On 2014/11/12 22:46, Thomas Gleixner wrote:

On Wed, 12 Nov 2014, Marc Zyngier wrote:

quoted

This patch introduces two optionnal fields to the msi_chip structure:
- a pointer to an irq domain, describing the MSI domain associated
  with this msi_chip. To be populated with msi_create_irq_domain.
- a domain_alloc_irqs() callback that has the same purpose as
  arch_setup_msi_irqs(), with the above domain as an additional
  parameter.

If both of these fields are non-NULL, then domain_alloc_irqs() is
called, bypassing the setup_irq callback. This allows the MSI driver
to use the domain stacking feature without mandating core support in
the architecture.

I'd rather have the callback in the irqdomain itself. Along with a
callback to free the interrupts.

AFAICT is msi_chip more or less a wrapper around the actual MSI irq
domain. So we rather move towards assigning irqdomain to the pci bus
and get rid of msi_chip instead of adding another level of obscure
indirection through msi_chip.

Hi Thomas and Marc,

I'm trying to replace all weak functions , such as
arch_setup_msi_irqs()/arch_setup_msi_irq(), in drivers/pci/msi.c.

The framework core changes are almost ready, but it does take time
to convert current arch_setup_msi_irqs() implementations to new
irqdomain interfaces.

Not sure whether it's the right direction to go:(
Regards!
Gerry

Thanks,

	tglx