This patch series adds DDR performance monitor support
on Marvell cn10k series of processor.
First patch adds device tree binding changes.
Second patch add basic support (without overflow and event
ownership). Third and fourth patch adds overflow and event
ownership respectively.
Seems like 4th patch can be merged in second patch,
For easy review it is currently separate
v5->v6:
- Changed COMPILE_TEST to (COMPILE_TEST && 64BIT)
v4->v5:
- Added missing COMPILE_TEST dependency
v3->v4:
- Added Rob Herring reviewed-by for dt-binding patch
v2->v3:
- dt-binding, ddrcpmu@1 -> pmu@87e1c0000000
- Add COMPILE_TEST as a dependency
- Switch to sysfs_emit()
- Error propagation when invalif event requested
- Switch to devm_platform_get_and_ioremap_resource()
- Other review comments on v2.
v1->v2:
- DT binding changed to new DT Schema
- writeq/readq changed to respective relaxed
- Using PMU_EVENT_ATTR_ID
Bharat Bhushan (4):
dt-bindings: perf: marvell: cn10k ddr performance monitor
perf/marvell: CN10k DDR performance monitor support
perf/marvell: cn10k DDR perfmon event overflow handling
perf/marvell: cn10k DDR perf event core ownership
.../bindings/perf/marvell-cn10k-ddr.yaml | 37 +
drivers/perf/Kconfig | 7 +
drivers/perf/Makefile | 1 +
drivers/perf/marvell_cn10k_ddr_pmu.c | 756 ++++++++++++++++++
include/linux/cpuhotplug.h | 1 +
5 files changed, 802 insertions(+)
create mode 100644 Documentation/devicetree/bindings/perf/marvell-cn10k-ddr.yaml
create mode 100644 drivers/perf/marvell_cn10k_ddr_pmu.c
--
2.17.1
Add binding documentation for the Marvell CN10k DDR
performance monitor unit.
Signed-off-by: Bharat Bhushan <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
v4->v6:
- No Change
v3->v4:
- Added Rob Herring reviewed-by
v2->v3:
- dt-binding, ddrcpmu@1 -> pmu@87e1c0000000
v1->v2:
- DT binding changed to new DT Schema
.../bindings/perf/marvell-cn10k-ddr.yaml | 37 +++++++++++++++++++
1 file changed, 37 insertions(+)
create mode 100644 Documentation/devicetree/bindings/perf/marvell-cn10k-ddr.yaml
diff --git a/Documentation/devicetree/bindings/perf/marvell-cn10k-ddr.yaml b/Documentation/devicetree/bindings/perf/marvell-cn10k-ddr.yaml
new file mode 100644
index 000000000000..a18dd0a8c43a
--- /dev/null
+++ b/Documentation/devicetree/bindings/perf/marvell-cn10k-ddr.yaml
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/perf/marvell-cn10k-ddr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Marvell CN10K DDR performance monitor
+
+maintainers:
+ - Bharat Bhushan <[email protected]>
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - marvell,cn10k-ddr-pmu
+
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ bus {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ pmu@87e1c0000000 {
+ compatible = "marvell,cn10k-ddr-pmu";
+ reg = <0x87e1 0xc0000000 0x0 0x10000>;
+ };
+ };
--
2.17.1
Marvell CN10k DRAM Subsystem (DSS) supports eight event counters for
monitoring performance and software can program each counter to monitor
any of the defined performance event. Performance events are for
interface between the DDR controller and the PHY, interface between the
DDR Controller and the CHI interconnect, or within the DDR Controller.
Additionally DSS also supports two fixed performance event counters, one
for number of ddr reads and other for ddr writes.
This patch add basic support for these performance monitoring events
on CN10k.
Signed-off-by: Bharat Bhushan <[email protected]>
---
v5->v6:
- Changed COMPILE_TEST to (COMPILE_TEST && 64BIT)
v4->v5:
- Added missing COMPILE_TEST dependency
v3->v4:
- No Change
v2->v3:
- Add COMPILE_TEST as a dependency
- Switch to sysfs_emit()
- Error propagation when invalif event requested
- Switch to devm_platform_get_and_ioremap_resource()
- Other review comments on v2.
v1->v2:
- writeq/readq changed to respective relaxed version
- Using PMU_EVENT_ATTR_ID
drivers/perf/Kconfig | 7 +
drivers/perf/Makefile | 1 +
drivers/perf/marvell_cn10k_ddr_pmu.c | 599 +++++++++++++++++++++++++++
3 files changed, 607 insertions(+)
create mode 100644 drivers/perf/marvell_cn10k_ddr_pmu.c
diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig
index 77522e5efe11..3fd6f9ebf586 100644
--- a/drivers/perf/Kconfig
+++ b/drivers/perf/Kconfig
@@ -139,4 +139,11 @@ config ARM_DMC620_PMU
source "drivers/perf/hisilicon/Kconfig"
+config MARVELL_CN10K_DDR_PMU
+ tristate "Enable MARVELL CN10K DRAM Subsystem(DSS) PMU Support"
+ depends on ARM64 || (COMPILE_TEST && 64BIT)
+ help
+ Enable perf support for Marvell DDR Performance monitoring
+ event on CN10K platform.
