On Wed, Nov 06, 2024 at 12:38:18PM +0100, Andrew Jones wrote:
> We should ensure that when hart_mask has more than one hartid
> that both harts get IPIs with a single call of the IPI function.
>
> Signed-off-by: Andrew Jones <andrew.jones@xxxxxxxxx>
> ---
> riscv/sbi.c | 39 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/riscv/sbi.c b/riscv/sbi.c
> index cdf8d13cc9cf..8ccdf42f902a 100644
> --- a/riscv/sbi.c
> +++ b/riscv/sbi.c
> @@ -364,10 +364,11 @@ static void check_ipi(void)
> int nr_cpus_present = cpumask_weight(&cpu_present_mask);
> int me = smp_processor_id();
> unsigned long max_hartid = 0;
> + unsigned long hartid1, hartid2;
> cpumask_t ipi_receivers;
> static prng_state ps;
> struct sbiret ret;
> - int cpu;
> + int cpu, cpu2;
>
> ps = prng_init(0xDEADBEEF);
>
> @@ -398,6 +399,42 @@ static void check_ipi(void)
> ipi_hart_check(&ipi_receivers);
> report_prefix_pop();
>
> + report_prefix_push("two in hart_mask");
> +
> + if (nr_cpus_present < 3) {
> + report_skip("3 cpus required");
> + goto end_two;
> + }
> +
> + cpu = rand_online_cpu(&ps);
> + hartid1 = cpus[cpu].hartid;
> + hartid2 = 0;
> + for_each_present_cpu(cpu2) {
> + if (cpu2 == cpu || cpu2 == me)
> + continue;
> + hartid2 = cpus[cpu2].hartid;
> + if (__builtin_labs(hartid2 - hartid1) < BITS_PER_LONG)
clang is complaining about these __builtin_labs calls not taking signed
input. I'll add this wrapper
static long __labs(long a)
{
return __builtin_labs(a);
}
> + break;
> + }
> + if (cpu2 == nr_cpus) {
> + report_skip("hartids are too sparse");
> + goto end_two;
> + }
> +
> + cpumask_clear(&ipi_done);
> + cpumask_clear(&ipi_receivers);
> + cpumask_set_cpu(cpu, &ipi_receivers);
> + cpumask_set_cpu(cpu2, &ipi_receivers);
> + on_cpu_async(cpu, ipi_hart_wait, (void *)d);
> + on_cpu_async(cpu2, ipi_hart_wait, (void *)d);
> + ret = sbi_send_ipi((1UL << __builtin_labs(hartid2 - hartid1)) | 1UL, hartid1 < hartid2 ? hartid1 : hartid2);
> + report(ret.error == SBI_SUCCESS, "ipi returned success");
> + while (!cpumask_equal(&ipi_done, &ipi_receivers))
> + cpu_relax();
> + ipi_hart_check(&ipi_receivers);
> +end_two:
> + report_prefix_pop();
> +
> report_prefix_push("broadcast");
> cpumask_clear(&ipi_done);
> cpumask_copy(&ipi_receivers, &cpu_present_mask);
> --
> 2.47.0
>
