1 files changed, 510 insertions, 0 deletions

diff --git a/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c
new file mode 100644
index 000000000..82821bc28
--- /dev/null
+++ b/drivers/net/ethernet/marvell/octeon_ep_vf/octep_vf_rx.c
@@ -0,0 +1,510 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Marvell Octeon EP (EndPoint) VF Ethernet Driver
+ *
+ * Copyright (C) 2020 Marvell.
+ *
+ */
+
+#include <linux/pci.h>
+#include <linux/etherdevice.h>
+#include <linux/vmalloc.h>
+
+#include "octep_vf_config.h"
+#include "octep_vf_main.h"
+
+static void octep_vf_oq_reset_indices(struct octep_vf_oq *oq)
+{
+	oq->host_read_idx = 0;
+	oq->host_refill_idx = 0;
+	oq->refill_count = 0;
+	oq->last_pkt_count = 0;
+	oq->pkts_pending = 0;
+}
+
+/**
+ * octep_vf_oq_fill_ring_buffers() - fill initial receive buffers for Rx ring.
+ *
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Return: 0, if successfully filled receive buffers for all descriptors.
+ *         -ENOMEM, if failed to allocate a buffer or failed to map for DMA.
+ */
+static int octep_vf_oq_fill_ring_buffers(struct octep_vf_oq *oq)
+{
+	struct octep_vf_oq_desc_hw *desc_ring = oq->desc_ring;
+	struct page *page;
+	u32 i;
+
+	for (i = 0; i < oq->max_count; i++) {
+		page = dev_alloc_page();
+		if (unlikely(!page)) {
+			dev_err(oq->dev, "Rx buffer alloc failed\n");
+			goto rx_buf_alloc_err;
+		}
+		desc_ring[i].buffer_ptr = dma_map_page(oq->dev, page, 0,
+						       PAGE_SIZE,
+						       DMA_FROM_DEVICE);
+		if (dma_mapping_error(oq->dev, desc_ring[i].buffer_ptr)) {
+			dev_err(oq->dev,
+				"OQ-%d buffer alloc: DMA mapping error!\n",
+				oq->q_no);
+			goto dma_map_err;
+		}
+		oq->buff_info[i].page = page;
+	}
+
+	return 0;
+
+dma_map_err:
+	put_page(page);
+rx_buf_alloc_err:
+	while (i) {
+		i--;
+		dma_unmap_page(oq->dev, desc_ring[i].buffer_ptr, PAGE_SIZE, DMA_FROM_DEVICE);
+		put_page(oq->buff_info[i].page);
+		oq->buff_info[i].page = NULL;
+	}
+
+	return -ENOMEM;
+}
+
+/**
+ * octep_vf_oq_refill() - refill buffers for used Rx ring descriptors.
+ *
+ * @oct: Octeon device private data structure.
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Return: number of descriptors successfully refilled with receive buffers.
+ */
+static int octep_vf_oq_refill(struct octep_vf_device *oct, struct octep_vf_oq *oq)
+{
+	struct octep_vf_oq_desc_hw *desc_ring = oq->desc_ring;
+	struct page *page;
+	u32 refill_idx, i;
+
+	refill_idx = oq->host_refill_idx;
+	for (i = 0; i < oq->refill_count; i++) {
+		page = dev_alloc_page();
+		if (unlikely(!page)) {
+			dev_err(oq->dev, "refill: rx buffer alloc failed\n");
+			oq->stats.alloc_failures++;
+			break;
+		}
+
+		desc_ring[refill_idx].buffer_ptr = dma_map_page(oq->dev, page, 0,
+								PAGE_SIZE, DMA_FROM_DEVICE);
+		if (dma_mapping_error(oq->dev, desc_ring[refill_idx].buffer_ptr)) {
+			dev_err(oq->dev,
+				"OQ-%d buffer refill: DMA mapping error!\n",
+				oq->q_no);
+			put_page(page);
+			oq->stats.alloc_failures++;
+			break;
+		}
+		oq->buff_info[refill_idx].page = page;
+		refill_idx++;
+		if (refill_idx == oq->max_count)
+			refill_idx = 0;
+	}
+	oq->host_refill_idx = refill_idx;
+	oq->refill_count -= i;
+
+	return i;
+}
+
+/**
+ * octep_vf_setup_oq() - Setup a Rx queue.
+ *
+ * @oct: Octeon device private data structure.
+ * @q_no: Rx queue number to be setup.
+ *
+ * Allocate resources for a Rx queue.
