1 /* $NetBSD: ttm_bus_dma.c,v 1.10 2021/12/19 11:32:54 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2014 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: ttm_bus_dma.c,v 1.10 2021/12/19 11:32:54 riastradh Exp $");
34
35 #include <sys/bus.h>
36
37 #include <uvm/uvm_extern.h>
38
39 #include <drm/bus_dma_hacks.h>
40 #include <ttm/ttm_bo_driver.h>
41 #include <ttm/ttm_page_alloc.h>
42
43 /*
44 * ttm_bus_dma_populate(ttm_dma)
45 *
46 * If ttm_dma is not already populated, wire its pages and load
47 * its DMA map. The wiring and loading are stable as long as the
48 * associated bo is reserved.
49 *
50 * Transitions from tt_unpopulated to tt_unbound. Marks as wired,
51 * a.k.a. !swapped.
52 */
53 int
ttm_bus_dma_populate(struct ttm_dma_tt * ttm_dma)54 ttm_bus_dma_populate(struct ttm_dma_tt *ttm_dma)
55 {
56 int ret;
57
58 KASSERT(ttm_dma->ttm.state == tt_unpopulated);
59
60 /* If it's unpopulated, it can't be swapped. */
61 KASSERT(!ISSET(ttm_dma->ttm.page_flags, TTM_PAGE_FLAG_SWAPPED));
62 /* Pretend it is now, for the sake of ttm_tt_wire. */
63 ttm_dma->ttm.page_flags |= TTM_PAGE_FLAG_SWAPPED;
64
65 /* Wire the uvm pages and fill the ttm page array. */
66 ret = ttm_tt_wire(&ttm_dma->ttm);
67 if (ret)
68 goto fail0;
69
70 /* Mark it populated but unbound. */
71 ttm_dma->ttm.state = tt_unbound;
72
73 /* Mark it wired. */
74 ttm_dma->ttm.page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
75
76 /* Load the DMA map. */
77 /* XXX errno NetBSD->Linux */
78 ret = -bus_dmamap_load_pages(ttm_dma->ttm.bdev->dmat,
79 ttm_dma->dma_address, ttm_dma->ttm.pages,
80 (ttm_dma->ttm.num_pages << PAGE_SHIFT), BUS_DMA_NOWAIT);
81 if (ret)
82 goto fail1;
83
84 /* Success! */
85 return 0;
86
87 fail2: __unused
88 bus_dmamap_unload(ttm_dma->ttm.bdev->dmat, ttm_dma->dma_address);
89 fail1: KASSERT(ttm_dma->ttm.state == tt_unbound);
90 ttm_tt_unwire(&ttm_dma->ttm);
91 ttm_dma->ttm.state = tt_unpopulated;
92 fail0: KASSERT(ret);
93 return ret;
94 }
95
96 static void
ttm_bus_dma_put(struct ttm_dma_tt * ttm_dma,int flags)97 ttm_bus_dma_put(struct ttm_dma_tt *ttm_dma, int flags)
98 {
99 struct uvm_object *const uobj = ttm_dma->ttm.swap_storage;
100 const size_t size = (ttm_dma->ttm.num_pages << PAGE_SHIFT);
101
102 /*
103 * Can't be tt_bound -- still in use and needs to be removed
104 * from GPU page tables. Can't be tt_unpopulated -- if it
105 * were, why are you hnadling this? Hence tt_unbound.
106 */
107 KASSERTMSG((ttm_dma->ttm.state == tt_unbound),
108 "ttm_tt %p in invalid state for unpopulate/swapout: %d",
109 &ttm_dma->ttm, (int)ttm_dma->ttm.state);
110
111 /* If pages are wired and loaded, unload and unwire them. */
112 if (!ISSET(ttm_dma->ttm.page_flags, TTM_PAGE_FLAG_SWAPPED)) {
113 bus_dmamap_unload(ttm_dma->ttm.bdev->dmat,
114 ttm_dma->dma_address);
115 ttm_tt_unwire(&ttm_dma->ttm);
116 ttm_dma->ttm.page_flags |= TTM_PAGE_FLAG_SWAPPED;
117 }
118
119 /* We are using uvm_aobj, which had better have a pgo_put. */
120 KASSERT(uobj->pgops->pgo_put);
121
122 /* Release or deactivate the pages. */
123 rw_enter(uobj->vmobjlock, RW_WRITER);
124 (void)(*uobj->pgops->pgo_put)(uobj, 0, size, flags);
125 /* pgo_put unlocks uobj->vmobjlock. */
126
127 /* Mark it unpopulated. */
128 ttm_dma->ttm.state = tt_unpopulated;
129 }
130
131 /*
132 * ttmm_bus_dma_unpopulate(ttm_dma)
133 *
134 * Unload any DMA map, unwire any pages, and release any pages
135 * associated with ttm_dma.
136 *
137 * Transitions from tt_unbound to tt_unpopulated. Marks as
138 * unwired, a.k.a. swapped.
139 */
140 void
ttm_bus_dma_unpopulate(struct ttm_dma_tt * ttm_dma)141 ttm_bus_dma_unpopulate(struct ttm_dma_tt *ttm_dma)
142 {
143
144 ttm_bus_dma_put(ttm_dma, PGO_CLEANIT|PGO_FREE);
145 }
146
147 /*
148 * ttm_bus_dma_swapout(ttm_dma)
149 *
150 * Unload any DMA map, unwire any pages, and deactivate any pages
151 * associated with ttm_dma so that they can be swapped out, but
152 * don't release them.
153 *
154 * Transitions from tt_unbound to tt_unpopulated. Marks as
155 * unwired, a.k.a. swapped.
156 */
157 void
ttm_bus_dma_swapout(struct ttm_dma_tt * ttm_dma)158 ttm_bus_dma_swapout(struct ttm_dma_tt *ttm_dma)
159 {
160
161 ttm_bus_dma_put(ttm_dma, PGO_DEACTIVATE);
162 }
163