1 files changed, 409 insertions, 0 deletions

diff --git a/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c
new file mode 100644
index 000000000000..f4f256a0dfea
--- /dev/null
+++ b/drivers/net/ethernet/hisilicon/hibmcge/hbg_txrx.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright (c) 2024 Hisilicon Limited.
+
+#include <net/netdev_queues.h>
+#include "hbg_common.h"
+#include "hbg_irq.h"
+#include "hbg_reg.h"
+#include "hbg_txrx.h"
+
+#define netdev_get_tx_ring(netdev) \
+			(&(((struct hbg_priv *)netdev_priv(netdev))->tx_ring))
+
+#define buffer_to_dma_dir(buffer) (((buffer)->dir == HBG_DIR_RX) ? \
+				   DMA_FROM_DEVICE : DMA_TO_DEVICE)
+
+#define hbg_queue_used_num(head, tail, ring) ({ \
+	typeof(ring) _ring = (ring); \
+	((tail) + _ring->len - (head)) % _ring->len; })
+#define hbg_queue_left_num(head, tail, ring) ({ \
+	typeof(ring) _r = (ring); \
+	_r->len - hbg_queue_used_num((head), (tail), _r) - 1; })
+#define hbg_queue_is_empty(head, tail, ring) \
+	(hbg_queue_used_num((head), (tail), (ring)) == 0)
+#define hbg_queue_is_full(head, tail, ring) \
+	(hbg_queue_left_num((head), (tail), (ring)) == 0)
+#define hbg_queue_next_prt(p, ring) (((p) + 1) % (ring)->len)
+#define hbg_queue_move_next(p, ring) ({ \
+	typeof(ring) _ring = (ring); \
+	_ring->p = hbg_queue_next_prt(_ring->p, _ring); })
+
+#define HBG_TX_STOP_THRS	2
+#define HBG_TX_START_THRS	(2 * HBG_TX_STOP_THRS)
+
+static int hbg_dma_map(struct hbg_buffer *buffer)
+{
+	struct hbg_priv *priv = buffer->priv;
+
+	buffer->skb_dma = dma_map_single(&priv->pdev->dev,
+					 buffer->skb->data, buffer->skb_len,
+					 buffer_to_dma_dir(buffer));
+	if (unlikely(dma_mapping_error(&priv->pdev->dev, buffer->skb_dma)))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void hbg_dma_unmap(struct hbg_buffer *buffer)
+{
+	struct hbg_priv *priv = buffer->priv;
+
+	if (unlikely(!buffer->skb_dma))
+		return;
+
+	dma_unmap_single(&priv->pdev->dev, buffer->skb_dma, buffer->skb_len,
+			 buffer_to_dma_dir(buffer));
+	buffer->skb_dma = 0;
+}
+
+static void hbg_init_tx_desc(struct hbg_buffer *buffer,
+			     struct hbg_tx_desc *tx_desc)
+{
+	u32 ip_offset = buffer->skb->network_header - buffer->skb->mac_header;
+	u32 word0 = 0;
+
+	word0 |= FIELD_PREP(HBG_TX_DESC_W0_WB_B, HBG_STATUS_ENABLE);
+	word0 |= FIELD_PREP(HBG_TX_DESC_W0_IP_OFF_M, ip_offset);
+	if (likely(buffer->skb->ip_summed == CHECKSUM_PARTIAL)) {
+		word0 |= FIELD_PREP(HBG_TX_DESC_W0_l3_CS_B, HBG_STATUS_ENABLE);
+		word0 |= FIELD_PREP(HBG_TX_DESC_W0_l4_CS_B, HBG_STATUS_ENABLE);
+	}
+
+	tx_desc->word0 = word0;
+	tx_desc->word1 = FIELD_PREP(HBG_TX_DESC_W1_SEND_LEN_M,
+				    buffer->skb->len);
+	tx_desc->word2 = buffer->skb_dma;
+	tx_desc->word3 = buffer->state_dma;
+}
+
+netdev_tx_t hbg_net_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct hbg_ring *ring = netdev_get_tx_ring(netdev);
+	struct hbg_priv *priv = netdev_priv(netdev);
+	/* This smp_load_acquire() pairs with smp_store_release() in
+	 * hbg_napi_tx_recycle() called in tx interrupt handle process.
