[PATCH v4 1/5] PCI: Add pci_bus_fixup_irqs().

Bjorn Helgaas
2015-10-07T19:44:26Z

Hi David,

On Fri, Oct 02, 2015 at 11:43:59AM -0700, David Daney wrote:
> From: David Daney <david.daney@cavium.com>
>
> pci_bus_fixup_irqs() works like pci_fixup_irqs(), except it only does
> the fixups for devices on the specified bus.
>
> Follow-on patch will use the new function.
>
> Signed-off-by: David Daney <david.daney@cavium.com>
> ---
> No change from v2.
>
> drivers/pci/setup-irq.c | 30 ++++++++++++++++++++++++++++++
> include/linux/pci.h | 4 ++++
> 2 files changed, 34 insertions(+)
>
> diff --git a/drivers/pci/setup-irq.c b/drivers/pci/setup-irq.c
> index 95c225b..189ad17 100644
> --- a/drivers/pci/setup-irq.c
> +++ b/drivers/pci/setup-irq.c
> @@ -66,3 +66,33 @@ void pci_fixup_irqs(u8 (*swizzle)(struct pci_dev *, u8 *),
> pdev_fixup_irq(dev, swizzle, map_irq);
> }
> EXPORT_SYMBOL_GPL(pci_fixup_irqs);
> +
> +struct pci_bus_fixup_cb_info {
> + u8 (*swizzle)(struct pci_dev *, u8 *);
> + int (*map_irq)(const struct pci_dev *, u8, u8);
> +};
> +
> +static int pci_bus_fixup_irq_cb(struct pci_dev *dev, void *arg)
> +{
> + struct pci_bus_fixup_cb_info *info = arg;
> +
> + pdev_fixup_irq(dev, info->swizzle, info->map_irq);
> + return 0;
> +}
> +
> +/*
> + * Fixup the irqs only for devices on the given bus using supplied
> + * swizzle and map_irq function pointers
> + */
> +void pci_bus_fixup_irqs(struct pci_bus *bus,
> + u8 (*swizzle)(struct pci_dev *, u8 *),
> + int (*map_irq)(const struct pci_dev *, u8, u8))
> +{
> + struct pci_bus_fixup_cb_info info;
> +
> + info.swizzle = swizzle;
> + info.map_irq = map_irq;
> + pci_walk_bus(bus, pci_bus_fixup_irq_cb, &info);

I don't like the existing pci_fixup_irqs(), so by transitivity, I
don't like pci_bus_fixup_irqs() either. The problem is that in both
cases this is a one-time pass over the tree, so we don't handle
hot-added devices correctly.

I think we need to get rid of pci_fixup_irqs() and somehow integrate
it into the pci_device_add() path, where it would be done once for
every device we enumerate. If we did that, I don't think you would
need to add pci_bus_fixup_irqs(), would you?

Bjorn

> +
> +}
> +EXPORT_SYMBOL_GPL(pci_bus_fixup_irqs);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index e90eb22..b505b50 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1120,6 +1120,10 @@ void pdev_enable_device(struct pci_dev *);
> int pci_enable_resources(struct pci_dev *, int mask);
> void pci_fixup_irqs(u8 (*)(struct pci_dev *, u8 *),
> int (*)(const struct pci_dev *, u8, u8));
> +void pci_bus_fixup_irqs(struct pci_bus *,
> + u8 (*)(struct pci_dev *, u8 *),
> + int (*)(const struct pci_dev *, u8, u8));
> +
> #define HAVE_PCI_REQ_REGIONS 2
> int __must_check pci_request_regions(struct pci_dev *, const char *);
> int __must_check pci_request_regions_exclusive(struct pci_dev *, const char *);
> --
> 1.9.1
>
> --
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