On 10/30/2023 9:55 PM, 'Guanjun' wrote:
From: Guanjun <guanjun@xxxxxxxxxxxxxxxxx>
The int_handle field in hw descriptor should also be protected
by wmb() before possibly triggering a DMA read.
Fixes: ec0d64231615 (dmaengine: idxd: embed irq_entry in idxd_wq struct)
I think the direct fix is to eb0cf33a91b4 which moves the interrupt
handle assignment to idxd_submit_desc() and has a write to
desc->hw->int_handle before submission of desc->hw.
Fixes: eb0cf33a91b4 ("dmaengine: idxd: move interrupt handle assignment")
Other than that,
Reviewed-by: Lijun Pan <lijun.pan@xxxxxxxxx>
Signed-off-by: Guanjun <guanjun@xxxxxxxxxxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
---
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 {
