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>
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c index 5fa10bb9..8766b0e 100644 --- a/arch/x86/pci/mmconfig-shared.c +++ b/arch/x86/pci/mmconfig-shared.c
@@ -375,7 +375,7 @@ 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 @@ 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 @@ 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);