+	 */
+	u32 ntc = smp_load_acquire(&ring->ntc);
+	struct hbg_buffer *buffer;
+	struct hbg_tx_desc tx_desc;
+	u32 ntu = ring->ntu;
+
+	if (unlikely(!skb->len ||
+		     skb->len > hbg_spec_max_frame_len(priv, HBG_DIR_TX))) {
+		dev_kfree_skb_any(skb);
+		netdev->stats.tx_errors++;
+		return NETDEV_TX_OK;
+	}
+
+	if (!netif_subqueue_maybe_stop(netdev, 0,
+				       hbg_queue_left_num(ntc, ntu, ring),
+				       HBG_TX_STOP_THRS, HBG_TX_START_THRS))
+		return NETDEV_TX_BUSY;
+
+	buffer = &ring->queue[ntu];
+	buffer->skb = skb;
+	buffer->skb_len = skb->len;
+	if (unlikely(hbg_dma_map(buffer))) {
+		dev_kfree_skb_any(skb);
+		return NETDEV_TX_OK;
+	}
+
+	buffer->state = HBG_TX_STATE_START;
+	hbg_init_tx_desc(buffer, &tx_desc);
+	hbg_hw_set_tx_desc(priv, &tx_desc);
+
+	/* This smp_store_release() pairs with smp_load_acquire() in
+	 * hbg_napi_tx_recycle() called in tx interrupt handle process.
+	 */
+	smp_store_release(&ring->ntu, hbg_queue_next_prt(ntu, ring));
+	dev_sw_netstats_tx_add(netdev, 1, skb->len);
+	return NETDEV_TX_OK;
+}
+
+static void hbg_buffer_free_skb(struct hbg_buffer *buffer)
+{
+	if (unlikely(!buffer->skb))
+		return;
+
+	dev_kfree_skb_any(buffer->skb);
+	buffer->skb = NULL;
+}
+
+static int hbg_buffer_alloc_skb(struct hbg_buffer *buffer)
+{
+	u32 len = hbg_spec_max_frame_len(buffer->priv, buffer->dir);
+	struct hbg_priv *priv = buffer->priv;
+
+	buffer->skb = netdev_alloc_skb(priv->netdev, len);
+	if (unlikely(!buffer->skb))
+		return -ENOMEM;
+
+	buffer->skb_len = len;
+	memset(buffer->skb->data, 0, HBG_PACKET_HEAD_SIZE);
+	return 0;
+}
+
+static void hbg_buffer_free(struct hbg_buffer *buffer)
+{
+	hbg_dma_unmap(buffer);
+	hbg_buffer_free_skb(buffer);
+}
+
+static int hbg_napi_tx_recycle(struct napi_struct *napi, int budget)
+{
+	struct hbg_ring *ring = container_of(napi, struct hbg_ring, napi);
+	/* This smp_load_acquire() pairs with smp_store_release() in
+	 * hbg_net_start_xmit() called in xmit process.
+	 */
+	u32 ntu = smp_load_acquire(&ring->ntu);
+	struct hbg_priv *priv = ring->priv;
+	struct hbg_buffer *buffer;
+	u32 ntc = ring->ntc;
+	int packet_done = 0;
+
+	/* We need do cleanup even if budget is 0.
+	 * Per NAPI documentation budget is for Rx.
+	 * So We hardcode the amount of work Tx NAPI does to 128.
+	 */
+	budget = 128;
+	while (packet_done < budget) {
+		if (unlikely(hbg_queue_is_empty(ntc, ntu, ring)))
+			break;
+
+		/* make sure HW write desc complete */
+		dma_rmb();
+
+		buffer = &ring->queue[ntc];
+		if (buffer->state != HBG_TX_STATE_COMPLETE)
+			break;
+
+		hbg_buffer_free(buffer);
+		ntc = hbg_queue_next_prt(ntc, ring);
+		packet_done++;
+	}
+
+	/* This smp_store_release() pairs with smp_load_acquire() in
+	 * hbg_net_start_xmit() called in xmit process.
