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_attrs(attachment->dev, 52 st->sgl, st->nents, dir, 53 DMA_ATTR_SKIP_CPU_SYNC)) { 54 ret = -ENOMEM; 55 goto err_free_sg; 56 } 57 58 return st; 59 60 err_free_sg: 61 sg_free_table(st); 62 err_free: 63 kfree(st); 64 err_unpin_pages: 65 i915_gem_object_unpin_pages(obj); 66 err: 67 return ERR_PTR(ret); 68 } 69 70 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment, 71 struct sg_table *sg, 72 enum dma_data_direction dir) 73 { 74 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf); 75 76 dma_unmap_sg_attrs(attachment->dev, 77 sg->sgl, sg->nents, dir, 78 DMA_ATTR_SKIP_CPU_SYNC); 79 sg_free_table(sg); 80 kfree(sg); 81 82 i915_gem_object_unpin_pages(obj); 83 } 84 85 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf) 86 { 87 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 88 89 return i915_gem_object_pin_map(obj, I915_MAP_WB); 90 } 91 92 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) 93 { 94 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 95 96 i915_gem_object_flush_map(obj); 97 i915_gem_object_unpin_map(obj); 98 } 99 100 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) 101 { 102 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 103 int ret; 104 105 if (obj->base.size < vma->vm_end - vma->vm_start) 106 return -EINVAL; 107 108 if (!obj->base.filp) 109 return -ENODEV; 110 111 ret = call_mmap(obj->base.filp, vma); 112 if (ret) 113 return ret; 114 115 fput(vma->vm_file); 116 vma->vm_file = get_file(obj->base.filp); 117 118 return 0; 119 } 120 121 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction) 122 { 123 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 124 bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE); 125 int err; 126 127 err = i915_gem_object_pin_pages(obj); 128 if (err) 129 return err; 130 131 err = i915_gem_object_lock_interruptible(obj); 132 if (err) 133 goto out; 134 135 err = i915_gem_object_set_to_cpu_domain(obj, write); 136 i915_gem_object_unlock(obj); 137 138 out: 139 i915_gem_object_unpin_pages(obj); 140 return err; 141 } 142 143 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction) 144 { 145 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); 146 int err; 147 148 err = i915_gem_object_pin_pages(obj); 149 if (err) 150 return err; 151 152 err = i915_gem_object_lock_interruptible(obj); 153 if (err) 154 goto out; 155 156 err = i915_gem_object_set_to_gtt_domain(obj, false); 157 i915_gem_object_unlock(obj); 158 159 out: 160 i915_gem_object_unpin_pages(obj); 161 return err; 162 } 163 164 static const struct dma_buf_ops i915_dmabuf_ops = { 165 .map_dma_buf = i915_gem_map_dma_buf, 166 .unmap_dma_buf = i915_gem_unmap_dma_buf, 167 .release = drm_gem_dmabuf_release, 168 .mmap = i915_gem_dmabuf_mmap, 169 .vmap = i915_gem_dmabuf_vmap, 170 .vunmap = i915_gem_dmabuf_vunmap, 171 .begin_cpu_access = i915_gem_begin_cpu_access, 172 .end_cpu_access = i915_gem_end_cpu_access, 173 }; 174 175 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags) 176 { 177 struct drm_i915_gem_object *obj = to_intel_bo(gem_obj); 178 DEFINE_DMA_BUF_EXPORT_INFO(exp_info); 179 180 exp_info.ops = &i915_dmabuf_ops; 181 exp_info.size = gem_obj->size; 182 exp_info.flags = flags; 183 exp_info.priv = gem_obj; 184 exp_info.resv = obj->base.resv; 185 186 if (obj->ops->dmabuf_export) { 187 int ret = obj->ops->dmabuf_export(obj); 188 if (ret) 189 return ERR_PTR(ret); 190 } 191 192 return drm_gem_dmabuf_export(gem_obj->dev, &exp_info); 193 } 194 195 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj) 196 { 197 struct sg_table *pages; 198 unsigned int sg_page_sizes; 199 200 pages = dma_buf_map_attachment(obj->base.import_attach, 201 DMA_BIDIRECTIONAL); 202 if (IS_ERR(pages)) 203 return PTR_ERR(pages); 204 205 sg_page_sizes = i915_sg_page_sizes(pages->sgl); 206 207 __i915_gem_object_set_pages(obj, pages, sg_page_sizes); 208 209 return 0; 210 } 211 212 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj, 213 struct sg_table *pages) 214 { 215 dma_buf_unmap_attachment(obj->base.import_attach, pages, 216 DMA_BIDIRECTIONAL); 217 } 218 219 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = { 220 .get_pages = i915_gem_object_get_pages_dmabuf, 221 .put_pages = i915_gem_object_put_pages_dmabuf, 222 }; 223 224 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev, 225 struct dma_buf *dma_buf) 226 { 227 static struct lock_class_key lock_class; 228 struct dma_buf_attachment *attach; 229 struct drm_i915_gem_object *obj; 230 int ret; 231 232 /* is this one of own objects? */ 233 if (dma_buf->ops == &i915_dmabuf_ops) { 234 obj = dma_buf_to_obj(dma_buf); 235 /* is it from our device? */ 236 if (obj->base.dev == dev) { 237 /* 238 * Importing dmabuf exported from out own gem increases 239 * refcount on gem itself instead of f_count of dmabuf. 240 */ 241 return &i915_gem_object_get(obj)->base; 242 } 243 } 244 245 /* need to attach */ 246 attach = dma_buf_attach(dma_buf, dev->dev); 247 if (IS_ERR(attach)) 248 return ERR_CAST(attach); 249 250 get_dma_buf(dma_buf); 251 252 obj = i915_gem_object_alloc(); 253 if (obj == NULL) { 254 ret = -ENOMEM; 255 goto fail_detach; 256 } 257 258 drm_gem_private_object_init(dev, &obj->base, dma_buf->size); 259 i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class); 260 obj->base.import_attach = attach; 261 obj->base.resv = dma_buf->resv; 262 263 /* We use GTT as shorthand for a coherent domain, one that is 264 * neither in the GPU cache nor in the CPU cache, where all 265 * writes are immediately visible in memory. (That's not strictly 266 * true, but it's close! There are internal buffers such as the 267 * write-combined buffer or a delay through the chipset for GTT 268 * writes that do require us to treat GTT as a separate cache domain.) 269 */ 270 obj->read_domains = I915_GEM_DOMAIN_GTT; 271 obj->write_domain = 0; 272 273 return &obj->base; 274 275 fail_detach: 276 dma_buf_detach(dma_buf, attach); 277 dma_buf_put(dma_buf); 278 279 return ERR_PTR(ret); 280 } 281 282 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 283 #include "selftests/mock_dmabuf.c" 284 #include "selftests/i915_gem_dmabuf.c" 285 #endif 286