gpu: nova-core: add an interrupt delivery self-test

A GPU interrupt can be lost in the MSI or MSI-X allocation, in the GIN
tree's enables, or in the rearm, and every one of those failures looks
the same: no interrupt arrives, and no register or log line says which
one broke.

Add a probe-time self-test, built under NOVA_CORE_SELFTESTS, that
latches the CPU doorbell vector through the GIN software trigger and
waits for a registered handler to service it. One delivery would pass
with a broken rearm, because the first message-signaled interrupt
arrives whether or not the driver rearms, so the test triggers twice and
waits for the first handler to finish before the second trigger. It runs
after GFW boot and before GSP boot, on a quiesced tree, and fails probe
unless both deliveries arrive, each finds only the doorbell pending, and
the leaf ends clear.

The doorbell has the same vector on every supported GPU, so the test
names it without asking GSP-RM. It allocates the PCI vectors for the
doorbell's subtree and releases them before returning, so under MSI-X
the delivery also exercises that subtree's table entry.

Assisted-by: LLM
Co-developed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260930034148.590687-9-jhubbard@nvidia.com
[acourbot: move relevant bits of previous patch into this one.]
[acourbot: remove reference to self-test section of documentation.]
[acourbot: replace completions with atomic polling code.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

0 files changed, 0 insertions, 0 deletions