/*
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* Intel(R) Processor Trace PMU driver for perf
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* Copyright (c) 2013-2014, Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* Intel PT is specified in the Intel Architecture Instruction Set Extensions
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* Programming Reference:
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* http://software.intel.com/en-us/intel-isa-extensions
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*/
|
|
#undef DEBUG
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/device.h>
|
|
#include <asm/perf_event.h>
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#include <asm/insn.h>
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#include <asm/io.h>
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#include <asm/intel_pt.h>
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#include <asm/intel-family.h>
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#include "../perf_event.h"
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#include "pt.h"
|
|
static DEFINE_PER_CPU(struct pt, pt_ctx);
|
|
static struct pt_pmu pt_pmu;
|
|
/*
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* Capabilities of Intel PT hardware, such as number of address bits or
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* supported output schemes, are cached and exported to userspace as "caps"
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* attribute group of pt pmu device
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* (/sys/bus/event_source/devices/intel_pt/caps/) so that userspace can store
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* relevant bits together with intel_pt traces.
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*
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* These are necessary for both trace decoding (payloads_lip, contains address
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* width encoded in IP-related packets), and event configuration (bitmasks with
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* permitted values for certain bit fields).
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*/
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#define PT_CAP(_n, _l, _r, _m) \
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[PT_CAP_ ## _n] = { .name = __stringify(_n), .leaf = _l, \
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.reg = _r, .mask = _m }
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static struct pt_cap_desc {
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const char *name;
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u32 leaf;
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u8 reg;
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u32 mask;
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} pt_caps[] = {
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PT_CAP(max_subleaf, 0, CPUID_EAX, 0xffffffff),
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PT_CAP(cr3_filtering, 0, CPUID_EBX, BIT(0)),
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PT_CAP(psb_cyc, 0, CPUID_EBX, BIT(1)),
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PT_CAP(ip_filtering, 0, CPUID_EBX, BIT(2)),
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PT_CAP(mtc, 0, CPUID_EBX, BIT(3)),
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PT_CAP(ptwrite, 0, CPUID_EBX, BIT(4)),
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PT_CAP(power_event_trace, 0, CPUID_EBX, BIT(5)),
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PT_CAP(topa_output, 0, CPUID_ECX, BIT(0)),
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PT_CAP(topa_multiple_entries, 0, CPUID_ECX, BIT(1)),
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PT_CAP(single_range_output, 0, CPUID_ECX, BIT(2)),
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PT_CAP(payloads_lip, 0, CPUID_ECX, BIT(31)),
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PT_CAP(num_address_ranges, 1, CPUID_EAX, 0x7),
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PT_CAP(mtc_periods, 1, CPUID_EAX, 0xffff0000),
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PT_CAP(cycle_thresholds, 1, CPUID_EBX, 0xffff),
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PT_CAP(psb_periods, 1, CPUID_EBX, 0xffff0000),
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};
|
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static u32 pt_cap_get(enum pt_capabilities cap)
|
{
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struct pt_cap_desc *cd = &pt_caps[cap];
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u32 c = pt_pmu.caps[cd->leaf * PT_CPUID_REGS_NUM + cd->reg];
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unsigned int shift = __ffs(cd->mask);
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return (c & cd->mask) >> shift;
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}
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static ssize_t pt_cap_show(struct device *cdev,
|
struct device_attribute *attr,
|
char *buf)
|
{
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struct dev_ext_attribute *ea =
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container_of(attr, struct dev_ext_attribute, attr);
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enum pt_capabilities cap = (long)ea->var;
|
|
return snprintf(buf, PAGE_SIZE, "%x\n", pt_cap_get(cap));
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}
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static struct attribute_group pt_cap_group = {
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.name = "caps",
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};
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PMU_FORMAT_ATTR(pt, "config:0" );
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PMU_FORMAT_ATTR(cyc, "config:1" );
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PMU_FORMAT_ATTR(pwr_evt, "config:4" );
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PMU_FORMAT_ATTR(fup_on_ptw, "config:5" );
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PMU_FORMAT_ATTR(mtc, "config:9" );
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PMU_FORMAT_ATTR(tsc, "config:10" );
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PMU_FORMAT_ATTR(noretcomp, "config:11" );
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PMU_FORMAT_ATTR(ptw, "config:12" );
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PMU_FORMAT_ATTR(branch, "config:13" );
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PMU_FORMAT_ATTR(mtc_period, "config:14-17" );
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PMU_FORMAT_ATTR(cyc_thresh, "config:19-22" );
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PMU_FORMAT_ATTR(psb_period, "config:24-27" );
|
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static struct attribute *pt_formats_attr[] = {
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&format_attr_pt.attr,
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&format_attr_cyc.attr,
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&format_attr_pwr_evt.attr,
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&format_attr_fup_on_ptw.attr,
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&format_attr_mtc.attr,
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&format_attr_tsc.attr,
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&format_attr_noretcomp.attr,
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&format_attr_ptw.attr,
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&format_attr_branch.attr,
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&format_attr_mtc_period.attr,
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&format_attr_cyc_thresh.attr,
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&format_attr_psb_period.attr,
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NULL,
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};
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static struct attribute_group pt_format_group = {
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.name = "format",
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.attrs = pt_formats_attr,
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};
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|
static ssize_t
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pt_timing_attr_show(struct device *dev, struct device_attribute *attr,
|
char *page)
|
{
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struct perf_pmu_events_attr *pmu_attr =
|
container_of(attr, struct perf_pmu_events_attr, attr);
|
|
switch (pmu_attr->id) {
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case 0:
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return sprintf(page, "%lu\n", pt_pmu.max_nonturbo_ratio);
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case 1:
|
return sprintf(page, "%u:%u\n",
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pt_pmu.tsc_art_num,
|
pt_pmu.tsc_art_den);
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default:
|
break;
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}
|
|
return -EINVAL;
|
}
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PMU_EVENT_ATTR(max_nonturbo_ratio, timing_attr_max_nonturbo_ratio, 0,
|
pt_timing_attr_show);
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PMU_EVENT_ATTR(tsc_art_ratio, timing_attr_tsc_art_ratio, 1,
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pt_timing_attr_show);
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static struct attribute *pt_timing_attr[] = {
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&timing_attr_max_nonturbo_ratio.attr.attr,
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&timing_attr_tsc_art_ratio.attr.attr,
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NULL,
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};
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static struct attribute_group pt_timing_group = {
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.attrs = pt_timing_attr,
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};
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static const struct attribute_group *pt_attr_groups[] = {
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&pt_cap_group,
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&pt_format_group,
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&pt_timing_group,
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NULL,
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};
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static int __init pt_pmu_hw_init(void)
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{
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struct dev_ext_attribute *de_attrs;
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struct attribute **attrs;
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size_t size;
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u64 reg;
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int ret;
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long i;
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rdmsrl(MSR_PLATFORM_INFO, reg);
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pt_pmu.max_nonturbo_ratio = (reg & 0xff00) >> 8;
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/*
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* if available, read in TSC to core crystal clock ratio,
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* otherwise, zero for numerator stands for "not enumerated"
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* as per SDM
|
*/
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if (boot_cpu_data.cpuid_level >= CPUID_TSC_LEAF) {
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u32 eax, ebx, ecx, edx;
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cpuid(CPUID_TSC_LEAF, &eax, &ebx, &ecx, &edx);
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pt_pmu.tsc_art_num = ebx;
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pt_pmu.tsc_art_den = eax;
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}
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/* model-specific quirks */
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switch (boot_cpu_data.x86_model) {
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case INTEL_FAM6_BROADWELL_CORE:
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case INTEL_FAM6_BROADWELL_XEON_D:
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case INTEL_FAM6_BROADWELL_GT3E:
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case INTEL_FAM6_BROADWELL_X:
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/* not setting BRANCH_EN will #GP, erratum BDM106 */
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pt_pmu.branch_en_always_on = true;
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break;
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default:
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break;
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}
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if (boot_cpu_has(X86_FEATURE_VMX)) {
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/*
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* Intel SDM, 36.5 "Tracing post-VMXON" says that
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* "IA32_VMX_MISC[bit 14]" being 1 means PT can trace
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* post-VMXON.
