v4.19.13 snapshot.
diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
new file mode 100644
index 0000000..04b3bf7
--- /dev/null
+++ b/arch/arm/mach-imx/mmdc.c
@@ -0,0 +1,588 @@
+/*
+ * Copyright 2017 NXP
+ * Copyright 2011,2016 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/perf_event.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+#define MMDC_MAPSR		0x404
+#define BP_MMDC_MAPSR_PSD	0
+#define BP_MMDC_MAPSR_PSS	4
+
+#define MMDC_MDMISC		0x18
+#define BM_MMDC_MDMISC_DDR_TYPE	0x18
+#define BP_MMDC_MDMISC_DDR_TYPE	0x3
+
+#define TOTAL_CYCLES		0x0
+#define BUSY_CYCLES		0x1
+#define READ_ACCESSES		0x2
+#define WRITE_ACCESSES		0x3
+#define READ_BYTES		0x4
+#define WRITE_BYTES		0x5
+
+/* Enables, resets, freezes, overflow profiling*/
+#define DBG_DIS			0x0
+#define DBG_EN			0x1
+#define DBG_RST			0x2
+#define PRF_FRZ			0x4
+#define CYC_OVF			0x8
+#define PROFILE_SEL		0x10
+
+#define MMDC_MADPCR0	0x410
+#define MMDC_MADPCR1	0x414
+#define MMDC_MADPSR0	0x418
+#define MMDC_MADPSR1	0x41C
+#define MMDC_MADPSR2	0x420
+#define MMDC_MADPSR3	0x424
+#define MMDC_MADPSR4	0x428
+#define MMDC_MADPSR5	0x42C
+
+#define MMDC_NUM_COUNTERS	6
+
+#define MMDC_FLAG_PROFILE_SEL	0x1
+#define MMDC_PRF_AXI_ID_CLEAR	0x0
+
+#define to_mmdc_pmu(p) container_of(p, struct mmdc_pmu, pmu)
+
+static int ddr_type;
+
+struct fsl_mmdc_devtype_data {
+	unsigned int flags;
+};
+
+static const struct fsl_mmdc_devtype_data imx6q_data = {
+};
+
+static const struct fsl_mmdc_devtype_data imx6qp_data = {
+	.flags = MMDC_FLAG_PROFILE_SEL,
+};
+
+static const struct of_device_id imx_mmdc_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-mmdc", .data = (void *)&imx6q_data},
+	{ .compatible = "fsl,imx6qp-mmdc", .data = (void *)&imx6qp_data},
+	{ /* sentinel */ }
+};
+
+#ifdef CONFIG_PERF_EVENTS
+
+static enum cpuhp_state cpuhp_mmdc_state;
+static DEFINE_IDA(mmdc_ida);
+
+PMU_EVENT_ATTR_STRING(total-cycles, mmdc_pmu_total_cycles, "event=0x00")
+PMU_EVENT_ATTR_STRING(busy-cycles, mmdc_pmu_busy_cycles, "event=0x01")
+PMU_EVENT_ATTR_STRING(read-accesses, mmdc_pmu_read_accesses, "event=0x02")
+PMU_EVENT_ATTR_STRING(write-accesses, mmdc_pmu_write_accesses, "event=0x03")
+PMU_EVENT_ATTR_STRING(read-bytes, mmdc_pmu_read_bytes, "event=0x04")
+PMU_EVENT_ATTR_STRING(read-bytes.unit, mmdc_pmu_read_bytes_unit, "MB");
+PMU_EVENT_ATTR_STRING(read-bytes.scale, mmdc_pmu_read_bytes_scale, "0.000001");
+PMU_EVENT_ATTR_STRING(write-bytes, mmdc_pmu_write_bytes, "event=0x05")
+PMU_EVENT_ATTR_STRING(write-bytes.unit, mmdc_pmu_write_bytes_unit, "MB");
+PMU_EVENT_ATTR_STRING(write-bytes.scale, mmdc_pmu_write_bytes_scale, "0.000001");
+
+struct mmdc_pmu {
+	struct pmu pmu;
+	void __iomem *mmdc_base;
+	cpumask_t cpu;
+	struct hrtimer hrtimer;
+	unsigned int active_events;
+	struct device *dev;
+	struct perf_event *mmdc_events[MMDC_NUM_COUNTERS];
+	struct hlist_node node;
+	struct fsl_mmdc_devtype_data *devtype_data;
+};
+
+/*
+ * Polling period is set to one second, overflow of total-cycles (the fastest
