The old code allowed very strange memory types.  Now it works like
all the other video drivers: ioremap_wc is used unconditionally,
and MTRRs are set if PAT is unavailable (unless MTRR is disabled
by a module parameter).

UC, WB, and WT support is gone.  If there are MTRR conflicts that prevent
addition of a WC MTRR, adding a non-conflicting MTRR is pointless; it's
better to just turn off MTRR support entirely.

As an added bonus, any MTRR added is freed on unload.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>

fix the following 'make headers_check' warning:

  usr/include/video/uvesafb.h:5: found __[us]{8,16,32,64} type without #include <linux/types.h>

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

uvesafb is an enhanced version of vesafb.  It uses a userspace helper (v86d)
to execute calls to the x86 Video BIOS functions.  The driver is not limited
to any specific arch and whether it works on a given arch or not depends on
that arch being supported by the userspace daemon.  It has been tested on
x86_32 and x86_64.

A single BIOS call is represented by an instance of the uvesafb_ktask
structure.  This structure contains a buffer, a completion struct and a
uvesafb_task substructure, containing the values of the x86 registers, a flags
field and a field indicating the length of the buffer.  Whenever a BIOS call
is made in the driver, uvesafb_exec() builds a message using the uvesafb_task
substructure and the contents of the buffer.  This message is then assigned a
random ack number and sent to the userspace daemon using the connector
interface.

The message's sequence number is used as an index for the uvfb_tasks array,
which provides a mapping from the messages coming from userspace to the
in-kernel uvesafb_ktask structs.

The userspace daemon performs the requested operation and sends a reply in the
form of a uvesafb_task struct and, optionally, a buffer.  The seq and ack
numbers in the reply should be exactly the same as those in the request.

Each message from userspace is processed by uvesafb_cn_callback() and after
passing a few sanity checks leads to the completion of a BIOS call request.

Signed-off-by: Michal Januszewski <spock@gentoo.org>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Paulo Marques <pmarques@grupopie.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>