+/**
+ * drm_gem_mmap - memory map routine for GEM objects
+ * @filp: DRM file pointer
+ * @vma: VMA for the area to be mapped
+ *
+ * If a driver supports GEM object mapping, mmap calls on the DRM file
+ * descriptor will end up here.
+ *
+ * If we find the object based on the offset passed in (vma->vm_pgoff will
+ * contain the fake offset we created when the GTT map ioctl was called on
+ * the object), we set up the driver fault handler so that any accesses
+ * to the object can be trapped, to perform migration, GTT binding, surface
+ * register allocation, or performance monitoring.
+ */
+int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct drm_file *priv = filp->private_data;
+ struct drm_device *dev = priv->minor->dev;
+ struct drm_gem_mm *mm = dev->mm_private;
+ struct drm_map *map = NULL;
+ struct drm_gem_object *obj;
+ struct drm_hash_item *hash;
+ unsigned long prot;
+ int ret = 0;
+
+ mutex_lock(&dev->struct_mutex);
+
+ if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
+ mutex_unlock(&dev->struct_mutex);
+ return drm_mmap(filp, vma);
+ }
+
+ map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
+ if (!map ||
+ ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ /* Check for valid size. */
+ if (map->size < vma->vm_end - vma->vm_start) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ obj = map->handle;
+ if (!obj->dev->driver->gem_vm_ops) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND;
+ vma->vm_ops = obj->dev->driver->gem_vm_ops;
+ vma->vm_private_data = map->handle;
+ /* FIXME: use pgprot_writecombine when available */
+ prot = pgprot_val(vma->vm_page_prot);
+#ifdef CONFIG_X86
+ prot |= _PAGE_CACHE_WC;
+#endif
+ vma->vm_page_prot = __pgprot(prot);
+
+ vma->vm_file = filp; /* Needed for drm_vm_open() */
+ drm_vm_open_locked(vma);
+
+out_unlock:
+ mutex_unlock(&dev->struct_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_gem_mmap);