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*/
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rdmsrl(MSR_IA32_VMX_MISC, reg);
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if (reg & BIT(14))
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pt_pmu.vmx = true;
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}
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attrs = NULL;
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for (i = 0; i < PT_CPUID_LEAVES; i++) {
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cpuid_count(20, i,
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&pt_pmu.caps[CPUID_EAX + i*PT_CPUID_REGS_NUM],
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&pt_pmu.caps[CPUID_EBX + i*PT_CPUID_REGS_NUM],
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&pt_pmu.caps[CPUID_ECX + i*PT_CPUID_REGS_NUM],
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&pt_pmu.caps[CPUID_EDX + i*PT_CPUID_REGS_NUM]);
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}
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ret = -ENOMEM;
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size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps)+1);
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attrs = kzalloc(size, GFP_KERNEL);
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if (!attrs)
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goto fail;
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size = sizeof(struct dev_ext_attribute) * (ARRAY_SIZE(pt_caps)+1);
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de_attrs = kzalloc(size, GFP_KERNEL);
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if (!de_attrs)
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goto fail;
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|
for (i = 0; i < ARRAY_SIZE(pt_caps); i++) {
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struct dev_ext_attribute *de_attr = de_attrs + i;
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de_attr->attr.attr.name = pt_caps[i].name;
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sysfs_attr_init(&de_attr->attr.attr);
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de_attr->attr.attr.mode = S_IRUGO;
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de_attr->attr.show = pt_cap_show;
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de_attr->var = (void *)i;
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attrs[i] = &de_attr->attr.attr;
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}
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pt_cap_group.attrs = attrs;
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return 0;
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fail:
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kfree(attrs);
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|
return ret;
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}
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#define RTIT_CTL_CYC_PSB (RTIT_CTL_CYCLEACC | \
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RTIT_CTL_CYC_THRESH | \
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RTIT_CTL_PSB_FREQ)
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#define RTIT_CTL_MTC (RTIT_CTL_MTC_EN | \
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RTIT_CTL_MTC_RANGE)
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#define RTIT_CTL_PTW (RTIT_CTL_PTW_EN | \
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RTIT_CTL_FUP_ON_PTW)
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/*
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* Bit 0 (TraceEn) in the attr.config is meaningless as the
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* corresponding bit in the RTIT_CTL can only be controlled
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* by the driver; therefore, repurpose it to mean: pass
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* through the bit that was previously assumed to be always
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* on for PT, thereby allowing the user to *not* set it if
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* they so wish. See also pt_event_valid() and pt_config().
|
*/
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#define RTIT_CTL_PASSTHROUGH RTIT_CTL_TRACEEN
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#define PT_CONFIG_MASK (RTIT_CTL_TRACEEN | \
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RTIT_CTL_TSC_EN | \
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RTIT_CTL_DISRETC | \
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RTIT_CTL_BRANCH_EN | \
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RTIT_CTL_CYC_PSB | \
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RTIT_CTL_MTC | \
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RTIT_CTL_PWR_EVT_EN | \
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RTIT_CTL_FUP_ON_PTW | \
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RTIT_CTL_PTW_EN)
|
|
static bool pt_event_valid(struct perf_event *event)
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{
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u64 config = event->attr.config;
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u64 allowed, requested;
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if ((config & PT_CONFIG_MASK) != config)
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return false;
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if (config & RTIT_CTL_CYC_PSB) {
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if (!pt_cap_get(PT_CAP_psb_cyc))
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return false;
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allowed = pt_cap_get(PT_CAP_psb_periods);
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requested = (config & RTIT_CTL_PSB_FREQ) >>
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RTIT_CTL_PSB_FREQ_OFFSET;
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if (requested && (!(allowed & BIT(requested))))
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return false;
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allowed = pt_cap_get(PT_CAP_cycle_thresholds);
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requested = (config & RTIT_CTL_CYC_THRESH) >>
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RTIT_CTL_CYC_THRESH_OFFSET;
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if (requested && (!(allowed & BIT(requested))))
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return false;
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}
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if (config & RTIT_CTL_MTC) {
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/*
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* In the unlikely case that CPUID lists valid mtc periods,
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* but not the mtc capability, drop out here.
