1/* $NetBSD: drm_memory.c,v 1.10 2016/03/06 10:59:56 mlelstv Exp $ */
2
3/*-
4 * Copyright (c) 2013 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: drm_memory.c,v 1.10 2016/03/06 10:59:56 mlelstv Exp $");
34
35#if defined(__i386__) || defined(__x86_64__)
36
37# ifdef _KERNEL_OPT
38# include "agp.h"
39# if NAGP > 0
40# include "agp_i810.h"
41# else
42# define NAGP_I810 0
43# endif
44# include "genfb.h"
45# else
46# define NAGP_I810 1
47# define NGENFB 0
48# endif
49
50#else
51
52# ifdef _KERNEL_OPT
53# define NAGP_I810 0
54# include "genfb.h"
55# else
56# define NAGP_I810 0
57# define NGENFB 0
58# endif
59
60#endif
61
62#include <sys/bus.h>
63
64#if NAGP_I810 > 0
65/* XXX include order botch -- shouldn't need to include pcivar.h */
66#include <dev/pci/pcivar.h>
67#include <dev/pci/agpvar.h>
68#endif
69
70#if NGENFB > 0
71#include <dev/wsfb/genfbvar.h>
72#endif
73
74#include <drm/drmP.h>
75
76/*
77 * XXX drm_bus_borrow is a horrible kludge!
78 */
79static bool
80drm_bus_borrow(bus_addr_t base, bus_size_t size, bus_space_handle_t *handlep)
81{
82
83#if NAGP_I810 > 0
84 if (agp_i810_borrow(base, size, handlep))
85 return true;
86#endif
87
88#if NGENFB > 0
89 if (genfb_borrow(base, handlep))
90 return true;
91#endif
92
93 return false;
94}
95
96void
97drm_core_ioremap(struct drm_local_map *map, struct drm_device *dev)
98{
99 const bus_space_tag_t bst = dev->bst;
100 unsigned int unit;
101
102 /*
103 * Search dev's bus maps for a match.
104 */
105 for (unit = 0; unit < dev->bus_nmaps; unit++) {
106 struct drm_bus_map *const bm = &dev->bus_maps[unit];
107 int flags = bm->bm_flags;
108
109 /* Reject maps starting after the request. */
110 if (map->offset < bm->bm_base)
111 continue;
112
113 /* Reject maps smaller than the request. */
114 if (bm->bm_size < map->size)
115 continue;
116
117 /* Reject maps that the request doesn't fit in. */
118 if ((bm->bm_size - map->size) <
119 (map->offset - bm->bm_base))
120 continue;
121
122 /* Ensure we can map the space into virtual memory. */
123 if (!ISSET(flags, BUS_SPACE_MAP_LINEAR))
124 continue;
125
126 /* Reflect requested flags in the bus_space map. */
127 if (ISSET(map->flags, _DRM_WRITE_COMBINING))
128 flags |= BUS_SPACE_MAP_PREFETCHABLE;
129
130 /* Map it. */
131 if (bus_space_map(bst, map->offset, map->size, flags,
132 &map->lm_data.bus_space.bsh))
133 break;
134
135 map->lm_data.bus_space.bus_map = bm;
136 goto win;
137 }
138
139 /* Couldn't map it. Try borrowing from someone else. */
140 if (drm_bus_borrow(map->offset, map->size,
141 &map->lm_data.bus_space.bsh)) {
142 map->lm_data.bus_space.bus_map = NULL;
143 goto win;
144 }
145
146 /* Failure! */
147 return;
148
149win: map->lm_data.bus_space.bst = bst;
150 map->handle = bus_space_vaddr(bst, map->lm_data.bus_space.bsh);
151}
152
153void
154drm_core_ioremapfree(struct drm_local_map *map, struct drm_device *dev)
155{
156 if (map->lm_data.bus_space.bus_map != NULL) {
157 bus_space_unmap(map->lm_data.bus_space.bst,
158 map->lm_data.bus_space.bsh, map->size);
159 map->lm_data.bus_space.bus_map = NULL;
160 map->handle = NULL;
161 }
162}
163
164/*
165 * Allocate a drm dma handle, allocate memory fit for DMA, and map it.
166 *
167 * XXX This is called drm_pci_alloc for hysterical raisins; it is not
168 * specific to PCI.
169 *
170 * XXX For now, we use non-blocking allocations because this is called
171 * by ioctls with the drm global mutex held.
172 *
173 * XXX Error information is lost because this returns NULL on failure,
174 * not even an error embedded in a pointer.
175 */
176struct drm_dma_handle *
177drm_pci_alloc(struct drm_device *dev, size_t size, size_t align)
178{
179 int nsegs;
180 int error;
181
182 /*
183 * Allocate a drm_dma_handle record.
