The DDRPERFM is the DDR Performance Monitor embedded in STM32MP1 SOC.
This perf drivers supports the read, write, activate, idle and total
time counters, described in the reference manual RM0436.
A 'bandwidth' attribute is added in the 'ddrperfm' event_source in order
to directly get the read and write bandwidths (in MB/s), from the last
read, write and total time counters reading.
This attribute is aside the 'events' attributes group because it is not
a counter, as seen by perf tool.
Signed-off-by: Gerald Baeza <gerald.baeza@xxxxxx>
---
drivers/perf/Kconfig | 6 +
drivers/perf/Makefile | 1 +
drivers/perf/stm32_ddr_pmu.c | 502 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 509 insertions(+)
create mode 100644 drivers/perf/stm32_ddr_pmu.c
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index af9bc17..d2dde80 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -96,6 +96,12 @@ config THUNDERX2_PMU
The SoC has PMU support in its L3 cache controller (L3C) and
in the DDR4 Memory Controller (DMC).
+config STM32_DDR_PMU
+ tristate "STM32 DDR PMU"
+ depends on MACH_STM32MP157
+ help
+ Support for STM32 DDR performance monitor (DDRPERFM).
+
config XGENE_PMU
depends on ARCH_XGENE
bool "APM X-Gene SoC PMU"
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index 909f27f..67505e1 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
obj-$(CONFIG_HISI_PMU) += hisilicon/
obj-$(CONFIG_QCOM_L2_PMU) += qcom_l2_pmu.o
obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
+obj-$(CONFIG_STM32_DDR_PMU) += stm32_ddr_pmu.o
obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o
obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o
obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o
diff --git a/drivers/perf/stm32_ddr_pmu.c b/drivers/perf/stm32_ddr_pmu.c
new file mode 100644
index 0000000..a7a6487
--- /dev/null
+++ b/drivers/perf/stm32_ddr_pmu.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is the STM32 DDR performance monitor (DDRPERFM) driver
+ *
+ * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
+ * Author: Gerald Baeza <gerald.baeza@xxxxxx>
+ */
+
+#include <linux/clk.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/perf_event.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define POLL_MS 4000 /* The counter roll over after ~8s @533MHz */
+#define WORD_LENGTH 4 /* Bytes */
+#define BURST_LENGTH 8 /* Words */
+
+#define DDRPERFM_CTL 0x000
+#define DDRPERFM_CFG 0x004
+#define DDRPERFM_STATUS 0x008
+#define DDRPERFM_CCR 0x00C
+#define DDRPERFM_IER 0x010
+#define DDRPERFM_ISR 0x014
+#define DDRPERFM_ICR 0x018
+#define DDRPERFM_TCNT 0x020
+#define DDRPERFM_CNT(X) (0x030 + 8 * (X))
+#define DDRPERFM_HWCFG 0x3F0
+#define DDRPERFM_VER 0x3F4
+#define DDRPERFM_ID 0x3F8
+#define DDRPERFM_SID 0x3FC
+
+#define CTL_START 0x00000001
+#define CTL_STOP 0x00000002
+#define CCR_CLEAR_ALL 0x8000000F
+#define SID_MAGIC_ID 0xA3C5DD01
+
+#define STRING "Read = %llu, Write = %llu, Read & Write = %llu (MB/s)\n"
+
+enum {
+ READ_CNT,
+ WRITE_CNT,
+ ACTIVATE_CNT,
+ IDLE_CNT,
+ TIME_CNT,
+ PMU_NR_COUNTERS
+};
+
+struct stm32_ddr_pmu {
+ struct pmu pmu;
+ void __iomem *membase;
+ struct clk *clk;
