| /* |
| * Performance events - AMD IBS |
| * |
| * Copyright (C) 2011 Advanced Micro Devices, Inc., Robert Richter |
| * |
| * For licencing details see kernel-base/COPYING |
| */ |
| |
| #include <linux/perf_event.h> |
| #include <linux/module.h> |
| #include <linux/pci.h> |
| #include <linux/ptrace.h> |
| #include <linux/syscore_ops.h> |
| |
| #include <asm/apic.h> |
| |
| #include "../perf_event.h" |
| |
| static u32 ibs_caps; |
| |
| #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) |
| |
| #include <linux/kprobes.h> |
| #include <linux/hardirq.h> |
| |
| #include <asm/nmi.h> |
| |
| #define IBS_FETCH_CONFIG_MASK (IBS_FETCH_RAND_EN | IBS_FETCH_MAX_CNT) |
| #define IBS_OP_CONFIG_MASK IBS_OP_MAX_CNT |
| |
| enum ibs_states { |
| IBS_ENABLED = 0, |
| IBS_STARTED = 1, |
| IBS_STOPPING = 2, |
| |
| IBS_MAX_STATES, |
| }; |
| |
| struct cpu_perf_ibs { |
| struct perf_event *event; |
| unsigned long state[BITS_TO_LONGS(IBS_MAX_STATES)]; |
| }; |
| |
| struct perf_ibs { |
| struct pmu pmu; |
| unsigned int msr; |
| u64 config_mask; |
| u64 cnt_mask; |
| u64 enable_mask; |
| u64 valid_mask; |
| u64 max_period; |
| unsigned long offset_mask[1]; |
| int offset_max; |
| struct cpu_perf_ibs __percpu *pcpu; |
| |
| struct attribute **format_attrs; |
| struct attribute_group format_group; |
| const struct attribute_group *attr_groups[2]; |
| |
| u64 (*get_count)(u64 config); |
| }; |
| |
| struct perf_ibs_data { |
| u32 size; |
| union { |
| u32 data[0]; /* data buffer starts here */ |
| u32 caps; |
| }; |
| u64 regs[MSR_AMD64_IBS_REG_COUNT_MAX]; |
| }; |
| |
| static int |
| perf_event_set_period(struct hw_perf_event *hwc, u64 min, u64 max, u64 *hw_period) |
| { |
| s64 left = local64_read(&hwc->period_left); |
| s64 period = hwc->sample_period; |
| int overflow = 0; |
| |
| /* |
| * If we are way outside a reasonable range then just skip forward: |
| */ |
| if (unlikely(left <= -period)) { |
| left = period; |
| local64_set(&hwc->period_left, left); |
| hwc->last_period = period; |
| overflow = 1; |
| } |
| |
| if (unlikely(left < (s64)min)) { |
| left += period; |
| local64_set(&hwc->period_left, left); |
| hwc->last_period = period; |
| overflow = 1; |
| } |
| |
| /* |
| * If the hw period that triggers the sw overflow is too short |
| * we might hit the irq handler. This biases the results. |
| * Thus we shorten the next-to-last period and set the last |
| * period to the max period. |
| */ |
| if (left > max) { |
| left -= max; |
| if (left > max) |
| left = max; |
| else if (left < min) |
| left = min; |
| } |
| |
| *hw_period = (u64)left; |
| |
| return overflow; |
| } |
| |
| static int |
| perf_event_try_update(struct perf_event *event, u64 new_raw_count, int width) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| int shift = 64 - width; |
| u64 prev_raw_count; |
| u64 delta; |
| |
| /* |
| * Careful: an NMI might modify the previous event value. |
| * |
| * Our tactic to handle this is to first atomically read and |
| * exchange a new raw count - then add that new-prev delta |
| * count to the generic event atomically: |
| */ |
| prev_raw_count = local64_read(&hwc->prev_count); |
| if (local64_cmpxchg(&hwc->prev_count, prev_raw_count, |
