[PATCH 2/5] drivers: firmware: psci: Register with kernel restart handler

[Lee Jones <lee.jones@xxxxxxxxxx>]

From: Guenter Roeck <linux@xxxxxxxxxxxx>

Register with kernel restart handler instead of setting arm_pm_restart
directly. This enables support for replacing the PSCI restart handler
with a different handler if necessary for a specific board.

Select a priority of 129 to indicate a higher than default priority, but
keep it as low as possible since PSCI reset is known to fail on some
boards.

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Tested-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
 drivers/firmware/psci/psci.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index 3c1c5daf6df2e..18a47c9d5b02b 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -296,7 +296,8 @@ static int get_set_conduit_method(struct device_node *np)
        return 0;
 }
 
-static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
+static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
+                         void *data)
 {
        if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
            psci_system_reset2_supported) {
@@ -309,8 +310,15 @@ static void psci_sys_reset(enum reboot_mode reboot_mode, 
const char *cmd)
        } else {
                invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
        }
+
+       return NOTIFY_DONE;
 }
 
+static struct notifier_block psci_sys_reset_nb = {
+       .notifier_call = psci_sys_reset,
+       .priority = 129,
+};
+
 static void psci_sys_poweroff(void)
 {
        invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
@@ -472,7 +480,7 @@ static void __init psci_0_2_set_functions(void)
                .migrate_info_type = psci_migrate_info_type,
        };
 
-       arm_pm_restart = psci_sys_reset;
+       register_restart_handler(&psci_sys_reset_nb);
 
        pm_power_off = psci_sys_poweroff;
 }
-- 
2.31.1