On 11/8/22 5:15 AM, Bjorn Helgaas wrote:
> Capitalize subject line to match other commits:
>
> 930c6074d7dd ("PCI: loongson: Work around LS7A incorrect Interrupt Pin registers")
> 2410e3301fcc ("PCI: loongson: Don't access non-existent devices")
> cd89edda4002 ("PCI: loongson: Add ACPI init support")
> dee449aafd48 ("PCI: loongson: Use generic 8/16/32-bit config ops on LS2K/LS7A")
>
OK, I will do this in the next version patch.
> On Fri, Nov 04, 2022 at 06:53:40PM +0800, Liu Peibao wrote:
>> The PCI Controller of 2k1000 could not mask devices by
>> setting vender id or device id in configuration space header
>> as invalid values. When there are pins shareble between
>> the platform device and PCI device, if the platform device
>> is preferred, we should not scan this PCI device. In the
>> above scene, add `status = "disabled"` property in DT node
>> of this PCI device.
>
> Rewrap this to fill 75 columns.
> > s/id/ID/
> s/shareble/shareable/
>
OK, I will take care in the next version patch.
>> Signed-off-by: Liu Peibao <liupeibao@xxxxxxxxxxx>
>> ---
>> V2 -> V3: 1. use list_for_each_entry() for more clearly.
>> 2. fix wrong use of sizeof().
>> V1 -> V2: use existing property "status" instead of adding new property.
>>
>>
>> drivers/pci/controller/pci-loongson.c | 55 +++++++++++++++++++++++++++
>> 1 file changed, 55 insertions(+)
>>
>> diff --git a/drivers/pci/controller/pci-loongson.c b/drivers/pci/controller/pci-loongson.c
>> index 05c50408f13b..c7dd88eac885 100644
>> --- a/drivers/pci/controller/pci-loongson.c
>> +++ b/drivers/pci/controller/pci-loongson.c
>> @@ -40,11 +40,21 @@ struct loongson_pci_data {
>> struct pci_ops *ops;
>> };
>>
>> +#ifdef CONFIG_OF
>> +struct mask_entry {
>> + struct list_head entry;
>> + unsigned int devfn;
>> +};
>> +#endif
>> +
>> struct loongson_pci {
>> void __iomem *cfg0_base;
>> void __iomem *cfg1_base;
>> struct platform_device *pdev;
>> const struct loongson_pci_data *data;
>> +#ifdef CONFIG_OF
>> + struct list_head masklist;
>> +#endif
>> };
>>
>> /* Fixup wrong class code in PCIe bridges */
>> @@ -194,6 +204,18 @@ static void __iomem *pci_loongson_map_bus(struct pci_bus *bus,
>> return NULL;
>> }
>>
>> +#ifdef CONFIG_OF
>> + /* Don't access devices in masklist */
>> + if (pci_is_root_bus(bus)) {
>> + struct mask_entry *entry;
>> +
>> + list_for_each_entry(entry, &priv->masklist, entry) {
>> + if (devfn == entry->devfn)
>> + return NULL;
>> + }
>> + }
>> +#endif
>
> I would probably get rid of the masklist and just search for a disabled
> property when reading config offset 0 (vendor ID). That's not a
> performance path anyway. And this seems similar to the
> FLAG_DEV_HIDDEN path where you probably don't need to do it for all
> controllers.
>
Thanks for your idea! This really helps a lot!
I will follow your idea and rework it.
Yes, this is similar to the FLAG_DEV_HIDDEN path and currently, this path
is only needed by 2K1000 PCI controller.
BR,
Peibao