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*
|
* Spec says that setting mtc period bits while mtc bit in
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* CPUID is 0 will #GP, so better safe than sorry.
|
*/
|
if (!pt_cap_get(PT_CAP_mtc))
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return false;
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allowed = pt_cap_get(PT_CAP_mtc_periods);
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if (!allowed)
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return false;
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requested = (config & RTIT_CTL_MTC_RANGE) >>
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RTIT_CTL_MTC_RANGE_OFFSET;
|
|
if (!(allowed & BIT(requested)))
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return false;
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}
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if (config & RTIT_CTL_PWR_EVT_EN &&
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!pt_cap_get(PT_CAP_power_event_trace))
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return false;
|
|
if (config & RTIT_CTL_PTW) {
|
if (!pt_cap_get(PT_CAP_ptwrite))
|
return false;
|
|
/* FUPonPTW without PTW doesn't make sense */
|
if ((config & RTIT_CTL_FUP_ON_PTW) &&
|
!(config & RTIT_CTL_PTW_EN))
|
return false;
|
}
|
|
/*
|
* Setting bit 0 (TraceEn in RTIT_CTL MSR) in the attr.config
|
* clears the assomption that BranchEn must always be enabled,
|
* as was the case with the first implementation of PT.
|
* If this bit is not set, the legacy behavior is preserved
|
* for compatibility with the older userspace.
|
*
|
* Re-using bit 0 for this purpose is fine because it is never
|
* directly set by the user; previous attempts at setting it in
|
* the attr.config resulted in -EINVAL.
|
*/
|
if (config & RTIT_CTL_PASSTHROUGH) {
|
/*
|
* Disallow not setting BRANCH_EN where BRANCH_EN is
|
* always required.
|
*/
|
if (pt_pmu.branch_en_always_on &&
|
!(config & RTIT_CTL_BRANCH_EN))
|
return false;
|
} else {
|
/*
|
* Disallow BRANCH_EN without the PASSTHROUGH.
|
*/
|
if (config & RTIT_CTL_BRANCH_EN)
|
return false;
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}
|
|
return true;
|
}
|
|
/*
|
* PT configuration helpers
|
* These all are cpu affine and operate on a local PT
|
*/
|
|
/* Address ranges and their corresponding msr configuration registers */
|
static const struct pt_address_range {
|
unsigned long msr_a;
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unsigned long msr_b;
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unsigned int reg_off;
|
} pt_address_ranges[] = {
|
{
|
.msr_a = MSR_IA32_RTIT_ADDR0_A,
|
.msr_b = MSR_IA32_RTIT_ADDR0_B,
|
.reg_off = RTIT_CTL_ADDR0_OFFSET,
|
},
|
{
|
.msr_a = MSR_IA32_RTIT_ADDR1_A,
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.msr_b = MSR_IA32_RTIT_ADDR1_B,
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.reg_off = RTIT_CTL_ADDR1_OFFSET,
|
},
|
{
|
.msr_a = MSR_IA32_RTIT_ADDR2_A,
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.msr_b = MSR_IA32_RTIT_ADDR2_B,
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.reg_off = RTIT_CTL_ADDR2_OFFSET,
|
},
|
{
|
.msr_a = MSR_IA32_RTIT_ADDR3_A,
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.msr_b = MSR_IA32_RTIT_ADDR3_B,
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.reg_off = RTIT_CTL_ADDR3_OFFSET,
|
}
|
};
|
|
static u64 pt_config_filters(struct perf_event *event)
|
{
|
struct pt_filters *filters = event->hw.addr_filters;
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
unsigned int range = 0;
|
u64 rtit_ctl = 0;
|
|
if (!filters)
|
return 0;
|
|
perf_event_addr_filters_sync(event);
|
|
for (range = 0; range < filters->nr_filters; range++) {
|
struct pt_filter *filter = &filters->filter[range];
|
|
/*
|
* Note, if the range has zero start/end addresses due
|
* to its dynamic object not being loaded yet, we just
|
* go ahead and program zeroed range, which will simply
|
* produce no data. Note^2: if executable code at 0x0
|
* is a concern, we can set up an "invalid" configuration
|
* such as msr_b < msr_a.
|
*/
|
|
/* avoid redundant msr writes */
|
if (pt->filters.filter[range].msr_a != filter->msr_a) {
|
wrmsrl(pt_address_ranges[range].msr_a, filter->msr_a);
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pt->filters.filter[range].msr_a = filter->msr_a;
|
}
|
|
if (pt->filters.filter[range].msr_b != filter->msr_b) {
|
wrmsrl(pt_address_ranges[range].msr_b, filter->msr_b);
|
pt->filters.filter[range].msr_b = filter->msr_b;
|
}
|
|
rtit_ctl |= filter->config << pt_address_ranges[range].reg_off;
|
}
|
|
return rtit_ctl;
|
}
|
|
static void pt_config(struct perf_event *event)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
u64 reg;
|
|
/* First round: clear STATUS, in particular the PSB byte counter. */
|
if (!event->hw.config) {
|
perf_event_itrace_started(event);
|
wrmsrl(MSR_IA32_RTIT_STATUS, 0);
|
}
|
|
reg = pt_config_filters(event);
|
reg |= RTIT_CTL_TOPA | RTIT_CTL_TRACEEN;
|
|
/*
|
* Previously, we had BRANCH_EN on by default, but now that PT has
|
* grown features outside of branch tracing, it is useful to allow
|
* the user to disable it. Setting bit 0 in the event's attr.config
|
* allows BRANCH_EN to pass through instead of being always on. See
|
* also the comment in pt_event_valid().
|
*/
|
if (event->attr.config & BIT(0)) {
|
reg |= event->attr.config & RTIT_CTL_BRANCH_EN;
|
} else {
|
reg |= RTIT_CTL_BRANCH_EN;
|
}
|
|
if (!event->attr.exclude_kernel)
|
reg |= RTIT_CTL_OS;
|
if (!event->attr.exclude_user)
|
reg |= RTIT_CTL_USR;
|
|
reg |= (event->attr.config & PT_CONFIG_MASK);
|
|
event->hw.config = reg;
|
if (READ_ONCE(pt->vmx_on))
|
perf_aux_output_flag(&pt->handle, PERF_AUX_FLAG_PARTIAL);
|
else
|
wrmsrl(MSR_IA32_RTIT_CTL, reg);
|
}
|
|
static void pt_config_stop(struct perf_event *event)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
u64 ctl = READ_ONCE(event->hw.config);
|
|
/* may be already stopped by a PMI */
|
if (!(ctl & RTIT_CTL_TRACEEN))
|
return;
|
|
ctl &= ~RTIT_CTL_TRACEEN;
|
if (!READ_ONCE(pt->vmx_on))
|
wrmsrl(MSR_IA32_RTIT_CTL, ctl);
|
|
WRITE_ONCE(event->hw.config, ctl);
|
|
/*
|
* A wrmsr that disables trace generation serializes other PT
|
* registers and causes all data packets to be written to memory,
|
* but a fence is required for the data to become globally visible.
|
*
|
* The below WMB, separating data store and aux_head store matches
|
* the consumer's RMB that separates aux_head load and data load.
