From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
mathieu.poirier@linaro.org, anshuman.khandual@arm.com,
coresight@lists.linaro.org,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-kernel@vger.kernel.org,
Tingwei Zhang <tingwei@codeaurora.org>,
leo.yan@linaro.org, mike.leach@linaro.org
Subject: [PATCH v6 02/26] coresight: etm4x: Skip accessing TRCPDCR in save/restore
Date: Thu, 7 Jan 2021 12:38:35 +0000 [thread overview]
Message-ID: <20210107123859.674252-3-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20210107123859.674252-1-suzuki.poulose@arm.com>
When the ETM is affected by Qualcomm errata, modifying the
TRCPDCR could cause the system hang. Even though this is
taken care of during enable/disable ETM, the ETM state
save/restore could still access the TRCPDCR. Make sure
we skip the access during the save/restore.
Found by code inspection.
Fixes: 02510a5aa78df45 ("coresight: etm4x: Add support to skip trace unit power up")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Cc: Tingwei Zhang <tingwei@codeaurora.org>
Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 76526679b998..cce65fc0c9aa 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1373,7 +1373,8 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
state->trcclaimset = readl(drvdata->base + TRCCLAIMCLR);
- state->trcpdcr = readl(drvdata->base + TRCPDCR);
+ if (!drvdata->skip_power_up)
+ state->trcpdcr = readl(drvdata->base + TRCPDCR);
/* wait for TRCSTATR.IDLE to go up */
if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) {
@@ -1391,9 +1392,9 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
* 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);
-
+ if (!drvdata->skip_power_up)
+ writel_relaxed((state->trcpdcr & ~TRCPDCR_PU),
+ drvdata->base + TRCPDCR);
out:
CS_LOCK(drvdata->base);
return ret;
@@ -1488,7 +1489,8 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET);
- writel_relaxed(state->trcpdcr, drvdata->base + TRCPDCR);
+ if (!drvdata->skip_power_up)
+ writel_relaxed(state->trcpdcr, drvdata->base + TRCPDCR);
drvdata->state_needs_restore = false;
--
2.24.1
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next prev parent reply other threads:[~2021-01-07 12:41 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-07 12:38 [PATCH v6 00/26] coresight: etm4x: Support for system instructions Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 01/26] coresight: etm4x: Handle access to TRCSSPCICRn Suzuki K Poulose
2021-01-07 12:38 ` Suzuki K Poulose [this message]
2021-01-07 12:38 ` [PATCH v6 03/26] coresight: Introduce device access abstraction Suzuki K Poulose
2021-01-07 23:38 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 04/26] coresight: tpiu: Prepare for using coresight " Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 05/26] coresight: Convert coresight_timeout to use " Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 06/26] coresight: Convert claim/disclaim operations to use access wrappers Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 07/26] coresight: etm4x: Always read the registers on the host CPU Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 08/26] coresight: etm4x: Convert all register accesses Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 09/26] coresight: etm4x: Add commentary on the registers Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 10/26] coresight: etm4x: Add sysreg access helpers Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 11/26] coresight: etm4x: Define DEVARCH register fields Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 12/26] coresight: etm4x: Check for Software Lock Suzuki K Poulose
2021-01-08 0:18 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 13/26] coresight: etm4x: Cleanup secure exception level masks Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 14/26] coresight: etm4x: Clean up " Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 15/26] coresight: etm4x: Handle ETM architecture version Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 16/26] coresight: etm4x: Detect access early on the target CPU Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 17/26] coresight: etm4x: Use TRCDEVARCH for component discovery Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 18/26] coresight: etm4x: Expose trcdevarch via sysfs Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 19/26] coresight: etm4x: Add necessary synchronization for sysreg access Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 20/26] coresight: etm4x: Detect system instructions support Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 21/26] coresight: etm4x: Refactor probing routine Suzuki K Poulose
2021-01-08 0:38 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 22/26] coresight: etm4x: Run arch feature detection on the CPU Suzuki K Poulose
2021-01-08 0:49 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 23/26] coresight: etm4x: Add support for sysreg only devices Suzuki K Poulose
2021-01-08 0:55 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 24/26] dts: bindings: coresight: ETM system register access only units Suzuki K Poulose
2021-01-07 12:38 ` [PATCH v6 25/26] arm64: Add TRFCR_ELx definitions Suzuki K Poulose
2021-01-08 1:01 ` Mathieu Poirier
2021-01-07 12:38 ` [PATCH v6 26/26] coresight: Add support for v8.4 SelfHosted tracing Suzuki K Poulose
2021-01-08 1:02 ` Mathieu Poirier
2021-01-08 1:09 ` [PATCH v6 00/26] coresight: etm4x: Support for system instructions Mathieu Poirier
2021-01-08 9:08 ` Suzuki K Poulose
2021-01-08 14:15 ` Suzuki K Poulose
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