X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Flibrte_eal%2Fcommon%2Finclude%2Farch%2Fx86%2Frte_atomic.h;h=148398f50ab748ef070c2f37c205927e03686057;hb=208393d67e2958079b57f20d5b8426813d19fe59;hp=4eac66631c1ab8b5ba6c9f54aafb3e19cdad063f;hpb=e8025211711a08257c4731a69bb5624d7de6d7c6;p=dpdk.git 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 4eac66631c..148398f50a 100644 --- a/lib/librte_eal/common/include/arch/x86/rte_atomic.h +++ b/lib/librte_eal/common/include/arch/x86/rte_atomic.h @@ -1,34 +1,5 @@ -/*- - * BSD LICENSE - * - * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * * Neither the name of Intel Corporation nor the names of its - * contributors may be used to endorse or promote products derived - * from this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR - * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT - * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +/* SPDX-License-Identifier: BSD-3-Clause + * Copyright(c) 2010-2014 Intel Corporation */ #ifndef _RTE_ATOMIC_X86_H_ @@ -40,6 +11,7 @@ extern "C" { #include #include +#include #include #include "generic/rte_atomic.h" @@ -55,18 +27,62 @@ extern "C" { #define rte_rmb() _mm_lfence() -#define rte_smp_mb() rte_mb() - #define rte_smp_wmb() rte_compiler_barrier() #define rte_smp_rmb() rte_compiler_barrier() +/* + * From Intel Software Development Manual; Vol 3; + * 8.2.2 Memory Ordering in P6 and More Recent Processor Families: + * ... + * . Reads are not reordered with other reads. + * . Writes are not reordered with older reads. + * . Writes to memory are not reordered with other writes, + * with the following exceptions: + * . streaming stores (writes) executed with the non-temporal move + * instructions (MOVNTI, MOVNTQ, MOVNTDQ, MOVNTPS, and MOVNTPD); and + * . string operations (see Section 8.2.4.1). + * ... + * . Reads may be reordered with older writes to different locations but not + * with older writes to the same location. + * . Reads or writes cannot be reordered with I/O instructions, + * locked instructions, or serializing instructions. + * . Reads cannot pass earlier LFENCE and MFENCE instructions. + * . Writes ... cannot pass earlier LFENCE, SFENCE, and MFENCE instructions. + * . LFENCE instructions cannot pass earlier reads. + * . SFENCE instructions cannot pass earlier writes ... + * . MFENCE instructions cannot pass earlier reads, writes ... + * + * As pointed by Java guys, that makes possible to use lock-prefixed + * instructions to get the same effect as mfence and on most modern HW + * that gives a better perfomance then using mfence: + * https://shipilev.net/blog/2014/on-the-fence-with-dependencies/ + * Basic idea is to use lock prefixed add with some dummy memory location + * as the destination. From their experiments 128B(2 cache lines) below + * current stack pointer looks like a good candidate. + * So below we use that techinque for rte_smp_mb() implementation. + */ + +static __rte_always_inline void +rte_smp_mb(void) +{ +#ifdef RTE_ARCH_I686 + asm volatile("lock addl $0, -128(%%esp); " ::: "memory"); +#else + asm volatile("lock addl $0, -128(%%rsp); " ::: "memory"); +#endif +} + #define rte_io_mb() rte_mb() #define rte_io_wmb() rte_compiler_barrier() #define rte_io_rmb() rte_compiler_barrier() +#define rte_cio_wmb() rte_compiler_barrier() + +#define rte_cio_rmb() rte_compiler_barrier() + /*------------------------- 16 bit atomic operations -------------------------*/ #ifndef RTE_FORCE_INTRINSICS @@ -88,6 +104,18 @@ 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); @@ -162,6 +190,18 @@ 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);