[coreboot-gerrit] Change in libgfxinit[master]: gma: Fix GTT size reading for Gen8+

[Nico Huber (Code Review)]

Hello Angel Pons, Arthur Heymans,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/libgfxinit/+/35999

to review the following change.

Change subject: gma: Fix GTT size reading for Gen8+
......................................................................

gma: Fix GTT size reading for Gen8+

It seems the GTT size is not given in MiB any more but as a power
of 2 of MiB.

Change-Id: I13e40ad1d389d389c6fab6b2b42895179649f6da
Signed-off-by: Nico Huber 
---
M common/hw-gfx-gma.adb
1 file changed, 3 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/libgfxinit refs/changes/99/35999/1

diff --git a/common/hw-gfx-gma.adb b/common/hw-gfx-gma.adb
index 3221e3e..0d4cf15 100644
--- a/common/hw-gfx-gma.adb
+++ b/common/hw-gfx-gma.adb
@@ -690,8 +690,10 @@
    function Stolen_Size_Gen6 (GGC : Word16) return Stolen_Size_Range is
      (Stolen_Size_Range (Shift_Right (GGC, 3) and 16#1f#) * 32 * 2 ** 20);

+   function GGMS_Gen8 (GGC : Word16) return Natural is
+     (Natural (Shift_Right (GGC, 6) and 16#03#));
    function GTT_Size_Gen8 (GGC : Word16) return Natural is
-     (Natural (Shift_Right (GGC, 6) and 16#03#) * 2 ** 20);
+     (if GGMS_Gen8 (GGC) /= 0 then 2 ** (20 + GGMS_Gen8 (GGC)) else 0);

function GMS_Gen8 (GGC : Word16) return Stolen_Size_Range is
      (Stolen_Size_Range (Shift_Right (GGC, 8) and 16#ff#));