drm_memory.c revision 1.14
1 /* $NetBSD: drm_memory.c,v 1.14 2021/12/19 09:52:00 riastradh 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 1.14 2021/12/19 09:52:00 riastradh 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/drm_drv.h> 75 #include <drm/drm_legacy.h> 76 #include <drm/drm_pci.h> 77 #include <drm/drmP.h> 78 79 /* 80 * XXX drm_bus_borrow is a horrible kludge! 81 */ 82 static bool 83 drm_bus_borrow(bus_addr_t base, bus_size_t size, bus_space_handle_t *handlep) 84 { 85 86 #if NAGP_I810 > 0 87 if (agp_i810_borrow(base, size, handlep)) 88 return true; 89 #endif 90 91 #if NGENFB > 0 92 if (genfb_borrow(base, handlep)) 93 return true; 94 #endif 95 96 return false; 97 } 98 99 void 100 drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev) 101 { 102 const bus_space_tag_t bst = dev->bst; 103 unsigned int unit; 104 105 /* 106 * Search dev's bus maps for a match. 107 */ 108 for (unit = 0; unit < dev->bus_nmaps; unit++) { 109 struct drm_bus_map *const bm = &dev->bus_maps[unit]; 110 int flags = bm->bm_flags; 111 112 /* Reject maps starting after the request. */ 113 if (map->offset < bm->bm_base) 114 continue; 115 116 /* Reject maps smaller than the request. */ 117 if (bm->bm_size < map->size) 118 continue; 119 120 /* Reject maps that the request doesn't fit in. */ 121 if ((bm->bm_size - map->size) < 122 (map->offset - bm->bm_base)) 123 continue; 124 125 /* Ensure we can map the space into virtual memory. */ 126 if (!ISSET(flags, BUS_SPACE_MAP_LINEAR)) 127 continue; 128 129 /* Reflect requested flags in the bus_space map. */ 130 if (ISSET(map->flags, _DRM_WRITE_COMBINING)) 131 flags |= BUS_SPACE_MAP_PREFETCHABLE; 132 133 /* Map it. */ 134 if (bus_space_map(bst, map->offset, map->size, flags, 135 &map->lm_data.bus_space.bsh)) 136 break; 137 138 map->lm_data.bus_space.bus_map = bm; 139 goto win; 140 } 141 142 /* Couldn't map it. Try borrowing from someone else. */ 143 if (drm_bus_borrow(map->offset, map->size, 144 &map->lm_data.bus_space.bsh)) { 145 map->lm_data.bus_space.bus_map = NULL; 146 goto win; 147 } 148 149 /* Failure! */ 150 return; 151 152 win: map->lm_data.bus_space.bst = bst; 153 map->handle = bus_space_vaddr(bst, map->lm_data.bus_space.bsh); 154 } 155 156 void 157 drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev) 158 { 159 if (map->lm_data.bus_space.bus_map != NULL) { 160 bus_space_unmap(map->lm_data.bus_space.bst, 161 map->lm_data.bus_space.bsh, map->size); 162 map->lm_data.bus_space.bus_map = NULL; 163 map->handle = NULL; 164 } 165 } 166 167 /* 168 * Allocate a drm dma handle, allocate memory fit for DMA, and map it. 169 * 170 * XXX This is called drm_pci_alloc for hysterical raisins; it is not 171 * specific to PCI. 172 * 173 * XXX For now, we use non-blocking allocations because this is called 174 * by ioctls with the drm global mutex held. 175 * 176 * XXX Error information is lost because this returns NULL on failure, 177 * not even an error embedded in a pointer. 178 */ 179 struct drm_dma_handle * 180 drm_pci_alloc(struct drm_device *dev, size_t size, size_t align) 181 { 182 int nsegs; 183 int error; 184 185 /* 186 * Allocate a drm_dma_handle record. 187 */ 188 struct drm_dma_handle *const dmah = kmem_alloc(sizeof(*dmah), 189 KM_NOSLEEP); 190 if (dmah == NULL) { 191 error = -ENOMEM; 192 goto out; 193 } 194 dmah->dmah_tag = dev->dmat; 195 196 /* 197 * Allocate the requested amount of DMA-safe memory. 198 */ 199 /* XXX errno NetBSD->Linux */ 200 error = -bus_dmamem_alloc(dmah->dmah_tag, size, align, 0, 201 &dmah->dmah_seg, 1, &nsegs, BUS_DMA_NOWAIT); 202 if (error) 203 goto fail0; 204 KASSERT(nsegs == 1); 205 206 /* 207 * Map the DMA-safe memory into kernel virtual address space. 208 */ 209 /* XXX errno NetBSD->Linux */ 210 error = -bus_dmamem_map(dmah->dmah_tag, &dmah->dmah_seg, 1, size, 211 &dmah->vaddr, 212 (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE)); 213 if (error) 214 goto fail1; 215 dmah->size = size; 216 217 /* 218 * Create a map for DMA transfers. 219 */ 220 /* XXX errno NetBSD->Linux */ 221 error = -bus_dmamap_create(dmah->dmah_tag, size, 1, size, 0, 222 BUS_DMA_NOWAIT, &dmah->dmah_map); 223 if (error) 224 goto fail2; 225 226 /* 227 * Load the kva buffer into the map for DMA transfers. 