From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="fTlEJ7Cp" Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFFF610E3; Fri, 8 Dec 2023 09:25:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702056351; x=1733592351; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=KmdBc3HWqTwUasM7vZjbBzM2mrzmquHQNOkk6b78KiY=; b=fTlEJ7CpPbxGXy9gUyjriiXVFqrH35Mx6lGLKRFEXFJzxb4hKRCh1e8x +aHm3N+hIawSiL5yC4VwhqSsr6Z9BW9d/FR4iXMUq26Ppsa0R+Zn8SfhN PlXOGhczzk/DhNc2NrtnOleLdH/lXFi9BZoRSyKZWUCuFD7A4uGF4jg7C yYMEVWdHx+Mek/HzkDWSvTcSvt4nG2lj4zNaATYKzR4gej1eOp1I2p413 fYSU+BnBSrn9cRPf0bUklnFJ+5ewMRk8RcWNTNskdwjMi2Txtg/E0In+f jITeAXzih4RABDheVCr/QFFDUbNIJhsBzWwB/miG75HvgsAnBymoT/L7c w==; X-IronPort-AV: E=McAfee;i="6600,9927,10918"; a="379432530" X-IronPort-AV: E=Sophos;i="6.04,261,1695711600"; d="scan'208";a="379432530" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2023 09:25:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10918"; a="772201694" X-IronPort-AV: E=Sophos;i="6.04,261,1695711600"; d="scan'208";a="772201694" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO ahunter-VirtualBox.home\044ger.corp.intel.com) ([10.249.34.218]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2023 09:25:27 -0800 From: Adrian Hunter To: Peter Zijlstra Cc: Ingo Molnar , Mark Rutland , Alexander Shishkin , Heiko Carstens , Thomas Richter , Hendrik Brueckner , Suzuki K Poulose , Mike Leach , James Clark , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, Yicong Yang , Jonathan Cameron , Will Deacon , Arnaldo Carvalho de Melo , Jiri Olsa , Namhyung Kim , Ian Rogers , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH RFC V2 4/4] coresight: Have a stab at support for pause / resume Date: Fri, 8 Dec 2023 19:24:49 +0200 Message-Id: <20231208172449.35444-5-adrian.hunter@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231208172449.35444-1-adrian.hunter@intel.com> References: <20231208172449.35444-1-adrian.hunter@intel.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Content-Transfer-Encoding: 8bit For discussion only, un-tested, not even compiled... Signed-off-by: Adrian Hunter --- .../hwtracing/coresight/coresight-etm-perf.c | 29 ++++++++++++++++--- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 5ca6278baff4..36e774405c51 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -45,6 +45,7 @@ static bool etm_perf_up; struct etm_ctxt { struct perf_output_handle handle; struct etm_event_data *event_data; + int pr_allowed; }; static DEFINE_PER_CPU(struct etm_ctxt, etm_ctxt); @@ -452,6 +453,13 @@ static void etm_event_start(struct perf_event *event, int flags) struct list_head *path; u64 hw_id; + if (mode & PERF_EF_RESUME) { + if (!READ_ONCE(ctxt->pr_allowed)) + return; + } else if (READ_ONCE(event->aux_paused)) { + goto out_pr_allowed; + } + if (!csdev) goto fail; @@ -514,6 +522,8 @@ static void etm_event_start(struct perf_event *event, int flags) event->hw.state = 0; /* Save the event_data for this ETM */ ctxt->event_data = event_data; +out_pr_allowed: + WRITE_ONCE(ctxt->pr_allowed, 1); return; fail_disable_path: @@ -530,6 +540,7 @@ static void etm_event_start(struct perf_event *event, int flags) } fail: event->hw.state = PERF_HES_STOPPED; + WRITE_ONCE(ctxt->pr_allowed, 0); return; } @@ -543,6 +554,11 @@ static void etm_event_stop(struct perf_event *event, int mode) struct etm_event_data *event_data; struct list_head *path; + if (mode & PERF_EF_PAUSE && !READ_ONCE(ctxt->pr_allowed)) + return; + + WRITE_ONCE(ctxt->pr_allowed, 0); + /* * If we still have access to the event_data via handle, * confirm that we haven't messed up the tracking. @@ -556,7 +572,7 @@ static void etm_event_stop(struct perf_event *event, int mode) ctxt->event_data = NULL; if (event->hw.state == PERF_HES_STOPPED) - return; + goto out_pr_allowed; /* We must have a valid event_data for a running event */ if (WARN_ON(!event_data)) @@ -627,6 +643,10 @@ static void etm_event_stop(struct perf_event *event, int mode) /* Disabling the path make its elements available to other sessions */ coresight_disable_path(path); + +out_pr_allowed: + if (mode & PERF_EF_PAUSE) + WRITE_ONCE(ctxt->pr_allowed, 1); } static int etm_event_add(struct perf_event *event, int mode) @@ -634,7 +654,7 @@ static int etm_event_add(struct perf_event *event, int mode) int ret = 0; struct hw_perf_event *hwc = &event->hw; - if (mode & PERF_EF_START) { + if (mode & PERF_EF_START && !READ_ONCE(event->aux_paused)) { etm_event_start(event, 0); if (hwc->state & PERF_HES_STOPPED) ret = -EINVAL; @@ -886,8 +906,9 @@ int __init etm_perf_init(void) { int ret; - etm_pmu.capabilities = (PERF_PMU_CAP_EXCLUSIVE | - PERF_PMU_CAP_ITRACE); + etm_pmu.capabilities = PERF_PMU_CAP_EXCLUSIVE | + PERF_PMU_CAP_ITRACE | + PERF_PMU_CAP_AUX_PAUSE; etm_pmu.attr_groups = etm_pmu_attr_groups; etm_pmu.task_ctx_nr = perf_sw_context; -- 2.34.1