[PATCH v5 0/2] perf: Fujitsu: Add Uncore MAC/PCI PMU driver

[PATCH v5 0/2] perf: Fujitsu: Add Uncore MAC/PCI PMU driver

[Koichi Okuno]

This adds two new dynamic PMUs to the Perf Events framework to program
and control the Uncore MAC/PCI 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

perf stat -e pci_iod0_pci0/ea-pci/ ls
perf stat -e pci_iod0_pci0/event=0x80/ ls

FUJITSU-MONAKA PMU Events Specification v1.1 URL:
https://github.com/fujitsu/FUJITSU-MONAKA

Changes in v5:
- Update PMU events for FUJITSU-MONAKA to latest(v1.1) spec.
  The changed events are as follows:
  - Removed events:
    ea-memory-mac-read
    ea-memory-mac-pwrite
  - Description changed events:
    read-count-return
    read-count-return-pftgt-hit
    read-count-return-pftgt-miss
    ea-mac
    ea-memory
    ea-ha
    ea-pci
- Modify the code as suggested. (Jonathan Cameron)
  - Added include mod_devicetable.h.
  - EA events that share the same description as MAC events have been
    removed.
    These events will remain in the specification, but will be removed
    from the code.
    These events will be supported in future enhancements as the
    specification changes.
  - Changed MAC events with the same description to different
    description.
  - Changed some programming styles as suggested.
- Link to v4:https://lore.kernel.org/all/20250116045911.3382537-1-fj5100bi@fujitsu.com/

Koichi Okuno (2):
  perf: Fujitsu: Add the Uncore MAC PMU driver
  perf: Fujitsu: Add the Uncore PCI PMU driver

 .../admin-guide/perf/fujitsu_mac_pmu.rst      |  73 +++
 .../admin-guide/perf/fujitsu_pci_pmu.rst      |  50 ++
 Documentation/admin-guide/perf/index.rst      |   2 +
 drivers/perf/Kconfig                          |  18 +
 drivers/perf/Makefile                         |   2 +
 drivers/perf/fujitsu_mac_pmu.c                | 569 ++++++++++++++++++
 drivers/perf/fujitsu_pci_pmu.c                | 553 +++++++++++++++++
 7 files changed, 1267 insertions(+)
 create mode 100644 Documentation/admin-guide/perf/fujitsu_mac_pmu.rst
 create mode 100644 Documentation/admin-guide/perf/fujitsu_pci_pmu.rst
 create mode 100644 drivers/perf/fujitsu_mac_pmu.c
 create mode 100644 drivers/perf/fujitsu_pci_pmu.c

-- 
2.43.0

[PATCH v5 1/2] perf: Fujitsu: Add the Uncore MAC PMU driver

[Koichi Okuno]

