| 1 | /*
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| 2 | * Copyright (c) 2017 Ondrej Hlavaty <aearsis@eideo.cz>
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 | /** @addtogroup libusb
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| 29 | * @{
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| 30 | */
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| 31 | /** @file
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| 32 | * @brief USB host controller library: DMA buffer helpers
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| 33 | *
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| 34 | * Simplifies usage of bounce buffers
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| 35 | *
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| 36 | * Currently the minimum size allocated is a page, which is wasteful. Could be
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| 37 | * extended to support memory pools, which will enable smaller units of
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| 38 | * allocation.
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| 39 | */
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| 40 | #ifndef LIB_USB_DMA_BUFFER
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| 41 | #define LIB_USB_DMA_BUFFER
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| 42 |
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| 43 | #include <stdint.h>
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| 44 | #include <stdlib.h>
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| 45 | #include <errno.h>
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| 46 |
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| 47 | typedef const struct dma_policy {
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| 48 | unsigned flags;
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| 49 |
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| 50 | #define DMA_POLICY_F_4GiB (1<<0) /**< Must use only 32-bit addresses */
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| 51 | #define DMA_POLICY_F_CONTIGUOUS (1<<1) /**< Pages must follow each other physically */
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| 52 | } dma_policy_t;
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| 53 |
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| 54 | typedef struct dma_buffer {
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| 55 | void *virt;
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| 56 | uintptr_t phys;
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| 57 | } dma_buffer_t;
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| 58 |
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| 59 | extern int dma_buffer_alloc(dma_buffer_t *db, size_t size);
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| 60 | extern int dma_buffer_alloc_policy(dma_buffer_t *, size_t, dma_policy_t *);
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| 61 | extern void dma_buffer_free(dma_buffer_t *);
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| 62 | extern uintptr_t dma_buffer_phys(const dma_buffer_t *, void *);
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| 63 |
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| 64 | extern bool dma_buffer_check_policy(const void *, size_t, dma_policy_t *);
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| 65 |
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| 66 | static inline int dma_buffer_is_set(dma_buffer_t *db)
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| 67 | {
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| 68 | return !!db->virt;
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| 69 | }
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| 70 |
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| 71 | #endif
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| 72 | /**
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| 73 | * @}
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| 74 | */
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