[v4,1/2] perf: starfive: Add StarLink PMU support
Commit Message
This patch adds support for StarFive's StarLink PMU (Performance
Monitor Unit). StarLink PMU integrates one or more CPU cores with
a shared L3 memory system. The PMU supports overflow interrupt,
up to 16 programmable 64bit event counters, and an independent
64bit cycle counter. StarLink PMU is accessed via MMIO.
Example Perf stat output:
[root@user]# perf stat -a -e /starfive_starlink_pmu/cycles/ \
-e /starfive_starlink_pmu/read_miss/ \
-e /starfive_starlink_pmu/read_hit/ \
-e /starfive_starlink_pmu/release_request/ \
-e /starfive_starlink_pmu/write_hit/ \
-e /starfive_starlink_pmu/write_miss/ \
-e /starfive_starlink_pmu/write_request/ \
-e /starfive_starlink_pmu/writeback/ \
-e /starfive_starlink_pmu/read_request/ \
-- openssl speed rsa2048
Doing 2048 bits private rsa's for 10s: 5 2048 bits private RSA's in
2.84s
Doing 2048 bits public rsa's for 10s: 169 2048 bits public RSA's in
2.42s
version: 3.0.11
built on: Tue Sep 19 13:02:31 2023 UTC
options: bn(64,64)
CPUINFO: N/A
sign verify sign/s verify/s
rsa 2048 bits 0.568000s 0.014320s 1.8 69.8
/////////
Performance counter stats for 'system wide':
649991998 starfive_starlink_pmu/cycles/
1009690 starfive_starlink_pmu/read_miss/
1079750 starfive_starlink_pmu/read_hit/
2089405 starfive_starlink_pmu/release_request/
129 starfive_starlink_pmu/write_hit/
70 starfive_starlink_pmu/write_miss/
194 starfive_starlink_pmu/write_request/
150080 starfive_starlink_pmu/writeback/
2089423 starfive_starlink_pmu/read_request/
27.062755678 seconds time elapsed
Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
---
drivers/perf/Kconfig | 9 +
drivers/perf/Makefile | 1 +
drivers/perf/starfive_starlink_pmu.c | 654 +++++++++++++++++++++++++++
include/linux/cpuhotplug.h | 1 +
4 files changed, 665 insertions(+)
create mode 100644 drivers/perf/starfive_starlink_pmu.c
Comments
On Fri, 17 Nov 2023 00:23:29 +0800
Ji Sheng Teoh <jisheng.teoh@starfivetech.com> wrote:
> This patch adds support for StarFive's StarLink PMU (Performance
> Monitor Unit). StarLink PMU integrates one or more CPU cores with
> a shared L3 memory system. The PMU supports overflow interrupt,
> up to 16 programmable 64bit event counters, and an independent
> 64bit cycle counter. StarLink PMU is accessed via MMIO.
>
> Example Perf stat output:
> [root@user]# perf stat -a -e /starfive_starlink_pmu/cycles/ \
> -e /starfive_starlink_pmu/read_miss/ \
> -e /starfive_starlink_pmu/read_hit/ \
> -e /starfive_starlink_pmu/release_request/ \
> -e /starfive_starlink_pmu/write_hit/ \
> -e /starfive_starlink_pmu/write_miss/ \
> -e /starfive_starlink_pmu/write_request/ \
> -e /starfive_starlink_pmu/writeback/ \
> -e /starfive_starlink_pmu/read_request/ \
> -- openssl speed rsa2048
> Doing 2048 bits private rsa's for 10s: 5 2048 bits private RSA's in
> 2.84s
> Doing 2048 bits public rsa's for 10s: 169 2048 bits public RSA's in
> 2.42s
> version: 3.0.11
> built on: Tue Sep 19 13:02:31 2023 UTC
> options: bn(64,64)
> CPUINFO: N/A
> sign verify sign/s verify/s
> rsa 2048 bits 0.568000s 0.014320s 1.8 69.8
> /////////
> Performance counter stats for 'system wide':
>
> 649991998 starfive_starlink_pmu/cycles/
> 1009690 starfive_starlink_pmu/read_miss/
> 1079750 starfive_starlink_pmu/read_hit/
> 2089405 starfive_starlink_pmu/release_request/
> 129 starfive_starlink_pmu/write_hit/
> 70 starfive_starlink_pmu/write_miss/
> 194 starfive_starlink_pmu/write_request/
> 150080 starfive_starlink_pmu/writeback/
> 2089423 starfive_starlink_pmu/read_request/
>
> 27.062755678 seconds time elapsed
>
> Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
Hi. Some drive by comments inline.
Mostly concern being consistent with error handling.
Documentation needed.
Documentation/admin-guide/perf
Note I've not looked at perf state machine as would need to remind myself
how that stuff works. So this is all generic driver handling stuff rather
than perf specific.
Thanks,
Jonathan
> ---
> diff --git a/drivers/perf/starfive_starlink_pmu.c b/drivers/perf/starfive_starlink_pmu.c
> new file mode 100644
> index 000000000000..272896ab1ade
> --- /dev/null
> +++ b/drivers/perf/starfive_starlink_pmu.c
> @@ -0,0 +1,654 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * StarFive's StarLink PMU driver
> + *
> + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> + *
> + * Author: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> + *
> + */
> +
> +#define STARLINK_PMU_PDEV_NAME "starfive_starlink_pmu"
> +#define pr_fmt(fmt) STARLINK_PMU_PDEV_NAME ": " fmt
> +
> +#include <linux/bitmap.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
Why? Probably want mod_devicetable.h
> +#include <linux/perf_event.h>
> +#include <linux/platform_device.h>
> +#include <linux/sysfs.h>
> +
> +#define STARLINK_PMU_MAX_COUNTERS 64
> +#define STARLINK_PMU_NUM_COUNTERS 16
> +#define STARLINK_PMU_IDX_CYCLE_COUNTER 63
> +
> +#define STARLINK_PMU_EVENT_SELECT 0x060
> +#define STARLINK_PMU_EVENT_COUNTER 0x160
> +#define STARLINK_PMU_COUNTER_MASK GENMASK_ULL(63, 0)
> +#define STARLINK_PMU_CYCLE_COUNTER 0x058
> +
> +#define STARLINK_PMU_CONTROL 0x040
> +#define STARLINK_PMU_GLOBAL_ENABLE BIT(0)
> +
> +#define STARLINK_PMU_INTERRUPT_ENABLE 0x050
> +#define STARLINK_PMU_COUNTER_OVERFLOW_STATUS 0x048
> +#define STARLINK_PMU_CYCLE_OVERFLOW_MASK BIT(63)
> +
> +#define CYCLES 0x058
Prefix these. Highly likely to have namespace clashes.
STARLINK_CYCLES etc
> +#define CACHE_READ_REQUEST 0x04000701
> +#define CACHE_WRITE_REQUEST 0x03000001
> +#define CACHE_RELEASE_REQUEST 0x0003e001
> +#define CACHE_READ_HIT 0x00901202
> +#define CACHE_READ_MISS 0x04008002
> +#define CACHE_WRITE_HIT 0x006c0002
> +#define CACHE_WRITE_MISS 0x03000002
> +#define CACHE_WRITEBACK 0x00000403
> +
> +#define to_starlink_pmu(p) (container_of(p, struct starlink_pmu, pmu))
> +
> +#define STARLINK_FORMAT_ATTR(_name, _config) \
> + (&((struct dev_ext_attribute[]) { \
> + { .attr = __ATTR(_name, 0444, starlink_pmu_sysfs_format_show, NULL), \
> + .var = (void *)_config, } \
> + })[0].attr.attr)
> +
> +#define STARLINK_EVENT_ATTR(_name, _id) \
> + PMU_EVENT_ATTR_ID(_name, starlink_pmu_sysfs_event_show, _id)
> +
> +#define BIT_IS_SET(nr, bit) (((nr) >> (bit)) & 0x1)
Not sure this macro is worth having. Mostly used as boolean, so
nr & BIT(bit) inline would do the job.
> +
> +struct starlink_hw_events {
> + struct perf_event *events[STARLINK_PMU_MAX_COUNTERS];
> + DECLARE_BITMAP(used_mask, STARLINK_PMU_MAX_COUNTERS);
> +};
> +
> +struct starlink_pmu {
> + struct pmu pmu;
> + struct starlink_hw_events __percpu *hw_events;
> + struct hlist_node node;
> + struct notifier_block starlink_pmu_pm_nb;
> + void __iomem *pmu_base;
> + cpumask_t cpumask;
> + int irq;
> +};
> +
> +/* Formats Attr */
> +static ssize_t
> +starlink_pmu_sysfs_format_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct dev_ext_attribute *eattr = container_of(attr,
> + struct dev_ext_attribute, attr);
> +
> + return sysfs_emit(buf, "%s\n", (char *)eattr->var);
> +}
> +
> +static struct attribute *starlink_pmu_format_attrs[] = {
> + STARLINK_FORMAT_ATTR(event, "config:0-31"),
> + NULL,
As below.
> +};
> +
> +static const struct attribute_group starlink_pmu_format_attr_group = {
> + .name = "format",
> + .attrs = starlink_pmu_format_attrs,
> +};
> +
> +/* Events Attr */
These comments don't really add much given that's easy to see from code.
It's rare that 'structure' comments describing where things are in code
are actually useful in kernel drivers. They tend to be there in example
code to indicate what is needed, but don't keep them!
