3 files changed, 114 insertions, 18 deletions

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 23b9ff920d7e..bea9cf31a12d 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1028,7 +1028,7 @@ static int cxl_mem_get_partition_info(struct cxl_dev_state *cxlds)
  * cxl_dev_state_identify() - Send the IDENTIFY command to the device.
  * @cxlds: The device data for the operation
  *
- * Return: 0 if identify was executed successfully.
+ * Return: 0 if identify was executed successfully or media not ready.
  *
  * This will dispatch the identify command to the device and on success populate
  * structures to be exported to sysfs.
@@ -1041,6 +1041,9 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
 	u32 val;
 	int rc;
 
+	if (!cxlds->media_ready)
+		return 0;
+
 	mbox_cmd = (struct cxl_mbox_cmd) {
 		.opcode = CXL_MBOX_OP_IDENTIFY,
 		.size_out = sizeof(id),
@@ -1102,6 +1105,13 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
 	struct device *dev = cxlds->dev;
 	int rc;
 
+	if (!cxlds->media_ready) {
+		cxlds->dpa_res = DEFINE_RES_MEM(0, 0);
+		cxlds->ram_res = DEFINE_RES_MEM(0, 0);
+		cxlds->pmem_res = DEFINE_RES_MEM(0, 0);
+		return 0;
+	}
+
 	cxlds->dpa_res =
 		(struct resource)DEFINE_RES_MEM(0, cxlds->total_bytes);
 
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index bdbd907884ce..67f4ab6daa34 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -101,23 +101,57 @@ int devm_cxl_port_enumerate_dports(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_port_enumerate_dports, CXL);
 
-/*
- * Wait up to @media_ready_timeout for the device to report memory
- * active.
- */
-int cxl_await_media_ready(struct cxl_dev_state *cxlds)
+static int cxl_dvsec_mem_range_valid(struct cxl_dev_state *cxlds, int id)
+{
+	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+	int d = cxlds->cxl_dvsec;
+	bool valid = false;
+	int rc, i;
+	u32 temp;
+
+	if (id > CXL_DVSEC_RANGE_MAX)
+		return -EINVAL;
+
+	/* Check MEM INFO VALID bit first, give up after 1s */
+	i = 1;
+	do {
+		rc = pci_read_config_dword(pdev,
+					   d + CXL_DVSEC_RANGE_SIZE_LOW(id),
+					   &temp);
+		if (rc)
+			return rc;
+
+		valid = FIELD_GET(CXL_DVSEC_MEM_INFO_VALID, temp);
+		if (valid)
+			break;
+		msleep(1000);
+	} while (i--);
+
+	if (!valid) {
+		dev_err(&pdev->dev,
+			"Timeout awaiting memory range %d valid after 1s.\n",
+			id);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int cxl_dvsec_mem_range_active(struct cxl_dev_state *cxlds, int id)
 {
 	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
 	int d = cxlds->cxl_dvsec;
 	bool active = false;
-	u64 md_status;
 	int rc, i;
+	u32 temp;
 
-	for (i = media_ready_timeout; i; i--) {
-		u32 temp;
+	if (id > CXL_DVSEC_RANGE_MAX)
+		return -EINVAL;
 
+	/* Check MEM ACTIVE bit, up to 60s timeout by default */
+	for (i = media_ready_timeout; i; i--) {
 		rc = pci_read_config_dword(
-			pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(0), &temp);
+			pdev, d + CXL_DVSEC_RANGE_SIZE_LOW(id), &temp);
 		if (rc)
 			return rc;
 
@@ -134,6 +168,39 @@ int cxl_await_media_ready(struct cxl_dev_state *cxlds)
 		return -ETIMEDOUT;
 	}
 
