Re: [PATCH] Added perf functionality to mmdc driver
From: Zhi Li
Date: Fri Aug 05 2016 - 10:38:54 EST
On Fri, Aug 5, 2016 at 9:35 AM, Zhengyu Shen <zhengyu.shen@xxxxxxx> wrote:
> $ perf stat -e mmdc/busy-cycles/,mmdc/read-accesses/,mmdc/read-bytes/,mmdc/total-cycles/,mmdc/write-accesses/,mmdc/write-bytes/ dd if=/dev/zero of=/dev/null bs=1M count=5000
> Performance counter stats for 'dd if=/dev/zero of=/dev/null bs=1M count=5000':
>
> 898021787 mmdc/busy-cycles/
> 14819600 mmdc/read-accesses/
> 471.30 MB mmdc/read-bytes/
> 2815419216 mmdc/total-cycles/
> 13367354 mmdc/write-accesses/
> 427.76 MB mmdc/write-bytes/
>
> 5.334757334 seconds time elapsed
>
> Signed-off-by: Zhengyu Shen <zhengyu.shen@xxxxxxx>
Acked-by: Frank.Li@xxxxxxx
> ---
> arch/arm/mach-imx/mmdc.c | 206 ++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 205 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-imx/mmdc.c b/arch/arm/mach-imx/mmdc.c
> index db9621c..48f3a0b 100644
> --- a/arch/arm/mach-imx/mmdc.c
> +++ b/arch/arm/mach-imx/mmdc.c
> @@ -1,5 +1,5 @@
> /*
> - * Copyright 2011 Freescale Semiconductor, Inc.
> + * Copyright 2011,2016 Freescale Semiconductor, Inc.
> * Copyright 2011 Linaro Ltd.
> *
> * The code contained herein is licensed under the GNU General Public
> @@ -16,6 +16,8 @@
> #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"
>
> @@ -27,12 +29,198 @@
> #define BM_MMDC_MDMISC_DDR_TYPE 0x18
> #define BP_MMDC_MDMISC_DDR_TYPE 0x3
>
> +#define TOTAL_CYCLES 0x1
> +#define BUSY_CYCLES 0x2
> +#define READ_ACCESSES 0x3
> +#define WRITE_ACCESSES 0x4
> +#define READ_BYTES 0x5
> +#define WRITE_BYTES 0x6
> +
> +#define DBG_EN 0x1
> +#define DBG_RST 0x2
> +#define PRF_FRZ 0x4
> +#define CYC_OVF 0x8
> +
> +#define MMDC_MADPCR0 0x410
> +#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 to_mmdc_pmu(p) (container_of(p, struct mmdc_pmu, pmu))
> +
> static int ddr_type;
>
> +PMU_EVENT_ATTR_STRING(total-cycles, evattr_total_cycles, "event=0x01")
> +PMU_EVENT_ATTR_STRING(busy-cycles, evattr_busy_cycles, "event=0x02")
> +PMU_EVENT_ATTR_STRING(read-accesses, evattr_read_accesses, "event=0x03")
> +PMU_EVENT_ATTR_STRING(write-accesses, evattr_write_accesses, "config=0x04")
> +PMU_EVENT_ATTR_STRING(read-bytes, evattr_read_bytes, "event=0x05")
> +PMU_EVENT_ATTR_STRING(read-bytes.unit, evattr_read_bytes_unit, "MB");
> +PMU_EVENT_ATTR_STRING(read-bytes.scale, evattr_read_bytes_scale, "0.000001");
> +PMU_EVENT_ATTR_STRING(write-bytes, evattr_write_bytes, "event=0x06")
> +PMU_EVENT_ATTR_STRING(write-bytes.unit, evattr_write_bytes_unit, "MB");
> +PMU_EVENT_ATTR_STRING(write-bytes.scale, evattr_write_bytes_scale, "0.000001");
> +
> +struct mmdc_pmu
> +{
> + struct pmu pmu;
> + void __iomem *mmdc_base;
> +};
> +
> +static struct attribute *events_attrs[] = {
> + &evattr_total_cycles.attr.attr,
> + &evattr_busy_cycles.attr.attr,
> + &evattr_read_accesses.attr.attr,
> + &evattr_write_accesses.attr.attr,
> + &evattr_read_bytes.attr.attr,
> + &evattr_read_bytes_unit.attr.attr,
> + &evattr_read_bytes_scale.attr.attr,
> + &evattr_write_bytes.attr.attr,
> + &evattr_write_bytes_unit.attr.attr,
> + &evattr_write_bytes_scale.attr.attr,
> + NULL,
> +};
> +
> +PMU_FORMAT_ATTR(event, "config:0-63");
> +static struct attribute *format_attrs[] = {
> + &format_attr_event.attr,
> + NULL,
> +};
> +
> +static struct attribute_group format_attr_group = {
> + .name = "format",
> + .attrs = format_attrs,
> +};
> +
> +static struct attribute_group events_attr_group = {
