Thomas Monjalon
2019-04-03 19:21           ` Eads, Gage
2019-04-03 19:21             ` Eads, Gage
2019-04-03 19:27             ` Thomas Monjalon
2019-04-03 19:27               ` Thomas Monjalon
2019-04-03 19:35 ` [dpdk-dev] [PATCH v5] eal/x86: add 128-bit atomic compare exchange Thomas Monjalon
2019-04-03 19:35   ` Thomas Monjalon
2019-04-03 19:44   ` [dpdk-dev] [PATCH v6] " Gage Eads
2019-04-03 19:44     ` Gage Eads
2019-04-03 20:01     ` Thomas Monjalon
2019-04-03 20:01       ` Thomas Monjalon
2019-04-04 11:47     ` Ferruh Yigit
2019-04-04 11:47       ` Ferruh Yigit
2019-04-04 12:08       ` Thomas Monjalon
2019-04-04 12:08         ` Thomas Monjalon
2019-04-04 12:12         ` Thomas Monjalon
2019-04-04 12:12           ` Thomas Monjalon
2019-04-04 12:14           ` Eads, Gage
2019-04-04 12:14             ` Eads, Gage
2019-04-04 12:18             ` Thomas Monjalon
2019-04-04 12:18               ` Thomas Monjalon
2019-04-04 12:22               ` Eads, Gage
2019-04-04 12:22                 ` Eads, Gage
2019-04-04 12:24               ` Eads, Gage
2019-04-04 12:24                 ` Eads, Gage
2019-04-04 12:52               ` Ferruh Yigit
2019-04-04 12:52                 ` Ferruh Yigit

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