* [PATCH 2/3] perf: Add Broadcom BCM5301X AXI Trace Module counters
2026-10-26 21:11 [PATCH 0/3] Support for BCM5301X AXI trace PMUs Florian Fainelli
2026-10-26 21:11 ` [PATCH 1/3] dt-bindings: perf: Describe the Broadcom BCM5301X AXI PMU Florian Fainelli
@ 2026-10-26 21:11 ` Florian Fainelli
2026-10-26 21:11 ` [PATCH 3/3] ARM: dts: BCM5301X: Enable AXI PMUs Florian Fainelli
2 siblings, 0 replies; 4+ messages in thread
From: Florian Fainelli @ 2026-10-26 21:11 UTC (permalink / raw)
To: linux-kernel
Cc: Florian Fainelli, Hauke Mehrtens, Rafał Miłecki,
Broadcom internal kernel review list, Jonathan Corbet,
Shuah Khan, Randy Dunlap, Will Deacon, Mark Rutland, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Besar Wicaksono,
Ilkka Koskinen,
moderated list:BROADCOM BCM5301X ARM ARCHITECTURE,
open list:DOCUMENTATION,
open list:ARM PMU PROFILING AND DEBUGGING,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS
Expose unfiltered fixed counters through system-wide perf events. Keep
hardware free-running and use per-event baselines, locking, and periodic
32-bit delta accounting without resetting concurrent measurements.
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
.../admin-guide/perf/bcm5301x-axi-pmu.rst | 92 ++++
Documentation/admin-guide/perf/index.rst | 1 +
MAINTAINERS | 2 +
drivers/perf/Kconfig | 12 +
drivers/perf/Makefile | 1 +
drivers/perf/bcm5301x_axi_pmu.c | 450 ++++++++++++++++++
6 files changed, 558 insertions(+)
create mode 100644 Documentation/admin-guide/perf/bcm5301x-axi-pmu.rst
create mode 100644 drivers/perf/bcm5301x_axi_pmu.c
diff --git a/Documentation/admin-guide/perf/bcm5301x-axi-pmu.rst b/Documentation/admin-guide/perf/bcm5301x-axi-pmu.rst
new file mode 100644
index 000000000000..720f042dfbd0
--- /dev/null
+++ b/Documentation/admin-guide/perf/bcm5301x-axi-pmu.rst
@@ -0,0 +1,92 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Broadcom BCM5301X AXI Trace Module PMU
+====================================
+
+The BCM5301X AXI Trace Modules observe the two PL310 master interfaces and
+the Accelerator Coherency Port (ACP). Each instance registers a PMU named
+``bcm5301x_axi_<physical-base>``, for example ``bcm5301x_axi_19003000`` for
+PL310 M0, ``bcm5301x_axi_19004000`` for PL310 M1, and
+``bcm5301x_axi_19007000`` for ACP.
+
+Enable CONFIG_PERF_EVENTS and CONFIG_BCM5301X_AXI_PMU and provide an enabled
+device-tree node for each instance. Load ``bcm5301x_axi_pmu`` if built as a
+module. The driver owns the module exclusively; firmware or debug tools
+must not change its configuration while the driver is bound.
+
+Events and scope
+----------------
+
+The ``events`` and ``format`` directories under
+``/sys/bus/event_source/devices/bcm5301x_axi_*`` describe the ABI. Event IDs
+0 through 15 select fixed counters:
+
+==== ====================================
+ID Event
+==== ====================================
+0 write_commands
+1 read_commands
+2 write_address_cycles
+3 read_address_cycles
+4 write_data_cycles
+5 read_data_cycles
+6 write_response_cycles
+7 write_address_stall_cycles
+8 read_address_stall_cycles
+9 write_data_stall_cycles
+10 read_data_stall_cycles
+11 write_response_stall_cycles
+12 write_beats
+13 read_beats
+14 write_outstanding_cycles
+15 read_outstanding_cycles
+==== ====================================
+
+Active channel cycles count VALID asserted; stall cycles count VALID
+asserted while READY is deasserted. Outstanding cycles count cycles with
+more than zero outstanding commands. These are cycle counts, not the sum
+of outstanding requests. Counts cover all traffic at the observed port;
+PL310 hits do not necessarily generate traffic at its master interfaces.
+ACP can remain idle unless an accelerator uses that interface.
+
+All measurements are unfiltered and system-wide. The ``cpumask`` file
+identifies the CPU managing each PMU, not a CPU traffic filter. Per-task
+counting, privilege exclusions, sampling, configurable AXI filters,
+latency measurements, and ATB transaction trace capture are unsupported.
