source: mainline/uspace/lib/usbhost/include/usb/host/dma_buffer.h@ 4c25c2fb

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 4c25c2fb was 35c37fc, checked in by Ondřej Hlavatý <aearsis@…>, 7 years ago

ehci: refactor to dma_buffers

One big hidden thing was refactored - now TDs are allocated in one
buffer together with setup and data buffers themselves. This reduces the
number of allocated pages per transfer to minimum.

  • Property mode set to 100644
File size: 2.5 KB
Line 
1/*
2 * Copyright (c) 2017 Ondrej Hlavaty <aearsis@eideo.cz>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28/** @addtogroup drvusbehci
29 * @{
30 */
31/** @file
32 * @brief USB host controller library: DMA buffer helpers
33 *
34 * Simplifies usage of bounce buffers.
35 *
36 * Currently the minimum size allocated is a page, which is wasteful. Could be
37 * extended to support memory pools, which will enable smaller units of
38 * allocation.
39 */
40#ifndef LIB_USBHOST_DMA_BUFFER
41#define LIB_USBHOST_DMA_BUFFER
42
43#include <stdint.h>
44#include <stdlib.h>
45#include <errno.h>
46
47typedef const struct dma_policy {
48 bool use64; /**< Whether to use more than initial 4GiB of memory */
49 size_t alignment; /**< What alignment is needed. At most PAGE_SIZE. */
50} dma_policy_t;
51
52typedef struct dma_buffer {
53 void *virt;
54 uintptr_t phys;
55} dma_buffer_t;
56
57extern dma_policy_t dma_policy_default;
58
59extern int dma_buffer_alloc(dma_buffer_t *db, size_t size);
60extern int dma_buffer_alloc_policy(dma_buffer_t *, size_t, dma_policy_t);
61extern void dma_buffer_free(dma_buffer_t *);
62extern uintptr_t dma_buffer_phys(const dma_buffer_t *, void *);
63
64static inline int dma_buffer_is_set(dma_buffer_t *db)
65{
66 return !!db->virt;
67}
68
69#endif
70/**
71 * @}
72 */
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