From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3CE1C4332F for ; Fri, 10 Sep 2021 19:28:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFCBA611CE for ; Fri, 10 Sep 2021 19:28:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234049AbhIJTaF (ORCPT ); Fri, 10 Sep 2021 15:30:05 -0400 Received: from esa5.hgst.iphmx.com ([216.71.153.144]:29548 "EHLO esa5.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232697AbhIJT3e (ORCPT ); Fri, 10 Sep 2021 15:29:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1631302102; x=1662838102; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=EwPH8S2shtkXPtK91LcmbvBxHJQny+yb+LwDXIyqGOc=; b=j2fBEIIB2Ft1JFBPinmoj7mQNAR6HqqPYEBN37ehzNlQKJ9bUEKds2tV 5T/2X6Rqq30PHwoFZur3ALKFc5Thv3ngGlb1vebK6ivdjXaam2i4+K1XX ZTxO9ANsLYEENwMuV1gx/nVZMFvXq8/lvAc+pUbgvj0+oKPy42MoaiRME Hd1zRQAC6b3Iq9y6KxpJKUYSUkQbAkG3/oTTM4cSVbPR4d28x8bITJSvy WT9ijxJDFcFt5Q3QUZl8K6xRuPKkC0JgAv/bUR9oX8ehnVKGDkTqZ09R3 S2NDSwfUEJGReBmksqoNXweRNYEkknzysw4x4a+vl7lKtoRx/QTVjr801 Q==; X-IronPort-AV: E=Sophos;i="5.85,283,1624291200"; d="scan'208";a="179706173" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 11 Sep 2021 03:28:21 +0800 IronPort-SDR: Xg+tmhDuaJhbO7IX1GjaOOB4T28MM8BHel6tLkj2FH0DqKi0hSesPo7ft5icCjjSFZb7lf5D2y 1cTsA34He3Kyp6Ti/MWHe3NOUHGuJcC2BfBy/g9erl0ikBg7bozvjlG16FaKtEy78XE9RTCExB Q/+IT2nLBAjDcZ9LAwiWt4XlQ9ztW/h63MzCiXQhJQyc7LxErDf2cTKk1uM+c6cyTP5DuHVcUx gAeow4ItpdDr4uqxAgifELw7Isq/9x3qIan1Th8w0/4Thx1lmfZ4MTbcFa1XHyCdAwiClYtOhU SAxvMFIpkZ/ua+SpNICL+4h1 Received: from uls-op-cesaip01.wdc.com ([10.248.3.36]) by uls-op-cesaep02.wdc.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Sep 2021 12:03:16 -0700 IronPort-SDR: nPSEnoM5BDTrXlc0+cTbP6KkjikRYcijTCnBUjY87wVNLQN92bAnao9h421g3jMCxwUy0O9DW/ bjv3DfmnysavGNXow0K2mq/Llaxh3kBVXb1bNerrprNT7JTMAH3HyKOGrAqhFsuZZe3fOiYCee IuXmPWXms6BCvxAKYY4v6CSy5wiQrRc2zY6aH07+nFtZSYRCZXOGOD1Y5o4xfMAKZF7Zu05BLc 8OusOABMaXMOPIoRud+FrLLDZbbXpbbMH80n79ON8cvPdZjv/u+V1rIojA0XmMOKe0fGm+IWQT yV8= WDCIronportException: Internal Received: from unknown (HELO hulk.wdc.com) ([10.225.167.73]) by uls-op-cesaip01.wdc.com with ESMTP; 10 Sep 2021 12:28:21 -0700 From: Atish Patra To: linux-kernel@vger.kernel.org Cc: Atish Patra , Alexander Shishkin , Anup Patel , Ard Biesheuvel , "Darrick J. Wong" , devicetree@vger.kernel.org, Guo Ren , Heinrich Schuchardt , Jiri Olsa , John Garry , Jonathan Corbet , linux-doc@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-riscv@lists.infradead.org, Nick Kossifidis , Palmer Dabbelt , Paul Walmsley , Rob Herring , Vincent Chen Subject: [v3 04/10] RISC-V: Add a simple platform driver for RISC-V legacy perf Date: Fri, 10 Sep 2021 12:27:51 -0700 Message-Id: <20210910192757.2309100-5-atish.patra@wdc.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210910192757.2309100-1-atish.patra@wdc.com> References: <20210910192757.2309100-1-atish.patra@wdc.