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[84.217.193.77]) by mx.google.com with ESMTPSA id y3sm434075lad.7.2014.11.27.07.13.07 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 27 Nov 2014 07:13:07 -0800 (PST) From: Ola Liljedahl To: lng-odp@lists.linaro.org Date: Thu, 27 Nov 2014 16:12:57 +0100 Message-Id: <1417101181-13500-2-git-send-email-ola.liljedahl@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1417101181-13500-1-git-send-email-ola.liljedahl@linaro.org> References: <1417101181-13500-1-git-send-email-ola.liljedahl@linaro.org> X-Topics: patch Subject: [lng-odp] [PATCHv2 1/5] linux-generic: odp_atomic_internal.h: C11-style 32/64-bit/pointer/flag atomics X-BeenThere: lng-odp@lists.linaro.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: , List-Help: , List-Subscribe: , MIME-Version: 1.0 Errors-To: lng-odp-bounces@lists.linaro.org Sender: lng-odp-bounces@lists.linaro.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: ola.liljedahl@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.47 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 Signed-off-by: Ola Liljedahl Reviewed-by: Bill Fischofer --- (This document/code contribution attached is provided under the terms of agreement LES-LTM-21309) Operations (including exchange and compare-and-exchange) with specified C11-based memory models on odp_atomic_u32_t and odp_atomic_u64_t. odp_atomic_ptr_t definition and operations (init, load, store, exchange). odp_atomic_flag_t definitions and operations (init, load, tas, clear). All internal type and function names are now prefixed with "_" (underscore). .../linux-generic/include/odp_atomic_internal.h | 605 +++++++++++++++++++++ 1 file changed, 605 insertions(+) create mode 100644 platform/linux-generic/include/odp_atomic_internal.h diff --git a/platform/linux-generic/include/odp_atomic_internal.h b/platform/linux-generic/include/odp_atomic_internal.h new file mode 100644 index 0000000..e0b842b --- /dev/null +++ b/platform/linux-generic/include/odp_atomic_internal.h @@ -0,0 +1,605 @@ +/* Copyright (c) 2014, Linaro Limited + * All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +/** + * @file + * + * ODP atomic types and operations, semantically a subset of C11 atomics. + * Reuse the 32-bit and 64-bit type definitions from odp_atomic.h. Introduces + * new atomic pointer and flag types. + * Atomic functions must be used to operate on atomic variables! + */ + +#ifndef ODP_ATOMIC_INTERNAL_H_ +#define ODP_ATOMIC_INTERNAL_H_ + +#include +#include +#include +#include +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/** @addtogroup odp_synchronizers + * Atomic operations. + * @{ + */ + +/** + * Pointer atomic type + */ +typedef struct { + void *v; /**< Actual storage for the atomic variable */ +} _odp_atomic_ptr_t +ODP_ALIGNED(sizeof(void *)); /* Enforce alignement! */ + +/** + * Atomic flag (boolean) type + * @Note this is not the same as a plain boolean type. + * _odp_atomic_flag_t is guaranteed to be able to operate on atomically. + */ +typedef char _odp_atomic_flag_t; + +/** + * Memory consistency models supported by ODP. + */ +typedef enum { +/** Relaxed memory model, no ordering of other accesses enforced. + * Atomic operations with relaxed memory model cannot be used for + * synchronization */ + _ODP_MEMMODEL_RLX = __ATOMIC_RELAXED, +/** Acquire memory model, synchronize with release stores from another + * thread (later accesses cannot move before acquire operation). + * Use acquire and release memory models for Release Consistency */ + _ODP_MEMMODEL_ACQ = __ATOMIC_ACQUIRE, +/** Release memory model, synchronize with acquire loads from another + * thread (earlier accesses cannot move after release operation). + * Use acquire and release memory models for Release Consistency */ + _ODP_MEMMODEL_RLS = __ATOMIC_RELEASE, +/** Acquire&release memory model, synchronize with acquire loads and release + * stores in another (one other) thread */ + _ODP_MEMMODEL_ACQ_RLS = __ATOMIC_ACQ_REL, +/** Sequential consistent memory model, synchronize with acquire loads and + * release stores in all threads */ + _ODP_MEMMODEL_SC = __ATOMIC_SEQ_CST +} _odp_memmodel_t; + +/** + * Insert a full memory barrier (fence) in the compiler and instruction + * sequence. + */ +#define _ODP_FULL_BARRIER() __atomic_thread_fence(__ATOMIC_SEQ_CST) + +/***************************************************************************** + * Operations on 32-bit atomics + * _odp_atomic_u32_load_mm - return current value + * _odp_atomic_u32_store_mm - no return value + * _odp_atomic_u32_xchg_mm - return old value + * _odp_atomic_u32_cmp_xchg_strong_mm - return bool + * _odp_atomic_u32_fetch_add_mm - return old value + * _odp_atomic_u32_add_mm - no return value + * _odp_atomic_u32_fetch_sub_mm - return old value + * _odp_atomic_u32_sub_mm - no return value + *****************************************************************************/ + +/** + * Atomic load of 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param mmodel Memory model associated with the load operation + * + * @return Value of the variable + */ +static inline uint32_t _odp_atomic_u32_load_mm(const odp_atomic_u32_t *ptr, + _odp_memmodel_t mmodel) +{ + return __atomic_load_n(&ptr->v, mmodel); +} + +/** + * Atomic store to 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param val Value to store in the atomic variable + * @param mmodel Memory model associated with the store operation + */ +static inline void _odp_atomic_u32_store_mm(odp_atomic_u32_t *ptr, + uint32_t val, + _odp_memmodel_t mmodel) +{ + __atomic_store_n(&ptr->v, val, mmodel); +} + +/** + * Atomic exchange (swap) of 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param val New value to store in the atomic variable + * @param mmodel Memory model associated with the exchange operation + * + * @return Old value of the variable + */ +static inline uint32_t _odp_atomic_u32_xchg_mm(odp_atomic_u32_t *ptr, + uint32_t val, + _odp_memmodel_t mmodel) + +{ + return __atomic_exchange_n(&ptr->v, val, mmodel); +} + +/** + * Atomic compare and exchange (swap) of 32-bit atomic variable + * "Strong" semantics, will not fail spuriously. + * + * @param ptr Pointer to a 32-bit atomic variable + * @param exp_p Pointer to expected value (updated on failure) + * @param val New value to write + * @param succ Memory model associated with a successful compare-and-swap + * operation + * @param fail Memory model associated with a failed compare-and-swap + * operation + * + * @return 1 (true) if exchange successful, 0 (false) if not successful (and + * '*exp_p' updated with current value) + */ +static inline int _odp_atomic_u32_cmp_xchg_strong_mm(odp_atomic_u32_t *ptr, + uint32_t *exp_p, + uint32_t val, + _odp_memmodel_t succ, + _odp_memmodel_t fail) +{ + return __atomic_compare_exchange_n(&ptr->v, exp_p, val, + false/*strong*/, succ, fail); +} + +/** + * Atomic fetch and add of 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param val Value to add to the atomic variable + * @param mmodel Memory model associated with the add operation + * + * @return Value of the atomic variable before the addition + */ +static inline uint32_t _odp_atomic_u32_fetch_add_mm(odp_atomic_u32_t *ptr, + uint32_t val, + _odp_memmodel_t mmodel) +{ + return __atomic_fetch_add(&ptr->v, val, mmodel); +} + +/** + * Atomic add of 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param val Value to add to the atomic variable + * @param mmodel Memory model associated with the add operation + */ +static inline void _odp_atomic_u32_add_mm(odp_atomic_u32_t *ptr, + uint32_t val, + _odp_memmodel_t mmodel) + +{ + (void)__atomic_fetch_add(&ptr->v, val, mmodel); +} + +/** + * Atomic fetch and subtract of 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param val Value to subtract from the atomic variable + * @param mmodel Memory model associated with the subtract operation + * + * @return Value of the atomic variable before