diff options
| author | Thomas Falcon <tlfalcon@linux.ibm.com> | 2020-12-01 09:52:10 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-12-01 10:09:04 -0800 |
| commit | b71ec952234610b4f90ef17a2fdcb124d5320070 (patch) | |
| tree | fa2ca8f1ae8fc7d8b776f10a5a7e49b877c2487e /drivers/net | |
| parent | 237f977ab920490502f5fe39af4390f26db2cd40 (diff) | |
ibmvnic: Ensure that SCRQ entry reads are correctly ordered
Ensure that received Subordinate Command-Response Queue (SCRQ)
entries are properly read in order by the driver. These queues
are used in the ibmvnic device to process RX buffer and TX completion
descriptors. dma_rmb barriers have been added after checking for a
pending descriptor to ensure the correct descriptor entry is checked
and after reading the SCRQ descriptor to ensure the entire
descriptor is read before processing.
Fixes: 032c5e82847a ("Driver for IBM System i/p VNIC protocol")
Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/ibm/ibmvnic.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index bca1becd33f0..0e34c36c3e86 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2404,6 +2404,12 @@ restart_poll: if (!pending_scrq(adapter, adapter->rx_scrq[scrq_num])) break; + /* The queue entry at the current index is peeked at above + * to determine that there is a valid descriptor awaiting + * processing. We want to be sure that the current slot + * holds a valid descriptor before reading its contents. + */ + dma_rmb(); next = ibmvnic_next_scrq(adapter, adapter->rx_scrq[scrq_num]); rx_buff = (struct ibmvnic_rx_buff *)be64_to_cpu(next-> @@ -3113,6 +3119,13 @@ restart_loop: unsigned int pool = scrq->pool_index; int num_entries = 0; + /* The queue entry at the current index is peeked at above + * to determine that there is a valid descriptor awaiting + * processing. We want to be sure that the current slot + * holds a valid descriptor before reading its contents. + */ + dma_rmb(); + next = ibmvnic_next_scrq(adapter, scrq); for (i = 0; i < next->tx_comp.num_comps; i++) { if (next->tx_comp.rcs[i]) { @@ -3513,6 +3526,11 @@ static union sub_crq *ibmvnic_next_scrq(struct ibmvnic_adapter *adapter, } spin_unlock_irqrestore(&scrq->lock, flags); + /* Ensure that the entire buffer descriptor has been + * loaded before reading its contents + */ + dma_rmb(); + return entry; } |