[PATCH V2 1/2] PCI: Add new pci_ops for setting MSI parent for PCI bus

From: suravee.suthikulpanit
Date: Tue Nov 11 2014 - 14:18:34 EST


From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>

In the pci_scan_root_bus, pci_bus is created and passed down to:
pci_scan_child_bus
pci_scan_bridge
pci_add_new_bus
pci_alloc_child_bus

In pci_alloc_child_bus, the parent's msi_chip is propagated to child,
and the referenced by PCI devices when calling arch_setup_msi_irq().

However, in the current implementation of pci_scan_root_bus, the msi_chip
of the root_bus is not set before handing off to pci_scan_child_bus.

This patch proposes a new callback function in the struct pci_ops
to allow host controller to provide a call back for specifying
msi_chip to be used.

Cc: Bjorn Helgass <bhelgaas@xxxxxxxxxx>
Cc: Liviu Dudau <liviu.dudau@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
---
drivers/pci/probe.c | 3 +++
include/linux/pci.h | 1 +
2 files changed, 4 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5ed9930..cf7114d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2081,6 +2081,9 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
if (!b)
return NULL;

+ if (ops->set_msi_parent)
+ ops->set_msi_parent(b);
+
if (!found) {
dev_info(&b->dev,
"No busn resource found for root bus, will use [bus %02x-ff]\n",
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5be8db4..6093544 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -560,6 +560,7 @@ static inline int pcibios_err_to_errno(int err)
struct pci_ops {
int (*read)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val);
int (*write)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val);
+ int (*set_msi_parent)(struct pci_bus *bus);
};

/*
--
1.9.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/