1 files changed, 15 insertions, 112 deletions

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index ccde7489edbd..644032cd680e 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1474,6 +1474,14 @@ static int cxl_region_attach_auto(struct cxl_region *cxlr,
 	return 0;
 }
 
+static int cmp_interleave_pos(const void *a, const void *b)
+{
+	struct cxl_endpoint_decoder *cxled_a = *(typeof(cxled_a) *)a;
+	struct cxl_endpoint_decoder *cxled_b = *(typeof(cxled_b) *)b;
+
+	return cxled_a->pos - cxled_b->pos;
+}
+
 static struct cxl_port *next_port(struct cxl_port *port)
 {
 	if (!port->parent_dport)
@@ -1604,131 +1612,26 @@ static int cxl_calc_interleave_pos(struct cxl_endpoint_decoder *cxled)
 	return pos;
 }
 
-static void find_positions(const struct cxl_switch_decoder *cxlsd,
-			   const struct cxl_port *iter_a,
-			   const struct cxl_port *iter_b, int *a_pos,
-			   int *b_pos)
-{
-	int i;
-
-	for (i = 0, *a_pos = -1, *b_pos = -1; i < cxlsd->nr_targets; i++) {
-		if (cxlsd->target[i] == iter_a->parent_dport)
-			*a_pos = i;
-		else if (cxlsd->target[i] == iter_b->parent_dport)
-			*b_pos = i;
-		if (*a_pos >= 0 && *b_pos >= 0)
-			break;
-	}
-}
-
-static int cmp_decode_pos(const void *a, const void *b)
-{
-	struct cxl_endpoint_decoder *cxled_a = *(typeof(cxled_a) *)a;
-	struct cxl_endpoint_decoder *cxled_b = *(typeof(cxled_b) *)b;
-	struct cxl_memdev *cxlmd_a = cxled_to_memdev(cxled_a);
-	struct cxl_memdev *cxlmd_b = cxled_to_memdev(cxled_b);
-	struct cxl_port *port_a = cxled_to_port(cxled_a);
-	struct cxl_port *port_b = cxled_to_port(cxled_b);
-	struct cxl_port *iter_a, *iter_b, *port = NULL;
-	struct cxl_switch_decoder *cxlsd;
-	struct device *dev;
-	int a_pos, b_pos;
-	unsigned int seq;
-
-	/* Exit early if any prior sorting failed */
-	if (cxled_a->pos < 0 || cxled_b->pos < 0)
-		return 0;
-
-	/*
-	 * Walk up the hierarchy to find a shared port, find the decoder that
-	 * maps the range, compare the relative position of those dport
-	 * mappings.
-	 */
-	for (iter_a = port_a; iter_a; iter_a = next_port(iter_a)) {
-		struct cxl_port *next_a, *next_b;
-
-		next_a = next_port(iter_a);
-		if (!next_a)
-			break;
-
-		for (iter_b = port_b; iter_b; iter_b = next_port(iter_b)) {
-			next_b = next_port(iter_b);
-			if (next_a != next_b)
-				continue;
-			port = next_a;
-			break;
-		}
-
-		if (port)
-			break;
-	}
-
-	if (!port) {
-		dev_err(cxlmd_a->dev.parent,
-			"failed to find shared port with %s\n",
-			dev_name(cxlmd_b->dev.parent));
-		goto err;
-	}
-
-	dev = device_find_child(&port->dev, &cxled_a->cxld.hpa_range,
-				match_switch_decoder_by_range);
-	if (!dev) {
-		struct range *range = &cxled_a->cxld.hpa_range;
-
-		dev_err(port->uport_dev,
-			"failed to find decoder that maps %#llx-%#llx\n",
-			range->start, range->end);
-		goto err;
-	}
-
-	cxlsd = to_cxl_switch_decoder(dev);
-	do {
-		seq = read_seqbegin(&cxlsd->target_lock);
-		find_positions(cxlsd, iter_a, iter_b, &a_pos, &b_pos);
-	} while (read_seqretry(&cxlsd->target_lock, seq));
-
-	put_device(dev);
-
-	if (a_pos < 0 || b_pos < 0) {
-		dev_err(port->uport_dev,
-			"failed to find shared decoder for %s and %s\n",
-			dev_name(cxlmd_a->dev.parent),
-			dev_name(cxlmd_b->dev.parent));
-		goto err;
-	}
-
-	dev_dbg(port->uport_dev, "%s comes %s %s\n",
-		dev_name(cxlmd_a->dev.parent),
-		a_pos - b_pos < 0 ? "before" : "after",
-		dev_name(cxlmd_b->dev.parent));
-
-	return a_pos - b_pos;
-err:
-	cxled_a->pos = -1;
-	return 0;
-}
-
 static int cxl_region_sort_targets(struct cxl_region *cxlr)
 {
 	struct cxl_region_params *p = &cxlr->params;
 	int i, rc = 0;
 
-	sort(p->targets, p->nr_targets, sizeof(p->targets[0]), cmp_decode_pos,
-	     NULL);
-
 	for (i = 0; i < p->nr_targets; i++) {
 		struct cxl_endpoint_decoder *cxled = p->targets[i];
 
+		cxled->pos = cxl_calc_interleave_pos(cxled);
 		/*
-		 * Record that sorting failed, but still continue to restore
-		 * cxled->pos with its ->targets[] position so that follow-on
-		 * code paths can reliably do p->targets[cxled->pos] to
-		 * self-reference their entry.
+		 * Record that sorting failed, but still continue to calc
+		 * cxled->pos so that follow-on code paths can reliably
+		 * do p->targets[cxled->pos] to self-reference their entry.
 		 */
 		if (cxled->pos < 0)
 			rc = -ENXIO;
-		cxled->pos = i;
 	}
+	/* Keep the cxlr target list in interleave position order */
+	sort(p->targets, p->nr_targets, sizeof(p->targets[0]),
+	     cmp_interleave_pos, NULL);
 
 	dev_dbg(&cxlr->dev, "region sort %s\n", rc ? "failed" : "successful");
 	return rc;