Re: [PATCH v5 2/4] perf: add arm64 smmuv3 pmu driver
From: Robin Murphy
Date: Fri Jan 25 2019 - 10:14:00 EST
On 30/11/2018 15:47, Shameer Kolothum wrote:
From: Neil Leeder <nleeder@xxxxxxxxxxxxxx>
Adds a new driver to support the SMMUv3 PMU and add it into the
perf events framework.
Each SMMU node may have multiple PMUs associated with it, each of
which may support different events.
SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page> where
<phys_addr_page> is the physical page address of the SMMU PMCG
wrapped to 4K boundary. For example, the PMCG at 0xff88840000 is
named smmuv3_pmcg_ff88840
Filtering by stream id is done by specifying filtering parameters
with the event. options are:
filter_enable - 0 = no filtering, 1 = filtering enabled
filter_span - 0 = exact match, 1 = pattern match
filter_stream_id - pattern to filter against
Example: perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,
filter_span=1,filter_stream_id=0x42/ -a netperf
Applies filter pattern 0x42 to transaction events, which means events
matching stream ids 0x42 & 0x43 are counted as only upper StreamID
bits are required to match the given filter. Further filtering
information is available in the SMMU documentation.
SMMU events are not attributable to a CPU, so task mode and sampling
are not supported.
Signed-off-by: Neil Leeder <nleeder@xxxxxxxxxxxxxx>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/perf/Kconfig | 9 +
drivers/perf/Makefile | 1 +
drivers/perf/arm_smmuv3_pmu.c | 778 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 788 insertions(+)
create mode 100644 drivers/perf/arm_smmuv3_pmu.c
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 08ebaf7..92be6a3 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -52,6 +52,15 @@ config ARM_PMU_ACPI
depends on ARM_PMU && ACPI
def_bool y
+config ARM_SMMU_V3_PMU
+ bool "ARM SMMUv3 Performance Monitors Extension"
+ depends on ARM64 && ACPI && ARM_SMMU_V3
+ help
+ Provides support for the SMMU version 3 performance monitor unit (PMU)
+ on ARM-based systems.
+ Adds the SMMU PMU into the perf events subsystem for
+ monitoring SMMU performance events.
+
config ARM_DSU_PMU
tristate "ARM DynamIQ Shared Unit (DSU) PMU"
depends on ARM64
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index b3902bd..f10a932 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_ARM_CCN) += arm-ccn.o
obj-$(CONFIG_ARM_DSU_PMU) += arm_dsu_pmu.o
obj-$(CONFIG_ARM_PMU) += arm_pmu.o arm_pmu_platform.o
obj-$(CONFIG_ARM_PMU_ACPI) += arm_pmu_acpi.o
+obj-$(CONFIG_ARM_SMMU_V3_PMU) += arm_smmuv3_pmu.o
obj-$(CONFIG_HISI_PMU) += hisilicon/
obj-$(CONFIG_QCOM_L2_PMU) += qcom_l2_pmu.o
obj-$(CONFIG_QCOM_L3_PMU) += qcom_l3_pmu.o
diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
new file mode 100644
index 0000000..fb9dcd8
--- /dev/null
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -0,0 +1,778 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * This driver adds support for perf events to use the Performance
+ * Monitor Counter Groups (PMCG) associated with an SMMUv3 node
+ * to monitor that node.
+ *
+ * SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page> where
+ * <phys_addr_page> is the physical page address of the SMMU PMCG wrapped
+ * to 4K boundary. For example, the PMCG at 0xff88840000 is named
+ * smmuv3_pmcg_ff88840
+ *
+ * Filtering by stream id is done by specifying filtering parameters
+ * with the event. options are:
+ * filter_enable - 0 = no filtering, 1 = filtering enabled
+ * filter_span - 0 = exact match, 1 = pattern match
+ * filter_stream_id - pattern to filter against
+ *
+ * To match a partial StreamID where the X most-significant bits must match
+ * but the Y least-significant bits might differ, STREAMID is programmed
+ * with a value that contains:
+ * STREAMID[Y - 1] == 0.