|
*/
|
wmb();
|
}
|
|
static void pt_config_buffer(void *buf, unsigned int topa_idx,
|
unsigned int output_off)
|
{
|
u64 reg;
|
|
wrmsrl(MSR_IA32_RTIT_OUTPUT_BASE, virt_to_phys(buf));
|
|
reg = 0x7f | ((u64)topa_idx << 7) | ((u64)output_off << 32);
|
|
wrmsrl(MSR_IA32_RTIT_OUTPUT_MASK, reg);
|
}
|
|
/*
|
* Keep ToPA table-related metadata on the same page as the actual table,
|
* taking up a few words from the top
|
*/
|
|
#define TENTS_PER_PAGE (((PAGE_SIZE - 40) / sizeof(struct topa_entry)) - 1)
|
|
/**
|
* struct topa - page-sized ToPA table with metadata at the top
|
* @table: actual ToPA table entries, as understood by PT hardware
|
* @list: linkage to struct pt_buffer's list of tables
|
* @phys: physical address of this page
|
* @offset: offset of the first entry in this table in the buffer
|
* @size: total size of all entries in this table
|
* @last: index of the last initialized entry in this table
|
*/
|
struct topa {
|
struct topa_entry table[TENTS_PER_PAGE];
|
struct list_head list;
|
u64 phys;
|
u64 offset;
|
size_t size;
|
int last;
|
};
|
|
/* make -1 stand for the last table entry */
|
#define TOPA_ENTRY(t, i) ((i) == -1 ? &(t)->table[(t)->last] : &(t)->table[(i)])
|
|
/**
|
* topa_alloc() - allocate page-sized ToPA table
|
* @cpu: CPU on which to allocate.
|
* @gfp: Allocation flags.
|
*
|
* Return: On success, return the pointer to ToPA table page.
|
*/
|
static struct topa *topa_alloc(int cpu, gfp_t gfp)
|
{
|
int node = cpu_to_node(cpu);
|
struct topa *topa;
|
struct page *p;
|
|
p = alloc_pages_node(node, gfp | __GFP_ZERO, 0);
|
if (!p)
|
return NULL;
|
|
topa = page_address(p);
|
topa->last = 0;
|
topa->phys = page_to_phys(p);
|
|
/*
|
* In case of singe-entry ToPA, always put the self-referencing END
|
* link as the 2nd entry in the table
|
*/
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries)) {
|
TOPA_ENTRY(topa, 1)->base = topa->phys >> TOPA_SHIFT;
|
TOPA_ENTRY(topa, 1)->end = 1;
|
}
|
|
return topa;
|
}
|
|
/**
|
* topa_free() - free a page-sized ToPA table
|
* @topa: Table to deallocate.
|
*/
|
static void topa_free(struct topa *topa)
|
{
|
free_page((unsigned long)topa);
|
}
|
|
/**
|
* topa_insert_table() - insert a ToPA table into a buffer
|
* @buf: PT buffer that's being extended.
|
* @topa: New topa table to be inserted.
|
*
|
* If it's the first table in this buffer, set up buffer's pointers
|
* accordingly; otherwise, add a END=1 link entry to @topa to the current
|
* "last" table and adjust the last table pointer to @topa.
|
*/
|
static void topa_insert_table(struct pt_buffer *buf, struct topa *topa)
|
{
|
struct topa *last = buf->last;
|
|
list_add_tail(&topa->list, &buf->tables);
|
|
if (!buf->first) {
|
buf->first = buf->last = buf->cur = topa;
|
return;
|
}
|
|
topa->offset = last->offset + last->size;
|
buf->last = topa;
|
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries))
|
return;
|
|
BUG_ON(last->last != TENTS_PER_PAGE - 1);
|
|
TOPA_ENTRY(last, -1)->base = topa->phys >> TOPA_SHIFT;
|
TOPA_ENTRY(last, -1)->end = 1;
|
}
|
|
/**
|
* topa_table_full() - check if a ToPA table is filled up
|
* @topa: ToPA table.
|
*/
|
static bool topa_table_full(struct topa *topa)
|
{
|
/* single-entry ToPA is a special case */
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries))
|
return !!topa->last;
|
|
return topa->last == TENTS_PER_PAGE - 1;
|
}
|
|
/**
|
* topa_insert_pages() - create a list of ToPA tables
|
* @buf: PT buffer being initialized.
|
* @gfp: Allocation flags.
|
*
|
* This initializes a list of ToPA tables with entries from
|
* the data_pages provided by rb_alloc_aux().
|
*
|
* Return: 0 on success or error code.
|
*/
|
static int topa_insert_pages(struct pt_buffer *buf, gfp_t gfp)
|
{
|
struct topa *topa = buf->last;
|
int order = 0;
|
struct page *p;
|
|
p = virt_to_page(buf->data_pages[buf->nr_pages]);
|
if (PagePrivate(p))
|
order = page_private(p);
|
|
if (topa_table_full(topa)) {
|
topa = topa_alloc(buf->cpu, gfp);
|
if (!topa)
|
return -ENOMEM;
|
|
topa_insert_table(buf, topa);
|
}
|
|
TOPA_ENTRY(topa, -1)->base = page_to_phys(p) >> TOPA_SHIFT;
|
TOPA_ENTRY(topa, -1)->size = order;
|
if (!buf->snapshot && !pt_cap_get(PT_CAP_topa_multiple_entries)) {
|
TOPA_ENTRY(topa, -1)->intr = 1;
|
TOPA_ENTRY(topa, -1)->stop = 1;
|
}
|
|
topa->last++;
|
topa->size += sizes(order);
|
|
buf->nr_pages += 1ul << order;
|
|
return 0;
|
}
|
|
/**
|
* pt_topa_dump() - print ToPA tables and their entries
|
* @buf: PT buffer.
|
*/
|
static void pt_topa_dump(struct pt_buffer *buf)
|
{
|
struct topa *topa;
|
|
list_for_each_entry(topa, &buf->tables, list) {
|
int i;
|
|
pr_debug("# table @%p (%016Lx), off %llx size %zx\n", topa->table,
|
topa->phys, topa->offset, topa->size);
|
for (i = 0; i < TENTS_PER_PAGE; i++) {
|
pr_debug("# entry @%p (%lx sz %u %c%c%c) raw=%16llx\n",
|
&topa->table[i],
|
(unsigned long)topa->table[i].base << TOPA_SHIFT,
|
sizes(topa->table[i].size),
|
topa->table[i].end ? 'E' : ' ',
|
topa->table[i].intr ? 'I' : ' ',
|
topa->table[i].stop ? 'S' : ' ',
|
*(u64 *)&topa->table[i]);
|
if ((pt_cap_get(PT_CAP_topa_multiple_entries) &&
|
topa->table[i].stop) ||
|
topa->table[i].end)
|
break;
|
}
|
}
|
}
|
|
/**
|
* pt_buffer_advance() - advance to the next output region
|
* @buf: PT buffer.
|
*
|
* Advance the current pointers in the buffer to the next ToPA entry.
