From 147e81ec7568933a51fe58b64244383e929870fb Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg Date: Mon, 18 Apr 2016 11:33:49 -0700 Subject: [PATCH] i40e: Test memory before ethtool alloc succeeds When testing on systems with very limited amounts of RAM, a bug was found where, while changing the number of descriptors using ethtool, the driver didn't test the limits of system memory before permanently assuming it would be able to get receive buffer memory. Work around this issue by pre-allocation of the receive buffer memory, in the "ghost" ring, which is then used during reinit using the new ring length. Change-Id: I92d7a5fb59a6c884b2efdd1ec652845f101c3359 Signed-off-by: Jesse Brandeburg Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- .../net/ethernet/intel/i40e/i40e_ethtool.c | 34 +++++++++++++++++-- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c index 6fd730ac23a1..51a994d85870 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c +++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c @@ -1274,6 +1274,13 @@ static int i40e_set_ringparam(struct net_device *netdev, } for (i = 0; i < vsi->num_queue_pairs; i++) { + /* this is to allow wr32 to have something to write to + * during early allocation of Rx buffers + */ + u32 __iomem faketail = 0; + struct i40e_ring *ring; + u16 unused; + /* clone ring and setup updated count */ rx_rings[i] = *vsi->rx_rings[i]; rx_rings[i].count = new_rx_count; @@ -1282,12 +1289,22 @@ static int i40e_set_ringparam(struct net_device *netdev, */ rx_rings[i].desc = NULL; rx_rings[i].rx_bi = NULL; + rx_rings[i].tail = (u8 __iomem *)&faketail; err = i40e_setup_rx_descriptors(&rx_rings[i]); + if (err) + goto rx_unwind; + + /* now allocate the Rx buffers to make sure the OS + * has enough memory, any failure here means abort + */ + ring = &rx_rings[i]; + unused = I40E_DESC_UNUSED(ring); + err = i40e_alloc_rx_buffers(ring, unused); +rx_unwind: if (err) { - while (i) { - i--; + do { i40e_free_rx_resources(&rx_rings[i]); - } + } while (i--); kfree(rx_rings); rx_rings = NULL; @@ -1313,6 +1330,17 @@ static int i40e_set_ringparam(struct net_device *netdev, if (rx_rings) { for (i = 0; i < vsi->num_queue_pairs; i++) { i40e_free_rx_resources(vsi->rx_rings[i]); + /* get the real tail offset */ + rx_rings[i].tail = vsi->rx_rings[i]->tail; + /* this is to fake out the allocation routine + * into thinking it has to realloc everything + * but the recycling logic will let us re-use + * the buffers allocated above + */ + rx_rings[i].next_to_use = 0; + rx_rings[i].next_to_clean = 0; + rx_rings[i].next_to_alloc = 0; + /* do a struct copy */ *vsi->rx_rings[i] = rx_rings[i]; } kfree(rx_rings); -- 2.20.1