mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Waiman Long](/assets/img/avatar_default.png)
The following circular locking dependency was reported when running cpus online/offline test on an arm64 system. [ 84.195923] Chain exists of: dmc620_pmu_irqs_lock --> cpu_hotplug_lock --> cpuhp_state-down [ 84.207305] Possible unsafe locking scenario: [ 84.213212] CPU0 CPU1 [ 84.217729] ---- ---- [ 84.222247] lock(cpuhp_state-down); [ 84.225899] lock(cpu_hotplug_lock); [ 84.232068] lock(cpuhp_state-down); [ 84.238237] lock(dmc620_pmu_irqs_lock); [ 84.242236] *** DEADLOCK *** The following locking order happens when dmc620_pmu_get_irq() calls cpuhp_state_add_instance_nocalls(). lock(dmc620_pmu_irqs_lock) --> lock(cpu_hotplug_lock) On the other hand, the calling sequence cpuhp_thread_fun() => cpuhp_invoke_callback() => dmc620_pmu_cpu_teardown() leads to the locking sequence lock(cpuhp_state-down) => lock(dmc620_pmu_irqs_lock) Here dmc620_pmu_irqs_lock protects both the dmc620_pmu_irqs and the pmus_node lists in various dmc620_pmu instances. dmc620_pmu_get_irq() requires protected access to dmc620_pmu_irqs whereas dmc620_pmu_cpu_teardown() needs protection to the pmus_node lists. Break this circular locking dependency by using two separate locks to protect dmc620_pmu_irqs list and the pmus_node lists respectively. Suggested-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20230812235549.494174-1-longman@redhat.com Signed-off-by: Will Deacon <will@kernel.org>
783 lines
22 KiB
C
783 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* ARM DMC-620 memory controller PMU driver
|
|
*
|
|
* Copyright (C) 2020 Ampere Computing LLC.
|
|
*/
|
|
|
|
#define DMC620_PMUNAME "arm_dmc620"
|
|
#define DMC620_DRVNAME DMC620_PMUNAME "_pmu"
|
|
#define pr_fmt(fmt) DMC620_DRVNAME ": " fmt
|
|
|
|
#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/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/perf_event.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/printk.h>
|
|
#include <linux/rculist.h>
|
|
#include <linux/refcount.h>
|
|
|
|
#define DMC620_PA_SHIFT 12
|
|
#define DMC620_CNT_INIT 0x80000000
|
|
#define DMC620_CNT_MAX_PERIOD 0xffffffff
|
|
#define DMC620_PMU_CLKDIV2_MAX_COUNTERS 8
|
|
#define DMC620_PMU_CLK_MAX_COUNTERS 2
|
|
#define DMC620_PMU_MAX_COUNTERS \
|
|
(DMC620_PMU_CLKDIV2_MAX_COUNTERS + DMC620_PMU_CLK_MAX_COUNTERS)
|
|
|
|
/*
|
|
* The PMU registers start at 0xA00 in the DMC-620 memory map, and these
|
|
* offsets are relative to that base.
|
|
*
|
|
* Each counter has a group of control/value registers, and the
|
|
* DMC620_PMU_COUNTERn offsets are within a counter group.
|
|
*
|
|
* The counter registers groups start at 0xA10.
