x86/pci: fix mmconfig detection with 32bit near 4g

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>
Cc: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 5fa10bb9604f..8766b0e216c5 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -375,7 +375,7 @@ static acpi_status __init check_mcfg_resource(struct acpi_resource *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;
@@ -392,7 +392,7 @@ static acpi_status __init check_mcfg_resource(struct acpi_resource *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;
         }
@@ -418,7 +418,7 @@ static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used)
         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);