linux-kernel - [PATCH 5/5] firmware: xilinx: Add sysfs and IOCTL to set boot health status

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Message-Id: <1575502159-11327-6-git-send-email-jolly.shah@xilinx.com>
Date:   Wed,  4 Dec 2019 15:29:19 -0800
From:   Jolly Shah <jolly.shah@...inx.com>
To:     ard.biesheuvel@...aro.org, mingo@...nel.org,
        gregkh@...uxfoundation.org, matt@...eblueprint.co.uk,
        sudeep.holla@....com, hkallweit1@...il.com, keescook@...omium.org,
        dmitry.torokhov@...il.com, michal.simek@...inx.com
Cc:     rajanv@...inx.com, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, Rajan Vaja <rajan.vaja@...inx.com>,
        Jolly Shah <jolly.shah@...inx.com>
Subject: [PATCH 5/5] firmware: xilinx: Add sysfs and IOCTL to set boot health status

From: Rajan Vaja <rajan.vaja@...inx.com>

Add sysfs interface to set boot health status from userspace.
Add IOCTL ID used by this interface to communicate with firmware.

If PMUFW is compiled with CHECK_HEALTHY_BOOT, it will check the
healthy bit on FPD WDT expiration. If healthy bit is set by a user
application running in Linux, PMUFW will do APU only restart. If
healthy bit is not set during FPD WDT expiration, PMUFW will do
system restart.

Signed-off-by: Michal Simek <michal.simek@...inx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@...inx.com>
Signed-off-by: Jolly Shah <jolly.shah@...inx.com>
---
 Documentation/ABI/stable/sysfs-firmware-zynqmp | 21 +++++++++++++
 drivers/firmware/xilinx/zynqmp.c               | 42 ++++++++++++++++++++++++++
 include/linux/firmware/xlnx-zynqmp.h           |  2 ++
 3 files changed, 65 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-firmware-zynqmp b/Documentation/ABI/stable/sysfs-firmware-zynqmp
index 13e4fd2..eeae291 100644
--- a/Documentation/ABI/stable/sysfs-firmware-zynqmp
+++ b/Documentation/ABI/stable/sysfs-firmware-zynqmp
@@ -80,3 +80,24 @@ Description:
 		# echo "subsystem" > /sys/firmware/zynqmp/shutdown_scope
 
 Users:		Xilinx
+
+What:		/sys/firmware/zynqmp/health_status
+Date:		April 2018
+KernelVersion:	4.14.0
+Contact:	"Rajan Vaja" <rajanv@...inx.com>
+Description:
+		This sysfs interface allows to set the health status. If PMUFW
+		is compiled with CHECK_HEALTHY_BOOT, it will check the healthy
+		bit on FPD WDT expiration. If healthy bit is set by a user
+		application running in Linux, PMUFW will do APU only restart. If
+		healthy bit is not set during FPD WDT expiration, PMUFW will do
+		system restart.
+
+		Usage:
+		Set healty bit
+		# echo 1 > /sys/firmware/zynqmp/health_status
+
+		Unset healty bit
+		# echo 0 > /sys/firmware/zynqmp/health_status
+
+Users:		Xilinx
diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
index b23bda4..4e497a3 100644
--- a/drivers/firmware/xilinx/zynqmp.c
+++ b/drivers/firmware/xilinx/zynqmp.c
@@ -479,6 +479,7 @@ static inline int zynqmp_is_valid_ioctl(u32 ioctl_id)
 	case IOCTL_READ_GGS:
 	case IOCTL_WRITE_PGGS:
 	case IOCTL_READ_PGGS:
+	case IOCTL_SET_BOOT_HEALTH_STATUS:
 		return 1;
 	default:
 		return 0;
@@ -886,6 +887,46 @@ static struct kobj_attribute zynqmp_attr_shutdown_scope =
 						__ATTR_RW(shutdown_scope);
 
 /**
+ * health_status_store - Store health_status sysfs attribute
+ * @kobj:	Kobject structure
+ * @attr:	Kobject attribute structure
+ * @buf:	User entered health_status attribute string
+ * @count:	Buffer size
+ *
+ * User-space interface for setting the boot health status.
+ * Usage: echo <value> > /sys/firmware/zynqmp/health_status
+ *
+ * Value:
+ *	1 - Set healthy bit to 1
+ *	0 - Unset healthy bit
+ *
+ * Return:	count argument if request succeeds, the corresponding error
+ *		code otherwise
+ */
+static ssize_t health_status_store(struct kobject *kobj,
+				   struct kobj_attribute *attr,
+				   const char *buf, size_t count)
+{
+	int ret;
+	unsigned int value;
+
+	ret = kstrtouint(buf, 10, &value);
+	if (ret)
+		return ret;
+
+	ret = zynqmp_pm_ioctl(0, IOCTL_SET_BOOT_HEALTH_STATUS, value, 0, NULL);
+	if (ret) {
+		pr_err("unable to set healthy bit value to %u\n", value);
+		return ret;
+	}
+
+	return count;
+}
+
+static struct kobj_attribute zynqmp_attr_health_status =
+						__ATTR_WO(health_status);
+
+/**
  * config_reg_store - Write config_reg sysfs attribute
  * @kobj:	Kobject structure
  * @attr:	Kobject attribute structure
@@ -1011,6 +1052,7 @@ static struct kobj_attribute zynqmp_attr_config_reg =
 
 static struct attribute *attrs[] = {
 	&zynqmp_attr_shutdown_scope.attr,
+	&zynqmp_attr_health_status.attr,
 	&zynqmp_attr_config_reg.attr,
 	NULL,
 };
diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
index 54061de..c6f3c50 100644
--- a/include/linux/firmware/xlnx-zynqmp.h
+++ b/include/linux/firmware/xlnx-zynqmp.h
@@ -107,6 +107,8 @@ enum pm_ioctl_id {
 	IOCTL_READ_GGS,
 	IOCTL_WRITE_PGGS,
 	IOCTL_READ_PGGS,
+	/* Set healthy bit value*/
+	IOCTL_SET_BOOT_HEALTH_STATUS = 17,
 };
 
 enum pm_query_id {
-- 
2.7.4