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 <lorenzo.pieralisi@xxxxxxx>
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 <wangzhou1@xxxxxxxxxxxxx>
>> ---
>> 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
>>
>
> .
>
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