|
|
*/
|
|
#define DMC620_PMU_OVERFLOW_STATUS_CLKDIV2 0x8
|
|
#define DMC620_PMU_OVERFLOW_STATUS_CLKDIV2_MASK \
|
|
(DMC620_PMU_CLKDIV2_MAX_COUNTERS - 1)
|
|
#define DMC620_PMU_OVERFLOW_STATUS_CLK 0xC
|
|
#define DMC620_PMU_OVERFLOW_STATUS_CLK_MASK \
|
|
(DMC620_PMU_CLK_MAX_COUNTERS - 1)
|
|
#define DMC620_PMU_COUNTERS_BASE 0x10
|
|
#define DMC620_PMU_COUNTERn_MASK_31_00 0x0
|
|
#define DMC620_PMU_COUNTERn_MASK_63_32 0x4
|
|
#define DMC620_PMU_COUNTERn_MATCH_31_00 0x8
|
|
#define DMC620_PMU_COUNTERn_MATCH_63_32 0xC
|
|
#define DMC620_PMU_COUNTERn_CONTROL 0x10
|
|
#define DMC620_PMU_COUNTERn_CONTROL_ENABLE BIT(0)
|
|
#define DMC620_PMU_COUNTERn_CONTROL_INVERT BIT(1)
|
|
#define DMC620_PMU_COUNTERn_CONTROL_EVENT_MUX GENMASK(6, 2)
|
|
#define DMC620_PMU_COUNTERn_CONTROL_INCR_MUX GENMASK(8, 7)
|
|
#define DMC620_PMU_COUNTERn_VALUE 0x20
|
|
/* Offset of the registers for a given counter, relative to 0xA00 */
|
|
#define DMC620_PMU_COUNTERn_OFFSET(n) \
|
|
(DMC620_PMU_COUNTERS_BASE + 0x28 * (n))
|
|
|
|
/*
|
|
* dmc620_pmu_irqs_lock: protects dmc620_pmu_irqs list
|
|
* dmc620_pmu_node_lock: protects pmus_node lists in all dmc620_pmu instances
|
|
*/
|
|
static DEFINE_MUTEX(dmc620_pmu_irqs_lock);
|
|
static DEFINE_MUTEX(dmc620_pmu_node_lock);
|
|
static LIST_HEAD(dmc620_pmu_irqs);
|
|
|
|
struct dmc620_pmu_irq {
|
|
struct hlist_node node;
|
|
struct list_head pmus_node;
|
|
struct list_head irqs_node;
|
|
refcount_t refcount;
|
|
unsigned int irq_num;
|
|
unsigned int cpu;
|
|
};
|
|
|
|
struct dmc620_pmu {
|
|
struct pmu pmu;
|
|
|
|
void __iomem *base;
|
|
struct dmc620_pmu_irq *irq;
|
|
struct list_head pmus_node;
|
|
|
|
/*
|
|
* We put all clkdiv2 and clk counters to a same array.
|
|
* The first DMC620_PMU_CLKDIV2_MAX_COUNTERS bits belong to
|
|
* clkdiv2 counters, the last DMC620_PMU_CLK_MAX_COUNTERS
|
|
* belong to clk counters.
|
|
*/
|
|
DECLARE_BITMAP(used_mask, DMC620_PMU_MAX_COUNTERS);
|
|
struct perf_event *events[DMC620_PMU_MAX_COUNTERS];
|
|
};
|
|
|
|
#define to_dmc620_pmu(p) (container_of(p, struct dmc620_pmu, pmu))
|
|
|
|
static int cpuhp_state_num;
|
|
|
|
struct dmc620_pmu_event_attr {
|
|
struct device_attribute attr;
|
|
u8 clkdiv2;
|
|
u8 eventid;
|
|
};
|
|
|
|
static ssize_t
|
|
dmc620_pmu_event_show(struct device *dev,
|
|
struct device_attribute *attr, char *page)
|
|
{
|
|
struct dmc620_pmu_event_attr *eattr;
|
|
|
|
eattr = container_of(attr, typeof(*eattr), attr);
|
|
|
|
return sysfs_emit(page, "event=0x%x,clkdiv2=0x%x\n", eattr->eventid, eattr->clkdiv2);
|
|
}
|
|
|
|
#define DMC620_PMU_EVENT_ATTR(_name, _eventid, _clkdiv2) \
|
|
(&((struct dmc620_pmu_event_attr[]) {{ \
|
|
.attr = __ATTR(_name, 0444, dmc620_pmu_event_show, NULL), \
|
|
.clkdiv2 = _clkdiv2, \
|
|
.eventid = _eventid, \
|
|
}})[0].attr.attr)
|
|
|
|
static struct attribute *dmc620_pmu_events_attrs[] = {
|
|
/* clkdiv2 events list */