+
endmenu
diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile
index 5260b116c7da..ee1126219d8d 100644
--- a/drivers/perf/Makefile
+++ b/drivers/perf/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o
obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o
obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o
obj-$(CONFIG_ARM_DMC620_PMU) += arm_dmc620_pmu.o
+obj-$(CONFIG_MARVELL_CN10K_DDR_PMU) += marvell_cn10k_ddr_pmu.o
diff --git a/drivers/perf/marvell_cn10k_ddr_pmu.c b/drivers/perf/marvell_cn10k_ddr_pmu.c
new file mode 100644
index 000000000000..9b6d5e716b94
--- /dev/null
+++ b/drivers/perf/marvell_cn10k_ddr_pmu.c
@@ -0,0 +1,599 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Marvell CN10K DRAM Subsystem (DSS) Performance Monitor Driver
+ *
+ * Copyright (C) 2021 Marvell.
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/perf_event.h>
+
+/* Performance Counters Operating Mode Control Registers */
+#define DDRC_PERF_CNT_OP_MODE_CTRL 0x8020
+#define OP_MODE_CTRL_VAL_MANNUAL 0x1
+
+/* Performance Counters Start Operation Control Registers */
+#define DDRC_PERF_CNT_START_OP_CTRL 0x8028
+#define START_OP_CTRL_VAL_START 0x1ULL
+#define START_OP_CTRL_VAL_ACTIVE 0x2
+
+/* Performance Counters End Operation Control Registers */
+#define DDRC_PERF_CNT_END_OP_CTRL 0x8030
+#define END_OP_CTRL_VAL_END 0x1ULL
+
+/* Performance Counters End Status Registers */
+#define DDRC_PERF_CNT_END_STATUS 0x8038
+#define END_STATUS_VAL_END_TIMER_MODE_END 0x1
+
+/* Performance Counters Configuration Registers */
+#define DDRC_PERF_CFG_BASE 0x8040
+
+/* 8 Generic event counter + 2 fixed event counters */
+#define DDRC_PERF_NUM_GEN_COUNTERS 8
+#define DDRC_PERF_NUM_FIX_COUNTERS 2
+#define DDRC_PERF_READ_COUNTER_IDX DDRC_PERF_NUM_GEN_COUNTERS
+#define DDRC_PERF_WRITE_COUNTER_IDX (DDRC_PERF_NUM_GEN_COUNTERS + 1)
+#define DDRC_PERF_NUM_COUNTERS (DDRC_PERF_NUM_GEN_COUNTERS + \
+ DDRC_PERF_NUM_FIX_COUNTERS)
+
+/* Generic event counter registers */
+#define DDRC_PERF_CFG(n) (DDRC_PERF_CFG_BASE + 8 * (n))
+#define EVENT_ENABLE BIT_ULL(63)
+
+/* Two dedicated event counters for DDR reads and writes */
+#define EVENT_DDR_READS 101
+#define EVENT_DDR_WRITES 100
+
+/*
+ * programmable events IDs in programmable event counters.
+ * DO NOT change these event-id numbers, they are used to
+ * program event bitmap in h/w.
+ */
+#define EVENT_OP_IS_ZQLATCH 55
+#define EVENT_OP_IS_ZQSTART 54
+#define EVENT_OP_IS_TCR_MRR 53
+#define EVENT_OP_IS_DQSOSC_MRR 52
+#define EVENT_OP_IS_DQSOSC_MPC 51
+#define EVENT_VISIBLE_WIN_LIMIT_REACHED_WR 50
+#define EVENT_VISIBLE_WIN_LIMIT_REACHED_RD 49
+#define EVENT_BSM_STARVATION 48
+#define EVENT_BSM_ALLOC 47
+#define EVENT_LPR_REQ_WITH_NOCREDIT 46
+#define EVENT_HPR_REQ_WITH_NOCREDIT 45
+#define EVENT_OP_IS_ZQCS 44
+#define EVENT_OP_IS_ZQCL 43
+#define EVENT_OP_IS_LOAD_MODE 42
+#define EVENT_OP_IS_SPEC_REF 41
+#define EVENT_OP_IS_CRIT_REF 40
+#define EVENT_OP_IS_REFRESH 39
+#define EVENT_OP_IS_ENTER_MPSM 35
+#define EVENT_OP_IS_ENTER_POWERDOWN 31
+#define EVENT_OP_IS_ENTER_SELFREF 27
+#define EVENT_WAW_HAZARD 26
+#define EVENT_RAW_HAZARD 25
+#define EVENT_WAR_HAZARD 24
+#define EVENT_WRITE_COMBINE 23
+#define EVENT_RDWR_TRANSITIONS 22
+#define EVENT_PRECHARGE_FOR_OTHER 21
+#define EVENT_PRECHARGE_FOR_RDWR 20
+#define EVENT_OP_IS_PRECHARGE 19
+#define EVENT_OP_IS_MWR 18
+#define EVENT_OP_IS_WR 17
+#define EVENT_OP_IS_RD 16
+#define EVENT_OP_IS_RD_ACTIVATE 15
+#define EVENT_OP_IS_RD_OR_WR 14
+#define EVENT_OP_IS_ACTIVATE 13
+#define EVENT_WR_XACT_WHEN_CRITICAL 12
+#define EVENT_LPR_XACT_WHEN_CRITICAL 11
+#define EVENT_HPR_XACT_WHEN_CRITICAL 10
+#define EVENT_DFI_RD_DATA_CYCLES 9
+#define EVENT_DFI_WR_DATA_CYCLES 8
+#define EVENT_ACT_BYPASS 7
+#define EVENT_READ_BYPASS 6
+#define EVENT_HIF_HI_PRI_RD 5
+#define EVENT_HIF_RMW 4
+#define EVENT_HIF_RD 3
+#define EVENT_HIF_WR 2
+#define EVENT_HIF_RD_OR_WR 1
+
+/* Event counter value registers */
+#define DDRC_PERF_CNT_VALUE_BASE 0x8080
+#define DDRC_PERF_CNT_VALUE(n) (DDRC_PERF_CNT_VALUE_BASE + 8 * (n))
+
+/* Fixed event counter enable/disable register */
+#define DDRC_PERF_CNT_FREERUN_EN 0x80C0
+#define DDRC_PERF_FREERUN_WRITE_EN 0x1
+#define DDRC_PERF_FREERUN_READ_EN 0x2
+
+/* Fixed event counter control register */
