From patchwork Fri Aug 16 15:46:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 11097893 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6FB4717E2 for ; Fri, 16 Aug 2019 15:46:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5A1BE28640 for ; Fri, 16 Aug 2019 15:46:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4DB61288A9; Fri, 16 Aug 2019 15:46:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 2A7E228640 for ; Fri, 16 Aug 2019 15:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ud5cbqgdFarbbigy13H9gFeVRXJNtOvP76ATGB1C2fU=; b=Y5pgbiPV8AOZNR J+Uo5zD9nbCByXr/FyHQdtLEep4WmgkwdjqdnERlOZ0I7TB6A30z/+d2PDKmkV/sGKU6EMStTm1o1 S+6vfH9avh/khtDKu3+jZiyua1JpVJPUGBqWYGPeoiiwGQC7R/bSQtCroEn9k3TdJPU89jKuDGF3P 9e+ACO4bNIYvXQMigkXlGf84Co9uYbTGjYxG6vCmn19dN9EOhrAkMa30TKWw1ujv25yVzBMvD8VR5 970LTVgd7jYEo1Cjg+QOhhgiv+WI9M3nNO+TP5tqgoz3IE7n+pTnj7aNfRXQliA19aHs2NKT9H1qr y2pXMc7mQKa7CCLbiMlg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeR3-00029A-E2; Fri, 16 Aug 2019 15:46:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeQq-0001oc-6J for linux-arm-kernel@lists.infradead.org; Fri, 16 Aug 2019 15:46:26 +0000 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 C7BB6360; Fri, 16 Aug 2019 08:46:23 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E94903F694; Fri, 16 Aug 2019 08:46:21 -0700 (PDT) From: Andrew Murray To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin Subject: [PATCH v5 1/3] coresight: etm4x: save/restore state across CPU low power states Date: Fri, 16 Aug 2019 16:46:13 +0100 Message-Id: <20190816154615.39854-2-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190816154615.39854-1-andrew.murray@arm.com> References: <20190816154615.39854-1-andrew.murray@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190816_084624_320169_05D20440 X-CRM114-Status: GOOD ( 21.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Al.Grant@arm.com, coresight@lists.linaro.org, Leo Yan , Sudeep Holla , linux-arm-kernel@lists.infradead.org, Mike Leach Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some hardware will ignore bit TRCPDCR.PU which is used to signal to hardware that power should not be removed from the trace unit. Let's mitigate against this by conditionally saving and restoring the trace unit state when the CPU enters low power states. This patchset introduces a firmware property named 'arm,coresight-loses-context-with-cpu' - when this is present the hardware state will be conditionally saved and restored. A module parameter 'pm_save_enable' is also introduced which can be configured to override the firmware property. This can be set to never allow save/restore or to conditionally allow it (only for self-hosted). The default value is determined by firmware. We avoid saving the hardware state when self-hosted coresight isn't in use to reduce PM latency - we can't determine this by reading the claim tags (TRCCLAIMCLR) as these are 'trace' registers which need power and clocking, something we can't easily provide in the PM context. Therefore we rely on the existing drvdata->mode internal state that is set when self-hosted coresight is used (and powered). Signed-off-by: Andrew Murray Reviewed-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-etm4x.c | 318 ++++++++++++++++++ drivers/hwtracing/coresight/coresight-etm4x.h | 64 ++++ drivers/hwtracing/coresight/coresight.c | 6 + include/linux/coresight.h | 6 + 4 files changed, 394 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index a128b5063f46..35a524eec36d 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -26,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -37,6 +39,15 @@ static int boot_enable; module_param(boot_enable, int, 0444); MODULE_PARM_DESC(boot_enable, "Enable tracing on boot"); +#define PARAM_PM_SAVE_FIRMWARE 0 /* save self-hosted state as per firmware */ +#define PARAM_PM_SAVE_NEVER 1 /* never save any state */ +#define PARAM_PM_SAVE_SELF_HOSTED 2 /* save self-hosted state only */ + +static int pm_save_enable = PARAM_PM_SAVE_FIRMWARE; +module_param(pm_save_enable, int, 0444); +MODULE_PARM_DESC(pm_save_enable, + "Save/restore state on power down: 1 = never, 2 = self-hosted"); + /* The number of ETMv4 currently registered */ static int etm4_count; static struct etmv4_drvdata *etmdrvdata[NR_CPUS]; @@ -54,6 +65,14 @@ static void etm4_os_unlock(struct etmv4_drvdata *drvdata) isb(); } +static void etm4_os_lock(struct etmv4_drvdata *drvdata) +{ + /* Writing 0x1 to TRCOSLAR locks the trace registers */ + writel_relaxed(0x1, drvdata->base + TRCOSLAR); + drvdata->os_unlock = false; + isb(); +} + static bool etm4_arch_supported(u8 arch) { /* Mask out the minor version number */ @@ -1085,6 +1104,288 @@ static void etm4_init_trace_id(struct etmv4_drvdata *drvdata) drvdata->trcid = coresight_get_trace_id(drvdata->cpu); } +#ifdef CONFIG_CPU_PM +static int etm4_cpu_save(struct etmv4_drvdata *drvdata) +{ + int i, ret = 0; + struct etmv4_save_state *state; + struct device *etm_dev = &drvdata->csdev->dev; + + /* + * As recommended by 3.4.1 ("The procedure when powering down the PE") + * of ARM IHI 0064D + */ + dsb(sy); + isb(); + + CS_UNLOCK(drvdata->base); + + /* Lock the OS lock to disable trace and external debugger access */ + etm4_os_lock(drvdata); + + /* wait for TRCSTATR.PMSTABLE to go up */ + if (coresight_timeout(drvdata->base, TRCSTATR, + TRCSTATR_PMSTABLE_BIT, 1)) { + dev_err(etm_dev, + "timeout while waiting for PM Stable Status\n"); + etm4_os_unlock(drvdata); + ret = -EBUSY; + goto out; + } + + state = drvdata->save_state; + + state->trcprgctlr = readl(drvdata->base + TRCPRGCTLR); + state->trcprocselr = readl(drvdata->base + TRCPROCSELR); + state->trcconfigr = readl(drvdata->base + TRCCONFIGR); + state->trcauxctlr = readl(drvdata->base + TRCAUXCTLR); + state->trceventctl0r = readl(drvdata->base + TRCEVENTCTL0R); + state->trceventctl1r = readl(drvdata->base + TRCEVENTCTL1R); + state->trcstallctlr = readl(drvdata->base + TRCSTALLCTLR); + state->trctsctlr = readl(drvdata->base + TRCTSCTLR); + state->trcsyncpr = readl(drvdata->base + TRCSYNCPR); + state->trcccctlr = readl(drvdata->base + TRCCCCTLR); + state->trcbbctlr = readl(drvdata->base + TRCBBCTLR); + state->trctraceidr = readl(drvdata->base + TRCTRACEIDR); + state->trcqctlr = readl(drvdata->base + TRCQCTLR); + + state->trcvictlr = readl(drvdata->base + TRCVICTLR); + state->trcviiectlr = readl(drvdata->base + TRCVIIECTLR); + state->trcvissctlr = readl(drvdata->base + TRCVISSCTLR); + state->trcvipcssctlr = readl(drvdata->base + TRCVIPCSSCTLR); + state->trcvdctlr = readl(drvdata->base + TRCVDCTLR); + state->trcvdsacctlr = readl(drvdata->base + TRCVDSACCTLR); + state->trcvdarcctlr = readl(drvdata->base + TRCVDARCCTLR); + + for (i = 0; i < drvdata->nrseqstate; i++) + state->trcseqevr[i] = readl(drvdata->base + TRCSEQEVRn(i)); + + state->trcseqrstevr = readl(drvdata->base + TRCSEQRSTEVR); + state->trcseqstr = readl(drvdata->base + TRCSEQSTR); + state->trcextinselr = readl(drvdata->base + TRCEXTINSELR); + + for (i = 0; i < drvdata->nr_cntr; i++) { + state->trccntrldvr[i] = readl(drvdata->base + TRCCNTRLDVRn(i)); + state->trccntctlr[i] = readl(drvdata->base + TRCCNTCTLRn(i)); + state->trccntvr[i] = readl(drvdata->base + TRCCNTVRn(i)); + } + + for (i = 0; i < drvdata->nr_resource * 2; i++) + state->trcrsctlr[i] = readl(drvdata->base + TRCRSCTLRn(i)); + + for (i = 0; i < drvdata->nr_ss_cmp; i++) { + state->trcssccr[i] = readl(drvdata->base + TRCSSCCRn(i)); + state->trcsscsr[i] = readl(drvdata->base + TRCSSCSRn(i)); + state->trcsspcicr[i] = readl(drvdata->base + TRCSSPCICRn(i)); + } + + for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) { + state->trcacvr[i] = readl(drvdata->base + TRCACVRn(i)); + state->trcacatr[i] = readl(drvdata->base + TRCACATRn(i)); + } + + /* + * Data trace stream is architecturally prohibited for A profile cores + * so we don't save (or later restore) trcdvcvr and trcdvcmr - As per + * section 1.3.4 ("Possible functional configurations of an ETMv4 trace + * unit") of ARM IHI 0064D. + */ + + for (i = 0; i < drvdata->numcidc; i++) + state->trccidcvr[i] = readl(drvdata->base + TRCCIDCVRn(i)); + + for (i = 0; i < drvdata->numvmidc; i++) + state->trcvmidcvr[i] = readl(drvdata->base + TRCVMIDCVRn(i)); + + state->trccidcctlr0 = readl(drvdata->base + TRCCIDCCTLR0); + state->trccidcctlr1 = readl(drvdata->base + TRCCIDCCTLR1); + + state->trcvmidcctlr0 = readl(drvdata->base + TRCVMIDCCTLR0); + state->trcvmidcctlr0 = readl(drvdata->base + TRCVMIDCCTLR1); + + state->trcclaimset = readl(drvdata->base + TRCCLAIMCLR); + + state->trcpdcr = readl(drvdata->base + TRCPDCR); + + /* wait for TRCSTATR.IDLE to go up */ + if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) { + dev_err(etm_dev, + "timeout while waiting for Idle Trace Status\n"); + etm4_os_unlock(drvdata); + ret = -EBUSY; + goto out; + } + + drvdata->state_needs_restore = true; + + /* + * Power can be removed from the trace unit now. We do this to + * potentially save power on systems that respect the TRCPDCR_PU + * despite requesting software to save/restore state. + */ + writel_relaxed((state->trcpdcr & ~TRCPDCR_PU), + drvdata->base + TRCPDCR); + +out: + CS_LOCK(drvdata->base); + return ret; +} + +static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) +{ + int i; + struct etmv4_save_state *state = drvdata->save_state; + + CS_UNLOCK(drvdata->base); + + writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET); + + writel_relaxed(state->trcprgctlr, drvdata->base + TRCPRGCTLR); + writel_relaxed(state->trcprocselr, drvdata->base + TRCPROCSELR); + writel_relaxed(state->trcconfigr, drvdata->base + TRCCONFIGR); + writel_relaxed(state->trcauxctlr, drvdata->base + TRCAUXCTLR); + writel_relaxed(state->trceventctl0r, drvdata->base + TRCEVENTCTL0R); + writel_relaxed(state->trceventctl1r, drvdata->base + TRCEVENTCTL1R); + writel_relaxed(state->trcstallctlr, drvdata->base + TRCSTALLCTLR); + writel_relaxed(state->trctsctlr, drvdata->base + TRCTSCTLR); + writel_relaxed(state->trcsyncpr, drvdata->base + TRCSYNCPR); + writel_relaxed(state->trcccctlr, drvdata->base + TRCCCCTLR); + writel_relaxed(state->trcbbctlr, drvdata->base + TRCBBCTLR); + writel_relaxed(state->trctraceidr, drvdata->base + TRCTRACEIDR); + writel_relaxed(state->trcqctlr, drvdata->base + TRCQCTLR); + + writel_relaxed(state->trcvictlr, drvdata->base + TRCVICTLR); + writel_relaxed(state->trcviiectlr, drvdata->base + TRCVIIECTLR); + writel_relaxed(state->trcvissctlr, drvdata->base + TRCVISSCTLR); + writel_relaxed(state->trcvipcssctlr, drvdata->base + TRCVIPCSSCTLR); + writel_relaxed(state->trcvdctlr, drvdata->base + TRCVDCTLR); + writel_relaxed(state->trcvdsacctlr, drvdata->base + TRCVDSACCTLR); + writel_relaxed(state->trcvdarcctlr, drvdata->base + TRCVDARCCTLR); + + for (i = 0; i < drvdata->nrseqstate; i++) + writel_relaxed(state->trcseqevr[i], + drvdata->base + TRCSEQEVRn(i)); + + writel_relaxed(state->trcseqrstevr, drvdata->base + TRCSEQRSTEVR); + writel_relaxed(state->trcseqstr, drvdata->base + TRCSEQSTR); + writel_relaxed(state->trcextinselr, drvdata->base + TRCEXTINSELR); + + for (i = 0; i < drvdata->nr_cntr; i++) { + writel_relaxed(state->trccntrldvr[i], + drvdata->base + TRCCNTRLDVRn(i)); + writel_relaxed(state->trccntctlr[i], + drvdata->base + TRCCNTCTLRn(i)); + writel_relaxed(state->trccntvr[i], + drvdata->base + TRCCNTVRn(i)); + } + + for (i = 0; i < drvdata->nr_resource * 2; i++) + writel_relaxed(state->trcrsctlr[i], + drvdata->base + TRCRSCTLRn(i)); + + for (i = 0; i < drvdata->nr_ss_cmp; i++) { + writel_relaxed(state->trcssccr[i], + drvdata->base + TRCSSCCRn(i)); + writel_relaxed(state->trcsscsr[i], + drvdata->base + TRCSSCSRn(i)); + writel_relaxed(state->trcsspcicr[i], + drvdata->base + TRCSSPCICRn(i)); + } + + for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) { + writel_relaxed(state->trcacvr[i], + drvdata->base + TRCACVRn(i)); + writel_relaxed(state->trcacatr[i], + drvdata->base + TRCACATRn(i)); + } + + for (i = 0; i < drvdata->numcidc; i++) + writel_relaxed(state->trccidcvr[i], + drvdata->base + TRCCIDCVRn(i)); + + for (i = 0; i < drvdata->numvmidc; i++) + writel_relaxed(state->trcvmidcvr[i], + drvdata->base + TRCVMIDCVRn(i)); + + writel_relaxed(state->trccidcctlr0, drvdata->base + TRCCIDCCTLR0); + writel_relaxed(state->trccidcctlr1, drvdata->base + TRCCIDCCTLR1); + + writel_relaxed(state->trcvmidcctlr0, drvdata->base + TRCVMIDCCTLR0); + writel_relaxed(state->trcvmidcctlr0, drvdata->base + TRCVMIDCCTLR1); + + writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET); + + writel_relaxed(state->trcpdcr, drvdata->base + TRCPDCR); + + drvdata->state_needs_restore = false; + + /* + * As recommended by section 4.3.7 ("Synchronization when using the + * memory-mapped interface") of ARM IHI 0064D + */ + dsb(sy); + isb(); + + /* Unlock the OS lock to re-enable trace and external debug access */ + etm4_os_unlock(drvdata); + CS_LOCK(drvdata->base); +} + +static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, + void *v) +{ + struct etmv4_drvdata *drvdata; + unsigned int cpu = smp_processor_id(); + + if (!etmdrvdata[cpu]) + return 0; + + 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; + break; + case CPU_PM_EXIT: + case CPU_PM_ENTER_FAILED: + /* trcclaimset is set when there is state to restore */ + if (drvdata->state_needs_restore) + etm4_cpu_restore(drvdata); + break; + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + +static struct notifier_block etm4_cpu_pm_nb = { + .notifier_call = etm4_cpu_pm_notify, +}; + +static int etm4_cpu_pm_register(void) +{ + return cpu_pm_register_notifier(&etm4_cpu_pm_nb); +} + +static void etm4_cpu_pm_unregister(void) +{ + cpu_pm_unregister_notifier(&etm4_cpu_pm_nb); +} +#else +static int etm4_cpu_pm_register(void) { return 0; } +static void etm4_cpu_pm_unregister(void) { } +#endif + static int etm4_probe(struct amba_device *adev, const struct amba_id *id) { int ret; @@ -1101,6 +1402,17 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) dev_set_drvdata(dev, drvdata); + if (pm_save_enable == PARAM_PM_SAVE_FIRMWARE) + pm_save_enable = coresight_loses_context_with_cpu(dev) ? + PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER; + + if (pm_save_enable != PARAM_PM_SAVE_NEVER) { + drvdata->save_state = devm_kmalloc(dev, + sizeof(struct etmv4_save_state), GFP_KERNEL); + if (!drvdata->save_state) + return -ENOMEM; + } + /* Validity for the resource is already checked by the AMBA