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Commit a83fe32f authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

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: default avatarJack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: default avatarYinghai Lu <yhlu.kernel@gmail.com>
Cc: jbarnes@virtuousgeek.org
Cc: Jack Howarth <howarth@bromo.msbb.uc.edu>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0679c2f4

arch/x86/pci/mmconfig-shared.c

+48 −17
Original line number Diff line number Diff line
@@ -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;