> +static ssize_t
> +starlink_pmu_sysfs_event_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct perf_pmu_events_attr *eattr = container_of(attr,
> + struct perf_pmu_events_attr, attr);
> +
> + return sysfs_emit(buf, "event=0x%02llx\n", eattr->id);
> +}
> +
> +static struct attribute *starlink_pmu_event_attrs[] = {
> + STARLINK_EVENT_ATTR(cycles, CYCLES),
> + STARLINK_EVENT_ATTR(read_request, CACHE_READ_REQUEST),
> + STARLINK_EVENT_ATTR(write_request, CACHE_WRITE_REQUEST),
> + STARLINK_EVENT_ATTR(release_request, CACHE_RELEASE_REQUEST),
> + STARLINK_EVENT_ATTR(read_hit, CACHE_READ_HIT),
> + STARLINK_EVENT_ATTR(read_miss, CACHE_READ_MISS),
> + STARLINK_EVENT_ATTR(write_hit, CACHE_WRITE_HIT),
> + STARLINK_EVENT_ATTR(write_miss, CACHE_WRITE_MISS),
> + STARLINK_EVENT_ATTR(writeback, CACHE_WRITEBACK),
> + NULL,
As below.
> +};
> +
> +static const struct attribute_group starlink_pmu_events_attr_group = {
> + .name = "events",
> + .attrs = starlink_pmu_event_attrs,
> +};
> +
> +/* Cpumask Attr */
> +static ssize_t
> +cpumask_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct starlink_pmu *starlink_pmu = to_starlink_pmu(dev_get_drvdata(dev));
> +
> + return cpumap_print_to_pagebuf(true, buf, &starlink_pmu->cpumask);
> +}
> +
> +static DEVICE_ATTR_RO(cpumask);
> +
> +static struct attribute *starlink_pmu_cpumask_attrs[] = {
> + &dev_attr_cpumask.attr,
> + NULL,
As below.
> +};
> +
> +static const struct attribute_group starlink_pmu_cpumask_attr_group = {
> + .attrs = starlink_pmu_cpumask_attrs,
> +};
> +
> +static const struct attribute_group *starlink_pmu_attr_groups[] = {
> + &starlink_pmu_format_attr_group,
> + &starlink_pmu_events_attr_group,
> + &starlink_pmu_cpumask_attr_group,
> + NULL,
No comma after NULL terminator as we can't add anything there anyway.
> +};
> +
> +static void starlink_pmu_counter_stop(struct perf_event *event,
> + struct starlink_pmu *starlink_pmu)
> +{
> + struct hw_perf_event *hwc = &event->hw;
> + int idx = event->hw.idx;
> + u64 val;
> +
> + /* Stop counter */
Pretty obvious that clearing global enable stops the counter.
Perhaps review comments and remove any that are obvious from the code.
Such comments add little value and can be a maintenance problem.
> + val = readq(starlink_pmu->pmu_base + STARLINK_PMU_CONTROL);
> + val &= ~STARLINK_PMU_GLOBAL_ENABLE;
> + writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_CONTROL);
> +
> + /* Disable counter overflow interrupt */
> + val = readq(starlink_pmu->pmu_base + STARLINK_PMU_INTERRUPT_ENABLE);
> + if (hwc->config == CYCLES)
> + val &= ~STARLINK_PMU_CYCLE_OVERFLOW_MASK;
> + else
> + val &= ~(1 << idx);
> +
> + writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_INTERRUPT_ENABLE);
> +}
> +static bool starlink_pmu_validate_event_group(struct perf_event *event)
> +{
> + struct perf_event *leader = event->group_leader;
> + struct perf_event *sibling;
> + int counter = 1;
> +
> + /*
> + * Ensure hardware events in the group are on the same PMU,
> + * software events are acceptable.
> + */
> + if (event->group_leader->pmu != event->pmu &&
> + !is_software_event(event->group_leader))
> + return false;
> +
> + for_each_sibling_event(sibling, leader) {
> + if (sibling->pmu != event->pmu && !is_software_event(sibling))
> + return false;
> +
> + counter += 1;
counter++;
> + }
> + /*
> + * Limit the number of requested counter to
> + * counter available on the HW.
> + */
> + return counter <= STARLINK_PMU_NUM_COUNTERS;
> +}
> +
...
> +
> +static irqreturn_t starlink_pmu_handle_irq(int irq_num, void *data)
> +{
> + struct starlink_pmu *starlink_pmu = data;
> + struct starlink_hw_events *hw_events =
> + this_cpu_ptr(starlink_pmu->hw_events);
Odd alignment. I'd put it one tab more than struct.
> + bool handled = false;
> + int idx;
> + u64 overflow_status;
> +
> + for (idx = 0; idx < STARLINK_PMU_MAX_COUNTERS; idx++) {
> + struct perf_event *event = hw_events->events[idx];
> +
> + overflow_status = readq(starlink_pmu->pmu_base +
> + STARLINK_PMU_COUNTER_OVERFLOW_STATUS);
> + if (!BIT_IS_SET(overflow_status, idx))
> + continue;
> +
> + /* Clear event counter overflow interrupt */
> + writeq(1 << idx, starlink_pmu->pmu_base +
> + STARLINK_PMU_COUNTER_OVERFLOW_STATUS);
> +
> + if (!event)
> + continue;
If you get here and !event. Is it a bug, or something valid?
Maybe a comment if it's valid. Otherwise an error print might make sense.
> +
> + starlink_pmu_update(event);
> + starlink_pmu_set_event_period(event);
> + handled = true;
> + }
> + return IRQ_RETVAL(handled);
> +}
> +
> +static int starlink_setup_irqs(struct starlink_pmu *starlink_pmu,
> + struct platform_device *pdev)
> +{
> + int ret, irq;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return -EINVAL;
> +
> + ret = devm_request_irq(&pdev->dev, irq, starlink_pmu_handle_irq,
> + 0, STARLINK_PMU_PDEV_NAME, starlink_pmu);
> + if (ret) {
> + dev_warn(&pdev->dev, "Failed to request IRQ %d\n", irq);
> + return ret;
return dev_err_probe(...)
> + }
> +
> + starlink_pmu->irq = irq;
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_CPU_PM
> +static int starlink_pmu_pm_notify(struct notifier_block *b,
> + unsigned long cmd, void *v)
> +{
> + struct starlink_pmu *starlink_pmu = container_of(b, struct starlink_pmu,
> + starlink_pmu_pm_nb);
Compiler can probably figure out this isn't used. But if not
if (!IS_ENABLED(CONFIG_CPU_PM))
return 0;
will allow the compiler to definitely remove the code.
> + struct starlink_hw_events *hw_events =
> + this_cpu_ptr(starlink_pmu->hw_events);
> + int enabled = bitmap_weight(hw_events->used_mask,
> + STARLINK_PMU_MAX_COUNTERS);
> + struct perf_event *event;
> + int idx;
> +
> + if (!enabled)
> + return NOTIFY_OK;
> +
> + for (idx = 0; idx < STARLINK_PMU_MAX_COUNTERS; idx++) {
> + event = hw_events->events[idx];
> + if (!event)
> + continue;
> +
> + switch (cmd) {
> + case CPU_PM_ENTER:
> + /* Stop and update the counter */
> + starlink_pmu_stop(event, PERF_EF_UPDATE);
> + break;
> + case CPU_PM_EXIT:
> + case CPU_PM_ENTER_FAILED:
> + /* Restore and enable the counter */
> + starlink_pmu_start(event, PERF_EF_RELOAD);
> + break;
> + default:
> + break;
> + }
> + }
> +
> + return NOTIFY_OK;
> +}
> +
> +static int starlink_pmu_pm_register(struct starlink_pmu *starlink_pmu)
> +{
> + starlink_pmu->starlink_pmu_pm_nb.notifier_call = starlink_pmu_pm_notify;
> + return cpu_pm_register_notifier(&starlink_pmu->starlink_pmu_pm_nb);
Stubbed out as below.
> +}
> +
> +static void starlink_pmu_pm_unregister(struct starlink_pmu *starlink_pmu)
> +{
> + cpu_pm_unregister_notifier(&starlink_pmu->starlink_pmu_pm_nb);
stubbed out in header so no need to protect with ifdef.
Compiler will probably remove it anyway.
> +}
> +#else
> +static inline int
> +starlink_pmu_pm_register(struct starlink_pmu *starlink_pmu) { return 0; }
> +static inline void
> +starlink_pmu_pm_unregister(struct starlink_pmu *starlink_pmu) { }
> +#endif
> +
> +static void starlink_pmu_destroy(struct starlink_pmu *starlink_pmu)
> +{
> + starlink_pmu_pm_unregister(starlink_pmu);
> + cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
> + &starlink_pmu->node);
> +}
> +
> +static int starlink_pmu_probe(struct platform_device *pdev)
> +{
> + struct starlink_pmu *starlink_pmu;
> + struct starlink_hw_events *hw_events;
> + struct resource *res;
> + int cpuid, i, ret;
> +
> + starlink_pmu = devm_kzalloc(&pdev->dev, sizeof(*starlink_pmu), GFP_KERNEL);
> + if (!starlink_pmu)
> + return -ENOMEM;
> +
> + starlink_pmu->pmu_base =
> + devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> + if (IS_ERR(starlink_pmu->pmu_base))
> + return PTR_ERR(starlink_pmu->pmu_base);
> +
> + ret = starlink_setup_irqs(starlink_pmu, pdev);
Handle ret You are printing a warning so I'd assume it's a failure to probe
case, not something ignored.
> +
> + ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
> + &starlink_pmu->node);
> + if (ret)
Not dropped in error paths.
> + return ret;
> +
> + ret = starlink_pmu_pm_register(starlink_pmu);
> + if (ret)
> + starlink_pmu_destroy(starlink_pmu);
This calls starlink_pmu_pm_unregister()
That should not be necessary as every function should be designed to have no side effects
on error return.
> +
> + starlink_pmu->hw_events = alloc_percpu_gfp(struct starlink_hw_events,
> + GFP_KERNEL);
> + if (!starlink_pmu->hw_events) {
> + pr_info("Failed to allocate per-cpu PMU data.\n");
> + kfree(starlink_pmu);
Inconsistent error handling. Before and aftre this you call starlink_pmu_destroy()
but not here.
