[patch 33/60] x86/pci: fix mmconfig detection with 32bit near 4g

[Greg KH]

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

------------------
From: Yinghai Lu <yinghai@xxxxxxxxxx>

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@xxxxxxxxxxxx>
Bisected-by: Pascal Terjan <pterjan@xxxxxxxxxxxx>
Tested-by: Pascal Terjan <pterjan@xxxxxxxxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 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
@@ -255,7 +255,7 @@ 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;
@@ -272,7 +272,7 @@ 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;
 	}
@@ -298,7 +298,7 @@ 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);


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