1 /* $NetBSD: drm_memory.c,v 1.5 2014/07/01 16:29:57 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 1.5 2014/07/01 16:29:57 riastradh Exp $"); 34 35 #ifdef _KERNEL_OPT 36 #include "agp_i810.h" 37 #include "genfb.h" 38 #else 39 #define NAGP_I810 1 /* XXX WTF? */ 40 #define NGENFB 0 /* XXX WTF? */ 41 #endif 42 43 #include <sys/bus.h> 44 45 #if NAGP_I810 > 0 46 /* XXX include order botch -- shouldn't need to include pcivar.h */ 47 #include <dev/pci/pcivar.h> 48 #include <dev/pci/agpvar.h> 49 #endif 50 51 #if NGENFB > 0 52 #include <dev/wsfb/genfbvar.h> 53 #endif 54 55 #include <drm/drmP.h> 56 57 /* 58 * XXX drm_bus_borrow is a horrible kludge! 59 */ 60 static bool 61 drm_bus_borrow(bus_addr_t base, bus_size_t size, bus_space_handle_t *handlep) 62 { 63 64 #if NAGP_I810 > 0 65 if (agp_i810_borrow(base, size, handlep)) 66 return true; 67 #endif 68 69 #if NGENFB > 0 70 if (genfb_borrow(base, handlep)) 71 return true; 72 #endif 73 74 return false; 75 } 76 77 void * 78 drm_ioremap(struct drm_device *dev, struct drm_local_map *map) 79 { 80 const bus_space_tag_t bst = dev->bst; 81 unsigned int unit; 82 83 /* 84 * Search dev's bus maps for a match. 85 */ 86 for (unit = 0; unit < dev->bus_nmaps; unit++) { 87 struct drm_bus_map *const bm = &dev->bus_maps[unit]; 88 int flags = bm->bm_flags; 89 90 /* Reject maps starting after the request. */ 91 if (map->offset < bm->bm_base) 92 continue; 93 94 /* Reject maps smaller than the request. */ 95 if (bm->bm_size < map->size) 96 continue; 97 98 /* Reject maps that the request doesn't fit in. */ 99 if ((bm->bm_size - map->size) < 100 (map->offset - bm->bm_base)) 101 continue; 102 103 /* Ensure we can map the space into virtual memory. */ 104 if (!ISSET(flags, BUS_SPACE_MAP_LINEAR)) 105 continue; 106 107 /* Reflect requested flags in the bus_space map. */ 108 if (ISSET(map->flags, _DRM_WRITE_COMBINING)) 109 flags |= BUS_SPACE_MAP_PREFETCHABLE; 110 111 /* Map it. */ 112 if (bus_space_map(bst, map->offset, map->size, flags, 113 &map->lm_data.bus_space.bsh)) 114 break; 115 116 map->lm_data.bus_space.bus_map = bm; 117 goto win; 118 } 119 120 /* Couldn't map it. Try borrowing from someone else. */ 121 if (drm_bus_borrow(map->offset, map->size, 122 &map->lm_data.bus_space.bsh)) { 123 map->lm_data.bus_space.bus_map = NULL; 124 goto win; 125 } 126 127 /* Failure! */ 128 return NULL; 129 130 win: map->lm_data.bus_space.bst = bst; 131 return bus_space_vaddr(bst, map->lm_data.bus_space.bsh); 132 } 133 134 void 135 drm_iounmap(struct drm_device *dev, struct drm_local_map *map) 136 { 137 if (map->lm_data.bus_space.bus_map != NULL) { 138 bus_space_unmap(map->lm_data.bus_space.bst, 139 map->lm_data.bus_space.bsh, map->size); 140 map->lm_data.bus_space.bus_map = NULL; 141 } 142 } 143 144 /* 145 * Allocate a drm dma handle, allocate memory fit for DMA, and map it. 146 * 147 * XXX This is called drm_pci_alloc for hysterical raisins; it is not 148 * specific to PCI. 149 * 150 * XXX For now, we use non-blocking allocations because this is called 151 * by ioctls with the drm global mutex held. 152 * 153 * XXX Error information is lost because this returns NULL on failure, 154 * not even an error embedded in a pointer. 155 */ 156 struct drm_dma_handle * 157 drm_pci_alloc(struct drm_device *dev, size_t size, size_t align) 158 { 159 int nsegs; 160 int error; 161 162 /* 163 * Allocate a drm_dma_handle record. 164 */ 165 struct drm_dma_handle *const dmah = kmem_alloc(sizeof(*dmah), 166 KM_NOSLEEP); 167 if (dmah == NULL) { 168 error = -ENOMEM; 169 goto out; 170 } 171 dmah->dmah_tag = dev->dmat; 172 173 /* 174 * Allocate the requested amount of DMA-safe memory. 