> + return -ENOMEM;
> + }
> +
> + for_each_possible_cpu(cpuid) {
> + hw_events = per_cpu_ptr(starlink_pmu->hw_events, cpuid);
> + for (i = 0; i < STARLINK_PMU_MAX_COUNTERS; i++)
> + hw_events->events[i] = NULL;
> + }
> +
> + starlink_pmu->pmu = (struct pmu) {
> + .task_ctx_nr = perf_invalid_context,
> + .event_init = starlink_pmu_event_init,
> + .add = starlink_pmu_add,
> + .del = starlink_pmu_del,
> + .start = starlink_pmu_start,
> + .stop = starlink_pmu_stop,
> + .read = starlink_pmu_update,
> + .attr_groups = starlink_pmu_attr_groups,
> + };
> +
> + ret = perf_pmu_register(&starlink_pmu->pmu, STARLINK_PMU_PDEV_NAME, -1);
> + if (ret)
> + starlink_pmu_destroy(starlink_pmu);
> +
> + dev_info(&pdev->dev, "Registered StarFive's StarLink PMU\n");
Noise. Don't print to the log when there are many other ways to find this out.
> +
> + return ret;
> +}
> +
> +static const struct of_device_id starlink_pmu_of_match[] = {
> + { .compatible = "starfive,jh8100-starlink-pmu", },
> + {},
No need for comma after a 'terminator' as nothing can come after it.
> +};
> +MODULE_DEVICE_TABLE(of, starlink_pmu_of_match);
> +device_initcall(starlink_pmu_init);
> diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> index d305db70674b..6d9eb70c13d4 100644
> --- a/include/linux/cpuhotplug.h
> +++ b/include/linux/cpuhotplug.h
> @@ -219,6 +219,7 @@ enum cpuhp_state {
> CPUHP_AP_PERF_X86_CQM_ONLINE,
> CPUHP_AP_PERF_X86_CSTATE_ONLINE,
> CPUHP_AP_PERF_X86_IDXD_ONLINE,
> + CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
Can you use CPUHP_AP_ONLINE_DYN?
Moves it a bit later in the sequence but it often works for perf drivers.
> CPUHP_AP_PERF_S390_CF_ONLINE,
> CPUHP_AP_PERF_S390_SF_ONLINE,
> CPUHP_AP_PERF_ARM_CCI_ONLINE,
On Wed, 29 Nov 2023 11:02:38 +0000
Jonathan Cameron <Jonathan.Cameron@Huawei.com> wrote:
> On Fri, 17 Nov 2023 00:23:29 +0800
> Ji Sheng Teoh <jisheng.teoh@starfivetech.com> wrote:
>
> > This patch adds support for StarFive's StarLink PMU (Performance
> > Monitor Unit). StarLink PMU integrates one or more CPU cores with
> > a shared L3 memory system. The PMU supports overflow interrupt,
> > up to 16 programmable 64bit event counters, and an independent
> > 64bit cycle counter. StarLink PMU is accessed via MMIO.
> >
> > Example Perf stat output:
> > [root@user]# perf stat -a -e /starfive_starlink_pmu/cycles/ \
> > -e /starfive_starlink_pmu/read_miss/ \
> > -e /starfive_starlink_pmu/read_hit/ \
> > -e /starfive_starlink_pmu/release_request/ \
> > -e /starfive_starlink_pmu/write_hit/ \
> > -e /starfive_starlink_pmu/write_miss/ \
> > -e /starfive_starlink_pmu/write_request/ \
> > -e /starfive_starlink_pmu/writeback/ \
> > -e /starfive_starlink_pmu/read_request/ \
> > -- openssl speed rsa2048
> > Doing 2048 bits private rsa's for 10s: 5 2048 bits private RSA's in
> > 2.84s
> > Doing 2048 bits public rsa's for 10s: 169 2048 bits public RSA's in
> > 2.42s
> > version: 3.0.11
> > built on: Tue Sep 19 13:02:31 2023 UTC
> > options: bn(64,64)
> > CPUINFO: N/A
> > sign verify sign/s verify/s
> > rsa 2048 bits 0.568000s 0.014320s 1.8 69.8
> > /////////
> > Performance counter stats for 'system wide':
> >
> > 649991998 starfive_starlink_pmu/cycles/
> > 1009690 starfive_starlink_pmu/read_miss/
> > 1079750 starfive_starlink_pmu/read_hit/
> > 2089405 starfive_starlink_pmu/release_request/
> > 129 starfive_starlink_pmu/write_hit/
> > 70 starfive_starlink_pmu/write_miss/
> > 194 starfive_starlink_pmu/write_request/
> > 150080 starfive_starlink_pmu/writeback/
> > 2089423 starfive_starlink_pmu/read_request/
> >
> > 27.062755678 seconds time elapsed
> >
> > Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> Hi. Some drive by comments inline.
>
> Mostly concern being consistent with error handling.
>
> Documentation needed.
> Documentation/admin-guide/perf
Sure, will include it.
>
> Note I've not looked at perf state machine as would need to remind
> myself how that stuff works. So this is all generic driver handling
> stuff rather than perf specific.
>
> Thanks,
>
> Jonathan
>
> > ---
> > diff --git a/drivers/perf/starfive_starlink_pmu.c
> > b/drivers/perf/starfive_starlink_pmu.c new file mode 100644
> > index 000000000000..272896ab1ade
> > --- /dev/null
> > +++ b/drivers/perf/starfive_starlink_pmu.c
> > @@ -0,0 +1,654 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * StarFive's StarLink PMU driver
> > + *
> > + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> > + *
> > + * Author: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> > + *
> > + */
> > +
> > +#define STARLINK_PMU_PDEV_NAME "starfive_starlink_pmu"
> > +#define pr_fmt(fmt) STARLINK_PMU_PDEV_NAME ": " fmt
> > +
> > +#include <linux/bitmap.h>
> > +#include <linux/cpu_pm.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
>
> Why? Probably want mod_devicetable.h
Ok, that is a better option. Thanks
>
> > +#include <linux/perf_event.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/sysfs.h>
> > +
> > +#define STARLINK_PMU_MAX_COUNTERS 64
> > +#define STARLINK_PMU_NUM_COUNTERS 16
> > +#define STARLINK_PMU_IDX_CYCLE_COUNTER 63
> > +
> > +#define STARLINK_PMU_EVENT_SELECT 0x060
> > +#define STARLINK_PMU_EVENT_COUNTER 0x160
> > +#define STARLINK_PMU_COUNTER_MASK
> > GENMASK_ULL(63, 0) +#define STARLINK_PMU_CYCLE_COUNTER
> > 0x058 +
> > +#define STARLINK_PMU_CONTROL 0x040
> > +#define STARLINK_PMU_GLOBAL_ENABLE BIT(0)
> > +
> > +#define STARLINK_PMU_INTERRUPT_ENABLE 0x050
> > +#define STARLINK_PMU_COUNTER_OVERFLOW_STATUS 0x048
> > +#define STARLINK_PMU_CYCLE_OVERFLOW_MASK BIT(63)
> > +
> > +#define CYCLES 0x058
>
> Prefix these. Highly likely to have namespace clashes.
> STARLINK_CYCLES etc
Ok, that makes sense. Will make the change.
>
> > +#define CACHE_READ_REQUEST 0x04000701
> > +#define CACHE_WRITE_REQUEST 0x03000001
> > +#define CACHE_RELEASE_REQUEST 0x0003e001
> > +#define CACHE_READ_HIT 0x00901202
> > +#define CACHE_READ_MISS 0x04008002
> > +#define CACHE_WRITE_HIT 0x006c0002
> > +#define CACHE_WRITE_MISS 0x03000002
> > +#define CACHE_WRITEBACK 0x00000403
> > +
> > +#define to_starlink_pmu(p) (container_of(p, struct starlink_pmu,
> > pmu)) +
> > +#define STARLINK_FORMAT_ATTR(_name, _config)
> > \
> > + (&((struct dev_ext_attribute[]) {
> > \
> > + { .attr = __ATTR(_name, 0444,
> > starlink_pmu_sysfs_format_show, NULL), \
> > + .var = (void *)_config, }
> > \
> > + })[0].attr.attr)
> > +
> > +#define STARLINK_EVENT_ATTR(_name, _id)
> > \
> > + PMU_EVENT_ATTR_ID(_name, starlink_pmu_sysfs_event_show,
> > _id) +
> > +#define BIT_IS_SET(nr, bit) (((nr) >> (bit)) & 0x1)
>
> Not sure this macro is worth having. Mostly used as boolean, so
> nr & BIT(bit) inline would do the job.
>
Ok, will revise it based on your suggestion.
> > +
> > +struct starlink_hw_events {
> > + struct perf_event
> > *events[STARLINK_PMU_MAX_COUNTERS];
> > + DECLARE_BITMAP(used_mask, STARLINK_PMU_MAX_COUNTERS);
> > +};
> > +
> > +struct starlink_pmu {
> > + struct pmu pmu;
> > + struct starlink_hw_events __percpu
> > *hw_events;
> > + struct hlist_node node;
> > + struct notifier_block
> > starlink_pmu_pm_nb;
> > + void __iomem
> > *pmu_base;
> > + cpumask_t cpumask;
> > + int irq;
> > +};
> > +
> > +/* Formats Attr */
> > +static ssize_t
> > +starlink_pmu_sysfs_format_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct dev_ext_attribute *eattr = container_of(attr,
> > + struct
> > dev_ext_attribute, attr); +
> > + return sysfs_emit(buf, "%s\n", (char *)eattr->var);
> > +}
> > +
> > +static struct attribute *starlink_pmu_format_attrs[] = {
> > + STARLINK_FORMAT_ATTR(event, "config:0-31"),
> > + NULL,
> As below.
