Commit 0cbdcfcf authored by Thierry Reding's avatar Thierry Reding Committed by Jason Cooper
Browse files

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: default avatarThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarDaniel Price <daniel.price@gmail.com>
Tested-by: default avatarThierry Reding <thierry.reding@gmail.com>
Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent ebd97be6

drivers/pci/msi.c

+25 −2
Original line number Diff line number Diff line
@@ -32,16 +32,39 @@ static int pci_msi_enable = 1; 


int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)

{

	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)

{

	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)

drivers/pci/probe.c

+1 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/msi.h

+11 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

CRA Git | Maintained and supported by SUSTech CRA and CCSE