drm_scatter.c revision 1.2.4.2
1 1.2.4.2 rmind /* $NetBSD: drm_scatter.c,v 1.2.4.2 2014/05/18 17:46:00 rmind Exp $ */ 2 1.2.4.2 rmind 3 1.2.4.2 rmind /*- 4 1.2.4.2 rmind * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 1.2.4.2 rmind * All rights reserved. 6 1.2.4.2 rmind * 7 1.2.4.2 rmind * This code is derived from software contributed to The NetBSD Foundation 8 1.2.4.2 rmind * by Taylor R. Campbell. 9 1.2.4.2 rmind * 10 1.2.4.2 rmind * Redistribution and use in source and binary forms, with or without 11 1.2.4.2 rmind * modification, are permitted provided that the following conditions 12 1.2.4.2 rmind * are met: 13 1.2.4.2 rmind * 1. Redistributions of source code must retain the above copyright 14 1.2.4.2 rmind * notice, this list of conditions and the following disclaimer. 15 1.2.4.2 rmind * 2. Redistributions in binary form must reproduce the above copyright 16 1.2.4.2 rmind * notice, this list of conditions and the following disclaimer in the 17 1.2.4.2 rmind * documentation and/or other materials provided with the distribution. 18 1.2.4.2 rmind * 19 1.2.4.2 rmind * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.2.4.2 rmind * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2.4.2 rmind * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2.4.2 rmind * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.2.4.2 rmind * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.2.4.2 rmind * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.2.4.2 rmind * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.2.4.2 rmind * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.2.4.2 rmind * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.2.4.2 rmind * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.2.4.2 rmind * POSSIBILITY OF SUCH DAMAGE. 30 1.2.4.2 rmind */ 31 1.2.4.2 rmind 32 1.2.4.2 rmind #include <sys/cdefs.h> 33 1.2.4.2 rmind __KERNEL_RCSID(0, "$NetBSD: drm_scatter.c,v 1.2.4.2 2014/05/18 17:46:00 rmind Exp $"); 34 1.2.4.2 rmind 35 1.2.4.2 rmind #include <sys/types.h> 36 1.2.4.2 rmind #include <sys/bus.h> 37 1.2.4.2 rmind #include <sys/errno.h> 38 1.2.4.2 rmind #include <sys/systm.h> 39 1.2.4.2 rmind 40 1.2.4.2 rmind #include <linux/slab.h> 41 1.2.4.2 rmind 42 1.2.4.2 rmind #include <drm/drmP.h> 43 1.2.4.2 rmind 44 1.2.4.2 rmind static int drm_sg_alloc_mem(struct drm_device *, size_t, 45 1.2.4.2 rmind struct drm_sg_mem **); 46 1.2.4.2 rmind 47 1.2.4.2 rmind int 48 1.2.4.2 rmind drm_sg_alloc_ioctl(struct drm_device *dev, void *data, 49 1.2.4.2 rmind struct drm_file *file __unused) 50 1.2.4.2 rmind { 51 1.2.4.2 rmind struct drm_scatter_gather *const request = data; 52 1.2.4.2 rmind struct drm_sg_mem *sg; 53 1.2.4.2 rmind int error; 54 1.2.4.2 rmind 55 1.2.4.2 rmind /* 56 1.2.4.2 rmind * XXX Should not hold this mutex during drm_sg_alloc. For 57 1.2.4.2 rmind * now, we'll just use non-blocking allocations. 58 1.2.4.2 rmind */ 59 1.2.4.2 rmind KASSERT(mutex_is_locked(&drm_global_mutex)); 60 1.2.4.2 rmind 61 1.2.4.2 rmind /* 62 1.2.4.2 rmind * Sanity-check the inputs. 