From: Mihai Carabas <mihai.carabas@oracle.com>
To: linux-kernel@vger.kernel.org
Cc: Peng Hao <peng.hao2@zte.com.cn>,
Mihai Carabas <mihai.carabas@oracle.com>
Subject: [PATCH 3/4] misc/pvpanic: Avoid initializing multiple pvpanic devices
Date: Thu, 29 Oct 2020 13:43:06 +0200 [thread overview]
Message-ID: <1603971787-16784-4-git-send-email-mihai.carabas@oracle.com> (raw)
In-Reply-To: <1603971787-16784-1-git-send-email-mihai.carabas@oracle.com>
From: Peng Hao <peng.hao2@zte.com.cn>
Avoid initializing multiple pvpanic devices when configure multiple
pvpanic device driver type. Make sure that only one pvpanic device
is working.
Signed-off-by: Peng Hao <peng.hao2@zte.com.cn>
Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
---
drivers/misc/pvpanic/pvpanic.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c
index 4c831f5..8c7b534 100644
--- a/drivers/misc/pvpanic/pvpanic.c
+++ b/drivers/misc/pvpanic/pvpanic.c
@@ -17,10 +17,13 @@
#include <uapi/misc/pvpanic.h>
static struct {
+ struct mutex lock;
struct platform_device *pdev;
void __iomem *base;
bool is_ioport;
-} pvpanic_data;
+} pvpanic_data = {
+ .lock = __MUTEX_INITIALIZER(pvpanic_data.lock),
+};
MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>");
MODULE_DESCRIPTION("pvpanic device driver");
@@ -56,9 +59,17 @@ int pvpanic_add_device(struct device *dev, struct resource *res)
struct platform_device *pdev;
int ret;
+ mutex_lock(&pvpanic_data.lock);
+ if (pvpanic_data.pdev) {
+ mutex_unlock(&pvpanic_data.lock);
+ return -EEXIST;
+ }
+
pdev = platform_device_alloc("pvpanic", -1);
- if (!pdev)
+ if (!pdev) {
+ mutex_unlock(&pvpanic_data.lock);
return -ENOMEM;
+ }
pdev->dev.parent = dev;
@@ -70,9 +81,11 @@ int pvpanic_add_device(struct device *dev, struct resource *res)
if (ret)
goto err;
pvpanic_data.pdev = pdev;
+ mutex_unlock(&pvpanic_data.lock);
return 0;
err:
+ mutex_unlock(&pvpanic_data.lock);
platform_device_put(pdev);
return ret;
}
@@ -80,8 +93,10 @@ int pvpanic_add_device(struct device *dev, struct resource *res)
void pvpanic_remove_device(void)
{
+ mutex_lock(&pvpanic_data.lock);
platform_device_unregister(pvpanic_data.pdev);
pvpanic_data.pdev = NULL;
+ mutex_unlock(&pvpanic_data.lock);
}
EXPORT_SYMBOL_GPL(pvpanic_remove_device);
--
1.8.3.1
next prev parent reply other threads:[~2020-10-29 12:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-29 11:43 [PATCH] add support for pci in the pvpanic driver Mihai Carabas
2020-10-29 11:43 ` [PATCH 1/4] misc/pvpanic : preparing for pvpanic driver framework Mihai Carabas
2020-10-29 17:02 ` Andy Shevchenko
2020-10-29 11:43 ` [PATCH 2/4] misc/pvpanic: Add " Mihai Carabas
2020-10-29 13:48 ` kernel test robot
2020-10-29 14:48 ` kernel test robot
2020-10-29 11:43 ` Mihai Carabas [this message]
2020-10-29 11:43 ` [PATCH 4/4] misc/pvpanic: add new pvpanic pci driver Mihai Carabas
2020-11-23 13:18 ` Re [PATCH] add support for pci in the pvpanic driver Mihai Carabas
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