4.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: Madhavan Srinivasan <[email protected]> commit 20dd4c624d25156d5ec3345bbb690b98175ef879 upstream. In case of continous sampling (non-marked), the code currently sets MMCRA[SDAR_MODE] to 0b01 (Update on TLB miss) for Power9 DD1. On DD2 and later it copies the sdar_mode value from the event code, which for most events is 0b00 (No updates). However we must set a non-zero value for SDAR_MODE when doing continuous sampling, so honor the event code, unless it's zero, in which case we use use 0b01 (Update on TLB miss). Fixes: 78b4416aa249 ("powerpc/perf: Handle sdar_mode for marked event in power9") Signed-off-by: Madhavan Srinivasan <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/powerpc/perf/isa207-common.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/arch/powerpc/perf/isa207-common.c +++ b/arch/powerpc/perf/isa207-common.c @@ -90,13 +90,15 @@ static void mmcra_sdar_mode(u64 event, u * MMCRA[SDAR_MODE] will be set to 0b01 * For rest * MMCRA[SDAR_MODE] will be set from event code. + * If sdar_mode from event is zero, default to 0b01. Hardware + * requires that we set a non-zero value. */ if (cpu_has_feature(CPU_FTR_ARCH_300)) { if (is_event_marked(event) || (*mmcra & MMCRA_SAMPLE_ENABLE)) *mmcra &= MMCRA_SDAR_MODE_NO_UPDATES; - else if (!cpu_has_feature(CPU_FTR_POWER9_DD1)) + else if (!cpu_has_feature(CPU_FTR_POWER9_DD1) && p9_SDAR_MODE(event)) *mmcra |= p9_SDAR_MODE(event) << MMCRA_SDAR_MODE_SHIFT; - else if (cpu_has_feature(CPU_FTR_POWER9_DD1)) + else *mmcra |= MMCRA_SDAR_MODE_TLB; } else *mmcra |= MMCRA_SDAR_MODE_TLB;
