arm64: Create a TLBI invalidate for the kernel

[andrew]

Summary

Add pmap_s1_invalidate_all_kernel to remove the need to check for the
kernel_pmap when it's passed in.

While here replace pmap calls to cpu_tlb_flushID with
pmap_s1_invalidate_all_kernel as they are identical.

Sponsored by: Arm Ltd

[alc]

sys/arm64/arm64/pmap.c

7979

Because kernel_pmap is a constant, not a variable, the code generated for pmap_s1_invalidate_all(kernel_pmap) is already the same as the newly proposed pmap_s1_invalidate_all_kernel(). In short, I don't see a compelling need for this new function.

[andrew]

sys/arm64/arm64/pmap.c

7979

I'm trying to centralise tlb handling to minimise where we need to implement workarounds.

The only remaining caller of pmap_invalidate_all is pmap_remove_pages & that can't take the kernel pamp. We could replace the kernel check in pmap_s1_invalidate_all with a KASSERT in a later change.