+ struct clk *clk_ddr;
+ unsigned long clk_ddr_rate;
+ struct hrtimer hrtimer;
+ ktime_t poll_period;
+ spinlock_t lock; /* for shared registers access */
+ struct perf_event *events[PMU_NR_COUNTERS];
+ u64 events_cnt[PMU_NR_COUNTERS];
+};
+
+static inline struct stm32_ddr_pmu *pmu_to_stm32_ddr_pmu(struct pmu *p)
+{
+ return container_of(p, struct stm32_ddr_pmu, pmu);
+}
+
+static inline struct stm32_ddr_pmu *hrtimer_to_stm32_ddr_pmu(struct hrtimer *h)
+{
+ return container_of(h, struct stm32_ddr_pmu, hrtimer);
+}
+
+static u64 stm32_ddr_pmu_compute_bw(struct stm32_ddr_pmu *stm32_ddr_pmu,
+ int counter)
+{
+ u64 bw = stm32_ddr_pmu->events_cnt[counter], tmp;
+ u64 div = stm32_ddr_pmu->events_cnt[TIME_CNT];
+ u32 prediv = 1, premul = 1;
+
+ if (bw && div) {
+ /* Maximize the dividend into 64 bits */
+ while ((bw < 0x8000000000000000ULL) &&
+ (premul < 0x40000000UL)) {
+ bw = bw << 1;
+ premul *= 2;
+ }
+ /* Minimize the dividor to fit in 32 bits */
+ while ((div > 0xffffffffUL) && (prediv < 0x40000000UL)) {
+ div = div >> 1;
+ prediv *= 2;
+ }
+ /* Divide counter per time and multiply per DDR settings */
+ do_div(bw, div);
+ tmp = bw * BURST_LENGTH * WORD_LENGTH;
+ tmp *= stm32_ddr_pmu->clk_ddr_rate;
+ if (tmp < bw)
+ goto error;
+ bw = tmp;
+ /* Cancel the prediv and premul factors */
+ while (prediv > 1) {
+ bw = bw >> 1;
+ prediv /= 2;
+ }
+ while (premul > 1) {
+ bw = bw >> 1;
+ premul /= 2;
+ }
+ /* Convert MHz to Hz and B to MB, to finally get MB/s */
+ tmp = bw * 1000000;
+ if (tmp < bw)
+ goto error;
+ bw = tmp;
+ premul = 1024 * 1024;
+ while (premul > 1) {
+ bw = bw >> 1;
+ premul /= 2;
+ }
+ }
+ return bw;
+
+error:
+ pr_warn("stm32-ddr-pmu: overflow detected\n");
+ return 0;
+}
+
+static void stm32_ddr_pmu_event_configure(struct perf_event *event)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = pmu_to_stm32_ddr_pmu(event->pmu);
+ unsigned long lock_flags, config_base = event->hw.config_base;
+ u32 val;
+
+ spin_lock_irqsave(&stm32_ddr_pmu->lock, lock_flags);
+ writel_relaxed(CTL_STOP, stm32_ddr_pmu->membase + DDRPERFM_CTL);
+
+ if (config_base < TIME_CNT) {
+ val = readl_relaxed(stm32_ddr_pmu->membase + DDRPERFM_CFG);
+ val |= (1 << config_base);
+ writel_relaxed(val, stm32_ddr_pmu->membase + DDRPERFM_CFG);
+ }
+ spin_unlock_irqrestore(&stm32_ddr_pmu->lock, lock_flags);
+}
+
+static void stm32_ddr_pmu_event_read(struct perf_event *event)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = pmu_to_stm32_ddr_pmu(event->pmu);
+ unsigned long flags, config_base = event->hw.config_base;
+ struct hw_perf_event *hw = &event->hw;
+ u64 prev_count, new_count, mask;
+ u32 val, offset, bit;
+
+ spin_lock_irqsave(&stm32_ddr_pmu->lock, flags);
+
+ writel_relaxed(CTL_STOP, stm32_ddr_pmu->membase + DDRPERFM_CTL);
+
+ if (config_base == TIME_CNT) {
+ offset = DDRPERFM_TCNT;
+ bit = 1 << 31;
+ } else {
+ offset = DDRPERFM_CNT(config_base);
+ bit = 1 << config_base;
+ }
+ val = readl_relaxed(stm32_ddr_pmu->membase + DDRPERFM_STATUS);
+ if (val & bit)
+ pr_warn("stm32_ddr_pmu hardware overflow\n");
+ val = readl_relaxed(stm32_ddr_pmu->membase + offset);
+ writel_relaxed(bit, stm32_ddr_pmu->membase + DDRPERFM_CCR);