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@fujitsu.com>
---
 .../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.
+- 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/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
index 072b510385c4..e0262060db17 100644
--- a/Documentation/admin-guide/perf/index.rst
+++ b/Documentation/admin-guide/perf/index.rst
@@ -29,3 +29,4 @@ Performance monitor support
    cxl
    ampere_cspmu
    mrvl-pem-pmu
+   fujitsu_mac_pmu
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"
+	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/Makefile b/drivers/perf/Makefile
index de71d2574857..c9a2ba78d34f 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_ARM_SMMU_V3_PMU) += arm_smmuv3_pmu.o
 obj-$(CONFIG_FSL_IMX8_DDR_PMU) += fsl_imx8_ddr_perf.o
 obj-$(CONFIG_FSL_IMX9_DDR_PMU) += fsl_imx9_ddr_perf.o
 obj-$(CONFIG_HISI_PMU) += hisilicon/
+obj-$(CONFIG_FUJITSU_MAC_PMU) += fujitsu_mac_pmu.o
 obj-$(CONFIG_QCOM_L2_PMU)	+= qcom_l2_pmu.o
 obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
 obj-$(CONFIG_RISCV_PMU) += riscv_pmu.o
diff --git a/drivers/perf/fujitsu_mac_pmu.c b/drivers/perf/fujitsu_mac_pmu.c
new file mode 100644
index 000000000000..300df4676578
--- /dev/null
+++ b/drivers/perf/fujitsu_mac_pmu.c
@@ -0,0 +1,569 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the Uncore MAC PMUs in Fujitsu chips.
+ *
+ * See Documentation/admin-guide/perf/fujitsu_mac_pmu.rst for more details.
+ *
+ * This driver is based on drivers/perf/qcom_l3_pmu.c
+ * Copyright (c) 2015-2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2024 Fujitsu. All rights reserved.
+ */
+
+#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_CNTCTLx */
+#define PMCNT_RESET           0
+
+/* MAC_PM_EVTYPEx */
+#define EVSEL(__val)          FIELD_GET(MAC_EVTYPE_MASK, __val)
+
+/* MAC_PM_CR */
+#define PM_RESET              BIT(1)
+#define PM_ENABLE             BIT(0)
+
+/* MAC_PM_CNTENSET */
+#define PMCNTENSET(__cntr)    BIT(__cntr)
+
+/* MAC_PM_CNTENCLR */
+#define PMCNTENCLR(__cntr)    BIT(__cntr)
+#define PM_CNTENCLR_RESET     0xFF
+
+/* MAC_PM_INTENSET */
+#define PMINTENSET(__cntr)    BIT(__cntr)
+
+/* MAC_PM_INTENCLR */
+#define PMINTENCLR(__cntr)    BIT(__cntr)
+#define PM_INTENCLR_RESET     0xFF
+
+/* MAC_PM_OVSR */
+#define PMOVSRCLR(__cntr)     BIT(__cntr)
+#define PMOVSRCLR_RESET       0xFF
+
+#define MAC_EVENT_CYCLES			0x000
+#define MAC_EVENT_READ_COUNT			0x010
+#define MAC_EVENT_READ_COUNT_REQUEST		0x011
+#define MAC_EVENT_READ_COUNT_RETURN		0x012
+#define MAC_EVENT_READ_COUNT_REQUEST_PFTGT	0x013
+#define MAC_EVENT_READ_COUNT_REQUEST_NORMAL	0x014
+#define MAC_EVENT_READ_COUNT_RETURN_PFTGT_HIT	0x015
+#define MAC_EVENT_READ_COUNT_RETURN_PFTGT_MISS	0x016
+#define MAC_EVENT_READ_WAIT			0x017
+#define MAC_EVENT_WRITE_COUNT			0x020
+#define MAC_EVENT_WRITE_COUNT_WRITE		0x021
+#define MAC_EVENT_WRITE_COUNT_PWRITE		0x022
+#define MAC_EVENT_MEMORY_READ_COUNT		0x040
+#define MAC_EVENT_MEMORY_WRITE_COUNT		0x050
+#define MAC_EVENT_MEMORY_PWRITE_COUNT		0x060
+#define MAC_EVENT_EA_MAC			0x080
+#define MAC_EVENT_EA_MEMORY			0x090
+#define MAC_EVENT_EA_MEMORY_MAC_WRITE		0x092
+#define MAC_EVENT_EA_HA			0x0a0
+
+struct mac_pmu {
+	struct pmu		pmu;
+	struct hlist_node	node;
+	void __iomem		*regs;
+	struct perf_event	*events[MAC_NUM_COUNTERS];
+	unsigned long		used_mask[BITS_TO_LONGS(MAC_NUM_COUNTERS)];
+	cpumask_t		cpumask;
+};
+
+#define to_mac_pmu(p) (container_of(p, struct mac_pmu, pmu))
+
+static int mac_pmu_cpuhp_state;
+
+static void fujitsu_mac_counter_start(struct perf_event *event)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(event->pmu);
+	int idx = event->hw.idx;
+
+	/* Initialize the hardware counter and reset prev_count*/
+	local64_set(&event->hw.prev_count, 0);
+	writeq_relaxed(0, macpmu->regs + MAC_PM_EVCNTR(idx));
+
+	/* Set the event type */
+	writeq_relaxed(EVSEL(event->attr.config), macpmu->regs + MAC_PM_EVTYPE(idx));
+
+	/* Enable interrupt generation by this counter */
+	writeq_relaxed(PMINTENSET(idx), macpmu->regs + MAC_PM_INTENSET);
+
+	/* Finally, enable the counter */
+	writeq_relaxed(PMCNT_RESET, macpmu->regs + MAC_PM_CNTCTL(idx));
+	writeq_relaxed(PMCNTENSET(idx), macpmu->regs + MAC_PM_CNTENSET);
+}
+
+static void fujitsu_mac_counter_stop(struct perf_event *event,
+					      int flags)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(event->pmu);
+	int idx = event->hw.idx;
+
+	/* Disable the counter */
+	writeq_relaxed(PMCNTENCLR(idx), macpmu->regs + MAC_PM_CNTENCLR);
+
+	/* Disable interrupt generation by this counter */
+	writeq_relaxed(PMINTENCLR(idx), macpmu->regs + MAC_PM_INTENCLR);
+}
+
+static void fujitsu_mac_counter_update(struct perf_event *event)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(event->pmu);
+	int idx = event->hw.idx;
+	u64 prev, new;
+
+	do {
+		prev = local64_read(&event->hw.prev_count);
+		new = readq_relaxed(macpmu->regs + MAC_PM_EVCNTR(idx));
+	} while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
+
+	local64_add(new - prev, &event->count);
+}
+
+static inline void fujitsu_mac__init(struct mac_pmu *macpmu)
+{
+	int i;
+
+	writeq_relaxed(PM_RESET, macpmu->regs + MAC_PM_CR);
+
+	writeq_relaxed(PM_CNTENCLR_RESET, macpmu->regs + MAC_PM_CNTENCLR);
+	writeq_relaxed(PM_INTENCLR_RESET, macpmu->regs + MAC_PM_INTENCLR);
+	writeq_relaxed(PMOVSRCLR_RESET, macpmu->regs + MAC_PM_OVSR);
+
+	for (i = 0; i < MAC_NUM_COUNTERS; ++i) {
+		writeq_relaxed(PMCNT_RESET, macpmu->regs + MAC_PM_CNTCTL(i));
+		writeq_relaxed(EVSEL(0), macpmu->regs + MAC_PM_EVTYPE(i));
+	}
+
+	/*
+	 * Use writeq here to ensure all programming commands are done
+	 * before proceeding
+	 */
+	writeq(PM_ENABLE, macpmu->regs + MAC_PM_CR);
+}
+
+static irqreturn_t fujitsu_mac__handle_irq(int irq_num, void *data)
+{
+	struct mac_pmu *macpmu = data;
+	/* Read the overflow status register */
+	long status = readq_relaxed(macpmu->regs + MAC_PM_OVSR);
+	int idx;
+
+	if (status == 0)
+		return IRQ_NONE;
+
+	/* Clear the bits we read on the overflow status register */
+	writeq_relaxed(status, macpmu->regs + MAC_PM_OVSR);
+
+	for_each_set_bit(idx, &status, MAC_NUM_COUNTERS) {
+		struct perf_event *event;
+
+		event = macpmu->events[idx];
+		if (!event)
+			continue;
+
+		fujitsu_mac_counter_update(event);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void fujitsu_mac__pmu_enable(struct pmu *pmu)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(pmu);
+
+	/* Ensure the other programming commands are observed before enabling */
+	wmb();
+
+	writeq_relaxed(PM_ENABLE, macpmu->regs + MAC_PM_CR);
+}
+
+static void fujitsu_mac__pmu_disable(struct pmu *pmu)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(pmu);
+
+	writeq_relaxed(0, macpmu->regs + MAC_PM_CR);
+
+	/* Ensure the basic counter unit is stopped before proceeding */
+	wmb();
+}
+
+/*
+ * 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;
+
+	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__event_init(struct perf_event *event)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* Is the event for this PMU? */
