Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index c88ed39..ea54634 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -273,7 +273,7 @@
 	return !tsx_support && (lbr_desc[lbr_format] & LBR_TSX);
 }
 
-DEFINE_STATIC_KEY_FALSE(lbr_from_quirk_key);
+static DEFINE_STATIC_KEY_FALSE(lbr_from_quirk_key);
 
 /* If quirk is enabled, ensure sign extension is 63 bits: */
 inline u64 lbr_from_signext_quirk_wr(u64 val)
@@ -488,6 +488,8 @@
 	 * be 'new'. Conversely, a new event can get installed through the
 	 * context switch path for the first time.
 	 */
+	if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
+		cpuc->lbr_pebs_users++;
 	perf_sched_cb_inc(event->ctx->pmu);
 	if (!cpuc->lbr_users++ && !event->total_time_running)
 		intel_pmu_lbr_reset();
@@ -507,8 +509,11 @@
 		task_ctx->lbr_callstack_users--;
 	}
 
+	if (x86_pmu.intel_cap.pebs_baseline && event->attr.precise_ip > 0)
+		cpuc->lbr_pebs_users--;
 	cpuc->lbr_users--;
 	WARN_ON_ONCE(cpuc->lbr_users < 0);
+	WARN_ON_ONCE(cpuc->lbr_pebs_users < 0);
 	perf_sched_cb_dec(event->ctx->pmu);
 }
 
@@ -658,7 +663,13 @@
 {
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 
-	if (!cpuc->lbr_users)
+	/*
+	 * Don't read when all LBRs users are using adaptive PEBS.
+	 *
+	 * This could be smarter and actually check the event,
+	 * but this simple approach seems to work for now.
+	 */
+	if (!cpuc->lbr_users || cpuc->lbr_users == cpuc->lbr_pebs_users)
 		return;
 
 	if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_32)
@@ -931,6 +942,7 @@
 			ret = X86_BR_ZERO_CALL;
 			break;
 		}
+		/* fall through */
 	case 0x9a: /* call far absolute */
 		ret = X86_BR_CALL;
 		break;
@@ -1079,6 +1091,28 @@
 	}
 }
 
+void intel_pmu_store_pebs_lbrs(struct pebs_lbr *lbr)
+{
+	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+	int i;
+
+	cpuc->lbr_stack.nr = x86_pmu.lbr_nr;
+	for (i = 0; i < x86_pmu.lbr_nr; i++) {
+		u64 info = lbr->lbr[i].info;
+		struct perf_branch_entry *e = &cpuc->lbr_entries[i];
+
+		e->from		= lbr->lbr[i].from;
+		e->to		= lbr->lbr[i].to;
+		e->mispred	= !!(info & LBR_INFO_MISPRED);
+		e->predicted	= !(info & LBR_INFO_MISPRED);
+		e->in_tx	= !!(info & LBR_INFO_IN_TX);
+		e->abort	= !!(info & LBR_INFO_ABORT);
+		e->cycles	= info & LBR_INFO_CYCLES;
+		e->reserved	= 0;
+	}
+	intel_pmu_lbr_filter(cpuc);
+}
+
 /*
  * Map interface branch filters onto LBR filters
  */