+Beat counts are reported as beats, without assuming a byte conversion.
+
+Each fixed counter can be allocated once at a time. Duplicate requests
+in a single group are rejected; separate events can be multiplexed by
+perf. Different counters on one PMU can run together. Groups spanning
+different hardware PMUs are rejected.
+
+The hardware counters run continuously while the driver is bound, with
+per-event baselines excluding periods when an event is stopped. Starting
+one event does not reset another event's hardware counter. There is no
+overflow interrupt. A timer extends the wrapping 32-bit counters to 64 bits
+every 100 ms while events run. At 500 MHz a counter incrementing once per
+cycle wraps in about 8.6 seconds. Accuracy requires servicing the timer
+before a full wrap; long interrupt stalls and suspend intervals can lose
+counts. Stop measurements before suspending the system.
+
+Testing
+-------
+
+Check discovery and count commands and beats over a memory workload::
+
+ modprobe bcm5301x_axi_pmu
+ ls /sys/bus/event_source/devices/bcm5301x_axi_*
+ perf list | grep bcm5301x_axi
+ perf stat -a -e '{bcm5301x_axi_19003000/read_commands/,bcm5301x_axi_19003000/read_beats/}' -- sleep 10
+
+Repeat during a workload whose working set exceeds the PL310 cache, such
+as a memory stress test. Compare with idle, test M1 separately, and expect
+ACP activity only with an ACP user. Network DMA traffic alone need not
+cross the monitored PL310 ports. Use ``perf stat -a -I 1000`` for interval
+counts and run for at least a minute under load to exercise counter wrap.
+
+Check that adding or removing a second, different counter leaves the first
+counter accumulating. Two requests for the same event in one group must
+fail. ``perf record`` and per-task ``perf stat`` must fail. If CPU hotplug
+is available, offline the CPU listed in ``cpumask`` while counting and
+verify that management moves to another online CPU and counting continues.
diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
index aa12708ddb96..6cf0010a3413 100644
--- a/Documentation/admin-guide/perf/index.rst
+++ b/Documentation/admin-guide/perf/index.rst
@@ -31,3 +31,4 @@ Performance monitor support
ampere_cspmu
mrvl-pem-pmu
fujitsu_uncore_pmu
+ bcm5301x-axi-pmu
diff --git a/MAINTAINERS b/MAINTAINERS
index b97f22107fbf..460725721bc8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5220,12 +5220,14 @@ M: Rafał Miłecki <zajec5@gmail.com>
R: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
S: Maintained
+F: Documentation/admin-guide/perf/bcm5301x-axi-pmu.rst
F: Documentation/devicetree/bindings/perf/brcm,bcm5301x-axi-pmu.yaml
F: arch/arm/boot/dts/broadcom/bcm-ns.dtsi
F: arch/arm/boot/dts/broadcom/bcm470*
F: arch/arm/boot/dts/broadcom/bcm5301*
F: arch/arm/boot/dts/broadcom/bcm953012*
F: arch/arm/mach-bcm/bcm_5301x.c
+F: drivers/perf/bcm5301x_axi_pmu.c
BROADCOM BCM53573 ARM ARCHITECTURE
M: Florian Fainelli <florian.fainelli@broadcom.com>
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 245e7bb763b9..69674cc3f31f 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -6,6 +6,18 @@
menu "Performance monitor support"
depends on PERF_EVENTS
+config BCM5301X_AXI_PMU
+ tristate "Broadcom BCM5301X AXI Trace Module PMU"
+ depends on ARCH_BCM_5301X || COMPILE_TEST
+ depends on OF
+ help
+ Support system-wide perf counting on the BCM5301X AXI Trace Modules
+ monitoring the PL310 master interfaces and ACP. Supports commands,
+ beats, active/stall cycles, and outstanding-command cycles. Sampling
+ and transaction trace capture are not supported.
+
+ If compiled as a module, it will be called bcm5301x_axi_pmu.
