3 files changed, 45 insertions, 9 deletions

diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 73140b854b31..c15928b8c5cc 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -14,7 +14,6 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/device.h>
-#include <linux/of.h>
 
 #include "common.h"
 
@@ -436,7 +435,7 @@ struct scmi_device *scmi_device_create(struct device_node *np,
 	/* Nothing to do. */
 	if (!phead) {
 		mutex_unlock(&scmi_requested_devices_mtx);
-		return scmi_dev;
+		return NULL;
 	}
 
 	/* Walk the list of requested devices for protocol and create them */
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index d21c7eafd641..dbc474ff62b7 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2221,8 +2221,8 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo,
 	hash_init(info->pending_xfers);
 
 	/* Allocate a bitmask sized to hold MSG_TOKEN_MAX tokens */
-	info->xfer_alloc_table = devm_kcalloc(dev, BITS_TO_LONGS(MSG_TOKEN_MAX),
-					      sizeof(long), GFP_KERNEL);
+	info->xfer_alloc_table = devm_bitmap_zalloc(dev, MSG_TOKEN_MAX,
+						    GFP_KERNEL);
 	if (!info->xfer_alloc_table)
 		return -ENOMEM;
 
@@ -2657,6 +2657,7 @@ static int scmi_probe(struct platform_device *pdev)
 	struct scmi_handle *handle;
 	const struct scmi_desc *desc;
 	struct scmi_info *info;
+	bool coex = IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX);
 	struct device *dev = &pdev->dev;
 	struct device_node *child, *np = dev->of_node;
 
@@ -2731,16 +2732,13 @@ static int scmi_probe(struct platform_device *pdev)
 			dev_warn(dev, "Failed to setup SCMI debugfs.\n");
 
 		if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
-			bool coex =
-			      IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX);
-
 			ret = scmi_debugfs_raw_mode_setup(info);
 			if (!coex) {
 				if (ret)
 					goto clear_dev_req_notifier;
 
-				/* Bail out anyway when coex enabled */
-				return ret;
+				/* Bail out anyway when coex disabled. */
+				return 0;
 			}
 
 			/* Coex enabled, carry on in any case. */
@@ -2764,6 +2762,8 @@ static int scmi_probe(struct platform_device *pdev)
 	ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE);
 	if (ret) {
 		dev_err(dev, "unable to communicate with SCMI\n");
+		if (coex)
+			return 0;
 		goto notification_exit;
 	}
 
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
index 0d9c9538b7f4..112c285deb97 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -52,6 +52,39 @@ static bool mailbox_chan_available(struct device_node *of_node, int idx)
 					   "#mbox-cells", idx, NULL);
 }
 
+static int mailbox_chan_validate(struct device *cdev)
+{
+	int num_mb, num_sh, ret = 0;
+	struct device_node *np = cdev->of_node;
+
+	num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+	num_sh = of_count_phandle_with_args(np, "shmem", NULL);
+	/* Bail out if mboxes and shmem descriptors are inconsistent */
+	if (num_mb <= 0 || num_sh > 2 || num_mb != num_sh) {
+		dev_warn(cdev, "Invalid channel descriptor for '%s'\n",
+			 of_node_full_name(np));
+		return -EINVAL;
+	}
+
+	if (num_sh > 1) {
+		struct device_node *np_tx, *np_rx;
+
+		np_tx = of_parse_phandle(np, "shmem", 0);
+		np_rx = of_parse_phandle(np, "shmem", 1);
+		/* SCMI Tx and Rx shared mem areas have to be distinct */
+		if (!np_tx || !np_rx || np_tx == np_rx) {
+			dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",
+				 of_node_full_name(np));
+			ret = -EINVAL;
+		}
+
+		of_node_put(np_tx);
+		of_node_put(np_rx);
+	}
+
+	return ret;
+}
+
 static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 			      bool tx)
 {
@@ -64,6 +97,10 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 	resource_size_t size;
 	struct resource res;
 
+	ret = mailbox_chan_validate(cdev);
+	if (ret)
+		return ret;
+
 	smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
 	if (!smbox)
 		return -ENOMEM;