linux/drivers/perf/arm_spe_pmu.c
Rob Herring 918dc87b74 drivers/perf: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174832.4061752-1-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2023-07-27 13:02:23 +01:00

1339 lines
35 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Perf support for the Statistical Profiling Extension, introduced as
* part of ARMv8.2.
*
* Copyright (C) 2016 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#define PMUNAME "arm_spe"
#define DRVNAME PMUNAME "_pmu"
#define pr_fmt(fmt) DRVNAME ": " fmt
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/capability.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/of.h>
#include <linux/perf_event.h>
#include <linux/perf/arm_pmu.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/vmalloc.h>
#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/mmu.h>
#include <asm/sysreg.h>
/*
* Cache if the event is allowed to trace Context information.
* This allows us to perform the check, i.e, perfmon_capable(),
* in the context of the event owner, once, during the event_init().
*/
#define SPE_PMU_HW_FLAGS_CX 0x00001
static_assert((PERF_EVENT_FLAG_ARCH & SPE_PMU_HW_FLAGS_CX) == SPE_PMU_HW_FLAGS_CX);
static void set_spe_event_has_cx(struct perf_event *event)
{
if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && perfmon_capable())
event->hw.flags |= SPE_PMU_HW_FLAGS_CX;
}
static bool get_spe_event_has_cx(struct perf_event *event)
{
return !!(event->hw.flags & SPE_PMU_HW_FLAGS_CX);
}
#define ARM_SPE_BUF_PAD_BYTE 0
struct arm_spe_pmu_buf {
int nr_pages;
bool snapshot;
void *base;
};
struct arm_spe_pmu {
struct pmu pmu;
struct platform_device *pdev;
cpumask_t supported_cpus;
struct hlist_node hotplug_node;
int irq; /* PPI */
u16 pmsver;
u16 min_period;
u16 counter_sz;
#define SPE_PMU_FEAT_FILT_EVT (1UL << 0)
#define SPE_PMU_FEAT_FILT_TYP (1UL << 1)
#define SPE_PMU_FEAT_FILT_LAT (1UL << 2)
#define SPE_PMU_FEAT_ARCH_INST (1UL << 3)
#define SPE_PMU_FEAT_LDS (1UL << 4)
#define SPE_PMU_FEAT_ERND (1UL << 5)
#define SPE_PMU_FEAT_INV_FILT_EVT (1UL << 6)
#define SPE_PMU_FEAT_DEV_PROBED (1UL << 63)
u64 features;
u16 max_record_sz;
u16 align;
struct perf_output_handle __percpu *handle;
};
#define to_spe_pmu(p) (container_of(p, struct arm_spe_pmu, pmu))
/* Convert a free-running index from perf into an SPE buffer offset */
#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
/* Keep track of our dynamic hotplug state */
static enum cpuhp_state arm_spe_pmu_online;
enum arm_spe_pmu_buf_fault_action {
SPE_PMU_BUF_FAULT_ACT_SPURIOUS,
SPE_PMU_BUF_FAULT_ACT_FATAL,
SPE_PMU_BUF_FAULT_ACT_OK,
};
/* This sysfs gunk was really good fun to write. */
enum arm_spe_pmu_capabilities {
SPE_PMU_CAP_ARCH_INST = 0,
SPE_PMU_CAP_ERND,
SPE_PMU_CAP_FEAT_MAX,
SPE_PMU_CAP_CNT_SZ = SPE_PMU_CAP_FEAT_MAX,
SPE_PMU_CAP_MIN_IVAL,
};
static int arm_spe_pmu_feat_caps[SPE_PMU_CAP_FEAT_MAX] = {
[SPE_PMU_CAP_ARCH_INST] = SPE_PMU_FEAT_ARCH_INST,
[SPE_PMU_CAP_ERND] = SPE_PMU_FEAT_ERND,
};
static u32 arm_spe_pmu_cap_get(struct arm_spe_pmu *spe_pmu, int cap)
{
if (cap < SPE_PMU_CAP_FEAT_MAX)
return !!(spe_pmu->features & arm_spe_pmu_feat_caps[cap]);
switch (cap) {
case SPE_PMU_CAP_CNT_SZ:
return spe_pmu->counter_sz;
case SPE_PMU_CAP_MIN_IVAL:
return spe_pmu->min_period;
default:
WARN(1, "unknown cap %d\n", cap);
}
return 0;
}
static ssize_t arm_spe_pmu_cap_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
struct dev_ext_attribute *ea =
container_of(attr, struct dev_ext_attribute, attr);
int cap = (long)ea->var;
return sysfs_emit(buf, "%u\n", arm_spe_pmu_cap_get(spe_pmu, cap));
}
#define SPE_EXT_ATTR_ENTRY(_name, _func, _var) \
&((struct dev_ext_attribute[]) { \
{ __ATTR(_name, S_IRUGO, _func, NULL), (void *)_var } \
})[0].attr.attr
#define SPE_CAP_EXT_ATTR_ENTRY(_name, _var) \
SPE_EXT_ATTR_ENTRY(_name, arm_spe_pmu_cap_show, _var)
static struct attribute *arm_spe_pmu_cap_attr[] = {
SPE_CAP_EXT_ATTR_ENTRY(arch_inst, SPE_PMU_CAP_ARCH_INST),
SPE_CAP_EXT_ATTR_ENTRY(ernd, SPE_PMU_CAP_ERND),
SPE_CAP_EXT_ATTR_ENTRY(count_size, SPE_PMU_CAP_CNT_SZ),
SPE_CAP_EXT_ATTR_ENTRY(min_interval, SPE_PMU_CAP_MIN_IVAL),
NULL,
};
static const struct attribute_group arm_spe_pmu_cap_group = {
.name = "caps",
.attrs = arm_spe_pmu_cap_attr,
};
/* User ABI */
