linux/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c

// SPDX-License-Identifier: GPL-2.0
/* Marvell Octeon EP (EndPoint) Ethernet Driver
 *
 * Copyright (C) 2020 Marvell.
 *
 */

#include <linux/pci.h>
#include <linux/etherdevice.h>
#include <linux/vmalloc.h>

#include "octep_config.h"
#include "octep_main.h"

static void octep_oq_reset_indices(struct octep_oq *oq)
{ … }

/**
 * octep_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.
 *         -1, if failed to allocate a buffer or failed to map for DMA.
 */
static int octep_oq_fill_ring_buffers(struct octep_oq *oq)
{ … }

/**
 * octep_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_oq_refill(struct octep_device *oct, struct octep_oq *oq)
{ … }

/**
 * octep_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_setup_oq(struct octep_device *oct, int q_no)
{ … }

/**
 * octep_oq_free_ring_buffers() - Free ring buffers.
 *
 * @oq: Octeon Rx queue data structure.
 *
 * Free receive buffers in unused Rx queue descriptors.
 */
static void octep_oq_free_ring_buffers(struct octep_oq *oq)
{ … }

/**
 * octep_free_oq() - Free Rx queue resources.
 *
 * @oq: Octeon Rx queue data structure.
 *
 * Free all resources of a Rx queue.
 */
static int octep_free_oq(struct octep_oq *oq)
{ … }

/**
 * octep_setup_oqs() - setup resources for all Rx queues.
 *
 * @oct: Octeon device private data structure.
 */
int octep_setup_oqs(struct octep_device *oct)
{ … }

/**
 * octep_oq_dbell_init() - Initialize Rx queue doorbell.
 *
 * @oct: Octeon device private data structure.
 *
 * Write number of descriptors to Rx queue doorbell register.
 */
void octep_oq_dbell_init(struct octep_device *oct)
{ … }

/**
 * octep_free_oqs() - Free resources of all Rx queues.
 *
 * @oct: Octeon device private data structure.
 */
void octep_free_oqs(struct octep_device *oct)
{ … }

/**
 * octep_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_oq_check_hw_for_pkts(struct octep_device *oct,
				      struct octep_oq *oq)
{ … }

/**
 * octep_oq_next_pkt() - Move to the next packet in Rx queue.
 *
 * @oq: Octeon Rx queue data structure.
 * @buff_info: Current packet buffer info.
 * @read_idx: Current packet index in the ring.
 * @desc_used: Current packet descriptor number.
 *
 * Free the resources associated with a packet.
 * Increment packet index in the ring and packet descriptor number.
 */
static void octep_oq_next_pkt(struct octep_oq *oq,
			      struct octep_rx_buffer *buff_info,
			      u32 *read_idx, u32 *desc_used)
{ … }

/**
 * octep_oq_drop_rx() - Free the resources associated with a packet.
 *
 * @oq: Octeon Rx queue data structure.
 * @buff_info: Current packet buffer info.
 * @read_idx: Current packet index in the ring.
 * @desc_used: Current packet descriptor number.
 *
 */
static void octep_oq_drop_rx(struct octep_oq *oq,
			     struct octep_rx_buffer *buff_info,
			     u32 *read_idx, u32 *desc_used)
{ … }

/**
 * __octep_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_oq_process_rx(struct octep_device *oct,
				 struct octep_oq *oq, u16 pkts_to_process)
{ … }

/**
 * octep_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_oq_process_rx(struct octep_oq *oq, int budget)
{ … }