[PATCH v7 15/15] drm/i915: Use ttm mmap handling for ttm bo's.

[Thomas Hellström (Intel)]

On 5/31/21 2:19 PM, Thomas Hellström wrote:
> From: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>
> Use the ttm handlers for servicing page faults, and vm_access.
>
> We do our own validation of read-only access, otherwise use the
> ttm handlers as much as possible.
>
> Because the ttm handlers expect the vma_node at vma->base, we slightly
> need to massage the mmap handlers to look at vma_node->driver_private
> to fetch the bo, if it's NULL, we assume i915's normal mmap_offset uapi
> is used.
>
> This is the easiest way to achieve compatibility without changing ttm's
> semantics.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>