From: Mathieu Poirier <mathieu.poirier@linaro.org> To: gregkh@linuxfoundation.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/28] coresight: always use stashed trace id value in etm4_trace_id Date: Thu, 25 Aug 2016 15:18:53 -0600 [thread overview] Message-ID: <1472159958-5981-4-git-send-email-mathieu.poirier@linaro.org> (raw) In-Reply-To: <1472159958-5981-1-git-send-email-mathieu.poirier@linaro.org> From: Sudeep Holla <sudeep.holla@arm.com> etm4_trace_id is not guaranteed to be executed on the CPU whose ETM is being accessed. This leads to exception similar to below one if the CPU whose ETM is being accessed is in deeper idle states. So it must be executed on the CPU whose ETM is being accessed. Unhandled fault: synchronous external abort (0x96000210) at 0xffff000008db4040 Internal error: : 96000210 [#1] PREEMPT SMP Modules linked in: CPU: 5 PID: 5979 Comm: etm.sh Not tainted 4.7.0-rc3 #159 Hardware name: ARM Juno development board (r2) (DT) task: ffff80096dd34b00 ti: ffff80096dfe4000 task.ti: ffff80096dfe4000 PC is at etm4_trace_id+0x5c/0x90 LR is at etm4_trace_id+0x3c/0x90 Call trace: etm4_trace_id+0x5c/0x90 coresight_id_match+0x78/0xa8 bus_for_each_dev+0x60/0xa0 coresight_enable+0xc0/0x1b8 enable_source_store+0x3c/0x70 dev_attr_store+0x18/0x28 sysfs_kf_write+0x48/0x58 kernfs_fop_write+0x14c/0x1e0 __vfs_write+0x1c/0x100 vfs_write+0xa0/0x1b8 SyS_write+0x44/0xa0 el0_svc_naked+0x24/0x28 However, TRCTRACEIDR is not guaranteed to hold the previous programmed trace id if it enters deeper idle states. Further, the trace id that is computed in etm4_init_trace_id is programmed into TRCTRACEIDR only in etm4_enable_hw which happens much later in the sequence after coresight_id_match is executed from enable_source_store. This patch simplifies etm4_trace_id by returning the stashed trace id value similar to etm4_cpu_id. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- drivers/hwtracing/coresight/coresight-etm4x.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 1a5e0d14c1dd..17e2e81d2e90 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -79,22 +79,8 @@ static int etm4_cpu_id(struct coresight_device *csdev) static int etm4_trace_id(struct coresight_device *csdev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - unsigned long flags; - int trace_id = -1; - if (!local_read(&drvdata->mode)) - return drvdata->trcid; - - spin_lock_irqsave(&drvdata->spinlock, flags); - - CS_UNLOCK(drvdata->base); - trace_id = readl_relaxed(drvdata->base + TRCTRACEIDR); - trace_id &= ETM_TRACEID_MASK; - CS_LOCK(drvdata->base); - - spin_unlock_irqrestore(&drvdata->spinlock, flags); - - return trace_id; + return drvdata->trcid; } static void etm4_enable_hw(void *info) -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: mathieu.poirier@linaro.org (Mathieu Poirier) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 03/28] coresight: always use stashed trace id value in etm4_trace_id Date: Thu, 25 Aug 2016 15:18:53 -0600 [thread overview] Message-ID: <1472159958-5981-4-git-send-email-mathieu.poirier@linaro.org> (raw) In-Reply-To: <1472159958-5981-1-git-send-email-mathieu.poirier@linaro.org> From: Sudeep Holla <sudeep.holla@arm.com> etm4_trace_id is not guaranteed to be executed on the CPU whose ETM is being accessed. This leads to exception similar to below one if the CPU whose ETM is being accessed is in deeper idle states. So it must be executed on the CPU whose ETM is being accessed. Unhandled fault: synchronous external abort (0x96000210) at 0xffff000008db4040 Internal error: : 96000210 [#1] PREEMPT SMP Modules linked in: CPU: 5 PID: 5979 Comm: etm.sh Not tainted 4.7.0-rc3 #159 Hardware name: ARM Juno development board (r2) (DT) task: ffff80096dd34b00 ti: ffff80096dfe4000 task.ti: ffff80096dfe4000 PC is at etm4_trace_id+0x5c/0x90 LR is at etm4_trace_id+0x3c/0x90 Call trace: etm4_trace_id+0x5c/0x90 coresight_id_match+0x78/0xa8 bus_for_each_dev+0x60/0xa0 coresight_enable+0xc0/0x1b8 enable_source_store+0x3c/0x70 dev_attr_store+0x18/0x28 sysfs_kf_write+0x48/0x58 kernfs_fop_write+0x14c/0x1e0 __vfs_write+0x1c/0x100 vfs_write+0xa0/0x1b8 SyS_write+0x44/0xa0 el0_svc_naked+0x24/0x28 However, TRCTRACEIDR is not guaranteed to hold the previous programmed trace id if it enters deeper idle states. Further, the trace id that is computed in etm4_init_trace_id is programmed into TRCTRACEIDR only in etm4_enable_hw which happens much later in the sequence after coresight_id_match is executed from enable_source_store. This patch simplifies etm4_trace_id by returning the stashed trace id value similar to etm4_cpu_id. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> --- drivers/hwtracing/coresight/coresight-etm4x.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 1a5e0d14c1dd..17e2e81d2e90 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -79,22 +79,8 @@ static int etm4_cpu_id(struct coresight_device *csdev) static int etm4_trace_id(struct coresight_device *csdev) { struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - unsigned long flags; - int trace_id = -1; - if (!local_read(&drvdata->mode)) - return drvdata->trcid; - - spin_lock_irqsave(&drvdata->spinlock, flags); - - CS_UNLOCK(drvdata->base); - trace_id = readl_relaxed(drvdata->base + TRCTRACEIDR); - trace_id &= ETM_TRACEID_MASK; - CS_LOCK(drvdata->base); - - spin_unlock_irqrestore(&drvdata->spinlock, flags); - - return trace_id; + return drvdata->trcid; } static void etm4_enable_hw(void *info) -- 2.7.4
next prev parent reply other threads:[~2016-08-25 21:26 UTC|newest] Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-08-25 21:18 [PATCH 00/28] coresight: next v4.8-rc3 Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 01/28] coresight: access conn->child_name only if it's initialised Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 02/28] coresight-stm: support mmapping channel regions with mmio_addr Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier [this message] 2016-08-25 21:18 ` [PATCH 03/28] coresight: always use stashed trace id value in etm4_trace_id Mathieu Poirier 2016-08-25 21:18 ` [PATCH 04/28] coresight: Remove erroneous dma_free_coherent in tmc_probe Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 05/28] coresight: Consolidate error handling path for tmc_probe Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 06/28] coresight: Fix csdev connections initialisation Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 07/28] coresight: tmc: Limit the trace to available data Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 08/28] coresight: etmv4: Fix ETMv4x peripheral ID table Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:18 ` [PATCH 09/28] coresight: Cleanup TMC status check Mathieu Poirier 2016-08-25 21:18 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 10/28] coresight: Add better messages for coresight_timeout Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 11/28] coresight: delay initialisation when children are missing Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 12/28] coresight: add PM runtime calls to coresight_simple_func() Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 13/28] coresight-etm3x: Add ARM ETM 3.5 Cortex-A5 peripheral ID Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 14/28] hwtracing: coresight: of_coresight: add missing of_node_put after calling of_parse_phandle Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 15/28] coresight: Use local coresight_desc instances Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 16/28] coresight: etm4x: remove duplicated include from coresight-etm4x.c Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 17/28] coresight: tmc: Delete an unnecessary check before the function call "kfree" Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 18/28] coresight: etm4x: request to retain power to the trace unit when active Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 19/28] coresight: fix handling of ETM trace register access via sysfs Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 20/28] coresight: etm-perf: pass struct perf_event to source::enable/disable() Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 21/28] coresight: remove duplicated enumeration Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 22/28] coresight: etm-perf: configuring filters from perf core Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 23/28] coresight: etm4x: split default and filter configuration Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 24/28] coresight: etm4x: cleaning up default " Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 25/28] coresight: etm4x: adding range filter configuration function Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 26/28] coresight: etm4x: configuring include/exclude function Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 27/28] coresight: etm4x: adding configurable address range filtering Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-25 21:19 ` [PATCH 28/28] coresight: etm4x: adding configurable start/stop filtering Mathieu Poirier 2016-08-25 21:19 ` Mathieu Poirier 2016-08-31 11:08 ` [PATCH 00/28] coresight: next v4.8-rc3 Greg KH 2016-08-31 11:08 ` Greg KH
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