+
config ARM_CCI_PMU
tristate "ARM CCI PMU driver"
depends on (ARM && CPU_V7) || ARM64
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index eb8a022dad9a..2a51a963b692 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_BCM5301X_AXI_PMU) += bcm5301x_axi_pmu.o
obj-$(CONFIG_ARM_CCI_PMU) += arm-cci.o
obj-$(CONFIG_ARM_CCN) += arm-ccn.o
obj-$(CONFIG_ARM_CMN) += arm-cmn.o
diff --git a/drivers/perf/bcm5301x_axi_pmu.c b/drivers/perf/bcm5301x_axi_pmu.c
new file mode 100644
index 000000000000..15da137a4085
--- /dev/null
+++ b/drivers/perf/bcm5301x_axi_pmu.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Broadcom BCM5301X AXI Trace Module performance counters. */
+
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/cpuhotplug.h>
+#include <linux/hrtimer.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#define ATM_CONFIG 0x00
+#define ATM_STATUS 0x04
+#define ATM_CMD 0x0c
+#define ATM_CTRL_LOCAL BIT(0)
+#define ATM_CMDS_EN BIT(4)
+#define ATM_BEATS_EN BIT(6)
+#define ATM_BUSY_EN BIT(8)
+#define ATM_OUTS_EN BIT(14)
+#define ATM_COUNT_ENABLE (ATM_CMDS_EN | ATM_BEATS_EN | \
+ ATM_BUSY_EN | ATM_OUTS_EN)
+#define ATM_STATE_ENABLE (BIT(9) | BIT(10) | BIT(11) | BIT(13))
+#define ATM_STATE_MASK GENMASK(13, 9)
+#define ATM_CLEAR 0
+#define ATM_STOP 1
+#define ATM_START 2
+
+/* At most one increment per AXI cycle for the exposed counters. */
+#define ATM_POLL_INTERVAL ms_to_ktime(100)
+#define ATM_NR_COUNTERS 16
+
+static enum cpuhp_state bcm5301x_axi_hp_state;
+
+struct bcm5301x_axi_pmu {
+ struct pmu pmu;
+ void __iomem *base;
+ raw_spinlock_t lock;
+ struct hrtimer timer;
+ struct hlist_node hp_node;
+ struct perf_event *events[ATM_NR_COUNTERS];
+ unsigned int nr_active;
+ int cpu;
+};
+
+/* Event IDs select fixed counters, not programmable event selectors. */
+static const u16 bcm5301x_axi_offsets[ATM_NR_COUNTERS] = {
+ 0x10, 0x14, 0x18, 0x1c, 0x20, 0x24, 0x28, 0x2c,
+ 0x30, 0x34, 0x38, 0x3c, 0x58, 0x5c, 0x60, 0x64,
+};
+
+#define ATM_EVENT(_name, _id) \
+ static struct perf_pmu_events_attr event_attr_##_name = { \
+ .attr = __ATTR(_name, 0444, perf_event_sysfs_show, NULL), \
+ .id = _id, \
+ .event_str = "event=" __stringify(_id), \
+ }
+
+ATM_EVENT(write_commands, 0);
+ATM_EVENT(read_commands, 1);
+ATM_EVENT(write_address_cycles, 2);
+ATM_EVENT(read_address_cycles, 3);
+ATM_EVENT(write_data_cycles, 4);
+ATM_EVENT(read_data_cycles, 5);
+ATM_EVENT(write_response_cycles, 6);
+ATM_EVENT(write_address_stall_cycles, 7);
+ATM_EVENT(read_address_stall_cycles, 8);
+ATM_EVENT(write_data_stall_cycles, 9);
+ATM_EVENT(read_data_stall_cycles, 10);
+ATM_EVENT(write_response_stall_cycles, 11);
+ATM_EVENT(write_beats, 12);
+ATM_EVENT(read_beats, 13);
+ATM_EVENT(write_outstanding_cycles, 14);
+ATM_EVENT(read_outstanding_cycles, 15);
+
+static struct attribute *bcm5301x_axi_event_attrs[] = {
+ &event_attr_write_commands.attr.attr,
+ &event_attr_read_commands.attr.attr,
+ &event_attr_write_address_cycles.attr.attr,
+ &event_attr_read_address_cycles.attr.attr,
+ &event_attr_write_data_cycles.attr.attr,
+ &event_attr_read_data_cycles.attr.attr,
+ &event_attr_write_response_cycles.attr.attr,
+ &event_attr_write_address_stall_cycles.attr.attr,
+ &event_attr_read_address_stall_cycles.attr.attr,
+ &event_attr_write_data_stall_cycles.attr.attr,
+ &event_attr_read_data_stall_cycles.attr.attr,
+ &event_attr_write_response_stall_cycles.attr.attr,
+ &event_attr_write_beats.attr.attr,
+ &event_attr_read_beats.attr.attr,
