From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 2924EA046B for ; Sun, 23 Jun 2019 04:41:34 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 1F6EA1C125; Sun, 23 Jun 2019 04:41:33 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id B72251BEF1 for ; Sun, 23 Jun 2019 04:41:31 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E9247360; Sat, 22 Jun 2019 19:41:30 -0700 (PDT) Received: from phil-VirtualBox.shanghai.arm.com (unknown [10.171.20.36]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1DBCD3F575; Sat, 22 Jun 2019 19:41:28 -0700 (PDT) From: Phil Yang To: dev@dpdk.org Cc: thomas@monjalon.net, jerinj@marvell.com, hemant.agrawal@nxp.com, Honnappa.Nagarahalli@arm.com, gavin.hu@arm.com, nd@arm.com, gage.eads@intel.com Date: Sun, 23 Jun 2019 10:41:09 +0800 Message-Id: <1561257671-10316-1-git-send-email-phil.yang@arm.com> X-Mailer: git-send-email 2.7.4 Subject: [dpdk-dev] [PATCH v1 1/3] eal/arm64: add 128-bit atomic compare exchange X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Add 128-bit atomic compare exchange on aarch64. Signed-off-by: Phil Yang Tested-by: Honnappa Nagarahalli Reviewed-by: Honnappa Nagarahalli --- This patch depends on http://patchwork.dpdk.org/patch/54840/ v2: eal/stack: fix 'pointer-sign' warning .../common/include/arch/arm/rte_atomic_64.h | 184 +++++++++++++++++++++ .../common/include/arch/x86/rte_atomic_64.h | 12 -- lib/librte_eal/common/include/generic/rte_atomic.h | 15 +- 3 files changed, 198 insertions(+), 13 deletions(-) diff --git a/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h b/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h index 97060e4..4ef900c 100644 --- a/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h +++ b/lib/librte_eal/common/include/arch/arm/rte_atomic_64.h @@ -1,5 +1,6 @@ /* SPDX-License-Identifier: BSD-3-Clause * Copyright(c) 2015 Cavium, Inc + * Copyright(c) 2019 Arm Limited */ #ifndef _RTE_ATOMIC_ARM64_H_ @@ -14,6 +15,9 @@ extern "C" { #endif #include "generic/rte_atomic.h" +#include +#include +#include #define dsb(opt) asm volatile("dsb " #opt : : : "memory") #define dmb(opt) asm volatile("dmb " #opt : : : "memory") @@ -40,6 +44,186 @@ extern "C" { #define rte_cio_rmb() dmb(oshld) +/*----------------------- 128 bit atomic operations -------------------------*/ + +#define RTE_HAS_ACQ(mo) ((mo) != __ATOMIC_RELAXED && (mo) != __ATOMIC_RELEASE) +#define RTE_HAS_RLS(mo) ((mo) == __ATOMIC_RELEASE || \ + (mo) == __ATOMIC_ACQ_REL || \ + (mo) == __ATOMIC_SEQ_CST) + +#define RTE_MO_LOAD(mo) (RTE_HAS_ACQ((mo)) \ + ? __ATOMIC_ACQUIRE : __ATOMIC_RELAXED) +#define RTE_MO_STORE(mo) (RTE_HAS_RLS((mo)) \ + ? __ATOMIC_RELEASE : __ATOMIC_RELAXED) + +#ifdef __ARM_FEATURE_ATOMICS +static inline rte_int128_t +__rte_casp(rte_int128_t *dst, rte_int128_t old, rte_int128_t updated, int mo) +{ + + /* caspX instructions register pair must start from even-numbered + * register at operand 1. + * So, specify registers for local variables here. + */ + register uint64_t x0 __asm ("x0") = (uint64_t)old.val[0]; + register uint64_t x1 __asm ("x1") = (uint64_t)old.val[1]; + register uint64_t x2 __asm ("x2") = (uint64_t)updated.val[0]; + register uint64_t x3 __asm ("x3") = (uint64_t)updated.val[1]; + + if (mo == __ATOMIC_RELAXED) { + asm volatile( + "casp %[old0], %[old1], %[upd0], %[upd1], [%[dst]]" + : [old0] "+r" (x0), + [old1] "+r" (x1) + : [upd0] "r" (x2), + [upd1] "r" (x3), + [dst] "r" (dst) + : "memory"); + } else if (mo == __ATOMIC_ACQUIRE) { + asm volatile( + "caspa %[old0], %[old1], %[upd0], %[upd1], [%[dst]]" + : [old0] "+r" (x0), + [old1] "+r" (x1) + : [upd0] "r" (x2), + [upd1] "r" (x3), + [dst] "r" (dst) + : "memory"); + } else if (mo == __ATOMIC_ACQ_REL) { + asm volatile( + "caspal %[old0], %[old1], %[upd0], %[upd1], [%[dst]]" + : [old0] "+r" (x0), + [old1] "+r" (x1) + : [upd0] "r" (x2), + [upd1] "r" (x3), + [dst] "r" (dst) + : "memory"); + } else if (mo == __ATOMIC_RELEASE) { + asm volatile( + "caspl %[old0], %[old1], %[upd0], %[upd1], [%[dst]]" + : [old0] "+r" (x0), + [old1] "+r" (x1) + : [upd0] "r" (x2), + [upd1] "r" (x3), + [dst] "r" (dst) + : "memory"); + } else { + rte_panic("Invalid memory order\n"); + } + + old.val[0] = x0; + old.val[1] = x1; + + return old; +} +#else +static inline rte_int128_t +__rte_ldx128(const rte_int128_t *src, int mo) +{ + rte_int128_t ret; + if (mo == __ATOMIC_ACQUIRE) + asm volatile( + "ldaxp %0, %1, %2" + : "=&r" (ret.val[0]), + "=&r" (ret.val[1]) + : "Q" (src->val[0]) + : "memory"); + else if (mo == __ATOMIC_RELAXED) + asm volatile( + "ldxp %0, %1, %2" + : "=&r" (ret.val[0]), + "=&r" (ret.val[1]) + : "Q" (src->val[0]) + : "memory"); + else + rte_panic("Invalid memory order\n"); + + return ret; +} + +static inline uint32_t +__rte_stx128(rte_int128_t *dst, const rte_int128_t src, int mo) +{ + uint32_t ret; + if (mo == __ATOMIC_RELEASE) + asm volatile( + "stlxp %w0, %1, %2, %3" + : "=&r" (ret) + : "r" (src.val[0]), + "r" (src.val[1]), + "Q" (dst->val[0]) + : "memory"); + else if (mo == __ATOMIC_RELAXED) + asm volatile( + "stxp %w0, %1, %2, %3" + : "=&r" (ret) + : "r" (src.val[0]), + "r" (src.val[1]), + "Q" (dst->val[0]) + : "memory"); + else + rte_panic("Invalid memory order\n"); + + /* Return 0 on success, 1 on failure */ + return ret; +} +#endif + +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) +{ + // Always do strong CAS + RTE_SET_USED(weak); + /* Ignore memory ordering for failure, memory order for + * success must be stronger or equal + */ + RTE_SET_USED(failure); + +#ifdef __ARM_FEATURE_ATOMICS + rte_int128_t expected = *exp; + rte_int128_t desired = *src; + rte_int128_t old; + + old = __rte_casp(dst, expected, desired, success); +#else + int ldx_mo = RTE_MO_LOAD(success); + int stx_mo = RTE_MO_STORE(success); + uint32_t ret = 1; + register rte_int128_t expected = *exp; + register rte_int128_t desired = *src; + register rte_int128_t old; + + /* ldx128 can not guarantee atomic, + * Must write back src or old to verify atomicity of ldx128; + */ + do { + old = __rte_ldx128(dst, ldx_mo); + if (likely(old.int128 == expected.int128)) + ret = __rte_stx128(dst, desired, stx_mo); + else + /* In the failure case (since 'weak' is ignored and only + * weak == 0 is implemented), expected should contain the + * atomically read value of dst. This means, 'old' needs + * to be stored back to ensure it was read atomically. + */ + ret = __rte_stx128(dst, old, stx_mo); + } while (unlikely(ret)); +#endif + + /* Unconditionally updating expected removes + * an 'if' statement. + * expected should already be in register if + * not in the cache. + */ + *exp = old; + + return (old.int128 == expected.int128); +} + #ifdef __cplusplus } #endif 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 6232c57..23cf48f 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 @@ -212,18 +212,6 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v) /*------------------------ 128 bit atomic operations -------------------------*/ -/** - * 128-bit integer structure. - */ -RTE_STD_C11 -typedef struct { - RTE_STD_C11 - union { - uint64_t val[2]; - __extension__ __int128 int128; - }; -} __rte_aligned(16) rte_int128_t; - static inline int __rte_experimental rte_atomic128_cmp_exchange(rte_int128_t *dst, rte_int128_t *exp, diff --git a/lib/librte_eal/common/include/generic/rte_atomic.h b/lib/librte_eal/common/include/generic/rte_atomic.h index 9958543..7dd1aa4 100644 --- a/lib/librte_eal/common/include/generic/rte_atomic.h +++ b/lib/librte_eal/common/include/generic/rte_atomic.h @@ -1081,6 +1081,18 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v) /*------------------------ 128 bit atomic operations -------------------------*/ +/** + * 128-bit integer structure. + */ +RTE_STD_C11 +typedef struct { + RTE_STD_C11 + union { + uint64_t val[2]; + __extension__ __int128 int128; + }; +} __rte_aligned(16) rte_int128_t; + #ifdef __DOXYGEN__ /** @@ -1093,7 +1105,8 @@ static inline void rte_atomic64_clear(rte_atomic64_t *v) * *exp = *dst * @endcode * - * @note This function is currently only available for the x86-64 platform. + * @note This function is currently available for the x86-64 and aarch64 + * platforms. * * @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 -- 2.7.4