>
> > +};
> > +
> > +static const struct attribute_group starlink_pmu_format_attr_group
> > = {
> > + .name = "format",
> > + .attrs = starlink_pmu_format_attrs,
> > +};
> > +
> > +/* Events Attr */
>
> These comments don't really add much given that's easy to see from
> code. It's rare that 'structure' comments describing where things are
> in code are actually useful in kernel drivers. They tend to be there
> in example code to indicate what is needed, but don't keep them!
>
Ok, will drop them.
>
> > +static ssize_t
> > +starlink_pmu_sysfs_event_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct perf_pmu_events_attr *eattr = container_of(attr,
> > + struct
> > perf_pmu_events_attr, attr); +
> > + return sysfs_emit(buf, "event=0x%02llx\n", eattr->id);
> > +}
> > +
> > +static struct attribute *starlink_pmu_event_attrs[] = {
> > + STARLINK_EVENT_ATTR(cycles, CYCLES),
> > + STARLINK_EVENT_ATTR(read_request, CACHE_READ_REQUEST),
> > + STARLINK_EVENT_ATTR(write_request, CACHE_WRITE_REQUEST),
> > + STARLINK_EVENT_ATTR(release_request,
> > CACHE_RELEASE_REQUEST),
> > + STARLINK_EVENT_ATTR(read_hit, CACHE_READ_HIT),
> > + STARLINK_EVENT_ATTR(read_miss, CACHE_READ_MISS),
> > + STARLINK_EVENT_ATTR(write_hit, CACHE_WRITE_HIT),
> > + STARLINK_EVENT_ATTR(write_miss, CACHE_WRITE_MISS),
> > + STARLINK_EVENT_ATTR(writeback, CACHE_WRITEBACK),
> > + NULL,
>
> As below.
>
> > +};
> > +
> > +static const struct attribute_group starlink_pmu_events_attr_group
> > = {
> > + .name = "events",
> > + .attrs = starlink_pmu_event_attrs,
> > +};
> > +
> > +/* Cpumask Attr */
> > +static ssize_t
> > +cpumask_show(struct device *dev, struct device_attribute *attr,
> > char *buf) +{
> > + struct starlink_pmu *starlink_pmu =
> > to_starlink_pmu(dev_get_drvdata(dev)); +
> > + return cpumap_print_to_pagebuf(true, buf,
> > &starlink_pmu->cpumask); +}
> > +
> > +static DEVICE_ATTR_RO(cpumask);
> > +
> > +static struct attribute *starlink_pmu_cpumask_attrs[] = {
> > + &dev_attr_cpumask.attr,
> > + NULL,
>
> As below.
>
> > +};
> > +
> > +static const struct attribute_group
> > starlink_pmu_cpumask_attr_group = {
> > + .attrs = starlink_pmu_cpumask_attrs,
> > +};
> > +
> > +static const struct attribute_group *starlink_pmu_attr_groups[] = {
> > + &starlink_pmu_format_attr_group,
> > + &starlink_pmu_events_attr_group,
> > + &starlink_pmu_cpumask_attr_group,
> > + NULL,
>
> No comma after NULL terminator as we can't add anything there anyway.
>
Ok, will drop them.
> > +};
>
>
> > +
> > +static void starlink_pmu_counter_stop(struct perf_event *event,
> > + struct starlink_pmu
> > *starlink_pmu) +{
> > + struct hw_perf_event *hwc = &event->hw;
> > + int idx = event->hw.idx;
> > + u64 val;
> > +
> > + /* Stop counter */
>
> Pretty obvious that clearing global enable stops the counter.
> Perhaps review comments and remove any that are obvious from the code.
> Such comments add little value and can be a maintenance problem.
>
Ok, will review again and drop those comments that are obvious.
> > + val = readq(starlink_pmu->pmu_base + STARLINK_PMU_CONTROL);
> > + val &= ~STARLINK_PMU_GLOBAL_ENABLE;
> > + writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_CONTROL);
> > +
> > + /* Disable counter overflow interrupt */
> > + val = readq(starlink_pmu->pmu_base +
> > STARLINK_PMU_INTERRUPT_ENABLE);
> > + if (hwc->config == CYCLES)
> > + val &= ~STARLINK_PMU_CYCLE_OVERFLOW_MASK;
> > + else
> > + val &= ~(1 << idx);
> > +
> > + writeq(val, starlink_pmu->pmu_base +
> > STARLINK_PMU_INTERRUPT_ENABLE); +}
>
>
>
> > +static bool starlink_pmu_validate_event_group(struct perf_event
> > *event) +{
> > + struct perf_event *leader = event->group_leader;
> > + struct perf_event *sibling;
> > + int counter = 1;
> > +
> > + /*
> > + * Ensure hardware events in the group are on the same PMU,
> > + * software events are acceptable.
> > + */
> > + if (event->group_leader->pmu != event->pmu &&
> > + !is_software_event(event->group_leader))
> > + return false;
> > +
> > + for_each_sibling_event(sibling, leader) {
> > + if (sibling->pmu != event->pmu &&
> > !is_software_event(sibling))
> > + return false;
> > +
> > + counter += 1;
>
> counter++;
Ok, will amend.
>
> > + }
> > + /*
> > + * Limit the number of requested counter to
> > + * counter available on the HW.
> > + */
> > + return counter <= STARLINK_PMU_NUM_COUNTERS;
> > +}
> > +
>
> ...
>
> > +
> > +static irqreturn_t starlink_pmu_handle_irq(int irq_num, void *data)
> > +{
> > + struct starlink_pmu *starlink_pmu = data;
> > + struct starlink_hw_events *hw_events =
> > +
> > this_cpu_ptr(starlink_pmu->hw_events);
>
> Odd alignment. I'd put it one tab more than struct.
Ok, will realign them.
>
> > + bool handled = false;
> > + int idx;
> > + u64 overflow_status;
> > +
> > + for (idx = 0; idx < STARLINK_PMU_MAX_COUNTERS; idx++) {
> > + struct perf_event *event = hw_events->events[idx];
> > +
> > + overflow_status = readq(starlink_pmu->pmu_base +
> > +
> > STARLINK_PMU_COUNTER_OVERFLOW_STATUS);
> > + if (!BIT_IS_SET(overflow_status, idx))
> > + continue;
> > +
> > + /* Clear event counter overflow interrupt */
> > + writeq(1 << idx, starlink_pmu->pmu_base +
> > + STARLINK_PMU_COUNTER_OVERFLOW_STATUS);
> > +
> > + if (!event)
> > + continue;
> If you get here and !event. Is it a bug, or something valid?
> Maybe a comment if it's valid. Otherwise an error print might make
> sense.
>
They should have appear earlier right before reading the overflow
status, and continue next bit in the case where event is not valid.
Will fix it.
> > +
> > + starlink_pmu_update(event);
> > + starlink_pmu_set_event_period(event);
> > + handled = true;
> > + }
> > + return IRQ_RETVAL(handled);
> > +}
> > +
> > +static int starlink_setup_irqs(struct starlink_pmu *starlink_pmu,
> > + struct platform_device *pdev)
> > +{
> > + int ret, irq;
> > +
> > + irq = platform_get_irq(pdev, 0);
> > + if (irq < 0)
> > + return -EINVAL;
> > +
> > + ret = devm_request_irq(&pdev->dev, irq,
> > starlink_pmu_handle_irq,
> > + 0, STARLINK_PMU_PDEV_NAME,
> > starlink_pmu);
> > + if (ret) {
> > + dev_warn(&pdev->dev, "Failed to request IRQ %d\n",
> > irq);
> > + return ret;
>
> return dev_err_probe(...)
Will pass this ret back to probe() to handle instead.
>
> > + }
> > +
> > + starlink_pmu->irq = irq;
> > +
> > + return 0;
> > +}
> > +
> > +#ifdef CONFIG_CPU_PM
> > +static int starlink_pmu_pm_notify(struct notifier_block *b,
> > + unsigned long cmd, void *v)
> > +{
> > + struct starlink_pmu *starlink_pmu = container_of(b, struct
> > starlink_pmu,
> > +
> > starlink_pmu_pm_nb);
>
> Compiler can probably figure out this isn't used. But if not
> if (!IS_ENABLED(CONFIG_CPU_PM))
> return 0;
>
> will allow the compiler to definitely remove the code.
Good info, thanks for the suggestion. Will use
'if (IS_ENABLED(CONFIG_CPU_PM))' in place of '#ifdef CONFIG_CPU_PM'.
>
> > + struct starlink_hw_events *hw_events =
> > +
> > this_cpu_ptr(starlink_pmu->hw_events);
> > + int enabled = bitmap_weight(hw_events->used_mask,
> > + STARLINK_PMU_MAX_COUNTERS);
> > + struct perf_event *event;
> > + int idx;
> > +
> > + if (!enabled)
> > + return NOTIFY_OK;
> > +
> > + for (idx = 0; idx < STARLINK_PMU_MAX_COUNTERS; idx++) {
> > + event = hw_events->events[idx];
> > + if (!event)
> > + continue;
> > +
> > + switch (cmd) {
> > + case CPU_PM_ENTER:
> > + /* Stop and update the counter */
> > + starlink_pmu_stop(event, PERF_EF_UPDATE);
> > + break;
> > + case CPU_PM_EXIT:
> > + case CPU_PM_ENTER_FAILED:
> > + /* Restore and enable the counter */
> > + starlink_pmu_start(event, PERF_EF_RELOAD);
> > + break;
> > + default:
> > + break;
> > + }
> > + }
> > +
> > + return NOTIFY_OK;
> > +}
> > +
> > +static int starlink_pmu_pm_register(struct starlink_pmu
> > *starlink_pmu) +{
> > + starlink_pmu->starlink_pmu_pm_nb.notifier_call =
> > starlink_pmu_pm_notify;
> > + return
> > cpu_pm_register_notifier(&starlink_pmu->starlink_pmu_pm_nb);
> Stubbed out as below.
