perf/x86/intel: Add quirk for Goldmont Plus

A ucode patch is needed for Goldmont Plus while counter freezing feature
is enabled. Otherwise, there will be some issues, e.g. PMI flood with
some events.

Add a quirk to check microcode version. If the system starts with the
wrong ucode, leave the counter-freezing feature permanently disabled.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Link: http://lkml.kernel.org/r/1533712328-2834-3-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index f17cf6c3ec6f..ab01ef9ddd77 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3839,6 +3839,40 @@ static __init void intel_nehalem_quirk(void)
         }
 }
 
+static bool intel_glp_counter_freezing_broken(int cpu)
+{
+        u32 rev = UINT_MAX; /* default to broken for unknown stepping */
+
+        switch (cpu_data(cpu).x86_stepping) {
+        case 1:
+                rev = 0x28;
+                break;
+        case 8:
+                rev = 0x6;
+                break;
+        }
+
+        return (cpu_data(cpu).microcode < rev);
+}
+
+static __init void intel_glp_counter_freezing_quirk(void)
+{
+        /* Check if it's already disabled */
+        if (disable_counter_freezing)
+                return;
+
+        /*
+         * If the system starts with the wrong ucode, leave the
+         * counter-freezing feature permanently disabled.
+         */
+        if (intel_glp_counter_freezing_broken(raw_smp_processor_id())) {
+                pr_info("PMU counter freezing disabled due to CPU errata,"
+                        "please upgrade microcode\n");
+                x86_pmu.counter_freezing = false;
+                x86_pmu.handle_irq = intel_pmu_handle_irq;
+        }
+}
+
 /*
  * enable software workaround for errata:
  * SNB: BJ122
@@ -4188,6 +4222,7 @@ __init int intel_pmu_init(void)
                 break;
 
         case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
+                x86_add_quirk(intel_glp_counter_freezing_quirk);
                 memcpy(hw_cache_event_ids, glp_hw_cache_event_ids,
                        sizeof(hw_cache_event_ids));
                 memcpy(hw_cache_extra_regs, glp_hw_cache_extra_regs,