[PATCH AUTOSEL 4.14 18/61] net: hns: fix for unmapping problem when SMMU is on

Sasha Levin
2018-10-16T04:14:25Z

From: Yunsheng Lin <linyunsheng@huawei.com>

[ Upstream commit 2e9361efa707e186d91b938e44f9e326725259f7 ]

If SMMU is on, there is more likely that skb_shinfo(skb)->frags[i]
can not send by a single BD. when this happen, the
hns_nic_net_xmit_hw function map the whole data in a frags using
skb_frag_dma_map, but unmap each BD' data individually when tx is
done, which causes problem when SMMU is on.

This patch fixes this problem by ummapping the whole data in a
frags when tx is done.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Reviewed-by: Yisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/hisilicon/hns/hnae.c | 2 +-
drivers/net/ethernet/hisilicon/hns/hns_enet.c | 30 ++++++++++++-------
2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hnae.c b/drivers/net/ethernet/hisilicon/hns/hnae.c
index a051e582d541..79d03f8ee7b1 100644
--- a/drivers/net/ethernet/hisilicon/hns/hnae.c
+++ b/drivers/net/ethernet/hisilicon/hns/hnae.c
@@ -84,7 +84,7 @@ static void hnae_unmap_buffer(struct hnae_ring *ring, struct hnae_desc_cb *cb)
if (cb->type == DESC_TYPE_SKB)
dma_unmap_single(ring_to_dev(ring), cb->dma, cb->length,
ring_to_dma_dir(ring));
- else
+ else if (cb->length)
dma_unmap_page(ring_to_dev(ring), cb->dma, cb->length,
ring_to_dma_dir(ring));
}
diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.c b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
index 07d6a9cf2c55..4faadc3ffe8c 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
@@ -40,9 +40,9 @@
#define SKB_TMP_LEN(SKB) \
(((SKB)->transport_header - (SKB)->mac_header) + tcp_hdrlen(SKB))

-static void fill_v2_desc(struct hnae_ring *ring, void *priv,
- int size, dma_addr_t dma, int frag_end,
- int buf_num, enum hns_desc_type type, int mtu)
+static void fill_v2_desc_hw(struct hnae_ring *ring, void *priv, int size,
+ int send_sz, dma_addr_t dma, int frag_end,
+ int buf_num, enum hns_desc_type type, int mtu)
{
struct hnae_desc *desc = &ring->desc[ring->next_to_use];
struct hnae_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_use];
@@ -64,7 +64,7 @@ static void fill_v2_desc(struct hnae_ring *ring, void *priv,
desc_cb->type = type;

desc->addr = cpu_to_le64(dma);
- desc->tx.send_size = cpu_to_le16((u16)size);
+ desc->tx.send_size = cpu_to_le16((u16)send_sz);

/* config bd buffer end */
hnae_set_bit(rrcfv, HNSV2_TXD_VLD_B, 1);
@@ -133,6 +133,14 @@ static void fill_v2_desc(struct hnae_ring *ring, void *priv,
ring_ptr_move_fw(ring, next_to_use);
}

+static void fill_v2_desc(struct hnae_ring *ring, void *priv,
+ int size, dma_addr_t dma, int frag_end,
+ int buf_num, enum hns_desc_type type, int mtu)
+{
+ fill_v2_desc_hw(ring, priv, size, size, dma, frag_end,
+ buf_num, type, mtu);
+}
+
static const struct acpi_device_id hns_enet_acpi_match[] = {
{ "HISI00C1", 0 },
{ "HISI00C2", 0 },
@@ -289,15 +297,15 @@ static void fill_tso_desc(struct hnae_ring *ring, void *priv,

/* when the frag size is bigger than hardware, split this frag */
for (k = 0; k < frag_buf_num; k++)
- fill_v2_desc(ring, priv,
- (k == frag_buf_num - 1) ?
+ fill_v2_desc_hw(ring, priv, k == 0 ? size : 0,
+ (k == frag_buf_num - 1) ?
sizeoflast : BD_MAX_SEND_SIZE,
- dma + BD_MAX_SEND_SIZE * k,
- frag_end && (k == frag_buf_num - 1) ? 1 : 0,
- buf_num,
- (type == DESC_TYPE_SKB && !k) ?
+ dma + BD_MAX_SEND_SIZE * k,
+ frag_end && (k == frag_buf_num - 1) ? 1 : 0,
+ buf_num,
+ (type == DESC_TYPE_SKB && !k) ?
DESC_TYPE_SKB : DESC_TYPE_PAGE,
- mtu);
+ mtu);
}

netdev_tx_t hns_nic_net_xmit_hw(struct net_device *ndev,
--
2.17.1