PCI: Introduce new MSI chip infrastructure

The new struct msi_chip is used to associated an MSI controller with a
PCI bus. It is automatically handed down from the root to its children
during bus enumeration.

This patch provides default (weak) implementations for the architecture-
specific MSI functions (arch_setup_msi_irq(), arch_teardown_msi_irq()
and arch_msi_check_device()) which check if a PCI device's bus has an
attached MSI chip and forward the call appropriately.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Daniel Price <daniel.price@gmail.com>
Tested-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 823c3861c4d8c2e7284de65f0d2f624c3cc7e7b3..2837285c4e8327185f934390975475ff76d7678f 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -32,16 +32,39 @@ static int pci_msi_enable = 1;
 
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-       return -EINVAL;
+       struct msi_chip *chip = dev->bus->msi;
+       int err;
+
+       if (!chip || !chip->setup_irq)
+               return -EINVAL;
+
+       err = chip->setup_irq(chip, dev, desc);
+       if (err < 0)
+               return err;
+
+       irq_set_chip_data(desc->irq, chip);
+
+       return 0;
 }
 
 void __weak arch_teardown_msi_irq(unsigned int irq)
 {
+       struct msi_chip *chip = irq_get_chip_data(irq);
+
+       if (!chip || !chip->teardown_irq)
+               return;
+
+       chip->teardown_irq(chip, irq);
 }
 
 int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
 {
-       return 0;
+       struct msi_chip *chip = dev->bus->msi;
+
+       if (!chip || !chip->check_device)
+               return 0;
+
+       return chip->check_device(chip, dev, nvec, type);
 }
 
 int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 46ada5c098ebed710f24a7deb426720149b219fd..b8eaa81678490921493213f796faf923324e961d 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -666,6 +666,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 
        child->parent = parent;
        child->ops = parent->ops;
+       child->msi = parent->msi;
        child->sysdata = parent->sysdata;
        child->bus_flags = parent->bus_flags;
 

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 271dfd14a05fafdb9bce2ec401ce475c2ba96920..090ddadbc838279596dea0c8d22351a64867dc03 100644 (file)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -65,4 +65,15 @@ void arch_restore_msi_irqs(struct pci_dev *dev, int irq);
 void default_teardown_msi_irqs(struct pci_dev *dev);
 void default_restore_msi_irqs(struct pci_dev *dev, int irq);
 
+struct msi_chip {
+       struct module *owner;
+       struct device *dev;
+
+       int (*setup_irq)(struct msi_chip *chip, struct pci_dev *dev,
+                        struct msi_desc *desc);
+       void (*teardown_irq)(struct msi_chip *chip, unsigned int irq);
+       int (*check_device)(struct msi_chip *chip, struct pci_dev *dev,
+                           int nvec, int type);
+};
+
 #endif /* LINUX_MSI_H */

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0fd1f1582fa1cdf359b33f3cddeaa60026f492ac..4044e3c00609b7498766a67d216dd20ef3f9ece2 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -433,6 +433,7 @@ struct pci_bus {
        struct resource busn_res;       /* bus numbers routed to this bus */
 
        struct pci_ops  *ops;           /* configuration access functions */
+       struct msi_chip *msi;           /* MSI controller */
        void            *sysdata;       /* hook for sys-specific extension */
        struct proc_dir_entry *procdir; /* directory entry in /proc/bus/pci */