From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: coresight@lists.linaro.org, mathieu.poirier@linaro.org,
anshuman.khandual@arm.com, mike.leach@linaro.org,
leo.yan@linaro.org, linux-kernel@vger.kernel.org,
jonathan.zhouwen@huawei.com, catalin.marinas@arm.com,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
Tingwei Zhang <tingwei@codeaurora.org>
Subject: [PATCH v7 02/28] coresight: etm4x: Skip accessing TRCPDCR in save/restore
Date: Sun, 10 Jan 2021 22:48:24 +0000 [thread overview]
Message-ID: <20210110224850.1880240-3-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20210110224850.1880240-1-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
next prev parent reply other threads:[~2021-01-10 22:50 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-10 22:48 [PATCH v7 00/28] coresight: etm4x: Support for system instructions Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 01/28] coresight: etm4x: Handle access to TRCSSPCICRn Suzuki K Poulose
2021-01-10 22:48 ` Suzuki K Poulose [this message]
2021-01-25 18:39 ` [PATCH v7 02/28] coresight: etm4x: Skip accessing TRCPDCR in save/restore Mathieu Poirier
2021-01-10 22:48 ` [PATCH v7 03/28] coresight: Introduce device access abstraction Suzuki K Poulose
2021-01-25 18:42 ` Mathieu Poirier
2021-01-10 22:48 ` [PATCH v7 04/28] coresight: tpiu: Prepare for using coresight " Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 05/28] coresight: Convert coresight_timeout to use " Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 06/28] coresight: Convert claim/disclaim operations to use access wrappers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 07/28] coresight: etm4x: Always read the registers on the host CPU Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 08/28] coresight: etm4x: Convert all register accesses Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 09/28] coresight: etm4x: Make offset available for sysfs attributes Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 10/28] coresight: etm4x: Add commentary on the registers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 11/28] coresight: etm4x: Add sysreg access helpers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 12/28] coresight: etm4x: Hide sysfs attributes for unavailable registers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 13/28] coresight: etm4x: Define DEVARCH register fields Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 14/28] coresight: etm4x: Check for Software Lock Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 15/28] coresight: etm4x: Cleanup secure exception level masks Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 16/28] coresight: etm4x: Clean up " Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 17/28] coresight: etm4x: Handle ETM architecture version Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 18/28] coresight: etm4x: Detect access early on the target CPU Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 19/28] coresight: etm4x: Use TRCDEVARCH for component discovery Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 20/28] coresight: etm4x: Expose trcdevarch via sysfs Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 21/28] coresight: etm4x: Add necessary synchronization for sysreg access Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 22/28] coresight: etm4x: Detect system instructions support Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 23/28] coresight: etm4x: Refactor probing routine Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 24/28] coresight: etm4x: Run arch feature detection on the CPU Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 25/28] coresight: etm4x: Add support for sysreg only devices Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 26/28] dts: bindings: coresight: ETM system register access only units Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 27/28] arm64: Add TRFCR_ELx definitions Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 28/28] coresight: Add support for v8.4 SelfHosted tracing Suzuki K Poulose
2021-02-12 10:34 ` Mike Leach
2021-02-12 15:36 ` Suzuki K Poulose
2021-02-12 17:30 ` Mike Leach
2021-02-18 14:51 ` Suzuki K Poulose
2021-01-25 18:49 ` [PATCH v7 00/28] coresight: etm4x: Support for system instructions Mathieu Poirier
2021-01-25 22:05 ` Suzuki K Poulose
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