#define ATTR_CFG_FLD_ts_enable_CFG config /* PMSCR_EL1.TS */
#define ATTR_CFG_FLD_ts_enable_LO 0
#define ATTR_CFG_FLD_ts_enable_HI 0
#define ATTR_CFG_FLD_pa_enable_CFG config /* PMSCR_EL1.PA */
#define ATTR_CFG_FLD_pa_enable_LO 1
#define ATTR_CFG_FLD_pa_enable_HI 1
#define ATTR_CFG_FLD_pct_enable_CFG config /* PMSCR_EL1.PCT */
#define ATTR_CFG_FLD_pct_enable_LO 2
#define ATTR_CFG_FLD_pct_enable_HI 2
#define ATTR_CFG_FLD_jitter_CFG config /* PMSIRR_EL1.RND */
#define ATTR_CFG_FLD_jitter_LO 16
#define ATTR_CFG_FLD_jitter_HI 16
#define ATTR_CFG_FLD_branch_filter_CFG config /* PMSFCR_EL1.B */
#define ATTR_CFG_FLD_branch_filter_LO 32
#define ATTR_CFG_FLD_branch_filter_HI 32
#define ATTR_CFG_FLD_load_filter_CFG config /* PMSFCR_EL1.LD */
#define ATTR_CFG_FLD_load_filter_LO 33
#define ATTR_CFG_FLD_load_filter_HI 33
#define ATTR_CFG_FLD_store_filter_CFG config /* PMSFCR_EL1.ST */
#define ATTR_CFG_FLD_store_filter_LO 34
#define ATTR_CFG_FLD_store_filter_HI 34
#define ATTR_CFG_FLD_event_filter_CFG config1 /* PMSEVFR_EL1 */
#define ATTR_CFG_FLD_event_filter_LO 0
#define ATTR_CFG_FLD_event_filter_HI 63
#define ATTR_CFG_FLD_min_latency_CFG config2 /* PMSLATFR_EL1.MINLAT */
#define ATTR_CFG_FLD_min_latency_LO 0
#define ATTR_CFG_FLD_min_latency_HI 11
#define ATTR_CFG_FLD_inv_event_filter_CFG config3 /* PMSNEVFR_EL1 */
#define ATTR_CFG_FLD_inv_event_filter_LO 0
#define ATTR_CFG_FLD_inv_event_filter_HI 63
/* Why does everything I do descend into this? */
#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(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(ts_enable);
GEN_PMU_FORMAT_ATTR(pa_enable);
GEN_PMU_FORMAT_ATTR(pct_enable);
GEN_PMU_FORMAT_ATTR(jitter);
GEN_PMU_FORMAT_ATTR(branch_filter);
GEN_PMU_FORMAT_ATTR(load_filter);
GEN_PMU_FORMAT_ATTR(store_filter);
GEN_PMU_FORMAT_ATTR(event_filter);
GEN_PMU_FORMAT_ATTR(inv_event_filter);
GEN_PMU_FORMAT_ATTR(min_latency);
static struct attribute *arm_spe_pmu_formats_attr[] = {
&format_attr_ts_enable.attr,
&format_attr_pa_enable.attr,
&format_attr_pct_enable.attr,
&format_attr_jitter.attr,
&format_attr_branch_filter.attr,
&format_attr_load_filter.attr,
&format_attr_store_filter.attr,
&format_attr_event_filter.attr,
&format_attr_inv_event_filter.attr,
&format_attr_min_latency.attr,
NULL,
};
static umode_t arm_spe_pmu_format_attr_is_visible(struct kobject *kobj,
struct attribute *attr,
int unused)
{
struct device *dev = kobj_to_dev(kobj);
struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
if (attr == &format_attr_inv_event_filter.attr && !(spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT))
return 0;
return attr->mode;
}
static const struct attribute_group arm_spe_pmu_format_group = {
.name = "format",
.is_visible = arm_spe_pmu_format_attr_is_visible,
.attrs = arm_spe_pmu_formats_attr,
};
static ssize_t cpumask_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct arm_spe_pmu *spe_pmu = dev_get_drvdata(dev);
return cpumap_print_to_pagebuf(true, buf, &spe_pmu->supported_cpus);
}
static DEVICE_ATTR_RO(cpumask);
static struct attribute *arm_spe_pmu_attrs[] = {
&dev_attr_cpumask.attr,
NULL,
};
static const struct attribute_group arm_spe_pmu_group = {
.attrs = arm_spe_pmu_attrs,
};
static const struct attribute_group *arm_spe_pmu_attr_groups[] = {
&arm_spe_pmu_group,
&arm_spe_pmu_cap_group,
&arm_spe_pmu_format_group,
NULL,
};
/* Convert between user ABI and register values */
static u64 arm_spe_event_to_pmscr(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
u64 reg = 0;
reg |= FIELD_PREP(PMSCR_EL1_TS, ATTR_CFG_GET_FLD(attr, ts_enable));
reg |= FIELD_PREP(PMSCR_EL1_PA, ATTR_CFG_GET_FLD(attr, pa_enable));
reg |= FIELD_PREP(PMSCR_EL1_PCT, ATTR_CFG_GET_FLD(attr, pct_enable));
if (!attr->exclude_user)
reg |= PMSCR_EL1_E0SPE;
if (!attr->exclude_kernel)
reg |= PMSCR_EL1_E1SPE;
if (get_spe_event_has_cx(event))
reg |= PMSCR_EL1_CX;
return reg;
}
static void arm_spe_event_sanitise_period(struct perf_event *event)
{
struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
u64 period = event->hw.sample_period;
u64 max_period = PMSIRR_EL1_INTERVAL_MASK;
if (period < spe_pmu->min_period)
period = spe_pmu->min_period;
else if (period > max_period)
period = max_period;
else
period &= max_period;
event->hw.sample_period = period;
}
