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authorNoralf Trønnes <noralf@tronnes.org>2018-03-28 10:38:35 +0300
committerOleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>2018-03-29 13:19:20 +0300
commitbee330f3d67273a68dcb99f59480d59553c008b2 (patch)
treeabe48e9b35c199bf691b02efc40a5291f2391b40 /include/drm
parent790861cc34f872015806cef311d5c64cc3167a0d (diff)
drm: Use srcu to protect drm_device.unplugged
Use srcu to protect drm_device.unplugged in a race free manner. Drivers can use drm_dev_enter()/drm_dev_exit() to protect and mark sections preventing access to device resources that are not available after the device is gone. Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Tested-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Cc: intel-gfx@lists.freedesktop.org Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/1522222715-11814-1-git-send-email-andr2000@gmail.com
Diffstat (limited to 'include/drm')
-rw-r--r--include/drm/drm_device.h9
-rw-r--r--include/drm/drm_drv.h15
2 files changed, 19 insertions, 5 deletions
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 7c4fa32f3fc6..3a0eac2885b7 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -46,7 +46,14 @@ struct drm_device {
/* currently active master for this device. Protected by master_mutex */
struct drm_master *master;
- atomic_t unplugged; /**< Flag whether dev is dead */
+ /**
+ * @unplugged:
+ *
+ * Flag to tell if the device has been unplugged.
+ * See drm_dev_enter() and drm_dev_is_unplugged().
+ */
+ bool unplugged;
+
struct inode *anon_inode; /**< inode for private address-space */
char *unique; /**< unique name of the device */
/*@} */
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index d32b688eb346..ff7312c40cd8 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -623,6 +623,8 @@ void drm_dev_get(struct drm_device *dev);
void drm_dev_put(struct drm_device *dev);
void drm_dev_unref(struct drm_device *dev);
void drm_put_dev(struct drm_device *dev);
+bool drm_dev_enter(struct drm_device *dev, int *idx);
+void drm_dev_exit(int idx);
void drm_dev_unplug(struct drm_device *dev);
/**
@@ -634,11 +636,16 @@ void drm_dev_unplug(struct drm_device *dev);
* unplugged, these two functions guarantee that any store before calling
* drm_dev_unplug() is visible to callers of this function after it completes
*/
-static inline int drm_dev_is_unplugged(struct drm_device *dev)
+static inline bool drm_dev_is_unplugged(struct drm_device *dev)
{
- int ret = atomic_read(&dev->unplugged);
- smp_rmb();
- return ret;
+ int idx;
+
+ if (drm_dev_enter(dev, &idx)) {
+ drm_dev_exit(idx);
+ return false;
+ }
+
+ return true;
}