+ * increasing counter) takes ten seconds so one second is safe
+ */
+static unsigned int mmdc_pmu_poll_period_us = 1000000;
+
+module_param_named(pmu_pmu_poll_period_us, mmdc_pmu_poll_period_us, uint,
+		S_IRUGO | S_IWUSR);
+
+static ktime_t mmdc_pmu_timer_period(void)
+{
+	return ns_to_ktime((u64)mmdc_pmu_poll_period_us * 1000);
+}
+
+static ssize_t mmdc_pmu_cpumask_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct mmdc_pmu *pmu_mmdc = dev_get_drvdata(dev);
+
+	return cpumap_print_to_pagebuf(true, buf, &pmu_mmdc->cpu);
+}
+
+static struct device_attribute mmdc_pmu_cpumask_attr =
+	__ATTR(cpumask, S_IRUGO, mmdc_pmu_cpumask_show, NULL);
+
+static struct attribute *mmdc_pmu_cpumask_attrs[] = {
+	&mmdc_pmu_cpumask_attr.attr,
+	NULL,
+};
+
+static struct attribute_group mmdc_pmu_cpumask_attr_group = {
+	.attrs = mmdc_pmu_cpumask_attrs,
+};
+
+static struct attribute *mmdc_pmu_events_attrs[] = {
+	&mmdc_pmu_total_cycles.attr.attr,
+	&mmdc_pmu_busy_cycles.attr.attr,
+	&mmdc_pmu_read_accesses.attr.attr,
+	&mmdc_pmu_write_accesses.attr.attr,
+	&mmdc_pmu_read_bytes.attr.attr,
+	&mmdc_pmu_read_bytes_unit.attr.attr,
+	&mmdc_pmu_read_bytes_scale.attr.attr,
+	&mmdc_pmu_write_bytes.attr.attr,
+	&mmdc_pmu_write_bytes_unit.attr.attr,
+	&mmdc_pmu_write_bytes_scale.attr.attr,
+	NULL,
+};
+
+static struct attribute_group mmdc_pmu_events_attr_group = {
+	.name = "events",
+	.attrs = mmdc_pmu_events_attrs,
+};
+
+PMU_FORMAT_ATTR(event, "config:0-63");
+PMU_FORMAT_ATTR(axi_id, "config1:0-63");
+
+static struct attribute *mmdc_pmu_format_attrs[] = {
+	&format_attr_event.attr,
+	&format_attr_axi_id.attr,
+	NULL,
+};
+
+static struct attribute_group mmdc_pmu_format_attr_group = {
+	.name = "format",
+	.attrs = mmdc_pmu_format_attrs,
+};
+
+static const struct attribute_group *attr_groups[] = {
+	&mmdc_pmu_events_attr_group,
+	&mmdc_pmu_format_attr_group,
+	&mmdc_pmu_cpumask_attr_group,
+	NULL,
+};
+
+static u32 mmdc_pmu_read_counter(struct mmdc_pmu *pmu_mmdc, int cfg)
+{
+	void __iomem *mmdc_base, *reg;
+
+	mmdc_base = pmu_mmdc->mmdc_base;
+
+	switch (cfg) {
+	case TOTAL_CYCLES:
+		reg = mmdc_base + MMDC_MADPSR0;
+		break;
+	case BUSY_CYCLES:
+		reg = mmdc_base + MMDC_MADPSR1;
+		break;
+	case READ_ACCESSES:
+		reg = mmdc_base + MMDC_MADPSR2;
+		break;
+	case WRITE_ACCESSES:
+		reg = mmdc_base + MMDC_MADPSR3;
+		break;
+	case READ_BYTES:
+		reg = mmdc_base + MMDC_MADPSR4;
+		break;
+	case WRITE_BYTES:
+		reg = mmdc_base + MMDC_MADPSR5;
+		break;
+	default:
+		return WARN_ONCE(1,
+			"invalid configuration %d for mmdc counter", cfg);
+	}
+	return readl(reg);
+}
+
+static int mmdc_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct mmdc_pmu *pmu_mmdc = hlist_entry_safe(node, struct mmdc_pmu, node);
+	int target;
+
+	if (!cpumask_test_and_clear_cpu(cpu, &pmu_mmdc->cpu))
+		return 0;
+
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	perf_pmu_migrate_context(&pmu_mmdc->pmu, cpu, target);
+	cpumask_set_cpu(target, &pmu_mmdc->cpu);
+