static u64 arm_spe_event_to_pmsirr(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
u64 reg = 0;
arm_spe_event_sanitise_period(event);
reg |= FIELD_PREP(PMSIRR_EL1_RND, ATTR_CFG_GET_FLD(attr, jitter));
reg |= event->hw.sample_period;
return reg;
}
static u64 arm_spe_event_to_pmsfcr(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
u64 reg = 0;
reg |= FIELD_PREP(PMSFCR_EL1_LD, ATTR_CFG_GET_FLD(attr, load_filter));
reg |= FIELD_PREP(PMSFCR_EL1_ST, ATTR_CFG_GET_FLD(attr, store_filter));
reg |= FIELD_PREP(PMSFCR_EL1_B, ATTR_CFG_GET_FLD(attr, branch_filter));
if (reg)
reg |= PMSFCR_EL1_FT;
if (ATTR_CFG_GET_FLD(attr, event_filter))
reg |= PMSFCR_EL1_FE;
if (ATTR_CFG_GET_FLD(attr, inv_event_filter))
reg |= PMSFCR_EL1_FnE;
if (ATTR_CFG_GET_FLD(attr, min_latency))
reg |= PMSFCR_EL1_FL;
return reg;
}
static u64 arm_spe_event_to_pmsevfr(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
return ATTR_CFG_GET_FLD(attr, event_filter);
}
static u64 arm_spe_event_to_pmsnevfr(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
return ATTR_CFG_GET_FLD(attr, inv_event_filter);
}
static u64 arm_spe_event_to_pmslatfr(struct perf_event *event)
{
struct perf_event_attr *attr = &event->attr;
return FIELD_PREP(PMSLATFR_EL1_MINLAT, ATTR_CFG_GET_FLD(attr, min_latency));
}
static void arm_spe_pmu_pad_buf(struct perf_output_handle *handle, int len)
{
struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
u64 head = PERF_IDX2OFF(handle->head, buf);
memset(buf->base + head, ARM_SPE_BUF_PAD_BYTE, len);
if (!buf->snapshot)
perf_aux_output_skip(handle, len);
}
static u64 arm_spe_pmu_next_snapshot_off(struct perf_output_handle *handle)
{
struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
struct arm_spe_pmu *spe_pmu = to_spe_pmu(handle->event->pmu);
u64 head = PERF_IDX2OFF(handle->head, buf);
u64 limit = buf->nr_pages * PAGE_SIZE;
/*
* The trace format isn't parseable in reverse, so clamp
* the limit to half of the buffer size in snapshot mode
* so that the worst case is half a buffer of records, as
* opposed to a single record.
*/
if (head < limit >> 1)
limit >>= 1;
/*
* If we're within max_record_sz of the limit, we must
* pad, move the head index and recompute the limit.
*/
if (limit - head < spe_pmu->max_record_sz) {
arm_spe_pmu_pad_buf(handle, limit - head);
handle->head = PERF_IDX2OFF(limit, buf);
limit = ((buf->nr_pages * PAGE_SIZE) >> 1) + handle->head;
}
return limit;
}
static u64 __arm_spe_pmu_next_off(struct perf_output_handle *handle)
{
struct arm_spe_pmu *spe_pmu = to_spe_pmu(handle->event->pmu);
struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
const u64 bufsize = buf->nr_pages * PAGE_SIZE;
u64 limit = bufsize;
u64 head, tail, wakeup;
/*
* The head can be misaligned for two reasons:
*
* 1. The hardware left PMBPTR pointing to the first byte after
* a record when generating a buffer management event.
*
* 2. We used perf_aux_output_skip to consume handle->size bytes
* and CIRC_SPACE was used to compute the size, which always
* leaves one entry free.
*
* Deal with this by padding to the next alignment boundary and
* moving the head index. If we run out of buffer space, we'll
* reduce handle->size to zero and end up reporting truncation.
*/
head = PERF_IDX2OFF(handle->head, buf);
if (!IS_ALIGNED(head, spe_pmu->align)) {
unsigned long delta = roundup(head, spe_pmu->align) - head;
delta = min(delta, handle->size);
arm_spe_pmu_pad_buf(handle, delta);
head = PERF_IDX2OFF(handle->head, buf);
}
/* If we've run out of free space, then nothing more to do */
if (!handle->size)
goto no_space;
/* Compute the tail and wakeup indices now that we've aligned head */
tail = PERF_IDX2OFF(handle->head + handle->size, buf);
wakeup = PERF_IDX2OFF(handle->wakeup, buf);
/*
* Avoid clobbering unconsumed data. We know we have space, so
* if we see head == tail we know that the buffer is empty. If
* head > tail, then there's nothing to clobber prior to
* wrapping.
*/
if (head < tail)
limit = round_down(tail, PAGE_SIZE);
/*
* Wakeup may be arbitrarily far into the future. If it's not in
* the current generation, either we'll wrap before hitting it,
* or it's in the past and has been handled already.
*
* If there's a wakeup before we wrap, arrange to be woken up by
* the page boundary following it. Keep the tail boundary if
* that's lower.
