[PATCHv5 05/11] of: pci: add registry of MSI chips
Grant Likely
grant.likely at secretlab.ca
Sun Jul 28 00:33:10 EDT 2013
On Mon, 15 Jul 2013 11:12:42 -0500, Rob Herring <robherring2 at gmail.com> wrote:
> On 07/15/2013 06:52 AM, Thomas Petazzoni wrote:
> > This commit adds a very basic registry of msi_chip structures, so that
> > an IRQ controller driver can register an msi_chip, and a PCIe host
> > controller can find it, based on a 'struct device_node'.
> >
> > Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
>
> Acked-by: Rob Herring <rob.herring at calxeda.com>
Actually, I'm going to disagree on this one and say NAK. I don't think
it is a good idea to create a completely separate registry of msi_chips
for binding to dt nodes. I think it would be better to include the
msi_chip pointer directly into the irq_domain which has to be there
anyway. It then becomes another feature for irq controllers if it can
support doing MSI.
In fact, I would even go so far as to say it would make sense for the
msi_chip functionality to be rolled directly into the irq_domain without
a separate structure; but I'm not nacking on that point.
g.
>
>
> > ---
> > drivers/of/of_pci.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
> > include/linux/msi.h | 2 ++
> > include/linux/of_pci.h | 12 ++++++++++++
> > 3 files changed, 59 insertions(+)
> >
> > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> > index 42c687a..e5ca008 100644
> > --- a/drivers/of/of_pci.c
> > +++ b/drivers/of/of_pci.c
> > @@ -89,3 +89,48 @@ int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
> > return 0;
> > }
> > EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
> > +
> > +#ifdef CONFIG_PCI_MSI
> > +
> > +static LIST_HEAD(of_pci_msi_chip_list);
> > +static DEFINE_MUTEX(of_pci_msi_chip_mutex);
> > +
> > +int of_pci_msi_chip_add(struct msi_chip *chip)
> > +{
> > + if (!of_property_read_bool(chip->of_node, "msi-controller"))
> > + return -EINVAL;
> > +
> > + mutex_lock(&of_pci_msi_chip_mutex);
> > + list_add(&chip->list, &of_pci_msi_chip_list);
> > + mutex_unlock(&of_pci_msi_chip_mutex);
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
> > +
> > +void of_pci_msi_chip_remove(struct msi_chip *chip)
> > +{
> > + mutex_lock(&of_pci_msi_chip_mutex);
> > + list_del(&chip->list);
> > + mutex_unlock(&of_pci_msi_chip_mutex);
> > +}
> > +EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
> > +
> > +struct msi_chip *of_pci_find_msi_chip_by_node(struct device_node *of_node)
> > +{
> > + struct msi_chip *c;
> > +
> > + mutex_lock(&of_pci_msi_chip_mutex);
> > + list_for_each_entry(c, &of_pci_msi_chip_list, list) {
> > + if (c->of_node == of_node) {
> > + mutex_unlock(&of_pci_msi_chip_mutex);
> > + return c;
> > + }
> > + }
> > + mutex_unlock(&of_pci_msi_chip_mutex);
> > +
> > + return NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
> > +
> > +#endif /* CONFIG_PCI_MSI */
> > diff --git a/include/linux/msi.h b/include/linux/msi.h
> > index cbf5d05..80900e0 100644
> > --- a/include/linux/msi.h
> > +++ b/include/linux/msi.h
> > @@ -67,6 +67,8 @@ void default_teardown_msi_irqs(struct pci_dev *dev);
> > struct msi_chip {
> > struct module *owner;
> > struct device *dev;
> > + struct device_node *of_node;
> > + struct list_head list;
> >
> > int (*setup_irq)(struct msi_chip *chip, struct pci_dev *dev,
> > struct msi_desc *desc);
> > diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
> > index 7a04826..29631eb 100644
> > --- a/include/linux/of_pci.h
> > +++ b/include/linux/of_pci.h
> > @@ -2,6 +2,7 @@
> > #define __OF_PCI_H
> >
> > #include <linux/pci.h>
> > +#include <linux/msi.h>
> >
> > struct pci_dev;
> > struct of_irq;
> > @@ -13,4 +14,15 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
> > int of_pci_get_devfn(struct device_node *np);
> > int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
> >
> > +#if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)
> > +int of_pci_msi_chip_add(struct msi_chip *chip);
> > +void of_pci_msi_chip_remove(struct msi_chip *chip);
> > +struct msi_chip *of_pci_find_msi_chip_by_node(struct device_node *of_node);
> > +#else
> > +static inline int of_pci_msi_chip_add(struct msi_chip *chip) { return -EINVAL; }
> > +static inline void of_pci_msi_chip_remove(struct msi_chip *chip) { }
> > +static inline struct msi_chip *
> > +of_pci_find_msi_chip_by_node(struct device_node *of_node) { return NULL };
> > +#endif
> > +
> > #endif
> >
>
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