1 /* 2 * SPDX-License-Identifier: MIT 3 * 4 * Copyright 2012 Red Hat Inc 5 */ 6 7 #include <linux/dma-buf.h> 8 #include <linux/highmem.h> 9 #include <linux/dma-resv.h> 10 11 #include "i915_drv.h" 12 #include "i915_gem_object.h" 13 #include "i915_scatterlist.h" 14 15 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf) 16 { 17 return to_intel_bo(buf->priv); 18 } 19 20 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment, 21 enum dma_data_direction dir) 22 { 23 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf); 24 struct sg_table *st; 25 struct scatterlist *src, *dst; 26 int ret, i; 27 28 ret = i915_gem_object_pin_pages(obj); 29 if (ret) 30 goto err; 31 32 /* Copy sg so that we make an independent mapping */ 33 st = kmalloc(sizeof(struct sg_table), GFP_KERNEL); 34 if (st == NULL) { 35 ret = -ENOMEM; 36 goto err_unpin_pages; 37 } 38 39 ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL); 40 if (ret) 41 goto err_free; 42 43 src = obj->mm.pages->sgl; 44 dst = st->sgl; 45 for (i = 0; i < obj->mm.pages->nents; i++) { 46 sg_set_page(dst, sg_page(src), src->length, 0); 47 dst = sg_next(dst); 48 src = sg_next(src); 49 } 50 51 if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) { 52 ret = -ENOMEM; 53 goto err_free_sg; 54 } 55 56 return st; 57 58 err_free_sg: 59 sg_free_table(st); 60 err_free: 61 kfree(st); 62 err_unpin_pages: 63 i915_gem_object_unpin_pages(obj); 64 err: 65 return ERR_PTR(ret); 66 } 67 68 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, 69 struct sg_table *sg, 70 enum dma_data_direction dir) 71 { 72 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf); 73 74 dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir); 75 sg_free_table(sg); 76 kfree(sg); 77 78 i915_gem_object_unpin_pages(obj); 79 } 80 81 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf) 82 { 83 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 84 85 return i915_gem_object_pin_map(obj, I915_MAP_WB); 86 } 87 88 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) 89 { 90 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 91 92 i915_gem_object_flush_map(obj); 93 i915_gem_object_unpin_map(obj); 94 } 95 96 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num) 97 { 98 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 99 struct page *page; 100 101 if (page_num >= obj->base.size >> PAGE_SHIFT) 102 return NULL; 103 104 if (!i915_gem_object_has_struct_page(obj)) 105 return NULL; 106 107 if (i915_gem_object_pin_pages(obj)) 108 return NULL; 109 110 /* Synchronisation is left to the caller (via .begin_cpu_access()) */ 111 page = i915_gem_object_get_page(obj, page_num); 112 if (IS_ERR(page)) 113 goto err_unpin; 114 115 return kmap(page); 116 117 err_unpin: 118 i915_gem_object_unpin_pages(obj); 119 return NULL; 120 } 121 122 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr) 123 { 124 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 125 126 kunmap(virt_to_page(addr)); 127 i915_gem_object_unpin_pages(obj); 128 } 129 130 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) 131 { 132 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 133 int ret; 134 135 if (obj->base.size < vma->vm_end - vma->vm_start) 136 return -EINVAL; 137 138 if (!obj->base.filp) 139 return -ENODEV; 140 141 ret = call_mmap(obj->base.filp, vma); 142 if (ret) 143 return ret; 144 145 fput(vma->vm_file); 146 vma->vm_file = get_file(obj->base.filp); 147 148 return 0; 149 } 150 151 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction) 152 { 153 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 154 bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE); 155 int err; 156 157 err = i915_gem_object_pin_pages(obj); 158 if (err) 159 return err; 160 161 err = i915_gem_object_lock_interruptible(obj); 162 if (err) 163 goto out; 164 165 err = i915_gem_object_set_to_cpu_domain(obj, write); 166 i915_gem_object_unlock(obj); 167 168 out: 169 i915_gem_object_unpin_pages(obj); 170 return err; 171 } 172 173 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction) 174 { 175 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 176 int err; 177 178 err = i915_gem_object_pin_pages(obj); 179 if (err) 180 return err; 181 182 err = i915_gem_object_lock_interruptible(obj); 183 if (err) 184 goto out; 185 186 err = i915_gem_object_set_to_gtt_domain(obj, false); 187 i915_gem_object_unlock(obj); 188 189 out: 190 i915_gem_object_unpin_pages(obj); 191 return err; 192 } 193 194 static const struct dma_buf_ops i915_dmabuf_ops = { 195 .map_dma_buf = i915_gem_map_dma_buf, 196 .unmap_dma_buf = i915_gem_unmap_dma_buf, 197 .release = drm_gem_dmabuf_release, 198 .map = i915_gem_dmabuf_kmap, 199 .unmap = i915_gem_dmabuf_kunmap, 200 .mmap = i915_gem_dmabuf_mmap, 201 .vmap = i915_gem_dmabuf_vmap, 202 .vunmap = i915_gem_dmabuf_vunmap, 203 .begin_cpu_access = i915_gem_begin_cpu_access, 204 .end_cpu_access = i915_gem_end_cpu_access, 205 }; 206 207 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags) 208 { 209 struct drm_i915_gem_object *obj = to_intel_bo(gem_obj); 210 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 211 212 exp_info.ops = &i915_dmabuf_ops; 213 exp_info.size = gem_obj->size; 214 exp_info.flags = flags; 215 exp_info.priv = gem_obj; 216 exp_info.resv = obj->base.resv; 217 218 if (obj->ops->dmabuf_export) { 219 int ret = obj->ops->dmabuf_export(obj); 220 if (ret) 221 return ERR_PTR(ret); 222 } 223 224 return drm_gem_dmabuf_export(gem_obj->dev, &exp_info); 225 } 226 227 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj) 228 { 229 struct sg_table *pages; 230 unsigned int sg_page_sizes; 231 232 pages = dma_buf_map_attachment(obj->base.import_attach, 233 DMA_BIDIRECTIONAL); 234 if (IS_ERR(pages)) 235 return PTR_ERR(pages); 236 237 sg_page_sizes = i915_sg_page_sizes(pages->sgl); 238 239 __i915_gem_object_set_pages(obj, pages, sg_page_sizes); 240 241 return 0; 242 } 243 244 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj, 245 struct sg_table *pages) 246 { 247 dma_buf_unmap_attachment(obj->base.import_attach, pages, 248 DMA_BIDIRECTIONAL); 249 } 250 251 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = { 252 .get_pages = i915_gem_object_get_pages_dmabuf, 253 .put_pages = i915_gem_object_put_pages_dmabuf, 254 }; 255 256 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev, 257 struct dma_buf *dma_buf) 258 { 259 struct dma_buf_attachment *attach; 260 struct drm_i915_gem_object *obj; 261 int ret; 262 263 /* is this one of own objects? */ 264 if (dma_buf->ops == &i915_dmabuf_ops) { 265 obj = dma_buf_to_obj(dma_buf); 266 /* is it from our device? */ 267 if (obj->base.dev == dev) { 268 /* 269 * Importing dmabuf exported from out own gem increases 270 * refcount on gem itself instead of f_count of dmabuf. 271 */ 272 return &i915_gem_object_get(obj)->base; 273 } 274 } 275 276 /* need to attach */ 277 attach = dma_buf_attach(dma_buf, dev->dev); 278 if (IS_ERR(attach)) 279 return ERR_CAST(attach); 280 281 get_dma_buf(dma_buf); 282 283 obj = i915_gem_object_alloc(); 284 if (obj == NULL) { 285 ret = -ENOMEM; 286 goto fail_detach; 287 } 288 289 drm_gem_private_object_init(dev, &obj->base, dma_buf->size); 290 i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops); 291 obj->base.import_attach = attach; 292 obj->base.resv = dma_buf->resv; 293 294 /* We use GTT as shorthand for a coherent domain, one that is 295 * neither in the GPU cache nor in the CPU cache, where all 296 * writes are immediately visible in memory. (That's not strictly 297 * true, but it's close! There are internal buffers such as the 298 * write-combined buffer or a delay through the chipset for GTT 299 * writes that do require us to treat GTT as a separate cache domain.) 300 */ 301 obj->read_domains = I915_GEM_DOMAIN_GTT; 302 obj->write_domain = 0; 303 304 return &obj->base; 305 306 fail_detach: 307 dma_buf_detach(dma_buf, attach); 308 dma_buf_put(dma_buf); 309 310 return ERR_PTR(ret); 311 } 312 313 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 314 #include "selftests/mock_dmabuf.c" 315 #include "selftests/i915_gem_dmabuf.c" 316 #endif 317