+ * STREAMID[Y - 2:0] == 1 (where Y > 1).
+ * The remainder of implemented bits of STREAMID (X bits, from bit Y upwards)
+ * contain a value to match from the corresponding bits of event StreamID.
+ *
+ * Example: perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,
+ * filter_span=1,filter_stream_id=0x42/ -a netperf
+ * Applies filter pattern 0x42 to transaction events, which means events
+ * matching stream ids 0x42 and 0x43 are counted. Further filtering
+ * information is available in the SMMU documentation.
+ *
+ * SMMU events are not attributable to a CPU, so task mode and sampling
+ * are not supported.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cpuhotplug.h>
+#include <linux/cpumask.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/msi.h>
+#include <linux/perf_event.h>
+#include <linux/platform_device.h>
+#include <linux/smp.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#define SMMU_PMCG_EVCNTR0 0x0
+#define SMMU_PMCG_EVCNTR(n, stride) (SMMU_PMCG_EVCNTR0 + (n) * (stride))
+#define SMMU_PMCG_EVTYPER0 0x400
+#define SMMU_PMCG_EVTYPER(n) (SMMU_PMCG_EVTYPER0 + (n) * 4)
+#define SMMU_PMCG_SID_SPAN_SHIFT 29
+#define SMMU_PMCG_SID_SPAN_MASK GENMASK(29, 29)
Surely just:
#define SMMU_PMCG_SID_SPAN BIT(29)
(or maybe even SMMU_PMCG_EVTYPER_SID_SPAN for clarity)?
+#define SMMU_PMCG_SMR0 0xA00
+#define SMMU_PMCG_SMR(n) (SMMU_PMCG_SMR0 + (n) * 4)
+#define SMMU_PMCG_CNTENSET0 0xC00
+#define SMMU_PMCG_CNTENCLR0 0xC20
+#define SMMU_PMCG_INTENSET0 0xC40
+#define SMMU_PMCG_INTENCLR0 0xC60
+#define SMMU_PMCG_OVSCLR0 0xC80
+#define SMMU_PMCG_OVSSET0 0xCC0
+#define SMMU_PMCG_CFGR 0xE00
+#define SMMU_PMCG_CFGR_RELOC_CTRS BIT(20)
+#define SMMU_PMCG_CFGR_SID_FILTER_TYPE BIT(23)
+#define SMMU_PMCG_CFGR_SIZE_MASK GENMASK(13, 8)
+#define SMMU_PMCG_CFGR_NCTR_MASK GENMASK(5, 0)
Nit: as long as we use the bitfield accessors consistently, these _MASK
suffixes are a bit of a waste of space IMO.
+#define SMMU_PMCG_CR 0xE04
+#define SMMU_PMCG_CR_ENABLE BIT(0)
+#define SMMU_PMCG_CEID0 0xE20
+#define SMMU_PMCG_CEID1 0xE28
+#define SMMU_PMCG_IRQ_CTRL 0xE50
+#define SMMU_PMCG_IRQ_CTRL_IRQEN BIT(0)
+#define SMMU_PMCG_IRQ_CFG0 0xE58
+
+#define SMMU_DEFAULT_FILTER_SPAN 1
+#define SMMU_DEFAULT_FILTER_STREAM_ID GENMASK(31, 0)
+
+#define SMMU_MAX_COUNTERS 64
+#define SMMU_ARCH_MAX_EVENT_ID 0x7F
+#define SMMU_IMPDEF_MAX_EVENT_ID 0xFFFF
+#define SMMU_ARCH_MAX_EVENTS (SMMU_ARCH_MAX_EVENT_ID + 1)
Do we really need two definitions of effectively the same thing?
