Commit e41aec79 authored by Lijun Pan's avatar Lijun Pan Committed by Jakub Kicinski
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ibmvnic: Ensure that CRQ entry read are correctly ordered 



Ensure that received Command-Response Queue (CRQ) entries are
properly read in order by the driver. dma_rmb barrier has
been added before accessing the CRQ descriptor to ensure
the entire descriptor is read before processing.

Fixes: 032c5e82 ("Driver for IBM System i/p VNIC protocol")
Signed-off-by: default avatarLijun Pan <ljp@linux.ibm.com>
Link: https://lore.kernel.org/r/20210128013442.88319-1-ljp@linux.ibm.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 0f764eec

drivers/net/ethernet/ibm/ibmvnic.c

+6 −0
Original line number Diff line number Diff line
@@ -5084,6 +5084,12 @@ static void ibmvnic_tasklet(struct tasklet_struct *t) 
	while (!done) {

		/* Pull all the valid messages off the CRQ */

		while ((crq = ibmvnic_next_crq(adapter)) != NULL) {

			/* This barrier makes sure ibmvnic_next_crq()'s

			 * crq->generic.first & IBMVNIC_CRQ_CMD_RSP is loaded

			 * before ibmvnic_handle_crq()'s

			 * switch(gen_crq->first) and switch(gen_crq->cmd).

			 */

			dma_rmb();

			ibmvnic_handle_crq(crq, adapter);

			crq->generic.first = 0;

		}