Implement common bounce buffer to be used on a less capable hardware. That includes hardware that can not do DMA from any address or such. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Fabio Estevam <festevam@gmail.com> Cc: Andy Fleming <afleming@freescale.com> Signed-off-by: Andy Fleming <afleming@freescale.com>master
parent
99070db0dc
commit
b660df3c90
@ -0,0 +1,92 @@ |
|||||||
|
/*
|
||||||
|
* Generic bounce buffer implementation |
||||||
|
* |
||||||
|
* Copyright (C) 2012 Marek Vasut <marex@denx.de> |
||||||
|
* |
||||||
|
* See file CREDITS for list of people who contributed to this |
||||||
|
* project. |
||||||
|
* |
||||||
|
* This program is free software; you can redistribute it and/or |
||||||
|
* modify it under the terms of the GNU General Public License as |
||||||
|
* published by the Free Software Foundation; either version 2 of |
||||||
|
* the License, or (at your option) any later version. |
||||||
|
* |
||||||
|
* This program is distributed in the hope that it will be useful, |
||||||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
||||||
|
* GNU General Public License for more details. |
||||||
|
* |
||||||
|
* You should have received a copy of the GNU General Public License |
||||||
|
* along with this program; if not, write to the Free Software |
||||||
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
||||||
|
* MA 02111-1307 USA |
||||||
|
*/ |
||||||
|
|
||||||
|
#include <common.h> |
||||||
|
#include <malloc.h> |
||||||
|
#include <errno.h> |
||||||
|
#include <bouncebuf.h> |
||||||
|
|
||||||
|
static int addr_aligned(void *data, size_t len) |
||||||
|
{ |
||||||
|
const ulong align_mask = ARCH_DMA_MINALIGN - 1; |
||||||
|
|
||||||
|
/* Check if start is aligned */ |
||||||
|
if ((ulong)data & align_mask) { |
||||||
|
debug("Unaligned start address %p\n", data); |
||||||
|
return 0; |
||||||
|
} |
||||||
|
|
||||||
|
data += len; |
||||||
|
|
||||||
|
/* Check if end is aligned */ |
||||||
|
if ((ulong)data & align_mask) { |
||||||
|
debug("Unaligned end address %p\n", data); |
||||||
|
return 0; |
||||||
|
} |
||||||
|
|
||||||
|
/* Aligned */ |
||||||
|
return 1; |
||||||
|
} |
||||||
|
|
||||||
|
int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags) |
||||||
|
{ |
||||||
|
void *tmp; |
||||||
|
size_t alen; |
||||||
|
|
||||||
|
if (addr_aligned(*data, len)) { |
||||||
|
*backup = NULL; |
||||||
|
return 0; |
||||||
|
} |
||||||
|
|
||||||
|
alen = roundup(len, ARCH_DMA_MINALIGN); |
||||||
|
tmp = memalign(ARCH_DMA_MINALIGN, alen); |
||||||
|
|
||||||
|
if (!tmp) |
||||||
|
return -ENOMEM; |
||||||
|
|
||||||
|
if (flags & GEN_BB_READ) |
||||||
|
memcpy(tmp, *data, len); |
||||||
|
|
||||||
|
*backup = *data; |
||||||
|
*data = tmp; |
||||||
|
|
||||||
|
return 0; |
||||||
|
} |
||||||
|
|
||||||
|
int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags) |
||||||
|
{ |
||||||
|
void *tmp = *data; |
||||||
|
|
||||||
|
/* The buffer was already aligned, since "backup" is NULL. */ |
||||||
|
if (!*backup) |
||||||
|
return 0; |
||||||
|
|
||||||
|
if (flags & GEN_BB_WRITE) |
||||||
|
memcpy(*backup, *data, len); |
||||||
|
|
||||||
|
*data = *backup; |
||||||
|
free(tmp); |
||||||
|
|
||||||
|
return 0; |
||||||
|
} |
@ -0,0 +1,87 @@ |
|||||||
|
/*
|
||||||
|
* Generic bounce buffer implementation |
||||||
|
* |
||||||
|
* Copyright (C) 2012 Marek Vasut <marex@denx.de> |
||||||
|
* |
||||||
|
* See file CREDITS for list of people who contributed to this |
||||||
|
* project. |
||||||
|
* |
||||||
|
* This program is free software; you can redistribute it and/or |
||||||
|
* modify it under the terms of the GNU General Public License as |
||||||
|
* published by the Free Software Foundation; either version 2 of |
||||||
|
* the License, or (at your option) any later version. |
||||||
|
* |
||||||
|
* This program is distributed in the hope that it will be useful, |
||||||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
||||||
|
* GNU General Public License for more details. |
||||||
|
* |
||||||
|
* You should have received a copy of the GNU General Public License |
||||||
|
* along with this program; if not, write to the Free Software |
||||||
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
||||||
|
* MA 02111-1307 USA |
||||||
|
*/ |
||||||
|
|
||||||
|
#ifndef __INCLUDE_BOUNCEBUF_H__ |
||||||
|
#define __INCLUDE_BOUNCEBUF_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) |
||||||
|
|
||||||
|
#ifdef CONFIG_BOUNCE_BUFFER |
||||||
|
/**
|
||||||
|
* bounce_buffer_start() -- Start the bounce buffer session |
||||||
|
* data: pointer to buffer to be aligned |
||||||
|
* len: length of the buffer |
||||||
|
* backup: pointer to backup buffer (the original value is stored here if |
||||||
|
* needed |
||||||
|
* flags: flags describing the transaction, see above. |
||||||
|
*/ |
||||||
|
int bounce_buffer_start(void **data, size_t len, void **backup, uint8_t flags); |
||||||
|
/**
|
||||||
|
* bounce_buffer_stop() -- Finish the bounce buffer session |
||||||
|
* data: pointer to buffer that was aligned |
||||||
|
* len: length of the buffer |
||||||
|
* backup: pointer to backup buffer (the original value is stored here if |
||||||
|
* needed |
||||||
|
* flags: flags describing the transaction, see above. |
||||||
|
*/ |
||||||
|
int bounce_buffer_stop(void **data, size_t len, void **backup, uint8_t flags); |
||||||
|
#else |
||||||
|
static inline int bounce_buffer_start(void **data, size_t len, void **backup, |
||||||
|
uint8_t flags) |
||||||
|
{ |
||||||
|
return 0; |
||||||
|
} |
||||||
|
|
||||||
|
static inline int bounce_buffer_stop(void **data, size_t len, void **backup, |
||||||
|
uint8_t flags) |
||||||
|
{ |
||||||
|
return 0; |
||||||
|
} |
||||||
|
#endif |
||||||
|
|
||||||
|
#endif |
Loading…
Reference in new issue