dmaengine: idxd: Remove a useless mutex

ida_alloc()/ida_free() don't need any mutex, so remove this one.

It was introduced by commit e6fd6d7 ("dmaengine: idxd: add a device to
represent the file opened").

Signed-off-by: Christophe JAILLET <[email protected]>
Reviewed-by: Fenghua Yu <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Link: https://lore.kernel.org/r/e08df764e7046178ada4ec066852c0ce65410373.1730547933.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Vinod Koul <[email protected]>

Author: tititiou36

drivers/dma/idxd/cdev.c

@@ -28,7 +28,6 @@ struct idxd_cdev_context {
  * global to avoid conflict file names.
  */
 static DEFINE_IDA(file_ida);
-static DEFINE_MUTEX(ida_lock);
 
 /*
  * ictx is an array based off of accelerator types. enum idxd_type
@@ -123,9 +122,7 @@ static void idxd_file_dev_release(struct device *dev)
 	struct idxd_device *idxd = wq->idxd;
 	int rc;
 
-	mutex_lock(&ida_lock);
 	ida_free(&file_ida, ctx->id);
-	mutex_unlock(&ida_lock);
 
 	/* Wait for in-flight operations to complete. */
 	if (wq_shared(wq)) {
@@ -284,9 +281,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp)
 	}
 
 	idxd_cdev = wq->idxd_cdev;
-	mutex_lock(&ida_lock);
 	ctx->id = ida_alloc(&file_ida, GFP_KERNEL);
-	mutex_unlock(&ida_lock);
 	if (ctx->id < 0) {
 		dev_warn(dev, "ida alloc failure\n");
 		goto failed_ida;