v4.19.13 snapshot.
diff --git a/arch/powerpc/perf/8xx-pmu.c b/arch/powerpc/perf/8xx-pmu.c
new file mode 100644
index 0000000..6c0020d
--- /dev/null
+++ b/arch/powerpc/perf/8xx-pmu.c
@@ -0,0 +1,217 @@
+/*
+ * Performance event support - PPC 8xx
+ *
+ * Copyright 2016 Christophe Leroy, CS Systemes d'Information
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/perf_event.h>
+#include <linux/percpu.h>
+#include <linux/hardirq.h>
+#include <asm/pmc.h>
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/ptrace.h>
+#include <asm/code-patching.h>
+
+#define PERF_8xx_ID_CPU_CYCLES		1
+#define PERF_8xx_ID_HW_INSTRUCTIONS	2
+#define PERF_8xx_ID_ITLB_LOAD_MISS	3
+#define PERF_8xx_ID_DTLB_LOAD_MISS	4
+
+#define C(x)	PERF_COUNT_HW_CACHE_##x
+#define DTLB_LOAD_MISS	(C(DTLB) | (C(OP_READ) << 8) | (C(RESULT_MISS) << 16))
+#define ITLB_LOAD_MISS	(C(ITLB) | (C(OP_READ) << 8) | (C(RESULT_MISS) << 16))
+
+extern unsigned long itlb_miss_counter, dtlb_miss_counter;
+extern atomic_t instruction_counter;
+extern unsigned int itlb_miss_perf, dtlb_miss_perf;
+extern unsigned int itlb_miss_exit_1, itlb_miss_exit_2;
+extern unsigned int dtlb_miss_exit_1, dtlb_miss_exit_2, dtlb_miss_exit_3;
+
+static atomic_t insn_ctr_ref;
+static atomic_t itlb_miss_ref;
+static atomic_t dtlb_miss_ref;
+
+static s64 get_insn_ctr(void)
+{
+	int ctr;
+	unsigned long counta;
+
+	do {
+		ctr = atomic_read(&instruction_counter);
+		counta = mfspr(SPRN_COUNTA);
+	} while (ctr != atomic_read(&instruction_counter));
+
+	return ((s64)ctr << 16) | (counta >> 16);
+}
+
+static int event_type(struct perf_event *event)
+{
+	switch (event->attr.type) {
+	case PERF_TYPE_HARDWARE:
+		if (event->attr.config == PERF_COUNT_HW_CPU_CYCLES)
+			return PERF_8xx_ID_CPU_CYCLES;
+		if (event->attr.config == PERF_COUNT_HW_INSTRUCTIONS)
+			return PERF_8xx_ID_HW_INSTRUCTIONS;
+		break;
+	case PERF_TYPE_HW_CACHE:
+		if (event->attr.config == ITLB_LOAD_MISS)
+			return PERF_8xx_ID_ITLB_LOAD_MISS;
+		if (event->attr.config == DTLB_LOAD_MISS)
+			return PERF_8xx_ID_DTLB_LOAD_MISS;
+		break;
+	case PERF_TYPE_RAW:
+		break;
+	default:
+		return -ENOENT;
+	}
+	return -EOPNOTSUPP;
+}
+
+static int mpc8xx_pmu_event_init(struct perf_event *event)
+{
+	int type = event_type(event);
+
+	if (type < 0)
+		return type;
+	return 0;
+}
+
+static int mpc8xx_pmu_add(struct perf_event *event, int flags)
+{
+	int type = event_type(event);
+	s64 val = 0;
+
+	if (type < 0)
+		return type;
+
+	switch (type) {
+	case PERF_8xx_ID_CPU_CYCLES:
+		val = get_tb();
+		break;
+	case PERF_8xx_ID_HW_INSTRUCTIONS:
+		if (atomic_inc_return(&insn_ctr_ref) == 1)
+			mtspr(SPRN_ICTRL, 0xc0080007);
+		val = get_insn_ctr();
+		break;
+	case PERF_8xx_ID_ITLB_LOAD_MISS:
+		if (atomic_inc_return(&itlb_miss_ref) == 1) {
+			unsigned long target = (unsigned long)&itlb_miss_perf;
+