184 */
185 struct drm_dma_handle *const dmah = kmem_alloc(sizeof(*dmah),
186 KM_NOSLEEP);
187 if (dmah == NULL) {
188 error = -ENOMEM;
189 goto out;
190 }
191 dmah->dmah_tag = dev->dmat;
192
193 /*
194 * Allocate the requested amount of DMA-safe memory.
195 */
196 /* XXX errno NetBSD->Linux */
197 error = -bus_dmamem_alloc(dmah->dmah_tag, size, align, 0,
198 &dmah->dmah_seg, 1, &nsegs, BUS_DMA_NOWAIT);
199 if (error)
200 goto fail0;
201 KASSERT(nsegs == 1);
202
203 /*
204 * Map the DMA-safe memory into kernel virtual address space.
205 */
206 /* XXX errno NetBSD->Linux */
207 error = -bus_dmamem_map(dmah->dmah_tag, &dmah->dmah_seg, 1, size,
208 &dmah->vaddr,
209 (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE));
210 if (error)
211 goto fail1;
212 dmah->size = size;
213
214 /*
215 * Create a map for DMA transfers.
216 */
217 /* XXX errno NetBSD->Linux */
218 error = -bus_dmamap_create(dmah->dmah_tag, size, 1, size, 0,
219 BUS_DMA_NOWAIT, &dmah->dmah_map);
220 if (error)
221 goto fail2;
222
223 /*
224 * Load the kva buffer into the map for DMA transfers.
225 */
226 /* XXX errno NetBSD->Linux */
227 error = -bus_dmamap_load(dmah->dmah_tag, dmah->dmah_map, dmah->vaddr,
228 size, NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE));
229 if (error)
230 goto fail3;
231
232 /* Record the bus address for convenient reference. */
233 dmah->busaddr = dmah->dmah_map->dm_segs[0].ds_addr;
234
235 /* Zero the DMA buffer. XXX Yikes! Is this necessary? */
236 memset(dmah->vaddr, 0, size);
237
238 /* Success! */
239 return dmah;
240
241fail3: bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map);
242fail2: bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size);
243fail1: bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1);
244fail0: dmah->dmah_tag = NULL; /* XXX paranoia */
245 kmem_free(dmah, sizeof(*dmah));
246out: DRM_DEBUG("drm_pci_alloc failed: %d\n", error);
247 return NULL;
248}
249
250/*
251 * Release the bus DMA mappings and memory in dmah, and deallocate it.
252 */
253void
254drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah)
255{
256
257 bus_dmamap_unload(dmah->dmah_tag, dmah->dmah_map);
258 bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map);
259 bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size);
260 bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1);
261 dmah->dmah_tag = NULL; /* XXX paranoia */
262 kmem_free(dmah, sizeof(*dmah));
263}
264
265/*
266 * Make sure the DMA-safe memory allocated for dev lies between
267 * min_addr and max_addr. Can be used multiple times to restrict the
268 * bounds further, but never to expand the bounds again.
269 *
270 * XXX Caller must guarantee nobody has used the tag yet,
271 * i.e. allocated any DMA memory.
272 */
273int
274drm_limit_dma_space(struct drm_device *dev, resource_size_t min_addr,
275 resource_size_t max_addr)
276{
277 int ret;
278
279 KASSERT(min_addr <= max_addr);
280
281 /*
282 * Limit it further if we have already limited it, and destroy
283 * the old subregion DMA tag.
284 */
285 if (dev->dmat_subregion_p) {
286 min_addr = MAX(min_addr, dev->dmat_subregion_min);
287 max_addr = MIN(max_addr, dev->dmat_subregion_max);
288 bus_dmatag_destroy(dev->dmat);
289 }
290
291 /*
292 * Create a DMA tag for a subregion from the bus's DMA tag. If
293 * that fails, restore dev->dmat to the whole region so that we
294 * need not worry about dev->dmat being uninitialized (not that
295 * the caller should try to allocate DMA-safe memory on failure
296 * anyway, but...paranoia).
297 */
298 /* XXX errno NetBSD->Linux */
299 ret = -bus_dmatag_subregion(dev->bus_dmat, min_addr, max_addr,
300 &dev->dmat, BUS_DMA_WAITOK);
301 if (ret) {
302 dev->dmat = dev->bus_dmat;
303 dev->dmat_subregion_p = false;
304 return ret;
305 }
306
307 /*
308 * Remember that we have a subregion tag so that we know to
309 * destroy it later, and record the bounds in case we need to
310 * limit them again.
311 */
312 dev->dmat_subregion_p = true;
313 dev->dmat_subregion_min = min_addr;
314 dev->dmat_subregion_max = max_addr;
315
316 /* Success! */
317 return 0;
318}
319