On 2017/1/3 20:00, Lorenzo Pieralisi wrote: > On Thu, Dec 22, 2016 at 05:07:43PM +0800, Zhou Wang wrote: >> Multiple PCIe host bridges may exists in one PCIe segment. So bus range for >> each >> host bridge should be in the coverage of bus range of related PCIe segment. >> >> This patch will support this kind of scenario: >> >> MCFG: >> bus range: 0x00~0xff. >> segment: 0. >> DSDT: >> host bridge 1: >> bus range: 0x00~0x1f. >> segment: 0. >> host bridge 2: >> bus range: 0x20~0x4f. >> segment: 0. > > "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." > > Acked-by: Lorenzo Pieralisi <[email protected]>
Hi Lorenzo, Thanks for your view. I will modify the commit message and post a new version patch. Regards, Zhou > >> Signed-off-by: Zhou Wang <[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 b5b376e..46a3e32 100644 >> --- a/drivers/acpi/pci_mcfg.c >> +++ b/drivers/acpi/pci_mcfg.c >> @@ -40,11 +40,10 @@ phys_addr_t pci_mcfg_lookup(u16 seg, struct resource >> *bus_res) >> struct mcfg_entry *e; >> >> /* >> - * 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) >> return e->addr; >> } >> -- >> 1.9.1 >> > > . >
