[PATCH v6 1/2] perf: Fujitsu: Add the Uncore MAC PMU driver
Koichi Okuno (Fujitsu)
fj2767dz at fujitsu.com
Thu Jul 17 23:00:48 PDT 2025
Hi, Jonathan
> > This adds two new dynamic PMUs to the Perf Events framework to program
> > and control the Uncore MAC PMUs in Fujitsu chips.
> >
> > These drivers were created with reference to drivers/perf/qcom_l3_pmu.c.
> >
> > These drivers export formatting and event information to sysfs so they can
> > be used by the perf user space tools with the syntaxes:
> >
> > perf stat -e mac_iod0_mac0_ch0/ea-mac/ ls
> > perf stat -e mac_iod0_mac0_ch0/event=0x80/ ls
> >
> > FUJITSU-MONAKA PMU Events Specification v1.1 URL:
> > https://github.com/fujitsu/FUJITSU-MONAKA
> >
> > Signed-off-by: Koichi Okuno <fj2767dz at fujitsu.com>
> Hi
>
> We may have discussed on an earlier version and I've forgotten about it
> (in which case sorry!) but why can't this be modular?
>
> Given the chances are we will want it in standard distributions, a
> bool kconfig seems to ensure bloat that people are not going to want to
> see.
It follows qcom_l3_pmu.c which is the base of this driver, so I would like
to keep it that way.
> A few other minor comments inline.
>
> Thanks,
>
> Jonathan
>
> > ---
> > .../admin-guide/perf/fujitsu_mac_pmu.rst | 73 +++
> > Documentation/admin-guide/perf/index.rst | 1 +
> > drivers/perf/Kconfig | 9 +
> > drivers/perf/Makefile | 1 +
> > drivers/perf/fujitsu_mac_pmu.c | 569 ++++++++++++++++++
> > 5 files changed, 653 insertions(+)
> > create mode 100644 Documentation/admin-guide/perf/fujitsu_mac_pmu.rst
> > create mode 100644 drivers/perf/fujitsu_mac_pmu.c
> >
> > diff --git a/Documentation/admin-guide/perf/fujitsu_mac_pmu.rst b/Documentation/admin-guide/perf/fujitsu_mac_pmu.rst
> > new file mode 100644
> > index 000000000000..383f3c1bbde7
> > --- /dev/null
> > +++ b/Documentation/admin-guide/perf/fujitsu_mac_pmu.rst
> > @@ -0,0 +1,73 @@
> > +====================================================
> > +Fujitsu Uncore MAC Performance Monitoring Unit (PMU)
> > +====================================================
> > +
> > +This driver supports the Uncore MAC PMUs found in Fujitsu chips.
> > +Each MAC PMU on these chips is exposed as a uncore perf PMU with device name
> > +mac_iod<iod>_mac<mac>_ch<ch>.
> > +
> > +The driver provides a description of its available events and configuration
> > +options in sysfs, see /sys/bus/event_sources/devices/mac_iod<iod>_mac<mac>_ch<ch>/.
> > +This driver exports:
> > +- formats, used by perf user space and other tools to configure events
> > +- events, used by perf user space and other tools to create events
> > + symbolically, e.g.:
> > + perf stat -a -e mac_iod0_mac0_ch0/event=0x21/ ls
> > +- cpumask, used by perf user space and other tools to know on which CPUs
> > + to open the events
> > +
> > +This driver supports the following events:
> > +- cycles
> > + This event counts MAC cycles at MAC frequency.
>
> Trivial but you could shorten all these by rewording to drop the This Event and counts
> as both obvious from context.
>
> - cycles
> MAC Cycles at MAC frequency.
> - read-count
> Number of read requests to MAC.
> etc
These descriptions follow the FUJITSU-MONAKA PMU Events Specification(v1.1).
https://github.com/fujitsu/FUJITSU-MONAKA
I'd like to keep the current format.
> > +- read-count
> > + This event counts the number of read requests to MAC.
> > +- read-count-request
> > + This event counts the number of read requests including retry to MAC.
> > +- read-count-return
> > + This event counts the number of responses to read requests to MAC.
> > +- read-count-request-pftgt
> > + This event counts the number of read requests including retry with PFTGT
> > + flag.
> > +- read-count-request-normal
> > + This event counts the number of read requests including retry without PFTGT
> > + flag.
> > +- read-count-return-pftgt-hit
> > + This event counts the number of responses to read requests which hit the
> > + PFTGT buffer.
> > +- read-count-return-pftgt-miss
> > + This event counts the number of responses to read requests which miss the
> > + PFTGT buffer.
> > +- read-wait
> > + This event counts outstanding read requests issued by DDR memory controller
> > + per cycle.
> > +- write-count
> > + This event counts the number of write requests to MAC (including zero write,
> > + full write, partial write, write cancel).