| new_raw_count) != prev_raw_count) |
| return 0; |
| |
| /* |
| * Now we have the new raw value and have updated the prev |
| * timestamp already. We can now calculate the elapsed delta |
| * (event-)time and add that to the generic event. |
| * |
| * Careful, not all hw sign-extends above the physical width |
| * of the count. |
| */ |
| delta = (new_raw_count << shift) - (prev_raw_count << shift); |
| delta >>= shift; |
| |
| local64_add(delta, &event->count); |
| local64_sub(delta, &hwc->period_left); |
| |
| return 1; |
| } |
| |
| static struct perf_ibs perf_ibs_fetch; |
| static struct perf_ibs perf_ibs_op; |
| |
| static struct perf_ibs *get_ibs_pmu(int type) |
| { |
| if (perf_ibs_fetch.pmu.type == type) |
| return &perf_ibs_fetch; |
| if (perf_ibs_op.pmu.type == type) |
| return &perf_ibs_op; |
| return NULL; |
| } |
| |
| /* |
| * Use IBS for precise event sampling: |
| * |
| * perf record -a -e cpu-cycles:p ... # use ibs op counting cycle count |
| * perf record -a -e r076:p ... # same as -e cpu-cycles:p |
| * perf record -a -e r0C1:p ... # use ibs op counting micro-ops |
| * |
| * IbsOpCntCtl (bit 19) of IBS Execution Control Register (IbsOpCtl, |
| * MSRC001_1033) is used to select either cycle or micro-ops counting |
| * mode. |
| * |
| * The rip of IBS samples has skid 0. Thus, IBS supports precise |
| * levels 1 and 2 and the PERF_EFLAGS_EXACT is set. In rare cases the |
| * rip is invalid when IBS was not able to record the rip correctly. |
| * We clear PERF_EFLAGS_EXACT and take the rip from pt_regs then. |
| * |
| */ |
| static int perf_ibs_precise_event(struct perf_event *event, u64 *config) |
| { |
| switch (event->attr.precise_ip) { |
| case 0: |
| return -ENOENT; |
| case 1: |
| case 2: |
| break; |
| default: |
| return -EOPNOTSUPP; |
| } |
| |
| switch (event->attr.type) { |
| case PERF_TYPE_HARDWARE: |
| switch (event->attr.config) { |
| case PERF_COUNT_HW_CPU_CYCLES: |
| *config = 0; |
| return 0; |
| } |
| break; |
| case PERF_TYPE_RAW: |
| switch (event->attr.config) { |
| case 0x0076: |
| *config = 0; |
| return 0; |
| case 0x00C1: |
| *config = IBS_OP_CNT_CTL; |
| return 0; |
| } |
| break; |
| default: |
| return -ENOENT; |
| } |
| |
| return -EOPNOTSUPP; |
| } |
| |
| static const struct perf_event_attr ibs_notsupp = { |
| .exclude_user = 1, |
| .exclude_kernel = 1, |
| .exclude_hv = 1, |
| .exclude_idle = 1, |
| .exclude_host = 1, |
| .exclude_guest = 1, |
| }; |
| |
| static int perf_ibs_init(struct perf_event *event) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| struct perf_ibs *perf_ibs; |
| u64 max_cnt, config; |
| int ret; |
| |
| perf_ibs = get_ibs_pmu(event->attr.type); |
| if (perf_ibs) { |
| config = event->attr.config; |
| } else { |
| perf_ibs = &perf_ibs_op; |
| ret = perf_ibs_precise_event(event, &config); |
| if (ret) |
| return ret; |
| } |
| |
| if (event->pmu != &perf_ibs->pmu) |
| return -ENOENT; |
| |
| if (perf_flags(&event->attr) & perf_flags(&ibs_notsupp)) |
| return -EINVAL; |
| |
| if (config & ~perf_ibs->config_mask) |
| return -EINVAL; |
| |
| if (hwc->sample_period) { |
| if (config & perf_ibs->cnt_mask) |
| /* raw max_cnt may not be set */ |
| return -EINVAL; |
| if (!event->attr.sample_freq && hwc->sample_period & 0x0f) |