63 1.2.4.2 rmind */ 64 1.2.4.2 rmind if (!drm_core_check_feature(dev, DRIVER_SG)) 65 1.2.4.2 rmind return -ENODEV; 66 1.2.4.2 rmind if (dev->sg != NULL) 67 1.2.4.2 rmind return -EBUSY; 68 1.2.4.2 rmind if (request->size > 0xffffffffUL) 69 1.2.4.2 rmind return -ENOMEM; 70 1.2.4.2 rmind 71 1.2.4.2 rmind /* 72 1.2.4.2 rmind * Do the allocation. 73 1.2.4.2 rmind * 74 1.2.4.2 rmind * XXX Would it be safe to drop drm_global_mutex here to avoid 75 1.2.4.2 rmind * holding it during allocation? 76 1.2.4.2 rmind */ 77 1.2.4.2 rmind error = drm_sg_alloc_mem(dev, request->size, &sg); 78 1.2.4.2 rmind if (error) 79 1.2.4.2 rmind return error; 80 1.2.4.2 rmind 81 1.2.4.2 rmind /* Set it up to be the device's scatter-gather memory. */ 82 1.2.4.2 rmind dev->sg = sg; 83 1.2.4.2 rmind 84 1.2.4.2 rmind /* Success! */ 85 1.2.4.2 rmind request->handle = sg->handle; 86 1.2.4.2 rmind return 0; 87 1.2.4.2 rmind } 88 1.2.4.2 rmind 89 1.2.4.2 rmind int 90 1.2.4.2 rmind drm_sg_free(struct drm_device *dev, void *data, struct drm_file *file) 91 1.2.4.2 rmind { 92 1.2.4.2 rmind struct drm_scatter_gather *const request = data; 93 1.2.4.2 rmind struct drm_sg_mem *sg; 94 1.2.4.2 rmind 95 1.2.4.2 rmind KASSERT(mutex_is_locked(&drm_global_mutex)); 96 1.2.4.2 rmind 97 1.2.4.2 rmind /* 98 1.2.4.2 rmind * Sanity-check the inputs. 99 1.2.4.2 rmind */ 100 1.2.4.2 rmind if (!drm_core_check_feature(dev, DRIVER_SG)) 101 1.2.4.2 rmind return -ENODEV; 102 1.2.4.2 rmind 103 1.2.4.2 rmind sg = dev->sg; 104 1.2.4.2 rmind if (sg == NULL) 105 1.2.4.2 rmind return -ENXIO; 106 1.2.4.2 rmind if (sg->handle != request->handle) 107 1.2.4.2 rmind return -EINVAL; 108 1.2.4.2 rmind 109 1.2.4.2 rmind /* Remove dev->sg. */ 110 1.2.4.2 rmind dev->sg = NULL; 111 1.2.4.2 rmind 112 1.2.4.2 rmind /* Success! */ 113 1.2.4.2 rmind drm_sg_cleanup(sg); 114 1.2.4.2 rmind return 0; 115 1.2.4.2 rmind } 116 1.2.4.2 rmind 117 1.2.4.2 rmind static int 118 1.2.4.2 rmind drm_sg_alloc_mem(struct drm_device *dev, size_t size, struct drm_sg_mem **sgp) 119 1.2.4.2 rmind { 120 1.2.4.2 rmind int nsegs; 121 1.2.4.2 rmind int error; 122 1.2.4.2 rmind 123 1.2.4.2 rmind KASSERT(drm_core_check_feature(dev, DRIVER_SG)); 124 1.2.4.2 rmind 125 1.2.4.2 rmind KASSERT(size <= (size_t)0xffffffffUL); /* XXX 32-bit sizes only? */ 126 1.2.4.2 rmind const size_t nbytes = PAGE_ALIGN(size); 127 1.2.4.2 rmind const size_t npages = nbytes >> PAGE_SHIFT; 128 1.2.4.2 rmind KASSERT(npages <= (size_t)INT_MAX); 129 1.2.4.2 rmind 130 1.2.4.2 rmind /* 131 1.2.4.2 rmind * Allocate a drm_sg_mem record. 132 1.2.4.2 rmind */ 133 1.2.4.2 rmind struct drm_sg_mem *const sg = 134 1.2.4.2 rmind kmem_zalloc(offsetof(struct drm_sg_mem, sg_segs[npages]), 135 1.2.4.2 rmind KM_NOSLEEP); 136 1.2.4.2 rmind if (sg == NULL) 137 1.2.4.2 rmind return -ENOMEM; 138 1.2.4.2 rmind sg->sg_tag = dev->dmat; 139 1.2.4.2 rmind sg->sg_nsegs_max = (unsigned int)npages; 140 1.2.4.2 rmind 141 1.2.4.2 rmind /* 142 1.2.4.2 rmind * Allocate the requested amount of DMA-safe memory. 