+#define DDRC_PERF_CNT_FREERUN_CTRL 0x80C8
+#define DDRC_FREERUN_WRITE_CNT_CLR 0x1
+#define DDRC_FREERUN_READ_CNT_CLR 0x2
+
+/* Fixed event counter value register */
+#define DDRC_PERF_CNT_VALUE_WR_OP 0x80D0
+#define DDRC_PERF_CNT_VALUE_RD_OP 0x80D8
+#define DDRC_PERF_CNT_VALUE_OVERFLOW BIT_ULL(48)
+#define DDRC_PERF_CNT_MAX_VALUE GENMASK_ULL(48, 0)
+
+struct cn10k_ddr_pmu {
+ struct pmu pmu;
+ void __iomem *base;
+ unsigned int cpu;
+ struct device *dev;
+ int active_events;
+ struct perf_event *events[DDRC_PERF_NUM_COUNTERS];
+};
+
+#define to_cn10k_ddr_pmu(p) container_of(p, struct cn10k_ddr_pmu, pmu)
+
+static ssize_t cn10k_ddr_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 CN10K_DDR_PMU_EVENT_ATTR(_name, _id) \
+ PMU_EVENT_ATTR_ID(_name, cn10k_ddr_pmu_event_show, _id)
+
+static struct attribute *cn10k_ddr_perf_events_attrs[] = {
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hif_rd_or_wr_access, EVENT_HIF_RD_OR_WR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hif_wr_access, EVENT_HIF_WR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hif_rd_access, EVENT_HIF_RD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hif_rmw_access, EVENT_HIF_RMW),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hif_pri_rdaccess, EVENT_HIF_HI_PRI_RD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_rd_bypass_access, EVENT_READ_BYPASS),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_act_bypass_access, EVENT_ACT_BYPASS),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_dif_wr_data_access, EVENT_DFI_WR_DATA_CYCLES),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_dif_rd_data_access, EVENT_DFI_RD_DATA_CYCLES),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hpri_sched_rd_crit_access,
+ EVENT_HPR_XACT_WHEN_CRITICAL),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_lpri_sched_rd_crit_access,
+ EVENT_LPR_XACT_WHEN_CRITICAL),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_wr_trxn_crit_access,
+ EVENT_WR_XACT_WHEN_CRITICAL),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_active_access, EVENT_OP_IS_ACTIVATE),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_rd_or_wr_access, EVENT_OP_IS_RD_OR_WR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_rd_active_access, EVENT_OP_IS_RD_ACTIVATE),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_read, EVENT_OP_IS_RD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_write, EVENT_OP_IS_WR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_mwr, EVENT_OP_IS_MWR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_precharge, EVENT_OP_IS_PRECHARGE),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_precharge_for_rdwr, EVENT_PRECHARGE_FOR_RDWR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_precharge_for_other,
+ EVENT_PRECHARGE_FOR_OTHER),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_rdwr_transitions, EVENT_RDWR_TRANSITIONS),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_write_combine, EVENT_WRITE_COMBINE),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_war_hazard, EVENT_WAR_HAZARD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_raw_hazard, EVENT_RAW_HAZARD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_waw_hazard, EVENT_WAW_HAZARD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_enter_selfref, EVENT_OP_IS_ENTER_SELFREF),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_enter_powerdown, EVENT_OP_IS_ENTER_POWERDOWN),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_enter_mpsm, EVENT_OP_IS_ENTER_MPSM),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_refresh, EVENT_OP_IS_REFRESH),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_crit_ref, EVENT_OP_IS_CRIT_REF),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_spec_ref, EVENT_OP_IS_SPEC_REF),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_load_mode, EVENT_OP_IS_LOAD_MODE),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_zqcl, EVENT_OP_IS_ZQCL),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_cam_wr_access, EVENT_OP_IS_ZQCS),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_hpr_req_with_nocredit,
+ EVENT_HPR_REQ_WITH_NOCREDIT),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_lpr_req_with_nocredit,
