Yijing,

On 09/12/14 11:57, Yijing Wang wrote:

quoted

quoted

quoted

+void __weak pcibios_set_phb_msi_domain(struct pci_bus *bus)
+{
+}
+
+static void pci_set_bus_msi_domain(struct pci_bus *bus)
+{
+	struct pci_dev *bridge = bus->self;
+
+	if (!bridge)
+		pcibios_set_phb_msi_domain(bus);
+	else
+		dev_set_msi_domain(&bus->dev, dev_get_msi_domain(&bridge->dev));
+}

Hi Marc, we can not assume pci devices under same phb share the same msi irq domain,
now in x86, pci devices under the same phb may associate different msi irq domain.

Hi Marc,

quoted

Well, this is not supposed to be a perfect solution yet, but instead a
basis for discussion. What I'd like to find out is:

- What is the minimum granularity for associating a device with its MSI
domain in existing platforms?

PCI device, after Gerry's msi irq domain patchset which now in linux-next,
in x86, we will find msi irq domain by pci_dev.

Are you *really* associating the MSI domain on a per pci-device basis?
That is, you have devices on the same PCI bus talking to different MSI hw?

I generally agree your first patch which associate basic device with msi irq domain.

quoted

- What topology data structures do you use to find out what MSI
controller a device should be matched with?

Now only arm and arm64 use msi controller to setup/teardown msi irqs,
in arm, now msi controller saved in pci_sys_data, and for arm64, it seems
to be saved in pci_bus. For a more common method to find msi controller/irq domain,
I prefer pci_dev/device.

Forget about msi_controller, the whole goal of this series is to make it
obsolete. On your x86 platform, what how do you identify which MSI
domain should be associated with a given PCI device? Surely you must
have a set of data structures or ACPI tables which give you that
information.

quoted

- What in-tree platform already has this requirements?

As mentioned above, x86 does.

Let me rephrase that in a non-ambiguous manner: can you point me to a
file implementing this in mainline?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...