mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-18 02:38:56 +00:00
8074ffe335
Add extended version of the bounce_buffer_start(), which permits passing in a custom alignment checker function for the buffer. This is useful e.g. on systems with various DMA restrictions and where the checker function might be more complex than a simple CPU cache alignment check. Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com> Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Peng Fan <peng.fan@nxp.com> Cc: Simon Glass <sjg@chromium.org> Cc: Tom Rini <trini@konsulko.com>
86 lines
3.1 KiB
C
86 lines
3.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
|
|
/*
|
|
* Generic bounce buffer implementation
|
|
*
|
|
* Copyright (C) 2012 Marek Vasut <marex@denx.de>
|
|
*/
|
|
|
|
#ifndef __INCLUDE_BOUNCEBUF_H__
|
|
#define __INCLUDE_BOUNCEBUF_H__
|
|
|
|
#include <linux/types.h>
|
|
|
|
/*
|
|
* GEN_BB_READ -- Data are read from the buffer eg. by DMA hardware.
|
|
* The source buffer is copied into the bounce buffer (if unaligned, otherwise
|
|
* the source buffer is used directly) upon start() call, then the operation
|
|
* requiring the aligned transfer happens, then the bounce buffer is lost upon
|
|
* stop() call.
|
|
*/
|
|
#define GEN_BB_READ (1 << 0)
|
|
/*
|
|
* GEN_BB_WRITE -- Data are written into the buffer eg. by DMA hardware.
|
|
* The source buffer starts in an undefined state upon start() call, then the
|
|
* operation requiring the aligned transfer happens, then the bounce buffer is
|
|
* copied into the destination buffer (if unaligned, otherwise destination
|
|
* buffer is used directly) upon stop() call.
|
|
*/
|
|
#define GEN_BB_WRITE (1 << 1)
|
|
/*
|
|
* GEN_BB_RW -- Data are read and written into the buffer eg. by DMA hardware.
|
|
* The source buffer is copied into the bounce buffer (if unaligned, otherwise
|
|
* the source buffer is used directly) upon start() call, then the operation
|
|
* requiring the aligned transfer happens, then the bounce buffer is copied
|
|
* into the destination buffer (if unaligned, otherwise destination buffer is
|
|
* used directly) upon stop() call.
|
|
*/
|
|
#define GEN_BB_RW (GEN_BB_READ | GEN_BB_WRITE)
|
|
|
|
struct bounce_buffer {
|
|
/* Copy of data parameter passed to start() */
|
|
void *user_buffer;
|
|
/*
|
|
* DMA-aligned buffer. This field is always set to the value that
|
|
* should be used for DMA; either equal to .user_buffer, or to a
|
|
* freshly allocated aligned buffer.
|
|
*/
|
|
void *bounce_buffer;
|
|
/* Copy of len parameter passed to start() */
|
|
size_t len;
|
|
/* DMA-aligned buffer length */
|
|
size_t len_aligned;
|
|
/* Copy of flags parameter passed to start() */
|
|
unsigned int flags;
|
|
};
|
|
|
|
/**
|
|
* bounce_buffer_start() -- Start the bounce buffer session
|
|
* state: stores state passed between bounce_buffer_{start,stop}
|
|
* data: pointer to buffer to be aligned
|
|
* len: length of the buffer
|
|
* flags: flags describing the transaction, see above.
|
|
*/
|
|
int bounce_buffer_start(struct bounce_buffer *state, void *data,
|
|
size_t len, unsigned int flags);
|
|
|
|
/**
|
|
* bounce_buffer_start() -- Start the bounce buffer session with external align check function
|
|
* state: stores state passed between bounce_buffer_{start,stop}
|
|
* data: pointer to buffer to be aligned
|
|
* len: length of the buffer
|
|
* flags: flags describing the transaction, see above.
|
|
* alignment: alignment of the newly allocated bounce buffer
|
|
* addr_is_aligned: function for checking the alignment instead of the default one
|
|
*/
|
|
int bounce_buffer_start_extalign(struct bounce_buffer *state, void *data,
|
|
size_t len, unsigned int flags,
|
|
size_t alignment,
|
|
int (*addr_is_aligned)(struct bounce_buffer *state));
|
|
|
|
/**
|
|
* bounce_buffer_stop() -- Finish the bounce buffer session
|
|
* state: stores state passed between bounce_buffer_{start,stop}
|
|
*/
|
|
int bounce_buffer_stop(struct bounce_buffer *state);
|
|
|
|
#endif
|