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

[Das, Nirmoy]

Hi Andi,

On 4/4/2023 6:57 PM, Andi Shyti wrote:
> 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.


I wasn't sure, so I removed it :)


>   Good work here!
>
> Reviewed-by: Andi Shyti <andi.shyti at linux.intel.com>


Thanks,

Nirmoy

>
> 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);
>> +}