*/
if (handle->wakeup < (handle->head + handle->size) && head <= wakeup)
limit = min(limit, round_up(wakeup, PAGE_SIZE));
if (limit > head)
return limit;
arm_spe_pmu_pad_buf(handle, handle->size);
no_space:
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
perf_aux_output_end(handle, 0);
return 0;
}
static u64 arm_spe_pmu_next_off(struct perf_output_handle *handle)
{
struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
struct arm_spe_pmu *spe_pmu = to_spe_pmu(handle->event->pmu);
u64 limit = __arm_spe_pmu_next_off(handle);
u64 head = PERF_IDX2OFF(handle->head, buf);
/*
* If the head has come too close to the end of the buffer,
* then pad to the end and recompute the limit.
*/
if (limit && (limit - head < spe_pmu->max_record_sz)) {
arm_spe_pmu_pad_buf(handle, limit - head);
limit = __arm_spe_pmu_next_off(handle);
}
return limit;
}
static void arm_spe_perf_aux_output_begin(struct perf_output_handle *handle,
struct perf_event *event)
{
u64 base, limit;
struct arm_spe_pmu_buf *buf;
/* Start a new aux session */
buf = perf_aux_output_begin(handle, event);
if (!buf) {
event->hw.state |= PERF_HES_STOPPED;
/*
* We still need to clear the limit pointer, since the
* profiler might only be disabled by virtue of a fault.
*/
limit = 0;
goto out_write_limit;
}
limit = buf->snapshot ? arm_spe_pmu_next_snapshot_off(handle)
: arm_spe_pmu_next_off(handle);
if (limit)
limit |= PMBLIMITR_EL1_E;
limit += (u64)buf->base;
base = (u64)buf->base + PERF_IDX2OFF(handle->head, buf);
write_sysreg_s(base, SYS_PMBPTR_EL1);
out_write_limit:
write_sysreg_s(limit, SYS_PMBLIMITR_EL1);
}
static void arm_spe_perf_aux_output_end(struct perf_output_handle *handle)
{
struct arm_spe_pmu_buf *buf = perf_get_aux(handle);
u64 offset, size;
offset = read_sysreg_s(SYS_PMBPTR_EL1) - (u64)buf->base;
size = offset - PERF_IDX2OFF(handle->head, buf);
if (buf->snapshot)
handle->head = offset;
perf_aux_output_end(handle, size);
}
static void arm_spe_pmu_disable_and_drain_local(void)
{
/* Disable profiling at EL0 and EL1 */
write_sysreg_s(0, SYS_PMSCR_EL1);
isb();
/* Drain any buffered data */
psb_csync();
dsb(nsh);
/* Disable the profiling buffer */
write_sysreg_s(0, SYS_PMBLIMITR_EL1);
isb();
}
/* IRQ handling */
static enum arm_spe_pmu_buf_fault_action
arm_spe_pmu_buf_get_fault_act(struct perf_output_handle *handle)
{
const char *err_str;
u64 pmbsr;
enum arm_spe_pmu_buf_fault_action ret;
/*
* Ensure new profiling data is visible to the CPU and any external
* aborts have been resolved.
*/
psb_csync();
dsb(nsh);
/* Ensure hardware updates to PMBPTR_EL1 are visible */
isb();
/* Service required? */
pmbsr = read_sysreg_s(SYS_PMBSR_EL1);
if (!FIELD_GET(PMBSR_EL1_S, pmbsr))
return SPE_PMU_BUF_FAULT_ACT_SPURIOUS;
/*
* If we've lost data, disable profiling and also set the PARTIAL
* flag to indicate that the last record is corrupted.
*/
if (FIELD_GET(PMBSR_EL1_DL, pmbsr))
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED |
PERF_AUX_FLAG_PARTIAL);
/* Report collisions to userspace so that it can up the period */
if (FIELD_GET(PMBSR_EL1_COLL, pmbsr))
perf_aux_output_flag(handle, PERF_AUX_FLAG_COLLISION);
/* We only expect buffer management events */
switch (FIELD_GET(PMBSR_EL1_EC, pmbsr)) {
case PMBSR_EL1_EC_BUF:
/* Handled below */
break;
case PMBSR_EL1_EC_FAULT_S1:
case PMBSR_EL1_EC_FAULT_S2:
err_str = "Unexpected buffer fault";
goto out_err;
default:
err_str = "Unknown error code";
goto out_err;
}
/* Buffer management event */
switch (FIELD_GET(PMBSR_EL1_BUF_BSC_MASK, pmbsr)) {
case PMBSR_EL1_BUF_BSC_FULL:
ret = SPE_PMU_BUF_FAULT_ACT_OK;
goto out_stop;
default:
err_str = "Unknown buffer status code";
}
out_err:
pr_err_ratelimited("%s on CPU %d [PMBSR=0x%016llx, PMBPTR=0x%016llx, PMBLIMITR=0x%016llx]\n",
err_str, smp_processor_id(), pmbsr,
read_sysreg_s(SYS_PMBPTR_EL1),
read_sysreg_s(SYS_PMBLIMITR_EL1));
ret = SPE_PMU_BUF_FAULT_ACT_FATAL;
out_stop:
arm_spe_perf_aux_output_end(handle);
return ret;
}
static irqreturn_t arm_spe_pmu_irq_handler(int irq, void *dev)
{
struct perf_output_handle *handle = dev;
struct perf_event *event = handle->event;
enum arm_spe_pmu_buf_fault_action act;
if (!perf_get_aux(handle))
return IRQ_NONE;
act = arm_spe_pmu_buf_get_fault_act(handle);
if (act == SPE_PMU_BUF_FAULT_ACT_SPURIOUS)
return IRQ_NONE;
/*
* Ensure perf callbacks have completed, which may disable the
* profiling buffer in response to a TRUNCATION flag.