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	/*
+	 * Sampling not supported since these events are not
+	 * core-attributable.
+	 */
+	if (hwc->sample_period)
+		return -EINVAL;
+
+	/*
+	 * Task mode not available, we run the counters as socket counters,
+	 * not attributable to any CPU and therefore cannot attribute per-task.
+	 */
+	if (event->cpu < 0)
+		return -EINVAL;
+
+	/* Validate the group */
+	if (!fujitsu_mac__validate_event_group(event))
+		return -EINVAL;
+
+	hwc->idx = -1;
+
+	/*
+	 * Many perf core operations (eg. events rotation) operate on a
+	 * single CPU context. This is obvious for CPU PMUs, where one
+	 * expects the same sets of events being observed on all CPUs,
+	 * but can lead to issues for off-core PMUs, like this one, where
+	 * each event could be theoretically assigned to a different CPU.
+	 * To mitigate this, we enforce CPU assignment to one designated
+	 * processor (the one described in the "cpumask" attribute exported
+	 * by the PMU device). perf user space tools honor this and avoid
+	 * opening more than one copy of the events.
+	 */
+	event->cpu = cpumask_first(&macpmu->cpumask);
+
+	return 0;
+}
+
+static void fujitsu_mac__event_start(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	hwc->state = 0;
+	fujitsu_mac_counter_start(event);
+}
+
+static void fujitsu_mac__event_stop(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (hwc->state & PERF_HES_STOPPED)
+		return;
+
+	fujitsu_mac_counter_stop(event, flags);
+	if (flags & PERF_EF_UPDATE)
+		fujitsu_mac_counter_update(event);
+	hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int fujitsu_mac__event_add(struct perf_event *event, int flags)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx;
+
+	/* Try to allocate a counter. */
+	idx = bitmap_find_free_region(macpmu->used_mask, MAC_NUM_COUNTERS, 0);
+	if (idx < 0)
+		/* The counters are all in use. */
+		return -EAGAIN;
+
+	hwc->idx = idx;
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+	macpmu->events[idx] = event;
+
+	if (flags & PERF_EF_START)
+		fujitsu_mac__event_start(event, 0);
+
+	/* Propagate changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+
+	return 0;
+}
+
+static void fujitsu_mac__event_del(struct perf_event *event, int flags)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* Stop and clean up */
+	fujitsu_mac__event_stop(event, flags | PERF_EF_UPDATE);
+	macpmu->events[hwc->idx] = NULL;
+	bitmap_release_region(macpmu->used_mask, hwc->idx, 0);
+
+	/* Propagate changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+}
+
+static void fujitsu_mac__event_read(struct perf_event *event)
+{
+	fujitsu_mac_counter_update(event);
+}
+
+#define MAC_PMU_FORMAT_ATTR(_name, _config)				      \
+	(&((struct dev_ext_attribute[]) {				      \
+		{ .attr = __ATTR(_name, 0444, device_show_string, NULL),      \
+		  .var = (void *) _config, }				      \
+	})[0].attr.attr)
+
+static struct attribute *fujitsu_mac_pmu_formats[] = {
+	MAC_PMU_FORMAT_ATTR(event, "config:0-7"),
+	NULL
+};
+
+static const struct attribute_group fujitsu_mac_pmu_format_group = {
+	.name = "format",
+	.attrs = fujitsu_mac_pmu_formats,
+};
+
+static ssize_t mac_pmu_event_show(struct device *dev,
+				     struct device_attribute *attr, char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+	return sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+#define MAC_EVENT_ATTR(_name, _id)					     \
+	PMU_EVENT_ATTR_ID(_name, mac_pmu_event_show, _id)
+
+static struct attribute *fujitsu_mac_pmu_events[] = {
+	MAC_EVENT_ATTR(cycles, MAC_EVENT_CYCLES),
+	MAC_EVENT_ATTR(read-count, MAC_EVENT_READ_COUNT),
+	MAC_EVENT_ATTR(read-count-request, MAC_EVENT_READ_COUNT_REQUEST),
+	MAC_EVENT_ATTR(read-count-return, MAC_EVENT_READ_COUNT_RETURN),
+	MAC_EVENT_ATTR(read-count-request-pftgt, MAC_EVENT_READ_COUNT_REQUEST_PFTGT),
+	MAC_EVENT_ATTR(read-count-request-normal, MAC_EVENT_READ_COUNT_REQUEST_NORMAL),
+	MAC_EVENT_ATTR(read-count-return-pftgt-hit, MAC_EVENT_READ_COUNT_RETURN_PFTGT_HIT),
+	MAC_EVENT_ATTR(read-count-return-pftgt-miss, MAC_EVENT_READ_COUNT_RETURN_PFTGT_MISS),
+	MAC_EVENT_ATTR(read-wait, MAC_EVENT_READ_WAIT),
+	MAC_EVENT_ATTR(write-count, MAC_EVENT_WRITE_COUNT),
+	MAC_EVENT_ATTR(write-count-write, MAC_EVENT_WRITE_COUNT_WRITE),
+	MAC_EVENT_ATTR(write-count-pwrite, MAC_EVENT_WRITE_COUNT_PWRITE),
+	MAC_EVENT_ATTR(memory-read-count, MAC_EVENT_MEMORY_READ_COUNT),
+	MAC_EVENT_ATTR(memory-write-count, MAC_EVENT_MEMORY_WRITE_COUNT),
+	MAC_EVENT_ATTR(memory-pwrite-count, MAC_EVENT_MEMORY_PWRITE_COUNT),
+	MAC_EVENT_ATTR(ea-mac, MAC_EVENT_EA_MAC),
+	MAC_EVENT_ATTR(ea-memory, MAC_EVENT_EA_MEMORY),
+	MAC_EVENT_ATTR(ea-memory-mac-write, MAC_EVENT_EA_MEMORY_MAC_WRITE),
+	MAC_EVENT_ATTR(ea-ha, MAC_EVENT_EA_HA),
+	NULL
+};
+
+static const struct attribute_group fujitsu_mac_pmu_events_group = {
+	.name = "events",
+	.attrs = fujitsu_mac_pmu_events,
+};
+
+static ssize_t cpumask_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct mac_pmu *macpmu = to_mac_pmu(dev_get_drvdata(dev));
+
+	return cpumap_print_to_pagebuf(true, buf, &macpmu->cpumask);
+}
+static DEVICE_ATTR_RO(cpumask);
+
+static struct attribute *fujitsu_mac_pmu_cpumask_attrs[] = {
+	&dev_attr_cpumask.attr,
+	NULL
+};
+
+static const struct attribute_group fujitsu_mac_pmu_cpumask_attr_group = {
+	.attrs = fujitsu_mac_pmu_cpumask_attrs,
+};
+
+static const struct attribute_group *fujitsu_mac_pmu_attr_grps[] = {
+	&fujitsu_mac_pmu_format_group,
+	&fujitsu_mac_pmu_events_group,
+	&fujitsu_mac_pmu_cpumask_attr_group,
+	NULL
+};
+
+static int fujitsu_mac_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct mac_pmu *macpmu = hlist_entry_safe(node, struct mac_pmu, node);
+
+	/* If there is not a CPU/PMU association pick this CPU */
+	if (cpumask_empty(&macpmu->cpumask))
+		cpumask_set_cpu(cpu, &macpmu->cpumask);
+
+	return 0;
+}
+
+static int fujitsu_mac_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct mac_pmu *macpmu = hlist_entry_safe(node, struct mac_pmu, node);
+	unsigned int target;
+
+	if (!cpumask_test_and_clear_cpu(cpu, &macpmu->cpumask))
+		return 0;
+
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	perf_pmu_migrate_context(&macpmu->pmu, cpu, target);
+	cpumask_set_cpu(target, &macpmu->cpumask);
+
+	return 0;
+}
+
+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,
+	};
+
+	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);
+	if (ret)
+		return dev_err_probe(dev, ret, "Request for IRQ failed for slice @%pa\n",
+							 &memrc->start);
+
+	/* 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 const struct acpi_device_id fujitsu_mac_pmu_acpi_match[] = {
+	{ "FUJI200C", },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, fujitsu_mac_pmu_acpi_match);
+
+static struct platform_driver fujitsu_mac_pmu_driver = {
+	.driver = {
+		.name = "fujitsu-mac-pmu",
+		.acpi_match_table = fujitsu_mac_pmu_acpi_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = fujitsu_mac_pmu_probe,
+};
+
+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);
-- 
2.43.0

[PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Koichi Okuno]

This adds two new dynamic PMUs to the Perf Events framework to program
and control the Uncore PCI 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 pci_iod0_pci0/ea-pci/ ls
perf stat -e pci_iod0_pci0/event=0x80/ ls

FUJITSU-MONAKA PMU Events Specification v1.1 URL:
https://github.com/fujitsu/FUJITSU-MONAKA

Signed-off-by: Koichi Okuno <fj2767dz@fujitsu.com>
---
 .../admin-guide/perf/fujitsu_pci_pmu.rst      |  50 ++
 Documentation/admin-guide/perf/index.rst      |   1 +
 drivers/perf/Kconfig                          |   9 +
 drivers/perf/Makefile                         |   1 +
 drivers/perf/fujitsu_pci_pmu.c                | 553 ++++++++++++++++++
 5 files changed, 614 insertions(+)
 create mode 100644 Documentation/admin-guide/perf/fujitsu_pci_pmu.rst
 create mode 100644 drivers/perf/fujitsu_pci_pmu.c

diff --git a/Documentation/admin-guide/perf/fujitsu_pci_pmu.rst b/Documentation/admin-guide/perf/fujitsu_pci_pmu.rst
new file mode 100644
index 000000000000..117cefc4d185
--- /dev/null
+++ b/Documentation/admin-guide/perf/fujitsu_pci_pmu.rst
@@ -0,0 +1,50 @@
+====================================================
+Fujitsu Uncore PCI Performance Monitoring Unit (PMU)
+====================================================
+
+This driver supports the Uncore PCI PMUs found in Fujitsu chips.
+Each PCI PMU on these chips is exposed as a uncore perf PMU with device name
+pci_iod<iod>_pci<pci>.
+
+The driver provides a description of its available events and configuration
+options in sysfs, see /sys/bus/event_sources/devices/pci_iod<iod>_pci<pci>/.
+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 pci_iod0_pci0/event=0x24/ 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:
+- pci-port0-cycles
+  This event counts PCI cycles at PCI frequency in port0.
+- pci-port0-read-count
+  This event counts read transactions for data transfer in port0.
+- pci-port0-read-count-bus
+  This event counts read transactions for bus usage in port0.
+- pci-port0-write-count
+  This event counts write transactions for data transfer in port0.
+- pci-port0-write-count-bus
+  This event counts write transactions for bus usage in port0.
+- pci-port1-cycles
+  This event counts PCI cycles at PCI frequency in port1.
+- pci-port1-read-count
+  This event counts read transactions for data transfer in port1.
+- pci-port1-read-count-bus
+  This event counts read transactions for bus usage in port1.
+- pci-port1-write-count
+  This event counts write transactions for data transfer in port1.
+- pci-port1-write-count-bus
+  This event counts write transactions for bus usage in port1.
+- ea-pci
+  This event counts energy consumption of PCI.
+
+  'ea' is the abbreviation for 'Energy Analyzer'.
+
+Examples for use with perf::
+
+  perf stat -e pci_iod0_pci0/ea-pci/ 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/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
index e0262060db17..50cc039ad702 100644
--- a/Documentation/admin-guide/perf/index.rst
+++ b/Documentation/admin-guide/perf/index.rst
@@ -30,3 +30,4 @@ Performance monitor support
    ampere_cspmu
    mrvl-pem-pmu
    fujitsu_mac_pmu
+   fujitsu_pci_pmu
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 269bf72a512a..f8084fe2ccaf 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -187,6 +187,15 @@ config FUJITSU_MAC_PMU
 	 Adds the Uncore MAC PMU into the perf events subsystem for
 	 monitoring Uncore MAC events.
 