>
> > +}
> > +
> > +static void starlink_pmu_pm_unregister(struct starlink_pmu
> > *starlink_pmu) +{
> > +
> > cpu_pm_unregister_notifier(&starlink_pmu->starlink_pmu_pm_nb);
>
> stubbed out in header so no need to protect with ifdef.
> Compiler will probably remove it anyway.
>
Ok, will fix.
> > +}
> > +#else
> > +static inline int
> > +starlink_pmu_pm_register(struct starlink_pmu *starlink_pmu) {
> > return 0; } +static inline void
> > +starlink_pmu_pm_unregister(struct starlink_pmu *starlink_pmu) { }
> > +#endif
> > +
> > +static void starlink_pmu_destroy(struct starlink_pmu *starlink_pmu)
> > +{
> > + starlink_pmu_pm_unregister(starlink_pmu);
> > +
> > cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
> > + &starlink_pmu->node);
> > +}
> > +
> > +static int starlink_pmu_probe(struct platform_device *pdev)
> > +{
> > + struct starlink_pmu *starlink_pmu;
> > + struct starlink_hw_events *hw_events;
> > + struct resource *res;
> > + int cpuid, i, ret;
> > +
> > + starlink_pmu = devm_kzalloc(&pdev->dev,
> > sizeof(*starlink_pmu), GFP_KERNEL);
> > + if (!starlink_pmu)
> > + return -ENOMEM;
> > +
> > + starlink_pmu->pmu_base =
> > +
> > devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> > + if (IS_ERR(starlink_pmu->pmu_base))
> > + return PTR_ERR(starlink_pmu->pmu_base);
> > +
> > + ret = starlink_setup_irqs(starlink_pmu, pdev);
>
> Handle ret You are printing a warning so I'd assume it's a failure
> to probe case, not something ignored.
>
Missed that, will fix it.
>
> > +
> > + ret =
> > cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
> > + &starlink_pmu->node);
> > + if (ret)
>
> Not dropped in error paths.
Ok, will fix it.
>
> > + return ret;
> > +
> > + ret = starlink_pmu_pm_register(starlink_pmu);
> > + if (ret)
> > + starlink_pmu_destroy(starlink_pmu);
>
> This calls starlink_pmu_pm_unregister()
> That should not be necessary as every function should be designed to
> have no side effects on error return.
>
Ok, will fix it.
> > +
> > + starlink_pmu->hw_events = alloc_percpu_gfp(struct
> > starlink_hw_events,
> > + GFP_KERNEL);
> > + if (!starlink_pmu->hw_events) {
> > + pr_info("Failed to allocate per-cpu PMU data.\n");
> > + kfree(starlink_pmu);
>
> Inconsistent error handling. Before and aftre this you call
> starlink_pmu_destroy() but not here.
>
Ok, will rectify it.
> > + return -ENOMEM;
> > + }
> > +
> > + for_each_possible_cpu(cpuid) {
> > + hw_events = per_cpu_ptr(starlink_pmu->hw_events,
> > cpuid);
> > + for (i = 0; i < STARLINK_PMU_MAX_COUNTERS; i++)
> > + hw_events->events[i] = NULL;
> > + }
> > +
> > + starlink_pmu->pmu = (struct pmu) {
> > + .task_ctx_nr = perf_invalid_context,
> > + .event_init = starlink_pmu_event_init,
> > + .add = starlink_pmu_add,
> > + .del = starlink_pmu_del,
> > + .start = starlink_pmu_start,
> > + .stop = starlink_pmu_stop,
> > + .read = starlink_pmu_update,
> > + .attr_groups = starlink_pmu_attr_groups,
> > + };
> > +
> > + ret = perf_pmu_register(&starlink_pmu->pmu,
> > STARLINK_PMU_PDEV_NAME, -1);
> > + if (ret)
> > + starlink_pmu_destroy(starlink_pmu);
> > +
> > + dev_info(&pdev->dev, "Registered StarFive's StarLink
> > PMU\n");
>
> Noise. Don't print to the log when there are many other ways to find
> this out.
>
Ok, will drop it.
> > +
> > + return ret;
> > +}
> > +
> > +static const struct of_device_id starlink_pmu_of_match[] = {
> > + { .compatible = "starfive,jh8100-starlink-pmu", },
> > + {},
>
> No need for comma after a 'terminator' as nothing can come after it.
>
Ok, will drop it.
> > +};
> > +MODULE_DEVICE_TABLE(of, starlink_pmu_of_match);
>
> > +device_initcall(starlink_pmu_init);
> > diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
> > index d305db70674b..6d9eb70c13d4 100644
> > --- a/include/linux/cpuhotplug.h
> > +++ b/include/linux/cpuhotplug.h
> > @@ -219,6 +219,7 @@ enum cpuhp_state {
> > CPUHP_AP_PERF_X86_CQM_ONLINE,
> > CPUHP_AP_PERF_X86_CSTATE_ONLINE,
> > CPUHP_AP_PERF_X86_IDXD_ONLINE,
> > + CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
> Can you use CPUHP_AP_ONLINE_DYN?
>
> Moves it a bit later in the sequence but it often works for perf
> drivers.
>
Yup, that should work as well. Will use CPUHP_AP_ONLINE_DYN instead.
> > CPUHP_AP_PERF_S390_CF_ONLINE,
> > CPUHP_AP_PERF_S390_SF_ONLINE,
> > CPUHP_AP_PERF_ARM_CCI_ONLINE,
>
Thanks for reviewing Jonathan.
Thanks,
Ji Sheng
On Thu, Nov 16, 2023 at 10:24 AM Ji Sheng Teoh
<jisheng.teoh@starfivetech.com> wrote:
>
> This patch adds support for StarFive's StarLink PMU (Performance
> Monitor Unit). StarLink PMU integrates one or more CPU cores with
> a shared L3 memory system. The PMU supports overflow interrupt,
> up to 16 programmable 64bit event counters, and an independent
> 64bit cycle counter. StarLink PMU is accessed via MMIO.
>
> Example Perf stat output:
> [root@user]# perf stat -a -e /starfive_starlink_pmu/cycles/ \
> -e /starfive_starlink_pmu/read_miss/ \
> -e /starfive_starlink_pmu/read_hit/ \
> -e /starfive_starlink_pmu/release_request/ \
> -e /starfive_starlink_pmu/write_hit/ \
> -e /starfive_starlink_pmu/write_miss/ \
> -e /starfive_starlink_pmu/write_request/ \
> -e /starfive_starlink_pmu/writeback/ \
> -e /starfive_starlink_pmu/read_request/ \
> -- openssl speed rsa2048
> Doing 2048 bits private rsa's for 10s: 5 2048 bits private RSA's in
> 2.84s
> Doing 2048 bits public rsa's for 10s: 169 2048 bits public RSA's in
> 2.42s
> version: 3.0.11
> built on: Tue Sep 19 13:02:31 2023 UTC
> options: bn(64,64)
> CPUINFO: N/A
> sign verify sign/s verify/s
> rsa 2048 bits 0.568000s 0.014320s 1.8 69.8
> /////////
> Performance counter stats for 'system wide':
>
> 649991998 starfive_starlink_pmu/cycles/
> 1009690 starfive_starlink_pmu/read_miss/
> 1079750 starfive_starlink_pmu/read_hit/
> 2089405 starfive_starlink_pmu/release_request/
> 129 starfive_starlink_pmu/write_hit/
> 70 starfive_starlink_pmu/write_miss/
> 194 starfive_starlink_pmu/write_request/
> 150080 starfive_starlink_pmu/writeback/
> 2089423 starfive_starlink_pmu/read_request/
>
> 27.062755678 seconds time elapsed
>
> Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> ---
> drivers/perf/Kconfig | 9 +
> drivers/perf/Makefile | 1 +
> drivers/perf/starfive_starlink_pmu.c | 654 +++++++++++++++++++++++++++
> include/linux/cpuhotplug.h | 1 +
> 4 files changed, 665 insertions(+)
> create mode 100644 drivers/perf/starfive_starlink_pmu.c
>
> diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
> index 273d67ecf6d2..41278742ef88 100644
> --- a/drivers/perf/Kconfig
> +++ b/drivers/perf/Kconfig
> @@ -86,6 +86,15 @@ config RISCV_PMU_SBI
> full perf feature support i.e. counter overflow, privilege mode
> filtering, counter configuration.
>
> +config STARFIVE_STARLINK_PMU
> + depends on ARCH_STARFIVE
> + bool "StarFive StarLink PMU"
> + help
> + Provide support for StarLink Performance Monitor Unit.
> + StarLink Performance Monitor Unit integrates one or more cores with
> + an L3 memory system. The L3 cache events are added into perf event
> + subsystem, allowing monitoring of various L3 cache perf events.
> +
> config ARM_PMU_ACPI
> depends on ARM_PMU && ACPI
> def_bool y
> diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
> index 16b3ec4db916..e2153aee1e04 100644
> --- a/drivers/perf/Makefile
> +++ b/drivers/perf/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
> obj-$(CONFIG_RISCV_PMU) += riscv_pmu.o
> obj-$(CONFIG_RISCV_PMU_LEGACY) += riscv_pmu_legacy.o
> obj-$(CONFIG_RISCV_PMU_SBI) += riscv_pmu_sbi.o
> +obj-$(CONFIG_STARFIVE_STARLINK_PMU) += starfive_starlink_pmu.o
> obj-$(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/starfive_starlink_pmu.c b/drivers/perf/starfive_starlink_pmu.c
> new file mode 100644
> index 000000000000..272896ab1ade
> --- /dev/null
> +++ b/drivers/perf/starfive_starlink_pmu.c
> @@ -0,0 +1,654 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * StarFive's StarLink PMU driver
> + *
> + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> + *
> + * Author: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> + *
> + */
> +
> +#define STARLINK_PMU_PDEV_NAME "starfive_starlink_pmu"
> +#define pr_fmt(fmt) STARLINK_PMU_PDEV_NAME ": " fmt
> +
> +#include <linux/bitmap.h>
> +#include <linux/cpu_pm.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
You probably don't need this header and the implicit includes it makes
are dropped now in linux-next. Please check what you actually need and
make them explicit.
