3 files changed, 39 insertions, 0 deletions
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 47e3af440b3d..c2cff5783fda 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -226,6 +226,16 @@ static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
 	cxled->dpa_res = res;
 	cxled->skip = skipped;
 
+	if (resource_contains(&cxlds->pmem_res, res))
+		cxled->mode = CXL_DECODER_PMEM;
+	else if (resource_contains(&cxlds->ram_res, res))
+		cxled->mode = CXL_DECODER_RAM;
+	else {
+		dev_dbg(dev, "decoder%d.%d: %pr mixed\n", port->id,
+			cxled->cxld.id, cxled->dpa_res);
+		cxled->mode = CXL_DECODER_MIXED;
+	}
+
 	return 0;
 }
 
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 2cfa870428c2..9a312f2e2d35 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -172,6 +172,25 @@ static ssize_t target_list_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(target_list);
 
+static ssize_t mode_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct cxl_endpoint_decoder *cxled = to_cxl_endpoint_decoder(dev);
+
+	switch (cxled->mode) {
+	case CXL_DECODER_RAM:
+		return sysfs_emit(buf, "ram\n");
+	case CXL_DECODER_PMEM:
+		return sysfs_emit(buf, "pmem\n");
+	case CXL_DECODER_NONE:
+		return sysfs_emit(buf, "none\n");
+	case CXL_DECODER_MIXED:
+	default:
+		return sysfs_emit(buf, "mixed\n");
+	}
+}
+static DEVICE_ATTR_RO(mode);
+
 static struct attribute *cxl_decoder_base_attrs[] = {
 	&dev_attr_start.attr,
 	&dev_attr_size.attr,
@@ -222,6 +241,7 @@ static const struct attribute_group *cxl_decoder_switch_attribute_groups[] = {
 
 static struct attribute *cxl_decoder_endpoint_attrs[] = {
 	&dev_attr_target_type.attr,
+	&dev_attr_mode.attr,
 	NULL,
 };
 
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 5fe8b59a0b18..afaa76f065f9 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -241,16 +241,25 @@ struct cxl_decoder {
 	unsigned long flags;
 };
 
+enum cxl_decoder_mode {
+	CXL_DECODER_NONE,
+	CXL_DECODER_RAM,
+	CXL_DECODER_PMEM,
+	CXL_DECODER_MIXED,
+};
+
 /**
  * struct cxl_endpoint_decoder - Endpoint  / SPA to DPA decoder
  * @cxld: base cxl_decoder_object
  * @dpa_res: actively claimed DPA span of this decoder
  * @skip: offset into @dpa_res where @cxld.hpa_range maps
+ * @mode: which memory type / access-mode-partition this decoder targets
  */
 struct cxl_endpoint_decoder {
 	struct cxl_decoder cxld;
 	struct resource *dpa_res;
 	resource_size_t skip;
+	enum cxl_decoder_mode mode;
 };
 
 /**