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82 lines
1.9 KiB
82 lines
1.9 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Generic bounce buffer implementation |
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* |
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* Copyright (C) 2012 Marek Vasut <[email protected]> |
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*/ |
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#include <common.h> |
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#include <malloc.h> |
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#include <errno.h> |
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#include <bouncebuf.h> |
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static int addr_aligned(struct bounce_buffer *state) |
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{ |
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const ulong align_mask = ARCH_DMA_MINALIGN - 1; |
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/* Check if start is aligned */ |
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if ((ulong)state->user_buffer & align_mask) { |
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debug("Unaligned buffer address %p\n", state->user_buffer); |
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return 0; |
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} |
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/* Check if length is aligned */ |
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if (state->len != state->len_aligned) { |
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debug("Unaligned buffer length %zu\n", state->len); |
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return 0; |
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} |
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/* Aligned */ |
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return 1; |
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} |
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int bounce_buffer_start(struct bounce_buffer *state, void *data, |
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size_t len, unsigned int flags) |
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{ |
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state->user_buffer = data; |
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state->bounce_buffer = data; |
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state->len = len; |
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state->len_aligned = roundup(len, ARCH_DMA_MINALIGN); |
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state->flags = flags; |
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if (!addr_aligned(state)) { |
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state->bounce_buffer = memalign(ARCH_DMA_MINALIGN, |
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state->len_aligned); |
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if (!state->bounce_buffer) |
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return -ENOMEM; |
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if (state->flags & GEN_BB_READ) |
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memcpy(state->bounce_buffer, state->user_buffer, |
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state->len); |
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} |
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/* |
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* Flush data to RAM so DMA reads can pick it up, |
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* and any CPU writebacks don't race with DMA writes |
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*/ |
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flush_dcache_range((unsigned long)state->bounce_buffer, |
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(unsigned long)(state->bounce_buffer) + |
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state->len_aligned); |
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return 0; |
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} |
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int bounce_buffer_stop(struct bounce_buffer *state) |
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{ |
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if (state->flags & GEN_BB_WRITE) { |
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/* Invalidate cache so that CPU can see any newly DMA'd data */ |
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invalidate_dcache_range((unsigned long)state->bounce_buffer, |
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(unsigned long)(state->bounce_buffer) + |
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state->len_aligned); |
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} |
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if (state->bounce_buffer == state->user_buffer) |
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return 0; |
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if (state->flags & GEN_BB_WRITE) |
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memcpy(state->user_buffer, state->bounce_buffer, state->len); |
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free(state->bounce_buffer); |
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return 0; |
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}
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