VT: Allow to get max font width and height

The Console drivers has more restrictive font size limits than vt_ioctl.
This leads to errors that are difficult to handle. If a font whose size
is not supported is used, an EINVAL error will be returned, which is
also returned in case of errors in the font itself. At the moment there
is no way to understand what font sizes the current console driver
supports.

To solve this problem, we need to transfer information about the
supported font to userspace from the console driver.

Signed-off-by: Alexey Gladkov <legion@kernel.org>
4 files changed