From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from wes1-so1.wedos.net (wes1-so1.wedos.net [46.28.106.15]) by dpdk.org (Postfix) with ESMTP id 48DB38D9A for ; Tue, 27 Oct 2015 20:16:15 +0100 (CET) Received: from pcviktorin.fit.vutbr.cz (pcviktorin.fit.vutbr.cz [147.229.13.147]) by wes1-so1.wedos.net (Postfix) with ESMTPSA id 3nljSH0jQRz3qw; Tue, 27 Oct 2015 20:16:15 +0100 (CET) From: Jan Viktorin To: dev@dpdk.org, David Hunt , David Marchand , "Ananyev, Konstantin" Date: Tue, 27 Oct 2015 20:13:37 +0100 Message-Id: <1445973229-22058-6-git-send-email-viktorin@rehivetech.com> X-Mailer: git-send-email 2.6.1 In-Reply-To: <1445973229-22058-1-git-send-email-viktorin@rehivetech.com> References: <1445877458-31052-1-git-send-email-viktorin@rehivetech.com> <1445973229-22058-1-git-send-email-viktorin@rehivetech.com> Subject: [dpdk-dev] [PATCH v3 05/17] eal/arm: implement rdtsc by PMU or clock_gettime X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Oct 2015 19:16:15 -0000 Enable to choose a preferred way to read timer based on the configuration entry CONFIG_RTE_ARM_EAL_RDTSC_USE_PMU. It requires a kernel module that is not included to work. Based on the patch by David Hunt and Armuta Zende: lib: added support for armv7 architecture Signed-off-by: Jan Viktorin Signed-off-by: Amruta Zende Signed-off-by: David Hunt --- .../common/include/arch/arm/rte_cycles.h | 38 +++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles.h b/lib/librte_eal/common/include/arch/arm/rte_cycles.h index ff66ae2..5dcef25 100644 --- a/lib/librte_eal/common/include/arch/arm/rte_cycles.h +++ b/lib/librte_eal/common/include/arch/arm/rte_cycles.h @@ -54,8 +54,14 @@ extern "C" { * @return * The time base for this lcore. */ +#ifndef CONFIG_RTE_ARM_EAL_RDTSC_USE_PMU + +/** + * This call is easily portable to any ARM architecture, however, + * it may be damn slow and inprecise for some tasks. + */ static inline uint64_t -rte_rdtsc(void) +__rte_rdtsc_syscall(void) { struct timespec val; uint64_t v; @@ -67,6 +73,36 @@ rte_rdtsc(void) v += (uint64_t) val.tv_nsec; return v; } +#define rte_rdtsc __rte_rdtsc_syscall + +#else + +/** + * This function requires to configure the PMCCNTR and enable + * userspace access to it: + * + * asm volatile("mcr p15, 0, %0, c9, c14, 0" : : "r"(1)); + * asm volatile("mcr p15, 0, %0, c9, c12, 0" : : "r"(29)); + * asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r"(0x8000000f)); + * + * which is possible only from the priviledged mode (kernel space). + */ +static inline uint64_t +__rte_rdtsc_pmccntr(void) +{ + unsigned tsc; + uint64_t final_tsc; + + /* Read PMCCNTR */ + asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(tsc)); + /* 1 tick = 64 clocks */ + final_tsc = ((uint64_t)tsc) << 6; + + return (uint64_t)final_tsc; +} +#define rte_rdtsc __rte_rdtsc_pmccntr + +#endif /* RTE_ARM_EAL_RDTSC_USE_PMU */ static inline uint64_t rte_rdtsc_precise(void) -- 2.6.1