| /* |
| * lower 4 bits can not be set in ibs max cnt, |
| * but allowing it in case we adjust the |
| * sample period to set a frequency. |
| */ |
| return -EINVAL; |
| hwc->sample_period &= ~0x0FULL; |
| if (!hwc->sample_period) |
| hwc->sample_period = 0x10; |
| } else { |
| max_cnt = config & perf_ibs->cnt_mask; |
| config &= ~perf_ibs->cnt_mask; |
| event->attr.sample_period = max_cnt << 4; |
| hwc->sample_period = event->attr.sample_period; |
| } |
| |
| if (!hwc->sample_period) |
| return -EINVAL; |
| |
| /* |
| * If we modify hwc->sample_period, we also need to update |
| * hwc->last_period and hwc->period_left. |
| */ |
| hwc->last_period = hwc->sample_period; |
| local64_set(&hwc->period_left, hwc->sample_period); |
| |
| hwc->config_base = perf_ibs->msr; |
| hwc->config = config; |
| |
| return 0; |
| } |
| |
| static int perf_ibs_set_period(struct perf_ibs *perf_ibs, |
| struct hw_perf_event *hwc, u64 *period) |
| { |
| int overflow; |
| |
| /* ignore lower 4 bits in min count: */ |
| overflow = perf_event_set_period(hwc, 1<<4, perf_ibs->max_period, period); |
| local64_set(&hwc->prev_count, 0); |
| |
| return overflow; |
| } |
| |
| static u64 get_ibs_fetch_count(u64 config) |
| { |
| return (config & IBS_FETCH_CNT) >> 12; |
| } |
| |
| static u64 get_ibs_op_count(u64 config) |
| { |
| u64 count = 0; |
| |
| if (config & IBS_OP_VAL) |
| count += (config & IBS_OP_MAX_CNT) << 4; /* cnt rolled over */ |
| |
| if (ibs_caps & IBS_CAPS_RDWROPCNT) |
| count += (config & IBS_OP_CUR_CNT) >> 32; |
| |
| return count; |
| } |
| |
| static void |
| perf_ibs_event_update(struct perf_ibs *perf_ibs, struct perf_event *event, |
| u64 *config) |
| { |
| u64 count = perf_ibs->get_count(*config); |
| |
| /* |
| * Set width to 64 since we do not overflow on max width but |
| * instead on max count. In perf_ibs_set_period() we clear |
| * prev count manually on overflow. |
| */ |
| while (!perf_event_try_update(event, count, 64)) { |
| rdmsrl(event->hw.config_base, *config); |
| count = perf_ibs->get_count(*config); |
| } |
| } |
| |
| static inline void perf_ibs_enable_event(struct perf_ibs *perf_ibs, |
| struct hw_perf_event *hwc, u64 config) |
| { |
| wrmsrl(hwc->config_base, hwc->config | config | perf_ibs->enable_mask); |
| } |
| |
| /* |
| * Erratum #420 Instruction-Based Sampling Engine May Generate |
| * Interrupt that Cannot Be Cleared: |
| * |
| * Must clear counter mask first, then clear the enable bit. See |
| * Revision Guide for AMD Family 10h Processors, Publication #41322. |
| */ |
| static inline void perf_ibs_disable_event(struct perf_ibs *perf_ibs, |
| struct hw_perf_event *hwc, u64 config) |
| { |
| config &= ~perf_ibs->cnt_mask; |
| wrmsrl(hwc->config_base, config); |
| config &= ~perf_ibs->enable_mask; |
| wrmsrl(hwc->config_base, config); |
| } |
| |
| /* |
| * We cannot restore the ibs pmu state, so we always needs to update |
| * the event while stopping it and then reset the state when starting |
| * again. Thus, ignoring PERF_EF_RELOAD and PERF_EF_UPDATE flags in |
| * perf_ibs_start()/perf_ibs_stop() and instead always do it. |
| */ |
| static void perf_ibs_start(struct perf_event *event, int flags) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu); |
| struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu); |
| u64 period; |
| |
| if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED))) |
| return; |
| |
| WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE)); |
| hwc->state = 0; |
| |
| perf_ibs_set_period(perf_ibs, hwc, &period); |
| /* |
| * Set STARTED before enabling the hardware, such that |
| * a subsequent NMI must observe it. Then clear STOPPING |
| * such that we don't consume NMIs by accident. |
| */ |
| set_bit(IBS_STARTED, pcpu->state); |
| clear_bit(IBS_STOPPING, pcpu->state); |
| perf_ibs_enable_event(perf_ibs, hwc, period >> 4); |
| |
| perf_event_update_userpage(event); |
| } |
| |
| static void perf_ibs_stop(struct perf_event *event, int flags) |
| { |
| struct hw_perf_event *hwc = &event->hw; |
| struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu); |
| struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu); |
| u64 config; |
| int stopping; |
| |
| stopping = test_bit(IBS_STARTED, pcpu->state); |
| |
| if (!stopping && (hwc->state & PERF_HES_UPTODATE)) |
| return; |
| |
| rdmsrl(hwc->config_base, config); |
| |
| if (stopping) { |
| /* |
| * Set STOPPING before disabling the hardware, such that it |
| * must be visible to NMIs the moment we clear the EN bit, |
| * at which point we can generate an !VALID sample which |
| * we need to consume. |
| */ |
| set_bit(IBS_STOPPING, pcpu->state); |
| perf_ibs_disable_event(perf_ibs, hwc, config); |
| /* |
| * Clear STARTED after disabling the hardware; if it were |
| * cleared before an NMI hitting after the clear but before |
| * clearing the EN bit might think it a spurious NMI and not |
| * handle it. |
| * |
| * Clearing it after, however, creates the problem of the NMI |
| * handler seeing STARTED but not having a valid sample. |
| */ |
| clear_bit(IBS_STARTED, pcpu->state); |
| WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED); |
| hwc->state |= PERF_HES_STOPPED; |
| } |
| |
| if (hwc->state & PERF_HES_UPTODATE) |
| return; |
| |
| /* |
| * Clear valid bit to not count rollovers on update, rollovers |
| * are only updated in the irq handler. |
| */ |
| config &= ~perf_ibs->valid_mask; |
| |
| perf_ibs_event_update(perf_ibs, event, &config); |
| hwc->state |= PERF_HES_UPTODATE; |
| } |
| |
| static int perf_ibs_add(struct perf_event *event, int flags) |
| { |
| struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu); |
| struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu); |
| |
| if (test_and_set_bit(IBS_ENABLED, pcpu->state)) |
| return -ENOSPC; |
| |
| event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED; |
| |
| pcpu->event = event; |
| |
| if (flags & PERF_EF_START) |
| perf_ibs_start(event, PERF_EF_RELOAD); |
| |
| return 0; |
| } |
| |
| static void perf_ibs_del(struct perf_event *event, int flags) |
| { |
| struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu); |
| struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu); |
| |
| if (!test_and_clear_bit(IBS_ENABLED, pcpu->state)) |
| return; |
| |
| perf_ibs_stop(event, PERF_EF_UPDATE); |
| |
| pcpu->event = NULL; |
| |
| perf_event_update_userpage(event); |
| } |
| |