+
+#define SMMU_PA_SHIFT 12
+
+static int cpuhp_state_num;
+
+struct smmu_pmu {
+ bool sid_filter_global;
+ struct hlist_node node;
+ struct perf_event *events[SMMU_MAX_COUNTERS];
+ DECLARE_BITMAP(used_counters, SMMU_MAX_COUNTERS);
+ DECLARE_BITMAP(supported_events, SMMU_ARCH_MAX_EVENTS);
+ unsigned int irq;
+ unsigned int on_cpu;
+ struct pmu pmu;
+ unsigned int num_counters;
+ struct device *dev;
+ void __iomem *reg_base;
+ void __iomem *reloc_base;
+ u64 counter_present_mask;
+ u64 counter_mask;
+};
+
+#define to_smmu_pmu(p) (container_of(p, struct smmu_pmu, pmu))
+
+#define SMMU_PMU_EVENT_ATTR_EXTRACTOR(_name, _config, _start, _end) \
+ static inline u32 get_##_name(struct perf_event *event) \
+ { \
+ return FIELD_GET(GENMASK_ULL(_end, _start), \
+ event->attr._config); \
+ } \
+
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(event, config, 0, 15);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_stream_id, config1, 0, 31);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_span, config1, 32, 32);
+SMMU_PMU_EVENT_ATTR_EXTRACTOR(filter_enable, config1, 33, 33);
+
+static inline void smmu_pmu_enable(struct pmu *pmu)
+{
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+
+ writel(SMMU_PMCG_CR_ENABLE, smmu_pmu->reg_base + SMMU_PMCG_CR);
+ writel(SMMU_PMCG_IRQ_CTRL_IRQEN,
+ smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
+}
+
+static inline void smmu_pmu_disable(struct pmu *pmu)
+{
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(pmu);
+
+ writel(0, smmu_pmu->reg_base + SMMU_PMCG_CR);
+ writel(0, smmu_pmu->reg_base + SMMU_PMCG_IRQ_CTRL);
+}
+
+static inline void smmu_pmu_counter_set_value(struct smmu_pmu *smmu_pmu,
+ u32 idx, u64 value)
+{
+ if (smmu_pmu->counter_mask & BIT(32))
+ writeq(value, smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 8));
+ else
+ writel(value, smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 4));
+}
+
+static inline u64 smmu_pmu_counter_get_value(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+ u64 value;
+
+ if (smmu_pmu->counter_mask & BIT(32))
+ value = readq(smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 8));
+ else
+ value = readl(smmu_pmu->reloc_base + SMMU_PMCG_EVCNTR(idx, 4));
+
+ return value;
+}
+
+static inline void smmu_pmu_counter_enable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+ writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_CNTENSET0);
+}
+
+static inline void smmu_pmu_counter_disable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+ writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
+}
+
+static inline void smmu_pmu_interrupt_enable(struct smmu_pmu *smmu_pmu, u32 idx)
+{
+ writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_INTENSET0);
+}
+
+static inline void smmu_pmu_interrupt_disable(struct smmu_pmu *smmu_pmu,
+ u32 idx)
+{
+ writeq(BIT(idx), smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);
+}
+
+static inline void smmu_pmu_set_evtyper(struct smmu_pmu *smmu_pmu, u32 idx,
+ u32 val)
+{
+ writel(val, smmu_pmu->reg_base + SMMU_PMCG_EVTYPER(idx));
+}
+
+static inline void smmu_pmu_set_smr(struct smmu_pmu *smmu_pmu, u32 idx, u32 val)
+{
+ writel(val, smmu_pmu->reg_base + SMMU_PMCG_SMR(idx));
+}
+
+static void smmu_pmu_event_update(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+ u64 delta, prev, now;
+ u32 idx = hwc->idx;
+
+ do {
+ prev = local64_read(&hwc->prev_count);
+ now = smmu_pmu_counter_get_value(smmu_pmu, idx);
+ } while (local64_cmpxchg(&hwc->prev_count, prev, now) != prev);
+
+ /* handle overflow. */
+ delta = now - prev;
+ delta &= smmu_pmu->counter_mask;
+
+ local64_add(delta, &event->count);
+}
+
+static void smmu_pmu_set_period(struct smmu_pmu *smmu_pmu,
+ struct hw_perf_event *hwc)
+{
+ u32 idx = hwc->idx;
+ u64 new;
+
+ /*
+ * We limit the max period to half the max counter value of the counter
+ * size, so that even in the case of extreme interrupt latency the
+ * counter will (hopefully) not wrap past its initial value.
