1 /* $NetBSD: drm_memory.c,v 1.17 2021/12/19 10:47:13 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 1.17 2021/12/19 10:47:13 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_device.h> 75 #include <drm/drm_drv.h> 76 #include <drm/drm_cache.h> 77 #include <drm/drm_legacy.h> 78 #include <drm/drm_pci.h> 79 #include <drm/drm_print.h> 80 81 /* 82 * XXX drm_bus_borrow is a horrible kludge! 83 */ 84 static bool 85 drm_bus_borrow(bus_addr_t base, bus_size_t size, bus_space_handle_t *handlep) 86 { 87 88 #if NAGP_I810 > 0 89 if (agp_i810_borrow(base, size, handlep)) 90 return true; 91 #endif 92 93 #if NGENFB > 0 94 if (genfb_borrow(base, handlep)) 95 return true; 96 #endif 97 98 return false; 99 } 100 101 void 102 drm_legacy_ioremap(struct drm_local_map *map, struct drm_device *dev) 103 { 104 const bus_space_tag_t bst = dev->bst; 105 unsigned int unit; 106 107 /* 108 * Search dev's bus maps for a match. 109 */ 110 for (unit = 0; unit < dev->bus_nmaps; unit++) { 111 struct drm_bus_map *const bm = &dev->bus_maps[unit]; 112 int flags = bm->bm_flags; 113 114 /* Reject maps starting after the request. */ 115 if (map->offset < bm->bm_base) 116 continue; 117 118 /* Reject maps smaller than the request. */ 119 if (bm->bm_size < map->size) 120 continue; 121 122 /* Reject maps that the request doesn't fit in. */ 123 if ((bm->bm_size - map->size) < 124 (map->offset - bm->bm_base)) 125 continue; 126 127 /* Ensure we can map the space into virtual memory. */ 128 if (!ISSET(flags, BUS_SPACE_MAP_LINEAR)) 129 continue; 130 131 /* Reflect requested flags in the bus_space map. */ 132 if (ISSET(map->flags, _DRM_WRITE_COMBINING)) 133 flags |= BUS_SPACE_MAP_PREFETCHABLE; 134 135 /* Map it. */ 136 if (bus_space_map(bst, map->offset, map->size, flags, 137 &map->lm_data.bus_space.bsh)) 138 break; 139 140 map->lm_data.bus_space.bus_map = bm; 141 goto win; 142 } 143 144 /* Couldn't map it. Try borrowing from someone else. */ 145 if (drm_bus_borrow(map->offset, map->size, 146 &map->lm_data.bus_space.bsh)) { 147 map->lm_data.bus_space.bus_map = NULL; 148 goto win; 149 } 150 151 /* Failure! */ 152 return; 153 154 win: map->lm_data.bus_space.bst = bst; 155 map->handle = bus_space_vaddr(bst, map->lm_data.bus_space.bsh); 156 } 157 158 void 159 drm_legacy_ioremapfree(struct drm_local_map *map, struct drm_device *dev) 160 { 161 if (map->lm_data.bus_space.bus_map != NULL) { 162 bus_space_unmap(map->lm_data.bus_space.bst, 163 map->lm_data.bus_space.bsh, map->size); 164 map->lm_data.bus_space.bus_map = NULL; 165 map->handle = NULL; 166 } 167 } 168 169 /* 170 * Allocate a drm dma handle, allocate memory fit for DMA, and map it. 171 * 172 * XXX This is called drm_pci_alloc for hysterical raisins; it is not 173 * specific to PCI. 174 * 175 * XXX For now, we use non-blocking allocations because this is called 176 * by ioctls with the drm global mutex held. 177 * 178 * XXX Error information is lost because this returns NULL on failure, 179 * not even an error embedded in a pointer. 180 */ 181 struct drm_dma_handle * 182 drm_pci_alloc(struct drm_device *dev, size_t size, size_t align) 183 { 184 int nsegs; 185 int error; 186 187 /* 188 * Allocate a drm_dma_handle record. 189 */ 190 struct drm_dma_handle *const dmah = kmem_alloc(sizeof(*dmah), 191 KM_NOSLEEP); 192 if (dmah == NULL) { 193 error = -ENOMEM; 194 goto out; 195 } 196 dmah->dmah_tag = dev->dmat; 197 198 /* 199 * Allocate the requested amount of DMA-safe memory. 200 */ 201 /* XXX errno NetBSD->Linux */ 202 error = -bus_dmamem_alloc(dmah->dmah_tag, size, align, 0, 203 &dmah->dmah_seg, 1, &nsegs, BUS_DMA_NOWAIT); 204 if (error) 205 goto fail0; 206 KASSERT(nsegs == 1); 207 208 /* 209 * Map the DMA-safe memory into kernel virtual address space. 210 */ 211 /* XXX errno NetBSD->Linux */ 212 error = -bus_dmamem_map(dmah->dmah_tag, &dmah->dmah_seg, 1, size, 213 &dmah->vaddr, 214 (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE)); 215 if (error) 216 goto fail1; 217 dmah->size = size; 218 219 /* 220 * Create a map for DMA transfers. 221 */ 222 /* XXX errno NetBSD->Linux */ 223 error = -bus_dmamap_create(dmah->dmah_tag, size, 1, size, 0, 224 BUS_DMA_NOWAIT, &dmah->dmah_map); 225 if (error) 226 goto fail2; 227 228 /* 229 * Load the kva buffer into the map for DMA transfers. 