[patch 36/87] x86/pci: fix mmconfig detection with 32bit near 4g

Greg KH
2009-06-09T10:25:09Z

[-- Attachment #1: x86-pci-fix-mmconfig-detection-with-32bit-near-4g.patch --]
[-- Type: text/plain, Size: 2308 bytes --]

2.6.29-stable review patch. If anyone has any objections, please let us know.

------------------

From: Yinghai Lu <yinghai@kernel.org>

commit 75e613cdc7bb2ba3795b1bc3ddf19476c767ba68 upstream.

Pascal reported and bisected a commit:
| x86/PCI: don't call e820_all_mapped with -1 in the mmconfig case

which broke one system system.

ACPI: Using IOAPIC for interrupt routing
PCI: MCFG configuration 0: base f0000000 segment 0 buses 0 - 255
PCI: MCFG area at f0000000 reserved in ACPI motherboard resources
PCI: Using MMCONFIG for extended config space

it didn't have
PCI: updated MCFG configuration 0: base f0000000 segment 0 buses 0 - 63
anymore, and try to use 0xf000000 - 0xffffffff for mmconfig

For 32bit, mcfg_res->end could be 32bit only (if 64 resources aren't used)
So use end - 1 to pass the value in mcfg->end to avoid overflow.

We don't need to worry about the e820 path, they are always 64 bit.

Reported-by: Pascal Terjan <pterjan@mandriva.com>
Bisected-by: Pascal Terjan <pterjan@mandriva.com>
Tested-by: Pascal Terjan <pterjan@mandriva.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/x86/pci/mmconfig-shared.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -254,7 +254,7 @@ static acpi_status __init check_mcfg_res
if (!fixmem32)
return AE_OK;
if ((mcfg_res->start >= fixmem32->address) &&
- (mcfg_res->end <= (fixmem32->address +
+ (mcfg_res->end < (fixmem32->address +
fixmem32->address_length))) {
mcfg_res->flags = 1;
return AE_CTRL_TERMINATE;
@@ -271,7 +271,7 @@ static acpi_status __init check_mcfg_res
return AE_OK;

if ((mcfg_res->start >= address.minimum) &&
- (mcfg_res->end <= (address.minimum + address.address_length))) {
+ (mcfg_res->end < (address.minimum + address.address_length))) {
mcfg_res->flags = 1;
return AE_CTRL_TERMINATE;
}
@@ -297,7 +297,7 @@ static int __init is_acpi_reserved(u64 s
struct resource mcfg_res;

mcfg_res.start = start;
- mcfg_res.end = end;
+ mcfg_res.end = end - 1;
mcfg_res.flags = 0;

acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);