Commit de7b3f81 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'ibmvnic-Bug-fixes-for-queue-descriptor-processing' 



Thomas Falcon says:

====================
ibmvnic: Bug fixes for queue descriptor processing

This series resolves a few issues in the ibmvnic driver's
RX buffer and TX completion processing. The first patch
includes memory barriers to synchronize queue descriptor
reads. The second patch fixes a memory leak that could
occur if the device returns a TX completion with an error
code in the descriptor, in which case the respective socket
buffer and other relevant data structures may not be freed
or updated properly.

v3: Correct length of Fixes tags, requested by Jakub Kicinski

v2: Provide more detailed comments explaining specifically what
    reads are being ordered, suggested by Michael Ellerman
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 237f977a ba246c17

drivers/net/ethernet/ibm/ibmvnic.c

+19 −3
Original line number Diff line number Diff line
@@ -2404,6 +2404,12 @@ static int ibmvnic_poll(struct napi_struct *napi, int budget) 


		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->
@@ -3113,13 +3119,18 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter, 
		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]) {

			if (next->tx_comp.rcs[i])

				dev_err(dev, "tx error %x\n",

					next->tx_comp.rcs[i]);

				continue;

			}

			index = be32_to_cpu(next->tx_comp.correlators[i]);

			if (index & IBMVNIC_TSO_POOL_MASK) {

				tx_pool = &adapter->tso_pool[pool];
@@ -3513,6 +3524,11 @@ 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;

}