+ &event_attr_write_outstanding_cycles.attr.attr,
+ &event_attr_read_outstanding_cycles.attr.attr,
+ NULL,
+};
+
+static const struct attribute_group bcm5301x_axi_events_group = {
+ .name = "events",
+ .attrs = bcm5301x_axi_event_attrs,
+};
+
+PMU_FORMAT_ATTR(event, "config:0-3");
+
+static struct attribute *bcm5301x_axi_format_attrs[] = {
+ &format_attr_event.attr,
+ NULL,
+};
+
+static const struct attribute_group bcm5301x_axi_format_group = {
+ .name = "format",
+ .attrs = bcm5301x_axi_format_attrs,
+};
+
+static struct bcm5301x_axi_pmu *to_axi_pmu(struct pmu *pmu)
+{
+ return container_of(pmu, struct bcm5301x_axi_pmu, pmu);
+}
+
+static ssize_t cpumask_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(dev_get_drvdata(dev));
+
+ return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpumask_of(READ_ONCE(axi->cpu))));
+}
+static DEVICE_ATTR_RO(cpumask);
+
+static struct attribute *bcm5301x_axi_attrs[] = {
+ &dev_attr_cpumask.attr,
+ NULL,
+};
+
+static const struct attribute_group bcm5301x_axi_group = {
+ .attrs = bcm5301x_axi_attrs,
+};
+
+static const struct attribute_group *bcm5301x_axi_attr_groups[] = {
+ &bcm5301x_axi_events_group,
+ &bcm5301x_axi_format_group,
+ &bcm5301x_axi_group,
+ NULL,
+};
+
+static u32 bcm5301x_axi_read_counter(struct bcm5301x_axi_pmu *axi, int idx)
+{
+ return readl(axi->base + bcm5301x_axi_offsets[idx]);
+}
+
+/* All counter state, including prev_count, is serialized by axi->lock. */
+static void bcm5301x_axi_update(struct bcm5301x_axi_pmu *axi,
+ struct perf_event *event)
+{
+ u32 now = bcm5301x_axi_read_counter(axi, event->hw.idx);
+ u32 prev = local64_read(&event->hw.prev_count);
+
+ local64_set(&event->hw.prev_count, now);
+ local64_add((u32)(now - prev), &event->count);
+}
+
+static enum hrtimer_restart bcm5301x_axi_timer(struct hrtimer *timer)
+{
+ struct bcm5301x_axi_pmu *axi = container_of(timer, typeof(*axi), timer);
+ enum hrtimer_restart ret = HRTIMER_NORESTART;
+ unsigned long flags;
+ int i;
+
+ raw_spin_lock_irqsave(&axi->lock, flags);
+ for (i = 0; i < ATM_NR_COUNTERS; i++) {
+ struct perf_event *event = axi->events[i];
+
+ if (event && !(event->hw.state & PERF_HES_STOPPED))
+ bcm5301x_axi_update(axi, event);
+ }
+ if (axi->nr_active) {
+ hrtimer_forward_now(timer, ATM_POLL_INTERVAL);
+ ret = HRTIMER_RESTART;
+ }
+ raw_spin_unlock_irqrestore(&axi->lock, flags);
+
+ return ret;
+}
+
+static int bcm5301x_axi_event_init(struct perf_event *event)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(event->pmu);
+ struct perf_event *sibling, *leader = event->group_leader;
+ unsigned long used = 0;
+
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+ if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK ||
+ event->cpu < 0)
+ return -EOPNOTSUPP;
+ if (event->attr.config >= ATM_NR_COUNTERS || event->attr.config1 ||
+ event->attr.config2)
+ return -EINVAL;
+
+ /* A group cannot allocate the same fixed counter twice. */
+ if (!is_software_event(leader)) {
+ if (leader->pmu != event->pmu)
+ return -EINVAL;
+ __set_bit(leader->attr.config, &used);
+ }
+ for_each_sibling_event(sibling, leader) {
+ if (is_software_event(sibling))
+ continue;
+ if (sibling->pmu != event->pmu ||
+ test_and_set_bit(sibling->attr.config, &used))
+ return -EINVAL;
+ }
+ if (event != leader && test_bit(event->attr.config, &used))
+ return -EINVAL;
+
+ event->cpu = READ_ONCE(axi->cpu);
+ event->hw.idx = -1;
+ return 0;
+}
+