+ */
+ new = smmu_pmu->counter_mask >> 1;
+
+ local64_set(&hwc->prev_count, new);
+ smmu_pmu_counter_set_value(smmu_pmu, idx, new);
+}
+
+static void smmu_pmu_get_event_filter(struct perf_event *event, u32 *span,
+ u32 *stream_id)
It might just be me, but those u32s seem a little non-obvious given that
they're both actually communicating boolean values.
+{
+ bool filter_en = !!get_filter_enable(event);
+
+ *span = filter_en ? get_filter_span(event) : SMMU_DEFAULT_FILTER_SPAN;
+ *stream_id = filter_en ? get_filter_stream_id(event) :
+ SMMU_DEFAULT_FILTER_STREAM_ID;
+}
+
+static bool smmu_pmu_event_filter_valid(struct smmu_pmu *smmu_pmu,
+ struct perf_event *event, int idx)
+{
+ u32 filter_span, filter_sid;
+ u32 curr_span, curr_sid;
+
+ if (!idx || !smmu_pmu->sid_filter_global)
+ return true;
Consider this sequence on an initially-empty PMCG with global filtering:
- add event A with filter X
- add event B with filter X
- delete event A
- add event C with filter Y
event B is suddenly filtered by Y. Oops.
+ smmu_pmu_get_event_filter(event, &filter_span, &filter_sid);
+
+ /* Read the current global filter setting */
+ curr_span = FIELD_GET(SMMU_PMCG_SID_SPAN_MASK,
+ readl(smmu_pmu->reg_base + SMMU_PMCG_EVTYPER0));
+ curr_sid = readl(smmu_pmu->reg_base + SMMU_PMCG_SMR0);
The solution to the above problem will likely help avoid this slightly
yucky reading back of register state, too.
+
+ if (filter_span != curr_span || filter_sid != curr_sid)
+ return false;
+
+ return true;
+}
+
+static int smmu_pmu_get_event_idx(struct smmu_pmu *smmu_pmu,
+ struct perf_event *event)
+{
+ unsigned int idx;
+ unsigned int num_ctrs = smmu_pmu->num_counters;
+
+ idx = find_first_zero_bit(smmu_pmu->used_counters, num_ctrs);
+ if (idx == num_ctrs)
+ /* The counters are all in use. */
+ return -EAGAIN;
+
+ if (!smmu_pmu_event_filter_valid(smmu_pmu, event, idx))
+ return -EAGAIN;
+
+ set_bit(idx, smmu_pmu->used_counters);
+
+ return idx;
+}
+
+/*
+ * Implementation of abstract pmu functionality required by
+ * the core perf events code.
+ */
+
+static int smmu_pmu_event_init(struct perf_event *event)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+ struct device *dev = smmu_pmu->dev;
+ struct perf_event *sibling;
+ u32 event_id;
+
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+
+ if (hwc->sample_period) {
+ dev_dbg(dev, "Sampling not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (event->cpu < 0) {
+ dev_dbg(dev, "Per-task mode not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* We cannot filter accurately so we just don't allow it. */
+ if (event->attr.exclude_user || event->attr.exclude_kernel ||
+ event->attr.exclude_hv || event->attr.exclude_idle) {
+ dev_dbg(dev, "Can't exclude execution levels\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* Verify specified event is supported on this PMU */
+ event_id = get_event(event);
Given what this does...
+ if (((event_id <= SMMU_ARCH_MAX_EVENT_ID) &&
+ (!test_bit(event_id, smmu_pmu->supported_events))) ||
+ (event_id > SMMU_IMPDEF_MAX_EVENT_ID)) {
...how can this last condition ever be true? On which note, event_id
could also be a u16 here, which might aid clarity even more.
Really, both MAX_EVENT_ID definitions seem redundant.
+ dev_dbg(dev, "Invalid event %d for this PMU\n", event_id);
+ return -EINVAL;
+ }
+
+ /* Don't allow groups with mixed PMUs, except for s/w events */
+ if (event->group_leader->pmu != event->pmu &&
+ !is_software_event(event->group_leader)) {
+ dev_dbg(dev, "Can't create mixed PMU group\n");
+ return -EINVAL;
+ }
+
+ list_for_each_entry(sibling, &event->group_leader->sibling_list,
+ sibling_list)
Maybe consider the for_each_sibling_event() helper?
+ if (sibling->pmu != event->pmu &&
+ !is_software_event(sibling)) {
+ dev_dbg(dev, "Can't create mixed PMU group\n");
+ return -EINVAL;
+ }
+
+ /* Ensure all events in a group are on the same cpu */
+ if ((event->group_leader != event) &&
+ (event->cpu != event->group_leader->cpu)) {
+ dev_dbg(dev, "Can't create group on CPUs %d and %d\n",
+ event->cpu, event->group_leader->cpu);
+ return -EINVAL;
+ }
Is this really necessary? At this point, event->cpu might not have the
value that we're just about to force it to, and AFAICS perf_event_open()
will eventually bail out if they don't end up matching anyway.
+
+ hwc->idx = -1;
+
+ /*
+ * Ensure all events are on the same cpu so all events are in the
+ * same cpu context, to avoid races on pmu_enable etc.
+ */
+ event->cpu = smmu_pmu->on_cpu;
+
+ return 0;
+}
+
+static void smmu_pmu_event_start(struct perf_event *event, int flags)
+{
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+ u32 filter_span, filter_sid;
+ u32 evtyper;
+
+ hwc->state = 0;
+
+ smmu_pmu_set_period(smmu_pmu, hwc);
+
+ smmu_pmu_get_event_filter(event, &filter_span, &filter_sid);
+
+ evtyper = get_event(event) |
+ filter_span << SMMU_PMCG_SID_SPAN_SHIFT;
+
+ smmu_pmu_set_evtyper(smmu_pmu, idx, evtyper);
+ smmu_pmu_set_smr(smmu_pmu, idx, filter_sid);
Careful, SMRn and EVTYPERn.FILTER_SID_SPAN are RES0 for n > 0 with
global filtering, so we shouldn't *always* be writing to them.
+ smmu_pmu_interrupt_enable(smmu_pmu, idx);
+ smmu_pmu_counter_enable(smmu_pmu, idx);
+}
+
+static void smmu_pmu_event_stop(struct perf_event *event, int flags)
+{
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int idx = hwc->idx;
+
+ if (hwc->state & PERF_HES_STOPPED)
+ return;
+
+ smmu_pmu_counter_disable(smmu_pmu, idx);
+
+ if (flags & PERF_EF_UPDATE)
+ smmu_pmu_event_update(event);
+ hwc->state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
+}
+
+static int smmu_pmu_event_add(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ int idx;
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+
+ idx = smmu_pmu_get_event_idx(smmu_pmu, event);
+ if (idx < 0)
+ return idx;
+
+ hwc->idx = idx;
+ hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
+ smmu_pmu->events[idx] = event;
+ local64_set(&hwc->prev_count, 0);
+
+ if (flags & PERF_EF_START)
+ smmu_pmu_event_start(event, flags);
+
+ /* Propagate changes to the userspace mapping. */
+ perf_event_update_userpage(event);
+
+ return 0;
+}
+
+static void smmu_pmu_event_del(struct perf_event *event, int flags)
+{
+ struct hw_perf_event *hwc = &event->hw;
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(event->pmu);
+ int idx = hwc->idx;
+
+ smmu_pmu_event_stop(event, flags | PERF_EF_UPDATE);
+ smmu_pmu->events[idx] = NULL;
+ clear_bit(idx, smmu_pmu->used_counters);
+
+ perf_event_update_userpage(event);
+}
+
+static void smmu_pmu_event_read(struct perf_event *event)
+{
+ smmu_pmu_event_update(event);
+}
+
+/* cpumask */
+
+static ssize_t smmu_pmu_cpumask_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(dev_get_drvdata(dev));
+
+ return cpumap_print_to_pagebuf(true, buf, cpumask_of(smmu_pmu->on_cpu));
+}
+
+static struct device_attribute smmu_pmu_cpumask_attr =