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_cycle_count, 0x0, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_allocate, 0x1, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_queue_depth, 0x2, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_waiting_for_wr_data, 0x3, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_read_backlog, 0x4, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_waiting_for_mi, 0x5, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_hazard_resolution, 0x6, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_enqueue, 0x7, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_arbitrate, 0x8, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_lrank_turnaround_activate, 0x9, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_prank_turnaround_activate, 0xa, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_read_depth, 0xb, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_write_depth, 0xc, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_highigh_qos_depth, 0xd, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_high_qos_depth, 0xe, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_medium_qos_depth, 0xf, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_low_qos_depth, 0x10, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_activate, 0x11, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_rdwr, 0x12, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_refresh, 0x13, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_training_request, 0x14, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_t_mac_tracker, 0x15, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_bk_fsm_tracker, 0x16, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_bk_open_tracker, 0x17, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_ranks_in_pwr_down, 0x18, 1),
|
|
DMC620_PMU_EVENT_ATTR(clkdiv2_ranks_in_sref, 0x19, 1),
|
|
|
|
/* clk events list */
|
|
DMC620_PMU_EVENT_ATTR(clk_cycle_count, 0x0, 0),
|
|
DMC620_PMU_EVENT_ATTR(clk_request, 0x1, 0),
|
|
DMC620_PMU_EVENT_ATTR(clk_upload_stall, 0x2, 0),
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group dmc620_pmu_events_attr_group = {
|
|
.name = "events",
|
|
.attrs = dmc620_pmu_events_attrs,
|
|
};
|
|
|
|
/* User ABI */
|
|
#define ATTR_CFG_FLD_mask_CFG config
|
|
#define ATTR_CFG_FLD_mask_LO 0
|
|
#define ATTR_CFG_FLD_mask_HI 44
|
|
#define ATTR_CFG_FLD_match_CFG config1
|
|
#define ATTR_CFG_FLD_match_LO 0
|
|
#define ATTR_CFG_FLD_match_HI 44
|
|
#define ATTR_CFG_FLD_invert_CFG config2
|
|
#define ATTR_CFG_FLD_invert_LO 0
|
|
#define ATTR_CFG_FLD_invert_HI 0
|
|
#define ATTR_CFG_FLD_incr_CFG config2
|
|
#define ATTR_CFG_FLD_incr_LO 1
|
|
#define ATTR_CFG_FLD_incr_HI 2
|
|
#define ATTR_CFG_FLD_event_CFG config2
|
|
#define ATTR_CFG_FLD_event_LO 3
|
|
#define ATTR_CFG_FLD_event_HI 8
|
|
#define ATTR_CFG_FLD_clkdiv2_CFG config2
|
|
#define ATTR_CFG_FLD_clkdiv2_LO 9
|
|
#define ATTR_CFG_FLD_clkdiv2_HI 9
|
|
|
|
#define __GEN_PMU_FORMAT_ATTR(cfg, lo, hi) \
|
|
(lo) == (hi) ? #cfg ":" #lo "\n" : #cfg ":" #lo "-" #hi
|
|
|
|
#define _GEN_PMU_FORMAT_ATTR(cfg, lo, hi) \
|
|
__GEN_PMU_FORMAT_ATTR(cfg, lo, hi)
|
|
|
|
#define GEN_PMU_FORMAT_ATTR(name) \
|
|
PMU_FORMAT_ATTR(name, \
|
|
_GEN_PMU_FORMAT_ATTR(ATTR_CFG_FLD_##name##_CFG, \
|
|
ATTR_CFG_FLD_##name##_LO, \
|
|
ATTR_CFG_FLD_##name##_HI))
|
|
|
|
#define _ATTR_CFG_GET_FLD(attr, cfg, lo, hi) \
|
|
((((attr)->cfg) >> lo) & GENMASK_ULL(hi - lo, 0))
|
|
|
|
#define ATTR_CFG_GET_FLD(attr, name) \
|
|
