diff options
| author | hpreg@vmware.com <hpreg@vmware.com> | 2018-05-14 08:14:49 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-25 16:12:56 +0200 |
| commit | aab32922616365dc84d26972ade407f6ceb7bdff (patch) | |
| tree | 40bb378daf2cbb66e6e646b22d65f105527f9bd9 | |
| parent | 779fd38b60d86511f1ff17c29c2fc9ee2adb0697 (diff) | |
| download | linux-rt-aab32922616365dc84d26972ade407f6ceb7bdff.tar.gz | |
vmxnet3: use DMA memory barriers where required
[ Upstream commit f3002c1374fb2367c9d8dbb28852791ef90d2bac ]
The gen bits must be read first from (resp. written last to) DMA memory.
The proper way to enforce this on Linux is to call dma_rmb() (resp.
dma_wmb()).
Signed-off-by: Regis Duchesne <hpreg@vmware.com>
Acked-by: Ronak Doshi <doshir@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/net/vmxnet3/vmxnet3_drv.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index d27937fcdf85..c999b10531c5 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -369,6 +369,11 @@ vmxnet3_tq_tx_complete(struct vmxnet3_tx_queue *tq, gdesc = tq->comp_ring.base + tq->comp_ring.next2proc; while (VMXNET3_TCD_GET_GEN(&gdesc->tcd) == tq->comp_ring.gen) { + /* Prevent any &gdesc->tcd field from being (speculatively) + * read before (&gdesc->tcd)->gen is read. + */ + dma_rmb(); + completed += vmxnet3_unmap_pkt(VMXNET3_TCD_GET_TXIDX( &gdesc->tcd), tq, adapter->pdev, adapter); @@ -1099,6 +1104,11 @@ vmxnet3_tq_xmit(struct sk_buff *skb, struct vmxnet3_tx_queue *tq, gdesc->txd.tci = skb_vlan_tag_get(skb); } + /* Ensure that the write to (&gdesc->txd)->gen will be observed after + * all other writes to &gdesc->txd. + */ + dma_wmb(); + /* finally flips the GEN bit of the SOP desc. */ gdesc->dword[2] = cpu_to_le32(le32_to_cpu(gdesc->dword[2]) ^ VMXNET3_TXD_GEN); @@ -1286,6 +1296,12 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, */ break; } + + /* Prevent any rcd field from being (speculatively) read before + * rcd->gen is read. + */ + dma_rmb(); + BUG_ON(rcd->rqID != rq->qid && rcd->rqID != rq->qid2 && rcd->rqID != rq->dataRingQid); idx = rcd->rxdIdx; @@ -1515,6 +1531,12 @@ rcd_done: ring->next2comp = idx; num_to_alloc = vmxnet3_cmd_ring_desc_avail(ring); ring = rq->rx_ring + ring_idx; + + /* Ensure that the writes to rxd->gen bits will be observed + * after all other writes to rxd objects. + */ + dma_wmb(); + while (num_to_alloc) { vmxnet3_getRxDesc(rxd, &ring->base[ring->next2fill].rxd, &rxCmdDesc); |