From a83fe32fa668c0a17b3f99a1480b006f7d649924 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 18 Jul 2008 13:22:36 -0700 Subject: [PATCH] x86, pci: detect end_bus_number according to acpi/e820 reserved, v2 Jack Howarth reported that 2.6.26-rc9-git9 doesn't boot on MacBookPro2. the reason is a faulty BIOS update that reportes faulty resources. Nevertheless it's possible for Linux to be more resolent about this situation (and similar situations) and work around this bug, by cross-checking the mmconf range against the e820 table and ACPI resources. Change the mconf bus range from [0,0xff] to to [0, 0x3f] to match range [0xf0000000, 0xf4000000) in e820 tables. [ v2, yhlu.kernel@gmail.com: x86, pci: detect end_bus_number according to acpi/e820 reserved - fix ] Reported-by: Jack Howarth Signed-off-by: Yinghai Lu Cc: jbarnes@virtuousgeek.org Cc: Jack Howarth Signed-off-by: Ingo Molnar --- arch/x86/pci/mmconfig-shared.c | 65 +++++++++++++++++++++++++--------- 1 file changed, 48 insertions(+), 17 deletions(-) diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c index 23faaa890f..429c7014fe 100644 --- a/arch/x86/pci/mmconfig-shared.c +++ b/arch/x86/pci/mmconfig-shared.c @@ -293,7 +293,7 @@ static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl, return AE_OK; } -static int __init is_acpi_reserved(unsigned long start, unsigned long end) +static int __init is_acpi_reserved(u64 start, u64 end, unsigned not_used) { struct resource mcfg_res; @@ -310,6 +310,41 @@ static int __init is_acpi_reserved(unsigned long start, unsigned long end) return mcfg_res.flags; } +typedef int (*check_reserved_t)(u64 start, u64 end, unsigned type); + +static int __init is_mmconf_reserved(check_reserved_t is_reserved, + u64 addr, u64 size, int i, + typeof(pci_mmcfg_config[0]) *cfg, int with_e820) +{ + u64 old_size = size; + int valid = 0; + + while (!is_reserved(addr, addr + size - 1, E820_RESERVED)) { + size >>= 1; + if (size < (16UL<<20)) + break; + } + + if (size >= (16UL<<20) || size == old_size) { + printk(KERN_NOTICE + "PCI: MCFG area at %Lx reserved in %s\n", + addr, with_e820?"E820":"ACPI motherboard resources"); + valid = 1; + + if (old_size != size) { + /* update end_bus_number */ + cfg->end_bus_number = cfg->start_bus_number + ((size>>20) - 1); + printk(KERN_NOTICE "PCI: updated MCFG configuration %d: base %lx " + "segment %hu buses %u - %u\n", + i, (unsigned long)cfg->address, cfg->pci_segment, + (unsigned int)cfg->start_bus_number, + (unsigned int)cfg->end_bus_number); + } + } + + return valid; +} + static void __init pci_mmcfg_reject_broken(int early) { typeof(pci_mmcfg_config[0]) *cfg; @@ -324,21 +359,22 @@ static void __init pci_mmcfg_reject_broken(int early) for (i = 0; i < pci_mmcfg_config_num; i++) { int valid = 0; - u32 size = (cfg->end_bus_number + 1) << 20; + u64 addr, size; + cfg = &pci_mmcfg_config[i]; + addr = cfg->start_bus_number; + addr <<= 20; + addr += cfg->address; + size = cfg->end_bus_number + 1 - cfg->start_bus_number; + size <<= 20; printk(KERN_NOTICE "PCI: MCFG configuration %d: base %lx " "segment %hu buses %u - %u\n", i, (unsigned long)cfg->address, cfg->pci_segment, (unsigned int)cfg->start_bus_number, (unsigned int)cfg->end_bus_number); - if (!early && - is_acpi_reserved(cfg->address, cfg->address + size - 1)) { - printk(KERN_NOTICE "PCI: MCFG area at %Lx reserved " - "in ACPI motherboard resources\n", - cfg->address); - valid = 1; - } + if (!early) + valid = is_mmconf_reserved(is_acpi_reserved, addr, size, i, cfg, 0); if (valid) continue; @@ -347,16 +383,11 @@ static void __init pci_mmcfg_reject_broken(int early) printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not" " reserved in ACPI motherboard resources\n", cfg->address); + /* Don't try to do this check unless configuration type 1 is available. how about type 2 ?*/ - if (raw_pci_ops && e820_all_mapped(cfg->address, - cfg->address + size - 1, - E820_RESERVED)) { - printk(KERN_NOTICE - "PCI: MCFG area at %Lx reserved in E820\n", - cfg->address); - valid = 1; - } + if (raw_pci_ops) + valid = is_mmconf_reserved(e820_all_mapped, addr, size, i, cfg, 1); if (!valid) goto reject; -- 2.39.5