PCI/ACPI: Fix bus range comparison in pci_mcfg_lookup()
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>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 @@
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;
}