143 1.2.4.2 rmind */ 144 1.2.4.2 rmind KASSERT(sg->sg_nsegs_max <= (unsigned int)INT_MAX); 145 1.2.4.2 rmind /* XXX errno NetBSD->Linux */ 146 1.2.4.2 rmind error = -bus_dmamem_alloc(sg->sg_tag, nbytes, PAGE_SIZE, 0, 147 1.2.4.2 rmind sg->sg_segs, (int)sg->sg_nsegs_max, &nsegs, BUS_DMA_NOWAIT); 148 1.2.4.2 rmind if (error) 149 1.2.4.2 rmind goto fail0; 150 1.2.4.2 rmind KASSERT(0 <= nsegs); 151 1.2.4.2 rmind sg->sg_nsegs = (unsigned int)nsegs; 152 1.2.4.2 rmind 153 1.2.4.2 rmind /* 154 1.2.4.2 rmind * XXX Old drm passed DRM_BUS_NOWAIT below but BUS_DMA_WAITOK 155 1.2.4.2 rmind * above. WTF? 156 1.2.4.2 rmind */ 157 1.2.4.2 rmind 158 1.2.4.2 rmind /* 159 1.2.4.2 rmind * Map the DMA-safe memory into kernel virtual address space. 160 1.2.4.2 rmind */ 161 1.2.4.2 rmind /* XXX errno NetBSD->Linux */ 162 1.2.4.2 rmind error = -bus_dmamem_map(sg->sg_tag, sg->sg_segs, nsegs, nbytes, 163 1.2.4.2 rmind &sg->virtual, 164 1.2.4.2 rmind (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE)); 165 1.2.4.2 rmind if (error) 166 1.2.4.2 rmind goto fail1; 167 1.2.4.2 rmind sg->sg_size = nbytes; 168 1.2.4.2 rmind 169 1.2.4.2 rmind /* 170 1.2.4.2 rmind * Create a map for DMA transfers. 171 1.2.4.2 rmind */ 172 1.2.4.2 rmind /* XXX errno NetBSD->Linux */ 173 1.2.4.2 rmind error = -bus_dmamap_create(sg->sg_tag, nbytes, nsegs, nbytes, 0, 174 1.2.4.2 rmind BUS_DMA_NOWAIT, &sg->sg_map); 175 1.2.4.2 rmind if (error) 176 1.2.4.2 rmind goto fail2; 177 1.2.4.2 rmind 178 1.2.4.2 rmind /* 179 1.2.4.2 rmind * Load the kva buffer into the map for DMA transfers. 180 1.2.4.2 rmind */ 181 1.2.4.2 rmind /* XXX errno NetBSD->Linux */ 182 1.2.4.2 rmind error = -bus_dmamap_load(sg->sg_tag, sg->sg_map, sg->virtual, nbytes, 183 1.2.4.2 rmind NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE)); 184 1.2.4.2 rmind if (error) 185 1.2.4.2 rmind goto fail3; 186 1.2.4.2 rmind 187 1.2.4.2 rmind /* 188 1.2.4.2 rmind * Use the kernel virtual address as the userland handle. 189 1.2.4.2 rmind * 190 1.2.4.2 rmind * XXX This leaks some information about kernel virtual 191 1.2.4.2 rmind * addresses to userland; should we use an idr instead? 192 1.2.4.2 rmind */ 193 1.2.4.2 rmind sg->handle = (unsigned long)(uintptr_t)sg->virtual; 194 1.2.4.2 rmind KASSERT(sg->virtual == (void *)(uintptr_t)sg->handle); 195 1.2.4.2 rmind 196 1.2.4.2 rmind /* Success! */ 197 1.2.4.2 rmind *sgp = sg; 198 1.2.4.2 rmind return 0; 199 1.2.4.2 rmind 200 1.2.4.2 rmind fail3: bus_dmamap_destroy(sg->sg_tag, sg->sg_map); 201 1.2.4.2 rmind fail2: bus_dmamem_unmap(sg->sg_tag, sg->virtual, sg->sg_size); 202 1.2.4.2 rmind fail1: KASSERT(sg->sg_nsegs <= (unsigned int)INT_MAX); 203 1.2.4.2 rmind bus_dmamem_free(sg->sg_tag, sg->sg_segs, (int)sg->sg_nsegs); 204 1.2.4.2 rmind fail0: sg->sg_tag = NULL; /* XXX paranoia */ 205 1.2.4.2 rmind kfree(sg); 206 1.2.4.2 rmind return error; 207 1.2.4.2 rmind } 208 1.2.4.2 rmind 209 1.2.4.2 rmind void 210 1.2.4.2 rmind drm_sg_cleanup(struct drm_sg_mem *sg) 211 1.2.4.2 rmind { 212 1.2.4.2 rmind 213 1.2.4.2 rmind bus_dmamap_unload(sg->sg_tag, sg->sg_map); 214 1.2.4.2 rmind bus_dmamap_destroy(sg->sg_tag, sg->sg_map); 215 1.2.4.2 rmind bus_dmamem_unmap(sg->sg_tag, sg->virtual, sg->sg_size); 216 1.2.4.2 rmind KASSERT(sg->sg_nsegs <= (unsigned int)INT_MAX); 217 1.2.4.2 rmind bus_dmamem_free(sg->sg_tag, sg->sg_segs, (int)sg->sg_nsegs); 218 1.2.4.2 rmind sg->sg_tag = NULL; /* XXX paranoia */ 219 1.2.4.2 rmind kmem_free(sg, offsetof(struct drm_sg_mem, sg_segs[sg->sg_nsegs_max])); 220 1.2.4.2 rmind } 221
Indexes created Fri Oct 03 17:10:05 GMT 2025