230 */ 231 /* XXX errno NetBSD->Linux */ 232 error = -bus_dmamap_load(dmah->dmah_tag, dmah->dmah_map, dmah->vaddr, 233 size, NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE)); 234 if (error) 235 goto fail3; 236 237 /* Record the bus address for convenient reference. */ 238 dmah->busaddr = dmah->dmah_map->dm_segs[0].ds_addr; 239 240 /* Zero the DMA buffer. XXX Yikes! Is this necessary? */ 241 memset(dmah->vaddr, 0, size); 242 243 /* Success! */ 244 return dmah; 245 246 fail3: bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 247 fail2: bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 248 fail1: bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 249 fail0: dmah->dmah_tag = NULL; /* XXX paranoia */ 250 kmem_free(dmah, sizeof(*dmah)); 251 out: DRM_DEBUG("drm_pci_alloc failed: %d\n", error); 252 return NULL; 253 } 254 255 /* 256 * Release the bus DMA mappings and memory in dmah, and deallocate it. 257 */ 258 void 259 drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah) 260 { 261 262 bus_dmamap_unload(dmah->dmah_tag, dmah->dmah_map); 263 bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 264 bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 265 bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 266 dmah->dmah_tag = NULL; /* XXX paranoia */ 267 kmem_free(dmah, sizeof(*dmah)); 268 } 269 270 /* 271 * Make sure the DMA-safe memory allocated for dev lies between 272 * min_addr and max_addr. Can be used multiple times to restrict the 273 * bounds further, but never to expand the bounds again. 274 * 275 * XXX Caller must guarantee nobody has used the tag yet, 276 * i.e. allocated any DMA memory. 277 */ 278 int 279 drm_limit_dma_space(struct drm_device *dev, resource_size_t min_addr, 280 resource_size_t max_addr) 281 { 282 int ret; 283 284 KASSERT(min_addr <= max_addr); 285 286 /* 287 * Limit it further if we have already limited it, and destroy 288 * the old subregion DMA tag. 289 */ 290 if (dev->dmat_subregion_p) { 291 min_addr = MAX(min_addr, dev->dmat_subregion_min); 292 max_addr = MIN(max_addr, dev->dmat_subregion_max); 293 bus_dmatag_destroy(dev->dmat); 294 } 295 296 /* 297 * If our limit contains the 32-bit space but for some reason 298 * we can't use a subregion, either because the bus doesn't 299 * support >32-bit DMA or because bus_dma(9) on this platform 300 * lacks bus_dmatag_subregion, just use the 32-bit space. 301 */ 302 if (min_addr == 0 && max_addr >= UINT32_C(0xffffffff) && 303 dev->bus_dmat == dev->bus_dmat32) { 304 dma32: dev->dmat = dev->bus_dmat32; 305 dev->dmat_subregion_p = false; 306 dev->dmat_subregion_min = 0; 307 dev->dmat_subregion_max = UINT32_C(0xffffffff); 308 return 0; 309 } 310 311 /* 312 * Create a DMA tag for a subregion from the bus's DMA tag. If 313 * that fails, restore dev->dmat to the whole region so that we 314 * need not worry about dev->dmat being uninitialized (not that 315 * the caller should try to allocate DMA-safe memory on failure 316 * anyway, but...paranoia). 317 */ 318 /* XXX errno NetBSD->Linux */ 319 ret = -bus_dmatag_subregion(dev->bus_dmat, min_addr, max_addr, 320 &dev->dmat, BUS_DMA_WAITOK); 321 if (ret) { 322 /* 323 * bus_dmatag_subregion may fail. If so, and if the 324 * subregion contains the 32-bit space, just use the 325 * 32-bit DMA tag. 326 */ 327 if (ret == -EOPNOTSUPP && dev->bus_dmat32 && 328 min_addr == 0 && max_addr >= UINT32_C(0xffffffff)) 329 goto dma32; 330 /* XXX Back out? */ 331 dev->dmat = dev->bus_dmat; 332 dev->dmat_subregion_p = false; 333 dev->dmat_subregion_min = 0; 334 dev->dmat_subregion_max = __type_max(bus_addr_t); 335 return ret; 336 } 337 338 /* 339 * Remember that we have a subregion tag so that we know to 340 * destroy it later, and record the bounds in case we need to 341 * limit them again. 342 */ 343 dev->dmat_subregion_p = true; 344 dev->dmat_subregion_min = min_addr; 345 dev->dmat_subregion_max = max_addr; 346 347 /* Success! */ 348 return 0; 349 } 350 351 bool 352 drm_need_swiotlb(int dma_bits) 353 { 354 355 return false; 356 } 357
Indexes created Tue Sep 30 17:09:57 GMT 2025