_ATTR_CFG_GET_FLD(attr, \
|
|
ATTR_CFG_FLD_##name##_CFG, \
|
|
ATTR_CFG_FLD_##name##_LO, \
|
|
ATTR_CFG_FLD_##name##_HI)
|
|
|
|
GEN_PMU_FORMAT_ATTR(mask);
|
|
GEN_PMU_FORMAT_ATTR(match);
|
|
GEN_PMU_FORMAT_ATTR(invert);
|
|
GEN_PMU_FORMAT_ATTR(incr);
|
|
GEN_PMU_FORMAT_ATTR(event);
|
|
GEN_PMU_FORMAT_ATTR(clkdiv2);
|
|
|
|
static struct attribute *dmc620_pmu_formats_attrs[] = {
|
|
&format_attr_mask.attr,
|
|
&format_attr_match.attr,
|
|
&format_attr_invert.attr,
|
|
&format_attr_incr.attr,
|
|
&format_attr_event.attr,
|
|
&format_attr_clkdiv2.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group dmc620_pmu_format_attr_group = {
|
|
.name = "format",
|
|
.attrs = dmc620_pmu_formats_attrs,
|
|
};
|
|
|
|
static ssize_t dmc620_pmu_cpumask_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(dev_get_drvdata(dev));
|
|
|
|
return cpumap_print_to_pagebuf(true, buf,
|
|
cpumask_of(dmc620_pmu->irq->cpu));
|
|
}
|
|
|
|
static struct device_attribute dmc620_pmu_cpumask_attr =
|
|
__ATTR(cpumask, 0444, dmc620_pmu_cpumask_show, NULL);
|
|
|
|
static struct attribute *dmc620_pmu_cpumask_attrs[] = {
|
|
&dmc620_pmu_cpumask_attr.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group dmc620_pmu_cpumask_attr_group = {
|
|
.attrs = dmc620_pmu_cpumask_attrs,
|
|
};
|
|
|
|
static const struct attribute_group *dmc620_pmu_attr_groups[] = {
|
|
&dmc620_pmu_events_attr_group,
|
|
&dmc620_pmu_format_attr_group,
|
|
&dmc620_pmu_cpumask_attr_group,
|
|
NULL,
|
|
};
|
|
|
|
static inline
|
|
u32 dmc620_pmu_creg_read(struct dmc620_pmu *dmc620_pmu,
|
|
unsigned int idx, unsigned int reg)
|
|
{
|
|
return readl(dmc620_pmu->base + DMC620_PMU_COUNTERn_OFFSET(idx) + reg);
|
|
}
|
|
|
|
static inline
|
|
void dmc620_pmu_creg_write(struct dmc620_pmu *dmc620_pmu,
|
|
unsigned int idx, unsigned int reg, u32 val)
|
|
{
|
|
writel(val, dmc620_pmu->base + DMC620_PMU_COUNTERn_OFFSET(idx) + reg);
|
|
}
|
|
|
|
static
|
|
unsigned int dmc620_event_to_counter_control(struct perf_event *event)
|
|
{
|
|
struct perf_event_attr *attr = &event->attr;
|
|
unsigned int reg = 0;
|
|
|
|
reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_INVERT,
|
|
ATTR_CFG_GET_FLD(attr, invert));
|
|
reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_EVENT_MUX,
|
|
ATTR_CFG_GET_FLD(attr, event));
|
|
reg |= FIELD_PREP(DMC620_PMU_COUNTERn_CONTROL_INCR_MUX,
|
|
ATTR_CFG_GET_FLD(attr, incr));
|
|
|
|
return reg;
|
|
}
|
|
|
|
static int dmc620_get_event_idx(struct perf_event *event)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
int idx, start_idx, end_idx;
|
|
|
|
if (ATTR_CFG_GET_FLD(&event->attr, clkdiv2)) {
|
|
start_idx = 0;
|
|
end_idx = DMC620_PMU_CLKDIV2_MAX_COUNTERS;
|
|
} else {
|
|
start_idx = DMC620_PMU_CLKDIV2_MAX_COUNTERS;
|
|
end_idx = DMC620_PMU_MAX_COUNTERS;
|
|
}
|
|
|
|
for (idx = start_idx; idx < end_idx; ++idx) {
|
|
if (!test_and_set_bit(idx, dmc620_pmu->used_mask))
|
|
return idx;
|
|
}
|
|
|
|
/* The counters are all in use. */
|
|
return -EAGAIN;
|
|
}
|
|
|
|
static inline
|
|
u64 dmc620_pmu_read_counter(struct perf_event *event)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
|
|
return dmc620_pmu_creg_read(dmc620_pmu,
|
|
event->hw.idx, DMC620_PMU_COUNTERn_VALUE);