+static void bcm5301x_axi_start(struct perf_event *event, int flags)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(event->pmu);
+ unsigned long irqflags;
+
+ raw_spin_lock_irqsave(&axi->lock, irqflags);
+ if (event->hw.state & PERF_HES_STOPPED) {
+ local64_set(&event->hw.prev_count,
+ bcm5301x_axi_read_counter(axi, event->hw.idx));
+ event->hw.state = 0;
+ /* Unpinned: the timer can migrate when the managing CPU goes offline. */
+ if (!axi->nr_active++)
+ hrtimer_start(&axi->timer, ATM_POLL_INTERVAL, HRTIMER_MODE_REL);
+ }
+ raw_spin_unlock_irqrestore(&axi->lock, irqflags);
+}
+
+static void bcm5301x_axi_stop(struct perf_event *event, int flags)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(event->pmu);
+ unsigned long irqflags;
+
+ raw_spin_lock_irqsave(&axi->lock, irqflags);
+ if (!(event->hw.state & PERF_HES_STOPPED)) {
+ bcm5301x_axi_update(axi, event);
+ event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ axi->nr_active--;
+ }
+ /* The timer stops itself when no events are running. */
+ raw_spin_unlock_irqrestore(&axi->lock, irqflags);
+}
+
+static void bcm5301x_axi_read(struct perf_event *event)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(event->pmu);
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&axi->lock, flags);
+ if (!(event->hw.state & PERF_HES_STOPPED))
+ bcm5301x_axi_update(axi, event);
+ raw_spin_unlock_irqrestore(&axi->lock, flags);
+}
+
+static int bcm5301x_axi_add(struct perf_event *event, int flags)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(event->pmu);
+ unsigned int idx = event->attr.config;
+ unsigned long irqflags;
+
+ raw_spin_lock_irqsave(&axi->lock, irqflags);
+ if (axi->events[idx]) {
+ raw_spin_unlock_irqrestore(&axi->lock, irqflags);
+ return -EAGAIN;
+ }
+ axi->events[idx] = event;
+ event->hw.idx = idx;
+ event->hw.state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ raw_spin_unlock_irqrestore(&axi->lock, irqflags);
+
+ if (flags & PERF_EF_START)
+ bcm5301x_axi_start(event, PERF_EF_RELOAD);
+ perf_event_update_userpage(event);
+ return 0;
+}
+
+static void bcm5301x_axi_del(struct perf_event *event, int flags)
+{
+ struct bcm5301x_axi_pmu *axi = to_axi_pmu(event->pmu);
+ unsigned long irqflags;
+
+ bcm5301x_axi_stop(event, PERF_EF_UPDATE);
+ raw_spin_lock_irqsave(&axi->lock, irqflags);
+ axi->events[event->hw.idx] = NULL;
+ event->hw.idx = -1;
+ raw_spin_unlock_irqrestore(&axi->lock, irqflags);
+ perf_event_update_userpage(event);
+}
+
+static int bcm5301x_axi_offline(unsigned int cpu, struct hlist_node *node)
+{
+ struct bcm5301x_axi_pmu *axi = hlist_entry(node, typeof(*axi), hp_node);
+ unsigned int target;
+
+ if (cpu != READ_ONCE(axi->cpu))
+ return 0;
+ target = cpumask_any_but(cpu_online_mask, cpu);
+ if (target >= nr_cpu_ids)
+ return 0;
+ perf_pmu_migrate_context(&axi->pmu, cpu, target);
+ WRITE_ONCE(axi->cpu, target);
+ return 0;
+}
+
+static void bcm5301x_axi_hw_stop(struct bcm5301x_axi_pmu *axi)
+{
+ writel(ATM_STOP, axi->base + ATM_CMD);
+ /* Flush the posted command before the resource is unmapped. */
+ readl(axi->base + ATM_STATUS);
+}
+
+static int bcm5301x_axi_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct bcm5301x_axi_pmu *axi;
+ struct resource *res;
+ char *name;
+ u32 status;
+ int ret;
+
+ axi = devm_kzalloc(dev, sizeof(*axi), GFP_KERNEL);
+ if (!axi)
+ return -ENOMEM;
+ axi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(axi->base))
+ return PTR_ERR(axi->base);
+ if (resource_size(res) < SZ_4K)