> > +- write-count-write
> > + This event counts the number of full write requests to MAC (not including
> > + zero write).
> > +- write-count-pwrite
> > + This event counts the number of partial write requests to MAC.
> > +- memory-read-count
> > + This event counts the number of read requests from MAC to memory.
> > +- memory-write-count
> > + This event counts the number of full write requests from MAC to memory.
> > +- memory-pwrite-count
> > + This event counts the number of partial write requests from MAC to memory.
> > +- ea-mac
> > + This event counts energy consumption of MAC.
> > +- ea-memory
> > + This event counts energy consumption of memory.
> > +- ea-memory-mac-write
> > + This event counts the number of write requests from MAC to memory.
> > +- ea-ha
> > + This event counts energy consumption of HA.
> > +
> > + 'ea' is the abbreviation for 'Energy Analyzer'.
> > +
> > +Examples for use with perf::
> > +
> > + perf stat -e mac_iod0_mac0_ch0/ea-mac/ ls
> > +
> > +Given that these are uncore PMUs the driver does not support sampling, therefore
> > +"perf record" will not work. Per-task perf sessions are not supported.
>
> > diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
> > index 278c929dc87a..269bf72a512a 100644
> > --- a/drivers/perf/Kconfig
> > +++ b/drivers/perf/Kconfig
> > @@ -178,6 +178,15 @@ config FSL_IMX9_DDR_PMU
> > can give information about memory throughput and other related
> > events.
> >
> > +config FUJITSU_MAC_PMU
> > + bool "Fujitsu Uncore MAC PMU"
>
> We may have discussed this in an earlier version but why not
> tristate? + module_init()
Same as first answer, but follows qcom_l3_pmu.c, which is the base of this driver,
so I would like to keep it that way.
> > + depends on (ARM64 && (ACPI || COMPILE_TEST))
> > + help
> > + Provides support for the Uncore MAC performance monitor unit (PMU)
> > + in Fujitsu processors.
> > + Adds the Uncore MAC PMU into the perf events subsystem for
> > + monitoring Uncore MAC events.
> > +
> > config QCOM_L2_PMU
> > bool "Qualcomm Technologies L2-cache PMU"
> > depends on ARCH_QCOM && ARM64 && ACPI
>
> > diff --git a/drivers/perf/fujitsu_mac_pmu.c b/drivers/perf/fujitsu_mac_pmu.c
> > new file mode 100644
> > index 000000000000..3c5e838b9894
> > --- /dev/null
> > +++ b/drivers/perf/fujitsu_mac_pmu.c
> > @@ -0,0 +1,569 @@
>
> > +
> > +#include <linux/acpi.h>
> > +#include <linux/bitops.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/list.h>
> > +#include <linux/mod_devicetable.h>
> > +#include <linux/module.h>
> > +#include <linux/perf_event.h>
> > +#include <linux/platform_device.h>
> > +
> > +/* Number of counters on each PMU */
> > +#define MAC_NUM_COUNTERS 8
> > +/* Mask for the event type field within perf_event_attr.config and EVTYPE reg */
> > +#define MAC_EVTYPE_MASK 0xFF
> > +
> > +/* Perfmon registers */
> > +#define MAC_PM_EVCNTR(__cntr) (0x000 + (__cntr) * 8)
> > +#define MAC_PM_CNTCTL(__cntr) (0x100 + (__cntr) * 8)
> > +#define MAC_PM_EVTYPE(__cntr) (0x200 + (__cntr) * 8)
> > +#define MAC_PM_CR 0x400
> > +#define MAC_PM_CNTENSET 0x410
> > +#define MAC_PM_CNTENCLR 0x418
> > +#define MAC_PM_INTENSET 0x420
> > +#define MAC_PM_INTENCLR 0x428
> > +#define MAC_PM_OVSR 0x440
>
> > +
> > +/* MAC_PM_INTENCLR */
> > +#define PMINTENCLR(__cntr) BIT(__cntr)
> > +#define PM_INTENCLR_RESET 0xFF
> > +
> > +/* MAC_PM_OVSR */
>
> I'd rather see the macros named to make it clear which register
> they apply to sufficiently that the comments aren't needed.
> Also in my view good to put them directly under the register definine.
I agree.
I rename the macros name to make it clear which register it applies to.
Place it directly below the register definition and remove the comment.
> > +#define PMOVSRCLR(__cntr) BIT(__cntr)
> Not used.
Understood.
Delete not used macro.
> > +#define PMOVSRCLR_RESET 0xFF
>
>
> > +/*
> > + * We must NOT create groups containing events from multiple hardware PMUs,
> > + * although mixing different software and hardware PMUs is allowed.
> > + */
> > +static bool fujitsu_mac__validate_event_group(struct perf_event *event)
> > +{
> > + struct perf_event *leader = event->group_leader;
> > + struct perf_event *sibling;
> > + int counters = 0;
>
> Value never used.