+ EVENT_LPR_REQ_WITH_NOCREDIT),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_bsm_alloc, EVENT_BSM_ALLOC),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_bsm_starvation, EVENT_BSM_STARVATION),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_win_limit_reached_rd,
+ EVENT_VISIBLE_WIN_LIMIT_REACHED_RD),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_win_limit_reached_wr,
+ EVENT_VISIBLE_WIN_LIMIT_REACHED_WR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_dqsosc_mpc, EVENT_OP_IS_DQSOSC_MPC),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_dqsosc_mrr, EVENT_OP_IS_DQSOSC_MRR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_tcr_mrr, EVENT_OP_IS_TCR_MRR),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_zqstart, EVENT_OP_IS_ZQSTART),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_zqlatch, EVENT_OP_IS_ZQLATCH),
+ /* Free run event counters */
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_ddr_reads, EVENT_DDR_READS),
+ CN10K_DDR_PMU_EVENT_ATTR(ddr_ddr_writes, EVENT_DDR_WRITES),
+ NULL
+};
+
+static struct attribute_group cn10k_ddr_perf_events_attr_group = {
+ .name = "events",
+ .attrs = cn10k_ddr_perf_events_attrs,
+};
+
+PMU_FORMAT_ATTR(event, "config:0-8");
+
+static struct attribute *cn10k_ddr_perf_format_attrs[] = {
+ &format_attr_event.attr,
+ NULL,
+};
+
+static struct attribute_group cn10k_ddr_perf_format_attr_group = {
+ .name = "format",
+ .attrs = cn10k_ddr_perf_format_attrs,
+};
+
+static ssize_t cn10k_ddr_perf_cpumask_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct cn10k_ddr_pmu *pmu = dev_get_drvdata(dev);
+
+ return cpumap_print_to_pagebuf(true, buf, cpumask_of(pmu->cpu));
+}
+
+static struct device_attribute cn10k_ddr_perf_cpumask_attr =
+ __ATTR(cpumask, 0444, cn10k_ddr_perf_cpumask_show, NULL);
+
+static struct attribute *cn10k_ddr_perf_cpumask_attrs[] = {
+ &cn10k_ddr_perf_cpumask_attr.attr,
+ NULL,
+};
+
+static struct attribute_group cn10k_ddr_perf_cpumask_attr_group = {
+ .attrs = cn10k_ddr_perf_cpumask_attrs,
+};
+
+static const struct attribute_group *cn10k_attr_groups[] = {
+ &cn10k_ddr_perf_events_attr_group,
+ &cn10k_ddr_perf_format_attr_group,
+ &cn10k_ddr_perf_cpumask_attr_group,
+ NULL,
+};
+
+static int ddr_perf_get_event_bitmap(int eventid, u64 *event_bitmap)
+{
+ switch (eventid) {
+ case EVENT_HIF_RD_OR_WR ... EVENT_WAW_HAZARD:
+ case EVENT_OP_IS_REFRESH ... EVENT_OP_IS_ZQLATCH:
+ *event_bitmap = (1ULL << (eventid - 1));
+ break;
+ case EVENT_OP_IS_ENTER_SELFREF:
+ case EVENT_OP_IS_ENTER_POWERDOWN:
+ case EVENT_OP_IS_ENTER_MPSM:
+ *event_bitmap = (0xFULL << (eventid - 1));
+ break;
+ default:
+ pr_err("%s Invalid eventid %d\n", __func__, eventid);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int cn10k_ddr_perf_alloc_counter(struct cn10k_ddr_pmu *pmu,
+ struct perf_event *event)
+{
+ u8 config = event->attr.config;
+ int i;
+
+ /* DDR read free-run counter index */
+ if (config == EVENT_DDR_READS) {
+ pmu->events[DDRC_PERF_READ_COUNTER_IDX] = event;
+ return DDRC_PERF_READ_COUNTER_IDX;
+ }
+
+ /* DDR write free-run counter index */
+ if (config == EVENT_DDR_WRITES) {
+ pmu->events[DDRC_PERF_WRITE_COUNTER_IDX] = event;
+ return DDRC_PERF_WRITE_COUNTER_IDX;
+ }
+
+ /* Allocate DDR generic counters */
+ for (i = 0; i < DDRC_PERF_NUM_GEN_COUNTERS; i++) {
+ if (pmu->events[i] == NULL) {
+ pmu->events[i] = event;
+ return i;
+ }
+ }
+
+ return -ENOENT;
+}
+
+static void cn10k_ddr_perf_free_counter(struct cn10k_ddr_pmu *pmu, int counter)
+{
+ pmu->events[counter] = NULL;
+}
+
+static int cn10k_ddr_perf_event_init(struct perf_event *event)
+{
+ struct cn10k_ddr_pmu *pmu = to_cn10k_ddr_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+
+ if (event->attr.type != event->pmu->type)
+ return -ENOENT;
+
+ if (is_sampling_event(event)) {
+ dev_info(pmu->dev, "Sampling not supported!\n");
+ return -EOPNOTSUPP;
+ }
+
+ if (event->cpu < 0) {
+ dev_warn(pmu->dev, "Can't provide per-task data!\n");
+ return -EOPNOTSUPP;
+ }
+
+ /* We must NOT create groups containing mixed PMUs */
+ if (event->group_leader->pmu != event->pmu &&
+ !is_software_event(event->group_leader))
+ return -EINVAL;
+
+ /* Set ownership of event to one CPU, same event can not be observed
+ * on multiple cpus at same time.
