From: Netanel Belgazal netanel@amazon.com
[ Upstream commit ef5b0771d247379c90c8bf1332ff32f7f74bff7f ]
The buffer length field in the ena rx descriptor is 16 bit, and the current driver passes a full page in each ena rx descriptor. When PAGE_SIZE equals 64kB or more, the buffer length field becomes zero. To solve this issue, limit the ena Rx descriptor to use 16kB even when allocating 64kB kernel pages. This change would not impact ena device functionality, as 16kB is still larger than maximum MTU.
Signed-off-by: Netanel Belgazal netanel@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/net/ethernet/amazon/ena/ena_netdev.c | 10 +++++----- drivers/net/ethernet/amazon/ena/ena_netdev.h | 11 +++++++++++ 2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 67df5053dc30..60b3ee29d82c 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -456,7 +456,7 @@ static inline int ena_alloc_rx_page(struct ena_ring *rx_ring, return -ENOMEM; }
- dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, + dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE, DMA_FROM_DEVICE); if (unlikely(dma_mapping_error(rx_ring->dev, dma))) { u64_stats_update_begin(&rx_ring->syncp); @@ -473,7 +473,7 @@ static inline int ena_alloc_rx_page(struct ena_ring *rx_ring, rx_info->page_offset = 0; ena_buf = &rx_info->ena_buf; ena_buf->paddr = dma; - ena_buf->len = PAGE_SIZE; + ena_buf->len = ENA_PAGE_SIZE;
return 0; } @@ -490,7 +490,7 @@ static void ena_free_rx_page(struct ena_ring *rx_ring, return; }
- dma_unmap_page(rx_ring->dev, ena_buf->paddr, PAGE_SIZE, + dma_unmap_page(rx_ring->dev, ena_buf->paddr, ENA_PAGE_SIZE, DMA_FROM_DEVICE);
__free_page(page); @@ -910,10 +910,10 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring, do { dma_unmap_page(rx_ring->dev, dma_unmap_addr(&rx_info->ena_buf, paddr), - PAGE_SIZE, DMA_FROM_DEVICE); + ENA_PAGE_SIZE, DMA_FROM_DEVICE);
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page, - rx_info->page_offset, len, PAGE_SIZE); + rx_info->page_offset, len, ENA_PAGE_SIZE);
netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev, "rx skb updated. len %d. data_len %d\n", diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h index 29bb5704260b..3404376c28ca 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.h +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h @@ -350,4 +350,15 @@ void ena_dump_stats_to_buf(struct ena_adapter *adapter, u8 *buf);
int ena_get_sset_count(struct net_device *netdev, int sset);
+/* The ENA buffer length fields is 16 bit long. So when PAGE_SIZE == 64kB the + * driver passas 0. + * Since the max packet size the ENA handles is ~9kB limit the buffer length to + * 16kB. + */ +#if PAGE_SIZE > SZ_16K +#define ENA_PAGE_SIZE SZ_16K +#else +#define ENA_PAGE_SIZE PAGE_SIZE +#endif + #endif /* !(ENA_H) */