> From: Chatre, Reinette <reinette.chatre@xxxxxxxxx> > Sent: Friday, April 28, 2023 1:36 AM > > Interrupt context is statically allocated at the time interrupts > are allocated. Following allocation, the context is managed by > directly accessing the elements of the array using the vector > as index. The storage is released when interrupts are disabled. > > It is possible to dynamically allocate a single MSI-X interrupt > after MSI-X is enabled. A dynamic storage for interrupt context > is needed to support this. Replace the interrupt context array with an > xarray (similar to what the core uses as store for MSI descriptors) > that can support the dynamic expansion while maintaining the > custom that uses the vector as index. > > With a dynamic storage it is no longer required to pre-allocate > interrupt contexts at the time the interrupts are allocated. > MSI and MSI-X interrupt contexts are only used when interrupts are > enabled. Their allocation can thus be delayed until interrupt enabling. > Only enabled interrupts will have associated interrupt contexts. > Whether an interrupt has been allocated (a Linux irq number exists > for it) becomes the criteria for whether an interrupt can be enabled. > > Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
