[PATCH AUTOSEL 4.19 051/191] nfp: provide a better warning when ring allocation fails

Sasha Levin
2019-11-10T03:15:05Z

From: Jakub Kicinski <jakub.kicinski@netronome.com>

[ Upstream commit 23d9f5531c7c28546954b0bf332134a9b8a38c0a ]

NFP supports fairly enormous ring sizes (up to 256k descriptors).
In commit 466271703867 ("nfp: use kvcalloc() to allocate SW buffer
descriptor arrays") we have started using kvcalloc() functions to
make sure the allocation of software state arrays doesn't hit
the MAX_ORDER limit. Unfortunately, we can't use virtual mappings
for the DMA region holding HW descriptors. In case this allocation
fails instead of the generic (and fairly scary) warning/splat in
the logs print a helpful message explaining what happened and
suggesting how to fix it.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/ethernet/netronome/nfp/nfp_net_common.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index c6d29fdbb880f..d288c7eebacd8 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -2187,9 +2187,13 @@ nfp_net_tx_ring_alloc(struct nfp_net_dp *dp, struct nfp_net_tx_ring *tx_ring)

tx_ring->size = array_size(tx_ring->cnt, sizeof(*tx_ring->txds));
tx_ring->txds = dma_zalloc_coherent(dp->dev, tx_ring->size,
- &tx_ring->dma, GFP_KERNEL);
- if (!tx_ring->txds)
+ &tx_ring->dma,
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!tx_ring->txds) {
+ netdev_warn(dp->netdev, "failed to allocate TX descriptor ring memory, requested descriptor count: %d, consider lowering descriptor count\n",
+ tx_ring->cnt);
goto err_alloc;
+ }

tx_ring->txbufs = kvcalloc(tx_ring->cnt, sizeof(*tx_ring->txbufs),
GFP_KERNEL);
@@ -2341,9 +2345,13 @@ nfp_net_rx_ring_alloc(struct nfp_net_dp *dp, struct nfp_net_rx_ring *rx_ring)
rx_ring->cnt = dp->rxd_cnt;
rx_ring->size = array_size(rx_ring->cnt, sizeof(*rx_ring->rxds));
rx_ring->rxds = dma_zalloc_coherent(dp->dev, rx_ring->size,
- &rx_ring->dma, GFP_KERNEL);
- if (!rx_ring->rxds)
+ &rx_ring->dma,
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!rx_ring->rxds) {
+ netdev_warn(dp->netdev, "failed to allocate RX descriptor ring memory, requested descriptor count: %d, consider lowering descriptor count\n",
+ rx_ring->cnt);
goto err_alloc;
+ }

rx_ring->rxbufs = kvcalloc(rx_ring->cnt, sizeof(*rx_ring->rxbufs),
GFP_KERNEL);
--
2.20.1