|
|
}
|
|
|
|
static void dmc620_pmu_event_update(struct perf_event *event)
|
|
{
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
u64 delta, prev_count, new_count;
|
|
|
|
do {
|
|
/* We may also be called from the irq handler */
|
|
prev_count = local64_read(&hwc->prev_count);
|
|
new_count = dmc620_pmu_read_counter(event);
|
|
} while (local64_cmpxchg(&hwc->prev_count,
|
|
prev_count, new_count) != prev_count);
|
|
delta = (new_count - prev_count) & DMC620_CNT_MAX_PERIOD;
|
|
local64_add(delta, &event->count);
|
|
}
|
|
|
|
static void dmc620_pmu_event_set_period(struct perf_event *event)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
|
|
local64_set(&event->hw.prev_count, DMC620_CNT_INIT);
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
event->hw.idx, DMC620_PMU_COUNTERn_VALUE, DMC620_CNT_INIT);
|
|
}
|
|
|
|
static void dmc620_pmu_enable_counter(struct perf_event *event)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
u32 reg;
|
|
|
|
reg = dmc620_event_to_counter_control(event) | DMC620_PMU_COUNTERn_CONTROL_ENABLE;
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
event->hw.idx, DMC620_PMU_COUNTERn_CONTROL, reg);
|
|
}
|
|
|
|
static void dmc620_pmu_disable_counter(struct perf_event *event)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
event->hw.idx, DMC620_PMU_COUNTERn_CONTROL, 0);
|
|
}
|
|
|
|
static irqreturn_t dmc620_pmu_handle_irq(int irq_num, void *data)
|
|
{
|
|
struct dmc620_pmu_irq *irq = data;
|
|
struct dmc620_pmu *dmc620_pmu;
|
|
irqreturn_t ret = IRQ_NONE;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(dmc620_pmu, &irq->pmus_node, pmus_node) {
|
|
unsigned long status;
|
|
struct perf_event *event;
|
|
unsigned int idx;
|
|
|
|
/*
|
|
* HW doesn't provide a control to atomically disable all counters.
|
|
* To prevent race condition (overflow happens while clearing status register),
|
|
* disable all events before continuing
|
|
*/
|
|
for (idx = 0; idx < DMC620_PMU_MAX_COUNTERS; idx++) {
|
|
event = dmc620_pmu->events[idx];
|
|
if (!event)
|
|
continue;
|
|
dmc620_pmu_disable_counter(event);
|
|
}
|
|
|
|
status = readl(dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2);
|
|
status |= (readl(dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK) <<
|
|
DMC620_PMU_CLKDIV2_MAX_COUNTERS);
|
|
if (status) {
|
|
for_each_set_bit(idx, &status,
|
|
DMC620_PMU_MAX_COUNTERS) {
|
|
event = dmc620_pmu->events[idx];
|
|
if (WARN_ON_ONCE(!event))
|
|
continue;
|
|
dmc620_pmu_event_update(event);
|
|
dmc620_pmu_event_set_period(event);
|
|
}
|
|
|
|
if (status & DMC620_PMU_OVERFLOW_STATUS_CLKDIV2_MASK)
|
|
writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2);
|
|
|
|
if ((status >> DMC620_PMU_CLKDIV2_MAX_COUNTERS) &
|
|
DMC620_PMU_OVERFLOW_STATUS_CLK_MASK)
|
|
writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK);
|
|
}
|
|
|
|
for (idx = 0; idx < DMC620_PMU_MAX_COUNTERS; idx++) {
|
|
event = dmc620_pmu->events[idx];
|
|
if (!event)
|
|
continue;
|
|
if (!(event->hw.state & PERF_HES_STOPPED))
|
|
dmc620_pmu_enable_counter(event);
|
|
}
|
|
|
|
ret = IRQ_HANDLED;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct dmc620_pmu_irq *__dmc620_pmu_get_irq(int irq_num)
|
|
