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git.ipfire.org Git - thirdparty/u-boot.git/blob - common/bouncebuf.c
1 // SPDX-License-Identifier: GPL-2.0+
3 * Generic bounce buffer implementation
5 * Copyright (C) 2012 Marek Vasut <marex@denx.de>
11 #include <bouncebuf.h>
13 static int addr_aligned(struct bounce_buffer
*state
)
15 const ulong align_mask
= ARCH_DMA_MINALIGN
- 1;
17 /* Check if start is aligned */
18 if ((ulong
)state
->user_buffer
& align_mask
) {
19 debug("Unaligned buffer address %p\n", state
->user_buffer
);
23 /* Check if length is aligned */
24 if (state
->len
!= state
->len_aligned
) {
25 debug("Unaligned buffer length %zu\n", state
->len
);
33 int bounce_buffer_start(struct bounce_buffer
*state
, void *data
,
34 size_t len
, unsigned int flags
)
36 state
->user_buffer
= data
;
37 state
->bounce_buffer
= data
;
39 state
->len_aligned
= roundup(len
, ARCH_DMA_MINALIGN
);
42 if (!addr_aligned(state
)) {
43 state
->bounce_buffer
= memalign(ARCH_DMA_MINALIGN
,
45 if (!state
->bounce_buffer
)
48 if (state
->flags
& GEN_BB_READ
)
49 memcpy(state
->bounce_buffer
, state
->user_buffer
,
54 * Flush data to RAM so DMA reads can pick it up,
55 * and any CPU writebacks don't race with DMA writes
57 flush_dcache_range((unsigned long)state
->bounce_buffer
,
58 (unsigned long)(state
->bounce_buffer
) +
64 int bounce_buffer_stop(struct bounce_buffer
*state
)
66 if (state
->flags
& GEN_BB_WRITE
) {
67 /* Invalidate cache so that CPU can see any newly DMA'd data */
68 invalidate_dcache_range((unsigned long)state
->bounce_buffer
,
69 (unsigned long)(state
->bounce_buffer
) +
73 if (state
->bounce_buffer
== state
->user_buffer
)
76 if (state
->flags
& GEN_BB_WRITE
)
77 memcpy(state
->user_buffer
, state
->bounce_buffer
, state
->len
);
79 free(state
->bounce_buffer
);