altera_sgdma.c | Explore in Territory

// SPDX-License-Identifier: GPL-2.0-only
/* Altera TSE SGDMA and MSGDMA Linux driver
 * Copyright (C) 2014 Altera Corporation. All rights reserved
 */

#include <linux/list.h>
#include "altera_utils.h"
#include "altera_tse.h"
#include "altera_sgdmahw.h"
#include "altera_sgdma.h"

static void sgdma_setup_descrip(struct sgdma_descrip __iomem *desc,
				struct sgdma_descrip __iomem *ndesc,
				dma_addr_t ndesc_phys,
				dma_addr_t raddr,
				dma_addr_t waddr,
				u16 length,
				int generate_eop,
				int rfixed,
				int wfixed);

static int sgdma_async_write(struct altera_tse_private *priv,
			      struct sgdma_descrip __iomem *desc);

static int sgdma_async_read(struct altera_tse_private *priv);

static dma_addr_t
sgdma_txphysaddr(struct altera_tse_private *priv,
		 struct sgdma_descrip __iomem *desc);

static dma_addr_t
sgdma_rxphysaddr(struct altera_tse_private *priv,
		 struct sgdma_descrip __iomem *desc);

static int sgdma_txbusy(struct altera_tse_private *priv);

static int sgdma_rxbusy(struct altera_tse_private *priv);

static void
queue_tx(struct altera_tse_private *priv, struct tse_buffer *buffer);

static void
queue_rx(struct altera_tse_private *priv, struct tse_buffer *buffer);

static struct tse_buffer *
dequeue_tx(struct altera_tse_private *priv);

static struct tse_buffer *
dequeue_rx(struct altera_tse_private *priv);

static struct tse_buffer *
queue_rx_peekhead(struct altera_tse_private *priv);

int sgdma_initialize(struct altera_tse_private *priv)
{ … }

void sgdma_uninitialize(struct altera_tse_private *priv)
{ … }

/* This function resets the SGDMA controller and clears the
 * descriptor memory used for transmits and receives.
 */
void sgdma_reset(struct altera_tse_private *priv)
{ … }

/* For SGDMA, interrupts remain enabled after initially enabling,
 * so no need to provide implementations for abstract enable
 * and disable
 */

void sgdma_enable_rxirq(struct altera_tse_private *priv)
{ … }

void sgdma_enable_txirq(struct altera_tse_private *priv)
{ … }

void sgdma_disable_rxirq(struct altera_tse_private *priv)
{ … }

void sgdma_disable_txirq(struct altera_tse_private *priv)
{ … }

void sgdma_clear_rxirq(struct altera_tse_private *priv)
{ … }

void sgdma_clear_txirq(struct altera_tse_private *priv)
{ … }

/* transmits buffer through SGDMA. Returns number of buffers
 * transmitted, 0 if not possible.
 *
 * tx_lock is held by the caller
 */
int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer)
{ … }


/* tx_lock held to protect access to queued tx list
 */
u32 sgdma_tx_completions(struct altera_tse_private *priv)
{ … }

void sgdma_start_rxdma(struct altera_tse_private *priv)
{ … }

void sgdma_add_rx_desc(struct altera_tse_private *priv,
		       struct tse_buffer *rxbuffer)
{ … }

/* status is returned on upper 16 bits,
 * length is returned in lower 16 bits
 */
u32 sgdma_rx_status(struct altera_tse_private *priv)
{ … }


/* Private functions */
static void sgdma_setup_descrip(struct sgdma_descrip __iomem *desc,
				struct sgdma_descrip __iomem *ndesc,
				dma_addr_t ndesc_phys,
				dma_addr_t raddr,
				dma_addr_t waddr,
				u16 length,
				int generate_eop,
				int rfixed,
				int wfixed)
{ … }

/* If hardware is busy, don't restart async read.
 * if status register is 0 - meaning initial state, restart async read,
 * probably for the first time when populating a receive buffer.
 * If read status indicate not busy and a status, restart the async
 * DMA read.
 */
static int sgdma_async_read(struct altera_tse_private *priv)
{ … }

static int sgdma_async_write(struct altera_tse_private *priv,
			     struct sgdma_descrip __iomem *desc)
{ … }

static dma_addr_t
sgdma_txphysaddr(struct altera_tse_private *priv,
		 struct sgdma_descrip __iomem *desc)
{ … }

static dma_addr_t
sgdma_rxphysaddr(struct altera_tse_private *priv,
		 struct sgdma_descrip __iomem *desc)
{ … }

#define list_remove_head(list, entry, type, member) …

#define list_peek_head(list, entry, type, member) …

/* adds a tse_buffer to the tail of a tx buffer list.
 * assumes the caller is managing and holding a mutual exclusion
 * primitive to avoid simultaneous pushes/pops to the list.
 */
static void
queue_tx(struct altera_tse_private *priv, struct tse_buffer *buffer)
{ … }


/* adds a tse_buffer to the tail of a rx buffer list
 * assumes the caller is managing and holding a mutual exclusion
 * primitive to avoid simultaneous pushes/pops to the list.
 */
static void
queue_rx(struct altera_tse_private *priv, struct tse_buffer *buffer)
{ … }

/* dequeues a tse_buffer from the transmit buffer list, otherwise
 * returns NULL if empty.
 * assumes the caller is managing and holding a mutual exclusion
 * primitive to avoid simultaneous pushes/pops to the list.
 */
static struct tse_buffer *
dequeue_tx(struct altera_tse_private *priv)
{ … }

/* dequeues a tse_buffer from the receive buffer list, otherwise
 * returns NULL if empty
 * assumes the caller is managing and holding a mutual exclusion
 * primitive to avoid simultaneous pushes/pops to the list.
 */
static struct tse_buffer *
dequeue_rx(struct altera_tse_private *priv)
{ … }

/* dequeues a tse_buffer from the receive buffer list, otherwise
 * returns NULL if empty
 * assumes the caller is managing and holding a mutual exclusion
 * primitive to avoid simultaneous pushes/pops to the list while the
 * head is being examined.
 */
static struct tse_buffer *
queue_rx_peekhead(struct altera_tse_private *priv)
{ … }

/* check and return rx sgdma status without polling
 */
static int sgdma_rxbusy(struct altera_tse_private *priv)
{ … }

/* waits for the tx sgdma to finish it's current operation, returns 0
 * when it transitions to nonbusy, returns 1 if the operation times out
 */
static int sgdma_txbusy(struct altera_tse_private *priv)
{ … }
linux/drivers/net/ethernet/altera/altera_sgdma.c
