xref: /freebsd/sys/dev/hyperv/vmbus/hyperv_busdma.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * Copyright (c) 2016 Microsoft Corp.
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  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. 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  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 
34 #include <machine/bus.h>
35 
36 #include <dev/hyperv/include/hyperv_busdma.h>
37 
38 #define HYPERV_DMA_MASK	(BUS_DMA_WAITOK | BUS_DMA_NOWAIT | BUS_DMA_ZERO)
39 
40 void
41 hyperv_dma_map_paddr(void *arg, bus_dma_segment_t *segs, int nseg, int error)
42 {
43 	bus_addr_t *paddr = arg;
44 
45 	if (error)
46 		return;
47 
48 	KASSERT(nseg == 1, ("too many segments %d!", nseg));
49 	*paddr = segs->ds_addr;
50 }
51 
52 void *
53 hyperv_dmamem_alloc(bus_dma_tag_t parent_dtag, bus_size_t alignment,
54     bus_addr_t boundary, bus_size_t size, struct hyperv_dma *dma, int flags)
55 {
56 	void *ret;
57 	int error;
58 
59 	error = bus_dma_tag_create(parent_dtag, /* parent */
60 	    alignment,		/* alignment */
61 	    boundary,		/* boundary */
62 	    BUS_SPACE_MAXADDR,	/* lowaddr */
63 	    BUS_SPACE_MAXADDR,	/* highaddr */
64 	    NULL, NULL,		/* filter, filterarg */
65 	    size,		/* maxsize */
66 	    1,			/* nsegments */
67 	    size,		/* maxsegsize */
68 	    0,			/* flags */
69 	    NULL,		/* lockfunc */
70 	    NULL,		/* lockfuncarg */
71 	    &dma->hv_dtag);
72 	if (error)
73 		return NULL;
74 
75 	error = bus_dmamem_alloc(dma->hv_dtag, &ret,
76 	    (flags & HYPERV_DMA_MASK) | BUS_DMA_COHERENT, &dma->hv_dmap);
77 	if (error) {
78 		bus_dma_tag_destroy(dma->hv_dtag);
79 		return NULL;
80 	}
81 
82 	error = bus_dmamap_load(dma->hv_dtag, dma->hv_dmap, ret, size,
83 	    hyperv_dma_map_paddr, &dma->hv_paddr, BUS_DMA_NOWAIT);
84 	if (error) {
85 		bus_dmamem_free(dma->hv_dtag, ret, dma->hv_dmap);
86 		bus_dma_tag_destroy(dma->hv_dtag);
87 		return NULL;
88 	}
89 	return ret;
90 }
91 
92 void
93 hyperv_dmamem_free(struct hyperv_dma *dma, void *ptr)
94 {
95 	bus_dmamap_unload(dma->hv_dtag, dma->hv_dmap);
96 	bus_dmamem_free(dma->hv_dtag, ptr, dma->hv_dmap);
97 	bus_dma_tag_destroy(dma->hv_dtag);
98 }
99