Re: [PATCH 6/8] Provide interrupt mapping information in PCI config registers.

[Richard Henderson]

On 6/2/21 8:53 PM, Jason Thorpe wrote:
> Use system-specific information to program the interrupt line register
> with the interrupt mappings, which is what the SRM console does on real
> hardware; some operating systems (e.g. NetBSD) use this information
> rather than having interrupt mappings tables for every possible system
> variation.
>
> Signed-off-by: Jason Thorpe <thorpej@me.com>

Thanks.

> +  /* Map the interrupt and program the IRQ into the line register.
> +     Some operating systems rely on the Console providing this information
> +     in order to avoid having mapping tables for every possible system
> +     variation.  */
> +
> +  const uint8_t pin = pci_config_readb(bdf, PCI_INTERRUPT_PIN);
> +  const uint8_t slot = PCI_SLOT(bdf);
> +  const int irq = MAP_PCI_INTERRUPT(slot, pin, class_id);
> +
> +  if (irq == -1)
> +    {
> +      /* No interrupt mapping.  */
> +      pci_config_writeb(bdf, PCI_INTERRUPT_LINE, 0xff);
> +    }
> +  else
> +    {
> +      pci_config_writeb(bdf, PCI_INTERRUPT_LINE, irq);
> +    }

I've folded this non-distinction into the functional interface.

> +#define MAP_PCI_INTERRUPT(SLOT, PIN, CLASS_ID)                 \

I've turned this into a static inline.


r~