[PATCH 12/13] cxl/region: Record host bridge target list

[Ben Widawsky <ben.widawsky@xxxxxxxxx>]

Part of host bridge verification in the CXL Type 3 Memory Device
Software Guide calculates the host bridge interleave target list (6th
step in the flow chart). With host bridge verification already done, it
is trivial to store away the configuration information.

TODO: Needs support for switches (7th step in the flow chart).

Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
---
 drivers/cxl/region.c | 41 +++++++++++++++++++++++++++++++----------
 1 file changed, 31 insertions(+), 10 deletions(-)

diff --git a/drivers/cxl/region.c b/drivers/cxl/region.c
index eafd95419895..3120b65b0bc5 100644
--- a/drivers/cxl/region.c
+++ b/drivers/cxl/region.c
@@ -385,6 +385,7 @@ static bool region_hb_rp_config_valid(struct cxl_region *region,
 	}
 
 	for (i = 0; i < hb_count; i++) {
+		struct cxl_decoder *cxld;
 		int idx, position_mask;
 		struct cxl_dport *rp;
 		struct cxl_port *hb;
@@ -422,10 +423,8 @@ static bool region_hb_rp_config_valid(struct cxl_region *region,
 				if (get_rp(ep) != rp)
 					continue;
 
-				if (port_grouping == -1) {
+				if (port_grouping == -1)
 					port_grouping = idx & position_mask;
-					continue;
-				}
 
 				/*
 				 * Do all devices in the region connected to this CXL
@@ -436,10 +435,32 @@ static bool region_hb_rp_config_valid(struct cxl_region *region,
 							  "One or more devices are not connected to the correct Host Bridge Root Port\n");
 					return false;
 				}
+
+				if (!state_update)
+					continue;
+
+				if (dev_WARN_ONCE(&cxld->dev,
+						  port_grouping >= cxld->nr_targets,
+						  "Invalid port grouping %d/%d\n",
+						  port_grouping, cxld->nr_targets))
+					return false;
+
+				cxld->interleave_ways++;
+				cxld->target[port_grouping] = get_rp(ep);
 			}
 		}
-		if (state_update)
+
+		if (state_update) {
+			/* IG doesn't change across host bridges */
+			cxld->interleave_granularity = region_ig(region);
+
+			cxld->decoder_range = (struct range) {
+				.start = region->res->start,
+				.end = region->res->end
+			};
+
 			list_add_tail(&cxld->region_link, &region->staged_list);
+		}
 	}
 
 	return true;
@@ -464,7 +485,7 @@ static bool rootd_contains(const struct cxl_region *region,
 	return true;
 }
 
-static bool rootd_valid(const struct cxl_region *region,
+static bool rootd_valid(struct cxl_region *region,
 			const struct cxl_decoder *rootd,
 			bool state_update)
 {
@@ -489,20 +510,20 @@ static bool rootd_valid(const struct cxl_region *region,
 }
 
 struct rootd_context {
-	const struct cxl_region *region;
-	struct cxl_port *hbs[CXL_DECODER_MAX_INTERLEAVE];
+	struct cxl_region *region;
+	const struct cxl_port *hbs[CXL_DECODER_MAX_INTERLEAVE];
 	int count;
 };
 
 static int rootd_match(struct device *dev, void *data)
 {
 	struct rootd_context *ctx = (struct rootd_context *)data;
-	const struct cxl_region *region = ctx->region;
+	struct cxl_region *region = ctx->region;
 
 	if (!is_root_decoder(dev))
 		return 0;
 
-	return !!rootd_valid(region, to_cxl_decoder(dev), false);
+	return rootd_valid(region, to_cxl_decoder(dev), false);
 }
 
 /*
@@ -516,7 +537,7 @@ static struct cxl_decoder *find_rootd(const struct cxl_region *region,
 	struct rootd_context ctx;
 	struct device *ret;
 
-	ctx.region = region;
+	ctx.region = (struct cxl_region *)region;
 
 	ret = device_find_child((struct device *)&root->dev, &ctx, rootd_match);
 	if (ret)
-- 
2.34.1