diff options
| -rw-r--r-- | common/Makefile | 1 | ||||
| -rw-r--r-- | common/bouncebuf.c | 92 | ||||
| -rw-r--r-- | include/bouncebuf.h | 87 |
3 files changed, 180 insertions, 0 deletions
diff --git a/common/Makefile b/common/Makefile index fdfead79c..2e3b22311 100644 --- a/common/Makefile +++ b/common/Makefile @@ -204,6 +204,7 @@ COBJS-$(CONFIG_SPL_NET_SUPPORT) += env_common.o COBJS-$(CONFIG_SPL_NET_SUPPORT) += env_nowhere.o COBJS-$(CONFIG_SPL_NET_SUPPORT) += miiphyutil.o endif +COBJS-$(CONFIG_BOUNCE_BUFFER) += bouncebuf.o COBJS-y += console.o COBJS-y += dlmalloc.o COBJS-y += image.o diff --git a/common/bouncebuf.c b/common/bouncebuf.c new file mode 100644 index 000000000..4f827f893 --- /dev/null +++ b/common/bouncebuf.c @@ -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; +} diff --git a/include/bouncebuf.h b/include/bouncebuf.h new file mode 100644 index 000000000..31021c5b8 --- /dev/null +++ b/include/bouncebuf.h @@ -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 |