+			patch_branch(&itlb_miss_exit_1, target, 0);
+#ifndef CONFIG_PIN_TLB_TEXT
+			patch_branch(&itlb_miss_exit_2, target, 0);
+#endif
+		}
+		val = itlb_miss_counter;
+		break;
+	case PERF_8xx_ID_DTLB_LOAD_MISS:
+		if (atomic_inc_return(&dtlb_miss_ref) == 1) {
+			unsigned long target = (unsigned long)&dtlb_miss_perf;
+
+			patch_branch(&dtlb_miss_exit_1, target, 0);
+			patch_branch(&dtlb_miss_exit_2, target, 0);
+			patch_branch(&dtlb_miss_exit_3, target, 0);
+		}
+		val = dtlb_miss_counter;
+		break;
+	}
+	local64_set(&event->hw.prev_count, val);
+	return 0;
+}
+
+static void mpc8xx_pmu_read(struct perf_event *event)
+{
+	int type = event_type(event);
+	s64 prev, val = 0, delta = 0;
+
+	if (type < 0)
+		return;
+
+	do {
+		prev = local64_read(&event->hw.prev_count);
+		switch (type) {
+		case PERF_8xx_ID_CPU_CYCLES:
+			val = get_tb();
+			delta = 16 * (val - prev);
+			break;
+		case PERF_8xx_ID_HW_INSTRUCTIONS:
+			val = get_insn_ctr();
+			delta = prev - val;
+			if (delta < 0)
+				delta += 0x1000000000000LL;
+			break;
+		case PERF_8xx_ID_ITLB_LOAD_MISS:
+			val = itlb_miss_counter;
+			delta = (s64)((s32)val - (s32)prev);
+			break;
+		case PERF_8xx_ID_DTLB_LOAD_MISS:
+			val = dtlb_miss_counter;
+			delta = (s64)((s32)val - (s32)prev);
+			break;
+		}
+	} while (local64_cmpxchg(&event->hw.prev_count, prev, val) != prev);
+
+	local64_add(delta, &event->count);
+}
+
+static void mpc8xx_pmu_del(struct perf_event *event, int flags)
+{
+	/* mfspr r10, SPRN_SPRG_SCRATCH0 */
+	unsigned int insn = PPC_INST_MFSPR | __PPC_RS(R10) |
+			    __PPC_SPR(SPRN_SPRG_SCRATCH0);
+
+	mpc8xx_pmu_read(event);
+
+	/* If it was the last user, stop counting to avoid useles overhead */
+	switch (event_type(event)) {
+	case PERF_8xx_ID_CPU_CYCLES:
+		break;
+	case PERF_8xx_ID_HW_INSTRUCTIONS:
+		if (atomic_dec_return(&insn_ctr_ref) == 0)
+			mtspr(SPRN_ICTRL, 7);
+		break;
+	case PERF_8xx_ID_ITLB_LOAD_MISS:
+		if (atomic_dec_return(&itlb_miss_ref) == 0) {
+			patch_instruction(&itlb_miss_exit_1, insn);
+#ifndef CONFIG_PIN_TLB_TEXT
+			patch_instruction(&itlb_miss_exit_2, insn);
+#endif
+		}
+		break;
+	case PERF_8xx_ID_DTLB_LOAD_MISS:
+		if (atomic_dec_return(&dtlb_miss_ref) == 0) {
+			patch_instruction(&dtlb_miss_exit_1, insn);
+			patch_instruction(&dtlb_miss_exit_2, insn);
+			patch_instruction(&dtlb_miss_exit_3, insn);
+		}
+		break;
+	}
+}
+
+static struct pmu mpc8xx_pmu = {
+	.event_init	= mpc8xx_pmu_event_init,
+	.add		= mpc8xx_pmu_add,
+	.del		= mpc8xx_pmu_del,
+	.read		= mpc8xx_pmu_read,
+	.capabilities	= PERF_PMU_CAP_NO_INTERRUPT |
+			  PERF_PMU_CAP_NO_NMI,
+};
+
+static int init_mpc8xx_pmu(void)
+{
+	mtspr(SPRN_ICTRL, 7);
+	mtspr(SPRN_CMPA, 0);
+	mtspr(SPRN_COUNTA, 0xffff);
+
+	return perf_pmu_register(&mpc8xx_pmu, "cpu", PERF_TYPE_RAW);
+}
+
+early_initcall(init_mpc8xx_pmu);