From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id A629B456A3; Fri, 26 Jul 2024 19:15:49 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 5C3A242FBB; Fri, 26 Jul 2024 19:15:45 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mails.dpdk.org (Postfix) with ESMTP id DF03642E4C for ; Fri, 26 Jul 2024 19:15:42 +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 C49901007; Fri, 26 Jul 2024 10:16:07 -0700 (PDT) Received: from ampere-altra-2-1.usa.Arm.com (ampere-altra-2-1.usa.arm.com [10.118.91.158]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id EEF453FB75; Fri, 26 Jul 2024 10:15:41 -0700 (PDT) From: Wathsala Vithanage To: Thomas Monjalon , Tyler Retzlaff , Ruifeng Wang Cc: honnappa.nagarahalli@arm.com, dev@dpdk.org, Wathsala Vithanage , Dhruv Tripathi , Jack Bond-Preston , Nick Connolly , Vinod Krishna Subject: [PATCH v4 3/4] eal: add Arm WFET in power management intrinsics Date: Fri, 26 Jul 2024 17:15:26 +0000 Message-Id: <20240726171528.2245682-3-wathsala.vithanage@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240726171528.2245682-1-wathsala.vithanage@arm.com> References: <20240604044401.3577707-1-wathsala.vithanage@arm.com> <20240726171528.2245682-1-wathsala.vithanage@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Wait for event with timeout (WFET) puts the CPU in a low power mode and stays there until an event is signalled (SEV), loss of an exclusive monitor or a timeout. WFET is enabled selectively by checking FEAT_WFxT in Linux auxiliary vector. If FEAT_WFxT is not available power management will fallback to WFE. WFE is available on all the Arm platforms supported by DPDK. Therefore, the RTE_ARM_USE_WFE macro is not required to enable the WFE feature for PMD power monitoring.  RTE_ARM_USE_WFE is used at the build time to use the WFE instruction where applicable in the code at the developer's discretion rather than as an indicator of the instruction's availability. Signed-off-by: Wathsala Vithanage Reviewed-by: Dhruv Tripathi Reviewed-by: Honnappa Nagarahalli Reviewed-by: Jack Bond-Preston Reviewed-by: Nick Connolly Reviewed-by: Vinod Krishna --- .mailmap | 1 + app/test/test_cpuflags.c | 3 +++ lib/eal/arm/include/rte_cpuflags_64.h | 3 +++ lib/eal/arm/include/rte_pause_64.h | 16 +++++++++-- lib/eal/arm/rte_cpuflags.c | 1 + lib/eal/arm/rte_power_intrinsics.c | 39 ++++++++++++++++++--------- 6 files changed, 49 insertions(+), 14 deletions(-) diff --git a/.mailmap b/.mailmap index 9c28b74655..a5c49d3702 100644 --- a/.mailmap +++ b/.mailmap @@ -1540,6 +1540,7 @@ Vincent Li Vincent S. Cojot Vinh Tran Vipin Padmam Ramesh +Vinod Krishna Vipin Varghese Vipul Ashri Visa Hankala diff --git a/app/test/test_cpuflags.c b/app/test/test_cpuflags.c index a0ff74720c..22ab4dff0a 100644 --- a/app/test/test_cpuflags.c +++ b/app/test/test_cpuflags.c @@ -156,6 +156,9 @@ test_cpuflags(void) printf("Check for SVEBF16:\t"); CHECK_FOR_FLAG(RTE_CPUFLAG_SVEBF16); + + printf("Check for WFXT:\t"); + CHECK_FOR_FLAG(RTE_CPUFLAG_WFXT); #endif #if defined(RTE_ARCH_X86_64) || defined(RTE_ARCH_I686) diff --git a/lib/eal/arm/include/rte_cpuflags_64.h b/lib/eal/arm/include/rte_cpuflags_64.h index afe70209c3..993d980a02 100644 --- a/lib/eal/arm/include/rte_cpuflags_64.h +++ b/lib/eal/arm/include/rte_cpuflags_64.h @@ -36,6 +36,9 @@ enum rte_cpu_flag_t { RTE_CPUFLAG_SVEF64MM, RTE_CPUFLAG_SVEBF16, RTE_CPUFLAG_AARCH64, + + /* WFET and WFIT instructions */ + RTE_CPUFLAG_WFXT, }; #include "generic/rte_cpuflags.h" diff --git a/lib/eal/arm/include/rte_pause_64.h b/lib/eal/arm/include/rte_pause_64.h index 8224f09ba7..809403bffa 100644 --- a/lib/eal/arm/include/rte_pause_64.h +++ b/lib/eal/arm/include/rte_pause_64.h @@ -24,15 +24,27 @@ static inline void rte_pause(void) asm volatile("yield" ::: "memory"); } -/* Send a local event to quit WFE. */ +/* Send a local event to quit WFE/WFxT. */ #define __RTE_ARM_SEVL() { asm volatile("sevl" : : : "memory"); } -/* Send a global event to quit WFE for all cores. */ +/* Send a global event to quit WFE/WFxT for all cores. */ #define __RTE_ARM_SEV() { asm volatile("sev" : : : "memory"); } /* Put processor into low power WFE(Wait For Event) state. */ #define __RTE_ARM_WFE() { asm volatile("wfe" : : : "memory"); } +/* Put processor into low power WFET (WFE with Timeout) state. */ +#ifdef RTE_ARM_FEATURE_WFXT +#define __RTE_ARM_WFET(t) { \ + asm volatile("wfet %x[to]" \ + : \ + : [to] "r" (t) \ + : "memory"); \ + } +#else +#define __RTE_ARM_WFET(t) { RTE_SET_USED(t); } +#endif + /* * Atomic exclusive load from addr, it returns the 8-bit content of * *addr while making it 'monitored', when it is written by someone diff --git a/lib/eal/arm/rte_cpuflags.c b/lib/eal/arm/rte_cpuflags.c index 29884c285f..88e10c6da0 100644 --- a/lib/eal/arm/rte_cpuflags.c +++ b/lib/eal/arm/rte_cpuflags.c @@ -115,6 +115,7 @@ const struct feature_entry rte_cpu_feature_table[] = { FEAT_DEF(SVEF32MM, REG_HWCAP2, 10) FEAT_DEF(SVEF64MM, REG_HWCAP2, 11) FEAT_DEF(SVEBF16, REG_HWCAP2, 12) + FEAT_DEF(WFXT, REG_HWCAP2, 31) FEAT_DEF(AARCH64, REG_PLATFORM, 0) }; #endif /* RTE_ARCH */ diff --git a/lib/eal/arm/rte_power_intrinsics.c b/lib/eal/arm/rte_power_intrinsics.c index b0056cce8b..6475bbca04 100644 --- a/lib/eal/arm/rte_power_intrinsics.c +++ b/lib/eal/arm/rte_power_intrinsics.c @@ -4,19 +4,32 @@ #include +#include "rte_cpuflags.h" #include "rte_power_intrinsics.h" /** - * This function uses WFE instruction to make lcore suspend + * Set wfet_en if WFET is supported + */ +#ifdef RTE_ARCH_64 +static uint8_t wfet_en; +#endif /* RTE_ARCH_64 */ + +RTE_INIT(rte_power_intrinsics_init) +{ +#ifdef RTE_ARCH_64 + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_WFXT)) + wfet_en = 1; +#endif /* RTE_ARCH_64 */ +} + +/** + * This function uses WFE/WFET instruction to make lcore suspend * execution on ARM. - * Note that timestamp based timeout is not supported yet. */ int rte_power_monitor(const struct rte_power_monitor_cond *pmc, const uint64_t tsc_timestamp) { - RTE_SET_USED(tsc_timestamp); - #ifdef RTE_ARCH_64 const unsigned int lcore_id = rte_lcore_id(); uint64_t cur_value; @@ -33,28 +46,30 @@ rte_power_monitor(const struct rte_power_monitor_cond *pmc, switch (pmc->size) { case sizeof(uint8_t): - __RTE_ARM_LOAD_EXC_8(pmc->addr, cur_value, rte_memory_order_relaxed) - __RTE_ARM_WFE() + __RTE_ARM_LOAD_EXC_8(pmc->addr, cur_value, rte_memory_order_relaxed); break; case sizeof(uint16_t): - __RTE_ARM_LOAD_EXC_16(pmc->addr, cur_value, rte_memory_order_relaxed) - __RTE_ARM_WFE() + __RTE_ARM_LOAD_EXC_16(pmc->addr, cur_value, rte_memory_order_relaxed); break; case sizeof(uint32_t): - __RTE_ARM_LOAD_EXC_32(pmc->addr, cur_value, rte_memory_order_relaxed) - __RTE_ARM_WFE() + __RTE_ARM_LOAD_EXC_32(pmc->addr, cur_value, rte_memory_order_relaxed); break; case sizeof(uint64_t): - __RTE_ARM_LOAD_EXC_64(pmc->addr, cur_value, rte_memory_order_relaxed) - __RTE_ARM_WFE() + __RTE_ARM_LOAD_EXC_64(pmc->addr, cur_value, rte_memory_order_relaxed); break; default: return -EINVAL; /* unexpected size */ } + if (wfet_en) + __RTE_ARM_WFET(tsc_timestamp) + else + __RTE_ARM_WFE() + return 0; #else RTE_SET_USED(pmc); + RTE_SET_USED(tsc_timestamp); return -ENOTSUP; #endif /* RTE_ARCH_64 */ -- 2.34.1