Rob
On Mon, 11 Dec 2023 11:54:25 -0600
Rob Herring <robh+dt@kernel.org> wrote:
> On Thu, Nov 16, 2023 at 10:24 AM Ji Sheng Teoh
> <jisheng.teoh@starfivetech.com> wrote:
> >
> > This patch adds support for StarFive's StarLink PMU (Performance
> > Monitor Unit). StarLink PMU integrates one or more CPU cores with
> > a shared L3 memory system. The PMU supports overflow interrupt,
> > up to 16 programmable 64bit event counters, and an independent
> > 64bit cycle counter. StarLink PMU is accessed via MMIO.
> >
> > Example Perf stat output:
> > [root@user]# perf stat -a -e /starfive_starlink_pmu/cycles/ \
> > -e /starfive_starlink_pmu/read_miss/ \
> > -e /starfive_starlink_pmu/read_hit/ \
> > -e /starfive_starlink_pmu/release_request/ \
> > -e /starfive_starlink_pmu/write_hit/ \
> > -e /starfive_starlink_pmu/write_miss/ \
> > -e /starfive_starlink_pmu/write_request/ \
> > -e /starfive_starlink_pmu/writeback/ \
> > -e /starfive_starlink_pmu/read_request/ \
> > -- openssl speed rsa2048
> > Doing 2048 bits private rsa's for 10s: 5 2048 bits private RSA's in
> > 2.84s
> > Doing 2048 bits public rsa's for 10s: 169 2048 bits public RSA's in
> > 2.42s
> > version: 3.0.11
> > built on: Tue Sep 19 13:02:31 2023 UTC
> > options: bn(64,64)
> > CPUINFO: N/A
> > sign verify sign/s verify/s
> > rsa 2048 bits 0.568000s 0.014320s 1.8 69.8
> > /////////
> > Performance counter stats for 'system wide':
> >
> > 649991998 starfive_starlink_pmu/cycles/
> > 1009690 starfive_starlink_pmu/read_miss/
> > 1079750 starfive_starlink_pmu/read_hit/
> > 2089405 starfive_starlink_pmu/release_request/
> > 129 starfive_starlink_pmu/write_hit/
> > 70 starfive_starlink_pmu/write_miss/
> > 194 starfive_starlink_pmu/write_request/
> > 150080 starfive_starlink_pmu/writeback/
> > 2089423 starfive_starlink_pmu/read_request/
> >
> > 27.062755678 seconds time elapsed
> >
> > Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> > ---
> > drivers/perf/Kconfig | 9 +
> > drivers/perf/Makefile | 1 +
> > drivers/perf/starfive_starlink_pmu.c | 654
> > +++++++++++++++++++++++++++ include/linux/cpuhotplug.h |
> > 1 + 4 files changed, 665 insertions(+)
> > create mode 100644 drivers/perf/starfive_starlink_pmu.c
> >
> > diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
> > index 273d67ecf6d2..41278742ef88 100644
> > --- a/drivers/perf/Kconfig
> > +++ b/drivers/perf/Kconfig
> > @@ -86,6 +86,15 @@ config RISCV_PMU_SBI
> > full perf feature support i.e. counter overflow,
> > privilege mode filtering, counter configuration.
> >
> > +config STARFIVE_STARLINK_PMU
> > + depends on ARCH_STARFIVE
> > + bool "StarFive StarLink PMU"
> > + help
> > + Provide support for StarLink Performance Monitor Unit.
> > + StarLink Performance Monitor Unit integrates one or more
> > cores with
> > + an L3 memory system. The L3 cache events are added into
> > perf event
> > + subsystem, allowing monitoring of various L3 cache perf
> > events. +
> > config ARM_PMU_ACPI
> > depends on ARM_PMU && ACPI
> > def_bool y
> > diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
> > index 16b3ec4db916..e2153aee1e04 100644
> > --- a/drivers/perf/Makefile
> > +++ b/drivers/perf/Makefile
> > @@ -15,6 +15,7 @@ obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
> > obj-$(CONFIG_RISCV_PMU) += riscv_pmu.o
> > obj-$(CONFIG_RISCV_PMU_LEGACY) += riscv_pmu_legacy.o
> > obj-$(CONFIG_RISCV_PMU_SBI) += riscv_pmu_sbi.o
> > +obj-$(CONFIG_STARFIVE_STARLINK_PMU) += starfive_starlink_pmu.o
> > obj-$(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/starfive_starlink_pmu.c
> > b/drivers/perf/starfive_starlink_pmu.c new file mode 100644
> > index 000000000000..272896ab1ade
> > --- /dev/null
> > +++ b/drivers/perf/starfive_starlink_pmu.c
> > @@ -0,0 +1,654 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * StarFive's StarLink PMU driver
> > + *
> > + * Copyright (C) 2023 StarFive Technology Co., Ltd.
> > + *
> > + * Author: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
> > + *
> > + */
> > +
> > +#define STARLINK_PMU_PDEV_NAME "starfive_starlink_pmu"
> > +#define pr_fmt(fmt) STARLINK_PMU_PDEV_NAME ": " fmt
> > +
> > +#include <linux/bitmap.h>
> > +#include <linux/cpu_pm.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
>
> You probably don't need this header and the implicit includes it makes
> are dropped now in linux-next. Please check what you actually need and
> make them explicit.
>
> Rob
Thanks Rob, this has changed to '#include <linux/mod_devicetable.h>' in
v5 submitted recently.
https://lore.kernel.org/lkml/20231207142940.1794032-1-jisheng.teoh@starfivetech.com/T/#Z2e.:..:20231207142940.1794032-2-jisheng.teoh::40starfivetech.com:1drivers:perf:starfive_starlink_pmu.c
@@ -86,6 +86,15 @@ config RISCV_PMU_SBI
full perf feature support i.e. counter overflow, privilege mode
filtering, counter configuration.
+config STARFIVE_STARLINK_PMU
+ depends on ARCH_STARFIVE
+ bool "StarFive StarLink PMU"
+ help
+ Provide support for StarLink Performance Monitor Unit.
+ StarLink Performance Monitor Unit integrates one or more cores with
+ an L3 memory system. The L3 cache events are added into perf event
+ subsystem, allowing monitoring of various L3 cache perf events.
+
config ARM_PMU_ACPI
depends on ARM_PMU && ACPI
def_bool y
@@ -15,6 +15,7 @@ obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
obj-$(CONFIG_RISCV_PMU) += riscv_pmu.o
obj-$(CONFIG_RISCV_PMU_LEGACY) += riscv_pmu_legacy.o
obj-$(CONFIG_RISCV_PMU_SBI) += riscv_pmu_sbi.o
+obj-$(CONFIG_STARFIVE_STARLINK_PMU) += starfive_starlink_pmu.o
obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o
obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o
obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o
new file mode 100644
@@ -0,0 +1,654 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * StarFive's StarLink PMU driver
+ *
+ * Copyright (C) 2023 StarFive Technology Co., Ltd.