core */ base = devm_ioremap_resource(dev, res); if (IS_ERR(base)) @@ -1135,6 +1447,10 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) if (ret < 0) goto err_arch_supported; hp_online = ret; + + ret = etm4_cpu_pm_register(); + if (ret) + goto err_arch_supported; } cpus_read_unlock(); @@ -1185,6 +1501,8 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) err_arch_supported: if (--etm4_count == 0) { + etm4_cpu_pm_unregister(); + cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING); if (hp_online) cpuhp_remove_state_nocalls(hp_online); diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index 4523f10ddd0f..546d790cb01b 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -175,6 +175,7 @@ ETM_MODE_EXCL_USER) #define TRCSTATR_IDLE_BIT 0 +#define TRCSTATR_PMSTABLE_BIT 1 #define ETM_DEFAULT_ADDR_COMP 0 /* PowerDown Control Register bits */ @@ -281,6 +282,65 @@ struct etmv4_config { u32 ext_inp; }; +/** + * struct etm4_save_state - state to be preserved when ETM is without power + */ +struct etmv4_save_state { + u32 trcprgctlr; + u32 trcprocselr; + u32 trcconfigr; + u32 trcauxctlr; + u32 trceventctl0r; + u32 trceventctl1r; + u32 trcstallctlr; + u32 trctsctlr; + u32 trcsyncpr; + u32 trcccctlr; + u32 trcbbctlr; + u32 trctraceidr; + u32 trcqctlr; + + u32 trcvictlr; + u32 trcviiectlr; + u32 trcvissctlr; + u32 trcvipcssctlr; + u32 trcvdctlr; + u32 trcvdsacctlr; + u32 trcvdarcctlr; + + u32 trcseqevr[ETM_MAX_SEQ_STATES]; + u32 trcseqrstevr; + u32 trcseqstr; + u32 trcextinselr; + u32 trccntrldvr[ETMv4_MAX_CNTR]; + u32 trccntctlr[ETMv4_MAX_CNTR]; + u32 trccntvr[ETMv4_MAX_CNTR]; + + u32 trcrsctlr[ETM_MAX_RES_SEL * 2]; + + u32 trcssccr[ETM_MAX_SS_CMP]; + u32 trcsscsr[ETM_MAX_SS_CMP]; + u32 trcsspcicr[ETM_MAX_SS_CMP]; + + u64 trcacvr[ETM_MAX_SINGLE_ADDR_CMP]; + u64 trcacatr[ETM_MAX_SINGLE_ADDR_CMP]; + u64 trccidcvr[ETMv4_MAX_CTXID_CMP]; + u32 trcvmidcvr[ETM_MAX_VMID_CMP]; + u32 trccidcctlr0; + u32 trccidcctlr1; + u32 trcvmidcctlr0; + u32 trcvmidcctlr1; + + u32 trcclaimset; + + u32 cntr_val[ETMv4_MAX_CNTR]; + u32 seq_state; + u32 vinst_ctrl; + u32 ss_status[ETM_MAX_SS_CMP]; + + u32 trcpdcr; +}; + /** * struct etm4_drvdata - specifics associated to an ETM component * @base: Memory mapped base address for this component. @@ -336,6 +396,8 @@ struct etmv4_config { * @atbtrig: If the implementation can support ATB triggers * @lpoverride: If the implementation can support low-power state over. * @config: structure holding configuration parameters. + * @save_state: State to be preserved across power loss + * @state_needs_restore: True when there is context to restore after PM exit */ struct etmv4_drvdata { void __iomem *base; @@ -381,6 +443,8 @@ struct etmv4_drvdata { bool atbtrig; bool lpoverride; struct etmv4_config config; + struct etmv4_save_state *save_state; + bool state_needs_restore; }; /* Address comparator access types */ diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index 6453c67a4d01..e6ca899fea4e 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -1308,6 +1308,12 @@ static inline int coresight_search_device_idx(struct coresight_dev_list *dict, return -ENOENT; } +bool coresight_loses_context_with_cpu(struct device *dev) +{ + return fwnode_property_present(dev_fwnode(dev), + "arm,coresight-loses-context-with-cpu"); +} + /* * coresight_alloc_device_name - Get an index for a given device in the * device index list specific to a driver. An index is allocated for a diff --git a/include/linux/coresight.h b/include/linux/coresight.h index a2b68823717b..44e552de419c 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -285,6 +285,8 @@ extern void coresight_disclaim_device(void __iomem *base); extern void coresight_disclaim_device_unlocked(void __iomem *base); extern char *coresight_alloc_device_name(struct coresight_dev_list *devs, struct device *dev); + +extern bool coresight_loses_context_with_cpu(struct device *dev); #else static inline struct coresight_device * coresight_register(struct coresight_desc *desc) { return NULL; } @@ -307,6 +309,10 @@ static inline int coresight_claim_device(void __iomem *base) static inline void coresight_disclaim_device(void __iomem *base) {} static inline void coresight_disclaim_device_unlocked(void __iomem *base) {} +static inline bool coresight_loses_context_with_cpu(struct device *dev) +{ + return false; +} #endif extern int coresight_get_cpu(struct device *dev); From patchwork Fri Aug 16 15:46:14 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 11097895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CA36E1398 for ; Fri, 16 Aug 2019 15:46:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B55AE28640 for ; Fri, 16 Aug 2019 15:46:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A6F99287ED; Fri, 16 Aug 2019 15:46:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 5154D28640 for ; 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Fri, 16 Aug 2019 15:46:57 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeQs-0001qJ-Dp for linux-arm-kernel@lists.infradead.org; Fri, 16 Aug 2019 15:46:27 +0000 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 C98AF344; Fri, 16 Aug 2019 08:46:25 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1D71D3F694; Fri, 16 Aug 2019 08:46:23 -0700 (PDT) From: Andrew Murray To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin Subject: [PATCH v5 2/3] dt-bindings: arm: coresight: Add support for coresight-loses-context-with-cpu Date: Fri, 16 Aug 2019 16:46:14 +0100 Message-Id: <20190816154615.39854-3-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190816154615.39854-1-andrew.murray@arm.com> References: <20190816154615.39854-1-andrew.murray@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190816_084626_568932_D5D2D7D2 X-CRM114-Status: GOOD ( 10.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Al.Grant@arm.com, coresight@lists.linaro.org, Leo Yan , Sudeep Holla , linux-arm-kernel@lists.infradead.org, Mike Leach Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some coresight components, because of choices made during hardware integration, require their state to be saved and restored across CPU low power states. The software has no reliable method of detecting when save/restore is required thus let's add a binding to inform the kernel. Signed-off-by: Andrew Murray Reviewed-by: Mathieu Poirier Reviewed-by: Suzuki K Poulose --- Documentation/devicetree/bindings/arm/coresight.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/coresight.txt b/Documentation/devicetree/bindings/arm/coresight.txt index fcc3bacfd8bc..d02c42d21f2f 100644 --- a/Documentation/devicetree/bindings/arm/coresight.txt +++ b/Documentation/devicetree/bindings/arm/coresight.txt @@ -87,6 +87,15 @@ its hardware characteristcs. * port or ports: see "Graph bindings for Coresight" below. +* Optional properties for all components: + + * arm,coresight-loses-context-with-cpu : boolean. Indicates that the + hardware will lose register context on CPU power down (e.g. CPUIdle). + An example of where this may be needed are systems which contain a + coresight component and CPU in the same power domain. When the CPU + powers down the coresight component also powers down and loses its + context. This property is