drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

   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 int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
  86 {
  87         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
  88         void *vaddr;
  89
  90         vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
  91         if (IS_ERR(vaddr))
  92                 return PTR_ERR(vaddr);
  93
  94         dma_buf_map_set_vaddr(map, vaddr);
  95
  96         return 0;
  97 }
  98
  99 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
 100 {
 101         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 102
 103         i915_gem_object_flush_map(obj);
 104         i915_gem_object_unpin_map(obj);
 105 }
 106
 107 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 108 {
 109         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 110         int ret;
 111
 112         if (obj->base.size < vma->vm_end - vma->vm_start)
 113                 return -EINVAL;
 114
 115         if (!obj->base.filp)
 116                 return -ENODEV;
 117
 118         ret = call_mmap(obj->base.filp, vma);
 119         if (ret)
 120                 return ret;
 121
 122         fput(vma->vm_file);
 123         vma->vm_file = get_file(obj->base.filp);
 124
 125         return 0;
 126 }
 127
 128 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 129 {
 130         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 131         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 132         int err;
 133
 134         err = i915_gem_object_pin_pages(obj);
 135         if (err)
 136                 return err;
 137
 138         err = i915_gem_object_lock_interruptible(obj, NULL);
 139         if (err)
 140                 goto out;
 141
 142         err = i915_gem_object_set_to_cpu_domain(obj, write);
 143         i915_gem_object_unlock(obj);
 144
 145 out:
 146         i915_gem_object_unpin_pages(obj);
 147         return err;
 148 }
 149
 150 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 151 {
 152         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 153         int err;
 154
 155         err = i915_gem_object_pin_pages(obj);
 156         if (err)
 157                 return err;
 158
 159         err = i915_gem_object_lock_interruptible(obj, NULL);
 160         if (err)
 161                 goto out;
 162
 163         err = i915_gem_object_set_to_gtt_domain(obj, false);
 164         i915_gem_object_unlock(obj);
 165
 166 out:
 167         i915_gem_object_unpin_pages(obj);
 168         return err;
 169 }
 170
 171 static const struct dma_buf_ops i915_dmabuf_ops =  {
 172         .map_dma_buf = i915_gem_map_dma_buf,
 173         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 174         .release = drm_gem_dmabuf_release,
 175         .mmap = i915_gem_dmabuf_mmap,
 176         .vmap = i915_gem_dmabuf_vmap,
 177         .vunmap = i915_gem_dmabuf_vunmap,
 178         .begin_cpu_access = i915_gem_begin_cpu_access,
 179         .end_cpu_access = i915_gem_end_cpu_access,
 180 };
 181
 182 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
 183 {
 184         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 185         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 186
 187         exp_info.ops = &i915_dmabuf_ops;
 188         exp_info.size = gem_obj->size;
 189         exp_info.flags = flags;
 190         exp_info.priv = gem_obj;
 191         exp_info.resv = obj->base.resv;
 192
 193         if (obj->ops->dmabuf_export) {
 194                 int ret = obj->ops->dmabuf_export(obj);
 195                 if (ret)
 196                         return ERR_PTR(ret);
 197         }
 198
 199         return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
 200 }
 201
 202 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 203 {
 204         struct sg_table *pages;
 205         unsigned int sg_page_sizes;
 206
 207         pages = dma_buf_map_attachment(obj->base.import_attach,
 208                                        DMA_BIDIRECTIONAL);
 209         if (IS_ERR(pages))
 210                 return PTR_ERR(pages);
 211
 212         sg_page_sizes = i915_sg_page_sizes(pages->sgl);
 213
 214         __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
 215
 216         return 0;
 217 }
 218
 219 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
 220                                              struct sg_table *pages)
 221 {
 222         dma_buf_unmap_attachment(obj->base.import_attach, pages,
 223                                  DMA_BIDIRECTIONAL);
 224 }
 225
 226 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 227         .name = "i915_gem_object_dmabuf",
 228         .get_pages = i915_gem_object_get_pages_dmabuf,
 229         .put_pages = i915_gem_object_put_pages_dmabuf,
 230 };
 231
 232 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 233                                              struct dma_buf *dma_buf)
 234 {
 235         static struct lock_class_key lock_class;
 236         struct dma_buf_attachment *attach;
 237         struct drm_i915_gem_object *obj;
 238         int ret;
 239
 240         /* is this one of own objects? */
 241         if (dma_buf->ops == &i915_dmabuf_ops) {
 242                 obj = dma_buf_to_obj(dma_buf);
 243                 /* is it from our device? */
 244                 if (obj->base.dev == dev) {
 245                         /*
 246                          * Importing dmabuf exported from out own gem increases
 247                          * refcount on gem itself instead of f_count of dmabuf.
 248                          */
 249                         return &i915_gem_object_get(obj)->base;
 250                 }
 251         }
 252
 253         /* need to attach */
 254         attach = dma_buf_attach(dma_buf, dev->dev);
 255         if (IS_ERR(attach))
 256                 return ERR_CAST(attach);
 257
 258         get_dma_buf(dma_buf);
 259
 260         obj = i915_gem_object_alloc();
 261         if (obj == NULL) {
 262                 ret = -ENOMEM;
 263                 goto fail_detach;
 264         }
 265
 266         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 267         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class);
 268         obj->base.import_attach = attach;
 269         obj->base.resv = dma_buf->resv;
 270
 271         /* We use GTT as shorthand for a coherent domain, one that is
 272          * neither in the GPU cache nor in the CPU cache, where all
 273          * writes are immediately visible in memory. (That's not strictly
 274          * true, but it's close! There are internal buffers such as the
 275          * write-combined buffer or a delay through the chipset for GTT
 276          * writes that do require us to treat GTT as a separate cache domain.)
 277          */
 278         obj->read_domains = I915_GEM_DOMAIN_GTT;
 279         obj->write_domain = 0;
 280
 281         return &obj->base;
 282
 283 fail_detach:
 284         dma_buf_detach(dma_buf, attach);
 285         dma_buf_put(dma_buf);
 286
 287         return ERR_PTR(ret);
 288 }
 289
 290 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 291 #include "selftests/mock_dmabuf.c"
 292 #include "selftests/i915_gem_dmabuf.c"
 293 #endif