linux/drivers/misc/mei/dma-ring.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright(c) 2016-2018 Intel Corporation. All rights reserved.
 */
#include <linux/dma-mapping.h>
#include <linux/mei.h>

#include "mei_dev.h"

/**
 * mei_dmam_dscr_alloc() - allocate a managed coherent buffer
 *     for the dma descriptor
 * @dev: mei_device
 * @dscr: dma descriptor
 *
 * Return:
 * * 0       - on success or zero allocation request
 * * -EINVAL - if size is not power of 2
 * * -ENOMEM - of allocation has failed
 */
static int mei_dmam_dscr_alloc(struct mei_device *dev,
			       struct mei_dma_dscr *dscr)
{ … }

/**
 * mei_dmam_dscr_free() - free a managed coherent buffer
 *     from the dma descriptor
 * @dev: mei_device
 * @dscr: dma descriptor
 */
static void mei_dmam_dscr_free(struct mei_device *dev,
			       struct mei_dma_dscr *dscr)
{ … }

/**
 * mei_dmam_ring_free() - free dma ring buffers
 * @dev: mei device
 */
void mei_dmam_ring_free(struct mei_device *dev)
{ … }

/**
 * mei_dmam_ring_alloc() - allocate dma ring buffers
 * @dev: mei device
 *
 * Return: -ENOMEM on allocation failure 0 otherwise
 */
int mei_dmam_ring_alloc(struct mei_device *dev)
{ … }

/**
 * mei_dma_ring_is_allocated() - check if dma ring is allocated
 * @dev: mei device
 *
 * Return: true if dma ring is allocated
 */
bool mei_dma_ring_is_allocated(struct mei_device *dev)
{ … }

static inline
struct hbm_dma_ring_ctrl *mei_dma_ring_ctrl(struct mei_device *dev)
{ … }

/**
 * mei_dma_ring_reset() - reset the dma control block
 * @dev: mei device
 */
void mei_dma_ring_reset(struct mei_device *dev)
{ … }

/**
 * mei_dma_copy_from() - copy from dma ring into buffer
 * @dev: mei device
 * @buf: data buffer
 * @offset: offset in slots.
 * @n: number of slots to copy.
 *
 * Return: number of bytes copied
 */
static size_t mei_dma_copy_from(struct mei_device *dev, unsigned char *buf,
				u32 offset, u32 n)
{ … }

/**
 * mei_dma_copy_to() - copy to a buffer to the dma ring
 * @dev: mei device
 * @buf: data buffer
 * @offset: offset in slots.
 * @n: number of slots to copy.
 *
 * Return: number of bytes copied
 */
static size_t mei_dma_copy_to(struct mei_device *dev, unsigned char *buf,
			      u32 offset, u32 n)
{ … }

/**
 * mei_dma_ring_read() - read data from the ring
 * @dev: mei device
 * @buf: buffer to read into: may be NULL in case of dropping the data.
 * @len: length to read.
 */
void mei_dma_ring_read(struct mei_device *dev, unsigned char *buf, u32 len)
{ … }

static inline u32 mei_dma_ring_hbuf_depth(struct mei_device *dev)
{ … }

/**
 * mei_dma_ring_empty_slots() - calaculate number of empty slots in dma ring
 * @dev: mei_device
 *
 * Return: number of empty slots
 */
u32 mei_dma_ring_empty_slots(struct mei_device *dev)
{ … }

/**
 * mei_dma_ring_write - write data to dma ring host buffer
 *
 * @dev: mei_device
 * @buf: data will be written
 * @len: data length
 */
void mei_dma_ring_write(struct mei_device *dev, unsigned char *buf, u32 len)
{ … }