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-rw-r--r--arch/x86/events/amd/ibs.c988
1 files changed, 988 insertions, 0 deletions
diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
new file mode 100644
index 000000000000..3ea25c3917c0
--- /dev/null
+++ b/arch/x86/events/amd/ibs.c
@@ -0,0 +1,988 @@
+/*
+ * 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(&regs, 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, &regs);
+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);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-25 22:25:15 +0000