| static void perf_ibs_read(struct perf_event *event) { } |
| |
| PMU_FORMAT_ATTR(rand_en, "config:57"); |
| PMU_FORMAT_ATTR(cnt_ctl, "config:19"); |
| |
| static struct attribute *ibs_fetch_format_attrs[] = { |
| &format_attr_rand_en.attr, |
| NULL, |
| }; |
| |
| static struct attribute *ibs_op_format_attrs[] = { |
| NULL, /* &format_attr_cnt_ctl.attr if IBS_CAPS_OPCNT */ |
| NULL, |
| }; |
| |
| static struct perf_ibs perf_ibs_fetch = { |
| .pmu = { |
| .task_ctx_nr = perf_invalid_context, |
| |
| .event_init = perf_ibs_init, |
| .add = perf_ibs_add, |
| .del = perf_ibs_del, |
| .start = perf_ibs_start, |
| .stop = perf_ibs_stop, |
| .read = perf_ibs_read, |
| }, |
| .msr = MSR_AMD64_IBSFETCHCTL, |
| .config_mask = IBS_FETCH_CONFIG_MASK, |
| .cnt_mask = IBS_FETCH_MAX_CNT, |
| .enable_mask = IBS_FETCH_ENABLE, |
| .valid_mask = IBS_FETCH_VAL, |
| .max_period = IBS_FETCH_MAX_CNT << 4, |
| .offset_mask = { MSR_AMD64_IBSFETCH_REG_MASK }, |
| .offset_max = MSR_AMD64_IBSFETCH_REG_COUNT, |
| .format_attrs = ibs_fetch_format_attrs, |
| |
| .get_count = get_ibs_fetch_count, |
| }; |
| |
| static struct perf_ibs perf_ibs_op = { |
| .pmu = { |
| .task_ctx_nr = perf_invalid_context, |
| |
| .event_init = perf_ibs_init, |
| .add = perf_ibs_add, |
| .del = perf_ibs_del, |
| .start = perf_ibs_start, |
| .stop = perf_ibs_stop, |
| .read = perf_ibs_read, |
| }, |
| .msr = MSR_AMD64_IBSOPCTL, |
| .config_mask = IBS_OP_CONFIG_MASK, |
| .cnt_mask = IBS_OP_MAX_CNT, |
| .enable_mask = IBS_OP_ENABLE, |
| .valid_mask = IBS_OP_VAL, |
| .max_period = IBS_OP_MAX_CNT << 4, |
| .offset_mask = { MSR_AMD64_IBSOP_REG_MASK }, |
| .offset_max = MSR_AMD64_IBSOP_REG_COUNT, |
| .format_attrs = ibs_op_format_attrs, |
| |
| .get_count = get_ibs_op_count, |
| }; |
| |
| static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs) |
| { |
| struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu); |
| struct perf_event *event = pcpu->event; |
| struct hw_perf_event *hwc = &event->hw; |
| struct perf_sample_data data; |
| struct perf_raw_record raw; |
| struct pt_regs regs; |
| struct perf_ibs_data ibs_data; |
| int offset, size, check_rip, offset_max, throttle = 0; |
| unsigned int msr; |
| u64 *buf, *config, period; |
| |
| if (!test_bit(IBS_STARTED, pcpu->state)) { |
| fail: |
| /* |
| * Catch spurious interrupts after stopping IBS: After |
| * disabling IBS there could be still incoming NMIs |
| * with samples that even have the valid bit cleared. |
| * Mark all this NMIs as handled. |
| */ |
| if (test_and_clear_bit(IBS_STOPPING, pcpu->state)) |
| return 1; |
| |
| return 0; |
| } |
| |
| msr = hwc->config_base; |
| buf = ibs_data.regs; |
| rdmsrl(msr, *buf); |
| if (!(*buf++ & perf_ibs->valid_mask)) |
| goto fail; |
| |
| config = &ibs_data.regs[0]; |
| perf_ibs_event_update(perf_ibs, event, config); |
| perf_sample_data_init(&data, 0, hwc->last_period); |
| if (!perf_ibs_set_period(perf_ibs, hwc, &period)) |
| goto out; /* no sw counter overflow */ |
| |
| ibs_data.caps = ibs_caps; |
| size = 1; |
| offset = 1; |
| check_rip = (perf_ibs == &perf_ibs_op && (ibs_caps & IBS_CAPS_RIPINVALIDCHK)); |
| if (event->attr.sample_type & PERF_SAMPLE_RAW) |
| offset_max = perf_ibs->offset_max; |
| else if (check_rip) |
