x86/tboot: Convert to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Gang Wei <gang.wei@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ning Sun <ning.sun@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard L Maliszewski <richard.l.maliszewski@intel.com>
Cc: Shane Wang <shane.wang@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Cc: tboot-devel@lists.sourceforge.net
Link: http://lkml.kernel.org/r/20160713153337.400227322@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 9b0185fbe3eb44029040c05beea605126baa8644..654f6c66fe45b2426c0e2a74a50e478c135eb216 100644 (file)
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -323,25 +323,16 @@ static int tboot_wait_for_aps(int num_aps)
        return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps);
 }
 
-static int tboot_cpu_callback(struct notifier_block *nfb, unsigned long action,
-                             void *hcpu)
+static int tboot_dying_cpu(unsigned int cpu)
 {
-       switch (action) {
-       case CPU_DYING:
-               atomic_inc(&ap_wfs_count);
-               if (num_online_cpus() == 1)
-                       if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
-                               return NOTIFY_BAD;
-               break;
+       atomic_inc(&ap_wfs_count);
+       if (num_online_cpus() == 1) {
+               if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
+                       return -EBUSY;
        }
-       return NOTIFY_OK;
+       return 0;
 }
 
-static struct notifier_block tboot_cpu_notifier =
-{
-       .notifier_call = tboot_cpu_callback,
-};
-
 #ifdef CONFIG_DEBUG_FS
 
 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \
@@ -417,8 +408,8 @@ static __init int tboot_late_init(void)
        tboot_create_trampoline();
 
        atomic_set(&ap_wfs_count, 0);
-       register_hotcpu_notifier(&tboot_cpu_notifier);
-
+       cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "AP_X86_TBOOT_DYING", NULL,
+                         tboot_dying_cpu);
 #ifdef CONFIG_DEBUG_FS
        debugfs_create_file("tboot_log", S_IRUSR,
                        arch_debugfs_dir, NULL, &tboot_log_fops);

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index c5b96d0b6fbf0d4d45184fc1d03da1a54068c25e..070cc7f2886220b5c2820fc210d2cc9af6f9de00 100644 (file)
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -53,6 +53,7 @@ enum cpuhp_state {
        CPUHP_AP_ARM_CORESIGHT4_STARTING,
        CPUHP_AP_ARM64_ISNDEP_STARTING,
        CPUHP_AP_LEDTRIG_STARTING,
+       CPUHP_AP_X86_TBOOT_DYING,
        CPUHP_AP_NOTIFY_STARTING,
        CPUHP_AP_ONLINE,
        CPUHP_TEARDOWN_CPU,