From: Tingwei Zhang <tingwei@codeaurora•org>
To: Mathieu Poirier <mathieu.poirier@linaro•org>,
Suzuki K Poulose <suzuki.poulose@arm•com>,
Alexander Shishkin <alexander.shishkin@linux•intel.com>
Cc: tsoni@codeaurora•org,
Sai Prakash Ranjan <saiprakash.ranjan@codeaurora•org>,
Kim Phillips <kim.phillips@arm•com>,
Mao Jinlong <jinlmao@codeaurora•org>,
Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
coresight@lists•linaro.org, Randy Dunlap <rdunlap@infradead•org>,
Mian Yousaf Kaukab <ykaukab@suse•de>,
Russell King <linux@armlinux•org.uk>,
Tingwei Zhang <tingwei@codeaurora•org>,
Leo Yan <leo.yan@linaro•org>,
linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 19/20] coresight: add try_get_module() in coresight_grab_device()
Date: Fri, 17 Jul 2020 13:45:35 +0800 [thread overview]
Message-ID: <20200717054536.7052-20-tingwei@codeaurora.org> (raw)
In-Reply-To: <20200717054536.7052-1-tingwei@codeaurora.org>
When coresight device is in an active session, driver module of
that device should not be removed. Use try_get_module() in
coresight_grab_device() to prevent module to be unloaded.
Signed-off-by: Tingwei Zhang <tingwei@codeaurora•org>
---
drivers/hwtracing/coresight/coresight.c | 27 +++++++++++++++++++++----
1 file changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 55b699aca9ec..eabb59531c75 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -655,7 +655,7 @@ struct coresight_device *coresight_get_sink_by_id(u32 id)
* don't appear on the trace path, they should be handled along with the
* the master device.
*/
-static void coresight_grab_device(struct coresight_device *csdev)
+static int coresight_grab_device(struct coresight_device *csdev)
{
int i;
@@ -663,10 +663,25 @@ static void coresight_grab_device(struct coresight_device *csdev)
struct coresight_device *child;
child = csdev->pdata->conns[i].child_dev;
- if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
+ if (child && child->type == CORESIGHT_DEV_TYPE_HELPER) {
+ if (!try_module_get(child->dev.parent->driver->owner))
+ goto err;
pm_runtime_get_sync(child->dev.parent);
+ }
}
+ if (!try_module_get(csdev->dev.parent->driver->owner))
+ goto err;
pm_runtime_get_sync(csdev->dev.parent);
+ return 0;
+err:
+ for (i--; i >= 0; i--) {
+ struct coresight_device *child;
+
+ child = csdev->pdata->conns[i].child_dev;
+ if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
+ pm_runtime_put(child->dev.parent);
+ }
+ return -ENODEV;
}
/*
@@ -678,12 +693,15 @@ static void coresight_drop_device(struct coresight_device *csdev)
int i;
pm_runtime_put(csdev->dev.parent);
+ module_put(csdev->dev.parent->driver->owner);
for (i = 0; i < csdev->pdata->nr_outport; i++) {
struct coresight_device *child;
child = csdev->pdata->conns[i].child_dev;
- if (child && child->type == CORESIGHT_DEV_TYPE_HELPER)
+ if (child && child->type == CORESIGHT_DEV_TYPE_HELPER) {
pm_runtime_put(child->dev.parent);
+ module_put(child->dev.parent->driver->owner);
+ }
}
}
@@ -736,7 +754,8 @@ static int _coresight_build_path(struct coresight_device *csdev,
if (!node)
return -ENOMEM;
- coresight_grab_device(csdev);
+ if (coresight_grab_device(csdev))
+ return -ENODEV;
node->csdev = csdev;
list_add(&node->link, path);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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next prev parent reply other threads:[~2020-07-17 5:52 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 5:45 [PATCH v3 00/20] coresight: allow to build coresight as modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 01/20] coresight: cpu_debug: add module name in Kconfig Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 02/20] coresight: cpu_debug: define MODULE_DEVICE_TABLE Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 03/20] coresight: use IS_ENABLED for CONFIGs that may be modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 04/20] coresight: add coresight prefix to barrier_pkt Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 05/20] coresight: export global symbols Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 06/20] Allow to build coresight-stm as a module, for ease of development Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 07/20] coresight: allow etm3x to be built as a module Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 08/20] coresight: allow etm4x " Tingwei Zhang
2020-07-17 17:05 ` Mike Leach
2020-07-18 3:25 ` tingwei
2020-07-18 17:38 ` Mike Leach
2020-07-21 14:55 ` Mathieu Poirier
2020-07-21 23:22 ` tingwei
2020-07-20 6:58 ` Sai Prakash Ranjan
2020-07-21 7:03 ` Sai Prakash Ranjan
2020-07-17 5:45 ` [PATCH v3 09/20] coresight: allow etb " Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 10/20] coresight: allow tpiu " Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 11/20] coresight: allow tmc " Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 12/20] coresight: remove multiple init calls from funnel driver Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 13/20] coresight: remove multiple init calls from replicator driver Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 14/20] coresight: allow funnel and replicator drivers to be built as modules Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 15/20] coresight: cti: add function to register cti associate ops Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 16/20] coresight: allow cti to be built as a module Tingwei Zhang
2020-07-20 17:00 ` Mike Leach
2020-07-20 21:07 ` Mike Leach
2020-07-21 16:35 ` Mike Leach
2020-07-21 23:27 ` tingwei
2020-07-17 5:45 ` [PATCH v3 17/20] coresight: tmc-etr: add function to register catu ops Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 18/20] coresight: allow catu drivers to be built as modules Tingwei Zhang
2020-07-17 5:45 ` Tingwei Zhang [this message]
2020-07-22 10:49 ` [PATCH v3 19/20] coresight: add try_get_module() in coresight_grab_device() Suzuki K Poulose
2020-07-22 10:48 ` Greg KH
2020-07-22 11:26 ` Suzuki K Poulose
2020-07-23 0:18 ` tingwei
2020-07-23 0:35 ` tingwei
2020-07-22 10:51 ` Suzuki K Poulose
2020-07-23 0:19 ` tingwei
2020-07-23 19:36 ` Mathieu Poirier
2020-07-24 1:17 ` Tingwei Zhang
2020-07-17 5:45 ` [PATCH v3 20/20] coresight: allow the coresight core driver to be built as a module Tingwei Zhang
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