+ writel_relaxed(CTL_START, stm32_ddr_pmu->membase + DDRPERFM_CTL);
+
+ do {
+ prev_count = local64_read(&hw->prev_count);
+ new_count = prev_count + val;
+ } while (local64_xchg(&hw->prev_count, new_count) != prev_count);
+
+ mask = GENMASK_ULL(31, 0);
+ local64_add(val & mask, &event->count);
+
+ if (new_count < prev_count)
+ pr_warn("STM32 DDR PMU counter saturated\n");
+
+ spin_unlock_irqrestore(&stm32_ddr_pmu->lock, flags);
+}
+
+static void stm32_ddr_pmu_event_start(struct perf_event *event, int flags)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = pmu_to_stm32_ddr_pmu(event->pmu);
+ struct hw_perf_event *hw = &event->hw;
+ unsigned long lock_flags;
+
+ if (WARN_ON_ONCE(!(hw->state & PERF_HES_STOPPED)))
+ return;
+
+ if (flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(hw->state & PERF_HES_UPTODATE));
+
+ stm32_ddr_pmu_event_configure(event);
+
+ /* Clear all counters to synchronize them, then start */
+ spin_lock_irqsave(&stm32_ddr_pmu->lock, lock_flags);
+ writel_relaxed(CCR_CLEAR_ALL, stm32_ddr_pmu->membase + DDRPERFM_CCR);
+ writel_relaxed(CTL_START, stm32_ddr_pmu->membase + DDRPERFM_CTL);
+ spin_unlock_irqrestore(&stm32_ddr_pmu->lock, lock_flags);
+
+ hw->state = 0;
+}
+
+static void stm32_ddr_pmu_event_stop(struct perf_event *event, int flags)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = pmu_to_stm32_ddr_pmu(event->pmu);
+ unsigned long lock_flags, config_base = event->hw.config_base;
+ struct hw_perf_event *hw = &event->hw;
+ u32 val, bit;
+
+ if (WARN_ON_ONCE(hw->state & PERF_HES_STOPPED))
+ return;
+
+ spin_lock_irqsave(&stm32_ddr_pmu->lock, lock_flags);
+ writel_relaxed(CTL_STOP, stm32_ddr_pmu->membase + DDRPERFM_CTL);
+ if (config_base == TIME_CNT)
+ bit = 1 << 31;
+ else
+ bit = 1 << config_base;
+ writel_relaxed(bit, stm32_ddr_pmu->membase + DDRPERFM_CCR);
+ if (config_base < TIME_CNT) {
+ val = readl_relaxed(stm32_ddr_pmu->membase + DDRPERFM_CFG);
+ val &= ~bit;
+ writel_relaxed(val, stm32_ddr_pmu->membase + DDRPERFM_CFG);
+ }
+ spin_unlock_irqrestore(&stm32_ddr_pmu->lock, lock_flags);
+
+ hw->state |= PERF_HES_STOPPED;
+
+ if (flags & PERF_EF_UPDATE) {
+ stm32_ddr_pmu_event_read(event);
+ hw->state |= PERF_HES_UPTODATE;
+ }
+}
+
+static int stm32_ddr_pmu_event_add(struct perf_event *event, int flags)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = pmu_to_stm32_ddr_pmu(event->pmu);
+ unsigned long config_base = event->hw.config_base;
+ struct hw_perf_event *hw = &event->hw;
+
+ stm32_ddr_pmu->events_cnt[config_base] = 0;
+ stm32_ddr_pmu->events[config_base] = event;
+
+ clk_enable(stm32_ddr_pmu->clk);
+ hrtimer_start(&stm32_ddr_pmu->hrtimer, stm32_ddr_pmu->poll_period,
+ HRTIMER_MODE_REL);
+
+ stm32_ddr_pmu_event_configure(event);
+
+ hw->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+
+ if (flags & PERF_EF_START)
+ stm32_ddr_pmu_event_start(event, 0);
+
+ return 0;
+}
+
+static void stm32_ddr_pmu_event_del(struct perf_event *event, int flags)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = pmu_to_stm32_ddr_pmu(event->pmu);
+ unsigned long config_base = event->hw.config_base;
+ bool stop = true;
+ int i;
+
