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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 9A111C432BE for ; Fri, 23 Jul 2021 12:46:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 768D260E53 for ; Fri, 23 Jul 2021 12:46:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234917AbhGWMFu (ORCPT ); Fri, 23 Jul 2021 08:05:50 -0400 Received: from foss.arm.com ([217.140.110.172]:45434 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234601AbhGWMFs (ORCPT ); Fri, 23 Jul 2021 08:05:48 -0400 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 1050E1063; Fri, 23 Jul 2021 05:46:22 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 97FCD3F694; Fri, 23 Jul 2021 05:46:20 -0700 (PDT) From: Suzuki K Poulose To: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, tamas.zsoldos@arm.com, al.grant@arm.com, leo.yan@linaro.org, mike.leach@linaro.org, mathieu.poirier@linaro.org, suzuki.poulose@arm.com, anshuman.khandual@arm.com, jinlmao@qti.qualcomm.com Subject: [PATCH v2 01/10] coresight: etm4x: Save restore TRFCR_EL1 Date: Fri, 23 Jul 2021 13:46:02 +0100 Message-Id: <20210723124611.3828908-2-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20210723124611.3828908-1-suzuki.poulose@arm.com> References: <20210723124611.3828908-1-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the CPU enters a low power mode, the TRFCR_EL1 contents could be reset. Thus we need to save/restore the TRFCR_EL1 along with the ETM4x registers to allow the tracing. The TRFCR related helpers are in a new header file, as we need to use them for TRBE in the later patches. Cc: Mathieu Poirier Cc: Anshuman Khandual Cc: Mike Leach Cc: Leo Yan Signed-off-by: Suzuki K Poulose --- Changes since v1: - Moved the TRFCR helpers in to a new header file --- .../coresight/coresight-etm4x-core.c | 43 +++++++++++++------ drivers/hwtracing/coresight/coresight-etm4x.h | 2 + .../coresight/coresight-self-hosted-trace.h | 25 +++++++++++ 3 files changed, 58 insertions(+), 12 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-self-hosted-trace.h diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index da27cd4a3c38..3e548dac9b05 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -39,6 +39,7 @@ #include "coresight-etm4x.h" #include "coresight-etm-perf.h" +#include "coresight-self-hosted-trace.h" static int boot_enable; module_param(boot_enable, int, 0444); @@ -985,7 +986,7 @@ static void cpu_enable_tracing(struct etmv4_drvdata *drvdata) if (is_kernel_in_hyp_mode()) trfcr |= TRFCR_EL2_CX; - write_sysreg_s(trfcr, SYS_TRFCR_EL1); + write_trfcr(trfcr); } static void etm4_init_arch_data(void *info) @@ -1528,7 +1529,7 @@ static void etm4_init_trace_id(struct etmv4_drvdata *drvdata) drvdata->trcid = coresight_get_trace_id(drvdata->cpu); } -static int etm4_cpu_save(struct etmv4_drvdata *drvdata) +static int __etm4_cpu_save(struct etmv4_drvdata *drvdata) { int i, ret = 0; struct etmv4_save_state *state; @@ -1667,7 +1668,23 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata) return ret; } -static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) +static int etm4_cpu_save(struct etmv4_drvdata *drvdata) +{ + int ret = 0; + + /* Save the TRFCR irrespective of whether the ETM is ON */ + if (drvdata->trfc) + drvdata->save_trfcr = read_trfcr(); + /* + * Save and restore the ETM Trace registers only if + * the ETM is active. + */ + if (local_read(&drvdata->mode) && drvdata->save_state) + ret = __etm4_cpu_save(drvdata); + return ret; +} + +static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata) { int i; struct etmv4_save_state *state = drvdata->save_state; @@ -1763,6 +1780,14 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) etm4_cs_lock(drvdata, csa); } +static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) +{ + if (drvdata->trfc) + write_trfcr(drvdata->save_trfcr); + if (drvdata->state_needs_restore) + __etm4_cpu_restore(drvdata); +} + static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, void *v) { @@ -1774,23 +1799,17 @@ static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, drvdata = etmdrvdata[cpu]; - if (!drvdata->save_state) - return NOTIFY_OK; - if (WARN_ON_ONCE(drvdata->cpu != cpu)) return NOTIFY_BAD; switch (cmd) { case CPU_PM_ENTER: - /* save the state if self-hosted coresight is in use */ - if (local_read(&drvdata->mode)) - if (etm4_cpu_save(drvdata)) - return NOTIFY_BAD; + if (etm4_cpu_save(drvdata)) + return NOTIFY_BAD; break; case CPU_PM_EXIT: case CPU_PM_ENTER_FAILED: - if (drvdata->state_needs_restore) - etm4_cpu_restore(drvdata); + etm4_cpu_restore(drvdata); break; default: return NOTIFY_DONE; diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index e5b79bdb9851..82cba16b73a6 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -921,6 +921,7 @@ struct etmv4_save_state { * @lpoverride: If the implementation can support low-power state over. * @trfc: If the implementation supports Arm v8.4 trace filter controls. * @config: structure holding configuration parameters. + * @save_trfcr: Saved TRFCR_EL1 register during a CPU PM event. * @save_state: State to be preserved across power loss * @state_needs_restore: True when there is context to restore after PM exit * @skip_power_up: Indicates if an implementation can skip powering up @@ -973,6 +974,7 @@ struct etmv4_drvdata { bool lpoverride; bool trfc; struct etmv4_config config; + u64 save_trfcr; struct etmv4_save_state *save_state; bool state_needs_restore; bool skip_power_up; diff --git a/drivers/hwtracing/coresight/coresight-self-hosted-trace.h b/drivers/hwtracing/coresight/coresight-self-hosted-trace.h new file mode 100644 index 000000000000..53b35a28075e --- /dev/null +++ b/drivers/hwtracing/coresight/coresight-self-hosted-trace.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +/* + * Arm v8 Self-Hosted trace support. + * + * Copyright (C) 2021 ARM Ltd. + */ + +#ifndef __CORESIGHT_SELF_HOSTED_TRACE_H +#define __CORESIGHT_SELF_HOSTED_TRACE_H + +#include + +static inline u64 read_trfcr(void) +{ + return read_sysreg_s(SYS_TRFCR_EL1); +} + +static inline void write_trfcr(u64 val) +{ + write_sysreg_s(val, SYS_TRFCR_EL1); + isb(); +} + +#endif /* __CORESIGHT_SELF_HOSTED_TRACE_H */ -- 2.24.1