Re: [PATCH V1 11/11] arm64, pci, acpi: Support for ACPI based PCI hostbridge init

[Tomasz Nowicki <tomasz.nowicki@linaro.org>]

On 03.11.2015 17:55, Lorenzo Pieralisi wrote:
> On Tue, Oct 27, 2015 at 05:38:42PM +0100, Tomasz Nowicki wrote:
>
> [...]
>
>>   menu "Kernel Features"
>> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
>> index b3d098b..66cc1ae 100644
>> --- a/arch/arm64/kernel/pci.c
>> +++ b/arch/arm64/kernel/pci.c
>> @@ -11,12 +11,15 @@
>>    */
>>
>>   #include <linux/acpi.h>
>> +#include <linux/ecam.h>
>>   #include <linux/init.h>
>>   #include <linux/io.h>
>>   #include <linux/kernel.h>
>>   #include <linux/mm.h>
>> +#include <linux/of_address.h>
>>   #include <linux/of_pci.h>
>>   #include <linux/of_platform.h>
>> +#include <linux/pci-acpi.h>
>>   #include <linux/slab.h>
>>
>>   #include <asm/pci-bridge.h>
>> @@ -52,35 +55,216 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
>>   }
>>
>>   /*
>> - * Try to assign the IRQ number from DT when adding a new device
>> + * Try to assign the IRQ number from DT/ACPI when adding a new device
>>    */
>>   int pcibios_add_device(struct pci_dev *dev)
>>   {
>> -	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
>> +	if (acpi_disabled)
>> +		dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
>> +#ifdef CONFIG_ACPI
>> +	else
>> +		acpi_pci_irq_enable(dev);
>> +#endif
>
> This series:
>
> http://www.spinics.net/lists/linux-pci/msg45950.html
>
> will allow us to initialize the irq mapping function according to
> the boot method, code above is getting cumbersome and it is already
> overriden when booting with DT, so we will remove it altogether.
>
>>
>>   	return 0;
>>   }
>>
>> +#ifdef CONFIG_ACPI
>> +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
>> +{
>> +	struct acpi_pci_root *root = bridge->bus->sysdata;
>> +
>> +	ACPI_COMPANION_SET(&bridge->dev, root->device);
>> +	return 0;
>
> This should be made part of core code IMO.
>
>> +}
>> +
>> +void pcibios_add_bus(struct pci_bus *bus)
>> +{
>> +	acpi_pci_add_bus(bus);
>> +}
>> +
>> +void pcibios_remove_bus(struct pci_bus *bus)
>> +{
>> +	acpi_pci_remove_bus(bus);
>> +}
>
> Two functions above are identical for arm64, ia64 and x86, I do
> not think they belong in arch code.
>
>> +static int __init pcibios_assign_resources(void)
>> +{
>> +	if (acpi_disabled)
>> +		return 0;
>> +
>> +	pci_assign_unassigned_resources();
>> +	return 0;
>
> Already commented on this.
>
>> +}
>>   /*
>> - * raw_pci_read/write - Platform-specific PCI config space access.
>> + * rootfs_initcall comes after subsys_initcall and fs_initcall_sync,
>> + * so we know acpi scan and PCI_FIXUP_FINAL quirks have both run.
>>    */
>> -int raw_pci_read(unsigned int domain, unsigned int bus,
>> -		  unsigned int devfn, int reg, int len, u32 *val)
>> +rootfs_initcall(pcibios_assign_resources);
>> +
>> +static void __iomem *
>> +pci_mcfg_dev_base(struct pci_bus *bus, unsigned int devfn, int offset)
>>   {
>> -	return -ENXIO;
>> +	struct pci_mmcfg_region *cfg;
>> +
>> +	cfg = pci_mmconfig_lookup(pci_domain_nr(bus), bus->number);
>> +	if (cfg && cfg->virt)
>> +		return cfg->virt +
>> +			(PCI_MMCFG_BUS_OFFSET(bus->number) | (devfn << 12)) +
>> +			offset;
>> +	return NULL;
>
> Why is this code arm64 specific ?

It is not, I will move it out of here, probably to mcfg.c file where we 
can apply quirks.

Thanks,
Tomasz