[Patch v2 1/4] PCI: Add hooks to allocate/free IRQ resources when binding/unbinding driver

Jiang Liu
2015-06-02T02:47:38Z

Add two hook points pcibios_{alloc|free}_irq() into PCI core, which will
be called when binding/unbinding PCI device drivers. Then PCI arch code
may hook into these two points to allocate IRQ resources on demand and
free them when not used anymore.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/pci/pci-driver.c | 26 ++++++++++++++++++++------
include/linux/pci.h | 2 ++
2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 3cb2210de553..450ad36ffc77 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -388,18 +388,31 @@ static int __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev)
return error;
}

+int __weak pcibios_alloc_irq(struct pci_dev *dev)
+{
+ return dev->irq;
+}
+
+void __weak pcibios_free_irq(struct pci_dev *dev)
+{
+}
+
static int pci_device_probe(struct device *dev)
{
- int error = 0;
- struct pci_driver *drv;
- struct pci_dev *pci_dev;
+ int error;
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct pci_driver *drv = to_pci_driver(dev->driver);
+
+ error = pcibios_alloc_irq(pci_dev);
+ if (error < 0)
+ return error;

- drv = to_pci_driver(dev->driver);
- pci_dev = to_pci_dev(dev);
pci_dev_get(pci_dev);
error = __pci_device_probe(drv, pci_dev);
- if (error)
+ if (error) {
+ pcibios_free_irq(pci_dev);
pci_dev_put(pci_dev);
+ }

return error;
}
@@ -415,6 +428,7 @@ static int pci_device_remove(struct device *dev)
drv->remove(pci_dev);
pm_runtime_put_noidle(dev);
}
+ pcibios_free_irq(pci_dev);
pci_dev->driver = NULL;
}

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8dc4c6e..f50d16a04abc 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1656,6 +1656,8 @@ int pcibios_set_pcie_reset_state(struct pci_dev *dev,
int pcibios_add_device(struct pci_dev *dev);
void pcibios_release_device(struct pci_dev *dev);
void pcibios_penalize_isa_irq(int irq, int active);
+int pcibios_alloc_irq(struct pci_dev *dev);
+void pcibios_free_irq(struct pci_dev *dev);

#ifdef CONFIG_HIBERNATE_CALLBACKS
extern struct dev_pm_ops pcibios_pm_ops;
--
1.7.10.4