|
*/
|
static void pt_buffer_advance(struct pt_buffer *buf)
|
{
|
buf->output_off = 0;
|
buf->cur_idx++;
|
|
if (buf->cur_idx == buf->cur->last) {
|
if (buf->cur == buf->last)
|
buf->cur = buf->first;
|
else
|
buf->cur = list_entry(buf->cur->list.next, struct topa,
|
list);
|
buf->cur_idx = 0;
|
}
|
}
|
|
/**
|
* pt_update_head() - calculate current offsets and sizes
|
* @pt: Per-cpu pt context.
|
*
|
* Update buffer's current write pointer position and data size.
|
*/
|
static void pt_update_head(struct pt *pt)
|
{
|
struct pt_buffer *buf = perf_get_aux(&pt->handle);
|
u64 topa_idx, base, old;
|
|
/* offset of the first region in this table from the beginning of buf */
|
base = buf->cur->offset + buf->output_off;
|
|
/* offset of the current output region within this table */
|
for (topa_idx = 0; topa_idx < buf->cur_idx; topa_idx++)
|
base += sizes(buf->cur->table[topa_idx].size);
|
|
if (buf->snapshot) {
|
local_set(&buf->data_size, base);
|
} else {
|
old = (local64_xchg(&buf->head, base) &
|
((buf->nr_pages << PAGE_SHIFT) - 1));
|
if (base < old)
|
base += buf->nr_pages << PAGE_SHIFT;
|
|
local_add(base - old, &buf->data_size);
|
}
|
}
|
|
/**
|
* pt_buffer_region() - obtain current output region's address
|
* @buf: PT buffer.
|
*/
|
static void *pt_buffer_region(struct pt_buffer *buf)
|
{
|
return phys_to_virt(buf->cur->table[buf->cur_idx].base << TOPA_SHIFT);
|
}
|
|
/**
|
* pt_buffer_region_size() - obtain current output region's size
|
* @buf: PT buffer.
|
*/
|
static size_t pt_buffer_region_size(struct pt_buffer *buf)
|
{
|
return sizes(buf->cur->table[buf->cur_idx].size);
|
}
|
|
/**
|
* pt_handle_status() - take care of possible status conditions
|
* @pt: Per-cpu pt context.
|
*/
|
static void pt_handle_status(struct pt *pt)
|
{
|
struct pt_buffer *buf = perf_get_aux(&pt->handle);
|
int advance = 0;
|
u64 status;
|
|
rdmsrl(MSR_IA32_RTIT_STATUS, status);
|
|
if (status & RTIT_STATUS_ERROR) {
|
pr_err_ratelimited("ToPA ERROR encountered, trying to recover\n");
|
pt_topa_dump(buf);
|
status &= ~RTIT_STATUS_ERROR;
|
}
|
|
if (status & RTIT_STATUS_STOPPED) {
|
status &= ~RTIT_STATUS_STOPPED;
|
|
/*
|
* On systems that only do single-entry ToPA, hitting STOP
|
* means we are already losing data; need to let the decoder
|
* know.
|
*/
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries) ||
|
buf->output_off == sizes(TOPA_ENTRY(buf->cur, buf->cur_idx)->size)) {
|
perf_aux_output_flag(&pt->handle,
|
PERF_AUX_FLAG_TRUNCATED);
|
advance++;
|
}
|
}
|
|
/*
|
* Also on single-entry ToPA implementations, interrupt will come
|
* before the output reaches its output region's boundary.
|
*/
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries) && !buf->snapshot &&
|
pt_buffer_region_size(buf) - buf->output_off <= TOPA_PMI_MARGIN) {
|
void *head = pt_buffer_region(buf);
|
|
/* everything within this margin needs to be zeroed out */
|
memset(head + buf->output_off, 0,
|
pt_buffer_region_size(buf) -
|
buf->output_off);
|
advance++;
|
}
|
|
if (advance)
|
pt_buffer_advance(buf);
|
|
wrmsrl(MSR_IA32_RTIT_STATUS, status);
|
}
|
|
/**
|
* pt_read_offset() - translate registers into buffer pointers
|
* @buf: PT buffer.
|
*
|
* Set buffer's output pointers from MSR values.
|
*/
|
static void pt_read_offset(struct pt_buffer *buf)
|
{
|
u64 offset, base_topa;
|
|
rdmsrl(MSR_IA32_RTIT_OUTPUT_BASE, base_topa);
|
buf->cur = phys_to_virt(base_topa);
|
|
rdmsrl(MSR_IA32_RTIT_OUTPUT_MASK, offset);
|
/* offset within current output region */
|
buf->output_off = offset >> 32;
|
/* index of current output region within this table */
|
buf->cur_idx = (offset & 0xffffff80) >> 7;
|
}
|
|
/**
|
* pt_topa_next_entry() - obtain index of the first page in the next ToPA entry
|
* @buf: PT buffer.
|
* @pg: Page offset in the buffer.
|
*
|
* When advancing to the next output region (ToPA entry), given a page offset
|
* into the buffer, we need to find the offset of the first page in the next
|
* region.
|
*/
|
static unsigned int pt_topa_next_entry(struct pt_buffer *buf, unsigned int pg)
|
{
|
struct topa_entry *te = buf->topa_index[pg];
|
|
/* one region */
|
if (buf->first == buf->last && buf->first->last == 1)
|
return pg;
|
|
do {
|
pg++;
|
pg &= buf->nr_pages - 1;
|
} while (buf->topa_index[pg] == te);
|
|
return pg;
|
}
|
|
/**
|
* pt_buffer_reset_markers() - place interrupt and stop bits in the buffer
|
* @buf: PT buffer.
|
* @handle: Current output handle.
|
*
|
* Place INT and STOP marks to prevent overwriting old data that the consumer
|
* hasn't yet collected and waking up the consumer after a certain fraction of
|
* the buffer has filled up. Only needed and sensible for non-snapshot counters.
|
*
|
* This obviously relies on buf::head to figure out buffer markers, so it has
|
* to be called after pt_buffer_reset_offsets() and before the hardware tracing
|
* is enabled.