Understood.
I'll change the counter to not set to 0.
> > +
> > + if (leader->pmu != event->pmu && !is_software_event(leader))
> > + return false;
> > +
> > + /* The sum of the counters used by the event and its leader event */
> > + counters = 2;
> > +
> > + for_each_sibling_event(sibling, leader) {
> > + if (is_software_event(sibling))
> > + continue;
> > + if (sibling->pmu != event->pmu)
> > + return false;
> > + counters++;
> > + }
> > +
> > + /*
> > + * If the group requires more counters than the HW has, it
> > + * cannot ever be scheduled.
> > + */
> > + return counters <= MAC_NUM_COUNTERS;
> > +}
>
> > +static int fujitsu_mac_pmu_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct acpi_device *acpi_dev;
> > + struct mac_pmu *macpmu;
> > + struct resource *memrc;
> > + char *name;
> > + int ret;
> > + u64 uid;
> > +
> > + acpi_dev = ACPI_COMPANION(dev);
> > + if (!acpi_dev)
> > + return -ENODEV;
> > +
> > + ret = acpi_dev_uid_to_integer(acpi_dev, &uid);
> > + if (ret)
> > + return dev_err_probe(dev, ret, "unable to read ACPI uid\n");
> > +
> > + macpmu = devm_kzalloc(dev, sizeof(*macpmu), GFP_KERNEL);
> > + if (!macpmu)
> > + return -ENOMEM;
> > +
> > + name = devm_kasprintf(dev, GFP_KERNEL, "mac_iod%llu_mac%llu_ch%llu",
> > + (uid >> 8) & 0xF, (uid >> 4) & 0xF, uid & 0xF);
> > + if (!name)
> > + return -ENOMEM;
> > +
> > + macpmu->pmu = (struct pmu) {
> > + .parent = dev,
> > + .task_ctx_nr = perf_invalid_context,
> > +
> > + .pmu_enable = fujitsu_mac__pmu_enable,
> > + .pmu_disable = fujitsu_mac__pmu_disable,
> > + .event_init = fujitsu_mac__event_init,
> > + .add = fujitsu_mac__event_add,
> > + .del = fujitsu_mac__event_del,
> > + .start = fujitsu_mac__event_start,
> > + .stop = fujitsu_mac__event_stop,
> > + .read = fujitsu_mac__event_read,
> > +
> > + .attr_groups = fujitsu_mac_pmu_attr_grps,
> > + .capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
> > + };
> > +
> > + macpmu->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &memrc);
> > + if (IS_ERR(macpmu->regs))
> > + return PTR_ERR(macpmu->regs);
> > +
> > + fujitsu_mac__init(macpmu);
> > +
> > + ret = platform_get_irq(pdev, 0);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = devm_request_irq(dev, ret, fujitsu_mac__handle_irq, 0,
> > + name, macpmu);
>
> Unusual indentation. Normally second line of parametes should just be
> aligned under first set of parameters. E.g.
>
> ret = devm_request_irq(dev, ret, fujitsu_mac__handle_irq, 0,
> name, macpmu);
>
This line was adjusted in Tab4, so I will change it to be adjusted in Tab8.
> > + if (ret)
> > + return dev_err_probe(dev, ret, "Request for IRQ failed for slice @%pa\n",
> > + &memrc->start);
>
> Similar for this second line set of parameters.
Understood.
> > +
> > + /* Add this instance to the list used by the offline callback */
> > + ret = cpuhp_state_add_instance(mac_pmu_cpuhp_state, &macpmu->node);
> > + if (ret)
> > + return dev_err_probe(dev, ret, "Error registering hotplug");
> > +
> > + ret = perf_pmu_register(&macpmu->pmu, name, -1);
> > + if (ret < 0)
> > + return dev_err_probe(dev, ret, "Failed to register MAC PMU\n");
> > +
> > + dev_dbg(dev, "Registered %s, type: %d\n", name, macpmu->pmu.type);
> > +
> > + return 0;
> > +}
>
>
> > +static int __init register_fujitsu_mac_pmu_driver(void)
> > +{
> > + int ret;
> > +
> > + /* Install a hook to update the reader CPU in case it goes offline */
> > + ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
> > + "perf/fujitsu/mac:online",
> > + fujitsu_mac_pmu_online_cpu,
> > + fujitsu_mac_pmu_offline_cpu);
> > + if (ret < 0)
> > + return ret;
> > +
> > + mac_pmu_cpuhp_state = ret;
> > + return platform_driver_register(&fujitsu_mac_pmu_driver);
> > +}
> > +device_initcall(register_fujitsu_mac_pmu_driver);
>
> Perhaps add a comment on why this can be a module? Would need a trivial
> exit plus to use module_init() / module_exit()
Best Regards,
Koichi Okuno
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