diff mbox series

[v1,1/2] dmaengine: idxd: Protect int_handle field in hw descriptor

Message ID 20231029080049.1482701-2-guanjun@linux.alibaba.com
State New
Headers
Series Some fixes for idxd driver |

Commit Message

guanjun Oct. 29, 2023, 8 a.m. UTC 
  From: Guanjun <guanjun@linux.alibaba.com>

The int_handle field in hw descriptor should also be protected
by wmb() before possibly triggering a DMA read.

Signed-off-by: Guanjun <guanjun@linux.alibaba.com>
---
 drivers/dma/idxd/submit.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

Comments

Dave Jiang Oct. 30, 2023, 3:58 p.m. UTC | #1 
On 10/29/23 01:00, 'Guanjun' wrote:
> From: Guanjun <guanjun@linux.alibaba.com>
> 
> The int_handle field in hw descriptor should also be protected
> by wmb() before possibly triggering a DMA read.
> 
> Signed-off-by: Guanjun <guanjun@linux.alibaba.com>

Can you please provide a Fix tag? Otherwise
Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/dma/idxd/submit.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
> index c01db23e3333..3f922518e3a5 100644
> --- a/drivers/dma/idxd/submit.c
> +++ b/drivers/dma/idxd/submit.c
> @@ -182,13 +182,6 @@ int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
>  
>  	portal = idxd_wq_portal_addr(wq);
>  
> -	/*
> -	 * The wmb() flushes writes to coherent DMA data before
> -	 * possibly triggering a DMA read. The wmb() is necessary
> -	 * even on UP because the recipient is a device.
> -	 */
> -	wmb();
> -
>  	/*
>  	 * Pending the descriptor to the lockless list for the irq_entry
>  	 * that we designated the descriptor to.
> @@ -199,6 +192,13 @@ int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
>  		llist_add(&desc->llnode, &ie->pending_llist);
>  	}
>  
> +	/*
> +	 * The wmb() flushes writes to coherent DMA data before
> +	 * possibly triggering a DMA read. The wmb() is necessary
> +	 * even on UP because the recipient is a device.
> +	 */
> +	wmb();
> +
>  	if (wq_dedicated(wq)) {
>  		iosubmit_cmds512(portal, desc->hw, 1);
>  	} else {
Fenghua Yu Oct. 30, 2023, 6:56 p.m. UTC | #2 
On 10/29/23 01:00, 'Guanjun' wrote:
> From: Guanjun <guanjun@linux.alibaba.com>
> 
> The int_handle field in hw descriptor should also be protected
> by wmb() before possibly triggering a DMA read.
> 
> Signed-off-by: Guanjun <guanjun@linux.alibaba.com>

As Dave said, need to add fixes tag.

Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>

Thanks.

-Fenghua Yu
diff mbox series

Patch

diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
index c01db23e3333..3f922518e3a5 100644
--- a/drivers/dma/idxd/submit.c
+++ b/drivers/dma/idxd/submit.c
@@ -182,13 +182,6 @@  int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
 
 	portal = idxd_wq_portal_addr(wq);
 
-	/*
-	 * The wmb() flushes writes to coherent DMA data before
-	 * possibly triggering a DMA read. The wmb() is necessary
-	 * even on UP because the recipient is a device.
-	 */
-	wmb();
-
 	/*
 	 * Pending the descriptor to the lockless list for the irq_entry
 	 * that we designated the descriptor to.
@@ -199,6 +192,13 @@  int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
 		llist_add(&desc->llnode, &ie->pending_llist);
 	}
 
+	/*
+	 * The wmb() flushes writes to coherent DMA data before
+	 * possibly triggering a DMA read. The wmb() is necessary
+	 * even on UP because the recipient is a device.
+	 */
+	wmb();
+
 	if (wq_dedicated(wq)) {
 		iosubmit_cmds512(portal, desc->hw, 1);
 	} else {