|
*/
|
static int pt_buffer_reset_markers(struct pt_buffer *buf,
|
struct perf_output_handle *handle)
|
|
{
|
unsigned long head = local64_read(&buf->head);
|
unsigned long idx, npages, wakeup;
|
|
/* can't stop in the middle of an output region */
|
if (buf->output_off + handle->size + 1 <
|
sizes(TOPA_ENTRY(buf->cur, buf->cur_idx)->size)) {
|
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
|
return -EINVAL;
|
}
|
|
|
/* single entry ToPA is handled by marking all regions STOP=1 INT=1 */
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries))
|
return 0;
|
|
/* clear STOP and INT from current entry */
|
buf->topa_index[buf->stop_pos]->stop = 0;
|
buf->topa_index[buf->stop_pos]->intr = 0;
|
buf->topa_index[buf->intr_pos]->intr = 0;
|
|
/* how many pages till the STOP marker */
|
npages = handle->size >> PAGE_SHIFT;
|
|
/* if it's on a page boundary, fill up one more page */
|
if (!offset_in_page(head + handle->size + 1))
|
npages++;
|
|
idx = (head >> PAGE_SHIFT) + npages;
|
idx &= buf->nr_pages - 1;
|
buf->stop_pos = idx;
|
|
wakeup = handle->wakeup >> PAGE_SHIFT;
|
|
/* in the worst case, wake up the consumer one page before hard stop */
|
idx = (head >> PAGE_SHIFT) + npages - 1;
|
if (idx > wakeup)
|
idx = wakeup;
|
|
idx &= buf->nr_pages - 1;
|
buf->intr_pos = idx;
|
|
buf->topa_index[buf->stop_pos]->stop = 1;
|
buf->topa_index[buf->stop_pos]->intr = 1;
|
buf->topa_index[buf->intr_pos]->intr = 1;
|
|
return 0;
|
}
|
|
/**
|
* pt_buffer_setup_topa_index() - build topa_index[] table of regions
|
* @buf: PT buffer.
|
*
|
* topa_index[] references output regions indexed by offset into the
|
* buffer for purposes of quick reverse lookup.
|
*/
|
static void pt_buffer_setup_topa_index(struct pt_buffer *buf)
|
{
|
struct topa *cur = buf->first, *prev = buf->last;
|
struct topa_entry *te_cur = TOPA_ENTRY(cur, 0),
|
*te_prev = TOPA_ENTRY(prev, prev->last - 1);
|
int pg = 0, idx = 0;
|
|
while (pg < buf->nr_pages) {
|
int tidx;
|
|
/* pages within one topa entry */
|
for (tidx = 0; tidx < 1 << te_cur->size; tidx++, pg++)
|
buf->topa_index[pg] = te_prev;
|
|
te_prev = te_cur;
|
|
if (idx == cur->last - 1) {
|
/* advance to next topa table */
|
idx = 0;
|
cur = list_entry(cur->list.next, struct topa, list);
|
} else {
|
idx++;
|
}
|
te_cur = TOPA_ENTRY(cur, idx);
|
}
|
|
}
|
|
/**
|
* pt_buffer_reset_offsets() - adjust buffer's write pointers from aux_head
|
* @buf: PT buffer.
|
* @head: Write pointer (aux_head) from AUX buffer.
|
*
|
* Find the ToPA table and entry corresponding to given @head and set buffer's
|
* "current" pointers accordingly. This is done after we have obtained the
|
* current aux_head position from a successful call to perf_aux_output_begin()
|
* to make sure the hardware is writing to the right place.
|
*
|
* This function modifies buf::{cur,cur_idx,output_off} that will be programmed
|
* into PT msrs when the tracing is enabled and buf::head and buf::data_size,
|
* which are used to determine INT and STOP markers' locations by a subsequent
|
* call to pt_buffer_reset_markers().
|
*/
|
static void pt_buffer_reset_offsets(struct pt_buffer *buf, unsigned long head)
|
{
|
int pg;
|
|
if (buf->snapshot)
|
head &= (buf->nr_pages << PAGE_SHIFT) - 1;
|
|
pg = (head >> PAGE_SHIFT) & (buf->nr_pages - 1);
|
pg = pt_topa_next_entry(buf, pg);
|
|
buf->cur = (struct topa *)((unsigned long)buf->topa_index[pg] & PAGE_MASK);
|
buf->cur_idx = ((unsigned long)buf->topa_index[pg] -
|
(unsigned long)buf->cur) / sizeof(struct topa_entry);
|
buf->output_off = head & (sizes(buf->cur->table[buf->cur_idx].size) - 1);
|
|
local64_set(&buf->head, head);
|
local_set(&buf->data_size, 0);
|
}
|
|
/**
|
* pt_buffer_fini_topa() - deallocate ToPA structure of a buffer
|
* @buf: PT buffer.
|
*/
|
static void pt_buffer_fini_topa(struct pt_buffer *buf)
|
{
|
struct topa *topa, *iter;
|
|
list_for_each_entry_safe(topa, iter, &buf->tables, list) {
|
/*
|
* right now, this is in free_aux() path only, so
|
* no need to unlink this table from the list
|
*/
|
topa_free(topa);
|
}
|
}
|
|
/**
|
* pt_buffer_init_topa() - initialize ToPA table for pt buffer
|
* @buf: PT buffer.
|
* @size: Total size of all regions within this ToPA.
|
* @gfp: Allocation flags.
|
*/
|
static int pt_buffer_init_topa(struct pt_buffer *buf, unsigned long nr_pages,
|
gfp_t gfp)
|
{
|
struct topa *topa;
|
int err;
|
|
topa = topa_alloc(buf->cpu, gfp);
|
if (!topa)
|
return -ENOMEM;
|
|
topa_insert_table(buf, topa);
|
|
while (buf->nr_pages < nr_pages) {
|
err = topa_insert_pages(buf, gfp);
|
if (err) {
|
pt_buffer_fini_topa(buf);
|
return -ENOMEM;
|
}
|
}
|
|
pt_buffer_setup_topa_index(buf);
|
|
/* link last table to the first one, unless we're double buffering */
|
if (pt_cap_get(PT_CAP_topa_multiple_entries)) {
|
TOPA_ENTRY(buf->last, -1)->base = buf->first->phys >> TOPA_SHIFT;
|
TOPA_ENTRY(buf->last, -1)->end = 1;
|
}
|
|
pt_topa_dump(buf);
|
return 0;
|
}
|
|
/**
|
* pt_buffer_setup_aux() - set up topa tables for a PT buffer
|
* @cpu: Cpu on which to allocate, -1 means current.
|
* @pages: Array of pointers to buffer pages passed from perf core.
|
* @nr_pages: Number of pages in the buffer.
|
* @snapshot: If this is a snapshot/overwrite counter.
|
*
|
* This is a pmu::setup_aux callback that sets up ToPA tables and all the
|
* bookkeeping for an AUX buffer.
|
*
|
* Return: Our private PT buffer structure.