+ __ATTR(cpumask, 0444, smmu_pmu_cpumask_show, NULL);
+
+static struct attribute *smmu_pmu_cpumask_attrs[] = {
+ &smmu_pmu_cpumask_attr.attr,
+ NULL
+};
+
+static struct attribute_group smmu_pmu_cpumask_group = {
+ .attrs = smmu_pmu_cpumask_attrs,
+};
+
+/* Events */
+
+ssize_t smmu_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 sprintf(page, "event=0x%02llx\n", pmu_attr->id);
+}
+
+#define SMMU_EVENT_ATTR(_name, _id) \
+ (&((struct perf_pmu_events_attr[]) { \
+ { .attr = __ATTR(_name, 0444, smmu_pmu_event_show, NULL), \
+ .id = _id, } \
+ })[0].attr.attr)
+
+static struct attribute *smmu_pmu_events[] = {
+ SMMU_EVENT_ATTR(cycles, 0),
+ SMMU_EVENT_ATTR(transaction, 1),
+ SMMU_EVENT_ATTR(tlb_miss, 2),
+ SMMU_EVENT_ATTR(config_cache_miss, 3),
+ SMMU_EVENT_ATTR(trans_table_walk_access, 4),
+ SMMU_EVENT_ATTR(config_struct_access, 5),
+ SMMU_EVENT_ATTR(pcie_ats_trans_rq, 6),
+ SMMU_EVENT_ATTR(pcie_ats_trans_passed, 7),
+ NULL
+};
+
+static umode_t smmu_pmu_event_is_visible(struct kobject *kobj,
+ struct attribute *attr, int unused)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct smmu_pmu *smmu_pmu = to_smmu_pmu(dev_get_drvdata(dev));
+ struct perf_pmu_events_attr *pmu_attr;
+
+ pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
+
+ if (test_bit(pmu_attr->id, smmu_pmu->supported_events))
+ return attr->mode;
+
+ return 0;
+}
+static struct attribute_group smmu_pmu_events_group = {
+ .name = "events",
+ .attrs = smmu_pmu_events,
+ .is_visible = smmu_pmu_event_is_visible,
+};
+
+/* Formats */
+PMU_FORMAT_ATTR(event, "config:0-15");
+PMU_FORMAT_ATTR(filter_stream_id, "config1:0-31");
+PMU_FORMAT_ATTR(filter_span, "config1:32");
+PMU_FORMAT_ATTR(filter_enable, "config1:33");
+
+static struct attribute *smmu_pmu_formats[] = {
+ &format_attr_event.attr,
+ &format_attr_filter_stream_id.attr,
+ &format_attr_filter_span.attr,
+ &format_attr_filter_enable.attr,
+ NULL
+};
+
+static struct attribute_group smmu_pmu_format_group = {
+ .name = "format",
+ .attrs = smmu_pmu_formats,
+};
+
+static const struct attribute_group *smmu_pmu_attr_grps[] = {
+ &smmu_pmu_cpumask_group,
+ &smmu_pmu_events_group,
+ &smmu_pmu_format_group,
+ NULL
+};
+
+/*
+ * Generic device handlers
+ */
+
+static int smmu_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct smmu_pmu *smmu_pmu;
+ unsigned int target;
+
+ smmu_pmu = hlist_entry_safe(node, struct smmu_pmu, node);
+ if (cpu != smmu_pmu->on_cpu)
+ return 0;
+
+ target = cpumask_any_but(cpu_online_mask, cpu);
+ if (target >= nr_cpu_ids)
+ return 0;
+
+ perf_pmu_migrate_context(&smmu_pmu->pmu, cpu, target);
+ smmu_pmu->on_cpu = target;
+ WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(target)));
+
+ return 0;
+}
+
+static irqreturn_t smmu_pmu_handle_irq(int irq_num, void *data)
+{
+ struct smmu_pmu *smmu_pmu = data;
+ u64 ovsr;
+ unsigned int idx;
+
+ ovsr = readq(smmu_pmu->reloc_base + SMMU_PMCG_OVSSET0);
+ if (!ovsr)
+ return IRQ_NONE;
+
+ writeq(ovsr, smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
+
+ for_each_set_bit(idx, (unsigned long *)&ovsr, smmu_pmu->num_counters) {
+ struct perf_event *event = smmu_pmu->events[idx];
+ struct hw_perf_event *hwc;
+
+ if (WARN_ON_ONCE(!event))
+ continue;
