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>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/msi.h b/include/linux/msi.h
index 271dfd14a05f..090ddadbc838 100644
--- 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 */