static struct drm_i915_gem_object *
_i915_gem_object_create_stolen(struct drm_i915_private *dev_priv,
struct drm_mm_node *stolen)
{
struct drm_i915_gem_object *obj;
unsigned int cache_level;
obj = i915_gem_object_alloc(dev_priv);
if (obj == NULL)
return NULL;
drm_gem_private_object_init(&dev_priv->drm, &obj->base, stolen->size);
i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
obj->stolen = stolen;
obj->read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
cache_level = HAS_LLC(dev_priv) ? I915_CACHE_LLC : I915_CACHE_NONE;
i915_gem_object_set_cache_coherency(obj, cache_level);
if (i915_gem_object_pin_pages(obj))
goto cleanup;
return obj;
cleanup:
i915_gem_object_free(obj);
return NULL;
}
/**
* i915_gem_object_create_internal: create an object with volatile pages
* @i915: the i915 device
* @size: the size in bytes of backing storage to allocate for the object
*
* Creates a new object that wraps some internal memory for private use.
* This object is not backed by swappable storage, and as such its contents
* are volatile and only valid whilst pinned. If the object is reaped by the
* shrinker, its pages and data will be discarded. Equally, it is not a full
* GEM object and so not valid for access from userspace. This makes it useful
* for hardware interfaces like ringbuffers (which are pinned from the time
* the request is written to the time the hardware stops accessing it), but
* not for contexts (which need to be preserved when not active for later
* reuse). Note that it is not cleared upon allocation.
*/
struct drm_i915_gem_object *
i915_gem_object_create_internal(struct drm_i915_private *i915,
phys_addr_t size)
{
struct drm_i915_gem_object *obj;
unsigned int cache_level;
GEM_BUG_ON(!size);
GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));
if (overflows_type(size, obj->base.size))
return ERR_PTR(-E2BIG);
obj = i915_gem_object_alloc();
if (!obj)
return ERR_PTR(-ENOMEM);
drm_gem_private_object_init(&i915->drm, &obj->base, size);
i915_gem_object_init(obj, &i915_gem_object_internal_ops);
obj->read_domains = I915_GEM_DOMAIN_CPU;
obj->write_domain = I915_GEM_DOMAIN_CPU;
cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
i915_gem_object_set_cache_coherency(obj, cache_level);
return obj;
}
/*
* Creates a new mm object that wraps some normal memory from the process
* context - user memory.
*
* We impose several restrictions upon the memory being mapped
* into the GPU.
* 1. It must be page aligned (both start/end addresses, i.e ptr and size).
* 2. It must be normal system memory, not a pointer into another map of IO
* space (e.g. it must not be a GTT mmapping of another object).
* 3. We only allow a bo as large as we could in theory map into the GTT,
* that is we limit the size to the total size of the GTT.
* 4. The bo is marked as being snoopable. The backing pages are left
* accessible directly by the CPU, but reads and writes by the GPU may
* incur the cost of a snoop (unless you have an LLC architecture).
*
* Synchronisation between multiple users and the GPU is left to userspace
* through the normal set-domain-ioctl. The kernel will enforce that the
* GPU relinquishes the VMA before it is returned back to the system
* i.e. upon free(), munmap() or process termination. However, the userspace
* malloc() library may not immediately relinquish the VMA after free() and
* instead reuse it whilst the GPU is still reading and writing to the VMA.
* Caveat emptor.
*
* Also note, that the object created here is not currently a "first class"
* object, in that several ioctls are banned. These are the CPU access
* ioctls: mmap(), pwrite and pread. In practice, you are expected to use
* direct access via your pointer rather than use those ioctls. Another
* restriction is that we do not allow userptr surfaces to be pinned to the
* hardware and so we reject any attempt to create a framebuffer out of a
* userptr.
*
* If you think this is a good interface to use to pass GPU memory between
* drivers, please use dma-buf instead. In fact, wherever possible use
* dma-buf instead.
*/
int
i915_gem_userptr_ioctl(struct drm_device *dev,
void *data,
struct drm_file *file)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct drm_i915_gem_userptr *args = data;
struct drm_i915_gem_object *obj;
int ret;
u32 handle;
if (!HAS_LLC(dev_priv) && !HAS_SNOOP(dev_priv)) {
/* We cannot support coherent userptr objects on hw without
* LLC and broken snooping.
*/
return -ENODEV;
}
if (args->flags & ~(I915_USERPTR_READ_ONLY |
I915_USERPTR_UNSYNCHRONIZED))
return -EINVAL;
if (!args->user_size)
return -EINVAL;
if (offset_in_page(args->user_ptr | args->user_size))
return -EINVAL;
if (!access_ok((char __user *)(unsigned long)args->user_ptr, args->user_size))
return -EFAULT;
if (args->flags & I915_USERPTR_READ_ONLY) {
struct i915_hw_ppgtt *ppgtt;
/*
* On almost all of the older hw, we cannot tell the GPU that
* a page is readonly.
*/
ppgtt = dev_priv->kernel_context->ppgtt;
if (!ppgtt || !ppgtt->vm.has_read_only)
return -ENODEV;
}
obj = i915_gem_object_alloc();
if (obj == NULL)
return -ENOMEM;
drm_gem_private_object_init(dev, &obj->base, args->user_size);
i915_gem_object_init(obj, &i915_gem_userptr_ops);
obj->read_domains = I915_GEM_DOMAIN_CPU;
obj->write_domain = I915_GEM_DOMAIN_CPU;
i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);
obj->userptr.ptr = args->user_ptr;
if (args->flags & I915_USERPTR_READ_ONLY)
i915_gem_object_set_readonly(obj);
/* And keep a pointer to the current->mm for resolving the user pages
* at binding. This means that we need to hook into the mmu_notifier
* in order to detect if the mmu is destroyed.
*/
ret = i915_gem_userptr_init__mm_struct(obj);
if (ret == 0)
ret = i915_gem_userptr_init__mmu_notifier(obj, args->flags);
if (ret == 0)
ret = drm_gem_handle_create(file, &obj->base, &handle);
/* drop reference from allocate - handle holds it now */
i915_gem_object_put(obj);
if (ret)
return ret;
args->handle = handle;
return 0;
}
