diff options
Diffstat (limited to 'roms/u-boot/common/bouncebuf.c')
-rw-r--r-- | roms/u-boot/common/bouncebuf.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/roms/u-boot/common/bouncebuf.c b/roms/u-boot/common/bouncebuf.c new file mode 100644 index 000000000..6d98920de --- /dev/null +++ b/roms/u-boot/common/bouncebuf.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Generic bounce buffer implementation + * + * Copyright (C) 2012 Marek Vasut <marex@denx.de> + */ + +#include <common.h> +#include <cpu_func.h> +#include <log.h> +#include <malloc.h> +#include <errno.h> +#include <bouncebuf.h> +#include <asm/cache.h> + +static int addr_aligned(struct bounce_buffer *state) +{ + const ulong align_mask = ARCH_DMA_MINALIGN - 1; + + /* Check if start is aligned */ + if ((ulong)state->user_buffer & align_mask) { + debug("Unaligned buffer address %p\n", state->user_buffer); + return 0; + } + + /* Check if length is aligned */ + if (state->len != state->len_aligned) { + debug("Unaligned buffer length %zu\n", state->len); + return 0; + } + + /* Aligned */ + return 1; +} + +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)) +{ + state->user_buffer = data; + state->bounce_buffer = data; + state->len = len; + state->len_aligned = roundup(len, alignment); + state->flags = flags; + + if (!addr_is_aligned(state)) { + state->bounce_buffer = memalign(alignment, + state->len_aligned); + if (!state->bounce_buffer) + return -ENOMEM; + + if (state->flags & GEN_BB_READ) + memcpy(state->bounce_buffer, state->user_buffer, + state->len); + } + + /* + * Flush data to RAM so DMA reads can pick it up, + * and any CPU writebacks don't race with DMA writes + */ + flush_dcache_range((unsigned long)state->bounce_buffer, + (unsigned long)(state->bounce_buffer) + + state->len_aligned); + + return 0; +} + +int bounce_buffer_start(struct bounce_buffer *state, void *data, + size_t len, unsigned int flags) +{ + return bounce_buffer_start_extalign(state, data, len, flags, + ARCH_DMA_MINALIGN, + addr_aligned); +} + +int bounce_buffer_stop(struct bounce_buffer *state) +{ + if (state->flags & GEN_BB_WRITE) { + /* Invalidate cache so that CPU can see any newly DMA'd data */ + invalidate_dcache_range((unsigned long)state->bounce_buffer, + (unsigned long)(state->bounce_buffer) + + state->len_aligned); + } + + if (state->bounce_buffer == state->user_buffer) + return 0; + + if (state->flags & GEN_BB_WRITE) + memcpy(state->user_buffer, state->bounce_buffer, state->len); + + free(state->bounce_buffer); + + return 0; +} |