228 */ 229 /* XXX errno NetBSD->Linux */ 230 error = -bus_dmamap_load(dmah->dmah_tag, dmah->dmah_map, dmah->vaddr, 231 size, NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE)); 232 if (error) 233 goto fail3; 234 235 /* Record the bus address for convenient reference. */ 236 dmah->busaddr = dmah->dmah_map->dm_segs[0].ds_addr; 237 238 /* Zero the DMA buffer. XXX Yikes! Is this necessary? */ 239 memset(dmah->vaddr, 0, size); 240 241 /* Success! */ 242 return dmah; 243 244 fail3: bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 245 fail2: bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 246 fail1: bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 247 fail0: dmah->dmah_tag = NULL; /* XXX paranoia */ 248 kmem_free(dmah, sizeof(*dmah)); 249 out: DRM_DEBUG("drm_pci_alloc failed: %d\n", error); 250 return NULL; 251 } 252 253 /* 254 * Release the bus DMA mappings and memory in dmah, and deallocate it. 255 */ 256 void 257 drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah) 258 { 259 260 bus_dmamap_unload(dmah->dmah_tag, dmah->dmah_map); 261 bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 262 bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 263 bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 264 dmah->dmah_tag = NULL; /* XXX paranoia */ 265 kmem_free(dmah, sizeof(*dmah)); 266 } 267 268 /* 269 * Make sure the DMA-safe memory allocated for dev lies between 270 * min_addr and max_addr. Can be used multiple times to restrict the 271 * bounds further, but never to expand the bounds again. 272 * 273 * XXX Caller must guarantee nobody has used the tag yet, 274 * i.e. allocated any DMA memory. 275 */ 276 int 277 drm_limit_dma_space(struct drm_device *dev, resource_size_t min_addr, 278 resource_size_t max_addr) 279 { 280 int ret; 281 282 KASSERT(min_addr <= max_addr); 283 284 /* 285 * Limit it further if we have already limited it, and destroy 286 * the old subregion DMA tag. 287 */ 288 if (dev->dmat_subregion_p) { 289 min_addr = MAX(min_addr, dev->dmat_subregion_min); 290 max_addr = MIN(max_addr, dev->dmat_subregion_max); 291 bus_dmatag_destroy(dev->dmat); 292 } 293 294 /* 295 * If our limit contains the 32-bit space but for some reason 296 * we can't use a subregion, either because the bus doesn't 297 * support >32-bit DMA or because bus_dma(9) on this platform 298 * lacks bus_dmatag_subregion, just use the 32-bit space. 299 */ 300 if (min_addr == 0 && max_addr >= UINT32_C(0xffffffff) && 301 dev->bus_dmat == dev->bus_dmat32) { 302 dma32: dev->dmat = dev->bus_dmat32; 303 dev->dmat_subregion_p = false; 304 dev->dmat_subregion_min = 0; 305 dev->dmat_subregion_max = UINT32_C(0xffffffff); 306 return 0; 307 } 308 309 /* 310 * Create a DMA tag for a subregion from the bus's DMA tag. If 311 * that fails, restore dev->dmat to the whole region so that we 312 * need not worry about dev->dmat being uninitialized (not that 313 * the caller should try to allocate DMA-safe memory on failure 314 * anyway, but...paranoia). 315 */ 316 /* XXX errno NetBSD->Linux */ 317 ret = -bus_dmatag_subregion(dev->bus_dmat, min_addr, max_addr, 318 &dev->dmat, BUS_DMA_WAITOK); 319 if (ret) { 320 /* 321 * bus_dmatag_subregion may fail. If so, and if the 322 * subregion contains the 32-bit space, just use the 323 * 32-bit DMA tag. 324 */ 325 if (ret == -EOPNOTSUPP && dev->bus_dmat32 && 326 min_addr == 0 && max_addr >= UINT32_C(0xffffffff)) 327 goto dma32; 328 /* XXX Back out? */ 329 dev->dmat = dev->bus_dmat; 330 dev->dmat_subregion_p = false; 331 dev->dmat_subregion_min = 0; 332 dev->dmat_subregion_max = __type_max(bus_addr_t); 333 return ret; 334 } 335 336 /* 337 * Remember that we have a subregion tag so that we know to 338 * destroy it later, and record the bounds in case we need to 339 * limit them again. 340 */ 341 dev->dmat_subregion_p = true; 342 dev->dmat_subregion_min = min_addr; 343 dev->dmat_subregion_max = max_addr; 344 345 /* Success! */ 346 return 0; 347 } 348
Indexes created Tue Sep 30 20:09:53 GMT 2025