*/
irq_work_run();
switch (act) {
case SPE_PMU_BUF_FAULT_ACT_FATAL:
/*
* If a fatal exception occurred then leaving the profiling
* buffer enabled is a recipe waiting to happen. Since
* fatal faults don't always imply truncation, make sure
* that the profiling buffer is disabled explicitly before
* clearing the syndrome register.
*/
arm_spe_pmu_disable_and_drain_local();
break;
case SPE_PMU_BUF_FAULT_ACT_OK:
/*
* We handled the fault (the buffer was full), so resume
* profiling as long as we didn't detect truncation.
* PMBPTR might be misaligned, but we'll burn that bridge
* when we get to it.
*/
if (!(handle->aux_flags & PERF_AUX_FLAG_TRUNCATED)) {
arm_spe_perf_aux_output_begin(handle, event);
isb();
}
break;
case SPE_PMU_BUF_FAULT_ACT_SPURIOUS:
/* We've seen you before, but GCC has the memory of a sieve. */
break;
}
/* The buffer pointers are now sane, so resume profiling. */
write_sysreg_s(0, SYS_PMBSR_EL1);
return IRQ_HANDLED;
}
static u64 arm_spe_pmsevfr_res0(u16 pmsver)
{
switch (pmsver) {
case ID_AA64DFR0_EL1_PMSVer_IMP:
return PMSEVFR_EL1_RES0_IMP;
case ID_AA64DFR0_EL1_PMSVer_V1P1:
return PMSEVFR_EL1_RES0_V1P1;
case ID_AA64DFR0_EL1_PMSVer_V1P2:
/* Return the highest version we support in default */
default:
return PMSEVFR_EL1_RES0_V1P2;
}
}
/* Perf callbacks */
static int arm_spe_pmu_event_init(struct perf_event *event)
{
u64 reg;
struct perf_event_attr *attr = &event->attr;
struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
/* This is, of course, deeply driver-specific */
if (attr->type != event->pmu->type)
return -ENOENT;
if (event->cpu >= 0 &&
!cpumask_test_cpu(event->cpu, &spe_pmu->supported_cpus))
return -ENOENT;
if (arm_spe_event_to_pmsevfr(event) & arm_spe_pmsevfr_res0(spe_pmu->pmsver))
return -EOPNOTSUPP;
if (arm_spe_event_to_pmsnevfr(event) & arm_spe_pmsevfr_res0(spe_pmu->pmsver))
return -EOPNOTSUPP;
if (attr->exclude_idle)
return -EOPNOTSUPP;
/*
* Feedback-directed frequency throttling doesn't work when we
* have a buffer of samples. We'd need to manually count the
* samples in the buffer when it fills up and adjust the event
* count to reflect that. Instead, just force the user to specify
* a sample period.
*/
if (attr->freq)
return -EINVAL;
reg = arm_spe_event_to_pmsfcr(event);
if ((FIELD_GET(PMSFCR_EL1_FE, reg)) &&
!(spe_pmu->features & SPE_PMU_FEAT_FILT_EVT))
return -EOPNOTSUPP;
if ((FIELD_GET(PMSFCR_EL1_FnE, reg)) &&
!(spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT))
return -EOPNOTSUPP;
if ((FIELD_GET(PMSFCR_EL1_FT, reg)) &&
!(spe_pmu->features & SPE_PMU_FEAT_FILT_TYP))
return -EOPNOTSUPP;
if ((FIELD_GET(PMSFCR_EL1_FL, reg)) &&
!(spe_pmu->features & SPE_PMU_FEAT_FILT_LAT))
return -EOPNOTSUPP;
set_spe_event_has_cx(event);
reg = arm_spe_event_to_pmscr(event);
if (!perfmon_capable() &&
(reg & (PMSCR_EL1_PA | PMSCR_EL1_PCT)))
return -EACCES;
return 0;
}
static void arm_spe_pmu_start(struct perf_event *event, int flags)
{
u64 reg;
struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
struct perf_output_handle *handle = this_cpu_ptr(spe_pmu->handle);
hwc->state = 0;
arm_spe_perf_aux_output_begin(handle, event);
if (hwc->state)
return;
reg = arm_spe_event_to_pmsfcr(event);
write_sysreg_s(reg, SYS_PMSFCR_EL1);
reg = arm_spe_event_to_pmsevfr(event);
write_sysreg_s(reg, SYS_PMSEVFR_EL1);
if (spe_pmu->features & SPE_PMU_FEAT_INV_FILT_EVT) {
reg = arm_spe_event_to_pmsnevfr(event);
write_sysreg_s(reg, SYS_PMSNEVFR_EL1);
}
reg = arm_spe_event_to_pmslatfr(event);
write_sysreg_s(reg, SYS_PMSLATFR_EL1);
if (flags & PERF_EF_RELOAD) {
reg = arm_spe_event_to_pmsirr(event);
write_sysreg_s(reg, SYS_PMSIRR_EL1);
isb();
reg = local64_read(&hwc->period_left);
write_sysreg_s(reg, SYS_PMSICR_EL1);
}
reg = arm_spe_event_to_pmscr(event);
isb();
write_sysreg_s(reg, SYS_PMSCR_EL1);
}
static void arm_spe_pmu_stop(struct perf_event *event, int flags)
{
struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
struct perf_output_handle *handle = this_cpu_ptr(spe_pmu->handle);
/* If we're already stopped, then nothing to do */
if (hwc->state & PERF_HES_STOPPED)
return;
/* Stop all trace generation */
arm_spe_pmu_disable_and_drain_local();
if (flags & PERF_EF_UPDATE) {
/*
* If there's a fault pending then ensure we contain it
* to this buffer, since we might be on the context-switch
* path.