+ */
+ event->cpu = pmu->cpu;
+ hwc->idx = -1;
+ return 0;
+}
+
+static void cn10k_ddr_perf_counter_enable(struct cn10k_ddr_pmu *pmu,
+ int counter, bool enable)
+{
+ u32 reg;
+ u64 val;
+
+ if (counter > DDRC_PERF_NUM_COUNTERS) {
+ pr_err("Error: unsupported counter %d\n", counter);
+ return;
+ }
+
+ if (counter < DDRC_PERF_NUM_GEN_COUNTERS) {
+ reg = DDRC_PERF_CFG(counter);
+ val = readq_relaxed(pmu->base + reg);
+
+ if (enable)
+ val |= EVENT_ENABLE;
+ else
+ val &= ~EVENT_ENABLE;
+
+ writeq_relaxed(val, pmu->base + reg);
+ } else {
+ val = readq_relaxed(pmu->base + DDRC_PERF_CNT_FREERUN_EN);
+ if (enable) {
+ if (counter == DDRC_PERF_READ_COUNTER_IDX)
+ val |= DDRC_PERF_FREERUN_READ_EN;
+ else
+ val |= DDRC_PERF_FREERUN_WRITE_EN;
+ } else {
+ if (counter == DDRC_PERF_READ_COUNTER_IDX)
+ val &= ~DDRC_PERF_FREERUN_READ_EN;
+ else
+ val &= ~DDRC_PERF_FREERUN_WRITE_EN;
+ }
+ writeq_relaxed(val, pmu->base + DDRC_PERF_CNT_FREERUN_EN);
+ }
+}
+
+static u64 cn10k_ddr_perf_read_counter(struct cn10k_ddr_pmu *pmu, int counter)
+{
+ u64 val;
+
+ if (counter == DDRC_PERF_READ_COUNTER_IDX)
+ return readq_relaxed(pmu->base + DDRC_PERF_CNT_VALUE_RD_OP);
+
+ if (counter == DDRC_PERF_WRITE_COUNTER_IDX)
+ return readq_relaxed(pmu->base + DDRC_PERF_CNT_VALUE_WR_OP);
+
+ val = readq_relaxed(pmu->base + DDRC_PERF_CNT_VALUE(counter));
+ return val;
+}
+
+static void cn10k_ddr_perf_event_update(struct perf_event *event)
+{
+ struct cn10k_ddr_pmu *pmu = to_cn10k_ddr_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ u64 prev_count, new_count, mask;
+
+ do {
+ prev_count = local64_read(&hwc->prev_count);
+ new_count = cn10k_ddr_perf_read_counter(pmu, hwc->idx);
+ } while (local64_xchg(&hwc->prev_count, new_count) != prev_count);
+
+ mask = DDRC_PERF_CNT_MAX_VALUE;
+
+ local64_add((new_count - prev_count) & mask, &event->count);
+}
+
+static void cn10k_ddr_perf_event_start(struct perf_event *event, int flags)
+{
+ struct cn10k_ddr_pmu *pmu = to_cn10k_ddr_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int counter = hwc->idx;
+
+ local64_set(&hwc->prev_count, 0);
+
+ cn10k_ddr_perf_counter_enable(pmu, counter, true);
+
+ hwc->state = 0;
+}
+
+static int cn10k_ddr_perf_event_add(struct perf_event *event, int flags)
+{
+ struct cn10k_ddr_pmu *pmu = to_cn10k_ddr_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ u8 config = event->attr.config;
+ int counter, ret;
+ u32 reg_offset;
+ u64 val;
+
+ counter = cn10k_ddr_perf_alloc_counter(pmu, event);
+ if (counter < 0)
+ return -EAGAIN;
+
+ pmu->active_events++;
+ hwc->idx = counter;
+
+ if (counter < DDRC_PERF_NUM_GEN_COUNTERS) {
+ /* Generic counters, configure event id */
+ reg_offset = DDRC_PERF_CFG(counter);
+ ret = ddr_perf_get_event_bitmap(config, &val);
+ if (ret)
+ return ret;
+
+ writeq_relaxed(val, pmu->base + reg_offset);
+ } else {
+ /* fixed event counter, clear counter value */
+ if (counter == DDRC_PERF_READ_COUNTER_IDX)
+ val = DDRC_FREERUN_READ_CNT_CLR;
+ else
+ val = DDRC_FREERUN_WRITE_CNT_CLR;
+
+ writeq_relaxed(val, pmu->base + DDRC_PERF_CNT_FREERUN_CTRL);
+ }
+
+ hwc->state |= PERF_HES_STOPPED;
+
+ if (flags & PERF_EF_START)
+ cn10k_ddr_perf_event_start(event, flags);
+
+ return 0;
+}
+
+static void cn10k_ddr_perf_event_stop(struct perf_event *event, int flags)
+{
+ struct cn10k_ddr_pmu *pmu = to_cn10k_ddr_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int counter = hwc->idx;
+
+ cn10k_ddr_perf_counter_enable(pmu, counter, false);
+
+ if (flags & PERF_EF_UPDATE)
+ cn10k_ddr_perf_event_update(event);
+
+ hwc->state |= PERF_HES_STOPPED;
+}
+
+static void cn10k_ddr_perf_event_del(struct perf_event *event, int flags)
+{
+ struct cn10k_ddr_pmu *pmu = to_cn10k_ddr_pmu(event->pmu);
+ struct hw_perf_event *hwc = &event->hw;
+ int counter = hwc->idx;
+
+ cn10k_ddr_perf_event_stop(event, PERF_EF_UPDATE);
+
+ cn10k_ddr_perf_free_counter(pmu, counter);
+ pmu->active_events--;
+ hwc->idx = -1;
+}
+
+static void cn10k_ddr_perf_pmu_enable(struct pmu *pmu)
+{
+ struct cn10k_ddr_pmu *ddr_pmu = to_cn10k_ddr_pmu(pmu);
+
+ writeq_relaxed(START_OP_CTRL_VAL_START, ddr_pmu->base +
+ DDRC_PERF_CNT_START_OP_CTRL);
+}
+
+static void cn10k_ddr_perf_pmu_disable(struct pmu *pmu)
+{
+ struct cn10k_ddr_pmu *ddr_pmu = to_cn10k_ddr_pmu(pmu);
+
+ writeq_relaxed(END_OP_CTRL_VAL_END, ddr_pmu->base +
+ DDRC_PERF_CNT_END_OP_CTRL);
+}
+
+static int cn10k_ddr_perf_probe(struct platform_device *pdev)
+{
+ struct cn10k_ddr_pmu *ddr_pmu;
