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         ret = dma_map_sgtable(attachment->dev, st, dir, DMA_ATTR_SKIP_CPU_SYNC);
  52         if (ret)
  53                 goto err_free_sg;
  54
  55         return st;
  56
  57 err_free_sg:
  58         sg_free_table(st);
  59 err_free:
  60         kfree(st);
  61 err_unpin_pages:
  62         i915_gem_object_unpin_pages(obj);
  63 err:
  64         return ERR_PTR(ret);
  65 }
  66
  67 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
  68                                    struct sg_table *sg,
  69                                    enum dma_data_direction dir)
  70 {
  71         struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
  72
  73         dma_unmap_sgtable(attachment->dev, sg, dir, DMA_ATTR_SKIP_CPU_SYNC);
  74         sg_free_table(sg);
  75         kfree(sg);
  76
  77         i915_gem_object_unpin_pages(obj);
  78 }
  79
  80 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
  81 {
  82         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
  83
  84         return i915_gem_object_pin_map(obj, I915_MAP_WB);
  85 }
  86
  87 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
  88 {
  89         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
  90
  91         i915_gem_object_flush_map(obj);
  92         i915_gem_object_unpin_map(obj);
  93 }
  94
  95 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
  96 {
  97         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
  98         int ret;
  99
 100         if (obj->base.size < vma->vm_end - vma->vm_start)
 101                 return -EINVAL;
 102
 103         if (!obj->base.filp)
 104                 return -ENODEV;
 105
 106         ret = call_mmap(obj->base.filp, vma);
 107         if (ret)
 108                 return ret;
 109
 110         fput(vma->vm_file);
 111         vma->vm_file = get_file(obj->base.filp);
 112
 113         return 0;
 114 }
 115
 116 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 117 {
 118         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 119         bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
 120         int err;
 121
 122         err = i915_gem_object_pin_pages(obj);
 123         if (err)
 124                 return err;
 125
 126         err = i915_gem_object_lock_interruptible(obj);
 127         if (err)
 128                 goto out;
 129
 130         err = i915_gem_object_set_to_cpu_domain(obj, write);
 131         i915_gem_object_unlock(obj);
 132
 133 out:
 134         i915_gem_object_unpin_pages(obj);
 135         return err;
 136 }
 137
 138 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 139 {
 140         struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 141         int err;
 142
 143         err = i915_gem_object_pin_pages(obj);
 144         if (err)
 145                 return err;
 146
 147         err = i915_gem_object_lock_interruptible(obj);
 148         if (err)
 149                 goto out;
 150
 151         err = i915_gem_object_set_to_gtt_domain(obj, false);
 152         i915_gem_object_unlock(obj);
 153
 154 out:
 155         i915_gem_object_unpin_pages(obj);
 156         return err;
 157 }
 158
 159 static const struct dma_buf_ops i915_dmabuf_ops =  {
 160         .map_dma_buf = i915_gem_map_dma_buf,
 161         .unmap_dma_buf = i915_gem_unmap_dma_buf,
 162         .release = drm_gem_dmabuf_release,
 163         .mmap = i915_gem_dmabuf_mmap,
 164         .vmap = i915_gem_dmabuf_vmap,
 165         .vunmap = i915_gem_dmabuf_vunmap,
 166         .begin_cpu_access = i915_gem_begin_cpu_access,
 167         .end_cpu_access = i915_gem_end_cpu_access,
 168 };
 169
 170 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
 171 {
 172         struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
 173         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 174
 175         exp_info.ops = &i915_dmabuf_ops;
 176         exp_info.size = gem_obj->size;
 177         exp_info.flags = flags;
 178         exp_info.priv = gem_obj;
 179         exp_info.resv = obj->base.resv;
 180
 181         if (obj->ops->dmabuf_export) {
 182                 int ret = obj->ops->dmabuf_export(obj);
 183                 if (ret)
 184                         return ERR_PTR(ret);
 185         }
 186
 187         return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
 188 }
 189
 190 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 191 {
 192         struct sg_table *pages;
 193         unsigned int sg_page_sizes;
 194
 195         pages = dma_buf_map_attachment(obj->base.import_attach,
 196                                        DMA_BIDIRECTIONAL);
 197         if (IS_ERR(pages))
 198                 return PTR_ERR(pages);
 199
 200         sg_page_sizes = i915_sg_page_sizes(pages->sgl);
 201
 202         __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
 203
 204         return 0;
 205 }
 206
 207 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
 208                                              struct sg_table *pages)
 209 {
 210         dma_buf_unmap_attachment(obj->base.import_attach, pages,
 211                                  DMA_BIDIRECTIONAL);
 212 }
 213
 214 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
 215         .name = "i915_gem_object_dmabuf",
 216         .get_pages = i915_gem_object_get_pages_dmabuf,
 217         .put_pages = i915_gem_object_put_pages_dmabuf,
 218 };
 219
 220 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
 221                                              struct dma_buf *dma_buf)
 222 {
 223         static struct lock_class_key lock_class;
 224         struct dma_buf_attachment *attach;
 225         struct drm_i915_gem_object *obj;
 226         int ret;
 227
 228         /* is this one of own objects? */
 229         if (dma_buf->ops == &i915_dmabuf_ops) {
 230                 obj = dma_buf_to_obj(dma_buf);
 231                 /* is it from our device? */
 232                 if (obj->base.dev == dev) {
 233                         /*
 234                          * Importing dmabuf exported from out own gem increases
 235                          * refcount on gem itself instead of f_count of dmabuf.
 236                          */
 237                         return &i915_gem_object_get(obj)->base;
 238                 }
 239         }
 240
 241         /* need to attach */
 242         attach = dma_buf_attach(dma_buf, dev->dev);
 243         if (IS_ERR(attach))
 244                 return ERR_CAST(attach);
 245
 246         get_dma_buf(dma_buf);
 247
 248         obj = i915_gem_object_alloc();
 249         if (obj == NULL) {
 250                 ret = -ENOMEM;
 251                 goto fail_detach;
 252         }
 253
 254         drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
 255         i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class);
 256         obj->base.import_attach = attach;
 257         obj->base.resv = dma_buf->resv;
 258
 259         /* We use GTT as shorthand for a coherent domain, one that is
 260          * neither in the GPU cache nor in the CPU cache, where all
 261          * writes are immediately visible in memory. (That's not strictly
 262          * true, but it's close! There are internal buffers such as the
 263          * write-combined buffer or a delay through the chipset for GTT
 264          * writes that do require us to treat GTT as a separate cache domain.)
 265          */
 266         obj->read_domains = I915_GEM_DOMAIN_GTT;
 267         obj->write_domain = 0;
 268
 269         return &obj->base;
 270
 271 fail_detach:
 272         dma_buf_detach(dma_buf, attach);
 273         dma_buf_put(dma_buf);
 274
 275         return ERR_PTR(ret);
 276 }
 277
 278 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 279 #include "selftests/mock_dmabuf.c"
 280 #include "selftests/i915_gem_dmabuf.c"
 281 #endif