currently only used for the ETM 4.x driver. + * Optional properties for ETM/PTMs: * arm,cp14: must be present if the system accesses ETM/PTM management From patchwork Fri Aug 16 15:46:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Murray X-Patchwork-Id: 11097897 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6CF261398 for ; Fri, 16 Aug 2019 15:47:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5928F28640 for ; Fri, 16 Aug 2019 15:47:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4D34E287ED; Fri, 16 Aug 2019 15:47:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C16BE28640 for ; Fri, 16 Aug 2019 15:47:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=QURufTeNiZYJ7doMxQeXtmBsGNB3P4+mJPJtVE1Yvi0=; b=k62fDkezUj9se5 R4l0FLgtvaNTEgNNGo1kAzayJS0aBqtVOhbn8wtNSZH9AcraE4tbI/k27xp5TuzKpzE64m57aPZue 3PzltqJpRR6ff48AMMZZZMySUwjVwF10BBl5LAuLBUAzBgVocMFnH4CA/oNhStaz8k0FNRnO43RlX ePmEP6HEAMzX+lA13Pogt9TrkQ73PFwjpzRI9qpDeD4AdfA6pYIJtFCxIkPNIqZsylzl8pZB6RPH5 J0qa3Ylqp/2EEyclW/aVn/tj/d+wkcK+G6djoZIvLIYIkFp3uMXL84ZmU9PE67MKVHcAVdfQCzDGo 4oVsJzlvQnNqkMzhrc2A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeRf-0002fz-6c; Fri, 16 Aug 2019 15:47:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hyeQv-0001zS-7Z for linux-arm-kernel@lists.infradead.org; Fri, 16 Aug 2019 15:46:30 +0000 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 CAFF9360; Fri, 16 Aug 2019 08:46:27 -0700 (PDT) Received: from e119886-lin.cambridge.arm.com (unknown [10.37.6.20]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1F7353F694; Fri, 16 Aug 2019 08:46:25 -0700 (PDT) From: Andrew Murray To: Mathieu Poirier , Suzuki K Poulose , Alexander Shishkin Subject: [PATCH v5 3/3] coresight: etm4x: save/restore state for external agents Date: Fri, 16 Aug 2019 16:46:15 +0100 Message-Id: <20190816154615.39854-4-andrew.murray@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190816154615.39854-1-andrew.murray@arm.com> References: <20190816154615.39854-1-andrew.murray@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190816_084629_437552_D00DCCEF X-CRM114-Status: GOOD ( 16.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Al.Grant@arm.com, coresight@lists.linaro.org, Leo Yan , Sudeep Holla , linux-arm-kernel@lists.infradead.org, Mike Leach Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Some hardware will ignore bit TRCPDCR.PU which is used to signal to hardware that power should not be removed from the trace unit. Much like self-hosted debug, we should also save/restore the trace unit state when it is in use by external agents. We wish to avoid saving the hardware state when coresight isn't in use to reduce PM latency - However as external trace/debug is designed to be unintrusive to the CPU, the only way of determining that an external agent is present is to read the claim tags (TRCCLAIMCLR). Unfortunately this register needs power and clocking - something it won't have when coresight isn't in use. We also don't want to temporarily enable it due to the latency and PM context. Let's compromise by adding a module parameter that will keep the trace unit powered and clocked, thus allowing us to only save/restore state when external trace (or self-hosted) is in use. Though please note that this doesn't allow for tracing from boot on hardware that needs save/restore as the CPU may idle prior to the ETMv4 driver starting and adding PM hooks to save/restore. Signed-off-by: Andrew Murray --- drivers/hwtracing/coresight/coresight-etm4x.c | 27 ++++++++++++++++--- drivers/hwtracing/coresight/coresight.c | 2 +- include/linux/coresight.h | 7 +++++ 3 files