+	return 0;
+}
+
+static bool mmdc_pmu_group_event_is_valid(struct perf_event *event,
+					  struct pmu *pmu,
+					  unsigned long *used_counters)
+{
+	int cfg = event->attr.config;
+
+	if (is_software_event(event))
+		return true;
+
+	if (event->pmu != pmu)
+		return false;
+
+	return !test_and_set_bit(cfg, used_counters);
+}
+
+/*
+ * Each event has a single fixed-purpose counter, so we can only have a
+ * single active event for each at any point in time. Here we just check
+ * for duplicates, and rely on mmdc_pmu_event_init to verify that the HW
+ * event numbers are valid.
+ */
+static bool mmdc_pmu_group_is_valid(struct perf_event *event)
+{
+	struct pmu *pmu = event->pmu;
+	struct perf_event *leader = event->group_leader;
+	struct perf_event *sibling;
+	unsigned long counter_mask = 0;
+
+	set_bit(leader->attr.config, &counter_mask);
+
+	if (event != leader) {
+		if (!mmdc_pmu_group_event_is_valid(event, pmu, &counter_mask))
+			return false;
+	}
+
+	for_each_sibling_event(sibling, leader) {
+		if (!mmdc_pmu_group_event_is_valid(sibling, pmu, &counter_mask))
+			return false;
+	}
+
+	return true;
+}
+
+static int mmdc_pmu_event_init(struct perf_event *event)
+{
+	struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
+	int cfg = event->attr.config;
+
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
+		return -EOPNOTSUPP;
+
+	if (event->cpu < 0) {
+		dev_warn(pmu_mmdc->dev, "Can't provide per-task data!\n");
+		return -EOPNOTSUPP;
+	}
+
+	if (event->attr.exclude_user		||
+			event->attr.exclude_kernel	||
+			event->attr.exclude_hv		||
+			event->attr.exclude_idle	||
+			event->attr.exclude_host	||
+			event->attr.exclude_guest	||
+			event->attr.sample_period)
+		return -EINVAL;
+
+	if (cfg < 0 || cfg >= MMDC_NUM_COUNTERS)
+		return -EINVAL;
+
+	if (!mmdc_pmu_group_is_valid(event))
+		return -EINVAL;
+
+	event->cpu = cpumask_first(&pmu_mmdc->cpu);
+	return 0;
+}
+
+static void mmdc_pmu_event_update(struct perf_event *event)
+{
+	struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	u64 delta, prev_raw_count, new_raw_count;
+
+	do {
+		prev_raw_count = local64_read(&hwc->prev_count);
+		new_raw_count = mmdc_pmu_read_counter(pmu_mmdc,
+						      event->attr.config);
+	} while (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+		new_raw_count) != prev_raw_count);
+
+	delta = (new_raw_count - prev_raw_count) & 0xFFFFFFFF;
+
+	local64_add(delta, &event->count);
+}
+
+static void mmdc_pmu_event_start(struct perf_event *event, int flags)
+{
+	struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	void __iomem *mmdc_base, *reg;
+	u32 val;
+
+	mmdc_base = pmu_mmdc->mmdc_base;
+	reg = mmdc_base + MMDC_MADPCR0;
+
+	/*
+	 * hrtimer is required because mmdc does not provide an interrupt so
+	 * polling is necessary
+	 */
+	hrtimer_start(&pmu_mmdc->hrtimer, mmdc_pmu_timer_period(),
+			HRTIMER_MODE_REL_PINNED);
+
+	local64_set(&hwc->prev_count, 0);
+
+	writel(DBG_RST, reg);
+
+	/*
+	 * Write the AXI id parameter to MADPCR1.