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The old RISC-V perf implementation allowed counting of only cycle/instruction counters using perf. Restore that feature by implementing a simple platform driver under a separate config to provide backward compatibility. Any existing software stack will continue to work as it is. However, it provides an easy way out in future where we can remove the legacy driver. Signed-off-by: Atish Patra --- drivers/perf/Kconfig | 9 ++ drivers/perf/Makefile | 3 + drivers/perf/riscv_pmu_legacy.c | 143 ++++++++++++++++++++++++++++++++ include/linux/perf/riscv_pmu.h | 2 + 4 files changed, 157 insertions(+) create mode 100644 drivers/perf/riscv_pmu_legacy.c diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig index fc42ab613ea0..1546a487d970 100644 --- a/drivers/perf/Kconfig +++ b/drivers/perf/Kconfig @@ -64,6 +64,15 @@ config RISCV_PMU Say y if you want to use CPU performance monitors on RISCV-based systems. +config RISCV_PMU_LEGACY + depends on RISCV_PMU + bool "RISC-V legacy PMU implementation" + default y + help + Say y if you want to use the legacy CPU performance monitor + implementation on RISC-V based systems. This only allows counting + of cycle/instruction counter and will be removed in future. + config ARM_PMU_ACPI depends on ARM_PMU && ACPI def_bool y diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile index 76e5c50e24bb..e8aa666a9d28 100644 --- a/drivers/perf/Makefile +++ b/drivers/perf/Makefile @@ -11,6 +11,9 @@ obj-$(CONFIG_HISI_PMU) += hisilicon/ obj-$(CONFIG_QCOM_L2_PMU) += qcom_l2_pmu.o obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o obj-$(CONFIG_RISCV_PMU) += riscv_pmu.o +ifeq ($(CONFIG_RISCV_PMU), y) +obj-$(CONFIG_RISCV_PMU_LEGACY) += riscv_pmu_legacy.o +endif obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o diff --git a/drivers/perf/riscv_pmu_legacy.c b/drivers/perf/riscv_pmu_legacy.c new file mode 100644 index 000000000000..8bb973f2d9f7 --- /dev/null +++ b/drivers/perf/riscv_pmu_legacy.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RISC-V performance counter support. + * + * Copyright (C) 2021 Western Digital Corporation or its affiliates. + * + * This implementation is based on old RISC-V perf and ARM perf event code + * which are in turn based on sparc64 and x86 code. + */ + +#include +#include +#include + +#define RISCV_PMU_LEGACY_CYCLE 0 +#define RISCV_PMU_LEGACY_INSTRET 1 +#define RISCV_PMU_LEGACY_NUM_CTR 2 + +bool pmu_init_done; + +static int pmu_legacy_ctr_get_idx(struct perf_event *event) +{ + struct perf_event_attr *attr = &event->attr; + + if (event->attr.type != PERF_TYPE_HARDWARE) + return -EOPNOTSUPP; + if (attr->config == PERF_COUNT_HW_CPU_CYCLES) + return RISCV_PMU_LEGACY_CYCLE; + else if (attr->config == PERF_COUNT_HW_INSTRUCTIONS) + return RISCV_PMU_LEGACY_INSTRET; + else + return -EOPNOTSUPP; +} + +/* For legacy config & counter index are same */ +static int pmu_legacy_event_map(struct perf_event *event, u64 *config) +{ + return pmu_legacy_ctr_get_idx(event); +} + +static u64 pmu_legacy_read_ctr(struct perf_event *event) +{ + struct hw_perf_event *hwc = &event->hw; + int idx = hwc->idx; + u64 val; + + if (idx == RISCV_PMU_LEGACY_CYCLE) { + val = riscv_pmu_ctr_read_csr(CSR_CYCLE); + if (IS_ENABLED(CONFIG_32BIT)) + val = (u64)riscv_pmu_ctr_read_csr(CSR_CYCLEH) << 32 | val; + } else if (idx == RISCV_PMU_LEGACY_INSTRET) { + val = riscv_pmu_ctr_read_csr(CSR_INSTRET); + if (IS_ENABLED(CONFIG_32BIT)) + val = ((u64)riscv_pmu_ctr_read_csr(CSR_INSTRETH)) << 32 | val; + } else + return 0; + + return val; +} + +static void pmu_legacy_ctr_start(struct perf_event *event, u64 ival) +{ + struct hw_perf_event *hwc = &event->hw; + u64 initial_val = pmu_legacy_read_ctr(event); + + /** + * The legacy method doesn't really have a start/stop method. + * It also can not update the counter with a initial value. + * But we still need to set the prev_count so that read() can compute + * the delta. Just use the current counter value to set the prev_count. + */ + local64_set(&hwc->prev_count, initial_val); +} + +/** + * This is just a simple implementation to allow legacy implementations + * compatible with new RISC-V PMU driver framework. + * This driver only allows reading two counters i.e CYCLE & INSTRET. + * However, it can not start or stop the counter. Thus, it is not very useful + * will be removed in future. + */ +static void pmu_legacy_init(struct riscv_pmu *pmu) +{ + pr_info("Legacy PMU implementation is available\n"); + + pmu->num_counters = RISCV_PMU_LEGACY_NUM_CTR; + pmu->ctr_start = pmu_legacy_ctr_start; + pmu->ctr_stop = NULL; + pmu->event_map = pmu_legacy_event_map; + pmu->ctr_get_idx = pmu_legacy_ctr_get_idx; + pmu->ctr_get_width = NULL; + pmu->ctr_clear_idx = NULL; + pmu->ctr_read = pmu_legacy_read_ctr; + + perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW); +} + +static int pmu_legacy_device_probe(struct platform_device *pdev) +{ + struct riscv_pmu *pmu = NULL; + + pmu = riscv_pmu_alloc(); + if (!pmu) + return -ENOMEM; + pmu_legacy_init(pmu); + + return 0; +} + +static struct platform_driver pmu_legacy_driver = { + .probe = pmu_legacy_device_probe, + .driver = { + .name = RISCV_PMU_LEGACY_PDEV_NAME, + }, +}; + +static int __init riscv_pmu_legacy_devinit(void) +{ + int ret; + struct platform_device *pdev; + + if (likely(pmu_init_done)) + return 0; + + ret = platform_driver_register(&pmu_legacy_driver); + if (ret) + return ret; + + pdev = platform_device_register_simple(RISCV_PMU_LEGACY_PDEV_NAME, -1, NULL, 0); + if (IS_ERR(pdev)) { + platform_driver_unregister(&pmu_legacy_driver); + return PTR_ERR(pdev); + } + + return ret; +} +late_initcall(riscv_pmu_legacy_devinit); + +void riscv_pmu_legacy_init(bool done) +{ + if (done) + pmu_init_done = true; +} diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h index 564129839e19..f3bce79d8998 100644 --- a/include/linux/perf/riscv_pmu.h +++ b/include/linux/perf/riscv_pmu.h @@ -22,6 +22,7 @@ #define RISCV_MAX_COUNTERS 64 #define RISCV_OP_UNSUPP (-EOPNOTSUPP) #define RISCV_PMU_PDEV_NAME "riscv-pmu" +#define RISCV_PMU_LEGACY_PDEV_NAME "riscv-pmu-legacy" #define RISCV_PMU_STOP_FLAG_RESET 1 @@ -58,6 +59,7 @@ struct riscv_pmu { unsigned long riscv_pmu_ctr_read_csr(unsigned long csr); int riscv_pmu_event_set_period(struct perf_event *event, u64 *init_val); u64 riscv_pmu_event_update(struct perf_event *event); +void riscv_pmu_legacy_init(bool init_done); struct riscv_pmu *riscv_pmu_alloc(void); #endif /* CONFIG_RISCV_PMU */ -- 2.31.1