From: Lijun Pan Date: Thu, 28 Jan 2021 01:34:42 +0000 (-0600) Subject: ibmvnic: Ensure that CRQ entry read are correctly ordered X-Git-Tag: rel_imx_5.10.35_2.0.0-somdevices.0~363^2~1906 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=3766a00d765dca6e2c05b18ab95c39fb2d00802c;p=linux.git ibmvnic: Ensure that CRQ entry read are correctly ordered commit e41aec79e62fa50f940cf222d1e9577f14e149dc upstream. 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: 032c5e82847a ("Driver for IBM System i/p VNIC protocol") Signed-off-by: Lijun Pan Link: https://lore.kernel.org/r/20210128013442.88319-1-ljp@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index e2540cc00d34..627ce1a20473 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -4979,6 +4979,12 @@ 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; }