+ struct resource *res;
+ void __iomem *base;
+ char *name;
+ int ret;
+
+ ddr_pmu = devm_kzalloc(&pdev->dev, sizeof(*ddr_pmu), GFP_KERNEL);
+ if (!ddr_pmu)
+ return -ENOMEM;
+
+ ddr_pmu->dev = &pdev->dev;
+ platform_set_drvdata(pdev, ddr_pmu);
+
+ base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ ddr_pmu->base = base;
+
+ /* Setup the PMU counter to work in manual mode */
+ writeq_relaxed(OP_MODE_CTRL_VAL_MANNUAL, ddr_pmu->base +
+ DDRC_PERF_CNT_OP_MODE_CTRL);
+
+ ddr_pmu->pmu = (struct pmu) {
+ .module = THIS_MODULE,
+ .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
+ .task_ctx_nr = perf_invalid_context,
+ .attr_groups = cn10k_attr_groups,
+ .event_init = cn10k_ddr_perf_event_init,
+ .add = cn10k_ddr_perf_event_add,
+ .del = cn10k_ddr_perf_event_del,
+ .start = cn10k_ddr_perf_event_start,
+ .stop = cn10k_ddr_perf_event_stop,
+ .read = cn10k_ddr_perf_event_update,
+ .pmu_enable = cn10k_ddr_perf_pmu_enable,
+ .pmu_disable = cn10k_ddr_perf_pmu_disable,
+ };
+
+ /* Choose this cpu to collect perf data */
+ ddr_pmu->cpu = raw_smp_processor_id();
+
+ name = devm_kasprintf(ddr_pmu->dev, GFP_KERNEL, "mrvl_ddr_pmu_%llx",
+ res->start);
+ if (!name)
+ return -ENOMEM;
+
+ ret = perf_pmu_register(&ddr_pmu->pmu, name, -1);
+ if (ret)
+ return ret;
+
+ pr_info("CN10K DDR PMU Driver for ddrc@%llx\n", res->start);
+ return 0;
+}
+
+static int cn10k_ddr_perf_remove(struct platform_device *pdev)
+{
+ struct cn10k_ddr_pmu *ddr_pmu = platform_get_drvdata(pdev);
+
+ perf_pmu_unregister(&ddr_pmu->pmu);
+ return 0;
+}
+
+static const struct of_device_id cn10k_ddr_pmu_of_match[] = {
+ { .compatible = "marvell,cn10k-ddr-pmu", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, cn10k_ddr_pmu_of_match);
+
+static struct platform_driver cn10k_ddr_pmu_driver = {
+ .driver = {
+ .name = "cn10k-ddr-pmu",
+ .of_match_table = cn10k_ddr_pmu_of_match,
+ .suppress_bind_attrs = true,
+ },
+ .probe = cn10k_ddr_perf_probe,
+ .remove = cn10k_ddr_perf_remove,
+};
+
+static int __init cn10k_ddr_pmu_init(void)
+{
+ return platform_driver_register(&cn10k_ddr_pmu_driver);
+}
+
+static void __exit cn10k_ddr_pmu_exit(void)
+{
+ platform_driver_unregister(&cn10k_ddr_pmu_driver);
+}
+
+module_init(cn10k_ddr_pmu_init);
+module_exit(cn10k_ddr_pmu_exit);
+
+MODULE_AUTHOR("Bharat Bhushan <[email protected]>");
+MODULE_LICENSE("GPL v2");
--
2.17.1
As DDR perf event counters are not per core, so they should be accessed
only by one core at a time. Select new core when previously owning core
is going offline.
Signed-off-by: Bharat Bhushan <[email protected]>
---
v1->v6
- No Change
drivers/perf/marvell_cn10k_ddr_pmu.c | 50 ++++++++++++++++++++++++++--
include/linux/cpuhotplug.h | 1 +
2 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/drivers/perf/marvell_cn10k_ddr_pmu.c b/drivers/perf/marvell_cn10k_ddr_pmu.c
index 21fccb9090c5..bef0cee3a46a 100644
--- a/drivers/perf/marvell_cn10k_ddr_pmu.c
+++ b/drivers/perf/marvell_cn10k_ddr_pmu.c
@@ -129,6 +129,7 @@ struct cn10k_ddr_pmu {
int active_events;
struct perf_event *events[DDRC_PERF_NUM_COUNTERS];
struct hrtimer hrtimer;
+ struct hlist_node node;
};
#define to_cn10k_ddr_pmu(p) container_of(p, struct cn10k_ddr_pmu, pmu)
@@ -610,6 +611,24 @@ static enum hrtimer_restart cn10k_ddr_pmu_timer_handler(struct hrtimer *hrtimer)
return HRTIMER_RESTART;
}
+static int cn10k_ddr_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
+{
+ struct cn10k_ddr_pmu *pmu = hlist_entry_safe(node, struct cn10k_ddr_pmu,
+ node);
+ unsigned int target;
+
+ if (cpu != pmu->cpu)
+ return 0;
+
+ target = cpumask_any_but(cpu_online_mask, cpu);
+ if (target >= nr_cpu_ids)
+ return 0;
+
+ perf_pmu_migrate_context(&pmu->pmu, cpu, target);
+ pmu->cpu = target;
+ return 0;
+}
+
static int cn10k_ddr_perf_probe(struct platform_device *pdev)
{
struct cn10k_ddr_pmu *ddr_pmu;
@@ -661,18 +680,31 @@ static int cn10k_ddr_perf_probe(struct platform_device *pdev)
hrtimer_init(&ddr_pmu->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
ddr_pmu->hrtimer.function = cn10k_ddr_pmu_timer_handler;
+ cpuhp_state_add_instance_nocalls(
+ CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
+ &ddr_pmu->node);
+
ret = perf_pmu_register(&ddr_pmu->pmu, name, -1);
if (ret)
- return ret;
+ goto error;
pr_info("CN10K DDR PMU Driver for ddrc@%llx\n", res->start);
return 0;
+error:
+ cpuhp_state_remove_instance_nocalls(
+ CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
+ &ddr_pmu->node);
+ return ret;
}
