From 507cd4d2c5eb2d647d27b1047e1a8c73c4890cf3 Mon Sep 17 00:00:00 2001
From: Sudeep Holla <sudeep.holla@arm.com>
Date: Wed, 2 Jun 2021 08:38:51 +0100
Subject: [PATCH] firmware: arm_scmi: Add compatibility checks for shmem node
The shared memory node used for communication between the firmware and
the OS should be compatible with "arm,scmi-shmem". Add the check for the
same while parsing the node before fetching the memory regions.
Link: https://lore.kernel.org/r/20210602073851.1005607-2-sudeep.holla@arm.com
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jim Quinlan <jim2101024@gmail.com>
Cc: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
drivers/firmware/arm_scmi/mailbox.c | 3 +++
drivers/firmware/arm_scmi/smc.c | 3 +++
2 files changed, 6 insertions(+)
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
index 4626404be541..e3dcb58314ae 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -69,6 +69,9 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
return -ENOMEM;
shmem = of_parse_phandle(cdev->of_node, "shmem", idx);
+ if (!of_device_is_compatible(shmem, "arm,scmi-shmem"))
+ return -ENXIO;
+
ret = of_address_to_resource(shmem, 0, &res);
of_node_put(shmem);
if (ret) {
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index fcbe2677f84b..bed5596c7209 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -76,6 +76,9 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
return -ENOMEM;
np = of_parse_phandle(cdev->of_node, "shmem", 0);
+ if (!of_device_is_compatible(np, "arm,scmi-shmem"))
+ return -ENXIO;
+
ret = of_address_to_resource(np, 0, &res);
of_node_put(np);
if (ret) {
--
2.30.9