| offset_max = 2; |
| else |
| offset_max = 1; |
| do { |
| rdmsrl(msr + offset, *buf++); |
| size++; |
| offset = find_next_bit(perf_ibs->offset_mask, |
| perf_ibs->offset_max, |
| offset + 1); |
| } while (offset < offset_max); |
| if (event->attr.sample_type & PERF_SAMPLE_RAW) { |
| /* |
| * Read IbsBrTarget and IbsOpData4 separately |
| * depending on their availability. |
| * Can't add to offset_max as they are staggered |
| */ |
| if (ibs_caps & IBS_CAPS_BRNTRGT) { |
| rdmsrl(MSR_AMD64_IBSBRTARGET, *buf++); |
| size++; |
| } |
| if (ibs_caps & IBS_CAPS_OPDATA4) { |
| rdmsrl(MSR_AMD64_IBSOPDATA4, *buf++); |
| size++; |
| } |
| } |
| ibs_data.size = sizeof(u64) * size; |
| |
| regs = *iregs; |
| if (check_rip && (ibs_data.regs[2] & IBS_RIP_INVALID)) { |
| regs.flags &= ~PERF_EFLAGS_EXACT; |
| } else { |
| set_linear_ip(®s, ibs_data.regs[1]); |
| regs.flags |= PERF_EFLAGS_EXACT; |
| } |
| |
| if (event->attr.sample_type & PERF_SAMPLE_RAW) { |
| raw.size = sizeof(u32) + ibs_data.size; |
| raw.data = ibs_data.data; |
| data.raw = &raw; |
| } |
| |
| throttle = perf_event_overflow(event, &data, ®s); |
| out: |
| if (throttle) |
| perf_ibs_stop(event, 0); |
| else |
| perf_ibs_enable_event(perf_ibs, hwc, period >> 4); |
| |
| perf_event_update_userpage(event); |
| |
| return 1; |
| } |
| |
| static int |
| perf_ibs_nmi_handler(unsigned int cmd, struct pt_regs *regs) |
| { |
| u64 stamp = sched_clock(); |
| int handled = 0; |
| |
| handled += perf_ibs_handle_irq(&perf_ibs_fetch, regs); |
| handled += perf_ibs_handle_irq(&perf_ibs_op, regs); |
| |
| if (handled) |
| inc_irq_stat(apic_perf_irqs); |
| |
| perf_sample_event_took(sched_clock() - stamp); |
| |
| return handled; |
| } |
| NOKPROBE_SYMBOL(perf_ibs_nmi_handler); |
| |
| static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name) |
| { |
| struct cpu_perf_ibs __percpu *pcpu; |
| int ret; |
| |
| pcpu = alloc_percpu(struct cpu_perf_ibs); |
| if (!pcpu) |
| return -ENOMEM; |
| |
| perf_ibs->pcpu = pcpu; |
| |
| /* register attributes */ |
| if (perf_ibs->format_attrs[0]) { |
| memset(&perf_ibs->format_group, 0, sizeof(perf_ibs->format_group)); |
| perf_ibs->format_group.name = "format"; |
| perf_ibs->format_group.attrs = perf_ibs->format_attrs; |
| |
| memset(&perf_ibs->attr_groups, 0, sizeof(perf_ibs->attr_groups)); |
| perf_ibs->attr_groups[0] = &perf_ibs->format_group; |
| perf_ibs->pmu.attr_groups = perf_ibs->attr_groups; |
| } |
| |
| ret = perf_pmu_register(&perf_ibs->pmu, name, -1); |
| if (ret) { |
| perf_ibs->pcpu = NULL; |
| free_percpu(pcpu); |
| } |
| |
| return ret; |
| } |
| |
| static __init int perf_event_ibs_init(void) |
| { |
| struct attribute **attr = ibs_op_format_attrs; |
| |
| if (!ibs_caps) |
| return -ENODEV; /* ibs not supported by the cpu */ |
| |
| perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch"); |
| |
| if (ibs_caps & IBS_CAPS_OPCNT) { |
| perf_ibs_op.config_mask |= IBS_OP_CNT_CTL; |
| *attr++ = &format_attr_cnt_ctl.attr; |
| } |
| perf_ibs_pmu_init(&perf_ibs_op, "ibs_op"); |
| |
| register_nmi_handler(NMI_LOCAL, perf_ibs_nmi_handler, 0, "perf_ibs"); |
| pr_info("perf: AMD IBS detected (0x%08x)\n", ibs_caps); |
| |
| return 0; |
| } |
| |
