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

Jolly Shah
2019-12-04T23:29:50Z

From: Rajan Vaja <rajan.vaja@xilinx.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@xilinx.com>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jolly.shah@xilinx.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@xilinx.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