[PATCH V3,net-next, 3/4] net: mana: Enable RX path to handle various MTU sizes

Haiyang Zhang
2023-04-12T21:18:00Z

Update RX data path to allocate and use RX queue DMA buffers with
proper size based on potentially various MTU sizes.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
---
V3:
Refectored to multiple patches for readability. Suggested by Jacob Keller.

V2:
Refectored to multiple patches for readability. Suggested by Yunsheng Lin.

---
drivers/net/ethernet/microsoft/mana/mana_en.c | 38 ++++++++++++++-----
include/net/mana/mana.h | 7 ++++
2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 911954ff84ee..8e7fa6e9c3b5 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -1185,10 +1185,10 @@ static void mana_post_pkt_rxq(struct mana_rxq *rxq)
WARN_ON_ONCE(recv_buf_oob->wqe_inf.wqe_size_in_bu != 1);
}

-static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
- struct xdp_buff *xdp)
+static struct sk_buff *mana_build_skb(struct mana_rxq *rxq, void *buf_va,
+ uint pkt_len, struct xdp_buff *xdp)
{
- struct sk_buff *skb = napi_build_skb(buf_va, PAGE_SIZE);
+ struct sk_buff *skb = napi_build_skb(buf_va, rxq->alloc_size);

if (!skb)
return NULL;
@@ -1196,11 +1196,12 @@ static struct sk_buff *mana_build_skb(void *buf_va, uint pkt_len,
if (xdp->data_hard_start) {
skb_reserve(skb, xdp->data - xdp->data_hard_start);
skb_put(skb, xdp->data_end - xdp->data);
- } else {
- skb_reserve(skb, XDP_PACKET_HEADROOM);
- skb_put(skb, pkt_len);
+ return skb;
}

+ skb_reserve(skb, rxq->headroom);
+ skb_put(skb, pkt_len);
+
return skb;
}

@@ -1233,7 +1234,7 @@ static void mana_rx_skb(void *buf_va, struct mana_rxcomp_oob *cqe,
if (act != XDP_PASS && act != XDP_TX)
goto drop_xdp;

- skb = mana_build_skb(buf_va, pkt_len, &xdp);
+ skb = mana_build_skb(rxq, buf_va, pkt_len, &xdp);

if (!skb)
goto drop;
@@ -1301,6 +1302,14 @@ static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
if (rxq->xdp_save_va) {
va = rxq->xdp_save_va;
rxq->xdp_save_va = NULL;
+ } else if (rxq->alloc_size > PAGE_SIZE) {
+ if (is_napi)
+ va = napi_alloc_frag(rxq->alloc_size);
+ else
+ va = netdev_alloc_frag(rxq->alloc_size);
+
+ if (!va)
+ return NULL;
} else {
page = dev_alloc_page();
if (!page)
@@ -1309,7 +1318,7 @@ static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
va = page_to_virt(page);
}

- *da = dma_map_single(dev, va + XDP_PACKET_HEADROOM, rxq->datasize,
+ *da = dma_map_single(dev, va + rxq->headroom, rxq->datasize,
DMA_FROM_DEVICE);

if (dma_mapping_error(dev, *da)) {
@@ -1732,7 +1741,7 @@ static int mana_alloc_rx_wqe(struct mana_port_context *apc,
u32 buf_idx;
int ret;

- WARN_ON(rxq->datasize == 0 || rxq->datasize > PAGE_SIZE);
+ WARN_ON(rxq->datasize == 0);

*rxq_size = 0;
*cq_size = 0;
@@ -1788,6 +1797,7 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
struct gdma_dev *gd = apc->ac->gdma_dev;
struct mana_obj_spec wq_spec;
struct mana_obj_spec cq_spec;
+ unsigned int mtu = ndev->mtu;
struct gdma_queue_spec spec;
struct mana_cq *cq = NULL;
struct gdma_context *gc;
@@ -1807,7 +1817,15 @@ static struct mana_rxq *mana_create_rxq(struct mana_port_context *apc,
rxq->rxq_idx = rxq_idx;
rxq->rxobj = INVALID_MANA_HANDLE;

- rxq->datasize = ALIGN(ETH_FRAME_LEN, 64);
+ rxq->datasize = ALIGN(mtu + ETH_HLEN, 64);
+
+ if (mtu > MANA_XDP_MTU_MAX) {
+ rxq->alloc_size = mtu + MANA_RXBUF_PAD;
+ rxq->headroom = 0;
+ } else {
+ rxq->alloc_size = mtu + MANA_RXBUF_PAD + XDP_PACKET_HEADROOM;
+ rxq->headroom = XDP_PACKET_HEADROOM;
+ }

err = mana_alloc_rx_wqe(apc, rxq, &rq_size, &cq_size);
if (err)
diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 037bcabf6b98..fee99d704281 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -291,6 +291,11 @@ struct mana_recv_buf_oob {
struct gdma_posted_wqe_info wqe_inf;
};

+#define MANA_RXBUF_PAD (SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) \
+ + ETH_HLEN)
+
+#define MANA_XDP_MTU_MAX (PAGE_SIZE - MANA_RXBUF_PAD - XDP_PACKET_HEADROOM)
+
struct mana_rxq {
struct gdma_queue *gdma_rq;
/* Cache the gdma receive queue id */
@@ -300,6 +305,8 @@ struct mana_rxq {
u32 rxq_idx;

u32 datasize;
+ u32 alloc_size;
+ u32 headroom;

mana_handle_t rxobj;

--
2.25.1