*/
if (perf_get_aux(handle)) {
enum arm_spe_pmu_buf_fault_action act;
act = arm_spe_pmu_buf_get_fault_act(handle);
if (act == SPE_PMU_BUF_FAULT_ACT_SPURIOUS)
arm_spe_perf_aux_output_end(handle);
else
write_sysreg_s(0, SYS_PMBSR_EL1);
}
/*
* This may also contain ECOUNT, but nobody else should
* be looking at period_left, since we forbid frequency
* based sampling.
*/
local64_set(&hwc->period_left, read_sysreg_s(SYS_PMSICR_EL1));
hwc->state |= PERF_HES_UPTODATE;
}
hwc->state |= PERF_HES_STOPPED;
}
static int arm_spe_pmu_add(struct perf_event *event, int flags)
{
int ret = 0;
struct arm_spe_pmu *spe_pmu = to_spe_pmu(event->pmu);
struct hw_perf_event *hwc = &event->hw;
int cpu = event->cpu == -1 ? smp_processor_id() : event->cpu;
if (!cpumask_test_cpu(cpu, &spe_pmu->supported_cpus))
return -ENOENT;
hwc->state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
if (flags & PERF_EF_START) {
arm_spe_pmu_start(event, PERF_EF_RELOAD);
if (hwc->state & PERF_HES_STOPPED)
ret = -EINVAL;
}
return ret;
}
static void arm_spe_pmu_del(struct perf_event *event, int flags)
{
arm_spe_pmu_stop(event, PERF_EF_UPDATE);
}
static void arm_spe_pmu_read(struct perf_event *event)
{
}
static void *arm_spe_pmu_setup_aux(struct perf_event *event, void **pages,
int nr_pages, bool snapshot)
{
int i, cpu = event->cpu;
struct page **pglist;
struct arm_spe_pmu_buf *buf;
/* We need at least two pages for this to work. */
if (nr_pages < 2)
return NULL;
/*
* We require an even number of pages for snapshot mode, so that
* we can effectively treat the buffer as consisting of two equal
* parts and give userspace a fighting chance of getting some
* useful data out of it.
*/
if (snapshot && (nr_pages & 1))
return NULL;
if (cpu == -1)
cpu = raw_smp_processor_id();
buf = kzalloc_node(sizeof(*buf), GFP_KERNEL, cpu_to_node(cpu));
if (!buf)
return NULL;
pglist = kcalloc(nr_pages, sizeof(*pglist), GFP_KERNEL);
if (!pglist)
goto out_free_buf;
for (i = 0; i < nr_pages; ++i)
pglist[i] = virt_to_page(pages[i]);
buf->base = vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
if (!buf->base)
goto out_free_pglist;
buf->nr_pages = nr_pages;
buf->snapshot = snapshot;
kfree(pglist);
return buf;
out_free_pglist:
kfree(pglist);
out_free_buf:
kfree(buf);
return NULL;
}
static void arm_spe_pmu_free_aux(void *aux)
{
struct arm_spe_pmu_buf *buf = aux;
vunmap(buf->base);
kfree(buf);
}
/* Initialisation and teardown functions */
static int arm_spe_pmu_perf_init(struct arm_spe_pmu *spe_pmu)
{
static atomic_t pmu_idx = ATOMIC_INIT(-1);
int idx;
char *name;
struct device *dev = &spe_pmu->pdev->dev;
spe_pmu->pmu = (struct pmu) {
.module = THIS_MODULE,
.capabilities = PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE,
.attr_groups = arm_spe_pmu_attr_groups,
/*
* We hitch a ride on the software context here, so that
* we can support per-task profiling (which is not possible
* with the invalid context as it doesn't get sched callbacks).
* This requires that userspace either uses a dummy event for
* perf_event_open, since the aux buffer is not setup until
* a subsequent mmap, or creates the profiling event in a
* disabled state and explicitly PERF_EVENT_IOC_ENABLEs it
* once the buffer has been created.
*/
.task_ctx_nr = perf_sw_context,
.event_init = arm_spe_pmu_event_init,
.add = arm_spe_pmu_add,
.del = arm_spe_pmu_del,
.start = arm_spe_pmu_start,
.stop = arm_spe_pmu_stop,
.read = arm_spe_pmu_read,
.setup_aux = arm_spe_pmu_setup_aux,
.free_aux = arm_spe_pmu_free_aux,
};
idx = atomic_inc_return(&pmu_idx);
name = devm_kasprintf(dev, GFP_KERNEL, "%s_%d", PMUNAME, idx);
if (!name) {
dev_err(dev, "failed to allocate name for pmu %d\n", idx);
return -ENOMEM;
}
return perf_pmu_register(&spe_pmu->pmu, name, -1);
}
static void arm_spe_pmu_perf_destroy(struct arm_spe_pmu *spe_pmu)
{
perf_pmu_unregister(&spe_pmu->pmu);
}
static void __arm_spe_pmu_dev_probe(void *info)
{
int fld;
u64 reg;
struct arm_spe_pmu *spe_pmu = info;
struct device *dev = &spe_pmu->pdev->dev;
fld = cpuid_feature_extract_unsigned_field(read_cpuid(ID_AA64DFR0_EL1),
ID_AA64DFR0_EL1_PMSVer_SHIFT);
if (!fld) {
dev_err(dev,
"unsupported ID_AA64DFR0_EL1.PMSVer [%d] on CPU %d\n",
fld, smp_processor_id());
return;
}
spe_pmu->pmsver = (u16)fld;
/* Read PMBIDR first to determine whether or not we have access */
reg = read_sysreg_s(SYS_PMBIDR_EL1);
if (FIELD_GET(PMBIDR_EL1_P, reg)) {
dev_err(dev,