+config FUJITSU_PCI_PMU
+	bool "Fujitsu Uncore PCI PMU"
+	depends on (ARM64 && (ACPI || COMPILE_TEST))
+	help
+	 Provides support for the Uncore PCI performance monitor unit (PMU)
+	 in Fujitsu processors.
+	 Adds the Uncore PCI PMU into the perf events subsystem for
+	 monitoring Uncore PCI events.
+
 config QCOM_L2_PMU
 	bool "Qualcomm Technologies L2-cache PMU"
 	depends on ARCH_QCOM && ARM64 && ACPI
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index c9a2ba78d34f..30717ebb4801 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_FSL_IMX8_DDR_PMU) += fsl_imx8_ddr_perf.o
 obj-$(CONFIG_FSL_IMX9_DDR_PMU) += fsl_imx9_ddr_perf.o
 obj-$(CONFIG_HISI_PMU) += hisilicon/
 obj-$(CONFIG_FUJITSU_MAC_PMU) += fujitsu_mac_pmu.o
+obj-$(CONFIG_FUJITSU_PCI_PMU) += fujitsu_pci_pmu.o
 obj-$(CONFIG_QCOM_L2_PMU)	+= qcom_l2_pmu.o
 obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
 obj-$(CONFIG_RISCV_PMU) += riscv_pmu.o
diff --git a/drivers/perf/fujitsu_pci_pmu.c b/drivers/perf/fujitsu_pci_pmu.c
new file mode 100644
index 000000000000..4bb2cfbde10c
--- /dev/null
+++ b/drivers/perf/fujitsu_pci_pmu.c
@@ -0,0 +1,553 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for the Uncore PCI PMUs in Fujitsu chips.
+ *
+ * See Documentation/admin-guide/perf/fujitsu_pci_pmu.rst for more details.
+ *
+ * This driver is based on drivers/perf/qcom_l3_pmu.c
+ * Copyright (c) 2015-2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2024 Fujitsu. All rights reserved.
+ */
+
+#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 PCI_NUM_COUNTERS  8
+/* Mask for the event type field within perf_event_attr.config and EVTYPE reg */
+#define PCI_EVTYPE_MASK   0xFF
+
+/* Perfmon registers */
+#define PCI_PM_EVCNTR(__cntr) (0x000 + (__cntr) * 8)
+#define PCI_PM_CNTCTL(__cntr) (0x100 + (__cntr) * 8)
+#define PCI_PM_EVTYPE(__cntr) (0x200 + (__cntr) * 8)
+#define PCI_PM_CR         0x400
+#define PCI_PM_CNTENSET   0x410
+#define PCI_PM_CNTENCLR   0x418
+#define PCI_PM_INTENSET   0x420
+#define PCI_PM_INTENCLR   0x428
+#define PCI_PM_OVSR       0x440
+
+/* PCI_PM_CNTCTLx */
+#define PMCNT_RESET           0
+
+/* PCI_PM_EVTYPEx */
+#define EVSEL(__val)          FIELD_GET(PCI_EVTYPE_MASK, __val)
+
+/* PCI_PM_CR */
+#define PM_RESET              BIT(1)
+#define PM_ENABLE             BIT(0)
+
+/* PCI_PM_CNTENSET */
+#define PMCNTENSET(__cntr)    BIT(__cntr)
+
+/* PCI_PM_CNTENCLR */
+#define PMCNTENCLR(__cntr)    BIT(__cntr)
+#define PM_CNTENCLR_RESET     0xFF
+
+/* PCI_PM_INTENSET */
+#define PMINTENSET(__cntr)    BIT(__cntr)
+
+/* PCI_PM_INTENCLR */
+#define PMINTENCLR(__cntr)    BIT(__cntr)
+#define PM_INTENCLR_RESET     0xFF
+
+/* PCI_PM_OVSR */
+#define PMOVSRCLR(__cntr)     BIT(__cntr)
+#define PMOVSRCLR_RESET       0xFF
+
+#define PCI_EVENT_PORT0_CYCLES		0x000
+#define PCI_EVENT_PORT0_READ_COUNT	0x010
+#define PCI_EVENT_PORT0_READ_COUNT_BUS	0x014
+#define PCI_EVENT_PORT0_WRITE_COUNT	0x020
+#define PCI_EVENT_PORT0_WRITE_COUNT_BUS	0x024
+#define PCI_EVENT_PORT1_CYCLES		0x040
+#define PCI_EVENT_PORT1_READ_COUNT	0x050
+#define PCI_EVENT_PORT1_READ_COUNT_BUS	0x054
+#define PCI_EVENT_PORT1_WRITE_COUNT	0x060
+#define PCI_EVENT_PORT1_WRITE_COUNT_BUS	0x064
+#define PCI_EVENT_EA_PCI		0x080
+
+struct pci_pmu {
+	struct pmu		pmu;
+	struct hlist_node	node;
+	void __iomem		*regs;
+	struct perf_event	*events[PCI_NUM_COUNTERS];
+	unsigned long		used_mask[BITS_TO_LONGS(PCI_NUM_COUNTERS)];
+	cpumask_t		cpumask;
+};
+
+static int pci_pmu_cpuhp_state;
+
+#define to_pci_pmu(p) (container_of(p, struct pci_pmu, pmu))
+
+static void fujitsu_pci_counter_start(struct perf_event *event)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(event->pmu);
+	int idx = event->hw.idx;
+
+	/* Initialize the hardware counter and reset prev_count*/
+	local64_set(&event->hw.prev_count, 0);
+	writeq_relaxed(0, pcipmu->regs + PCI_PM_EVCNTR(idx));
+
+	/* Set the event type */
+	writeq_relaxed(EVSEL(event->attr.config), pcipmu->regs + PCI_PM_EVTYPE(idx));
+
+	/* Enable interrupt generation by this counter */
+	writeq_relaxed(PMINTENSET(idx), pcipmu->regs + PCI_PM_INTENSET);
+
+	/* Finally, enable the counter */
+	writeq_relaxed(PMCNT_RESET, pcipmu->regs + PCI_PM_CNTCTL(idx));
+	writeq_relaxed(PMCNTENSET(idx), pcipmu->regs + PCI_PM_CNTENSET);
+}
+
+static void fujitsu_pci_counter_stop(struct perf_event *event,
+					      int flags)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(event->pmu);
+	int idx = event->hw.idx;
+
+	/* Disable the counter */
+	writeq_relaxed(PMCNTENCLR(idx), pcipmu->regs + PCI_PM_CNTENCLR);
+
+	/* Disable interrupt generation by this counter */
+	writeq_relaxed(PMINTENCLR(idx), pcipmu->regs + PCI_PM_INTENCLR);
+}
+
+static void fujitsu_pci_counter_update(struct perf_event *event)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(event->pmu);
+	int idx = event->hw.idx;
+	u64 prev, new;
+
+	do {
+		prev = local64_read(&event->hw.prev_count);
+		new = readq_relaxed(pcipmu->regs + PCI_PM_EVCNTR(idx));
+	} while (local64_cmpxchg(&event->hw.prev_count, prev, new) != prev);
+
+	local64_add(new - prev, &event->count);
+}
+
+static inline void fujitsu_pci__init(struct pci_pmu *pcipmu)
+{
+	int i;
+
+	writeq_relaxed(PM_RESET, pcipmu->regs + PCI_PM_CR);
+
+	writeq_relaxed(PM_CNTENCLR_RESET, pcipmu->regs + PCI_PM_CNTENCLR);
+	writeq_relaxed(PM_INTENCLR_RESET, pcipmu->regs + PCI_PM_INTENCLR);
+	writeq_relaxed(PMOVSRCLR_RESET, pcipmu->regs + PCI_PM_OVSR);
+
+	for (i = 0; i < PCI_NUM_COUNTERS; ++i) {
+		writeq_relaxed(PMCNT_RESET, pcipmu->regs + PCI_PM_CNTCTL(i));
+		writeq_relaxed(EVSEL(0), pcipmu->regs + PCI_PM_EVTYPE(i));
+	}
+
+	/*
+	 * Use writeq here to ensure all programming commands are done
+	 * before proceeding
+	 */
+	writeq(PM_ENABLE, pcipmu->regs + PCI_PM_CR);
+}
+
+static irqreturn_t fujitsu_pci__handle_irq(int irq_num, void *data)
+{
+	struct pci_pmu *pcipmu = data;
+	/* Read the overflow status register */
+	long status = readq_relaxed(pcipmu->regs + PCI_PM_OVSR);
+	int idx;
+
+	if (status == 0)
+		return IRQ_NONE;
+
+	/* Clear the bits we read on the overflow status register */
+	writeq_relaxed(status, pcipmu->regs + PCI_PM_OVSR);
+
+	for_each_set_bit(idx, &status, PCI_NUM_COUNTERS) {
+		struct perf_event *event;
+
+		event = pcipmu->events[idx];
+		if (!event)
+			continue;
+
+		fujitsu_pci_counter_update(event);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void fujitsu_pci__pmu_enable(struct pmu *pmu)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(pmu);
+
+	/* Ensure the other programming commands are observed before enabling */
+	wmb();
+
+	writeq_relaxed(PM_ENABLE, pcipmu->regs + PCI_PM_CR);
+}
+
+static void fujitsu_pci__pmu_disable(struct pmu *pmu)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(pmu);
+
+	writeq_relaxed(0, pcipmu->regs + PCI_PM_CR);
+
+	/* Ensure the basic counter unit is stopped before proceeding */
+	wmb();
+}
+
+/*
+ * We must NOT create groups containing events from multiple hardware PMUs,
+ * although mixing different software and hardware PMUs is allowed.
+ */
+static bool fujitsu_pci__validate_event_group(struct perf_event *event)
+{
+	struct perf_event *leader = event->group_leader;
+	struct perf_event *sibling;
+	int counters = 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 <= PCI_NUM_COUNTERS;
+}
+
+static int fujitsu_pci__event_init(struct perf_event *event)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* Is the event for this PMU? */
+	if (event->attr.type != event->pmu->type)
+		return -ENOENT;
+
+	/*
+	 * Sampling not supported since these events are not
+	 * core-attributable.
+	 */
+	if (hwc->sample_period)
+		return -EINVAL;
+
+	/*
+	 * Task mode not available, we run the counters as socket counters,
+	 * not attributable to any CPU and therefore cannot attribute per-task.
+	 */
+	if (event->cpu < 0)
+		return -EINVAL;
+
+	/* Validate the group */
+	if (!fujitsu_pci__validate_event_group(event))
+		return -EINVAL;
+
+	hwc->idx = -1;
+
+	/*
+	 * Many perf core operations (eg. events rotation) operate on a