{
|
|
struct dmc620_pmu_irq *irq;
|
|
int ret;
|
|
|
|
list_for_each_entry(irq, &dmc620_pmu_irqs, irqs_node)
|
|
if (irq->irq_num == irq_num && refcount_inc_not_zero(&irq->refcount))
|
|
return irq;
|
|
|
|
irq = kzalloc(sizeof(*irq), GFP_KERNEL);
|
|
if (!irq)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
INIT_LIST_HEAD(&irq->pmus_node);
|
|
|
|
/* Pick one CPU to be the preferred one to use */
|
|
irq->cpu = raw_smp_processor_id();
|
|
refcount_set(&irq->refcount, 1);
|
|
|
|
ret = request_irq(irq_num, dmc620_pmu_handle_irq,
|
|
IRQF_NOBALANCING | IRQF_NO_THREAD,
|
|
"dmc620-pmu", irq);
|
|
if (ret)
|
|
goto out_free_aff;
|
|
|
|
ret = irq_set_affinity(irq_num, cpumask_of(irq->cpu));
|
|
if (ret)
|
|
goto out_free_irq;
|
|
|
|
ret = cpuhp_state_add_instance_nocalls(cpuhp_state_num, &irq->node);
|
|
if (ret)
|
|
goto out_free_irq;
|
|
|
|
irq->irq_num = irq_num;
|
|
list_add(&irq->irqs_node, &dmc620_pmu_irqs);
|
|
|
|
return irq;
|
|
|
|
out_free_irq:
|
|
free_irq(irq_num, irq);
|
|
out_free_aff:
|
|
kfree(irq);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
static int dmc620_pmu_get_irq(struct dmc620_pmu *dmc620_pmu, int irq_num)
|
|
{
|
|
struct dmc620_pmu_irq *irq;
|
|
|
|
mutex_lock(&dmc620_pmu_irqs_lock);
|
|
irq = __dmc620_pmu_get_irq(irq_num);
|
|
mutex_unlock(&dmc620_pmu_irqs_lock);
|
|
|
|
if (IS_ERR(irq))
|
|
return PTR_ERR(irq);
|
|
|
|
dmc620_pmu->irq = irq;
|
|
mutex_lock(&dmc620_pmu_node_lock);
|
|
list_add_rcu(&dmc620_pmu->pmus_node, &irq->pmus_node);
|
|
mutex_unlock(&dmc620_pmu_node_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void dmc620_pmu_put_irq(struct dmc620_pmu *dmc620_pmu)
|
|
{
|
|
struct dmc620_pmu_irq *irq = dmc620_pmu->irq;
|
|
|
|
mutex_lock(&dmc620_pmu_node_lock);
|
|
list_del_rcu(&dmc620_pmu->pmus_node);
|
|
mutex_unlock(&dmc620_pmu_node_lock);
|
|
|
|
mutex_lock(&dmc620_pmu_irqs_lock);
|
|
if (!refcount_dec_and_test(&irq->refcount)) {
|
|
mutex_unlock(&dmc620_pmu_irqs_lock);
|
|
return;
|
|
}
|
|
|
|
list_del(&irq->irqs_node);
|
|
mutex_unlock(&dmc620_pmu_irqs_lock);
|
|
|
|
free_irq(irq->irq_num, irq);
|
|
cpuhp_state_remove_instance_nocalls(cpuhp_state_num, &irq->node);
|
|
kfree(irq);
|
|
}
|
|
|
|
static int dmc620_pmu_event_init(struct perf_event *event)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
struct perf_event *sibling;
|
|
|
|
if (event->attr.type != event->pmu->type)
|
|
return -ENOENT;
|
|
|
|
/*
|
|
* DMC 620 PMUs are shared across all cpus and cannot
|
|
* support task bound and sampling events.
|
|
*/
|
|
if (is_sampling_event(event) ||
|
|
event->attach_state & PERF_ATTACH_TASK) {
|
|
dev_dbg(dmc620_pmu->pmu.dev,
|
|
"Can't support per-task counters\n");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
/*
|
|
* 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, where each
|
|
* event could be theoretically assigned to a different CPU. To
|
|
* mitigate this, we enforce CPU assignment to one, selected
|
|
* processor.
|
|
*/
|
|
event->cpu = dmc620_pmu->irq->cpu;
|
|
if (event->cpu < 0)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* We can't atomically disable all HW counters so only one event allowed,
|
|
* although software events are acceptable.