"profiling buffer owned by higher exception level\n");
return;
}
/* Minimum alignment. If it's out-of-range, then fail the probe */
fld = FIELD_GET(PMBIDR_EL1_ALIGN, reg);
spe_pmu->align = 1 << fld;
if (spe_pmu->align > SZ_2K) {
dev_err(dev, "unsupported PMBIDR.Align [%d] on CPU %d\n",
fld, smp_processor_id());
return;
}
/* It's now safe to read PMSIDR and figure out what we've got */
reg = read_sysreg_s(SYS_PMSIDR_EL1);
if (FIELD_GET(PMSIDR_EL1_FE, reg))
spe_pmu->features |= SPE_PMU_FEAT_FILT_EVT;
if (FIELD_GET(PMSIDR_EL1_FnE, reg))
spe_pmu->features |= SPE_PMU_FEAT_INV_FILT_EVT;
if (FIELD_GET(PMSIDR_EL1_FT, reg))
spe_pmu->features |= SPE_PMU_FEAT_FILT_TYP;
if (FIELD_GET(PMSIDR_EL1_FL, reg))
spe_pmu->features |= SPE_PMU_FEAT_FILT_LAT;
if (FIELD_GET(PMSIDR_EL1_ARCHINST, reg))
spe_pmu->features |= SPE_PMU_FEAT_ARCH_INST;
if (FIELD_GET(PMSIDR_EL1_LDS, reg))
spe_pmu->features |= SPE_PMU_FEAT_LDS;
if (FIELD_GET(PMSIDR_EL1_ERND, reg))
spe_pmu->features |= SPE_PMU_FEAT_ERND;
/* This field has a spaced out encoding, so just use a look-up */
fld = FIELD_GET(PMSIDR_EL1_INTERVAL, reg);
switch (fld) {
case PMSIDR_EL1_INTERVAL_256:
spe_pmu->min_period = 256;
break;
case PMSIDR_EL1_INTERVAL_512:
spe_pmu->min_period = 512;
break;
case PMSIDR_EL1_INTERVAL_768:
spe_pmu->min_period = 768;
break;
case PMSIDR_EL1_INTERVAL_1024:
spe_pmu->min_period = 1024;
break;
case PMSIDR_EL1_INTERVAL_1536:
spe_pmu->min_period = 1536;
break;
case PMSIDR_EL1_INTERVAL_2048:
spe_pmu->min_period = 2048;
break;
case PMSIDR_EL1_INTERVAL_3072:
spe_pmu->min_period = 3072;
break;
default:
dev_warn(dev, "unknown PMSIDR_EL1.Interval [%d]; assuming 8\n",
fld);
fallthrough;
case PMSIDR_EL1_INTERVAL_4096:
spe_pmu->min_period = 4096;
}
/* Maximum record size. If it's out-of-range, then fail the probe */
fld = FIELD_GET(PMSIDR_EL1_MAXSIZE, reg);
spe_pmu->max_record_sz = 1 << fld;
if (spe_pmu->max_record_sz > SZ_2K || spe_pmu->max_record_sz < 16) {
dev_err(dev, "unsupported PMSIDR_EL1.MaxSize [%d] on CPU %d\n",
fld, smp_processor_id());
return;
}
fld = FIELD_GET(PMSIDR_EL1_COUNTSIZE, reg);
switch (fld) {
default:
dev_warn(dev, "unknown PMSIDR_EL1.CountSize [%d]; assuming 2\n",
fld);
fallthrough;
case PMSIDR_EL1_COUNTSIZE_12_BIT_SAT:
spe_pmu->counter_sz = 12;
break;
case PMSIDR_EL1_COUNTSIZE_16_BIT_SAT:
spe_pmu->counter_sz = 16;
}
dev_info(dev,
"probed SPEv1.%d for CPUs %*pbl [max_record_sz %u, align %u, features 0x%llx]\n",
spe_pmu->pmsver - 1, cpumask_pr_args(&spe_pmu->supported_cpus),
spe_pmu->max_record_sz, spe_pmu->align, spe_pmu->features);
spe_pmu->features |= SPE_PMU_FEAT_DEV_PROBED;
}
static void __arm_spe_pmu_reset_local(void)
{
/*
* This is probably overkill, as we have no idea where we're
* draining any buffered data to...
*/
arm_spe_pmu_disable_and_drain_local();
/* Reset the buffer base pointer */
write_sysreg_s(0, SYS_PMBPTR_EL1);
isb();
/* Clear any pending management interrupts */
write_sysreg_s(0, SYS_PMBSR_EL1);
isb();
}
static void __arm_spe_pmu_setup_one(void *info)
{
struct arm_spe_pmu *spe_pmu = info;
__arm_spe_pmu_reset_local();
enable_percpu_irq(spe_pmu->irq, IRQ_TYPE_NONE);
}
static void __arm_spe_pmu_stop_one(void *info)
{
struct arm_spe_pmu *spe_pmu = info;
disable_percpu_irq(spe_pmu->irq);
__arm_spe_pmu_reset_local();
}
static int arm_spe_pmu_cpu_startup(unsigned int cpu, struct hlist_node *node)
{
struct arm_spe_pmu *spe_pmu;
spe_pmu = hlist_entry_safe(node, struct arm_spe_pmu, hotplug_node);
if (!cpumask_test_cpu(cpu, &spe_pmu->supported_cpus))
return 0;
__arm_spe_pmu_setup_one(spe_pmu);
return 0;
}
static int arm_spe_pmu_cpu_teardown(unsigned int cpu, struct hlist_node *node)
{
struct arm_spe_pmu *spe_pmu;
spe_pmu = hlist_entry_safe(node, struct arm_spe_pmu, hotplug_node);
if (!cpumask_test_cpu(cpu, &spe_pmu->supported_cpus))
return 0;
__arm_spe_pmu_stop_one(spe_pmu);
return 0;
}
static int arm_spe_pmu_dev_init(struct arm_spe_pmu *spe_pmu)
{
int ret;
cpumask_t *mask = &spe_pmu->supported_cpus;
/* Make sure we probe the hardware on a relevant CPU */
ret = smp_call_function_any(mask, __arm_spe_pmu_dev_probe, spe_pmu, 1);
if (ret || !(spe_pmu->features & SPE_PMU_FEAT_DEV_PROBED))
return -ENXIO;
/* Request our PPIs (note that the IRQ is still disabled) */
ret = request_percpu_irq(spe_pmu->irq, arm_spe_pmu_irq_handler, DRVNAME,
spe_pmu->handle);
if (ret)
return ret;
/*
* Register our hotplug notifier now so we don't miss any events.
