#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/syscore_ops.h>
+#include <linux/reboot.h>
#include <asm/cacheflush.h>
#include <asm/hardware/cache-b15-rac.h>
__b15_rac_enable(enable);
}
+static int b15_rac_reboot_notifier(struct notifier_block *nb,
+ unsigned long action,
+ void *data)
+{
+ /* During kexec, we are not yet migrated on the boot CPU, so we need to
+ * make sure we are SMP safe here. Once the RAC is disabled, flag it as
+ * suspended such that the hotplug notifier returns early.
+ */
+ if (action == SYS_RESTART) {
+ spin_lock(&rac_lock);
+ b15_rac_disable_and_flush();
+ clear_bit(RAC_ENABLED, &b15_rac_flags);
+ set_bit(RAC_SUSPENDED, &b15_rac_flags);
+ spin_unlock(&rac_lock);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block b15_rac_reboot_nb = {
+ .notifier_call = b15_rac_reboot_notifier,
+};
+
#ifdef CONFIG_HOTPLUG_CPU
/* The CPU hotplug case is the most interesting one, we basically need to make
* sure that the RAC is disabled for the entire system prior to having a CPU
/* Running on the dying CPU */
static int b15_rac_dying_cpu(unsigned int cpu)
{
+ /* During kexec/reboot, the RAC is disabled via the reboot notifier
+ * return early here.
+ */
+ if (test_bit(RAC_SUSPENDED, &b15_rac_flags))
+ return 0;
+
spin_lock(&rac_lock);
/* Indicate that we are starting a hotplug procedure */
/* Running on a non-dying CPU */
static int b15_rac_dead_cpu(unsigned int cpu)
{
+ /* During kexec/reboot, the RAC is disabled via the reboot notifier
+ * return early here.
+ */
+ if (test_bit(RAC_SUSPENDED, &b15_rac_flags))
+ return 0;
+
spin_lock(&rac_lock);
/* And enable it */
goto out;
}
+ ret = register_reboot_notifier(&b15_rac_reboot_nb);
+ if (ret) {
+ pr_err("failed to register reboot notifier\n");
+ iounmap(b15_rac_base);
+ goto out;
+ }
+
#ifdef CONFIG_HOTPLUG_CPU
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
"arm/cache-b15-rac:dead",
out_cpu_dead:
cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CACHE_B15_RAC_DYING);
out_unmap:
+ unregister_reboot_notifier(&b15_rac_reboot_nb);
iounmap(b15_rac_base);
out:
of_node_put(dn);