diff options
| -rw-r--r-- | arch/arm/mm/cache-b15-rac.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/mm/cache-b15-rac.c b/arch/arm/mm/cache-b15-rac.c index 9ee1d89cced0..f76988790011 100644 --- a/arch/arm/mm/cache-b15-rac.c +++ b/arch/arm/mm/cache-b15-rac.c @@ -16,6 +16,7 @@ #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> @@ -151,6 +152,29 @@ static void b15_rac_enable(void) __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 @@ -191,6 +215,12 @@ static void b15_rac_enable(void) /* 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 */ @@ -207,6 +237,12 @@ static int b15_rac_dying_cpu(unsigned int cpu) /* 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 */ @@ -272,6 +308,13 @@ static int __init b15_rac_init(void) 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", @@ -308,6 +351,7 @@ static int __init b15_rac_init(void) 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); |