* This will enable the IRQ for any supported CPUs that are already
* up.
*/
ret = cpuhp_state_add_instance(arm_spe_pmu_online,
&spe_pmu->hotplug_node);
if (ret)
free_percpu_irq(spe_pmu->irq, spe_pmu->handle);
return ret;
}
static void arm_spe_pmu_dev_teardown(struct arm_spe_pmu *spe_pmu)
{
cpuhp_state_remove_instance(arm_spe_pmu_online, &spe_pmu->hotplug_node);
free_percpu_irq(spe_pmu->irq, spe_pmu->handle);
}
/* Driver and device probing */
static int arm_spe_pmu_irq_probe(struct arm_spe_pmu *spe_pmu)
{
struct platform_device *pdev = spe_pmu->pdev;
int irq = platform_get_irq(pdev, 0);
if (irq < 0)
return -ENXIO;
if (!irq_is_percpu(irq)) {
dev_err(&pdev->dev, "expected PPI but got SPI (%d)\n", irq);
return -EINVAL;
}
if (irq_get_percpu_devid_partition(irq, &spe_pmu->supported_cpus)) {
dev_err(&pdev->dev, "failed to get PPI partition (%d)\n", irq);
return -EINVAL;
}
spe_pmu->irq = irq;
return 0;
}
static const struct of_device_id arm_spe_pmu_of_match[] = {
{ .compatible = "arm,statistical-profiling-extension-v1", .data = (void *)1 },
{ /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, arm_spe_pmu_of_match);
static const struct platform_device_id arm_spe_match[] = {
{ ARMV8_SPE_PDEV_NAME, 0},
{ }
};
MODULE_DEVICE_TABLE(platform, arm_spe_match);
static int arm_spe_pmu_device_probe(struct platform_device *pdev)
{
int ret;
struct arm_spe_pmu *spe_pmu;
struct device *dev = &pdev->dev;
/*
* If kernelspace is unmapped when running at EL0, then the SPE
* buffer will fault and prematurely terminate the AUX session.
*/
if (arm64_kernel_unmapped_at_el0()) {
dev_warn_once(dev, "profiling buffer inaccessible. Try passing \"kpti=off\" on the kernel command line\n");
return -EPERM;
}
spe_pmu = devm_kzalloc(dev, sizeof(*spe_pmu), GFP_KERNEL);
if (!spe_pmu)
return -ENOMEM;
spe_pmu->handle = alloc_percpu(typeof(*spe_pmu->handle));
if (!spe_pmu->handle)
return -ENOMEM;
spe_pmu->pdev = pdev;
platform_set_drvdata(pdev, spe_pmu);
ret = arm_spe_pmu_irq_probe(spe_pmu);
if (ret)
goto out_free_handle;
ret = arm_spe_pmu_dev_init(spe_pmu);
if (ret)
goto out_free_handle;
ret = arm_spe_pmu_perf_init(spe_pmu);
if (ret)
goto out_teardown_dev;
return 0;
out_teardown_dev:
arm_spe_pmu_dev_teardown(spe_pmu);
out_free_handle:
free_percpu(spe_pmu->handle);
return ret;
}
static int arm_spe_pmu_device_remove(struct platform_device *pdev)
{
struct arm_spe_pmu *spe_pmu = platform_get_drvdata(pdev);
arm_spe_pmu_perf_destroy(spe_pmu);
arm_spe_pmu_dev_teardown(spe_pmu);
free_percpu(spe_pmu->handle);
return 0;
}
static struct platform_driver arm_spe_pmu_driver = {
.id_table = arm_spe_match,
.driver = {
.name = DRVNAME,
.of_match_table = of_match_ptr(arm_spe_pmu_of_match),
.suppress_bind_attrs = true,
},
.probe = arm_spe_pmu_device_probe,
.remove = arm_spe_pmu_device_remove,
};
static int __init arm_spe_pmu_init(void)
{
int ret;
ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, DRVNAME,
arm_spe_pmu_cpu_startup,
arm_spe_pmu_cpu_teardown);
if (ret < 0)
return ret;
arm_spe_pmu_online = ret;
ret = platform_driver_register(&arm_spe_pmu_driver);
if (ret)
cpuhp_remove_multi_state(arm_spe_pmu_online);
return ret;
}
static void __exit arm_spe_pmu_exit(void)
{
platform_driver_unregister(&arm_spe_pmu_driver);
cpuhp_remove_multi_state(arm_spe_pmu_online);
}
module_init(arm_spe_pmu_init);
module_exit(arm_spe_pmu_exit);
MODULE_DESCRIPTION("Perf driver for the ARMv8.2 Statistical Profiling Extension");
MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
MODULE_LICENSE("GPL v2");