+	 * single CPU context. This is obvious for CPU PMUs, where one
+	 * expects the same sets of events being observed on all CPUs,
+	 * but can lead to issues for off-core PMUs, like this one, where
+	 * each event could be theoretically assigned to a different CPU.
+	 * To mitigate this, we enforce CPU assignment to one designated
+	 * processor (the one described in the "cpumask" attribute exported
+	 * by the PMU device). perf user space tools honor this and avoid
+	 * opening more than one copy of the events.
+	 */
+	event->cpu = cpumask_first(&pcipmu->cpumask);
+
+	return 0;
+}
+
+static void fujitsu_pci__event_start(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	hwc->state = 0;
+	fujitsu_pci_counter_start(event);
+}
+
+static void fujitsu_pci__event_stop(struct perf_event *event, int flags)
+{
+	struct hw_perf_event *hwc = &event->hw;
+
+	if (hwc->state & PERF_HES_STOPPED)
+		return;
+
+	fujitsu_pci_counter_stop(event, flags);
+	if (flags & PERF_EF_UPDATE)
+		fujitsu_pci_counter_update(event);
+	hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int fujitsu_pci__event_add(struct perf_event *event, int flags)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+	int idx;
+
+	/* Try to allocate a counter. */
+	idx = bitmap_find_free_region(pcipmu->used_mask, PCI_NUM_COUNTERS, 0);
+	if (idx < 0)
+		/* The counters are all in use. */
+		return -EAGAIN;
+
+	hwc->idx = idx;
+	hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+	pcipmu->events[idx] = event;
+
+	if (flags & PERF_EF_START)
+		fujitsu_pci__event_start(event, 0);
+
+	/* Propagate changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+
+	return 0;
+}
+
+static void fujitsu_pci__event_del(struct perf_event *event, int flags)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(event->pmu);
+	struct hw_perf_event *hwc = &event->hw;
+
+	/* Stop and clean up */
+	fujitsu_pci__event_stop(event, flags | PERF_EF_UPDATE);
+	pcipmu->events[hwc->idx] = NULL;
+	bitmap_release_region(pcipmu->used_mask, hwc->idx, 0);
+
+	/* Propagate changes to the userspace mapping. */
+	perf_event_update_userpage(event);
+}
+
+static void fujitsu_pci__event_read(struct perf_event *event)
+{
+	fujitsu_pci_counter_update(event);
+}
+
+#define PCI_PMU_FORMAT_ATTR(_name, _config)				      \
+	(&((struct dev_ext_attribute[]) {				      \
+		{ .attr = __ATTR(_name, 0444, device_show_string, NULL),      \
+		  .var = (void *) _config, }				      \
+	})[0].attr.attr)
+
+static struct attribute *fujitsu_pci_pmu_formats[] = {
+	PCI_PMU_FORMAT_ATTR(event, "config:0-7"),
+	NULL
+};
+
+static const struct attribute_group fujitsu_pci_pmu_format_group = {
+	.name = "format",
+	.attrs = fujitsu_pci_pmu_formats,
+};
+
+static ssize_t pci_pmu_event_show(struct device *dev,
+				     struct device_attribute *attr, char *page)
+{
+	struct perf_pmu_events_attr *pmu_attr;
+
+	pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
+	return sysfs_emit(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+#define PCI_EVENT_ATTR(_name, _id)					     \
+	PMU_EVENT_ATTR_ID(_name, pci_pmu_event_show, _id)
+
+static struct attribute *fujitsu_pci_pmu_events[] = {
+	PCI_EVENT_ATTR(pci-port0-cycles, PCI_EVENT_PORT0_CYCLES),
+	PCI_EVENT_ATTR(pci-port0-read-count, PCI_EVENT_PORT0_READ_COUNT),
+	PCI_EVENT_ATTR(pci-port0-read-count-bus, PCI_EVENT_PORT0_READ_COUNT_BUS),
+	PCI_EVENT_ATTR(pci-port0-write-count, PCI_EVENT_PORT0_WRITE_COUNT),
+	PCI_EVENT_ATTR(pci-port0-write-count-bus, PCI_EVENT_PORT0_WRITE_COUNT_BUS),
+	PCI_EVENT_ATTR(pci-port1-cycles, PCI_EVENT_PORT1_CYCLES),
+	PCI_EVENT_ATTR(pci-port1-read-count, PCI_EVENT_PORT1_READ_COUNT),
+	PCI_EVENT_ATTR(pci-port1-read-count-bus, PCI_EVENT_PORT1_READ_COUNT_BUS),
+	PCI_EVENT_ATTR(pci-port1-write-count, PCI_EVENT_PORT1_WRITE_COUNT),
+	PCI_EVENT_ATTR(pci-port1-write-count-bus, PCI_EVENT_PORT1_WRITE_COUNT_BUS),
+	PCI_EVENT_ATTR(ea-pci, PCI_EVENT_EA_PCI),
+	NULL
+};
+
+static const struct attribute_group fujitsu_pci_pmu_events_group = {
+	.name = "events",
+	.attrs = fujitsu_pci_pmu_events,
+};
+
+static ssize_t cpumask_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct pci_pmu *pcipmu = to_pci_pmu(dev_get_drvdata(dev));
+
+	return cpumap_print_to_pagebuf(true, buf, &pcipmu->cpumask);
+}
+static DEVICE_ATTR_RO(cpumask);
+
+static struct attribute *fujitsu_pci_pmu_cpumask_attrs[] = {
+	&dev_attr_cpumask.attr,
+	NULL
+};
+
+static const struct attribute_group fujitsu_pci_pmu_cpumask_attr_group = {
+	.attrs = fujitsu_pci_pmu_cpumask_attrs,
+};
+
+static const struct attribute_group *fujitsu_pci_pmu_attr_grps[] = {
+	&fujitsu_pci_pmu_format_group,
+	&fujitsu_pci_pmu_events_group,
+	&fujitsu_pci_pmu_cpumask_attr_group,
+	NULL
+};
+
+static int fujitsu_pci_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct pci_pmu *pcipmu = hlist_entry_safe(node, struct pci_pmu, node);
+
+	/* If there is not a CPU/PMU association pick this CPU */
+	if (cpumask_empty(&pcipmu->cpumask))
+		cpumask_set_cpu(cpu, &pcipmu->cpumask);
+
+	return 0;
+}
+
+static int fujitsu_pci_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+	struct pci_pmu *pcipmu = hlist_entry_safe(node, struct pci_pmu, node);
+	unsigned int target;
+
+	if (!cpumask_test_and_clear_cpu(cpu, &pcipmu->cpumask))
+		return 0;
+
+	target = cpumask_any_but(cpu_online_mask, cpu);
+	if (target >= nr_cpu_ids)
+		return 0;
+
+	perf_pmu_migrate_context(&pcipmu->pmu, cpu, target);
+	cpumask_set_cpu(target, &pcipmu->cpumask);
+
+	return 0;
+}
+
+static int fujitsu_pci_pmu_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct acpi_device *acpi_dev;
+	struct pci_pmu *pcipmu;
+	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");
+
+	pcipmu = devm_kzalloc(dev, sizeof(*pcipmu), GFP_KERNEL);
+	if (!pcipmu)
+		return -ENOMEM;
+
+	name = devm_kasprintf(dev, GFP_KERNEL, "pci_iod%llu_pci%llu",
+			  (uid >> 4) & 0xF, uid & 0xF);
+	if (!name)
+		return -ENOMEM;
+
+	pcipmu->pmu = (struct pmu) {
+		.parent		= dev,
+		.task_ctx_nr	= perf_invalid_context,
+
+		.pmu_enable	= fujitsu_pci__pmu_enable,
+		.pmu_disable	= fujitsu_pci__pmu_disable,
+		.event_init	= fujitsu_pci__event_init,
+		.add		= fujitsu_pci__event_add,
+		.del		= fujitsu_pci__event_del,
+		.start		= fujitsu_pci__event_start,
+		.stop		= fujitsu_pci__event_stop,
+		.read		= fujitsu_pci__event_read,
+
+		.attr_groups	= fujitsu_pci_pmu_attr_grps,
+		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
+	};
+
+	pcipmu->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &memrc);
+	if (IS_ERR(pcipmu->regs))
+		return PTR_ERR(pcipmu->regs);
+
+	fujitsu_pci__init(pcipmu);
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_request_irq(dev, ret, fujitsu_pci__handle_irq, 0,
+						   name, pcipmu);
+	if (ret)
+		return dev_err_probe(dev, ret, "Request for IRQ failed for slice @%pa\n",
+							 &memrc->start);
+
+	/* Add this instance to the list used by the offline callback */
+	ret = cpuhp_state_add_instance(pci_pmu_cpuhp_state, &pcipmu->node);
+	if (ret)
+		return dev_err_probe(dev, ret, "Error registering hotplug");
+
+	ret = perf_pmu_register(&pcipmu->pmu, name, -1);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to register PCI PMU\n");
+
+	dev_dbg(dev, "Registered %s, type: %d\n", name, pcipmu->pmu.type);
+
+	return 0;
+}
+
+static const struct acpi_device_id fujitsu_pci_pmu_acpi_match[] = {
+	{ "FUJI200D", },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, fujitsu_pci_pmu_acpi_match);
+
+static struct platform_driver fujitsu_pci_pmu_driver = {
+	.driver = {
+		.name = "fujitsu-pci-pmu",
+		.acpi_match_table = fujitsu_pci_pmu_acpi_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe = fujitsu_pci_pmu_probe,
+};
+
+static int __init register_fujitsu_pci_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/pci:online",
+				      fujitsu_pci_pmu_online_cpu,
+				      fujitsu_pci_pmu_offline_cpu);
+	if (ret < 0)
+		return ret;
+
+	pci_pmu_cpuhp_state = ret;
+	return platform_driver_register(&fujitsu_pci_pmu_driver);
+}
+device_initcall(register_fujitsu_pci_pmu_driver);
-- 
2.43.0

