From 80fc671bcc0173836e9032b0c698ea74c13b9d7c Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Fri, 1 Jul 2022 11:48:43 +0800 Subject: uacce: Handle parent device removal or parent driver module rmmod The uacce driver must deal with a possible removal of the parent device or parent driver module rmmod at any time. Although uacce_remove(), called on device removal and on driver unbind, prevents future use of the uacce fops by removing the cdev, fops that were called before that point may still be running. Serialize uacce_fops_open() and uacce_remove() with uacce->mutex. Serialize other fops against uacce_remove() with q->mutex. Since we need to protect uacce_fops_poll() which gets called on the fast path, replace uacce->queues_lock with q->mutex to improve scalability. The other fops are only used during setup. uacce_queue_is_valid(), checked under q->mutex or uacce->mutex, denotes whether uacce_remove() has disabled all queues. If that is the case, don't go any further since the parent device is being removed and uacce->ops should not be called anymore. Reported-by: Yang Shen Signed-off-by: Zhangfei Gao Signed-off-by: Jean-Philippe Brucker Link: https://lore.kernel.org/r/20220701034843.7502-1-zhangfei.gao@linaro.org Signed-off-by: Greg Kroah-Hartman --- include/linux/uacce.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uacce.h b/include/linux/uacce.h index 48e319f40275..9ce88c28b0a8 100644 --- a/include/linux/uacce.h +++ b/include/linux/uacce.h @@ -70,6 +70,7 @@ enum uacce_q_state { * @wait: wait queue head * @list: index into uacce queues list * @qfrs: pointer of qfr regions + * @mutex: protects queue state * @state: queue state machine * @pasid: pasid associated to the mm * @handle: iommu_sva handle returned by iommu_sva_bind_device() @@ -80,6 +81,7 @@ struct uacce_queue { wait_queue_head_t wait; struct list_head list; struct uacce_qfile_region *qfrs[UACCE_MAX_REGION]; + struct mutex mutex; enum uacce_q_state state; u32 pasid; struct iommu_sva *handle; @@ -97,9 +99,9 @@ struct uacce_queue { * @dev_id: id of the uacce device * @cdev: cdev of the uacce * @dev: dev of the uacce + * @mutex: protects uacce operation * @priv: private pointer of the uacce * @queues: list of queues - * @queues_lock: lock for queues list * @inode: core vfs */ struct uacce_device { @@ -113,9 +115,9 @@ struct uacce_device { u32 dev_id; struct cdev *cdev; struct device dev; + struct mutex mutex; void *priv; struct list_head queues; - struct mutex queues_lock; struct inode *inode; }; -- cgit v1.2.3