The presence or absence of EBB is advertised to userspace via the presence or absence of PPC_FEATURE2_EBB in cpu_user_features2.
Because the kernel can be built without PMU support, we should only add PPC_FEATURE2_EBB to cpu_user_features2 when we successfully register the power8 PMU support. Signed-off-by: Michael Ellerman <mich...@ellerman.id.au> --- arch/powerpc/perf/power8-pmu.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c index 96a64d6..09def19 100644 --- a/arch/powerpc/perf/power8-pmu.c +++ b/arch/powerpc/perf/power8-pmu.c @@ -621,10 +621,19 @@ static struct power_pmu power8_pmu = { static int __init init_power8_pmu(void) { + int rc; + if (!cur_cpu_spec->oprofile_cpu_type || strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power8")) return -ENODEV; - return register_power_pmu(&power8_pmu); + rc = register_power_pmu(&power8_pmu); + if (rc) + return rc; + + /* Tell userspace that EBB is supported */ + cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_EBB; + + return 0; } early_initcall(init_power8_pmu); -- 1.7.10.4 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev