On Mon, Jan 9, 2017 at 4:39 AM, Zhou Wang <[email protected]> wrote: > On 2017/1/4 15:00, Zhou Wang wrote: >> 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 <[email protected]> >> Reviewed-by: Tomasz Nowicki <[email protected]> >> Acked-by: Lorenzo Pieralisi <[email protected]> >> --- >> 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; >> } >> > > Hi Rafael, > > Could you please look into this patch if you have time?
Well, it makes sense to me, but this is PCI, so Bjorn has to decide here. Thanks, Rafael
