feat(cco): honor reqs.sdmaQueueCount, clamp to HW max, guard out-of-range queueId

[jhchouuu]

Motivation

ccoDevCommRequirements.sdmaQueueCount was declared but never consumed. The
SDMA channel count could only be set via MORI_SDMA_NUM_CHANNELS, because the
queues were materialized in ccoCommCreate — before reqs is available — and
ccoDevCommCreate merely copied comm->sdmaNumQueue. Setting
reqs.sdmaQueueCount had no effect.

Additionally, thread-scope put/commit/quietQueue did no bounds check on
queueId, so a queueId >= sdmaNumQueue was undefined behavior (wrong-queue
use or an out-of-bounds handle/signal access).

Changes

• Wire reqs.sdmaQueueCount. SDMA queue setup is deferred to
  ccoDevCommCreate, where reqs is known. ccoSdmaSetupCommQueues resolves
  the count from reqs.sdmaQueueCount (0 = env default) and is idempotent per
  comm (the first DevComm fixes the count; later ones reuse the handles).
• EnsureSdmaTransport(int requestedChannels = 0) connects with the
  requested count (0 = MORI_SDMA_NUM_CHANNELS) and exposes the count actually
  connected via SdmaChannels(); CCO adopts it so device-side indexing stays in
  bounds. SHMEM's existing no-arg call is unchanged (defaults to env).
• Clamp instead of abort. Requests above the CDNA per-pair hardware max
  (kMaxSdmaChannelsPerPair = 8, i.e. 4 queues/engine × 2 engines) are clamped
  with a warning rather than failing in hsaKmtCreateQueueExt.
• Guard out-of-range queueId in thread-scope put/commit/quietQueue:
  now a safe no-op. warp/block scope already clamp via the lane/thread → queue
  mapping.

Test Plan

Validated on MI355X (gfx950, 2 GPU, own build) with a 2-rank harness that sets
reqs.sdmaQueueCount directly and probes devComm.sdma.sdmaNumQueue:

• reqs.sdmaQueueCount = 8 → 8 distinct queues; put+quiet PASS.
• = 0, env unset → default 2; PASS.
• = 0, MORI_SDMA_NUM_CHANNELS=4 → 4; PASS.
• = 16 → clamped to 8 (warn, no crash); PASS.
• out-of-range queueId (n+3) → recv untouched, kernel returns (no hang/fault).
• Default path (no sdmaQueueCount) unchanged.
• mori_cco and mori_shmem both build with the new EnsureSdmaTransport
  signature.

🤖 Generated with Claude Code