Re: [PATCH 13/18] Delayed sparc setup of PCI IRQs to bus scan time

[Bjorn Helgaas <bhelgaas@google.com>]

On Thu, Oct 02, 2014 at 05:07:41AM +0100, matt@masarand.com wrote:
> From: Matthew Minter <matt@masarand.com>
> 
> Currently sparc allocates PCI IRQs through several different methods
> based on device. This is done during the boot stage and faces a draw-back
> by which hot-plugged devices will not be allocated an IRQ, this is fixed
> by registering IRQ allocation functions for later use during the device
> enable path.
> 
> Signed-off-by: Matthew Minter <matt@masarand.com>
> 
> ---
>  arch/sparc/kernel/leon_pci.c | 12 +++++++++++-
>  arch/sparc/kernel/pci.c      | 21 +++++++++++++++++----
>  2 files changed, 28 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/sparc/kernel/leon_pci.c b/arch/sparc/kernel/leon_pci.c
> index 899b720..1079eb7 100644
> --- a/arch/sparc/kernel/leon_pci.c
> +++ b/arch/sparc/kernel/leon_pci.c
> @@ -13,6 +13,8 @@
>  #include <asm/leon.h>
>  #include <asm/leon_pci.h>
>  
> +int (*leon_pci_map_irq)(const struct pci_dev *dev, u8 slot, u8 pin);
> +
>  /* The LEON architecture does not rely on a BIOS or bootloader to setup
>   * PCI for us. The Linux generic routines are used to setup resources,
>   * reset values of configuration-space register settings are preserved.
> @@ -36,7 +38,7 @@ void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
>  				     &resources);
>  	if (root_bus) {
>  		/* Setup IRQs of all devices using custom routines */
> -		pci_fixup_irqs(pci_common_swizzle, info->map_irq);
> +		leon_pci_map_irq = info->map_irq;
>  
>  		/* Assign devices with resources */
>  		pci_assign_unassigned_resources();
> @@ -45,6 +47,14 @@ void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
>  	}
>  }
>  
> +int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
> +{
> +	bridge->swizzle_irq = pci_common_swizzle;
> +	bridge->map_irq = leon_pci_map_irq;
> +	return 0;
> +}
> +
> +
>  void pcibios_fixup_bus(struct pci_bus *pbus)
>  {
>  	struct pci_dev *dev;
> diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
> index b36365f..7361c52 100644
> --- a/arch/sparc/kernel/pci.c
> +++ b/arch/sparc/kernel/pci.c
> @@ -340,10 +340,6 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
>  	} else {
>  		dev->hdr_type = PCI_HEADER_TYPE_NORMAL;
>  		dev->rom_base_reg = PCI_ROM_ADDRESS;
> -
> -		dev->irq = sd->op->archdata.irqs[0];
> -		if (dev->irq == 0xffffffff)
> -			dev->irq = PCI_IRQ_NONE;
>  	}
>  
>  	pci_parse_of_addrs(sd->op, node, dev);
> @@ -356,6 +352,23 @@ static struct pci_dev *of_create_pci_dev(struct pci_pbm_info *pbm,
>  	return dev;
>  }
>  
> +int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
> +{
> +	int irq;
> +	struct platform_device *op = of_find_device_by_node(dev->sysdata);

Add a blank line here.

> +	irq = op->archdata.irqs[0];
> +	if (irq == 0xffffffff)
> +		irq = PCI_IRQ_NONE;
> +	return irq;
> +}
> +
> +int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)

Shouldn't be weak.  I see why you're doing it, since you added a non-weak
version in leon_pci.c, but without leon_pci.c, we'll have two weak versions
(this one and the one in drivers/pci/probe.c), and it's not clear which one
will be used.  Maybe keep this implementation (non-weak), and make a global
map_irq pointer that defaults to pci_map_irq() and leon_pci.c would
override that?

> +{
> +	bridge->swizzle_irq = NULL;
> +	bridge->map_irq = pci_map_irq;
> +	return 0;
> +}
> +
>  static void apb_calc_first_last(u8 map, u32 *first_p, u32 *last_p)
>  {
>  	u32 idx, first, last;
> -- 
> 2.1.0
>