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From:   Cristian Marussi <cristian.marussi@arm.com>
To:     linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc:     sudeep.holla@arm.com, james.quinlan@broadcom.com,
        Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com,
        etienne.carriere@linaro.org, vincent.guittot@linaro.org,
        souvik.chakravarty@arm.com, cristian.marussi@arm.com
Subject: [PATCH 02/22] firmware: arm_scmi: Make protocols init fail on basic errors
Date:   Wed, 30 Mar 2022 16:05:31 +0100
Message-Id: <20220330150551.2573938-3-cristian.marussi@arm.com>
In-Reply-To: <20220330150551.2573938-1-cristian.marussi@arm.com>
References: <20220330150551.2573938-1-cristian.marussi@arm.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Bail out of protocol initialization routine early when basic information
about protocol version and attributes could not be retrieved: failing to
act this way can lead to a successfully initialized SCMI protocol which
is in fact not fully functional.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/base.c    |  5 ++++-
 drivers/firmware/arm_scmi/clock.c   |  8 ++++++--
 drivers/firmware/arm_scmi/perf.c    | 10 +++++++---
 drivers/firmware/arm_scmi/power.c   | 10 +++++++---
 drivers/firmware/arm_scmi/reset.c   | 10 +++++++---
 drivers/firmware/arm_scmi/sensors.c |  4 +++-
 drivers/firmware/arm_scmi/system.c  |  5 ++++-
 7 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index f5219334fd3a..ebaef5d320af 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -359,7 +359,10 @@ static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
 	ph->set_priv(ph, rev);
 
-	scmi_base_attributes_get(ph);
+	ret = scmi_base_attributes_get(ph);
+	if (ret)
+		return ret;
+
 	scmi_base_vendor_id_get(ph, false);
 	scmi_base_vendor_id_get(ph, true);
 	scmi_base_implementation_version_get(ph);
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index ef6431c6eb1c..0ae39ee920e9 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -361,7 +361,9 @@ static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 	int clkid, ret;
 	struct clock_info *cinfo;
 
-	ph->xops->version_get(ph, &version);
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
 
 	dev_dbg(ph->dev, "Clock Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
@@ -370,7 +372,9 @@ static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 	if (!cinfo)
 		return -ENOMEM;
 
-	scmi_clock_protocol_attributes_get(ph, cinfo);
+	ret = scmi_clock_protocol_attributes_get(ph, cinfo);
+	if (ret)
+		return ret;
 
 	cinfo->clk = devm_kcalloc(ph->dev, cinfo->num_clocks,
 				  sizeof(*cinfo->clk), GFP_KERNEL);
diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index f4cd5193b961..e9f68b91580c 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -873,11 +873,13 @@ static const struct scmi_protocol_events perf_protocol_events = {
 
 static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph)
 {
-	int domain;
+	int domain, ret;
 	u32 version;
 	struct scmi_perf_info *pinfo;
 
-	ph->xops->version_get(ph, &version);
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
 
 	dev_dbg(ph->dev, "Performance Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
@@ -886,7 +888,9 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph)
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_perf_attributes_get(ph, pinfo);
+	ret = scmi_perf_attributes_get(ph, pinfo);
+	if (ret)
+		return ret;
 
 	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
index ad2ab080f344..0f0b94f0b624 100644
--- a/drivers/firmware/arm_scmi/power.c
+++ b/drivers/firmware/arm_scmi/power.c
@@ -280,11 +280,13 @@ static const struct scmi_protocol_events power_protocol_events = {
 
 static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
 {
-	int domain;
+	int domain, ret;
 	u32 version;
 	struct scmi_power_info *pinfo;
 
-	ph->xops->version_get(ph, &version);
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
 
 	dev_dbg(ph->dev, "Power Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
@@ -293,7 +295,9 @@ static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_power_attributes_get(ph, pinfo);
+	ret = scmi_power_attributes_get(ph, pinfo);
+	if (ret)
+		return ret;
 
 	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index 9bf2478ec6d1..9cdbd133db10 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -293,11 +293,13 @@ static const struct scmi_protocol_events reset_protocol_events = {
 
 static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
 {
-	int domain;
+	int domain, ret;
 	u32 version;
 	struct scmi_reset_info *pinfo;
 
-	ph->xops->version_get(ph, &version);
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
 
 	dev_dbg(ph->dev, "Reset Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
@@ -306,7 +308,9 @@ static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_reset_attributes_get(ph, pinfo);
+	ret = scmi_reset_attributes_get(ph, pinfo);
+	if (ret)
+		return ret;
 
 	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index cdbb287bd8bc..f37ac9824a87 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -966,7 +966,9 @@ static int scmi_sensors_protocol_init(const struct scmi_protocol_handle *ph)
 	int ret;
 	struct sensors_info *sinfo;
 
-	ph->xops->version_get(ph, &version);
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
 
 	dev_dbg(ph->dev, "Sensor Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
diff --git a/drivers/firmware/arm_scmi/system.c b/drivers/firmware/arm_scmi/system.c
index e5175ef73b40..cbfc19f7a463 100644
--- a/drivers/firmware/arm_scmi/system.c
+++ b/drivers/firmware/arm_scmi/system.c
@@ -113,10 +113,13 @@ static const struct scmi_protocol_events system_protocol_events = {
 
 static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 {
+	int ret;
 	u32 version;
 	struct scmi_system_info *pinfo;
 
-	ph->xops->version_get(ph, &version);
+	ret = ph->xops->version_get(ph, &version);
+	if (ret)
+		return ret;
 
 	dev_dbg(ph->dev, "System Power Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
-- 
2.32.0