static int cn10k_ddr_perf_remove(struct platform_device *pdev)
{
struct cn10k_ddr_pmu *ddr_pmu = platform_get_drvdata(pdev);
+ cpuhp_state_remove_instance_nocalls(
+ CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
+ &ddr_pmu->node);
+
perf_pmu_unregister(&ddr_pmu->pmu);
return 0;
}
@@ -695,12 +727,26 @@ static struct platform_driver cn10k_ddr_pmu_driver = {
static int __init cn10k_ddr_pmu_init(void)
{
- return platform_driver_register(&cn10k_ddr_pmu_driver);
+ int ret;
+
+ ret = cpuhp_setup_state_multi(
+ CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
+ "perf/marvell/cn10k/ddr:online", NULL,
+ cn10k_ddr_pmu_offline_cpu);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&cn10k_ddr_pmu_driver);
+ if (ret)
+ cpuhp_remove_multi_state(
+ CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE);
+ return ret;
}
static void __exit cn10k_ddr_pmu_exit(void)
{
platform_driver_unregister(&cn10k_ddr_pmu_driver);
+ cpuhp_remove_multi_state(CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE);
}
module_init(cn10k_ddr_pmu_init);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 832d8a74fa59..a4b521f12b58 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -227,6 +227,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
+ CPUHP_AP_PERF_ARM_MARVELL_CN10K_DDR_ONLINE,
CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
--
2.17.1
CN10k DSS h/w perfmon does not support event overflow interrupt, so
periodic timer is being used. Each event counter is 48bit, which in worst
case scenario can increment at maximum 5.6 GT/s. At this rate it may take
many hours to overflow these counters. Therefore polling period for
overflow is set to 100 sec, which can be changed using sysfs parameter.
Two fixed event counters starts counting from zero on overflow, so
overflow condition is when new count less than previous count. While
eight programmable event counters freezes at maximum value. Also individual
counter cannot be restarted, so need to restart all eight counters.
Signed-off-by: Bharat Bhushan <[email protected]>
---
v3->v6
- No Change
v2->v3:
- uintXX_t -> uXX
v1->v2:
- No Change
drivers/perf/marvell_cn10k_ddr_pmu.c | 111 +++++++++++++++++++++++++++
1 file changed, 111 insertions(+)
diff --git a/drivers/perf/marvell_cn10k_ddr_pmu.c b/drivers/perf/marvell_cn10k_ddr_pmu.c
index 9b6d5e716b94..21fccb9090c5 100644
--- a/drivers/perf/marvell_cn10k_ddr_pmu.c
+++ b/drivers/perf/marvell_cn10k_ddr_pmu.c
@@ -11,6 +11,7 @@
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/perf_event.h>
+#include <linux/hrtimer.h>
/* Performance Counters Operating Mode Control Registers */
#define DDRC_PERF_CNT_OP_MODE_CTRL 0x8020
@@ -127,6 +128,7 @@ struct cn10k_ddr_pmu {
struct device *dev;
int active_events;
struct perf_event *events[DDRC_PERF_NUM_COUNTERS];
+ struct hrtimer hrtimer;
};
#define to_cn10k_ddr_pmu(p) container_of(p, struct cn10k_ddr_pmu, pmu)
@@ -251,6 +253,18 @@ static const struct attribute_group *cn10k_attr_groups[] = {
NULL,
};
+/* Default poll timeout is 100 sec, which is very sufficient for
+ * 48 bit counter incremented max at 5.6 GT/s, which may take many
+ * hours to overflow.
+ */
+static unsigned long cn10k_ddr_pmu_poll_period_sec = 100;
+module_param_named(poll_period_sec, cn10k_ddr_pmu_poll_period_sec, ulong, 0644);
+
+static ktime_t cn10k_ddr_pmu_timer_period(void)
+{
+ return ms_to_ktime((u64)cn10k_ddr_pmu_poll_period_sec * USEC_PER_SEC);
+}
+
static int ddr_perf_get_event_bitmap(int eventid, u64 *event_bitmap)
{
switch (eventid) {
@@ -433,6 +447,10 @@ static int cn10k_ddr_perf_event_add(struct perf_event *event, int flags)
pmu->active_events++;
hwc->idx = counter;
+ if (pmu->active_events == 1)
+ hrtimer_start(&pmu->hrtimer, cn10k_ddr_pmu_timer_period(),
+ HRTIMER_MODE_REL_PINNED);
+
if (counter < DDRC_PERF_NUM_GEN_COUNTERS) {
/* Generic counters, configure event id */
reg_offset = DDRC_PERF_CFG(counter);
@@ -484,6 +502,10 @@ static void cn10k_ddr_perf_event_del(struct perf_event *event, int flags)
cn10k_ddr_perf_free_counter(pmu, counter);
pmu->active_events--;
hwc->idx = -1;
+
+ /* Cancel timer when no events to capture */
+ if (pmu->active_events == 0)
+ hrtimer_cancel(&pmu->hrtimer);
}
static void cn10k_ddr_perf_pmu_enable(struct pmu *pmu)
@@ -502,6 +524,92 @@ static void cn10k_ddr_perf_pmu_disable(struct pmu *pmu)
DDRC_PERF_CNT_END_OP_CTRL);
}
+static void cn10k_ddr_perf_event_update_all(struct cn10k_ddr_pmu *pmu)
+{
+ struct hw_perf_event *hwc;
+ int i;
