On Tue, 16 Nov 2021 14:40:22 +0100, Cédric Le Goater wrote:

Commit 4f86a06e2d6e ("irqdomain: Make normal and nomap irqdomains
exclusive") introduced an IRQ_DOMAIN_FLAG_NO_MAP flag to isolate the
'nomap' domains still in use under the powerpc arch. With this new
flag, the revmap_tree of the IRQ domain is not used anymore. This
change broke the support of shared LSIs [1] in the XIVE driver because
it was relying on a lookup in the revmap_tree to query previously
mapped interrupts. Linux now creates two distinct IRQ mappings on the
same HW IRQ which can lead to unexpected behavior in the drivers.

[...]

Applied to powerpc/fixes.

[1/1] powerpc/xive: Change IRQ domain to a tree domain
      https://git.kernel.org/powerpc/c/8e80a73fa9a7747e3e8255cb149c543aabf65a24

cheers