+ */
+static int octep_vf_setup_oq(struct octep_vf_device *oct, int q_no)
+{
+	struct octep_vf_oq *oq;
+	u32 desc_ring_size;
+
+	oq = vzalloc(sizeof(*oq));
+	if (!oq)
+		goto create_oq_fail;
+	oct->oq[q_no] = oq;
+
+	oq->octep_vf_dev = oct;
+	oq->netdev = oct->netdev;
+	oq->dev = &oct->pdev->dev;
+	oq->q_no = q_no;
+	oq->max_count = CFG_GET_OQ_NUM_DESC(oct->conf);
+	oq->ring_size_mask = oq->max_count - 1;
+	oq->buffer_size = CFG_GET_OQ_BUF_SIZE(oct->conf);
+	oq->max_single_buffer_size = oq->buffer_size - OCTEP_VF_OQ_RESP_HW_SIZE;
+
+	/* When the hardware/firmware supports additional capabilities,
+	 * additional header is filled-in by Octeon after length field in
+	 * Rx packets. this header contains additional packet information.
+	 */
+	if (oct->fw_info.rx_ol_flags)
+		oq->max_single_buffer_size -= OCTEP_VF_OQ_RESP_HW_EXT_SIZE;
+
+	oq->refill_threshold = CFG_GET_OQ_REFILL_THRESHOLD(oct->conf);
+
+	desc_ring_size = oq->max_count * OCTEP_VF_OQ_DESC_SIZE;
+	oq->desc_ring = dma_alloc_coherent(oq->dev, desc_ring_size,
+					   &oq->desc_ring_dma, GFP_KERNEL);
+
+	if (unlikely(!oq->desc_ring)) {
+		dev_err(oq->dev,
+			"Failed to allocate DMA memory for OQ-%d !!\n", q_no);
+		goto desc_dma_alloc_err;
+	}
+
+	oq->buff_info = vzalloc(oq->max_count * OCTEP_VF_OQ_RECVBUF_SIZE);
+
+	if (unlikely(!oq->buff_info)) {
+		dev_err(&oct->pdev->dev,
+			"Failed to allocate buffer info for OQ-%d\n", q_no);
+		goto buf_list_err;
+	}
+
+	if (octep_vf_oq_fill_ring_buffers(oq))
+		goto oq_fill_buff_err;
+
+	octep_vf_oq_reset_indices(oq);
+	oct->hw_ops.setup_oq_regs(oct, q_no);
+	oct->num_oqs++;
+
+	return 0;
+
+oq_fill_buff_err:
+	vfree(oq->buff_info);
+	oq->buff_info = NULL;
+buf_list_err:
+	dma_free_coherent(oq->dev, desc_ring_size,
+			  oq->desc_ring, oq->desc_ring_dma);
+	oq->desc_ring = NULL;
+desc_dma_alloc_err:
+	vfree(oq);
+	oct->oq[q_no] = NULL;
+create_oq_fail:
+	return -ENOMEM;
+}
+
+/**
+ * octep_vf_oq_free_ring_buffers() - Free ring buffers.
+ *
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Free receive buffers in unused Rx queue descriptors.
+ */
+static void octep_vf_oq_free_ring_buffers(struct octep_vf_oq *oq)
+{
+	struct octep_vf_oq_desc_hw *desc_ring = oq->desc_ring;
+	int  i;
+
+	if (!oq->desc_ring || !oq->buff_info)
+		return;
+
+	for (i = 0; i < oq->max_count; i++)  {
+		if (oq->buff_info[i].page) {
+			dma_unmap_page(oq->dev, desc_ring[i].buffer_ptr,
+				       PAGE_SIZE, DMA_FROM_DEVICE);
+			put_page(oq->buff_info[i].page);
+			oq->buff_info[i].page = NULL;
+			desc_ring[i].buffer_ptr = 0;
+		}
+	}
+	octep_vf_oq_reset_indices(oq);
+}
+
+/**
+ * octep_vf_free_oq() - Free Rx queue resources.
+ *
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Free all resources of a Rx queue.
+ */
+static int octep_vf_free_oq(struct octep_vf_oq *oq)
+{
+	struct octep_vf_device *oct = oq->octep_vf_dev;
+	int q_no = oq->q_no;
+
+	octep_vf_oq_free_ring_buffers(oq);
+
+	vfree(oq->buff_info);
+
+	if (oq->desc_ring)
+		dma_free_coherent(oq->dev,
+				  oq->max_count * OCTEP_VF_OQ_DESC_SIZE,
+				  oq->desc_ring, oq->desc_ring_dma);
+
+	vfree(oq);
+	oct->oq[q_no] = NULL;
+	oct->num_oqs--;
+	return 0;
+}
+
+/**
+ * octep_vf_setup_oqs() - setup resources for all Rx queues.
+ *
+ * @oct: Octeon device private data structure.
