linux/drivers/misc/cb710/sgbuf2.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  cb710/sgbuf2.c
 *
 *  Copyright by Michał Mirosław, 2008-2009
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cb710.h>

static bool sg_dwiter_next(struct sg_mapping_iter *miter)
{ … }

static bool sg_dwiter_is_at_end(struct sg_mapping_iter *miter)
{ … }

static uint32_t sg_dwiter_read_buffer(struct sg_mapping_iter *miter)
{ … }

static inline bool needs_unaligned_copy(const void *ptr)
{ … }

static bool sg_dwiter_get_next_block(struct sg_mapping_iter *miter, uint32_t **ptr)
{ … }

/**
 * cb710_sg_dwiter_read_next_block() - get next 32-bit word from sg buffer
 * @miter: sg mapping iterator used for reading
 *
 * Description:
 *   Returns 32-bit word starting at byte pointed to by @miter@
 *   handling any alignment issues.  Bytes past the buffer's end
 *   are not accessed (read) but are returned as zeroes.  @miter@
 *   is advanced by 4 bytes or to the end of buffer whichever is
 *   closer.
 *
 * Context:
 *   Same requirements as in sg_miter_next().
 *
 * Returns:
 *   32-bit word just read.
 */
uint32_t cb710_sg_dwiter_read_next_block(struct sg_mapping_iter *miter)
{ … }
EXPORT_SYMBOL_GPL(…);

static void sg_dwiter_write_slow(struct sg_mapping_iter *miter, uint32_t data)
{ … }

/**
 * cb710_sg_dwiter_write_next_block() - write next 32-bit word to sg buffer
 * @miter: sg mapping iterator used for writing
 * @data: data to write to sg buffer
 *
 * Description:
 *   Writes 32-bit word starting at byte pointed to by @miter@
 *   handling any alignment issues.  Bytes which would be written
 *   past the buffer's end are silently discarded. @miter@ is
 *   advanced by 4 bytes or to the end of buffer whichever is closer.
 *
 * Context:
 *   Same requirements as in sg_miter_next().
 */
void cb710_sg_dwiter_write_next_block(struct sg_mapping_iter *miter, uint32_t data)
{ … }
EXPORT_SYMBOL_GPL(…);