Merge tag 'v6.8-rc4' into x86/percpu, to resolve conflicts and refresh the branch

[linux-block.git] / arch / x86 / kernel / smp.c

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 96a771f9f930a6aba1b77967169808bce3b3eace..2908e063d7d830db32decbfefbd017fd05292700 100644 (file)
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -148,14 +148,16 @@ static int register_stop_handler(void)
 
 static void native_stop_other_cpus(int wait)
 {
-       unsigned int cpu = smp_processor_id();
+       unsigned int old_cpu, this_cpu;
        unsigned long flags, timeout;
 
        if (reboot_force)
                return;
 
        /* Only proceed if this is the first CPU to reach this code */
-       if (atomic_cmpxchg(&stopping_cpu, -1, cpu) != -1)
+       old_cpu = -1;
+       this_cpu = smp_processor_id();
+       if (!atomic_try_cmpxchg(&stopping_cpu, &old_cpu, this_cpu))
                return;
 
        /* For kexec, ensure that offline CPUs are out of MWAIT and in HLT */
@@ -186,7 +188,7 @@ static void native_stop_other_cpus(int wait)
         * NMIs.
         */
        cpumask_copy(&cpus_stop_mask, cpu_online_mask);
-       cpumask_clear_cpu(cpu, &cpus_stop_mask);
+       cpumask_clear_cpu(this_cpu, &cpus_stop_mask);
 
        if (!cpumask_empty(&cpus_stop_mask)) {
                apic_send_IPI_allbutself(REBOOT_VECTOR);
@@ -210,6 +212,8 @@ static void native_stop_other_cpus(int wait)
                 * CPUs to stop.
                 */
                if (!smp_no_nmi_ipi && !register_stop_handler()) {
+                       unsigned int cpu;
+
                        pr_emerg("Shutting down cpus with NMI\n");
 
                        for_each_cpu(cpu, &cpus_stop_mask)