changed, 31 insertions(+), 5 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 35a524eec36d..c5d527f7cbd5 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -42,11 +42,12 @@ MODULE_PARM_DESC(boot_enable, "Enable tracing on boot"); #define PARAM_PM_SAVE_FIRMWARE 0 /* save self-hosted state as per firmware */ #define PARAM_PM_SAVE_NEVER 1 /* never save any state */ #define PARAM_PM_SAVE_SELF_HOSTED 2 /* save self-hosted state only */ +#define PARAM_PM_SAVE_EXTERNAL 3 /* save all state (keeps power on) */ static int pm_save_enable = PARAM_PM_SAVE_FIRMWARE; module_param(pm_save_enable, int, 0444); MODULE_PARM_DESC(pm_save_enable, - "Save/restore state on power down: 1 = never, 2 = self-hosted"); + "Save/restore state on power down: 1 = never, 2 = self-hosted, 3 = self-hosted/external"); /* The number of ETMv4 currently registered */ static int etm4_count; @@ -1331,6 +1332,22 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) CS_LOCK(drvdata->base); } +static bool etm4_coresight_in_use(struct etmv4_drvdata *drvdata) +{ + /* Self-hosted session in progress? */ + if (local_read(&drvdata->mode)) + return true; + + /* External agents can be detected through claim tags however we + * only read these tags if the trace unit is powered. + */ + if (drvdata->csdev && pm_runtime_active(drvdata->csdev->dev.parent)) + if (coresight_is_claimed_any(drvdata->base)) + return true; + + return false; +} + static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, void *v) { @@ -1350,8 +1367,8 @@ static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd, switch (cmd) { case CPU_PM_ENTER: - /* save the state if self-hosted coresight is in use */ - if (local_read(&drvdata->mode)) + /* Save the state if coresight is in use */ + if (etm4_coresight_in_use(drvdata)) if (etm4_cpu_save(drvdata)) return NOTIFY_BAD; break; @@ -1488,7 +1505,9 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id) goto err_arch_supported; } - pm_runtime_put(&adev->dev); + if (pm_save_enable != PARAM_PM_SAVE_EXTERNAL) + pm_runtime_put(&adev->dev); + dev_info(&drvdata->csdev->dev, "CPU%d: ETM v%d.%d initialized\n", drvdata->cpu, drvdata->arch >> 4, drvdata->arch & 0xf); diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c index e6ca899fea4e..474b7372864e 100644 --- a/drivers/hwtracing/coresight/coresight.c +++ b/drivers/hwtracing/coresight/coresight.c @@ -140,7 +140,7 @@ static inline bool coresight_is_claimed_self_hosted(void __iomem *base) return coresight_read_claim_tags(base) == CORESIGHT_CLAIM_SELF_HOSTED; } -static inline bool coresight_is_claimed_any(void __iomem *base) +bool coresight_is_claimed_any(void __iomem *base) { return coresight_read_claim_tags(base) != 0; } diff --git a/include/linux/coresight.h b/include/linux/coresight.h index 44e552de419c..65bfd2cb0283 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -286,6 +286,8 @@ extern void coresight_disclaim_device_unlocked(void __iomem *base); extern char *coresight_alloc_device_name(struct coresight_dev_list *devs, struct device *dev); +extern bool coresight_is_claimed_any(void __iomem *base); + extern bool coresight_loses_context_with_cpu(struct device *dev); #else static inline struct coresight_device * @@ -309,6 +311,11 @@ static inline int coresight_claim_device(void __iomem *base) static inline void coresight_disclaim_device(void __iomem *base) {} static inline void coresight_disclaim_device_unlocked(void __iomem *base) {} +static inline bool coresight_is_claimed_any(void __iomem *base) +{ + return false; +} + static inline bool coresight_loses_context_with_cpu(struct device *dev) { return false;