Add a mmap callback on the control device node for mapping the usermode
register region to userspace. Each such mapping is removed when the GPU
railgates, and brought back again on unrailgate.
The mapping offset must be 0 and its size must be 4 KB.
Bug 200145225
Change-Id: Ie8d3758da745b958376292691d7d1d02a24e7815
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1795819
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>