Re: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Peter Zijlstra]

On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> +	pcipmu->pmu = (struct pmu) {
> +		.parent		= dev,
> +		.task_ctx_nr	= perf_invalid_context,
> +
> +		.pmu_enable	= fujitsu_pci__pmu_enable,
> +		.pmu_disable	= fujitsu_pci__pmu_disable,
> +		.event_init	= fujitsu_pci__event_init,
> +		.add		= fujitsu_pci__event_add,
> +		.del		= fujitsu_pci__event_del,
> +		.start		= fujitsu_pci__event_start,
> +		.stop		= fujitsu_pci__event_stop,
> +		.read		= fujitsu_pci__event_read,
> +
> +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,

Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
being uncore they cannot generate samples.

> +	};

Re: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Mark Rutland]

On Tue, Jun 17, 2025 at 12:36:18PM +0200, Peter Zijlstra wrote:
> On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> > +	pcipmu->pmu = (struct pmu) {
> > +		.parent		= dev,
> > +		.task_ctx_nr	= perf_invalid_context,
> > +
> > +		.pmu_enable	= fujitsu_pci__pmu_enable,
> > +		.pmu_disable	= fujitsu_pci__pmu_disable,
> > +		.event_init	= fujitsu_pci__event_init,
> > +		.add		= fujitsu_pci__event_add,
> > +		.del		= fujitsu_pci__event_del,
> > +		.start		= fujitsu_pci__event_start,
> > +		.stop		= fujitsu_pci__event_stop,
> > +		.read		= fujitsu_pci__event_read,
> > +
> > +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> > +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> 
> Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
> being uncore they cannot generate samples.

These PMUs actually have an interrupt, so that might be a bit confusing.
That said, the counters seem to be 64-bit, so the interrupt doesn't seem
practically necessary today.

Either way, the fujitsu_pci__event_init() function rejects sampling
events, so it correctly rejects sampling events.

IMO, it'd be a bit nicer to do the inverse, and have the perf core
reject sampling events by default for non-CPU PMUs.

Mark.

Re: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Peter Zijlstra]

On Thu, Jun 19, 2025 at 02:57:55PM +0100, Mark Rutland wrote:
> On Tue, Jun 17, 2025 at 12:36:18PM +0200, Peter Zijlstra wrote:
> > On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> > > +	pcipmu->pmu = (struct pmu) {
> > > +		.parent		= dev,
> > > +		.task_ctx_nr	= perf_invalid_context,
> > > +
> > > +		.pmu_enable	= fujitsu_pci__pmu_enable,
> > > +		.pmu_disable	= fujitsu_pci__pmu_disable,
> > > +		.event_init	= fujitsu_pci__event_init,
> > > +		.add		= fujitsu_pci__event_add,
> > > +		.del		= fujitsu_pci__event_del,
> > > +		.start		= fujitsu_pci__event_start,
> > > +		.stop		= fujitsu_pci__event_stop,
> > > +		.read		= fujitsu_pci__event_read,
> > > +
> > > +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> > > +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> > 
> > Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
> > being uncore they cannot generate samples.
> 
> These PMUs actually have an interrupt, so that might be a bit confusing.
> That said, the counters seem to be 64-bit, so the interrupt doesn't seem
> practically necessary today.

Yeah, I saw they had an interrupt. But them being uncore they must not
sample, and NO_INTERRUPT means not being able to sample.

Naming urgh :-)

> Either way, the fujitsu_pci__event_init() function rejects sampling
> events, so it correctly rejects sampling events.
> 
> IMO, it'd be a bit nicer to do the inverse, and have the perf core
> reject sampling events by default for non-CPU PMUs.

Yeah, there's lots of cleanup to be done. Quite possibly also some
unification between the various drivers.

Just need someone that knows what they're doing that has spare time,
know anybody like that? :-)

Re: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Mark Rutland]

On Thu, Jun 19, 2025 at 04:04:42PM +0200, Peter Zijlstra wrote:
> On Thu, Jun 19, 2025 at 02:57:55PM +0100, Mark Rutland wrote:
> > On Tue, Jun 17, 2025 at 12:36:18PM +0200, Peter Zijlstra wrote:
> > > On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> > > > +	pcipmu->pmu = (struct pmu) {
> > > > +		.parent		= dev,
> > > > +		.task_ctx_nr	= perf_invalid_context,
> > > > +
> > > > +		.pmu_enable	= fujitsu_pci__pmu_enable,
> > > > +		.pmu_disable	= fujitsu_pci__pmu_disable,
> > > > +		.event_init	= fujitsu_pci__event_init,
> > > > +		.add		= fujitsu_pci__event_add,
> > > > +		.del		= fujitsu_pci__event_del,
> > > > +		.start		= fujitsu_pci__event_start,
> > > > +		.stop		= fujitsu_pci__event_stop,
> > > > +		.read		= fujitsu_pci__event_read,
> > > > +
> > > > +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> > > > +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> > > 
> > > Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
> > > being uncore they cannot generate samples.
> > 
> > These PMUs actually have an interrupt, so that might be a bit confusing.
> > That said, the counters seem to be 64-bit, so the interrupt doesn't seem
> > practically necessary today.
> 
> Yeah, I saw they had an interrupt. But them being uncore they must not
> sample, and NO_INTERRUPT means not being able to sample.
> 
> Naming urgh :-)

Yeah :)

FWIW, that came to mind due to:

  https://lore.kernel.org/lkml/20250618-perf-pmu-cap-docs-v1-1-0d34387d6e47@collabora.com/

... and if NO_INTERRUPT would be better-named as NO_SAMPLING, that might
be a good opportunity to clean that up.