| #else /* defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) */ |
| |
| static __init int perf_event_ibs_init(void) { return 0; } |
| |
| #endif |
| |
| /* IBS - apic initialization, for perf and oprofile */ |
| |
| static __init u32 __get_ibs_caps(void) |
| { |
| u32 caps; |
| unsigned int max_level; |
| |
| if (!boot_cpu_has(X86_FEATURE_IBS)) |
| return 0; |
| |
| /* check IBS cpuid feature flags */ |
| max_level = cpuid_eax(0x80000000); |
| if (max_level < IBS_CPUID_FEATURES) |
| return IBS_CAPS_DEFAULT; |
| |
| caps = cpuid_eax(IBS_CPUID_FEATURES); |
| if (!(caps & IBS_CAPS_AVAIL)) |
| /* cpuid flags not valid */ |
| return IBS_CAPS_DEFAULT; |
| |
| return caps; |
| } |
| |
| u32 get_ibs_caps(void) |
| { |
| return ibs_caps; |
| } |
| |
| EXPORT_SYMBOL(get_ibs_caps); |
| |
| static inline int get_eilvt(int offset) |
| { |
| return !setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 1); |
| } |
| |
| static inline int put_eilvt(int offset) |
| { |
| return !setup_APIC_eilvt(offset, 0, 0, 1); |
| } |
| |
| /* |
| * Check and reserve APIC extended interrupt LVT offset for IBS if available. |
| */ |
| static inline int ibs_eilvt_valid(void) |
| { |
| int offset; |
| u64 val; |
| int valid = 0; |
| |
| preempt_disable(); |
| |
| rdmsrl(MSR_AMD64_IBSCTL, val); |
| offset = val & IBSCTL_LVT_OFFSET_MASK; |
| |
| if (!(val & IBSCTL_LVT_OFFSET_VALID)) { |
| pr_err(FW_BUG "cpu %d, invalid IBS interrupt offset %d (MSR%08X=0x%016llx)\n", |
| smp_processor_id(), offset, MSR_AMD64_IBSCTL, val); |
| goto out; |
| } |
| |
| if (!get_eilvt(offset)) { |
| pr_err(FW_BUG "cpu %d, IBS interrupt offset %d not available (MSR%08X=0x%016llx)\n", |
| smp_processor_id(), offset, MSR_AMD64_IBSCTL, val); |
| goto out; |
| } |
| |
| valid = 1; |
| out: |
| preempt_enable(); |
| |
| return valid; |
| } |
| |
| static int setup_ibs_ctl(int ibs_eilvt_off) |
| { |
| struct pci_dev *cpu_cfg; |
| int nodes; |
| u32 value = 0; |
| |
| nodes = 0; |
| cpu_cfg = NULL; |
| do { |
| cpu_cfg = pci_get_device(PCI_VENDOR_ID_AMD, |
| PCI_DEVICE_ID_AMD_10H_NB_MISC, |
| cpu_cfg); |
| if (!cpu_cfg) |
| break; |
| ++nodes; |
| pci_write_config_dword(cpu_cfg, IBSCTL, ibs_eilvt_off |
| | IBSCTL_LVT_OFFSET_VALID); |
| pci_read_config_dword(cpu_cfg, IBSCTL, &value); |
| if (value != (ibs_eilvt_off | IBSCTL_LVT_OFFSET_VALID)) { |
| pci_dev_put(cpu_cfg); |
| pr_debug("Failed to setup IBS LVT offset, IBSCTL = 0x%08x\n", |
| value); |
| return -EINVAL; |
| } |
| } while (1); |
| |
| if (!nodes) { |
| pr_debug("No CPU node configured for IBS\n"); |
| return -ENODEV; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * This runs only on the current cpu. We try to find an LVT offset and |
| * setup the local APIC. For this we must disable preemption. On |
| * success we initialize all nodes with this offset. This updates then |
| * the offset in the IBS_CTL per-node msr. The per-core APIC setup of |
| * the IBS interrupt vector is handled by perf_ibs_cpu_notifier that |
| * is using the new offset. |
| */ |
| static void force_ibs_eilvt_setup(void) |
| { |
| int offset; |
| int ret; |
| |
| preempt_disable(); |
| /* find the next free available EILVT entry, skip offset 0 */ |
| for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) { |
