Merge tag 'cxl-fixes-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull cxl fixes from Dan Williams:
 "Two fixups for CXL (Compute Express Link) in presence of passthrough
  decoders.

  This primarily helps developers using the QEMU CXL emulation, but with
  the impending arrival of CXL switches these types of topologies will
  be of interest to end users.

   - Fix a crash when shutting down regions in the presence of
     passthrough decoders

   - Fix region creation to understand passthrough decoders instead of
     the narrower definition of passthrough ports"

* tag 'cxl-fixes-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl/region: Fix passthrough-decoder detection
  cxl/region: Fix null pointer dereference for resetting decoder

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 02f28da519e351..940f805b153408 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -131,7 +131,7 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
 		struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
 		struct cxl_port *iter = cxled_to_port(cxled);
 		struct cxl_ep *ep;
-		int rc;
+		int rc = 0;
 
 		while (!is_cxl_root(to_cxl_port(iter->dev.parent)))
 			iter = to_cxl_port(iter->dev.parent);
@@ -143,7 +143,8 @@ static int cxl_region_decode_reset(struct cxl_region *cxlr, int count)
 
 			cxl_rr = cxl_rr_load(iter, cxlr);
 			cxld = cxl_rr->decoder;
-			rc = cxld->reset(cxld);
+			if (cxld->reset)
+				rc = cxld->reset(cxld);
 			if (rc)
 				return rc;
 		}
@@ -186,7 +187,8 @@ static int cxl_region_decode_commit(struct cxl_region *cxlr)
 			     iter = ep->next, ep = cxl_ep_load(iter, cxlmd)) {
 				cxl_rr = cxl_rr_load(iter, cxlr);
 				cxld = cxl_rr->decoder;
-				cxld->reset(cxld);
+				if (cxld->reset)
+					cxld->reset(cxld);
 			}
 
 			cxled->cxld.reset(&cxled->cxld);
@@ -991,10 +993,10 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 		int i, distance;
 
 		/*
-		 * Passthrough ports impose no distance requirements between
+		 * Passthrough decoders impose no distance requirements between
 		 * peers
 		 */
-		if (port->nr_dports == 1)
+		if (cxl_rr->nr_targets == 1)
 			distance = 0;
 		else
 			distance = p->nr_targets / cxl_rr->nr_targets;