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| author | Arjan van de Ven <arjan@linux.intel.com> | 2006-04-07 19:49:30 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-09 11:53:51 -0700 |
| commit | 946f2ee5c7312e8acac4f3ab6629e7e2d36a3646 (patch) | |
| tree | 0821a2f3f59a089b73d33f64f59331460e20355a /arch/x86_64 | |
| parent | 952223683ec989e86328c24808fdb962c4dbeb0a (diff) | |
| download | lwn-946f2ee5c7312e8acac4f3ab6629e7e2d36a3646.tar.gz lwn-946f2ee5c7312e8acac4f3ab6629e7e2d36a3646.zip | |
[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/x86_64')
| -rw-r--r-- | arch/x86_64/pci/mmconfig.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c index e616500207e4..dfe84c322552 100644 --- a/arch/x86_64/pci/mmconfig.c +++ b/arch/x86_64/pci/mmconfig.c @@ -9,6 +9,8 @@ #include <linux/init.h> #include <linux/acpi.h> #include <linux/bitmap.h> +#include <asm/e820.h> + #include "pci.h" #define MMCONFIG_APER_SIZE (256*1024*1024) @@ -161,6 +163,14 @@ 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; + } + /* RED-PEN i386 doesn't do _nocache right now */ pci_mmcfg_virt = kmalloc(sizeof(*pci_mmcfg_virt) * pci_mmcfg_config_num, GFP_KERNEL); if (pci_mmcfg_virt == NULL) { |