+ stm32_ddr_pmu_event_stop(event, PERF_EF_UPDATE);
+
+ stm32_ddr_pmu->events_cnt[config_base] += local64_read(&event->count);
+ stm32_ddr_pmu->events[config_base] = NULL;
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++)
+ if (stm32_ddr_pmu->events[i])
+ stop = false;
+ if (stop)
+ hrtimer_cancel(&stm32_ddr_pmu->hrtimer);
+
+ clk_disable(stm32_ddr_pmu->clk);
+}
+
+static int stm32_ddr_pmu_event_init(struct perf_event *event)
+{
+ struct hw_perf_event *hw = &event->hw;
+
+ if (is_sampling_event(event))
+ return -EINVAL;
+
+ if (event->attach_state & PERF_ATTACH_TASK)
+ return -EINVAL;
+
+ 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)
+ return -EINVAL;
+
+ if (event->cpu < 0)
+ return -EINVAL;
+
+ hw->config_base = event->attr.config;
+
+ return 0;
+}
+
+static enum hrtimer_restart stm32_ddr_pmu_poll(struct hrtimer *hrtimer)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = hrtimer_to_stm32_ddr_pmu(hrtimer);
+ int i;
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++)
+ if (stm32_ddr_pmu->events[i])
+ stm32_ddr_pmu_event_read(stm32_ddr_pmu->events[i]);
+
+ hrtimer_forward_now(hrtimer, stm32_ddr_pmu->poll_period);
+
+ return HRTIMER_RESTART;
+}
+
+static ssize_t stm32_ddr_pmu_sysfs_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct dev_ext_attribute *eattr;
+
+ eattr = container_of(attr, struct dev_ext_attribute, attr);
+
+ return sprintf(buf, "config=0x%lx\n", (unsigned long)eattr->var);
+}
+
+static ssize_t bandwidth_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = dev_get_drvdata(dev);
+ u64 r_bw, w_bw;
+ int ret;
+
+ if (stm32_ddr_pmu->events_cnt[TIME_CNT]) {
+ r_bw = stm32_ddr_pmu_compute_bw(stm32_ddr_pmu, READ_CNT);
+ w_bw = stm32_ddr_pmu_compute_bw(stm32_ddr_pmu, WRITE_CNT);
+
+ ret = snprintf(buf, PAGE_SIZE, STRING,
+ r_bw, w_bw, (r_bw + w_bw));
+ } else {
+ ret = snprintf(buf, PAGE_SIZE, "No data available\n");
+ }
+
+ return ret;
+}
+
+#define STM32_DDR_PMU_ATTR(_name, _func, _config) \
+ (&((struct dev_ext_attribute[]) { \
+ { __ATTR(_name, 0444, _func, NULL), (void *)_config } \
+ })[0].attr.attr)
+
+#define STM32_DDR_PMU_EVENT_ATTR(_name, _config) \
+ STM32_DDR_PMU_ATTR(_name, stm32_ddr_pmu_sysfs_show, \
+ (unsigned long)_config)
+
+static struct attribute *stm32_ddr_pmu_event_attrs[] = {
+ STM32_DDR_PMU_EVENT_ATTR(read_cnt, READ_CNT),
+ STM32_DDR_PMU_EVENT_ATTR(write_cnt, WRITE_CNT),
+ STM32_DDR_PMU_EVENT_ATTR(activate_cnt, ACTIVATE_CNT),
+ STM32_DDR_PMU_EVENT_ATTR(idle_cnt, IDLE_CNT),
+ STM32_DDR_PMU_EVENT_ATTR(time_cnt, TIME_CNT),
+ NULL
+};
+
+static DEVICE_ATTR_RO(bandwidth);
+static struct attribute *stm32_ddr_pmu_bandwidth_attrs[] = {
+ &dev_attr_bandwidth.attr,
+ NULL,
+};
+
+static struct attribute_group stm32_ddr_pmu_event_attrs_group = {
+ .name = "events",
+ .attrs = stm32_ddr_pmu_event_attrs,
+};
+
+static struct attribute_group stm32_ddr_pmu_bandwidth_attrs_group = {
+ .attrs = stm32_ddr_pmu_bandwidth_attrs,
+};
+
+static const struct attribute_group *stm32_ddr_pmu_attr_groups[] = {
+ &stm32_ddr_pmu_event_attrs_group,
+ &stm32_ddr_pmu_bandwidth_attrs_group,
+ NULL,
+};
+
+static int stm32_ddr_pmu_device_probe(struct platform_device *pdev)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu;
