blob: fa52e2290e405d6e79d67d9551b977ce499a6c38 [file] [log] [blame]
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2012 secunet Security Networks AG
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; version 2 of
* the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc.
*/
// Use simple device model for this file even in ramstage
#define __SIMPLE_DEVICE__
#include <stdint.h>
#include <arch/io.h>
#include <device/pci_def.h>
#include <console/console.h>
#include <cbmem.h>
#include "gm45.h"
/** Decodes used Graphics Mode Select (GMS) to kilobytes. */
u32 decode_igd_memory_size(const u32 gms)
{
switch (gms) {
case 1:
return 1 << 10;
case 2:
return 4 << 10; /* guessed */
case 3:
return 8 << 10; /* guessed */
case 4:
return 16 << 10;
case 5:
return 32 << 10;
case 6:
return 48 << 10;
case 7:
return 64 << 10;
case 8:
return 128 << 10;
case 9:
return 256 << 10;
case 10:
return 96 << 10;
case 11:
return 160 << 10;
case 12:
return 224 << 10;
case 13:
return 352 << 10;
default:
die("Bad Graphics Mode Select (GMS) setting.\n");
return 0;
}
}
/** Decodes used Graphics Stolen Memory (GSM) to kilobytes. */
u32 decode_igd_gtt_size(const u32 gsm)
{
switch (gsm) {
case 0:
return 0 << 10;
case 1:
return 1 << 10;
case 3:
case 9:
return 2 << 10;
case 10:
return 3 << 10;
case 11:
return 4 << 10;
default:
die("Bad Graphics Stolen Memory (GSM) setting.\n");
return 0;
}
}
static uintptr_t smm_region_start(void)
{
const pci_devfn_t dev = PCI_DEV(0, 0, 0);
u32 tor;
/* Top of Lower Usable DRAM */
tor = (pci_read_config16(dev, D0F0_TOLUD) & 0xfff0) << 16;
/* Graphics memory comes next */
const u32 ggc = pci_read_config16(dev, D0F0_GGC);
if (!(ggc & 2)) {
/* Graphics memory */
tor -= decode_igd_memory_size((ggc >> 4) & 0xf) << 10;
/* GTT Graphics Stolen Memory Size (GGMS) */
tor -= decode_igd_gtt_size((ggc >> 8) & 0xf) << 10;
}
return tor;
}
void *cbmem_top(void)
{
return (void *) smm_region_start();
}