1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/net/ethernet/amazon/ena/ena_eth_com.h b/drivers/net/ethernet/amazon/ena/ena_eth_com.h
new file mode 100644
index 000000000..689313ee2
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_eth_com.h
@@ -0,0 +1,257 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/*
+ * Copyright 2015-2020 Amazon.com, Inc. or its affiliates. All rights reserved.
+ */
+
+#ifndef ENA_ETH_COM_H_
+#define ENA_ETH_COM_H_
+
+#include "ena_com.h"
+
+/* head update threshold in units of (queue size / ENA_COMP_HEAD_THRESH) */
+#define ENA_COMP_HEAD_THRESH 4
+
+struct ena_com_tx_ctx {
+	struct ena_com_tx_meta ena_meta;
+	struct ena_com_buf *ena_bufs;
+	/* For LLQ, header buffer - pushed to the device mem space */
+	void *push_header;
+
+	enum ena_eth_io_l3_proto_index l3_proto;
+	enum ena_eth_io_l4_proto_index l4_proto;
+	u16 num_bufs;
+	u16 req_id;
+	/* For regular queue, indicate the size of the header
+	 * For LLQ, indicate the size of the pushed buffer
+	 */
+	u16 header_len;
+
+	u8 meta_valid;
+	u8 tso_enable;
+	u8 l3_csum_enable;
+	u8 l4_csum_enable;
+	u8 l4_csum_partial;
+	u8 df; /* Don't fragment */
+};
+
+struct ena_com_rx_ctx {
+	struct ena_com_rx_buf_info *ena_bufs;
+	enum ena_eth_io_l3_proto_index l3_proto;
+	enum ena_eth_io_l4_proto_index l4_proto;
+	bool l3_csum_err;
+	bool l4_csum_err;
+	u8 l4_csum_checked;
+	/* fragmented packet */
+	bool frag;
+	u32 hash;
+	u16 descs;
+	int max_bufs;
+	u8 pkt_offset;
+};
+
+int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
+		       struct ena_com_tx_ctx *ena_tx_ctx,
+		       int *nb_hw_desc);
+
+int ena_com_rx_pkt(struct ena_com_io_cq *io_cq,
+		   struct ena_com_io_sq *io_sq,
+		   struct ena_com_rx_ctx *ena_rx_ctx);
+
+int ena_com_add_single_rx_desc(struct ena_com_io_sq *io_sq,
+			       struct ena_com_buf *ena_buf,
+			       u16 req_id);
+
+bool ena_com_cq_empty(struct ena_com_io_cq *io_cq);
+
+static inline void ena_com_unmask_intr(struct ena_com_io_cq *io_cq,
+				       struct ena_eth_io_intr_reg *intr_reg)
+{
+	writel(intr_reg->intr_control, io_cq->unmask_reg);
+}
+
+static inline int ena_com_free_q_entries(struct ena_com_io_sq *io_sq)
+{
+	u16 tail, next_to_comp, cnt;
+
+	next_to_comp = io_sq->next_to_comp;
+	tail = io_sq->tail;
+	cnt = tail - next_to_comp;
+
+	return io_sq->q_depth - 1 - cnt;
+}
+
+/* Check if the submission queue has enough space to hold required_buffers */
+static inline bool ena_com_sq_have_enough_space(struct ena_com_io_sq *io_sq,
+						u16 required_buffers)
+{
+	int temp;
+
+	if (io_sq->mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_HOST)
+		return ena_com_free_q_entries(io_sq) >= required_buffers;
+
+	/* This calculation doesn't need to be 100% accurate. So to reduce
+	 * the calculation overhead just Subtract 2 lines from the free descs
+	 * (one for the header line and one to compensate the devision
+	 * down calculation.
