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- // 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 <malloc.h>
- #include <errno.h>
- #include <bouncebuf.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;
- }
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