mlxbf-bootctl: Support setting the ARM boot state to "OS up"

The BlueField has internal registers to store the ARM boot states.
Support setting the BlueField ARM boot state to "OS up".
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20230809162857.21243-3-asmaa@nvidia.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/mellanox/mlxbf-bootctl.c

@@ -80,6 +80,7 @@ static const char * const mlxbf_rsh_log_level[] = {
 	"INFO", "WARN", "ERR", "ASSERT"};
 
 static DEFINE_MUTEX(icm_ops_lock);
+static DEFINE_MUTEX(os_up_lock);
 
 /* ARM SMC call which is atomic and no need for lock. */
 static int mlxbf_bootctl_smc(unsigned int smc_op, int smc_arg)
@@ -431,6 +432,28 @@ static ssize_t large_icm_store(struct device *dev,
 	return res.a0 ? -EPERM : count;
 }
 
+static ssize_t os_up_store(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct arm_smccc_res res;
+	unsigned long val;
+	int err;
+
+	err = kstrtoul(buf, 10, &val);
+	if (err)
+		return err;
+
+	if (val != 1)
+		return -EINVAL;
+
+	mutex_lock(&os_up_lock);
+	arm_smccc_smc(MLNX_HANDLE_OS_UP, 0, 0, 0, 0, 0, 0, 0, &res);
+	mutex_unlock(&os_up_lock);
+
+	return count;
+}
+
 static DEVICE_ATTR_RW(post_reset_wdog);
 static DEVICE_ATTR_RW(reset_action);
 static DEVICE_ATTR_RW(second_reset_action);
@@ -439,6 +462,7 @@ static DEVICE_ATTR_RO(secure_boot_fuse_state);
 static DEVICE_ATTR_WO(fw_reset);
 static DEVICE_ATTR_WO(rsh_log);
 static DEVICE_ATTR_RW(large_icm);
+static DEVICE_ATTR_WO(os_up);
 
 static struct attribute *mlxbf_bootctl_attrs[] = {
 	&dev_attr_post_reset_wdog.attr,
@@ -449,6 +473,7 @@ static struct attribute *mlxbf_bootctl_attrs[] = {
 	&dev_attr_fw_reset.attr,
 	&dev_attr_rsh_log.attr,
 	&dev_attr_large_icm.attr,
+	&dev_attr_os_up.attr,
 	NULL
 };
 

drivers/platform/mellanox/mlxbf-bootctl.h

@@ -90,6 +90,11 @@
 
 #define MAX_ICM_BUFFER_SIZE 10
 
+/*
+ * SMC function ID to set the ARM boot state to up
+ */
+#define MLNX_HANDLE_OS_UP    0x82000014
+
 /* SMC function IDs for SiP Service queries */
 #define MLXBF_BOOTCTL_SIP_SVC_CALL_COUNT	0x8200ff00
 #define MLXBF_BOOTCTL_SIP_SVC_UID		0x8200ff01