+ *
+ * Author: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
+ *
+ */
+
+#define STARLINK_PMU_PDEV_NAME "starfive_starlink_pmu"
+#define pr_fmt(fmt) STARLINK_PMU_PDEV_NAME ": " fmt
+
+#include <linux/bitmap.h>
+#include <linux/cpu_pm.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+
+#define STARLINK_PMU_MAX_COUNTERS 64
+#define STARLINK_PMU_NUM_COUNTERS 16
+#define STARLINK_PMU_IDX_CYCLE_COUNTER 63
+
+#define STARLINK_PMU_EVENT_SELECT 0x060
+#define STARLINK_PMU_EVENT_COUNTER 0x160
+#define STARLINK_PMU_COUNTER_MASK GENMASK_ULL(63, 0)
+#define STARLINK_PMU_CYCLE_COUNTER 0x058
+
+#define STARLINK_PMU_CONTROL 0x040
+#define STARLINK_PMU_GLOBAL_ENABLE BIT(0)
+
+#define STARLINK_PMU_INTERRUPT_ENABLE 0x050
+#define STARLINK_PMU_COUNTER_OVERFLOW_STATUS 0x048
+#define STARLINK_PMU_CYCLE_OVERFLOW_MASK BIT(63)
+
+#define CYCLES 0x058
+#define CACHE_READ_REQUEST 0x04000701
+#define CACHE_WRITE_REQUEST 0x03000001
+#define CACHE_RELEASE_REQUEST 0x0003e001
+#define CACHE_READ_HIT 0x00901202
+#define CACHE_READ_MISS 0x04008002
+#define CACHE_WRITE_HIT 0x006c0002
+#define CACHE_WRITE_MISS 0x03000002
+#define CACHE_WRITEBACK 0x00000403
+
+#define to_starlink_pmu(p) (container_of(p, struct starlink_pmu, pmu))
+
+#define STARLINK_FORMAT_ATTR(_name, _config) \
+ (&((struct dev_ext_attribute[]) { \
+ { .attr = __ATTR(_name, 0444, starlink_pmu_sysfs_format_show, NULL), \
+ .var = (void *)_config, } \
+ })[0].attr.attr)
+
+#define STARLINK_EVENT_ATTR(_name, _id) \
+ PMU_EVENT_ATTR_ID(_name, starlink_pmu_sysfs_event_show, _id)
+
+#define BIT_IS_SET(nr, bit) (((nr) >> (bit)) & 0x1)
+
+struct starlink_hw_events {
+ struct perf_event *events[STARLINK_PMU_MAX_COUNTERS];
+ DECLARE_BITMAP(used_mask, STARLINK_PMU_MAX_COUNTERS);
+};
+
+struct starlink_pmu {
+ struct pmu pmu;
+ struct starlink_hw_events __percpu *hw_events;
+ struct hlist_node node;
+ struct notifier_block starlink_pmu_pm_nb;
+ void __iomem *pmu_base;
+ cpumask_t cpumask;
+ int irq;
+};
+
+/* Formats Attr */
+static ssize_t
+starlink_pmu_sysfs_format_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct dev_ext_attribute *eattr = container_of(attr,
+ struct dev_ext_attribute, attr);
+
+ return sysfs_emit(buf, "%s\n", (char *)eattr->var);
+}
+
+static struct attribute *starlink_pmu_format_attrs[] = {
+ STARLINK_FORMAT_ATTR(event, "config:0-31"),
+ NULL,
+};
+
+static const struct attribute_group starlink_pmu_format_attr_group = {
+ .name = "format",
+ .attrs = starlink_pmu_format_attrs,
+};
+
+/* Events Attr */
+static ssize_t
+starlink_pmu_sysfs_event_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct perf_pmu_events_attr *eattr = container_of(attr,
+ struct perf_pmu_events_attr, attr);
+
+ return sysfs_emit(buf, "event=0x%02llx\n", eattr->id);
+}
+
+static struct attribute *starlink_pmu_event_attrs[] = {
+ STARLINK_EVENT_ATTR(cycles, CYCLES),
+ STARLINK_EVENT_ATTR(read_request, CACHE_READ_REQUEST),
+ STARLINK_EVENT_ATTR(write_request, CACHE_WRITE_REQUEST),
+ STARLINK_EVENT_ATTR(release_request, CACHE_RELEASE_REQUEST),
+ STARLINK_EVENT_ATTR(read_hit, CACHE_READ_HIT),
+ STARLINK_EVENT_ATTR(read_miss, CACHE_READ_MISS),
+ STARLINK_EVENT_ATTR(write_hit, CACHE_WRITE_HIT),
+ STARLINK_EVENT_ATTR(write_miss, CACHE_WRITE_MISS),
+ STARLINK_EVENT_ATTR(writeback, CACHE_WRITEBACK),
+ NULL,
+};
+
+static const struct attribute_group starlink_pmu_events_attr_group = {
+ .name = "events",
+ .attrs = starlink_pmu_event_attrs,
+};
+
+/* Cpumask Attr */
+static ssize_t
+cpumask_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(dev_get_drvdata(dev));
+
+ return cpumap_print_to_pagebuf(true, buf, &starlink_pmu->cpumask);
+}
+
+static DEVICE_ATTR_RO(cpumask);
+
+static struct attribute *starlink_pmu_cpumask_attrs[] = {
+ &dev_attr_cpumask.attr,
+ NULL,
+};
+
+static const struct attribute_group starlink_pmu_cpumask_attr_group = {
+ .attrs = starlink_pmu_cpumask_attrs,
+};
+
+static const struct attribute_group *starlink_pmu_attr_groups[] = {
+ &starlink_pmu_format_attr_group,
+ &starlink_pmu_events_attr_group,
+ &starlink_pmu_cpumask_attr_group,
+ NULL,
+};
+
+static void starlink_pmu_set_event_period(struct perf_event *event)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = event->hw.idx;
+
+ /*
+ * Program counter to half of it's max count to handle
+ * cases of extreme interrupt latency.
+ */
+ u64 val = STARLINK_PMU_COUNTER_MASK >> 1;
+
+ local64_set(&hwc->prev_count, val);
+ if (hwc->config == CYCLES)
+ writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_CYCLE_COUNTER);
+ else
+ writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_EVENT_COUNTER +
+ idx * sizeof(u64));
+}
+
+static void starlink_pmu_counter_start(struct perf_event *event,
+ struct starlink_pmu *starlink_pmu)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = event->hw.idx;
+ u64 val;
+
+ /*
+ * Enable counter overflow interrupt[63:0],
+ * which is mapped as follow:
+ *
+ * event counter 0 - Bit [0]
+ * event counter 1 - Bit [1]
+ * ...
+ * cycle counter - Bit [63]
+ */
+ val = readq(starlink_pmu->pmu_base + STARLINK_PMU_INTERRUPT_ENABLE);
+
+ if (hwc->config == CYCLES) {
+ /*
+ * Cycle count has its dedicated register, and it starts
+ * counting as soon as STARLINK_PMU_GLOBAL_ENABLE is set.
+ */
+
+ /* Mask cycle counter overflow interrupt enable bit */
+ val |= STARLINK_PMU_CYCLE_OVERFLOW_MASK;
+ } else {
+ /* Enable event to monitor through event select register */
+ writeq(event->hw.config, starlink_pmu->pmu_base +
+ STARLINK_PMU_EVENT_SELECT + idx * sizeof(u64));
+
+ /* Mask event counter overflow interrupt enable bit */
+ val |= (1 << idx);
+ }
+
+ writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_INTERRUPT_ENABLE);
+
+ /* Enable the counter to start counting */
+ writeq(STARLINK_PMU_GLOBAL_ENABLE, starlink_pmu->pmu_base +
+ STARLINK_PMU_CONTROL);
+}
+
+static void starlink_pmu_counter_stop(struct perf_event *event,
+ struct starlink_pmu *starlink_pmu)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = event->hw.idx;
+ u64 val;
+
+ /* Stop counter */
+ val = readq(starlink_pmu->pmu_base + STARLINK_PMU_CONTROL);
+ val &= ~STARLINK_PMU_GLOBAL_ENABLE;
+ writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_CONTROL);
+
+ /* Disable counter overflow interrupt */
+ val = readq(starlink_pmu->pmu_base + STARLINK_PMU_INTERRUPT_ENABLE);
+ if (hwc->config == CYCLES)
+ val &= ~STARLINK_PMU_CYCLE_OVERFLOW_MASK;
+ else
+ val &= ~(1 << idx);
+
+ writeq(val, starlink_pmu->pmu_base + STARLINK_PMU_INTERRUPT_ENABLE);
+}
+
+static void starlink_pmu_update(struct perf_event *event)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+ u64 prev_raw_count, new_raw_count;
+ u64 oldval;
+ u64 delta;
+
+ do {
+ prev_raw_count = local64_read(&hwc->prev_count);
+ if (hwc->config == CYCLES)
+ new_raw_count = readq(starlink_pmu->pmu_base +
+ STARLINK_PMU_CYCLE_COUNTER);
+ else
+ new_raw_count = readq(starlink_pmu->pmu_base +
+ STARLINK_PMU_EVENT_COUNTER +
+ idx * sizeof(u64));
+ oldval = local64_cmpxchg(&hwc->prev_count, prev_raw_count,
+ new_raw_count);
+ } while (oldval != prev_raw_count);
+
+ delta = (new_raw_count - prev_raw_count) & STARLINK_PMU_COUNTER_MASK;
+ local64_add(delta, &event->count);
+}
+
+static void starlink_pmu_start(struct perf_event *event, int flags)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+
+ if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
+ return;
+
+ if (flags & PERF_EF_RELOAD)
+ WARN_ON_ONCE(!(event->hw.state & PERF_HES_UPTODATE));
+
+ hwc->state = 0;
+
+ starlink_pmu_set_event_period(event);
+ starlink_pmu_counter_start(event, starlink_pmu);
+
+ perf_event_update_userpage(event);
+}
+
+static void starlink_pmu_stop(struct perf_event *event, int flags)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+
+ if (hwc->state & PERF_HES_STOPPED)
+ return;
+
+ starlink_pmu_counter_stop(event, starlink_pmu);
+ starlink_pmu_update(event);
+ hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int starlink_pmu_add(struct perf_event *event, int flags)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct starlink_hw_events *hw_events =
+ this_cpu_ptr(starlink_pmu->hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+ unsigned long *used_mask = hw_events->used_mask;
+ u32 n_events = STARLINK_PMU_NUM_COUNTERS;
+ int idx;
+
+ /*
+ * Cycle counter has dedicated register to hold counter value.
+ * Event other than cycle count has to be enabled through
+ * event select register, and assigned with independent counter
+ * as they appear.
+ */
+
+ if (hwc->config == CYCLES) {
+ idx = STARLINK_PMU_IDX_CYCLE_COUNTER;
+ } else {
+ idx = find_first_zero_bit(used_mask, n_events);
+ /* All counter are in use */
+ if (idx < 0)
+ return idx;
+
+ set_bit(idx, used_mask);
+ }
+ /* Tie counter idx to this event */
+ hwc->idx = idx;
+ hw_events->events[idx] = event;
+ hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
+
+ if (flags & PERF_EF_START)
+ starlink_pmu_start(event, PERF_EF_RELOAD);
+
+ perf_event_update_userpage(event);
+
+ return 0;
+}
+
+static void starlink_pmu_del(struct perf_event *event, int flags)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct starlink_hw_events *hw_events =
+ this_cpu_ptr(starlink_pmu->hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+
+ starlink_pmu_stop(event, PERF_EF_UPDATE);
+ hw_events->events[hwc->idx] = NULL;
+ clear_bit(hwc->idx, hw_events->used_mask);
+
+ perf_event_update_userpage(event);
+}
+
+static bool starlink_pmu_validate_event_group(struct perf_event *event)
+{
+ struct perf_event *leader = event->group_leader;
+ struct perf_event *sibling;
+ int counter = 1;
+
+ /*
+ * Ensure hardware events in the group are on the same PMU,
+ * software events are acceptable.
+ */
+ if (event->group_leader->pmu != event->pmu &&
+ !is_software_event(event->group_leader))
+ return false;
+
+ for_each_sibling_event(sibling, leader) {
+ if (sibling->pmu != event->pmu && !is_software_event(sibling))
+ return false;
+
+ counter += 1;
+ }
+ /*
+ * Limit the number of requested counter to
+ * counter available on the HW.