+	 */
+	smp_store_release(&ring->ntc, ntc);
+	netif_wake_queue(priv->netdev);
+
+	if (likely(packet_done < budget &&
+		   napi_complete_done(napi, packet_done)))
+		hbg_hw_irq_enable(priv, HBG_INT_MSK_TX_B, true);
+
+	return packet_done;
+}
+
+static int hbg_rx_fill_one_buffer(struct hbg_priv *priv)
+{
+	struct hbg_ring *ring = &priv->rx_ring;
+	struct hbg_buffer *buffer;
+	int ret;
+
+	if (hbg_queue_is_full(ring->ntc, ring->ntu, ring))
+		return 0;
+
+	buffer = &ring->queue[ring->ntu];
+	ret = hbg_buffer_alloc_skb(buffer);
+	if (unlikely(ret))
+		return ret;
+
+	ret = hbg_dma_map(buffer);
+	if (unlikely(ret)) {
+		hbg_buffer_free_skb(buffer);
+		return ret;
+	}
+
+	hbg_hw_fill_buffer(priv, buffer->skb_dma);
+	hbg_queue_move_next(ntu, ring);
+	return 0;
+}
+
+static bool hbg_sync_data_from_hw(struct hbg_priv *priv,
+				  struct hbg_buffer *buffer)
+{
+	struct hbg_rx_desc *rx_desc;
+
+	/* make sure HW write desc complete */
+	dma_rmb();
+
+	dma_sync_single_for_cpu(&priv->pdev->dev, buffer->skb_dma,
+				buffer->skb_len, DMA_FROM_DEVICE);
+
+	rx_desc = (struct hbg_rx_desc *)buffer->skb->data;
+	return FIELD_GET(HBG_RX_DESC_W2_PKT_LEN_M, rx_desc->word2) != 0;
+}
+
+static int hbg_napi_rx_poll(struct napi_struct *napi, int budget)
+{
+	struct hbg_ring *ring = container_of(napi, struct hbg_ring, napi);
+	struct hbg_priv *priv = ring->priv;
+	struct hbg_rx_desc *rx_desc;
+	struct hbg_buffer *buffer;
+	u32 packet_done = 0;
+	u32 pkt_len;
+
+	while (packet_done < budget) {
+		if (unlikely(hbg_queue_is_empty(ring->ntc, ring->ntu, ring)))
+			break;
+
+		buffer = &ring->queue[ring->ntc];
+		if (unlikely(!buffer->skb))
+			goto next_buffer;
+
+		if (unlikely(!hbg_sync_data_from_hw(priv, buffer)))
+			break;
+		rx_desc = (struct hbg_rx_desc *)buffer->skb->data;
+		pkt_len = FIELD_GET(HBG_RX_DESC_W2_PKT_LEN_M, rx_desc->word2);
+
+		hbg_dma_unmap(buffer);
+
+		skb_reserve(buffer->skb, HBG_PACKET_HEAD_SIZE + NET_IP_ALIGN);
+		skb_put(buffer->skb, pkt_len);
+		buffer->skb->protocol = eth_type_trans(buffer->skb,
+						       priv->netdev);
+
+		dev_sw_netstats_rx_add(priv->netdev, pkt_len);
+		napi_gro_receive(napi, buffer->skb);
+		buffer->skb = NULL;
+
+next_buffer:
+		hbg_rx_fill_one_buffer(priv);
+		hbg_queue_move_next(ntc, ring);
+		packet_done++;
+	}
+
+	if (likely(packet_done < budget &&
+		   napi_complete_done(napi, packet_done)))
+		hbg_hw_irq_enable(priv, HBG_INT_MSK_RX_B, true);
+
+	return packet_done;
+}
+
+static void hbg_ring_uninit(struct hbg_ring *ring)
+{
+	struct hbg_buffer *buffer;
+	u32 i;
+
+	if (!ring->queue)
+		return;
+
