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PCI/ACPI: Fix bus range comparison in pci_mcfg_lookup()

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The configuration data provided by an MCFG entry, i.e., PCI segment and bus
range, may span multiple host bridges.

pci_mcfg_lookup() previously required an exact match of the host bridge
starting bus and the MCFG starting bus, which made the following
configuration fail:

  MCFG region:
    segment: 0
    bus range: 0x00-0xff

  host bridge
    segment: 0
    bus range: 0x20-0x4f

Relax the bus range check in pci_mcfg_lookup() so we can use any MCFG entry
that contains the required bus range, as we do in pci_mmconfig_lookup().

[bhelgaas: changelog]
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tomasz Nowicki <tn@semihalf.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
This commit is contained in:
Zhou Wang 2017-01-04 15:00:06 +08:00 committed by Bjorn Helgaas
parent 977509f7c5
commit 53762ba810
1 changed files with 2 additions and 3 deletions
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5
drivers/acpi/pci_mcfg.c
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@ -195,11 +195,10 @@ int pci_mcfg_lookup(struct acpi_pci_root *root, struct resource *cfgres,
goto skip_lookup;
/*
* We expect exact match, unless MCFG entry end bus covers more than
* specified by caller.
* We expect the range in bus_res in the coverage of MCFG bus range.
*/
list_for_each_entry(e, &pci_mcfg_list, list) {
if (e->segment == seg && e->bus_start == bus_res->start &&
if (e->segment == seg && e->bus_start <= bus_res->start &&
e->bus_end >= bus_res->end) {
root->mcfg_addr = e->addr;
}