iommu/amd: Enable separate interrupt for PPR and GA log

iommu/amd: Enable separate interrupt for PPR and GA log

AMD IOMMU has three log buffers (i.e. Event, PPR, and GA). These logs can
be configured to generate different interrupts when an entry is inserted
into a log buffer.

However, current implementation share single interrupt to handle all three
logs. With increasing usages of the GA (for IOMMU AVIC) and PPR logs (for
IOMMUv2 APIs and SVA), interrupt sharing could potentially become
performance bottleneck.

Hence, separate IOMMU interrupt into use three separate vectors and irq
threads with corresponding name, which will be displayed in the
/proc/interrupts as "AMD-Vi<x>-[Evt/PPR/GA]", where "x" is an IOMMU id.

Note that this patch changes interrupt handling only in IOMMU x2apic mode
(MMIO 0x18[IntCapXTEn]=1). In legacy mode it will continue to use single
MSI interrupt.

Signed-off-by: Vasant Hegde<vasant.hegde@amd.com>
Reviewed-by: Alexey Kardashevskiy<aik@amd.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20230628053222.5962-3-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>