+
+ smmu_pmu_event_update(event);
+ hwc = &event->hw;
+
+ smmu_pmu_set_period(smmu_pmu, hwc);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int smmu_pmu_setup_irq(struct smmu_pmu *pmu)
+{
+ unsigned long flags = IRQF_NOBALANCING | IRQF_SHARED | IRQF_NO_THREAD;
+ int irq, ret = -ENXIO;
+
+ irq = pmu->irq;
+ if (irq)
+ ret = devm_request_irq(pmu->dev, irq, smmu_pmu_handle_irq,
+ flags, "smmuv3-pmu", pmu);
+ return ret;
+}
+
+static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu)
+{
+ smmu_pmu_disable(&smmu_pmu->pmu);
+
+ /* Disable counter and interrupt */
+ writeq_relaxed(smmu_pmu->counter_present_mask,
+ smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
+ writeq_relaxed(smmu_pmu->counter_present_mask,
+ smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);
I suppose if we really wanted to save on register-poking in
event_add/event_del, we *could* permanently enable the per-counter
interrupts here and just rely on enable/disable/event_start/event_stop
naturally preventing anything unexpected. That's a little non-obvious,
though, so unless there proves to be some concrete benefit I'm inclined
to stick with the logically-straightforward approach suggested yesterday.
+ writeq_relaxed(smmu_pmu->counter_present_mask,
+ smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);
+}
+
+static int smmu_pmu_probe(struct platform_device *pdev)
+{
+ struct smmu_pmu *smmu_pmu;
+ struct resource *res_0, *res_1;
+ u32 cfgr, reg_size;
+ u64 ceid_64[2];
+ int irq, err;
+ char *name;
+ struct device *dev = &pdev->dev;
+
+ smmu_pmu = devm_kzalloc(dev, sizeof(*smmu_pmu), GFP_KERNEL);
+ if (!smmu_pmu)
+ return -ENOMEM;
+
+ smmu_pmu->dev = dev;
+ platform_set_drvdata(pdev, smmu_pmu);
+
+ smmu_pmu->pmu = (struct pmu) {
+ .task_ctx_nr = perf_invalid_context,
+ .pmu_enable = smmu_pmu_enable,
+ .pmu_disable = smmu_pmu_disable,
+ .event_init = smmu_pmu_event_init,
+ .add = smmu_pmu_event_add,
+ .del = smmu_pmu_event_del,
+ .start = smmu_pmu_event_start,
+ .stop = smmu_pmu_event_stop,
+ .read = smmu_pmu_event_read,
+ .attr_groups = smmu_pmu_attr_grps,
+ };
+
+ res_0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ smmu_pmu->reg_base = devm_ioremap_resource(dev, res_0);
+ if (IS_ERR(smmu_pmu->reg_base))
+ return PTR_ERR(smmu_pmu->reg_base);
+
+ cfgr = readl_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CFGR);
+
+ /* Determine if page 1 is present */
+ if (cfgr & SMMU_PMCG_CFGR_RELOC_CTRS) {
+ res_1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ smmu_pmu->reloc_base = devm_ioremap_resource(dev, res_1);
+ if (IS_ERR(smmu_pmu->reloc_base))
+ return PTR_ERR(smmu_pmu->reloc_base);
+ } else {
+ smmu_pmu->reloc_base = smmu_pmu->reg_base;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq > 0)
+ smmu_pmu->irq = irq;
+
+ ceid_64[0] = readq_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CEID0);
+ ceid_64[1] = readq_relaxed(smmu_pmu->reg_base + SMMU_PMCG_CEID1);
+ bitmap_from_arr32(smmu_pmu->supported_events, (u32 *)ceid_64,
+ SMMU_ARCH_MAX_EVENTS);
+
+ smmu_pmu->num_counters = FIELD_GET(SMMU_PMCG_CFGR_NCTR_MASK, cfgr) + 1;
+ smmu_pmu->counter_present_mask = GENMASK(smmu_pmu->num_counters - 1, 0);
GENMASK_ULL() for consistency?
