platform-msi: Allow creation of a MSI-based stacked irq domain
We almost have all the needed bits requiredable to create a irq domain
on top of a MSI domain.
For this, we enable a few things:
- the virq is stored in the msi_desc
- device, msi_alloc_info and domain-specific data
are stored in the platform_priv_data structure
- we introduce a new API for platform-msi:
/* Allocate MSIs in an MSI domain */
int platform_msi_domain_alloc(struct irq_domain *domain,
unsigned int virq,
unsigned int nr_irqs);
/* Free MSIs from an MSI domain */
void platform_msi_domain_free(struct irq_domain *domain,
unsigned int virq,
unsigned int nvec);
/* Obtain the host data passed to platform_msi_create_device_domain */
void *platform_msi_get_host_data(struct irq_domain *domain);
platform_msi_create_device_domain() is a hybrid of irqdomain creation
and interrupt allocation, creating a domain backed by the MSIs associated
to a device. IRQs can then be allocated in that domain using
platform_msi_domain_alloc().
This now allows a wired irq to MSI bridge to be created.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>