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| author |   Jakub Kicinski <kuba@kernel.org> | 2021-02-01 20:21:14 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-01 20:21:14 -0800 |
| commit | 9ae4bdc6e4c1281ddf8d6335bea35864d086cbf9 (patch) | |
| tree | ee0204797ce611fa7f4612782439daf32046e4e2 /drivers/net | |
| parent | Merge tag 'mlx5-dr-2021-01-29' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux (diff) | |
| parent | ibmvnic: remove unnecessary rmb() inside ibmvnic_poll (diff) | |
| download | wireguard-linux-9ae4bdc6e4c1281ddf8d6335bea35864d086cbf9.tar.xz wireguard-linux-9ae4bdc6e4c1281ddf8d6335bea35864d086cbf9.zip | |
Merge branch 'rework-the-memory-barrier-for-scrq-entry'
Lijun Pan says:
====================
rework the memory barrier for SCRQ entry
This series rework the memory barrier for SCRQ (Sub-Command-Response
Queue) entry.
====================
Link: https://lore.kernel.org/r/20210130011905.1485-1-ljp@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ethernet/ibm/ibmvnic.c | 31 |
1 files changed, 11 insertions, 20 deletions
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index a40af510018a..0ed169ef1cfc 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2444,12 +2444,6 @@ restart_poll: if (!pending_scrq(adapter, rx_scrq)) 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, rx_scrq); rx_buff = (struct ibmvnic_rx_buff *)be64_to_cpu(next-> @@ -2516,7 +2510,6 @@ restart_poll: if (napi_complete_done(napi, frames_processed)) { enable_scrq_irq(adapter, rx_scrq); if (pending_scrq(adapter, rx_scrq)) { - rmb(); if (napi_reschedule(napi)) { disable_scrq_irq(adapter, rx_scrq); goto restart_poll; @@ -3189,13 +3182,6 @@ restart_loop: int total_bytes = 0; int num_packets = 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]) @@ -3569,11 +3555,16 @@ static int pending_scrq(struct ibmvnic_adapter *adapter, struct ibmvnic_sub_crq_queue *scrq) { union sub_crq *entry = &scrq->msgs[scrq->cur]; + int rc; - if (entry->generic.first & IBMVNIC_CRQ_CMD_RSP) - return 1; - else - return 0; + rc = !!(entry->generic.first & IBMVNIC_CRQ_CMD_RSP); + + /* Ensure that the SCRQ valid flag is loaded prior to loading the + * contents of the SCRQ descriptor + */ + dma_rmb(); + + return rc; } static union sub_crq *ibmvnic_next_scrq(struct ibmvnic_adapter *adapter, @@ -3592,8 +3583,8 @@ 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 + /* Ensure that the SCRQ valid flag is loaded prior to loading the + * contents of the SCRQ descriptor */ dma_rmb(); |