[coreboot-gerrit] Patch set updated for coreboot: 78a63f3 lenovo/x60/i915.c: Place GTT below top of memory

[Paul Menzel (paulepanter@users.sourceforge.net)]

Paul Menzel (paulepanter at users.sourceforge.net) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/5927

-gerrit

commit 78a63f3253efa03241c541f5becc43ae245cc2d6
Author: Paul Menzel <paulepanter at users.sourceforge.net>
Date:   Thu Jun 5 22:45:35 2014 +0200

    lenovo/x60/i915.c: Place GTT below top of memory
    
    PGETBL_CTL differs between Video BIOS (-) and native graphics init (+).
    
    -          PGETBL_CTL: 0x3ffc0001
    +          PGETBL_CTL: 0x3f800001
    
    Currently it is set above the base address of stolen memory. The
    Video BIOS sets it below. The Linux Intel driver expects it to be
    below top of memory so do it this way.
    
    Using the GTT address in `setgtt` instead of `physbase`
    
    	setgtt(0, FRAME_BUFFER_PAGES, temp & 0xfffff000, 4096);
    
    causes corruptions in GRUB.
    
    There is still an error thrown but 3D works with Linux 3.12+.
    
    Change-Id: I0a5b04c2c5300f5056cb48075aa5804984bc9948
    Signed-off-by: Paul Menzel <paulepanter at users.sourceforge.net>
---
 src/mainboard/lenovo/x60/i915.c     | 16 ++++++++++++----
 src/mainboard/lenovo/x60/i915_reg.h |  2 ++
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/mainboard/lenovo/x60/i915.c b/src/mainboard/lenovo/x60/i915.c
index 6781cf8..dca41d7 100644
--- a/src/mainboard/lenovo/x60/i915.c
+++ b/src/mainboard/lenovo/x60/i915.c
@@ -139,11 +139,19 @@ int gtt_setup(unsigned int mmiobase);
 int gtt_setup(unsigned int mmiobase)
 {
 	unsigned long pgetbl_ctl;
+	unsigned long tom;
 
 	pgetbl_ctl = read32(mmiobase + PGETBL_CTL) & ~PGETBL_ENABLED;
 	pgetbl_ctl |= PGETBL_ENABLED;
 
-	pgetbl_ctl |= pci_read_config32(dev_find_slot(0, PCI_DEVFN(2,0)), BSM) & 0xfff00000;
+	/* The Video BIOS places the GTT right below top of memory.
+	 * It is not documented in the datasheet, but the Intel developers said
+	 * that it is normally placed there.
+	 *
+	 * TODO: Add option table value to make the GTT size runtime configurable.
+	 */
+	tom = pci_read_config8(dev_find_slot(0, PCI_DEVFN(0, 0)), TOLUD) << 24;
+	pgetbl_ctl |= tom - 256 * KiB;
 	pgetbl_ctl |= PGETBL_GTT_SIZE_256KB << 1; /* set GTT to 256kb */
 
 	write32(mmiobase + GFX_FLSH_CNTL, 0);
@@ -359,12 +367,12 @@ int i915lightup(unsigned int pphysbase, unsigned int piobase,
 		return 0;
 	}
 
-	/* Why does FRAME_BUFFER_PAGES = 768 cause corruptions in GRUB? */
-	setgtt(0, 800, physbase, 4096);
-
 	temp = READ32(PGETBL_CTL);
 	printk(BIOS_INFO, "GTT PGETBL_CTL register: 0x%lx\n", temp);
 
+	/* Why does FRAME_BUFFER_PAGES = 768 cause corruptions in GRUB? */
+	setgtt(0, 800, physbase, 4096);
+
 	if (temp & 1)
 		printk(BIOS_INFO, "GTT enabled.\n");
 	else
diff --git a/src/mainboard/lenovo/x60/i915_reg.h b/src/mainboard/lenovo/x60/i915_reg.h
index 382b822..a12ba55 100644
--- a/src/mainboard/lenovo/x60/i915_reg.h
+++ b/src/mainboard/lenovo/x60/i915_reg.h
@@ -27,6 +27,8 @@
 
 #define _PIPE(pipe, a, b) ((a) + (pipe)*((b)-(a)))
 
+#define TOLUD 0x9c
+
 /*
  * The Bridge device's PCI config space has information about the
  * fb aperture size and the amount of pre-reserved memory.