Re: [Intel-gfx] [PATCH 3/5] drm/i915: Add a function to mmap framebuffer obj

[Andi Shyti <andi.shyti@linux.intel.com>]

Hi Nirmoy,

[...]

> +int i915_gem_fb_mmap(struct drm_i915_gem_object *obj, struct vm_area_struct *vma)
> +{
> +	struct drm_i915_private *i915 = to_i915(obj->base.dev);
> +	struct drm_device *dev = &i915->drm;
> +	struct i915_mmap_offset *mmo = NULL;
> +	enum i915_mmap_type mmap_type;
> +	struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
> +
> +	if (drm_dev_is_unplugged(dev))
> +		return -ENODEV;
> +
> +	/* handle ttm object */
> +	if (obj->ops->mmap_ops) {
> +		/*
> +		 * ttm fault handler, ttm_bo_vm_fault_reserved() uses fake offset
> +		 * to calculate page offset so set that up.
> +		 */
> +		vma->vm_pgoff += drm_vma_node_start(&obj->base.vma_node);

you could have kept my r-b. Good work here!

Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com> 

Thanks,
Andi

> +	} else {
> +		/* handle stolen and smem objects */
> +		mmap_type = i915_ggtt_has_aperture(ggtt) ? I915_MMAP_TYPE_GTT : I915_MMAP_TYPE_WC;
> +		mmo = mmap_offset_attach(obj, mmap_type, NULL);
> +		if (!mmo)
> +			return -ENODEV;
> +	}
> +
> +	/*
> +	 * When we install vm_ops for mmap we are too late for
> +	 * the vm_ops->open() which increases the ref_count of
> +	 * this obj and then it gets decreased by the vm_ops->close().
> +	 * To balance this increase the obj ref_count here.
> +	 */
> +	obj = i915_gem_object_get(obj);
> +	return i915_gem_object_mmap(obj, mmo, vma);
> +}