1 /* $NetBSD: drm_memory.c,v 1.6 2014/07/16 20:56:25 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 1.6 2014/07/16 20:56:25 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 * Map the DMA-safe memory into kernel virtual address space. 185 */ 186 /* XXX errno NetBSD->Linux */ 187 error = -bus_dmamem_map(dmah->dmah_tag, &dmah->dmah_seg, 1, size, 188 &dmah->vaddr, 189 (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE)); 190 if (error) 191 goto fail1; 192 dmah->size = size; 193 194 /* 195 * Create a map for DMA transfers. 196 */ 197 /* XXX errno NetBSD->Linux */ 198 error = -bus_dmamap_create(dmah->dmah_tag, size, 1, size, 0, 199 BUS_DMA_NOWAIT, &dmah->dmah_map); 200 if (error) 201 goto fail2; 202 203 /* 204 * Load the kva buffer into the map for DMA transfers. 205 */ 206 /* XXX errno NetBSD->Linux */ 207 error = -bus_dmamap_load(dmah->dmah_tag, dmah->dmah_map, dmah->vaddr, 208 size, NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE)); 209 if (error) 210 goto fail3; 211 212 /* Record the bus address for convenient reference. */ 213 dmah->busaddr = dmah->dmah_map->dm_segs[0].ds_addr; 214 215 /* Zero the DMA buffer. XXX Yikes! Is this necessary? */ 216 memset(dmah->vaddr, 0, size); 217 218 /* Success! */ 219 return dmah; 220 221 fail3: bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 222 fail2: bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 223 fail1: bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 224 fail0: dmah->dmah_tag = NULL; /* XXX paranoia */ 225 kmem_free(dmah, sizeof(*dmah)); 226 out: DRM_DEBUG("drm_pci_alloc failed: %d\n", error); 227 return NULL; 228 } 229 230 /* 231 * Release the bus DMA mappings and memory in dmah, and deallocate it. 232 */ 233 void 234 drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah) 235 { 236 237 bus_dmamap_unload(dmah->dmah_tag, dmah->dmah_map); 238 bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map); 239 bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size); 240 bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1); 241 dmah->dmah_tag = NULL; /* XXX paranoia */ 242 kmem_free(dmah, sizeof(*dmah)); 243 } 244 245 /* 246 * Make sure the DMA-safe memory allocated for dev lies between 247 * min_addr and max_addr. Can be used multiple times to restrict the 248 * bounds further, but never to expand the bounds again. 249 * 250 * XXX Caller must guarantee nobody has used the tag yet, 251 * i.e. allocated any DMA memory. 252 */ 253 int 254 drm_limit_dma_space(struct drm_device *dev, resource_size_t min_addr, 255 resource_size_t max_addr) 256 { 257 int ret; 258 259 KASSERT(min_addr <= max_addr); 260 261 /* 262 * Limit it further if we have already limited it, and destroy 263 * the old subregion DMA tag. 264 */ 265 if (dev->dmat_subregion_p) { 266 min_addr = MAX(min_addr, dev->dmat_subregion_min); 267 max_addr = MIN(max_addr, dev->dmat_subregion_max); 268 bus_dmatag_destroy(dev->dmat); 269 } 270 271 /* 272 * Create a DMA tag for a subregion from the bus's DMA tag. If 273 * that fails, restore dev->dmat to the whole region so that we 274 * need not worry about dev->dmat being uninitialized (not that 275 * the caller should try to allocate DMA-safe memory on failure 276 * anyway, but...paranoia). 277 */ 278 /* XXX errno NetBSD->Linux */ 279 ret = -bus_dmatag_subregion(dev->bus_dmat, min_addr, max_addr, 280 &dev->dmat, BUS_DMA_WAITOK); 281 if (ret) { 282 dev->dmat = dev->bus_dmat; 283 dev->dmat_subregion_p = false; 284 return ret; 285 } 286 287 /* 288 * Remember that we have a subregion tag so that we know to 289 * destroy it later, and record the bounds in case we need to 290 * limit them again. 291 */ 292 dev->dmat_subregion_p = true; 293 dev->dmat_subregion_min = min_addr; 294 dev->dmat_subregion_max = max_addr; 295 296 /* Success! */ 297 return 0; 298 } 299