[PATCHv5 04/11] PCI: Introduce new MSI chip infrastructure

[Thierry Reding]

On Mon, Jul 15, 2013 at 01:52:40PM +0200, Thomas Petazzoni wrote:
> From: Thierry Reding <thierry.reding at avionic-design.de>
> 
> 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 at avionic-design.de>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
>  drivers/pci/msi.c   | 27 +++++++++++++++++++++++++--
>  drivers/pci/probe.c |  1 +
>  include/linux/msi.h | 11 +++++++++++
>  include/linux/pci.h |  1 +
>  4 files changed, 38 insertions(+), 2 deletions(-)

Bjorn,

We'll need this as part of a stable branch as well, so any chance you
could ack it?

Thierry

> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index aa2f697..d5b6378 100644
> --- 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 46ada5c..b8eaa81 100644
> --- 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 18870b0..cbf5d05 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -64,4 +64,15 @@ void arch_restore_msi_irqs(struct pci_dev *dev, int irq);
>  
>  void default_teardown_msi_irqs(struct pci_dev *dev);
>  
> +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 0fd1f15..4044e3c 100644
> --- 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 */
>  
> -- 
> 1.8.1.2
> 
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