+
+ for (i = 0; i < DDRC_PERF_NUM_GEN_COUNTERS; i++) {
+ if (pmu->events[i] == NULL)
+ continue;
+
+ cn10k_ddr_perf_event_update(pmu->events[i]);
+ }
+
+ /* Reset previous count as h/w counter are reset */
+ for (i = 0; i < DDRC_PERF_NUM_GEN_COUNTERS; i++) {
+ if (pmu->events[i] == NULL)
+ continue;
+
+ hwc = &pmu->events[i]->hw;
+ local64_set(&hwc->prev_count, 0);
+ }
+}
+
+static irqreturn_t cn10k_ddr_pmu_overflow_handler(struct cn10k_ddr_pmu *pmu)
+{
+ struct perf_event *event;
+ struct hw_perf_event *hwc;
+ u64 prev_count, new_count;
+ u64 value;
+ int i;
+
+ event = pmu->events[DDRC_PERF_READ_COUNTER_IDX];
+ if (event) {
+ hwc = &event->hw;
+ prev_count = local64_read(&hwc->prev_count);
+ new_count = cn10k_ddr_perf_read_counter(pmu, hwc->idx);
+
+ /* Overflow condition is when new count less than
+ * previous count
+ */
+ if (new_count < prev_count)
+ cn10k_ddr_perf_event_update(event);
+ }
+
+ event = pmu->events[DDRC_PERF_WRITE_COUNTER_IDX];
+ if (event) {
+ hwc = &event->hw;
+ prev_count = local64_read(&hwc->prev_count);
+ new_count = cn10k_ddr_perf_read_counter(pmu, hwc->idx);
+
+ /* Overflow condition is when new count less than
+ * previous count
+ */
+ if (new_count < prev_count)
+ cn10k_ddr_perf_event_update(event);
+ }
+
+ for (i = 0; i < DDRC_PERF_NUM_GEN_COUNTERS; i++) {
+ if (pmu->events[i] == NULL)
+ continue;
+
+ value = cn10k_ddr_perf_read_counter(pmu, i);
+ if (value == DDRC_PERF_CNT_MAX_VALUE) {
+ pr_info("Counter-(%d) reached max value\n", i);
+ cn10k_ddr_perf_event_update_all(pmu);
+ cn10k_ddr_perf_pmu_disable(&pmu->pmu);
+ cn10k_ddr_perf_pmu_enable(&pmu->pmu);
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+static enum hrtimer_restart cn10k_ddr_pmu_timer_handler(struct hrtimer *hrtimer)
+{
+ struct cn10k_ddr_pmu *pmu = container_of(hrtimer, struct cn10k_ddr_pmu,
+ hrtimer);
+ unsigned long flags;
+
+ local_irq_save(flags);
+ cn10k_ddr_pmu_overflow_handler(pmu);
+ local_irq_restore(flags);
+
+ hrtimer_forward_now(hrtimer, cn10k_ddr_pmu_timer_period());
+ return HRTIMER_RESTART;
+}
+
static int cn10k_ddr_perf_probe(struct platform_device *pdev)
{
struct cn10k_ddr_pmu *ddr_pmu;
@@ -550,6 +658,9 @@ static int cn10k_ddr_perf_probe(struct platform_device *pdev)
if (!name)
return -ENOMEM;
+ hrtimer_init(&ddr_pmu->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ ddr_pmu->hrtimer.function = cn10k_ddr_pmu_timer_handler;
+
ret = perf_pmu_register(&ddr_pmu->pmu, name, -1);
if (ret)
return ret;
--
2.17.1
On Fri, Oct 29, 2021 at 05:26:43PM +0530, Bharat Bhushan wrote:
> As DDR perf event counters are not per core, so they should be accessed
> only by one core at a time. Select new core when previously owning core
> is going offline.
>
> Signed-off-by: Bharat Bhushan <[email protected]>
> ---
> v1->v6
> - No Change
>
> drivers/perf/marvell_cn10k_ddr_pmu.c | 50 ++++++++++++++++++++++++++--
> include/linux/cpuhotplug.h | 1 +
> 2 files changed, 49 insertions(+), 2 deletions(-)
I don't think the driver is much use without this patch, so please can you
move the Kconfig stuff to a patch at the end so that the driver can't be
enabled in a broken state half way through the series?
Will
> -----Original Message-----
> From: Will Deacon <[email protected]>
> Sent: Tuesday, December 14, 2021 5:55 PM
> To: Bharat Bhushan <[email protected]>
> Cc: [email protected]; [email protected]; Bhaskara Budiredla
> <[email protected]>; Sunil Kovvuri Goutham <[email protected]>;
> [email protected]; [email protected]; linux-
> [email protected]
> Subject: [EXT] Re: [PATCH v6 4/4] perf/marvell: cn10k DDR perf event core
> ownership
>
> External Email
>
> ----------------------------------------------------------------------
> On Fri, Oct 29, 2021 at 05:26:43PM +0530, Bharat Bhushan wrote:
> > As DDR perf event counters are not per core, so they should be
> > accessed only by one core at a time. Select new core when previously
> > owning core is going offline.
> >
> > Signed-off-by: Bharat Bhushan <[email protected]>
> > ---
> > v1->v6
> > - No Change
> >
> > drivers/perf/marvell_cn10k_ddr_pmu.c | 50 ++++++++++++++++++++++++++--
> > include/linux/cpuhotplug.h | 1 +
> > 2 files changed, 49 insertions(+), 2 deletions(-)
>
> I don't think the driver is much use without this patch, so please can you move
> the Kconfig stuff to a patch at the end so that the driver can't be enabled in a
> broken state half way through the series?
Okay, will change.
Thanks
-Bharat
>
> Will