> + .name = "events",
> + .attrs = events_attrs,
> +};
> +
> +static const struct attribute_group * attr_groups[] = {
> + &events_attr_group,
> + &format_attr_group,
> + NULL,
> +};
> +
> +static inline u64 mmdc_read_counter(struct perf_event *event)
> +{
> + unsigned int val;
> + u64 ret;
> + int cfg = (int) event->attr.config;
> + struct mmdc_pmu *pmu_mmdc = to_mmdc_pmu(event->pmu);
> + void __iomem *mmdc_base, *reg;
> +
> + mmdc_base = pmu_mmdc->mmdc_base;
> +
> + writel_relaxed(PRF_FRZ, mmdc_base + MMDC_MADPCR0);
> +
> + 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 -1;
> + }
> + val = readl_relaxed(reg);
> + writel_relaxed(DBG_EN, mmdc_base + MMDC_MADPCR0);
> + ret = val;
> + return ret;
> +}
> +
> +static void mmdc_enable_profiling(struct perf_event *event)
> +{
> + 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_relaxed(CYC_OVF | DBG_RST, reg);
> + writel_relaxed(DBG_EN, reg);
> +}
> +
> +static int mmdc_event_init(struct perf_event *event)
> +{
> + u64 val;
> + if (event->attr.type != event->pmu->type)
> + return -ENOENT;
> + mmdc_enable_profiling(event);
> + val = mmdc_read_counter(event);
> + local64_set(&event->hw.prev_count, val);
> + return 0;
> +}
> +
> +static void mmdc_event_update(struct perf_event * event)
> +{
> + u64 val;
> + val = mmdc_read_counter(event);
> + local64_set(&event->count, val);
> +}
> +
> +static void mmdc_event_start(struct perf_event *event, int flags)
> +{
> + mmdc_event_update(event);
> +}
> +
> +static int mmdc_event_add(struct perf_event *event, int flags)
> +{
> + if (flags & PERF_EF_START)
> + mmdc_event_start(event, flags);
> + return 0;
> +}
> +
> +static void mmdc_event_stop(struct perf_event *event, int flags)
> +{
> + mmdc_event_update(event);
> +}
> +
> +static void mmdc_event_del(struct perf_event *event, int flags)
> +{
> + mmdc_event_stop(event, PERF_EF_UPDATE);
> +}
> +
> +static void mmdc_pmu_init(struct mmdc_pmu *pmu_mmdc, void __iomem *mmdc_base)
> +{
> + *pmu_mmdc = (struct mmdc_pmu) {
> + .pmu = (struct pmu) {
> + .task_ctx_nr = perf_sw_context,
> + .attr_groups = attr_groups,
> + .event_init = mmdc_event_init,
> + .add = mmdc_event_add,
> + .del = mmdc_event_del,
> + .start = mmdc_event_start,
> + .stop = mmdc_event_stop,
> + .read = mmdc_event_update,
> + .capabilities = PERF_PMU_CAP_NO_INTERRUPT,
> + },
> + .mmdc_base = mmdc_base,
> + };
> +}
> +
> static int imx_mmdc_probe(struct platform_device *pdev)
> {
> struct device_node *np = pdev->dev.of_node;
> void __iomem *mmdc_base, *reg;
> + struct mmdc_pmu *pmu_mmdc;
> u32 val;
> int timeout = 0x400;
>
> @@ -61,7 +249,22 @@ static int imx_mmdc_probe(struct platform_device *pdev)
> __func__);
> return -EBUSY;
> }
> + pmu_mmdc = kzalloc(sizeof(struct mmdc_pmu), GFP_KERNEL);
> + if (!pmu_mmdc) {
> + pr_err("failed to allocate PMU device!\n");
> + return -ENOMEM;
> + }
> + mmdc_pmu_init(pmu_mmdc, mmdc_base);
> + platform_set_drvdata(pdev, pmu_mmdc);
> + perf_pmu_register(&(pmu_mmdc->pmu), "mmdc", -1);
> + return 0;
> +}
>
> +static int imx_mmdc_remove(struct platform_device *pdev)
> +{
> + struct mmdc_pmu *pmu_mmdc = platform_get_drvdata(pdev);
> + perf_pmu_unregister(&pmu_mmdc->pmu);
> + kfree(pmu_mmdc);
> return 0;
> }
>
> @@ -81,6 +284,7 @@ static struct platform_driver imx_mmdc_driver = {
> .of_match_table = imx_mmdc_dt_ids,
> },
> .probe = imx_mmdc_probe,
> + .remove = imx_mmdc_remove,
> };
>
> static int __init imx_mmdc_init(void)
> --
> 2.9.2
>