+	 */
+	val = event->attr.config1;
+	reg = mmdc_base + MMDC_MADPCR1;
+	writel(val, reg);
+
+	reg = mmdc_base + MMDC_MADPCR0;
+	val = DBG_EN;
+	if (pmu_mmdc->devtype_data->flags & MMDC_FLAG_PROFILE_SEL)
+		val |= PROFILE_SEL;
+
+	writel(val, reg);
+}
+
+static int mmdc_pmu_event_add(struct perf_event *event, int flags)
+{
+	struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	int cfg = event->attr.config;
+
+	if (flags & PERF_EF_START)
+		mmdc_pmu_event_start(event, flags);
+
+	if (pmu_mmdc->mmdc_events[cfg] != NULL)
+		return -EAGAIN;
+
+	pmu_mmdc->mmdc_events[cfg] = event;
+	pmu_mmdc->active_events++;
+
+	local64_set(&hwc->prev_count, mmdc_pmu_read_counter(pmu_mmdc, cfg));
+
+	return 0;
+}
+
+static void mmdc_pmu_event_stop(struct perf_event *event, int flags)
+{
+	struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
+	void __iomem *mmdc_base, *reg;
+
+	mmdc_base = pmu_mmdc->mmdc_base;
+	reg = mmdc_base + MMDC_MADPCR0;
+
+	writel(PRF_FRZ, reg);
+
+	reg = mmdc_base + MMDC_MADPCR1;
+	writel(MMDC_PRF_AXI_ID_CLEAR, reg);
+
+	mmdc_pmu_event_update(event);
+}
+
+static void mmdc_pmu_event_del(struct perf_event *event, int flags)
+{
+	struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
+	int cfg = event->attr.config;
+
+	pmu_mmdc->mmdc_events[cfg] = NULL;
+	pmu_mmdc->active_events--;
+
+	if (pmu_mmdc->active_events == 0)
+		hrtimer_cancel(&pmu_mmdc->hrtimer);
+
+	mmdc_pmu_event_stop(event, PERF_EF_UPDATE);
+}
+
+static void mmdc_pmu_overflow_handler(struct mmdc_pmu *pmu_mmdc)
+{
+	int i;
+
+	for (i = 0; i < MMDC_NUM_COUNTERS; i++) {
+		struct perf_event *event = pmu_mmdc->mmdc_events[i];
+
+		if (event)
+			mmdc_pmu_event_update(event);
+	}
+}
+
+static enum hrtimer_restart mmdc_pmu_timer_handler(struct hrtimer *hrtimer)
+{
+	struct mmdc_pmu *pmu_mmdc = container_of(hrtimer, struct mmdc_pmu,
+			hrtimer);
+
+	mmdc_pmu_overflow_handler(pmu_mmdc);
+	hrtimer_forward_now(hrtimer, mmdc_pmu_timer_period());
+
+	return HRTIMER_RESTART;
+}
+
+static int mmdc_pmu_init(struct mmdc_pmu *pmu_mmdc,
+		void __iomem *mmdc_base, struct device *dev)
+{
+	int mmdc_num;
+
+	*pmu_mmdc = (struct mmdc_pmu) {
+		.pmu = (struct pmu) {
+			.task_ctx_nr    = perf_invalid_context,
+			.attr_groups    = attr_groups,
+			.event_init     = mmdc_pmu_event_init,
+			.add            = mmdc_pmu_event_add,
+			.del            = mmdc_pmu_event_del,
+			.start          = mmdc_pmu_event_start,
+			.stop           = mmdc_pmu_event_stop,
+			.read           = mmdc_pmu_event_update,
+		},
+		.mmdc_base = mmdc_base,
+		.dev = dev,
+		.active_events = 0,
+	};
+
+	mmdc_num = ida_simple_get(&mmdc_ida, 0, 0, GFP_KERNEL);
+
+	return mmdc_num;
+}
+
+static int imx_mmdc_remove(struct platform_device *pdev)
+{
+	struct mmdc_pmu *pmu_mmdc = platform_get_drvdata(pdev);
+