|
|
*/
|
|
if (event->group_leader != event &&
|
|
!is_software_event(event->group_leader))
|
|
return -EINVAL;
|
|
|
|
for_each_sibling_event(sibling, event->group_leader) {
|
|
if (sibling != event &&
|
|
!is_software_event(sibling))
|
|
return -EINVAL;
|
|
}
|
|
|
|
hwc->idx = -1;
|
|
return 0;
|
|
}
|
|
|
|
static void dmc620_pmu_read(struct perf_event *event)
|
|
{
|
|
dmc620_pmu_event_update(event);
|
|
}
|
|
|
|
static void dmc620_pmu_start(struct perf_event *event, int flags)
|
|
{
|
|
event->hw.state = 0;
|
|
dmc620_pmu_event_set_period(event);
|
|
dmc620_pmu_enable_counter(event);
|
|
}
|
|
|
|
static void dmc620_pmu_stop(struct perf_event *event, int flags)
|
|
{
|
|
if (event->hw.state & PERF_HES_STOPPED)
|
|
return;
|
|
|
|
dmc620_pmu_disable_counter(event);
|
|
dmc620_pmu_event_update(event);
|
|
event->hw.state |= PERF_HES_STOPPED | PERF_HES_UPTODATE;
|
|
}
|
|
|
|
static int dmc620_pmu_add(struct perf_event *event, int flags)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
struct perf_event_attr *attr = &event->attr;
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
int idx;
|
|
u64 reg;
|
|
|
|
idx = dmc620_get_event_idx(event);
|
|
if (idx < 0)
|
|
return idx;
|
|
|
|
hwc->idx = idx;
|
|
dmc620_pmu->events[idx] = event;
|
|
hwc->state = PERF_HES_STOPPED | PERF_HES_UPTODATE;
|
|
|
|
reg = ATTR_CFG_GET_FLD(attr, mask);
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
idx, DMC620_PMU_COUNTERn_MASK_31_00, lower_32_bits(reg));
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
idx, DMC620_PMU_COUNTERn_MASK_63_32, upper_32_bits(reg));
|
|
|
|
reg = ATTR_CFG_GET_FLD(attr, match);
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
idx, DMC620_PMU_COUNTERn_MATCH_31_00, lower_32_bits(reg));
|
|
dmc620_pmu_creg_write(dmc620_pmu,
|
|
idx, DMC620_PMU_COUNTERn_MATCH_63_32, upper_32_bits(reg));
|
|
|
|
if (flags & PERF_EF_START)
|
|
dmc620_pmu_start(event, PERF_EF_RELOAD);
|
|
|
|
perf_event_update_userpage(event);
|
|
return 0;
|
|
}
|
|
|
|
static void dmc620_pmu_del(struct perf_event *event, int flags)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = to_dmc620_pmu(event->pmu);
|
|
struct hw_perf_event *hwc = &event->hw;
|
|
int idx = hwc->idx;
|
|
|
|
dmc620_pmu_stop(event, PERF_EF_UPDATE);
|
|
dmc620_pmu->events[idx] = NULL;
|
|
clear_bit(idx, dmc620_pmu->used_mask);
|
|
perf_event_update_userpage(event);
|
|
}
|
|
|
|
static int dmc620_pmu_cpu_teardown(unsigned int cpu,
|
|
struct hlist_node *node)
|
|
{
|
|
struct dmc620_pmu_irq *irq;
|
|
struct dmc620_pmu *dmc620_pmu;
|
|
unsigned int target;
|
|
|
|
irq = hlist_entry_safe(node, struct dmc620_pmu_irq, node);
|
|
if (cpu != irq->cpu)
|
|
return 0;
|
|
|
|
target = cpumask_any_but(cpu_online_mask, cpu);
|
|
if (target >= nr_cpu_ids)
|
|
return 0;
|
|
|
|
/* We're only reading, but this isn't the place to be involving RCU */
|
|
mutex_lock(&dmc620_pmu_node_lock);
|
|
list_for_each_entry(dmc620_pmu, &irq->pmus_node, pmus_node)
|
|
perf_pmu_migrate_context(&dmc620_pmu->pmu, irq->cpu, target);
|
|
mutex_unlock(&dmc620_pmu_node_lock);
|
|
|
|
WARN_ON(irq_set_affinity(irq->irq_num, cpumask_of(target)));
|
|
irq->cpu = target;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dmc620_pmu_device_probe(struct platform_device *pdev)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu;
|
|
struct resource *res;
|
|
