Re: [PATCH V3 2/6] acpi: pci: Setup MSI domain for ACPI based pci devices

From: Tomasz Nowicki
Date: Sun Dec 06 2015 - 13:03:28 EST


Hi Marc,


On 11/22/2015 12:35 PM, Marc Zyngier wrote:
On Sat, 21 Nov 2015 15:18:45 -0600
Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> wrote:

Hi Marc,

On 11/19/15 06:08, Marc Zyngier wrote:
On Wed, 21 Oct 2015 11:47:25 -0700
Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx> wrote:

Hi Suravee,

Sorry it took so long to get to this series. Comments below.
No worry.

This patch introduces pci_host_bridge_acpi_msi_domain(), which returns
the MSI domain of the specified PCI host bridge with DOMAIN_BUS_PCI_MSI
bus token. Then, it is assigned to pci device.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
---
drivers/pci/pci-acpi.c | 13 +++++++++++++
drivers/pci/probe.c | 2 ++
include/linux/pci.h | 7 +++++++
3 files changed, 22 insertions(+)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index a32ba75..0e21ef4 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -9,7 +9,9 @@

#include <linux/delay.h>
#include <linux/init.h>
+#include <linux/irqdomain.h>
#include <linux/pci.h>
+#include <linux/msi.h>
#include <linux/pci_hotplug.h>
#include <linux/module.h>
#include <linux/pci-aspm.h>
@@ -689,6 +691,17 @@ static struct acpi_bus_type acpi_pci_bus = {
.cleanup = pci_acpi_cleanup,
};

+struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
+{
+ struct irq_domain *dom = NULL;
+ struct fwnode_handle *fwnode = pci_msi_get_fwnode(&bus->dev);
+
+ if (fwnode)
+ dom = irq_find_matching_fwnode(fwnode,
+ DOMAIN_BUS_PCI_MSI);
+ return dom;
+}
+
Given this, I really question the need for what you define in patch #1
to be standalone. It is only used by ACPI (DT has its own private
helpers), and it is so far unlikely that it will be of any use for
other firmware interfaces.

My suggestion is to get rid of pci_msi_get_fwnode() and move the
registration helper into this file. That'd be much simpler.

Thanks,

M.

Ok, I'll take care of this. I assume the rest of the patches looks ok.
I still need to finish going through it (I have minor comments so far
on some of the other patches), but I want to get the core ACPI stuff in
shape before doing anything else.
I am trying to do similar thing for GICv3 & ITS, can you please have a look:
http://lkml.iu.edu/hypermail/linux/kernel/1510.1/06139.html

Can you please explain what ACPI core changes do you mean?

Regards,
Tomasz
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