Patch merged into coreboot/master: cc95f18 intel/i945/gma: Place GTT below top of memory

the following patch was just integrated into master:
commit cc95f189731907dc5847cd62b398217e6f9f91f0
Author: Paul Menzel 
Date:   Thu Jun 5 22:45:35 2014 +0200

intel/i945/gma: Place GTT below top of memory

Since commit 17fec8a0 [1]

drm/i915: Use Graphics Base of Stolen Memory on all gen3+

present in the Linux kernel since version 3.12, 3D does not work
    anymore [2].

Comparing the graphics registers, in this case that means output of
    `intel_reg_dumper`, the vendor Video BIOS is setting the register
    PGTBL_CTL/PGETBL_CTL, only documented in the i965 datasheet [3], to
    `0x3ffc0001` on a system with 1 GB of RAM, while native graphics init
    sets it to `0x3f800001`.

Currently native graphis init sets the GTT right above the base
    address of stolen memory. The Video BIOS sets it below the top of
    memory.  The Linux Intel driver expects it to be below top of memory, so
    do it this way, by setting the address to TOM minus the size of the GTT,
    which is hardcoded to 256 KiB.

As `PGETBL_CTL` is zero by default, reading its value in the beginning
    is not necessary and is only confusing. Make it clear that the code
    calculates the value.

There is still a PTE error reported during boot, but 3D works
    with Linux 3.12+ and no user visible problems are shown.

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1...
    [2] https://bugs.freedesktop.org/show_bug.cgi?id=79038
    [3] https://01.org/linuxgraphics/sites/default/files/documentation/965_g35_vol_1...
        Intel ® 965 Express Chipset Family and
          Intel ® G35 Express Chipset Graphics Controller
          Programmer’s Reference Manual
        Volume 1: Graphics Core
        Revision 1.0a

Change-Id: I0a5b04c2c5300f5056cb48075aa5804984bc9948
    Signed-off-by: Paul Menzel 
    Signed-off-by: Francis Rowe 
    Reviewed-on: http://review.coreboot.org/5927
    Tested-by: build bot (Jenkins)
    Reviewed-by: Vladimir Serbinenko

See http://review.coreboot.org/5927 for details.

-gerrit