[04/18] Delayed powerpc setup of PCI IRQs to bus scan time

From: Matthew Minter <matt@masarand.com>

The powerpc PCI init code is currently initialising PCI device IRQ during
the boot time pcibios phase. This results in devices which are connected
after boot time not being asigned IRQs which can cause various problems.

This patch as part of its set fixes this be moving the IRQ initialisation
into the PCI device enable code path so that it is run for boot time and
hot-plugged devices alike.

Signed-off-by: Matthew Minter <matt@masarand.com>

---
 arch/powerpc/kernel/pci-common.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

On Thu, Oct 02, 2014 at 05:07:32AM +0100, matt@masarand.com wrote:
> From: Matthew Minter <matt@masarand.com>
> 
> The powerpc PCI init code is currently initialising PCI device IRQ during
> the boot time pcibios phase. This results in devices which are connected
> after boot time not being asigned IRQs which can cause various problems.
> 
> This patch as part of its set fixes this be moving the IRQ initialisation
> into the PCI device enable code path so that it is run for boot time and
> hot-plugged devices alike.
> 
> Signed-off-by: Matthew Minter <matt@masarand.com>
> 
> ---
>  arch/powerpc/kernel/pci-common.c | 26 +++++++++++++-------------
>  1 file changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
> index b2814e2..a8be5a5 100644
> --- a/arch/powerpc/kernel/pci-common.c
> +++ b/arch/powerpc/kernel/pci-common.c
> @@ -217,7 +217,7 @@ struct pci_controller* pci_find_hose_for_OF_device(struct device_node* node)
>   * If the interrupt is used, then gets the interrupt line from the
>   * openfirmware and sets it in the pci_dev and pci_config line.
>   */
> -static int pci_read_irq_line(struct pci_dev *pci_dev)
> +static int pci_read_irq_line(struct pci_dev *pci_dev, u8 pin)
>  {
>  	struct of_phandle_args oirq;
>  	unsigned int virq;
> @@ -229,7 +229,7 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
>  #endif
>  	/* Try to get a mapping from the device-tree */
>  	if (of_irq_parse_pci(pci_dev, &oirq)) {
> -		u8 line, pin;
> +		u8 line;
>  
>  		/* If that fails, lets fallback to what is in the config
>  		 * space and map that through the default controller. We
> @@ -238,10 +238,6 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
>  		 * either provide a proper interrupt tree or don't use this
>  		 * function.
>  		 */
> -		if (pci_read_config_byte(pci_dev, PCI_INTERRUPT_PIN, &pin))
> -			return -1;
> -		if (pin == 0)
> -			return -1;
>  		if (pci_read_config_byte(pci_dev, PCI_INTERRUPT_LINE, &line) ||
>  		    line == 0xff || line == 0) {
>  			return -1;
> @@ -266,9 +262,16 @@ static int pci_read_irq_line(struct pci_dev *pci_dev)
>  
>  	pr_debug(" Mapped to linux irq %d\n", virq);
>  
> -	pci_dev->irq = virq;
> +	return virq;
> +}
>  
> -	return 0;
> +int pci_map_irq(struct pci_dev *dev, u8 slot, u8 pin)

Should be static.

> +{
> +	/* Read default IRQs and fixup if necessary */
> +	int irq = pci_read_irq_line(dev, pin);
> +	if (ppc_md.pci_irq_fixup)
> +		ppc_md.pci_irq_fixup(dev);
> +	return irq;

The .pci_irq_fixup() can change dev->irq, so wouldn't you want to return
dev->irq, not irq, here?  Otherwise, pdev_assign_irq() (the caller of
pci_map_irq()) will overwrite the dev->irq value set by the fixup.

>  }
>  
>  /*
> @@ -766,6 +769,8 @@ int pci_proc_domain(struct pci_bus *bus)
>  
>  int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
>  {
> +	bridge->swizzle_irq = NULL;
> +	bridge->map_irq = pci_map_irq;
>  	if (ppc_md.pcibios_root_bridge_prepare)
>  		return ppc_md.pcibios_root_bridge_prepare(bridge);
>  
> @@ -968,11 +973,6 @@ static void pcibios_setup_device(struct pci_dev *dev)
>  	/* Additional platform DMA/iommu setup */
>  	if (ppc_md.pci_dma_dev_setup)
>  		ppc_md.pci_dma_dev_setup(dev);
> -
> -	/* Read default IRQs and fixup if necessary */
> -	pci_read_irq_line(dev);
> -	if (ppc_md.pci_irq_fixup)
> -		ppc_md.pci_irq_fixup(dev);
>  }
>  
>  int pcibios_add_device(struct pci_dev *dev)
> -- 
> 2.1.0
> 
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