+	return 0;
+}
+
+/*
+ * Wait up to @media_ready_timeout for the device to report memory
+ * active.
+ */
+int cxl_await_media_ready(struct cxl_dev_state *cxlds)
+{
+	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
+	int d = cxlds->cxl_dvsec;
+	int rc, i, hdm_count;
+	u64 md_status;
+	u16 cap;
+
+	rc = pci_read_config_word(pdev,
+				  d + CXL_DVSEC_CAP_OFFSET, &cap);
+	if (rc)
+		return rc;
+
+	hdm_count = FIELD_GET(CXL_DVSEC_HDM_COUNT_MASK, cap);
+	for (i = 0; i < hdm_count; i++) {
+		rc = cxl_dvsec_mem_range_valid(cxlds, i);
+		if (rc)
+			return rc;
+	}
+
+	for (i = 0; i < hdm_count; i++) {
+		rc = cxl_dvsec_mem_range_active(cxlds, i);
+		if (rc)
+			return rc;
+	}
+
 	md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
 	if (!CXLMDEV_READY(md_status))
 		return -EIO;
@@ -241,17 +308,36 @@ static void disable_hdm(void *_cxlhdm)
 	       hdm + CXL_HDM_DECODER_CTRL_OFFSET);
 }
 
-static int devm_cxl_enable_hdm(struct device *host, struct cxl_hdm *cxlhdm)
+int devm_cxl_enable_hdm(struct cxl_port *port, struct cxl_hdm *cxlhdm)
 {
-	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
+	void __iomem *hdm;
 	u32 global_ctrl;
 
+	/*
+	 * If the hdm capability was not mapped there is nothing to enable and
+	 * the caller is responsible for what happens next.  For example,
+	 * emulate a passthrough decoder.
+	 */
+	if (IS_ERR(cxlhdm))
+		return 0;
+
+	hdm = cxlhdm->regs.hdm_decoder;
 	global_ctrl = readl(hdm + CXL_HDM_DECODER_CTRL_OFFSET);
+
+	/*
+	 * If the HDM decoder capability was enabled on entry, skip
+	 * registering disable_hdm() since this decode capability may be
+	 * owned by platform firmware.
+	 */
+	if (global_ctrl & CXL_HDM_DECODER_ENABLE)
+		return 0;
+
 	writel(global_ctrl | CXL_HDM_DECODER_ENABLE,
 	       hdm + CXL_HDM_DECODER_CTRL_OFFSET);
 
-	return devm_add_action_or_reset(host, disable_hdm, cxlhdm);
+	return devm_add_action_or_reset(&port->dev, disable_hdm, cxlhdm);
 }
+EXPORT_SYMBOL_NS_GPL(devm_cxl_enable_hdm, CXL);
 
 int cxl_dvsec_rr_decode(struct device *dev, int d,
 			struct cxl_endpoint_dvsec_info *info)
@@ -425,7 +511,7 @@ int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,
 	if (info->mem_enabled)
 		return 0;
 
-	rc = devm_cxl_enable_hdm(&port->dev, cxlhdm);
+	rc = devm_cxl_enable_hdm(port, cxlhdm);
 	if (rc)
 		return rc;
 
@@ -571,6 +657,7 @@ void read_cdat_data(struct cxl_port *port)
 		/* Don't leave table data allocated on error */
 		devm_kfree(dev, cdat_table);
 		dev_err(dev, "CDAT data read error\n");
+		return;
 	}
 
 	port->cdat.table = cdat_table + sizeof(__le32);
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index da2068475fa2..e7c284c890bc 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -750,11 +750,10 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
 
 	parent_port = parent_dport ? parent_dport->port : NULL;
 	if (IS_ERR(port)) {
-		dev_dbg(uport, "Failed to add %s%s%s%s: %ld\n",
-			dev_name(&port->dev),
-			parent_port ? " to " : "",
+		dev_dbg(uport, "Failed to add%s%s%s: %ld\n",
+			parent_port ? " port to " : "",
 			parent_port ? dev_name(&parent_port->dev) : "",
-			parent_port ? "" : " (root port)",
+			parent_port ? "" : " root port",
 			PTR_ERR(port));
 	} else {
 		dev_dbg(uport, "%s added%s%s%s\n",