Messages in this thread | | | Date | Thu, 01 Oct 2015 10:24:44 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH v3 3/4] PCI/MSI: Add helper function pci_msi_domain_get_msi_rid(). |
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Hi David,
On 30/09/15 23:47, David Daney wrote: > From: David Daney <david.daney@cavium.com> > > Add pci_msi_domain_get_msi_rid() to return the MSI requester id (RID). > Initially needed by gic-v3 based systems. It will be used by follow on > patch to drivers/irqchip/irq-gic-v3-its-pci-msi.c > > Initially supports mapping the RID via OF device tree. In the future, > this could be extended to use ACPI _IORT tables as well. > > Signed-off-by: David Daney <david.daney@cavium.com> > --- > drivers/pci/msi.c | 31 +++++++++++++++++++++++++++++++ > include/linux/msi.h | 1 + > 2 files changed, 32 insertions(+) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index d449714..92b6dc9 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -20,6 +20,7 @@ > #include <linux/io.h> > #include <linux/slab.h> > #include <linux/irqdomain.h> > +#include <linux/of_irq.h> > > #include "pci.h" > > @@ -1327,4 +1328,34 @@ struct irq_domain *pci_msi_create_default_irq_domain(struct device_node *node, > > return domain; > } > + > +struct get_mis_id_data { > + u32 alias; > +}; > + > +static int get_msi_id_cb(struct pci_dev *pdev, u16 alias, void *data) > +{ > + struct get_mis_id_data *s = data; > + > + s->alias = alias; > + return 0; > +}
Why not use a naked u32, since you only have a single field in this structure? Or is it that you are anticipating other fields there?
> +/** > + * pci_msi_domain_get_msi_rid - Get the MSI requester id (RID) > + * @domain: The interrupt domain > + * @pdev: The PCI device. > + * > + * The RID for a device is formed from the alias, with a firmware > + * supplied mapping applied > + * > + * Returns: The RID. > + */ > +u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev) > +{ > + struct get_mis_id_data d; > + > + d.alias = 0; > + pci_for_each_dma_alias(pdev, get_msi_id_cb, &d); > + return of_msi_map_rid(&pdev->dev, domain->of_node, d.alias);
Should you check whether domain->of_node is NULL first? I don't think of_msi_map_rid would have any problem with that, but a domain that is not backed by an of_node makes me feel a bit uneasy and would tend to indicate that we're not using DT.
> +} > #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */ > diff --git a/include/linux/msi.h b/include/linux/msi.h > index ad939d0..56e3b76 100644 > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -293,6 +293,7 @@ irq_hw_number_t pci_msi_domain_calc_hwirq(struct pci_dev *dev, > struct msi_desc *desc); > int pci_msi_domain_check_cap(struct irq_domain *domain, > struct msi_domain_info *info, struct device *dev); > +u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev); > #endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */ > > #endif /* LINUX_MSI_H */ >
Otherwise looks good to me.
Thanks,
M. -- Jazz is not dead. It just smells funny...
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