[PATCH] dmaengine: idxd: remove interrupt flag for completion list spinlock

[PATCH] dmaengine: idxd: remove interrupt flag for completion list spinlock

[Dave Jiang]

The list lock is never acquired in interrupt context. Therefore there is no
need to disable interrupts. Remove interrupt flags for lock operations.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/dma/idxd/irq.c    |   12 +++++-------
 drivers/dma/idxd/submit.c |    5 ++---
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
index 2f895dccb3b4..210d22487b40 100644
--- a/drivers/dma/idxd/irq.c
+++ b/drivers/dma/idxd/irq.c
@@ -176,7 +176,6 @@ static void irq_process_pending_llist(struct idxd_irq_entry *irq_entry)
 {
 	struct idxd_desc *desc, *t;
 	struct llist_node *head;
-	unsigned long flags;
 
 	head = llist_del_all(&irq_entry->pending_llist);
 	if (!head)
@@ -197,17 +196,16 @@ static void irq_process_pending_llist(struct idxd_irq_entry *irq_entry)
 
 			complete_desc(desc, IDXD_COMPLETE_NORMAL);
 		} else {
-			spin_lock_irqsave(&irq_entry->list_lock, flags);
+			spin_lock(&irq_entry->list_lock);
 			list_add_tail(&desc->list,
 				      &irq_entry->work_list);
-			spin_unlock_irqrestore(&irq_entry->list_lock, flags);
+			spin_unlock(&irq_entry->list_lock);
 		}
 	}
 }
 
 static void irq_process_work_list(struct idxd_irq_entry *irq_entry)
 {
-	unsigned long flags;
 	LIST_HEAD(flist);
 	struct idxd_desc *desc, *n;
 
@@ -215,9 +213,9 @@ static void irq_process_work_list(struct idxd_irq_entry *irq_entry)
 	 * This lock protects list corruption from access of list outside of the irq handler
 	 * thread.
 	 */
-	spin_lock_irqsave(&irq_entry->list_lock, flags);
+	spin_lock(&irq_entry->list_lock);
 	if (list_empty(&irq_entry->work_list)) {
-		spin_unlock_irqrestore(&irq_entry->list_lock, flags);
+		spin_unlock(&irq_entry->list_lock);
 		return;
 	}
 
@@ -228,7 +226,7 @@ static void irq_process_work_list(struct idxd_irq_entry *irq_entry)
 		}
 	}
 
-	spin_unlock_irqrestore(&irq_entry->list_lock, flags);
+	spin_unlock(&irq_entry->list_lock);
 
 	list_for_each_entry(desc, &flist, list) {
 		u8 status = desc->completion->status & DSA_COMP_STATUS_MASK;
diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
index 92ae9a157cc9..4b514c63af15 100644
--- a/drivers/dma/idxd/submit.c
+++ b/drivers/dma/idxd/submit.c
@@ -106,14 +106,13 @@ static void llist_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie,
 {
 	struct idxd_desc *d, *t, *found = NULL;
 	struct llist_node *head;
-	unsigned long flags;
 
 	desc->completion->status = IDXD_COMP_DESC_ABORT;
 	/*
 	 * Grab the list lock so it will block the irq thread handler. This allows the
 	 * abort code to locate the descriptor need to be aborted.
 	 */
-	spin_lock_irqsave(&ie->list_lock, flags);
+	spin_lock(&ie->list_lock);
 	head = llist_del_all(&ie->pending_llist);
 	if (head) {
 		llist_for_each_entry_safe(d, t, head, llnode) {
@@ -127,7 +126,7 @@ static void llist_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie,
 
 	if (!found)
 		found = list_abort_desc(wq, ie, desc);
-	spin_unlock_irqrestore(&ie->list_lock, flags);
+	spin_unlock(&ie->list_lock);
 
 	if (found)
 		complete_desc(found, IDXD_COMPLETE_ABORT);

Re: [PATCH] dmaengine: idxd: remove interrupt flag for completion list spinlock

[Vinod Koul]

On 03-08-21, 15:29, Dave Jiang wrote:
> The list lock is never acquired in interrupt context. Therefore there is no
> need to disable interrupts. Remove interrupt flags for lock operations.

This fails to apply, pls rebase

-- 
~Vinod