| if (get_eilvt(offset)) |
| break; |
| } |
| preempt_enable(); |
| |
| if (offset == APIC_EILVT_NR_MAX) { |
| pr_debug("No EILVT entry available\n"); |
| return; |
| } |
| |
| ret = setup_ibs_ctl(offset); |
| if (ret) |
| goto out; |
| |
| if (!ibs_eilvt_valid()) |
| goto out; |
| |
| pr_info("IBS: LVT offset %d assigned\n", offset); |
| |
| return; |
| out: |
| preempt_disable(); |
| put_eilvt(offset); |
| preempt_enable(); |
| return; |
| } |
| |
| static void ibs_eilvt_setup(void) |
| { |
| /* |
| * Force LVT offset assignment for family 10h: The offsets are |
| * not assigned by the BIOS for this family, so the OS is |
| * responsible for doing it. If the OS assignment fails, fall |
| * back to BIOS settings and try to setup this. |
| */ |
| if (boot_cpu_data.x86 == 0x10) |
| force_ibs_eilvt_setup(); |
| } |
| |
| static inline int get_ibs_lvt_offset(void) |
| { |
| u64 val; |
| |
| rdmsrl(MSR_AMD64_IBSCTL, val); |
| if (!(val & IBSCTL_LVT_OFFSET_VALID)) |
| return -EINVAL; |
| |
| return val & IBSCTL_LVT_OFFSET_MASK; |
| } |
| |
| static void setup_APIC_ibs(void *dummy) |
| { |
| int offset; |
| |
| offset = get_ibs_lvt_offset(); |
| if (offset < 0) |
| goto failed; |
| |
| if (!setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_NMI, 0)) |
| return; |
| failed: |
| pr_warn("perf: IBS APIC setup failed on cpu #%d\n", |
| smp_processor_id()); |
| } |
| |
| static void clear_APIC_ibs(void *dummy) |
| { |
| int offset; |
| |
| offset = get_ibs_lvt_offset(); |
| if (offset >= 0) |
| setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1); |
| } |
| |
| #ifdef CONFIG_PM |
| |
| static int perf_ibs_suspend(void) |
| { |
| clear_APIC_ibs(NULL); |
| return 0; |
| } |
| |
| static void perf_ibs_resume(void) |
| { |
| ibs_eilvt_setup(); |
| setup_APIC_ibs(NULL); |
| } |
| |
| static struct syscore_ops perf_ibs_syscore_ops = { |
| .resume = perf_ibs_resume, |
| .suspend = perf_ibs_suspend, |
| }; |
| |
| static void perf_ibs_pm_init(void) |
| { |
| register_syscore_ops(&perf_ibs_syscore_ops); |
| } |
| |
| #else |
| |
| static inline void perf_ibs_pm_init(void) { } |
| |
| #endif |
| |
| static int |
| perf_ibs_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu) |
| { |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_STARTING: |
| setup_APIC_ibs(NULL); |
| break; |
| case CPU_DYING: |
| clear_APIC_ibs(NULL); |
| break; |
| default: |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static __init int amd_ibs_init(void) |
| { |
| u32 caps; |
| int ret = -EINVAL; |
| |
| caps = __get_ibs_caps(); |
| if (!caps) |
| return -ENODEV; /* ibs not supported by the cpu */ |
| |
| ibs_eilvt_setup(); |
| |
| if (!ibs_eilvt_valid()) |
| goto out; |
| |
| perf_ibs_pm_init(); |
| cpu_notifier_register_begin(); |
| ibs_caps = caps; |
| /* make ibs_caps visible to other cpus: */ |
| smp_mb(); |
| smp_call_function(setup_APIC_ibs, NULL, 1); |
| __perf_cpu_notifier(perf_ibs_cpu_notifier); |
| cpu_notifier_register_done(); |
| |
| ret = perf_event_ibs_init(); |
| out: |
| if (ret) |
| pr_err("Failed to setup IBS, %d\n", ret); |
| return ret; |
| } |
| |
| /* Since we need the pci subsystem to init ibs we can't do this earlier: */ |
| device_initcall(amd_ibs_init); |