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authorArjan van de Ven <arjan@linux.intel.com>2006-04-07 19:49:30 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-09 11:53:51 -0700
commit946f2ee5c7312e8acac4f3ab6629e7e2d36a3646 (patch)
tree0821a2f3f59a089b73d33f64f59331460e20355a /arch/i386/pci
parent952223683ec989e86328c24808fdb962c4dbeb0a (diff)
[PATCH] i386/x86-64: Check that MCFG points to an e820 reserved area
This patch introduces a user for the e820_all_mapped function: There have been several machines that don't have a working MMCONFIG, often because of a buggy MCFG table in the ACPI bios. This patch adds a simple sanity check that detects a whole bunch of these cases, and when it detects it, linux now boots rather than crash-and-burns. The accuracy of this detection can in principle be improved if there was a "is this entire range in e820 with THIS attribute", but no such function exist and the complexity needed for this is not really worth it; this simple check already catches most cases anyway. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386/pci')
-rw-r--r--arch/i386/pci/mmconfig.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/i386/pci/mmconfig.c b/arch/i386/pci/mmconfig.c
index 613789071f3..ee815c7d3e4 100644
--- a/arch/i386/pci/mmconfig.c
+++ b/arch/i386/pci/mmconfig.c
@@ -12,8 +12,11 @@
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/acpi.h>
+#include <asm/e820.h>
#include "pci.h"
+#define MMCONFIG_APER_SIZE (256*1024*1024)
+
#define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
/* The base address of the last MMCONFIG device accessed */
@@ -183,6 +186,14 @@ void __init pci_mmcfg_init(void)
(pci_mmcfg_config[0].base_address == 0))
return;
+ if (!e820_all_mapped(pci_mmcfg_config[0].base_address,
+ pci_mmcfg_config[0].base_address + MMCONFIG_APER_SIZE,
+ E820_RESERVED)) {
+ printk(KERN_ERR "PCI: BIOS Bug: MCFG area is not E820-reserved\n");
+ printk(KERN_ERR "PCI: Not using MMCONFIG.\n");
+ return;
+ }
+
printk(KERN_INFO "PCI: Using MMCONFIG\n");
raw_pci_ops = &pci_mmcfg;
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;