===================================================================
@@ -46,7 +46,8 @@
/* This keeps a track of which one is the crashing cpu. */
int crashing_cpu = -1;
-static cpumask_t cpus_in_crash = CPU_MASK_NONE;
+static atomic_t cpus_in_crash;
+static int time_to_dump;
#define CRASH_HANDLER_MAX 3
/* NULL terminated list of shutdown handles */
@@ -67,21 +68,27 @@ static int handle_fault(struct pt_regs *
void crash_ipi_callback(struct pt_regs *regs)
{
+ static cpumask_t cpus_state_saved = CPU_MASK_NONE;
+
int cpu = smp_processor_id();
if (!cpu_online(cpu))
return;
hard_irq_disable();
- if (!cpumask_test_cpu(cpu, &cpus_in_crash))
+ if (!cpumask_test_cpu(cpu, &cpus_state_saved)) {
crash_save_cpu(regs, cpu);
- cpumask_set_cpu(cpu, &cpus_in_crash);
+ cpumask_set_cpu(cpu, &cpus_state_saved);
+ }
+
+ atomic_inc(&cpus_in_crash);
+ smp_mb__after_atomic_inc();
/*
* Starting the kdump boot.
* This barrier is needed to make sure that all CPUs are stopped.
*/
- while (!cpumask_test_cpu(crashing_cpu, &cpus_in_crash))
+ while (!time_to_dump)
cpu_relax();
if (ppc_md.kexec_cpu_down)
@@ -115,19 +122,18 @@ again:
* respond.
*/
msecs = IPI_TIMEOUT;
- while ((cpumask_weight(&cpus_in_crash) < ncpus) && (--msecs > 0)) {
+ while ((atomic_read(&cpus_in_crash) < ncpus) && (--msecs > 0))
mdelay(1);
- }
/* Would it be better to replace the trap vector here? */
- if (cpumask_weight(&cpus_in_crash) >= ncpus) {
+ if (atomic_read(&cpus_in_crash) >= ncpus) {
printk(KERN_EMERG "IPI complete\n");
return;
}
printk(KERN_EMERG "ERROR: %d cpu(s) not responding\n",
- ncpus - cpumask_weight(&cpus_in_crash));
+ ncpus - atomic_read(&cpus_in_crash));
/*
* If we have a panic timeout set then we can't wait indefinitely
@@ -155,10 +161,10 @@ again:
* crash code again. We need to reset cpus_in_crash so we
* wait for everyone to do this.
*/
- cpus_in_crash = CPU_MASK_NONE;
+ atomic_set(&cpus_in_crash, 0);
smp_mb();
- while (cpumask_weight(&cpus_in_crash) < ncpus)
+ while (atomic_read(&cpus_in_crash) < ncpus)
cpu_relax();
}
@@ -316,7 +322,6 @@ void default_machine_crash_shutdown(stru
* such that another IPI will not be sent.
*/
crashing_cpu = smp_processor_id();
- crash_save_cpu(regs, crashing_cpu);
/*
* If we came in via system reset, wait a while for the secondary
@@ -326,7 +331,11 @@ void default_machine_crash_shutdown(stru
mdelay(PRIMARY_TIMEOUT);
crash_kexec_prepare_cpus(crashing_cpu);
- cpumask_set_cpu(crashing_cpu, &cpus_in_crash);
+
+ crash_save_cpu(regs, crashing_cpu);
+
+ time_to_dump = 1;
+
crash_kexec_wait_realmode(crashing_cpu);
machine_kexec_mask_interrupts();
We might enter the secondary CPU capture code twice, eg if we have to unstick some CPUs with a system reset. In this case we don't want to overwrite the state on CPUs that had made it into the capture code OK, so use the cpus_state_saved cpumask for that and make it local to crash_ipi_callback. For controlling progress now use atomic_t cpus_in_crash to count how many CPUs have made it into the kdump code, and time_to_dump to tell everyone it's time to dump. Signed-off-by: Anton Blanchard <anton@samba.org> ---