+ return -EINVAL;
+ name = devm_kasprintf(dev, GFP_KERNEL, "bcm5301x_axi_%llx",
+ (unsigned long long)res->start);
+ if (!name)
+ return -ENOMEM;
+
+ raw_spin_lock_init(&axi->lock);
+ hrtimer_setup(&axi->timer, bcm5301x_axi_timer, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL);
+ axi->pmu = (struct pmu) {
+ .module = THIS_MODULE,
+ .parent = dev,
+ .task_ctx_nr = perf_invalid_context,
+ .capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
+ .attr_groups = bcm5301x_axi_attr_groups,
+ .event_init = bcm5301x_axi_event_init,
+ .add = bcm5301x_axi_add,
+ .del = bcm5301x_axi_del,
+ .start = bcm5301x_axi_start,
+ .stop = bcm5301x_axi_stop,
+ .read = bcm5301x_axi_read,
+ };
+
+ /* Take exclusive local ownership; disable tracing, filtering and saturation. */
+ writel(ATM_CTRL_LOCAL, axi->base + ATM_CONFIG);
+ writel(ATM_STOP, axi->base + ATM_CMD);
+ ret = readl_poll_timeout(axi->base + ATM_STATUS, status,
+ !(status & ATM_STATE_MASK), 1, 1000);
+ if (ret)
+ return dev_err_probe(dev, ret, "Counters did not stop\n");
+ writel(ATM_CLEAR, axi->base + ATM_CMD);
+ writel(ATM_CTRL_LOCAL | ATM_COUNT_ENABLE, axi->base + ATM_CONFIG);
+ writel(ATM_START, axi->base + ATM_CMD);
+ ret = readl_poll_timeout(axi->base + ATM_STATUS, status,
+ (status & ATM_STATE_MASK) == ATM_STATE_ENABLE, 1, 1000);
+ if (ret) {
+ bcm5301x_axi_hw_stop(axi);
+ return dev_err_probe(dev, ret, "Counters did not start\n");
+ }
+ /*
+ * Keep fixed counters free-running. Per-event baselines isolate sessions
+ * without clearing or stopping counters used by another perf event.
+ */
+ cpus_read_lock();
+ axi->cpu = cpumask_first(cpu_online_mask);
+ ret = perf_pmu_register(&axi->pmu, name, -1);
+ if (!ret) {
+ ret = cpuhp_state_add_instance_nocalls_cpuslocked(bcm5301x_axi_hp_state,
+ &axi->hp_node);
+ if (ret)
+ perf_pmu_unregister(&axi->pmu);
+ }
+ cpus_read_unlock();
+ if (ret) {
+ hrtimer_cancel(&axi->timer);
+ bcm5301x_axi_hw_stop(axi);
+ return ret;
+ }
+ platform_set_drvdata(pdev, axi);
+ return 0;
+}
+
+static void bcm5301x_axi_remove(struct platform_device *pdev)
+{
+ struct bcm5301x_axi_pmu *axi = platform_get_drvdata(pdev);
+
+ cpuhp_state_remove_instance_nocalls(bcm5301x_axi_hp_state, &axi->hp_node);
+ perf_pmu_unregister(&axi->pmu);
+ hrtimer_cancel(&axi->timer);
+ bcm5301x_axi_hw_stop(axi);
+}
+
+static const struct of_device_id bcm5301x_axi_of_match[] = {
+ { .compatible = "brcm,bcm5301x-axi-pmu" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, bcm5301x_axi_of_match);
+
+static struct platform_driver bcm5301x_axi_driver = {
+ .probe = bcm5301x_axi_probe,
+ .remove = bcm5301x_axi_remove,
+ .driver = {
+ .name = "bcm5301x-axi-pmu",
+ .of_match_table = bcm5301x_axi_of_match,
+ .suppress_bind_attrs = true,
+ },
+};
+
+static int __init bcm5301x_axi_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "perf/bcm5301x_axi:online",
+ NULL, bcm5301x_axi_offline);
+ if (ret < 0)
+ return ret;
+ bcm5301x_axi_hp_state = ret;
+ ret = platform_driver_register(&bcm5301x_axi_driver);
+ if (ret)
+ cpuhp_remove_multi_state(bcm5301x_axi_hp_state);
+ return ret;
+}
+module_init(bcm5301x_axi_init);
+
+static void __exit bcm5301x_axi_exit(void)
+{
+ platform_driver_unregister(&bcm5301x_axi_driver);
+ cpuhp_remove_multi_state(bcm5301x_axi_hp_state);
+}
+module_exit(bcm5301x_axi_exit);
+
+MODULE_DESCRIPTION("Broadcom BCM5301X AXI Trace Module PMU");
+MODULE_LICENSE("GPL");
--
2.53.0
^ permalink raw reply [flat|nested] 4+ messages in thread