the subtraction + */ +static inline uint32_t _odp_atomic_u32_fetch_sub_mm(odp_atomic_u32_t *ptr, + uint32_t val, + _odp_memmodel_t mmodel) +{ + return __atomic_fetch_sub(&ptr->v, val, mmodel); +} + +/** + * Atomic subtract of 32-bit atomic variable + * + * @param ptr Pointer to a 32-bit atomic variable + * @param val Value to subtract from the atomic variable + * @param mmodel Memory model associated with the subtract operation + */ +static inline void _odp_atomic_u32_sub_mm(odp_atomic_u32_t *ptr, + uint32_t val, + _odp_memmodel_t mmodel) + +{ + (void)__atomic_fetch_sub(&ptr->v, val, mmodel); +} + +/***************************************************************************** + * Operations on 64-bit atomics + * _odp_atomic_u64_load_mm - return current value + * _odp_atomic_u64_store_mm - no return value + * _odp_atomic_u64_xchg_mm - return old value + * _odp_atomic_u64_cmp_xchg_strong_mm - return bool + * _odp_atomic_u64_fetch_add_mm - return old value + * _odp_atomic_u64_add_mm - no return value + * _odp_atomic_u64_fetch_sub_mm - return old value + * _odp_atomic_u64_sub_mm - no return value + *****************************************************************************/ + +/* Check if the compiler support lock-less atomic operations on 64-bit types */ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 +/** + * @internal + * Helper macro for lock-based atomic operations on 64-bit integers + * @param ptr Pointer to the 64-bit atomic variable + * @param expr Expression used update the variable. + * @param mm Memory model to use. + * @return The old value of the variable. + */ +#define ATOMIC_OP_MM(ptr, expr, mm) \ +({ \ + uint64_t old_val; \ + /* Loop while lock is already taken, stop when lock becomes clear */ \ + while (__atomic_test_and_set(&(ptr)->lock, \ + (mm) == _ODP_MEMMODELSC ? \ + __ATOMIC_SEQ_CST : __ATOMIC_ACQUIRE)) \ + (void)0; \ + old_val = (ptr)->v; \ + (expr); /* Perform whatever update is desired */ \ + __atomic_clear(&(ptr)->lock, \ + (mm) == _ODP_MEMMODELSC ? \ + __ATOMIC_SEQ_CST : __ATOMIC_RELEASE); \ + old_val; /* Return old value */ \ +}) +#endif + +/** + * Atomic load of 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param mmodel Memory model associated with the load operation + * + * @return Value of the variable + */ +static inline uint64_t _odp_atomic_u64_load_mm(odp_atomic_u64_t *ptr, + _odp_memmodel_t mmodel) +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + return ATOMIC_OP_MM(ptr, (void)0, mmodel); +#else + return __atomic_load_n(&ptr->v, mmodel); +#endif +} + +/** + * Atomic store to 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param val Value to write to the atomic variable + * @param mmodel Memory model associated with the store operation + */ +static inline void _odp_atomic_u64_store_mm(odp_atomic_u64_t *ptr, + uint64_t val, + _odp_memmodel_t mmodel) +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + (void)ATOMIC_OP_MM(ptr, ptr->v = val, mmodel); +#else + __atomic_store_n(&ptr->v, val, mmodel); +#endif +} + +/** + * Atomic exchange (swap) of 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param val New value to write to the atomic variable + * @param mmodel Memory model associated with the exchange operation + * + * @return Old value of variable + */ +static inline uint64_t _odp_atomic_u64_xchg_mm(odp_atomic_u64_t *ptr, + uint64_t val, + _odp_memmodel_t mmodel) + +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + return ATOMIC_OP_MM(ptr, ptr->v = val, mmodel); +#else + return __atomic_exchange_n(&ptr->v, val, mmodel); +#endif +} + +/** + * Atomic compare and exchange (swap) of 64-bit atomic variable + * "Strong" semantics, will not fail spuriously. + * + * @param ptr Pointer to a 64-bit atomic variable + * @param exp_p Pointer to expected value (updated on failure) + * @param val New value to write + * @param succ Memory model associated with a successful compare-and-swap + * operation + * @param fail Memory model associated with