Although it looks like we now only ever use counter_present_mask in the
reset routine anyway, so maybe we could just dynamically generate it
there instead of storing it.
Robin.
+
+ smmu_pmu->sid_filter_global = !!(cfgr & SMMU_PMCG_CFGR_SID_FILTER_TYPE);
+
+ reg_size = FIELD_GET(SMMU_PMCG_CFGR_SIZE_MASK, cfgr);
+ smmu_pmu->counter_mask = GENMASK_ULL(reg_size, 0);
+
+ smmu_pmu_reset(smmu_pmu);
+
+ err = smmu_pmu_setup_irq(smmu_pmu);
+ if (err) {
+ dev_err(dev, "Setup irq failed, PMU @%pa\n", &res_0->start);
+ return err;
+ }
+
+ name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "smmuv3_pmcg_%llx",
+ (res_0->start) >> SMMU_PA_SHIFT);
+ if (!name) {
+ dev_err(dev, "Create name failed, PMU @%pa\n", &res_0->start);
+ return -EINVAL;
+ }
+
+ /* Pick one CPU to be the preferred one to use */
+ smmu_pmu->on_cpu = get_cpu();
+ WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu)));
+
+ err = cpuhp_state_add_instance_nocalls(cpuhp_state_num,
+ &smmu_pmu->node);
+ if (err) {
+ dev_err(dev, "Error %d registering hotplug, PMU @%pa\n",
+ err, &res_0->start);
+ goto out_cpuhp_err;
+ }
+
+ err = perf_pmu_register(&smmu_pmu->pmu, name, -1);
+ if (err) {
+ dev_err(dev, "Error %d registering PMU @%pa\n",
+ err, &res_0->start);
+ goto out_unregister;
+ }
+
+ put_cpu();
+ dev_info(dev, "Registered PMU @ %pa using %d counters with %s filter settings\n",
+ &res_0->start, smmu_pmu->num_counters,
+ smmu_pmu->sid_filter_global ? "Global(Counter0)" :
+ "Individual");
+
+ return 0;
+
+out_unregister:
+ cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node);
+out_cpuhp_err:
+ put_cpu();
+ return err;
+}
+
+static int smmu_pmu_remove(struct platform_device *pdev)
+{
+ struct smmu_pmu *smmu_pmu = platform_get_drvdata(pdev);
+
+ perf_pmu_unregister(&smmu_pmu->pmu);
+ cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &smmu_pmu->node);
+
+ return 0;
+}
+
+static void smmu_pmu_shutdown(struct platform_device *pdev)
+{
+ struct smmu_pmu *smmu_pmu = platform_get_drvdata(pdev);
+
+ smmu_pmu_disable(&smmu_pmu->pmu);
+}
+
+static struct platform_driver smmu_pmu_driver = {
+ .driver = {
+ .name = "arm-smmu-v3-pmu",
+ },
+ .probe = smmu_pmu_probe,
+ .remove = smmu_pmu_remove,
+ .shutdown = smmu_pmu_shutdown,
+};
+
+static int __init arm_smmu_pmu_init(void)
+{
+ cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
+ "perf/arm/pmcg:online",
+ NULL,
+ smmu_pmu_offline_cpu);
+ if (cpuhp_state_num < 0)
+ return cpuhp_state_num;
+
+ return platform_driver_register(&smmu_pmu_driver);
+}
+module_init(arm_smmu_pmu_init);
+
+static void __exit arm_smmu_pmu_exit(void)
+{
+ platform_driver_unregister(&smmu_pmu_driver);
+ cpuhp_remove_multi_state(cpuhp_state_num);
+}
+
+module_exit(arm_smmu_pmu_exit);
+
+MODULE_DESCRIPTION("PMU driver for ARM SMMUv3 Performance Monitors Extension");
+MODULE_AUTHOR("Neil Leeder <nleeder@xxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");