|
*/
|
static void *
|
pt_buffer_setup_aux(struct perf_event *event, void **pages,
|
int nr_pages, bool snapshot)
|
{
|
struct pt_buffer *buf;
|
int node, ret, cpu = event->cpu;
|
|
if (!nr_pages)
|
return NULL;
|
|
if (cpu == -1)
|
cpu = raw_smp_processor_id();
|
node = cpu_to_node(cpu);
|
|
buf = kzalloc_node(offsetof(struct pt_buffer, topa_index[nr_pages]),
|
GFP_KERNEL, node);
|
if (!buf)
|
return NULL;
|
|
buf->cpu = cpu;
|
buf->snapshot = snapshot;
|
buf->data_pages = pages;
|
|
INIT_LIST_HEAD(&buf->tables);
|
|
ret = pt_buffer_init_topa(buf, nr_pages, GFP_KERNEL);
|
if (ret) {
|
kfree(buf);
|
return NULL;
|
}
|
|
return buf;
|
}
|
|
/**
|
* pt_buffer_free_aux() - perf AUX deallocation path callback
|
* @data: PT buffer.
|
*/
|
static void pt_buffer_free_aux(void *data)
|
{
|
struct pt_buffer *buf = data;
|
|
pt_buffer_fini_topa(buf);
|
kfree(buf);
|
}
|
|
static int pt_addr_filters_init(struct perf_event *event)
|
{
|
struct pt_filters *filters;
|
int node = event->cpu == -1 ? -1 : cpu_to_node(event->cpu);
|
|
if (!pt_cap_get(PT_CAP_num_address_ranges))
|
return 0;
|
|
filters = kzalloc_node(sizeof(struct pt_filters), GFP_KERNEL, node);
|
if (!filters)
|
return -ENOMEM;
|
|
if (event->parent)
|
memcpy(filters, event->parent->hw.addr_filters,
|
sizeof(*filters));
|
|
event->hw.addr_filters = filters;
|
|
return 0;
|
}
|
|
static void pt_addr_filters_fini(struct perf_event *event)
|
{
|
kfree(event->hw.addr_filters);
|
event->hw.addr_filters = NULL;
|
}
|
|
static inline bool valid_kernel_ip(unsigned long ip)
|
{
|
return virt_addr_valid(ip) && kernel_ip(ip);
|
}
|
|
static int pt_event_addr_filters_validate(struct list_head *filters)
|
{
|
struct perf_addr_filter *filter;
|
int range = 0;
|
|
list_for_each_entry(filter, filters, entry) {
|
/*
|
* PT doesn't support single address triggers and
|
* 'start' filters.
|
*/
|
if (!filter->size ||
|
filter->action == PERF_ADDR_FILTER_ACTION_START)
|
return -EOPNOTSUPP;
|
|
if (!filter->path.dentry) {
|
if (!valid_kernel_ip(filter->offset))
|
return -EINVAL;
|
|
if (!valid_kernel_ip(filter->offset + filter->size))
|
return -EINVAL;
|
}
|
|
if (++range > pt_cap_get(PT_CAP_num_address_ranges))
|
return -EOPNOTSUPP;
|
}
|
|
return 0;
|
}
|
|
static void pt_event_addr_filters_sync(struct perf_event *event)
|
{
|
struct perf_addr_filters_head *head = perf_event_addr_filters(event);
|
unsigned long msr_a, msr_b;
|
struct perf_addr_filter_range *fr = event->addr_filter_ranges;
|
struct pt_filters *filters = event->hw.addr_filters;
|
struct perf_addr_filter *filter;
|
int range = 0;
|
|
if (!filters)
|
return;
|
|
list_for_each_entry(filter, &head->list, entry) {
|
if (filter->path.dentry && !fr[range].start) {
|
msr_a = msr_b = 0;
|
} else {
|
/* apply the offset */
|
msr_a = fr[range].start;
|
msr_b = msr_a + fr[range].size - 1;
|
}
|
|
filters->filter[range].msr_a = msr_a;
|
filters->filter[range].msr_b = msr_b;
|
if (filter->action == PERF_ADDR_FILTER_ACTION_FILTER)
|
filters->filter[range].config = 1;
|
else
|
filters->filter[range].config = 2;
|
range++;
|
}
|
|
filters->nr_filters = range;
|
}
|
|
/**
|
* intel_pt_interrupt() - PT PMI handler
|
*/
|
void intel_pt_interrupt(void)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
struct pt_buffer *buf;
|
struct perf_event *event = pt->handle.event;
|
|
/*
|
* There may be a dangling PT bit in the interrupt status register
|
* after PT has been disabled by pt_event_stop(). Make sure we don't
|
* do anything (particularly, re-enable) for this event here.
|
*/
|
if (!READ_ONCE(pt->handle_nmi))
|
return;
|
|
if (!event)
|
return;
|
|
pt_config_stop(event);
|
|
buf = perf_get_aux(&pt->handle);
|
if (!buf)
|
return;
|
|
pt_read_offset(buf);
|
|
pt_handle_status(pt);
|
|
pt_update_head(pt);
|
|
perf_aux_output_end(&pt->handle, local_xchg(&buf->data_size, 0));
|
|
if (!event->hw.state) {
|
int ret;
|
|
buf = perf_aux_output_begin(&pt->handle, event);
|
if (!buf) {
|
event->hw.state = PERF_HES_STOPPED;
|
return;
|
}
|
|
pt_buffer_reset_offsets(buf, pt->handle.head);
|
/* snapshot counters don't use PMI, so it's safe */
|
ret = pt_buffer_reset_markers(buf, &pt->handle);
|
if (ret) {
|
perf_aux_output_end(&pt->handle, 0);
|
return;
|
}
|
|
pt_config_buffer(buf->cur->table, buf->cur_idx,
|
buf->output_off);
|
pt_config(event);
|
}
|
}
|
|
void intel_pt_handle_vmx(int on)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
struct perf_event *event;
|
unsigned long flags;
|
|
/* PT plays nice with VMX, do nothing */
|
if (pt_pmu.vmx)
|
return;
|
|
/*
|
* VMXON will clear RTIT_CTL.TraceEn; we need to make
|
* sure to not try to set it while VMX is on. Disable
|
* interrupts to avoid racing with pmu callbacks;
|
* concurrent PMI should be handled fine.
|
*/
|
local_irq_save(flags);
|
WRITE_ONCE(pt->vmx_on, on);
|
|
/*
|
* If an AUX transaction is in progress, it will contain
|
* gap(s), so flag it PARTIAL to inform the user.