+	 */
+	temp = required_buffers / io_sq->llq_info.descs_per_entry + 2;
+
+	return ena_com_free_q_entries(io_sq) > temp;
+}
+
+static inline bool ena_com_meta_desc_changed(struct ena_com_io_sq *io_sq,
+					     struct ena_com_tx_ctx *ena_tx_ctx)
+{
+	if (!ena_tx_ctx->meta_valid)
+		return false;
+
+	return !!memcmp(&io_sq->cached_tx_meta,
+			&ena_tx_ctx->ena_meta,
+			sizeof(struct ena_com_tx_meta));
+}
+
+static inline bool is_llq_max_tx_burst_exists(struct ena_com_io_sq *io_sq)
+{
+	return (io_sq->mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) &&
+	       io_sq->llq_info.max_entries_in_tx_burst > 0;
+}
+
+static inline bool ena_com_is_doorbell_needed(struct ena_com_io_sq *io_sq,
+					      struct ena_com_tx_ctx *ena_tx_ctx)
+{
+	struct ena_com_llq_info *llq_info;
+	int descs_after_first_entry;
+	int num_entries_needed = 1;
+	u16 num_descs;
+
+	if (!is_llq_max_tx_burst_exists(io_sq))
+		return false;
+
+	llq_info = &io_sq->llq_info;
+	num_descs = ena_tx_ctx->num_bufs;
+
+	if (llq_info->disable_meta_caching ||
+	    unlikely(ena_com_meta_desc_changed(io_sq, ena_tx_ctx)))
+		++num_descs;
+
+	if (num_descs > llq_info->descs_num_before_header) {
+		descs_after_first_entry = num_descs - llq_info->descs_num_before_header;
+		num_entries_needed += DIV_ROUND_UP(descs_after_first_entry,
+						   llq_info->descs_per_entry);
+	}
+
+	netdev_dbg(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+		   "Queue: %d num_descs: %d num_entries_needed: %d\n",
+		   io_sq->qid, num_descs, num_entries_needed);
+
+	return num_entries_needed > io_sq->entries_in_tx_burst_left;
+}
+
+static inline int ena_com_write_sq_doorbell(struct ena_com_io_sq *io_sq)
+{
+	u16 max_entries_in_tx_burst = io_sq->llq_info.max_entries_in_tx_burst;
+	u16 tail = io_sq->tail;
+
+	netdev_dbg(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+		   "Write submission queue doorbell for queue: %d tail: %d\n",
+		   io_sq->qid, tail);
+
+	writel(tail, io_sq->db_addr);
+
+	if (is_llq_max_tx_burst_exists(io_sq)) {
+		netdev_dbg(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+			   "Reset available entries in tx burst for queue %d to %d\n",
+			   io_sq->qid, max_entries_in_tx_burst);
+		io_sq->entries_in_tx_burst_left = max_entries_in_tx_burst;
+	}
+
+	return 0;
+}
+
+static inline int ena_com_update_dev_comp_head(struct ena_com_io_cq *io_cq)
+{
+	u16 unreported_comp, head;
+	bool need_update;
+
+	if (unlikely(io_cq->cq_head_db_reg)) {
+		head = io_cq->head;
+		unreported_comp = head - io_cq->last_head_update;
+		need_update = unreported_comp > (io_cq->q_depth / ENA_COMP_HEAD_THRESH);
+
+		if (unlikely(need_update)) {
+			netdev_dbg(ena_com_io_cq_to_ena_dev(io_cq)->net_device,
+				   "Write completion queue doorbell for queue %d: head: %d\n",
+				   io_cq->qid, head);
+			writel(head, io_cq->cq_head_db_reg);
+			io_cq->last_head_update = head;
+		}
+	}
+
+	return 0;
+}
+
+static inline void ena_com_update_numa_node(struct ena_com_io_cq *io_cq,
+					    u8 numa_node)
+{
+	struct ena_eth_io_numa_node_cfg_reg numa_cfg;
+
+	if (!io_cq->numa_node_cfg_reg)
+		return;
+
+	numa_cfg.numa_cfg = (numa_node & ENA_ETH_IO_NUMA_NODE_CFG_REG_NUMA_MASK)
+		| ENA_ETH_IO_NUMA_NODE_CFG_REG_ENABLED_MASK;
+
+	writel(numa_cfg.numa_cfg, io_cq->numa_node_cfg_reg);
+}
+
+static inline void ena_com_comp_ack(struct ena_com_io_sq *io_sq, u16 elem)
+{
+	io_sq->next_to_comp += elem;
+}
+
+static inline void ena_com_cq_inc_head(struct ena_com_io_cq *io_cq)
+{
+	io_cq->head++;
+
+	/* Switch phase bit in case of wrap around */
+	if (unlikely((io_cq->head & (io_cq->q_depth - 1)) == 0))
+		io_cq->phase ^= 1;
+}
+
+static inline int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq,
+					     u16 *req_id)
+{
+	u8 expected_phase, cdesc_phase;
+	struct ena_eth_io_tx_cdesc *cdesc;
+	u16 masked_head;
+
+	masked_head = io_cq->head & (io_cq->q_depth - 1);
+	expected_phase = io_cq->phase;
+
+	cdesc = (struct ena_eth_io_tx_cdesc *)
+		((uintptr_t)io_cq->cdesc_addr.virt_addr +
+		(masked_head * io_cq->cdesc_entry_size_in_bytes));
+
+	/* When the current completion descriptor phase isn't the same as the
+	 * expected, it mean that the device still didn't update
+	 * this completion.
+	 */
+	cdesc_phase = READ_ONCE(cdesc->flags) & ENA_ETH_IO_TX_CDESC_PHASE_MASK;
+	if (cdesc_phase != expected_phase)
+		return -EAGAIN;
+
+	dma_rmb();
+
+	*req_id = READ_ONCE(cdesc->req_id);
+	if (unlikely(*req_id >= io_cq->q_depth)) {
+		netdev_err(ena_com_io_cq_to_ena_dev(io_cq)->net_device,
+			   "Invalid req id %d\n", cdesc->req_id);
+		return -EINVAL;
+	}
+
+	ena_com_cq_inc_head(io_cq);
+
+	return 0;
+}
+
+#endif /* ENA_ETH_COM_H_ */