175 */ 176 /* XXX errno NetBSD->Linux */ 177 error = -bus_dmamem_alloc(dmah->dmah_tag, size, align, 0, 178 &dmah->dmah_seg, 1, &nsegs, BUS_DMA_NOWAIT); 179 if (error) 180 goto fail0; 181 KASSERT(nsegs == 1); 182 183 /* 184 * XXX Old drm passed BUS_DMA_NOWAIT below but BUS_DMA_WAITOK 185 * above. WTF? 186 */ 187 188 /* 189 * Map the DMA-safe memory into kernel virtual address space. 190 */ 191 /* XXX errno NetBSD->Linux */ 192 error = -bus_dmamem_map(dmah->dmah_tag, &dmah->dmah_seg, 1, size, 193 &dmah->vaddr, 194 (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE)); 195 if (error) 196 goto fail1; 197 dmah->size = size; 198 199 /* 200 * Create a map for DMA transfers. 201 */ 202 /* XXX errno NetBSD->Linux */ 203 error = -bus_dmamap_create(dmah->dmah_tag, size, 1, size, 0, 204 BUS_DMA_NOWAIT, &dmah->dmah_map); 205 if (error) 206 goto fail2; 207 208 /* 209 * Load the kva buffer into the map for DMA transfers. 210 */ 211 /* XXX errno NetBSD->Linux */ 212 error = -bus_dmamap_load(dmah->dmah_tag, dmah->dmah_map, dmah->vaddr, 213 size, NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE)); 214 if (error) 215 goto fail3; 216 217 /* Record the bus address for convenient reference. */ 218 dmah->busaddr = dmah->dmah_map->dm_segs[0].ds_addr; 219 220 /* Zero the DMA buffer. XXX Yikes! Is this necessary? */ 221 memset(dmah->vaddr, 0, size); 222 223 /* Success! */ 224 return dmah; 225 226 fail3: bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 227 fail2: bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 228 fail1: bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 229 fail0: dmah->dmah_tag = NULL; /* XXX paranoia */ 230 kmem_free(dmah, sizeof(*dmah)); 231 out: DRM_DEBUG("drm_pci_alloc failed: %d\n", error); 232 return NULL; 233 } 234 235 /* 236 * Release the bus DMA mappings and memory in dmah, and deallocate it. 237 */ 238 void 239 drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah) 240 { 241 242 bus_dmamap_unload(dmah->dmah_tag, dmah->dmah_map); 243 bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 244 bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 245 bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 246 dmah->dmah_tag = NULL; /* XXX paranoia */ 247 kmem_free(dmah, sizeof(*dmah)); 248 } 249 250 /* 251 * Make sure the DMA-safe memory allocated for dev lies between 252 * min_addr and max_addr. Can be used multiple times to restrict the 253 * bounds further, but never to expand the bounds again. 254 * 255 * XXX Caller must guarantee nobody has used the tag yet, 256 * i.e. allocated any DMA memory. 257 */ 258 int 259 drm_limit_dma_space(struct drm_device *dev, resource_size_t min_addr, 260 resource_size_t max_addr) 261 { 262 int ret; 263 264 KASSERT(min_addr <= max_addr); 265 266 /* 267 * Limit it further if we have already limited it, and destroy 268 * the old subregion DMA tag. 269 */ 270 if (dev->dmat_subregion_p) { 271 min_addr = MAX(min_addr, dev->dmat_subregion_min); 272 max_addr = MIN(max_addr, dev->dmat_subregion_max); 273 bus_dmatag_destroy(dev->dmat); 274 } 275 276 /* 277 * Create a DMA tag for a subregion from the bus's DMA tag. If 278 * that fails, restore dev->dmat to the whole region so that we 279 * need not worry about dev->dmat being uninitialized (not that 280 * the caller should try to allocate DMA-safe memory on failure 281 * anyway, but...paranoia). 282 */ 283 /* XXX errno NetBSD->Linux */ 284 ret = -bus_dmatag_subregion(dev->bus_dmat, min_addr, max_addr, 285 &dev->dmat, BUS_DMA_WAITOK); 286 if (ret) { 287 dev->dmat = dev->bus_dmat; 288 dev->dmat_subregion_p = false; 289 return ret; 290 } 291 292 /* 293 * Remember that we have a subregion tag so that we know to 294 * destroy it later, and record the bounds in case we need to 295 * limit them again. 296 */ 297 dev->dmat_subregion_p = true; 298 dev->dmat_subregion_min = min_addr; 299 dev->dmat_subregion_max = max_addr; 300 301 /* Success! */ 302 return 0; 303 } 304