|
*/
|
event = pt->handle.event;
|
if (event)
|
perf_aux_output_flag(&pt->handle,
|
PERF_AUX_FLAG_PARTIAL);
|
|
/* Turn PTs back on */
|
if (!on && event)
|
wrmsrl(MSR_IA32_RTIT_CTL, event->hw.config);
|
|
local_irq_restore(flags);
|
}
|
EXPORT_SYMBOL_GPL(intel_pt_handle_vmx);
|
|
/*
|
* PMU callbacks
|
*/
|
|
static void pt_event_start(struct perf_event *event, int mode)
|
{
|
struct hw_perf_event *hwc = &event->hw;
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
struct pt_buffer *buf;
|
|
buf = perf_aux_output_begin(&pt->handle, event);
|
if (!buf)
|
goto fail_stop;
|
|
pt_buffer_reset_offsets(buf, pt->handle.head);
|
if (!buf->snapshot) {
|
if (pt_buffer_reset_markers(buf, &pt->handle))
|
goto fail_end_stop;
|
}
|
|
WRITE_ONCE(pt->handle_nmi, 1);
|
hwc->state = 0;
|
|
pt_config_buffer(buf->cur->table, buf->cur_idx,
|
buf->output_off);
|
pt_config(event);
|
|
return;
|
|
fail_end_stop:
|
perf_aux_output_end(&pt->handle, 0);
|
fail_stop:
|
hwc->state = PERF_HES_STOPPED;
|
}
|
|
static void pt_event_stop(struct perf_event *event, int mode)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
|
/*
|
* Protect against the PMI racing with disabling wrmsr,
|
* see comment in intel_pt_interrupt().
|
*/
|
WRITE_ONCE(pt->handle_nmi, 0);
|
|
pt_config_stop(event);
|
|
if (event->hw.state == PERF_HES_STOPPED)
|
return;
|
|
event->hw.state = PERF_HES_STOPPED;
|
|
if (mode & PERF_EF_UPDATE) {
|
struct pt_buffer *buf = perf_get_aux(&pt->handle);
|
|
if (!buf)
|
return;
|
|
if (WARN_ON_ONCE(pt->handle.event != event))
|
return;
|
|
pt_read_offset(buf);
|
|
pt_handle_status(pt);
|
|
pt_update_head(pt);
|
|
if (buf->snapshot)
|
pt->handle.head =
|
local_xchg(&buf->data_size,
|
buf->nr_pages << PAGE_SHIFT);
|
perf_aux_output_end(&pt->handle, local_xchg(&buf->data_size, 0));
|
}
|
}
|
|
static void pt_event_del(struct perf_event *event, int mode)
|
{
|
pt_event_stop(event, PERF_EF_UPDATE);
|
}
|
|
static int pt_event_add(struct perf_event *event, int mode)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
struct hw_perf_event *hwc = &event->hw;
|
int ret = -EBUSY;
|
|
if (pt->handle.event)
|
goto fail;
|
|
if (mode & PERF_EF_START) {
|
pt_event_start(event, 0);
|
ret = -EINVAL;
|
if (hwc->state == PERF_HES_STOPPED)
|
goto fail;
|
} else {
|
hwc->state = PERF_HES_STOPPED;
|
}
|
|
ret = 0;
|
fail:
|
|
return ret;
|
}
|
|
static void pt_event_read(struct perf_event *event)
|
{
|
}
|
|
static void pt_event_destroy(struct perf_event *event)
|
{
|
pt_addr_filters_fini(event);
|
x86_del_exclusive(x86_lbr_exclusive_pt);
|
}
|
|
static int pt_event_init(struct perf_event *event)
|
{
|
if (event->attr.type != pt_pmu.pmu.type)
|
return -ENOENT;
|
|
if (!pt_event_valid(event))
|
return -EINVAL;
|
|
if (x86_add_exclusive(x86_lbr_exclusive_pt))
|
return -EBUSY;
|
|
if (pt_addr_filters_init(event)) {
|
x86_del_exclusive(x86_lbr_exclusive_pt);
|
return -ENOMEM;
|
}
|
|
event->destroy = pt_event_destroy;
|
|
return 0;
|
}
|
|
void cpu_emergency_stop_pt(void)
|
{
|
struct pt *pt = this_cpu_ptr(&pt_ctx);
|
|
if (pt->handle.event)
|
pt_event_stop(pt->handle.event, PERF_EF_UPDATE);
|
}
|
|
static __init int pt_init(void)
|
{
|
int ret, cpu, prior_warn = 0;
|
|
BUILD_BUG_ON(sizeof(struct topa) > PAGE_SIZE);
|
|
if (!boot_cpu_has(X86_FEATURE_INTEL_PT))
|
return -ENODEV;
|
|
get_online_cpus();
|
for_each_online_cpu(cpu) {
|
u64 ctl;
|
|
ret = rdmsrl_safe_on_cpu(cpu, MSR_IA32_RTIT_CTL, &ctl);
|
if (!ret && (ctl & RTIT_CTL_TRACEEN))
|
prior_warn++;
|
}
|
put_online_cpus();
|
|
if (prior_warn) {
|
x86_add_exclusive(x86_lbr_exclusive_pt);
|
pr_warn("PT is enabled at boot time, doing nothing\n");
|
|
return -EBUSY;
|
}
|
|
ret = pt_pmu_hw_init();
|
if (ret)
|
return ret;
|
|
if (!pt_cap_get(PT_CAP_topa_output)) {
|
pr_warn("ToPA output is not supported on this CPU\n");
|
return -ENODEV;
|
}
|
|
if (!pt_cap_get(PT_CAP_topa_multiple_entries))
|
pt_pmu.pmu.capabilities =
|
PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_AUX_SW_DOUBLEBUF;
|
|
pt_pmu.pmu.capabilities |= PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE;
|
pt_pmu.pmu.attr_groups = pt_attr_groups;
|
pt_pmu.pmu.task_ctx_nr = perf_sw_context;
|
pt_pmu.pmu.event_init = pt_event_init;
|
pt_pmu.pmu.add = pt_event_add;
|
pt_pmu.pmu.del = pt_event_del;
|
pt_pmu.pmu.start = pt_event_start;
|
pt_pmu.pmu.stop = pt_event_stop;
|
pt_pmu.pmu.read = pt_event_read;
|
pt_pmu.pmu.setup_aux = pt_buffer_setup_aux;
|
pt_pmu.pmu.free_aux = pt_buffer_free_aux;
|
pt_pmu.pmu.addr_filters_sync = pt_event_addr_filters_sync;
|
pt_pmu.pmu.addr_filters_validate = pt_event_addr_filters_validate;
|
pt_pmu.pmu.nr_addr_filters =
|
pt_cap_get(PT_CAP_num_address_ranges);
|
|
ret = perf_pmu_register(&pt_pmu.pmu, "intel_pt", -1);
|
|
return ret;
|
}
|
arch_initcall(pt_init);
|
