On Thu, Feb 11, 2016 at 11:58:53AM +0000, Lorenzo Pieralisi wrote:
On Thu, Feb 04, 2016 at 06:29:00PM +0100, Tomasz Nowicki wrote:
This is the last step before enabling generic ACPI PCI host controller for ARM64. We need to take care of legacy IRQ mapping for non-MSI(X) PCI devices. pcibios_enable_device() boot order is not sensitive to ACPI device enumeration, so it is the best place to assign device's IRQs.
I guess you are referring to:
https://lists.linaro.org/pipermail/linaro-acpi/2015-October/005944.html
It is weird that the dependency can't be enforced, I will have a look into this, it would be nice to have DT and ACPI legacy IRQs mapping confined in pcibios_add_device() so that we can remove them in one go when Matthew's series is merged.
One option, that is not ideal but has the merit of setting the stage for pcibios_enable_device() AND pcibios_add_device() removal, is to add IRQ mapping (by adding the call) in a pcibios_alloc_irq() callback (if Bjorn does not remove it from core code before we manage to add it, I think he is only reverting the x86 version).
https://lkml.org/lkml/2016/2/9/648
That's called at device probe time, it should not change DT probing path (unless we use the irq number before the device is probed, which I doubt) and should allow the ACPI scan handlers to be installed so that the ACPI IRQ mapping can be effectively carried out.
pcibios_alloc_irq() replaces pcibios_add_device().
When Matthew's patchset lands in mainline, pcibios_alloc_irq() will be removed too (at least we have a place where all legacy IRQ mappings are carried out and I can obliterate it easily).
Other option is to change ACPI core code, I see no other way.
Tested on KVM PCI host generic (that uses pci_fixup_irqs() so it does not really count for DT).
Here (on top of your series), ready for flak.
Lorenzo
-- >8 -- diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index 0b53262..26ee291 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -45,28 +45,23 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, */ int pcibios_enable_device(struct pci_dev *dev, int mask) { - int ret; - if (pci_has_flag(PCI_PROBE_ONLY)) return 0;
- ret = pci_enable_resources(dev, mask); - if (ret < 0) - return ret; - -#ifdef CONFIG_ACPI - if (!pci_dev_msi_enabled(dev)) - return acpi_pci_irq_enable(dev); -#endif - return 0; + return pci_enable_resources(dev, mask); }
/* - * Try to assign the IRQ number from DT when adding a new device + * Try to assign the IRQ number when probing a new device */ -int pcibios_add_device(struct pci_dev *dev) +int pcibios_alloc_irq(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 + return acpi_pci_irq_enable(dev); +#endif
return 0; }