cxl/region: Calculate peer distance only for reused targets

cxl_switch_port_setup_targets() calculates peer distance before
searching the existing targets. When the endpoint needs a new target,
the calculated distance is never used.

Move cxl_port_peer_distance() into the matching-target branch,
immediately before check_last_peer(). This avoids unnecessary ancestor
walks and per-port region lookups when adding distinct targets.

With cxl_test, the x8 region in cxl-region-sysfs.sh reduces calls to
cxl_port_peer_distance() from 10 to 4, and the x2 auto region from 2
to 1. A misordered-endpoint test confirms that peer validation still
rejects mismatched peers.

Signed-off-by: Richard Cheng <icheng@nvidia.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Link: https://patch.msgid.link/e05b15fed21af3fb7ec2f663ee254df61c06d0e3.1793649898.git.alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

0 files changed, 0 insertions, 0 deletions