+ */
+ return counter <= STARLINK_PMU_NUM_COUNTERS;
+}
+
+static int starlink_pmu_event_init(struct perf_event *event)
+{
+ struct starlink_pmu *starlink_pmu = to_starlink_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+
+ /*
+ * Sampling is not supported, as counters are shared
+ * by all CPU.
+ */
+ if (hwc->sample_period)
+ return -EOPNOTSUPP;
+
+ /*
+ * Per-task and attach to a task are not supported,
+ * as uncore events are not specific to any CPU.
+ */
+ if (event->cpu < 0 || event->attach_state & PERF_ATTACH_TASK)
+ return -EOPNOTSUPP;
+
+ /* Validate event group */
+ if (!starlink_pmu_validate_event_group(event))
+ return -EINVAL;
+
+ hwc->idx = -1;
+ hwc->config = event->attr.config;
+ event->cpu = cpumask_first(&starlink_pmu->cpumask);
+
+ return 0;
+}
+
+static irqreturn_t starlink_pmu_handle_irq(int irq_num, void *data)
+{
+ struct starlink_pmu *starlink_pmu = data;
+ struct starlink_hw_events *hw_events =
+ this_cpu_ptr(starlink_pmu->hw_events);
+ bool handled = false;
+ int idx;
+ u64 overflow_status;
+
+ for (idx = 0; idx < STARLINK_PMU_MAX_COUNTERS; idx++) {
+ struct perf_event *event = hw_events->events[idx];
+
+ overflow_status = readq(starlink_pmu->pmu_base +
+ STARLINK_PMU_COUNTER_OVERFLOW_STATUS);
+ if (!BIT_IS_SET(overflow_status, idx))
+ continue;
+
+ /* Clear event counter overflow interrupt */
+ writeq(1 << idx, starlink_pmu->pmu_base +
+ STARLINK_PMU_COUNTER_OVERFLOW_STATUS);
+
+ if (!event)
+ continue;
+
+ starlink_pmu_update(event);
+ starlink_pmu_set_event_period(event);
+ handled = true;
+ }
+ return IRQ_RETVAL(handled);
+}
+
+static int starlink_setup_irqs(struct starlink_pmu *starlink_pmu,
+ struct platform_device *pdev)
+{
+ int ret, irq;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return -EINVAL;
+
+ ret = devm_request_irq(&pdev->dev, irq, starlink_pmu_handle_irq,
+ 0, STARLINK_PMU_PDEV_NAME, starlink_pmu);
+ if (ret) {
+ dev_warn(&pdev->dev, "Failed to request IRQ %d\n", irq);
+ return ret;
+ }
+
+ starlink_pmu->irq = irq;
+
+ return 0;
+}
+
+#ifdef CONFIG_CPU_PM
+static int starlink_pmu_pm_notify(struct notifier_block *b,
+ unsigned long cmd, void *v)
+{
+ struct starlink_pmu *starlink_pmu = container_of(b, struct starlink_pmu,
+ starlink_pmu_pm_nb);
+ struct starlink_hw_events *hw_events =
+ this_cpu_ptr(starlink_pmu->hw_events);
+ int enabled = bitmap_weight(hw_events->used_mask,
+ STARLINK_PMU_MAX_COUNTERS);
+ struct perf_event *event;
+ int idx;
+
+ if (!enabled)
+ return NOTIFY_OK;
+
+ for (idx = 0; idx < STARLINK_PMU_MAX_COUNTERS; idx++) {
+ event = hw_events->events[idx];
+ if (!event)
+ continue;
+
+ switch (cmd) {
+ case CPU_PM_ENTER:
+ /* Stop and update the counter */
+ starlink_pmu_stop(event, PERF_EF_UPDATE);
+ break;
+ case CPU_PM_EXIT:
+ case CPU_PM_ENTER_FAILED:
+ /* Restore and enable the counter */
+ starlink_pmu_start(event, PERF_EF_RELOAD);
+ break;
+ default:
+ break;
+ }
+ }
+
+ return NOTIFY_OK;
+}
+
+static int starlink_pmu_pm_register(struct starlink_pmu *starlink_pmu)
+{
+ starlink_pmu->starlink_pmu_pm_nb.notifier_call = starlink_pmu_pm_notify;
+ return cpu_pm_register_notifier(&starlink_pmu->starlink_pmu_pm_nb);
+}
+
+static void starlink_pmu_pm_unregister(struct starlink_pmu *starlink_pmu)
+{
+ cpu_pm_unregister_notifier(&starlink_pmu->starlink_pmu_pm_nb);
+}
+#else
+static inline int
+starlink_pmu_pm_register(struct starlink_pmu *starlink_pmu) { return 0; }
+static inline void
+starlink_pmu_pm_unregister(struct starlink_pmu *starlink_pmu) { }
+#endif
+
+static void starlink_pmu_destroy(struct starlink_pmu *starlink_pmu)
+{
+ starlink_pmu_pm_unregister(starlink_pmu);
+ cpuhp_state_remove_instance(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
+ &starlink_pmu->node);
+}
+
+static int starlink_pmu_probe(struct platform_device *pdev)
+{
+ struct starlink_pmu *starlink_pmu;
+ struct starlink_hw_events *hw_events;
+ struct resource *res;
+ int cpuid, i, ret;
+
+ starlink_pmu = devm_kzalloc(&pdev->dev, sizeof(*starlink_pmu), GFP_KERNEL);
+ if (!starlink_pmu)
+ return -ENOMEM;
+
+ starlink_pmu->pmu_base =
+ devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(starlink_pmu->pmu_base))
+ return PTR_ERR(starlink_pmu->pmu_base);
+
+ ret = starlink_setup_irqs(starlink_pmu, pdev);
+
+ ret = cpuhp_state_add_instance(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
+ &starlink_pmu->node);
+ if (ret)
+ return ret;
+
+ ret = starlink_pmu_pm_register(starlink_pmu);
+ if (ret)
+ starlink_pmu_destroy(starlink_pmu);
+
+ starlink_pmu->hw_events = alloc_percpu_gfp(struct starlink_hw_events,
+ GFP_KERNEL);
+ if (!starlink_pmu->hw_events) {
+ pr_info("Failed to allocate per-cpu PMU data.\n");
+ kfree(starlink_pmu);
+ return -ENOMEM;
+ }
+
+ for_each_possible_cpu(cpuid) {
+ hw_events = per_cpu_ptr(starlink_pmu->hw_events, cpuid);
+ for (i = 0; i < STARLINK_PMU_MAX_COUNTERS; i++)
+ hw_events->events[i] = NULL;
+ }
+
+ starlink_pmu->pmu = (struct pmu) {
+ .task_ctx_nr = perf_invalid_context,
+ .event_init = starlink_pmu_event_init,
+ .add = starlink_pmu_add,
+ .del = starlink_pmu_del,
+ .start = starlink_pmu_start,
+ .stop = starlink_pmu_stop,
+ .read = starlink_pmu_update,
+ .attr_groups = starlink_pmu_attr_groups,
+ };
+
+ ret = perf_pmu_register(&starlink_pmu->pmu, STARLINK_PMU_PDEV_NAME, -1);
+ if (ret)
+ starlink_pmu_destroy(starlink_pmu);
+
+ dev_info(&pdev->dev, "Registered StarFive's StarLink PMU\n");
+
+ return ret;
+}
+
+static const struct of_device_id starlink_pmu_of_match[] = {
+ { .compatible = "starfive,jh8100-starlink-pmu", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, starlink_pmu_of_match);
+
+static struct platform_driver starlink_pmu_driver = {
+ .driver = {
+ .name = STARLINK_PMU_PDEV_NAME,
+ .of_match_table = starlink_pmu_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = starlink_pmu_probe,
+};
+
+static int
+starlink_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct starlink_pmu *starlink_pmu = hlist_entry_safe(node,
+ struct starlink_pmu,
+ node);
+
+ if (cpumask_empty(&starlink_pmu->cpumask))
+ cpumask_set_cpu(cpu, &starlink_pmu->cpumask);
+
+ WARN_ON(irq_set_affinity(starlink_pmu->irq, cpumask_of(cpu)));
+
+ return 0;
+}
+
+static int
+starlink_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct starlink_pmu *starlink_pmu = hlist_entry_safe(node,
+ struct starlink_pmu,
+ node);
+ unsigned int target;
+
+ if (!cpumask_test_and_clear_cpu(cpu, &starlink_pmu->cpumask))
+ return 0;
+
+ target = cpumask_any_but(cpu_online_mask, cpu);
+ if (target >= nr_cpu_ids)
+ return 0;
+
+ perf_pmu_migrate_context(&starlink_pmu->pmu, cpu, target);
+
+ cpumask_set_cpu(target, &starlink_pmu->cpumask);
+ WARN_ON(irq_set_affinity(starlink_pmu->irq, cpumask_of(target)));
+
+ return 0;
+}
+
+static int __init starlink_pmu_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state_multi(CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
+ "soc/starfive/starlink_pmu:online",
+ starlink_pmu_online_cpu,
+ starlink_pmu_offline_cpu);
+ if (ret)
+ return ret;
+
+ return platform_driver_register(&starlink_pmu_driver);
+}
+
+device_initcall(starlink_pmu_init);
@@ -219,6 +219,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_X86_CQM_ONLINE,
CPUHP_AP_PERF_X86_CSTATE_ONLINE,
CPUHP_AP_PERF_X86_IDXD_ONLINE,
+ CPUHP_AP_PERF_RISCV_STARFIVE_STARLINK_ONLINE,
CPUHP_AP_PERF_S390_CF_ONLINE,
CPUHP_AP_PERF_S390_SF_ONLINE,
CPUHP_AP_PERF_ARM_CCI_ONLINE,