+	cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
+	perf_pmu_unregister(&pmu_mmdc->pmu);
+	kfree(pmu_mmdc);
+	return 0;
+}
+
+static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_base)
+{
+	struct mmdc_pmu *pmu_mmdc;
+	char *name;
+	int mmdc_num;
+	int ret;
+	const struct of_device_id *of_id =
+		of_match_device(imx_mmdc_dt_ids, &pdev->dev);
+
+	pmu_mmdc = kzalloc(sizeof(*pmu_mmdc), GFP_KERNEL);
+	if (!pmu_mmdc) {
+		pr_err("failed to allocate PMU device!\n");
+		return -ENOMEM;
+	}
+
+	/* The first instance registers the hotplug state */
+	if (!cpuhp_mmdc_state) {
+		ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+					      "perf/arm/mmdc:online", NULL,
+					      mmdc_pmu_offline_cpu);
+		if (ret < 0) {
+			pr_err("cpuhp_setup_state_multi failed\n");
+			goto pmu_free;
+		}
+		cpuhp_mmdc_state = ret;
+	}
+
+	mmdc_num = mmdc_pmu_init(pmu_mmdc, mmdc_base, &pdev->dev);
+	if (mmdc_num == 0)
+		name = "mmdc";
+	else
+		name = devm_kasprintf(&pdev->dev,
+				GFP_KERNEL, "mmdc%d", mmdc_num);
+
+	pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data *)of_id->data;
+
+	hrtimer_init(&pmu_mmdc->hrtimer, CLOCK_MONOTONIC,
+			HRTIMER_MODE_REL);
+	pmu_mmdc->hrtimer.function = mmdc_pmu_timer_handler;
+
+	cpumask_set_cpu(raw_smp_processor_id(), &pmu_mmdc->cpu);
+
+	/* Register the pmu instance for cpu hotplug */
+	cpuhp_state_add_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
+
+	ret = perf_pmu_register(&(pmu_mmdc->pmu), name, -1);
+	if (ret)
+		goto pmu_register_err;
+
+	platform_set_drvdata(pdev, pmu_mmdc);
+	return 0;
+
+pmu_register_err:
+	pr_warn("MMDC Perf PMU failed (%d), disabled\n", ret);
+	cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
+	hrtimer_cancel(&pmu_mmdc->hrtimer);
+pmu_free:
+	kfree(pmu_mmdc);
+	return ret;
+}
+
+#else
+#define imx_mmdc_remove NULL
+#define imx_mmdc_perf_init(pdev, mmdc_base) 0
+#endif
+
+static int imx_mmdc_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	void __iomem *mmdc_base, *reg;
+	u32 val;
+
+	mmdc_base = of_iomap(np, 0);
+	WARN_ON(!mmdc_base);
+
+	reg = mmdc_base + MMDC_MDMISC;
+	/* Get ddr type */
+	val = readl_relaxed(reg);
+	ddr_type = (val & BM_MMDC_MDMISC_DDR_TYPE) >>
+		 BP_MMDC_MDMISC_DDR_TYPE;
+
+	reg = mmdc_base + MMDC_MAPSR;
+
+	/* Enable automatic power saving */
+	val = readl_relaxed(reg);
+	val &= ~(1 << BP_MMDC_MAPSR_PSD);
+	writel_relaxed(val, reg);
+
+	return imx_mmdc_perf_init(pdev, mmdc_base);
+}
+
+int imx_mmdc_get_ddr_type(void)
+{
+	return ddr_type;
+}
+
+static struct platform_driver imx_mmdc_driver = {
+	.driver		= {
+		.name	= "imx-mmdc",
+		.of_match_table = imx_mmdc_dt_ids,
+	},
+	.probe		= imx_mmdc_probe,
+	.remove		= imx_mmdc_remove,
+};
+
+static int __init imx_mmdc_init(void)
+{
+	return platform_driver_register(&imx_mmdc_driver);
+}
+postcore_initcall(imx_mmdc_init);