On Fri, Jan 27, 2023 at 05:59:16PM +0000, Alexandru Elisei wrote:
> From: Nikita Venkatesh <Nikita.Venkatesh@xxxxxxx>
>
> The test uses the following method.
>
> The primary CPU brings up all the secondary CPUs, which are held in a wait
> loop. Once the primary releases the CPUs, each of the secondary CPUs
> proceed to issue CPU_OFF.
>
> The primary CPU then checks for the status of the individual CPU_OFF
> request. There is a chance that some CPUs might return from the CPU_OFF
> function call after the primary CPU has finished the scan. There is no
> foolproof method to handle this, but the test tries its best to
> eliminate these false positives by introducing an extra delay if all the
> CPUs are reported offline after the initial scan.
>
> Signed-off-by: Nikita Venkatesh <Nikita.Venkatesh@xxxxxxx>
> [ Alex E: Skip CPU_OFF test if CPU_ON failed, drop cpu_off_success in
> favour of checking AFFINITY_INFO, commit message tweaking ]
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> ---
>
> Decided to drop Drew's Reviewed-by tag because the changes are not trivial
> from the previous version.
>
> arm/psci.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 75 insertions(+), 5 deletions(-)
>
> diff --git a/arm/psci.c b/arm/psci.c
> index f7238f8e0bbd..7034d8ebe6e1 100644
> --- a/arm/psci.c
> +++ b/arm/psci.c
> @@ -72,8 +72,9 @@ static bool psci_affinity_info_off(void)
> }
>
> static int cpu_on_ret[NR_CPUS];
> -static cpumask_t cpu_on_ready, cpu_on_done;
> +static cpumask_t cpu_on_ready, cpu_on_done, cpu_off_done;
> static volatile int cpu_on_start;
> +static volatile int cpu_off_start;
>
> extern void secondary_entry(void);
> static void cpu_on_do_wake_target(void)
> @@ -171,9 +172,71 @@ static bool psci_cpu_on_test(void)
> return !failed;
> }
>
> -int main(void)
> +static void cpu_off_secondary_entry(void *data)
> +{
> + int cpu = smp_processor_id();
> +
> + while (!cpu_off_start)
> + cpu_relax();
> + cpumask_set_cpu(cpu, &cpu_off_done);
> + cpu_psci_cpu_die();
> +}
> +
> +static bool psci_cpu_off_test(void)
> +{
> + bool failed = false;
> + int i, count, cpu;
> +
> + for_each_present_cpu(cpu) {
> + if (cpu == 0)
> + continue;
> + on_cpu_async(cpu, cpu_off_secondary_entry, NULL);
> + }
> +
> + cpumask_set_cpu(0, &cpu_off_done);
> +
> + cpu_off_start = 1;
> + report_info("waiting for the CPUs to be offlined...");
> + while (!cpumask_full(&cpu_off_done))
> + cpu_relax();
> +
> + /* Allow all the other CPUs to complete the operation */
> + for (i = 0; i < 100; i++) {
> + mdelay(10);
> +
> + count = 0;
> + for_each_present_cpu(cpu) {
> + if (cpu == 0)
> + continue;
> + if (psci_affinity_info(cpus[cpu], 0) != PSCI_0_2_AFFINITY_LEVEL_OFF)
> + count++;
> + }
> + if (count > 0)
> + continue;
This should be
if (count == 0)
break;
otherwise we never leave the loop early.
> + }
> +
> + /* Try to catch CPUs that return from CPU_OFF. */
> + if (count == 0)
> + mdelay(100);
> +
> + for_each_present_cpu(cpu) {
> + if (cpu == 0)
> + continue;
> + if (cpu_idle(cpu)) {
> + report_info("CPU%d failed to be offlined", cpu);
> + if (psci_affinity_info(cpus[cpu], 0) == PSCI_0_2_AFFINITY_LEVEL_OFF)
> + report_info("AFFINITY_INFO incorrectly reports CPU%d as offline", cpu);
> + failed = true;
> + }
> + }
> +
> + return !failed;
> +}
> +
> +int main(int argc, char **argv)
> {
> int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> + bool cpu_on_success = true;
>
> report_prefix_push("psci");
>
> @@ -188,10 +251,17 @@ int main(void)
> report(psci_affinity_info_on(), "affinity-info-on");
> report(psci_affinity_info_off(), "affinity-info-off");
>
> - if (ERRATA(6c7a5dce22b3))
> - report(psci_cpu_on_test(), "cpu-on");
> - else
> + if (ERRATA(6c7a5dce22b3)) {
> + cpu_on_success = psci_cpu_on_test();
> + report(cpu_on_success, "cpu-on");
> + } else {
> report_skip("Skipping unsafe cpu-on test. Set ERRATA_6c7a5dce22b3=y to enable.");
> + }
> +
> + if (!cpu_on_success)
> + report_skip("Skipping cpu-off test because the cpu-on test failed");
We should output "was skipped" when the cpu-on test was skipped, rather
than always reporting "failed". We need two booleans, try_cpu_on_test and
cpu_on_success.
> + else
> + report(psci_cpu_off_test(), "cpu-off");
>
> done:
> #if 0
> --
> 2.39.0
>
Thanks,
drew
