cxl/hdm: Require all decoders to be enumerated

In preparation for region provisioning all device decoders need to be
enumerated since DPA allocations are calculated by summing the
capacities of all decoders in a set. I.e. the programming for decoder[N]
depends on the state of decoder[N-1], so skipping over decoders that
fail to initialize prevents accurate DPA accounting.

Signed-off-by: Ben Widawsky <bwidawsk@kernel.org>
[djbw: reword changelog]
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/165603879664.551046.6863805202478861026.stgit@dwillia2-xfh
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/hdm.c

@@ -199,7 +199,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 {
 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
 	struct cxl_port *port = cxlhdm->port;
-	int i, committed, failed;
+	int i, committed;
 	u32 ctrl;
 
 	/*
@@ -219,7 +219,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 	if (committed != cxlhdm->decoder_count)
 		msleep(20);
 
-	for (i = 0, failed = 0; i < cxlhdm->decoder_count; i++) {
+	for (i = 0; i < cxlhdm->decoder_count; i++) {
 		int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 };
 		int rc, target_count = cxlhdm->target_count;
 		struct cxl_decoder *cxld;
@@ -237,8 +237,7 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 		rc = init_hdm_decoder(port, cxld, target_map, hdm, i);
 		if (rc) {
 			put_device(&cxld->dev);
-			failed++;
-			continue;
+			return rc;
 		}
 		rc = add_hdm_decoder(port, cxld, target_map);
 		if (rc) {
@@ -248,11 +247,6 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
 		}
 	}
 
-	if (failed == cxlhdm->decoder_count) {
-		dev_err(&port->dev, "No valid decoders found\n");
-		return -ENXIO;
-	}
-
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);