+	napi_disable(&ring->napi);
+	netif_napi_del(&ring->napi);
+
+	for (i = 0; i < ring->len; i++) {
+		buffer = &ring->queue[i];
+		hbg_buffer_free(buffer);
+		buffer->ring = NULL;
+		buffer->priv = NULL;
+	}
+
+	dma_free_coherent(&ring->priv->pdev->dev,
+			  ring->len * sizeof(*ring->queue),
+			  ring->queue, ring->queue_dma);
+	ring->queue = NULL;
+	ring->queue_dma = 0;
+	ring->len = 0;
+	ring->priv = NULL;
+}
+
+static int hbg_ring_init(struct hbg_priv *priv, struct hbg_ring *ring,
+			 int (*napi_poll)(struct napi_struct *, int),
+			 enum hbg_dir dir)
+{
+	struct hbg_buffer *buffer;
+	u32 i, len;
+
+	len = hbg_get_spec_fifo_max_num(priv, dir) + 1;
+	ring->queue = dma_alloc_coherent(&priv->pdev->dev,
+					 len * sizeof(*ring->queue),
+					 &ring->queue_dma, GFP_KERNEL);
+	if (!ring->queue)
+		return -ENOMEM;
+
+	for (i = 0; i < len; i++) {
+		buffer = &ring->queue[i];
+		buffer->skb_len = 0;
+		buffer->dir = dir;
+		buffer->ring = ring;
+		buffer->priv = priv;
+		buffer->state_dma = ring->queue_dma + (i * sizeof(*buffer));
+	}
+
+	ring->dir = dir;
+	ring->priv = priv;
+	ring->ntc = 0;
+	ring->ntu = 0;
+	ring->len = len;
+
+	if (dir == HBG_DIR_TX)
+		netif_napi_add_tx(priv->netdev, &ring->napi, napi_poll);
+	else
+		netif_napi_add(priv->netdev, &ring->napi, napi_poll);
+
+	napi_enable(&ring->napi);
+	return 0;
+}
+
+static int hbg_tx_ring_init(struct hbg_priv *priv)
+{
+	struct hbg_ring *tx_ring = &priv->tx_ring;
+
+	if (!tx_ring->tout_log_buf)
+		tx_ring->tout_log_buf = devm_kmalloc(&priv->pdev->dev,
+						     HBG_TX_TIMEOUT_BUF_LEN,
+						     GFP_KERNEL);
+
+	if (!tx_ring->tout_log_buf)
+		return -ENOMEM;
+
+	return hbg_ring_init(priv, tx_ring, hbg_napi_tx_recycle, HBG_DIR_TX);
+}
+
+static int hbg_rx_ring_init(struct hbg_priv *priv)
+{
+	int ret;
+	u32 i;
+
+	ret = hbg_ring_init(priv, &priv->rx_ring, hbg_napi_rx_poll, HBG_DIR_RX);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < priv->rx_ring.len - 1; i++) {
+		ret = hbg_rx_fill_one_buffer(priv);
+		if (ret) {
+			hbg_ring_uninit(&priv->rx_ring);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+int hbg_txrx_init(struct hbg_priv *priv)
+{
+	int ret;
+
+	ret = hbg_tx_ring_init(priv);
+	if (ret) {
+		dev_err(&priv->pdev->dev,
+			"failed to init tx ring, ret = %d\n", ret);
+		return ret;
+	}
+
+	ret = hbg_rx_ring_init(priv);
+	if (ret) {
+		dev_err(&priv->pdev->dev,
+			"failed to init rx ring, ret = %d\n", ret);
+		hbg_ring_uninit(&priv->tx_ring);
+	}
+
+	return ret;
+}
+
+void hbg_txrx_uninit(struct hbg_priv *priv)
+{
+	hbg_ring_uninit(&priv->tx_ring);
+	hbg_ring_uninit(&priv->rx_ring);
+}