+ */
+int octep_vf_setup_oqs(struct octep_vf_device *oct)
+{
+	int i, retval = 0;
+
+	oct->num_oqs = 0;
+	for (i = 0; i < CFG_GET_PORTS_ACTIVE_IO_RINGS(oct->conf); i++) {
+		retval = octep_vf_setup_oq(oct, i);
+		if (retval) {
+			dev_err(&oct->pdev->dev,
+				"Failed to setup OQ(RxQ)-%d.\n", i);
+			goto oq_setup_err;
+		}
+		dev_dbg(&oct->pdev->dev, "Successfully setup OQ(RxQ)-%d.\n", i);
+	}
+
+	return 0;
+
+oq_setup_err:
+	while (i) {
+		i--;
+		octep_vf_free_oq(oct->oq[i]);
+	}
+	return retval;
+}
+
+/**
+ * octep_vf_oq_dbell_init() - Initialize Rx queue doorbell.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Write number of descriptors to Rx queue doorbell register.
+ */
+void octep_vf_oq_dbell_init(struct octep_vf_device *oct)
+{
+	int i;
+
+	for (i = 0; i < oct->num_oqs; i++)
+		writel(oct->oq[i]->max_count, oct->oq[i]->pkts_credit_reg);
+}
+
+/**
+ * octep_vf_free_oqs() - Free resources of all Rx queues.
+ *
+ * @oct: Octeon device private data structure.
+ */
+void octep_vf_free_oqs(struct octep_vf_device *oct)
+{
+	int i;
+
+	for (i = 0; i < CFG_GET_PORTS_ACTIVE_IO_RINGS(oct->conf); i++) {
+		if (!oct->oq[i])
+			continue;
+		octep_vf_free_oq(oct->oq[i]);
+		dev_dbg(&oct->pdev->dev,
+			"Successfully freed OQ(RxQ)-%d.\n", i);
+	}
+}
+
+/**
+ * octep_vf_oq_check_hw_for_pkts() - Check for new Rx packets.
+ *
+ * @oct: Octeon device private data structure.
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Return: packets received after previous check.
+ */
+static int octep_vf_oq_check_hw_for_pkts(struct octep_vf_device *oct,
+					 struct octep_vf_oq *oq)
+{
+	u32 pkt_count, new_pkts;
+
+	pkt_count = readl(oq->pkts_sent_reg);
+	new_pkts = pkt_count - oq->last_pkt_count;
+
+	/* Clear the hardware packets counter register if the rx queue is
+	 * being processed continuously with-in a single interrupt and
+	 * reached half its max value.
+	 * this counter is not cleared every time read, to save write cycles.
+	 */
+	if (unlikely(pkt_count > 0xF0000000U)) {
+		writel(pkt_count, oq->pkts_sent_reg);
+		pkt_count = readl(oq->pkts_sent_reg);
+		new_pkts += pkt_count;
+	}
+	oq->last_pkt_count = pkt_count;
+	oq->pkts_pending += new_pkts;
+	return new_pkts;
+}
+
+/**
+ * __octep_vf_oq_process_rx() - Process hardware Rx queue and push to stack.
+ *
+ * @oct: Octeon device private data structure.
+ * @oq: Octeon Rx queue data structure.
+ * @pkts_to_process: number of packets to be processed.
+ *
+ * Process the new packets in Rx queue.
+ * Packets larger than single Rx buffer arrive in consecutive descriptors.
+ * But, count returned by the API only accounts full packets, not fragments.
+ *
+ * Return: number of packets processed and pushed to stack.
+ */
+static int __octep_vf_oq_process_rx(struct octep_vf_device *oct,
+				    struct octep_vf_oq *oq, u16 pkts_to_process)
+{
+	struct octep_vf_oq_resp_hw_ext *resp_hw_ext = NULL;
+	netdev_features_t feat = oq->netdev->features;
+	struct octep_vf_rx_buffer *buff_info;
+	struct octep_vf_oq_resp_hw *resp_hw;
+	u32 pkt, rx_bytes, desc_used;
+	u16 data_offset, rx_ol_flags;
+	struct sk_buff *skb;
+	u32 read_idx;
+
+	read_idx = oq->host_read_idx;
+	rx_bytes = 0;
+	desc_used = 0;
+	for (pkt = 0; pkt < pkts_to_process; pkt++) {
+		buff_info = (struct octep_vf_rx_buffer *)&oq->buff_info[read_idx];
+		dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
+			       PAGE_SIZE, DMA_FROM_DEVICE);
+		resp_hw = page_address(buff_info->page);
+		buff_info->page = NULL;
+
+		/* Swap the length field that is in Big-Endian to CPU */
+		buff_info->len = be64_to_cpu(resp_hw->length);
+		if (oct->fw_info.rx_ol_flags) {
+			/* Extended response header is immediately after
+			 * response header (resp_hw)
+			 */
+			resp_hw_ext = (struct octep_vf_oq_resp_hw_ext *)
+				      (resp_hw + 1);
+			buff_info->len -= OCTEP_VF_OQ_RESP_HW_EXT_SIZE;
+			/* Packet Data is immediately after
+			 * extended response header.