char *name;
|
|
int irq_num;
|
|
int i, ret;
|
|
|
|
dmc620_pmu = devm_kzalloc(&pdev->dev,
|
|
sizeof(struct dmc620_pmu), GFP_KERNEL);
|
|
if (!dmc620_pmu)
|
|
return -ENOMEM;
|
|
|
|
platform_set_drvdata(pdev, dmc620_pmu);
|
|
|
|
dmc620_pmu->pmu = (struct pmu) {
|
|
.module = THIS_MODULE,
|
|
.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
|
|
.task_ctx_nr = perf_invalid_context,
|
|
.event_init = dmc620_pmu_event_init,
|
|
.add = dmc620_pmu_add,
|
|
.del = dmc620_pmu_del,
|
|
.start = dmc620_pmu_start,
|
|
.stop = dmc620_pmu_stop,
|
|
.read = dmc620_pmu_read,
|
|
.attr_groups = dmc620_pmu_attr_groups,
|
|
};
|
|
|
|
dmc620_pmu->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
|
|
if (IS_ERR(dmc620_pmu->base))
|
|
return PTR_ERR(dmc620_pmu->base);
|
|
|
|
/* Make sure device is reset before enabling interrupt */
|
|
for (i = 0; i < DMC620_PMU_MAX_COUNTERS; i++)
|
|
dmc620_pmu_creg_write(dmc620_pmu, i, DMC620_PMU_COUNTERn_CONTROL, 0);
|
|
writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLKDIV2);
|
|
writel(0, dmc620_pmu->base + DMC620_PMU_OVERFLOW_STATUS_CLK);
|
|
|
|
irq_num = platform_get_irq(pdev, 0);
|
|
if (irq_num < 0)
|
|
return irq_num;
|
|
|
|
ret = dmc620_pmu_get_irq(dmc620_pmu, irq_num);
|
|
if (ret)
|
|
return ret;
|
|
|
|
name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
|
|
"%s_%llx", DMC620_PMUNAME,
|
|
(u64)(res->start >> DMC620_PA_SHIFT));
|
|
if (!name) {
|
|
dev_err(&pdev->dev,
|
|
"Create name failed, PMU @%pa\n", &res->start);
|
|
ret = -ENOMEM;
|
|
goto out_teardown_dev;
|
|
}
|
|
|
|
ret = perf_pmu_register(&dmc620_pmu->pmu, name, -1);
|
|
if (ret)
|
|
goto out_teardown_dev;
|
|
|
|
return 0;
|
|
|
|
out_teardown_dev:
|
|
dmc620_pmu_put_irq(dmc620_pmu);
|
|
synchronize_rcu();
|
|
return ret;
|
|
}
|
|
|
|
static int dmc620_pmu_device_remove(struct platform_device *pdev)
|
|
{
|
|
struct dmc620_pmu *dmc620_pmu = platform_get_drvdata(pdev);
|
|
|
|
dmc620_pmu_put_irq(dmc620_pmu);
|
|
|
|
/* perf will synchronise RCU before devres can free dmc620_pmu */
|
|
perf_pmu_unregister(&dmc620_pmu->pmu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct acpi_device_id dmc620_acpi_match[] = {
|
|
{ "ARMHD620", 0},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(acpi, dmc620_acpi_match);
|
|
static struct platform_driver dmc620_pmu_driver = {
|
|
.driver = {
|
|
.name = DMC620_DRVNAME,
|
|
.acpi_match_table = dmc620_acpi_match,
|
|
.suppress_bind_attrs = true,
|
|
},
|
|
.probe = dmc620_pmu_device_probe,
|
|
.remove = dmc620_pmu_device_remove,
|
|
};
|
|
|
|
static int __init dmc620_pmu_init(void)
|
|
{
|
|
int ret;
|
|
|
|
cpuhp_state_num = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
|
|
DMC620_DRVNAME,
|
|
NULL,
|
|
dmc620_pmu_cpu_teardown);
|
|
if (cpuhp_state_num < 0)
|
|
return cpuhp_state_num;
|
|
|
|
ret = platform_driver_register(&dmc620_pmu_driver);
|
|
if (ret)
|
|
cpuhp_remove_multi_state(cpuhp_state_num);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit dmc620_pmu_exit(void)
|
|
{
|
|
platform_driver_unregister(&dmc620_pmu_driver);
|
|
cpuhp_remove_multi_state(cpuhp_state_num);
|
|
}
|
|
|
|
module_init(dmc620_pmu_init);
|
|
module_exit(dmc620_pmu_exit);
|
|
|
|
MODULE_DESCRIPTION("Perf driver for the ARM DMC-620 memory controller");
|
|
MODULE_AUTHOR("Tuan Phan <tuanphan@os.amperecomputing.com");
|
|
MODULE_LICENSE("GPL v2");
|