Merging upstream version 4.19.282.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index e8cd66705..5ccbbb3eb 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -705,6 +705,39 @@ static int scmi_remove(struct platform_device *pdev)
 	return ret;
 }
 
+static int scmi_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 inline int
 scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, int prot_id)
 {
@@ -720,6 +753,10 @@ scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev, int prot_id)
 		goto idr_alloc;
 	}
 
+	ret = scmi_mailbox_chan_validate(dev);
+	if (ret)
+		return ret;
+
 	cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL);
 	if (!cinfo)
 		return -ENOMEM;