+ struct resource *res;
+ int i, ret;
+ u32 val;
+
+ stm32_ddr_pmu = devm_kzalloc(&pdev->dev, sizeof(struct stm32_ddr_pmu),
+ GFP_KERNEL);
+ if (!stm32_ddr_pmu)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, stm32_ddr_pmu);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ stm32_ddr_pmu->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(stm32_ddr_pmu->membase)) {
+ pr_warn("Unable to get STM32 DDR PMU membase\n");
+ return PTR_ERR(stm32_ddr_pmu->membase);
+ }
+
+ stm32_ddr_pmu->clk = devm_clk_get(&pdev->dev, "bus");
+ if (IS_ERR(stm32_ddr_pmu->clk)) {
+ pr_warn("Unable to get STM32 DDR PMU clock\n");
+ return PTR_ERR(stm32_ddr_pmu->clk);
+ }
+
+ ret = clk_prepare_enable(stm32_ddr_pmu->clk);
+ if (ret) {
+ pr_warn("Unable to prepare STM32 DDR PMU clock\n");
+ return ret;
+ }
+
+ stm32_ddr_pmu->clk_ddr = devm_clk_get(&pdev->dev, "ddr");
+ if (IS_ERR(stm32_ddr_pmu->clk_ddr)) {
+ pr_warn("Unable to get STM32 DDR clock\n");
+ return PTR_ERR(stm32_ddr_pmu->clk_ddr);
+ }
+ stm32_ddr_pmu->clk_ddr_rate = clk_get_rate(stm32_ddr_pmu->clk_ddr);
+ stm32_ddr_pmu->clk_ddr_rate /= 1000000;
+
+ stm32_ddr_pmu->poll_period = ms_to_ktime(POLL_MS);
+ hrtimer_init(&stm32_ddr_pmu->hrtimer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ stm32_ddr_pmu->hrtimer.function = stm32_ddr_pmu_poll;
+ spin_lock_init(&stm32_ddr_pmu->lock);
+
+ for (i = 0; i < PMU_NR_COUNTERS; i++) {
+ stm32_ddr_pmu->events[i] = NULL;
+ stm32_ddr_pmu->events_cnt[i] = 0;
+ }
+
+ val = readl_relaxed(stm32_ddr_pmu->membase + DDRPERFM_SID);
+ if (val != SID_MAGIC_ID)
+ return -EINVAL;
+
+ stm32_ddr_pmu->pmu = (struct pmu) {
+ .task_ctx_nr = perf_invalid_context,
+ .start = stm32_ddr_pmu_event_start,
+ .stop = stm32_ddr_pmu_event_stop,
+ .add = stm32_ddr_pmu_event_add,
+ .del = stm32_ddr_pmu_event_del,
+ .event_init = stm32_ddr_pmu_event_init,
+ .attr_groups = stm32_ddr_pmu_attr_groups,
+ };
+ ret = perf_pmu_register(&stm32_ddr_pmu->pmu, "ddrperfm", -1);
+ if (ret) {
+ pr_warn("Unable to register STM32 DDR PMU\n");
+ return ret;
+ }
+
+ pr_info("stm32-ddr-pmu: probed (ID=0x%08x VER=0x%08x), DDR@%luMHz\n",
+ readl_relaxed(stm32_ddr_pmu->membase + DDRPERFM_ID),
+ readl_relaxed(stm32_ddr_pmu->membase + DDRPERFM_VER),
+ stm32_ddr_pmu->clk_ddr_rate);
+
+ clk_disable(stm32_ddr_pmu->clk);
+
+ return 0;
+}
+
+static int stm32_ddr_pmu_device_remove(struct platform_device *pdev)
+{
+ struct stm32_ddr_pmu *stm32_ddr_pmu = platform_get_drvdata(pdev);
+
+ perf_pmu_unregister(&stm32_ddr_pmu->pmu);
+
+ return 0;
+}
+
+static const struct of_device_id stm32_ddr_pmu_of_match[] = {
+ { .compatible = "st,stm32-ddr-pmu" },
+ { },
+};
+
+static struct platform_driver stm32_ddr_pmu_driver = {
+ .driver = {
+ .name = "stm32-ddr-pmu",
+ .of_match_table = of_match_ptr(stm32_ddr_pmu_of_match),
+ },
+ .probe = stm32_ddr_pmu_device_probe,
+ .remove = stm32_ddr_pmu_device_remove,
+};
+
+module_platform_driver(stm32_ddr_pmu_driver);
+
+MODULE_DESCRIPTION("Perf driver for STM32 DDR performance monitor");
+MODULE_AUTHOR("Gerald Baeza <gerald.baeza@xxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.7.4
