irqchip/gic-v3: Implement FEAT_GICv3_NMI support
The FEAT_GICv3_NMI GIC feature coupled with the CPU FEAT_NMI enables
handling NMI interrupts in HW on aarch64, by adding a superpriority
interrupt to the existing GIC priority scheme.
Implement GIC driver support for the FEAT_GICv3_NMI feature.
Rename gic_supports_nmi() helper function to gic_supports_pseudo_nmis()
to make the pseudo NMIs code path clearer and more explicit.
Check, through the ARM64 capabilitity infrastructure, if support
for FEAT_NMI was detected on the core and the system has not overridden
the detection and forced pseudo-NMIs enablement.
If FEAT_NMI is detected, it was not overridden (check embedded in the
system_uses_nmi() call) and the GIC supports the FEAT_GICv3_NMI feature,
install an NMI handler and initialize NMIs related HW GIC registers.
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
2 files changed