> > Either way, the fujitsu_pci__event_init() function rejects sampling
> > events, so it correctly rejects sampling events.
> > 
> > IMO, it'd be a bit nicer to do the inverse, and have the perf core
> > reject sampling events by default for non-CPU PMUs.
> 
> Yeah, there's lots of cleanup to be done. Quite possibly also some
> unification between the various drivers.
> 
> Just need someone that knows what they're doing that has spare time,
> know anybody like that? :-)

I think a few folk likle that live in the nearest hall of mirrors...

If you're happy with that in concept, I can see about getting someone to
look at that -- the general idea has come up a few times.

Mark.

Re: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Peter Zijlstra]

On Thu, Jun 19, 2025 at 03:36:04PM +0100, Mark Rutland wrote:
> On Thu, Jun 19, 2025 at 04:04:42PM +0200, Peter Zijlstra wrote:
> > On Thu, Jun 19, 2025 at 02:57:55PM +0100, Mark Rutland wrote:
> > > On Tue, Jun 17, 2025 at 12:36:18PM +0200, Peter Zijlstra wrote:
> > > > On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> > > > > +	pcipmu->pmu = (struct pmu) {
> > > > > +		.parent		= dev,
> > > > > +		.task_ctx_nr	= perf_invalid_context,
> > > > > +
> > > > > +		.pmu_enable	= fujitsu_pci__pmu_enable,
> > > > > +		.pmu_disable	= fujitsu_pci__pmu_disable,
> > > > > +		.event_init	= fujitsu_pci__event_init,
> > > > > +		.add		= fujitsu_pci__event_add,
> > > > > +		.del		= fujitsu_pci__event_del,
> > > > > +		.start		= fujitsu_pci__event_start,
> > > > > +		.stop		= fujitsu_pci__event_stop,
> > > > > +		.read		= fujitsu_pci__event_read,
> > > > > +
> > > > > +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> > > > > +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> > > > 
> > > > Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
> > > > being uncore they cannot generate samples.
> > > 
> > > These PMUs actually have an interrupt, so that might be a bit confusing.
> > > That said, the counters seem to be 64-bit, so the interrupt doesn't seem
> > > practically necessary today.
> > 
> > Yeah, I saw they had an interrupt. But them being uncore they must not
> > sample, and NO_INTERRUPT means not being able to sample.
> > 
> > Naming urgh :-)
> 
> Yeah :)
> 
> FWIW, that came to mind due to:
> 
>   https://lore.kernel.org/lkml/20250618-perf-pmu-cap-docs-v1-1-0d34387d6e47@collabora.com/

Oh hey, look at that.. Clearly that is still stuck in my unread pile :/

> ... and if NO_INTERRUPT would be better-named as NO_SAMPLING, that might
> be a good opportunity to clean that up.

Yeah, that's more or less what it does, look at the few sites in
perf/events/core.c that test it.

> > Yeah, there's lots of cleanup to be done. Quite possibly also some
> > unification between the various drivers.
> > 
> > Just need someone that knows what they're doing that has spare time,
> > know anybody like that? :-)
> 
> I think a few folk likle that live in the nearest hall of mirrors...
> 
> If you're happy with that in concept, I can see about getting someone to
> look at that -- the general idea has come up a few times.

Sure.

RE: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Koichi Okuno (Fujitsu)]

Hi, Peter

Sorry for the late reply.

> On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> > +	pcipmu->pmu = (struct pmu) {
> > +		.parent		= dev,
> > +		.task_ctx_nr	= perf_invalid_context,
> > +
> > +		.pmu_enable	= fujitsu_pci__pmu_enable,
> > +		.pmu_disable	= fujitsu_pci__pmu_disable,
> > +		.event_init	= fujitsu_pci__event_init,
> > +		.add		= fujitsu_pci__event_add,
> > +		.del		= fujitsu_pci__event_del,
> > +		.start		= fujitsu_pci__event_start,
> > +		.stop		= fujitsu_pci__event_stop,
> > +		.read		= fujitsu_pci__event_read,
> > +
> > > +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> > +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> 
> Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
> being uncore they cannot generate samples.

Even now, the fujitsu_pci__event_init() function rejects sampling events
before checking PERF_PMU_CAP_NO_INTERRUPT in core.c.
However, I think it is correct to have PERF_PMU_CAP_NO_INTERRUPT which
means not being able to sample, so I will add NO_INTERRUPT in the next
version.

Best Regards,
Koichi Okuno

Re: [PATCH v5 2/2] perf: Fujitsu: Add the Uncore PCI PMU driver

[Mark Rutland]

On Tue, Jul 01, 2025 at 06:13:57AM +0000, Koichi Okuno (Fujitsu) wrote:
> Hi, Peter
> 
> Sorry for the late reply.
> 
> > On Tue, Jun 17, 2025 at 07:27:50PM +0900, Koichi Okuno wrote:
> > > +	pcipmu->pmu = (struct pmu) {
> > > +		.parent		= dev,
> > > +		.task_ctx_nr	= perf_invalid_context,
> > > +
> > > +		.pmu_enable	= fujitsu_pci__pmu_enable,
> > > +		.pmu_disable	= fujitsu_pci__pmu_disable,
> > > +		.event_init	= fujitsu_pci__event_init,
> > > +		.add		= fujitsu_pci__event_add,
> > > +		.del		= fujitsu_pci__event_del,
> > > +		.start		= fujitsu_pci__event_start,
> > > +		.stop		= fujitsu_pci__event_stop,
> > > +		.read		= fujitsu_pci__event_read,
> > > +
> > > > +		.attr_groups	= fujitsu_pci_pmu_attr_grps,
> > > +		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
> > 
> > Should these drivers not also have PERF_PMU_CAP_NO_INTERRUPT ? Per them
> > being uncore they cannot generate samples.
> 
> Even now, the fujitsu_pci__event_init() function rejects sampling events
> before checking PERF_PMU_CAP_NO_INTERRUPT in core.c.
> However, I think it is correct to have PERF_PMU_CAP_NO_INTERRUPT which
> means not being able to sample, so I will add NO_INTERRUPT in the next
> version.

Sorry to give contradictory feeback, but given that the majority of PMU
drivers under drivers/perf/ don't set PERF_PMU_CAP_NO_INTERRUPT, and
explicitly reject sampling events, I'd prefer to do the same for
consistency.

Peter, are you happy with that for now?

Overall it would be better for PMUs to export a positive "I support
sampling" flag, and maybe rename/replace PERF_PMU_CAP_NO_INTERRUPT
accordingly, which I'd be happy to look at in future.

Mark.