a failed compare-and-swap operation + * + * @return 1 (true) if exchange successful, 0 (false) if not successful (and + * '*exp_p' updated with current value) + */ +static inline int _odp_atomic_u64_cmp_xchg_strong_mm(odp_atomic_u64_t *ptr, + uint64_t *exp_p, + uint64_t val, + _odp_memmodel_t succ, + _odp_memmodel_t fail) +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + /* Possibly we are a bit pessimistic with the memory models */ + int success; + /* Loop while lock is already taken, stop when lock becomes clear */ + while (__atomic_test_and_set(&(ptr)->lock, + (succ) == _ODP_MEMMODELSC ? + __ATOMIC_SEQ_CST : __ATOMIC_ACQUIRE)) + (void)0; + if (ptr->v == *exp_p) { + ptr->v = val; + success = 1; + } else { + *exp_p = ptr->v; + success = 0; + succ = fail; + } + __atomic_clear(&(ptr)->lock, + (succ) == _ODP_MEMMODELSC ? + __ATOMIC_SEQ_CST : __ATOMIC_RELEASE); + return success; +#else + return __atomic_compare_exchange_n(&ptr->v, exp_p, val, + false, succ, fail); +#endif +} + +/** + * Atomic fetch and add of 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param val Value to add to the atomic variable + * @param mmodel Memory model associated with the add operation + * + * @return Value of the atomic variable before the addition + */ +static inline uint64_t _odp_atomic_u64_fetch_add_mm(odp_atomic_u64_t *ptr, + uint64_t val, + _odp_memmodel_t mmodel) +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + return ATOMIC_OP_MM(ptr, ptr->v += val, mmodel); +#else + return __atomic_fetch_add(&ptr->v, val, mmodel); +#endif +} + +/** + * Atomic add of 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param val Value to add to the atomic variable + * @param mmodel Memory model associated with the add operation. + */ +static inline void _odp_atomic_u64_add_mm(odp_atomic_u64_t *ptr, + uint64_t val, + _odp_memmodel_t mmodel) + +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + (void)ATOMIC_OP_MM(ptr, ptr->v += val, mmodel); +#else + (void)__atomic_fetch_add(&ptr->v, val, mmodel); +#endif +} + +/** + * Atomic fetch and subtract of 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param val Value to subtract from the atomic variable + * @param mmodel Memory model associated with the subtract operation + * + * @return Value of the atomic variable before the subtraction + */ +static inline uint64_t _odp_atomic_u64_fetch_sub_mm(odp_atomic_u64_t *ptr, + uint64_t val, + _odp_memmodel_t mmodel) +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + return ATOMIC_OP_MM(ptr, ptr->v -= val, mmodel); +#else + return __atomic_fetch_sub(&ptr->v, val, mmodel); +#endif +} + +/** + * Atomic subtract of 64-bit atomic variable + * + * @param ptr Pointer to a 64-bit atomic variable + * @param val Value to subtract from the atomic variable + * @param mmodel Memory model associated with the subtract operation + */ +static inline void _odp_atomic_u64_sub_mm(odp_atomic_u64_t *ptr, + uint64_t val, + _odp_memmodel_t mmodel) + +{ +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 + (void)ATOMIC_OP_MM(ptr, ptr->v -= val, mmodel); +#else + (void)__atomic_fetch_sub(&ptr->v, val, mmodel); +#endif +} + +#if !defined __GCC_ATOMIC_LLONG_LOCK_FREE || __GCC_ATOMIC_LLONG_LOCK_FREE < 2 +#undef ATOMIC_OP_MM +#endif + +/***************************************************************************** + * Operations on pointer atomics + * _odp_atomic_ptr_init - no return value + * _odp_atomic_ptr_load - return current value + * _odp_atomic_ptr_store - no return value + * _odp_atomic_ptr_xchg - return old value + *****************************************************************************/ + +/** + * Initialization of pointer atomic variable + * + * @param ptr Pointer to a pointer atomic variable + * @param val Value to initialize the variable with + */ +static inline void _odp_atomic_ptr_init(_odp_atomic_ptr_t *ptr, void *val) +{ + __atomic_store_n(&ptr->v, val, __ATOMIC_RELAXED); +} + +/** + * Atomic load of pointer atomic variable + * + * @param ptr Pointer to a pointer atomic variable + * @param mmodel Memory model associated with the load operation + * + * @return Value of the variable + */ +static inline void *_odp_atomic_ptr_load(const _odp_atomic_ptr_t *ptr, + _odp_memmodel_t mmodel) +{ + return __atomic_load_n(&ptr->v, mmodel); +} + +/** + * Atomic store to pointer atomic variable + * + * @param ptr Pointer to a pointer atomic variable + * @param val Value to write to the atomic variable + * @param mmodel Memory model associated with the store operation + */ +static inline void _odp_atomic_ptr_store(_odp_atomic_ptr_t *ptr, + void *val, + _odp_memmodel_t mmodel) +{ + __atomic_store_n(&ptr->v, val, mmodel); +} + +/** + * Atomic exchange (swap) of pointer atomic variable + * + * @param ptr Pointer to a pointer atomic variable + * @param val New value to write + * @param mmodel Memory model associated with the exchange operation + * + * @return Old value of variable + */ +static inline void *_odp_atomic_ptr_xchg(_odp_atomic_ptr_t *ptr, + void *val, + _odp_memmodel_t mmodel) +{ + return __atomic_exchange_n(&ptr->v, val, mmodel); +} + +/** + * Atomic compare and exchange (swap) of pointer atomic variable + * "Strong" semantics, will not fail spuriously. + * + * @param ptr Pointer to a pointer atomic variable + * @param exp_p Pointer to expected value (updated on failure) + * @param val New value to write + * @param succ Memory model associated with a successful compare-and-swap + * operation + * @param fail Memory model associated with a failed compare-and-swap + * operation + * + * @return 1 (true) if exchange successful, 0 (false) if not successful (and + * '*exp_p' updated with current value) + */ +static inline int _odp_atomic_ptr_cmp_xchg_strong(_odp_atomic_ptr_t *ptr, + void **exp_p, + void *val, + _odp_memmodel_t succ, + _odp_memmodel_t fail) +{ + return __atomic_compare_exchange_n(&ptr->v, exp_p, val, + false/*strong*/, succ, fail); +} + +/***************************************************************************** + * Operations on flag atomics + * _odp_atomic_flag_init - no return value + * _odp_atomic_flag_load - return current value + * _odp_atomic_flag_tas - return old value + * _odp_atomic_flag_clear - no return value + * + * Flag atomics use Release Consistency memory consistency model, acquire + * model for TAS and release model for clear. + *****************************************************************************/ + +/** + * Initialize a flag atomic variable + * + * @param ptr Pointer to a flag atomic variable + * @param val The initial value (true or false) of the variable + */ +static inline void _odp_atomic_flag_init(_odp_atomic_flag_t *ptr, int val) +{ + __atomic_clear(ptr, __ATOMIC_RELAXED); + if (val) + __atomic_test_and_set(ptr, __ATOMIC_RELAXED); +} + +/** + * Load atomic flag variable + * @Note Load operation has relaxed memory model. + * + * @param ptr Pointer to a flag atomic variable + * @return The current value (true or false) of the variable + */ +static inline int _odp_atomic_flag_load(_odp_atomic_flag_t *ptr) +{ + return __atomic_load_n(ptr, __ATOMIC_RELAXED); +} + +/** + * Test-and-set of atomic flag variable + * @Note Operation has acquire memory model. It pairs with a later + * release operation in some thread. + * + * @param ptr Pointer to a flag atomic variable + * @return The old value (true or false) of the variable + */ +static inline int _odp_atomic_flag_tas(_odp_atomic_flag_t *ptr) +{ + return __atomic_test_and_set(ptr, __ATOMIC_ACQUIRE); +} + +/** + * Clear atomic flag variable + * The flag variable is cleared (set to the false value). + * @Note Operation has release memory model. It pairs with an earlier + * acquire operation in some thread. + * + * @param ptr Pointer to a flag atomic variable + */ +static inline void _odp_atomic_flag_clear(_odp_atomic_flag_t *ptr) +{ + __atomic_clear(ptr, __ATOMIC_RELEASE); +} + +/** + * @} + */ + +#ifdef __cplusplus +} +#endif + +#endif