From: Leo Yan <leo.yan@linaro.org>
To: Mathieu Poirier <mathieu.poirier@linaro.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Mike Leach <mike.leach@linaro.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
James Clark <james.clark@arm.com>,
coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: Leo Yan <leo.yan@linaro.org>
Subject: [PATCH v1 1/4] coresight: etm4x: Add lock for reading virtual context ID comparator
Date: Sun, 31 Oct 2021 22:42:11 +0800 [thread overview]
Message-ID: <20211031144214.237879-2-leo.yan@linaro.org> (raw)
In-Reply-To: <20211031144214.237879-1-leo.yan@linaro.org>
When read the virtual context ID comparator value via sysfs node, the
driver firstly reads out the index, then reads the comparator value
based on index.
This patch adds the spinlock to protect the atomicity for up two steps.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index a0640fa5c55b..e4c8c44d04ef 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -2111,7 +2111,9 @@ static ssize_t vmid_val_show(struct device *dev,
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
struct etmv4_config *config = &drvdata->config;
+ spin_lock(&drvdata->spinlock);
val = (unsigned long)config->vmid_val[config->vmid_idx];
+ spin_unlock(&drvdata->spinlock);
return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
}
--
2.25.1
next prev parent reply other threads:[~2021-10-31 14:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-31 14:42 [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace Leo Yan
2021-10-31 14:42 ` Leo Yan [this message]
2021-11-01 9:49 ` [PATCH v1 1/4] coresight: etm4x: Add lock for reading virtual context ID comparator Suzuki K Poulose
2021-11-01 10:59 ` Leo Yan
2021-10-31 14:42 ` [PATCH v1 2/4] coresight: etm4x: Don't use virtual contextID for non-root PID namespace Leo Yan
2021-11-04 15:07 ` Suzuki K Poulose
2021-11-04 15:24 ` Leo Yan
2021-10-31 14:42 ` [PATCH v1 3/4] coresight: etm4x: Don't trace contextID for non-root namespace in perf mode Leo Yan
2021-11-16 9:46 ` Suzuki K Poulose
2021-11-17 13:53 ` Leo Yan
2021-10-31 14:42 ` [PATCH v1 4/4] coresight: etm3x: " Leo Yan
2021-11-16 13:52 ` [PATCH v1 0/4] coresight: etm: Correct (virtual) contextID tracing for namespace Suzuki K Poulose
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