+			 */
+			data_offset = OCTEP_VF_OQ_RESP_HW_SIZE +
+				      OCTEP_VF_OQ_RESP_HW_EXT_SIZE;
+			rx_ol_flags = resp_hw_ext->rx_ol_flags;
+		} else {
+			/* Data is immediately after
+			 * Hardware Rx response header.
+			 */
+			data_offset = OCTEP_VF_OQ_RESP_HW_SIZE;
+			rx_ol_flags = 0;
+		}
+		rx_bytes += buff_info->len;
+
+		if (buff_info->len <= oq->max_single_buffer_size) {
+			skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
+			skb_reserve(skb, data_offset);
+			skb_put(skb, buff_info->len);
+			read_idx++;
+			desc_used++;
+			if (read_idx == oq->max_count)
+				read_idx = 0;
+		} else {
+			struct skb_shared_info *shinfo;
+			u16 data_len;
+
+			skb = napi_build_skb((void *)resp_hw, PAGE_SIZE);
+			skb_reserve(skb, data_offset);
+			/* Head fragment includes response header(s);
+			 * subsequent fragments contains only data.
+			 */
+			skb_put(skb, oq->max_single_buffer_size);
+			read_idx++;
+			desc_used++;
+			if (read_idx == oq->max_count)
+				read_idx = 0;
+
+			shinfo = skb_shinfo(skb);
+			data_len = buff_info->len - oq->max_single_buffer_size;
+			while (data_len) {
+				dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
+					       PAGE_SIZE, DMA_FROM_DEVICE);
+				buff_info = (struct octep_vf_rx_buffer *)
+					    &oq->buff_info[read_idx];
+				if (data_len < oq->buffer_size) {
+					buff_info->len = data_len;
+					data_len = 0;
+				} else {
+					buff_info->len = oq->buffer_size;
+					data_len -= oq->buffer_size;
+				}
+
+				skb_add_rx_frag(skb, shinfo->nr_frags,
+						buff_info->page, 0,
+						buff_info->len,
+						buff_info->len);
+				buff_info->page = NULL;
+				read_idx++;
+				desc_used++;
+				if (read_idx == oq->max_count)
+					read_idx = 0;
+			}
+		}
+
+		skb->dev = oq->netdev;
+		skb->protocol = eth_type_trans(skb, skb->dev);
+		if (feat & NETIF_F_RXCSUM &&
+		    OCTEP_VF_RX_CSUM_VERIFIED(rx_ol_flags))
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		else
+			skb->ip_summed = CHECKSUM_NONE;
+		napi_gro_receive(oq->napi, skb);
+	}
+
+	oq->host_read_idx = read_idx;
+	oq->refill_count += desc_used;
+	oq->stats.packets += pkt;
+	oq->stats.bytes += rx_bytes;
+
+	return pkt;
+}
+
+/**
+ * octep_vf_oq_process_rx() - Process Rx queue.
+ *
+ * @oq: Octeon Rx queue data structure.
+ * @budget: max number of packets can be processed in one invocation.
+ *
+ * Check for newly received packets and process them.
+ * Keeps checking for new packets until budget is used or no new packets seen.
+ *
+ * Return: number of packets processed.
+ */
+int octep_vf_oq_process_rx(struct octep_vf_oq *oq, int budget)
+{
+	u32 pkts_available, pkts_processed, total_pkts_processed;
+	struct octep_vf_device *oct = oq->octep_vf_dev;
+
+	pkts_available = 0;
+	pkts_processed = 0;
+	total_pkts_processed = 0;
+	while (total_pkts_processed < budget) {
+		 /* update pending count only when current one exhausted */
+		if (oq->pkts_pending == 0)
+			octep_vf_oq_check_hw_for_pkts(oct, oq);
+		pkts_available = min(budget - total_pkts_processed,
+				     oq->pkts_pending);
+		if (!pkts_available)
+			break;
+
+		pkts_processed = __octep_vf_oq_process_rx(oct, oq,
+							  pkts_available);
+		oq->pkts_pending -= pkts_processed;
+		total_pkts_processed += pkts_processed;
+	}
+
+	if (oq->refill_count >= oq->refill_threshold) {
+		u32 desc_refilled = octep_vf_oq_refill(oct, oq);
+
+		/* flush pending writes before updating credits */
+		smp_wmb();
+		writel(desc_refilled, oq->pkts_credit_reg);
+	}
+
+	return total_pkts_processed;
+}