Messages in this thread Patch in this message | | | From | Zhou Wang <> | Subject | [PATCH] ACPI/PCI: Fix bus range comparation in pci_mcfg_lookup | Date | Wed, 4 Jan 2017 15:00:06 +0800 |
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The configuration data provided by an MCFG region (ie PCI segment and bus range) may span multiple host bridges.
Current code in pci_mcfg_lookup() carries out an exact match of host bridge bus range start value against the MCFG region(s) bus range start value which would cause configurations like the following:
MCFG region: bus range: 0x00~0xff. segment: 0.
PCI host bridges configuration (segment numbers and bus ranges): host bridge 1: bus range: 0x00~0x1f. segment: 0. host bridge 2: bus range: 0x20~0x4f. segment: 0.
to fail, in that the bus range start value for host bridge 2 does not match the bus range start value of the respective MCFG region.
Relax the bus range check in pci_mcfg_lookup() to cater for PCI configurations with multiple host bridges sharing the same MCFG region.
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com> Reviewed-by: Tomasz Nowicki <tn@semihalf.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> --- drivers/acpi/pci_mcfg.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c index a6a4cea..2944353 100644 --- a/drivers/acpi/pci_mcfg.c +++ b/drivers/acpi/pci_mcfg.c @@ -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; } -- 1.9.1
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