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Diffstat (limited to 'arch/x86/kernel/cpu/perf_event_intel_ds.c')
-rw-r--r--arch/x86/kernel/cpu/perf_event_intel_ds.c641
1 files changed, 641 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
new file mode 100644
index 000000000000..18018d1311cd
--- /dev/null
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -0,0 +1,641 @@
+#ifdef CONFIG_CPU_SUP_INTEL
+
+/* The maximal number of PEBS events: */
+#define MAX_PEBS_EVENTS 4
+
+/* The size of a BTS record in bytes: */
+#define BTS_RECORD_SIZE 24
+
+#define BTS_BUFFER_SIZE (PAGE_SIZE << 4)
+#define PEBS_BUFFER_SIZE PAGE_SIZE
+
+/*
+ * pebs_record_32 for p4 and core not supported
+
+struct pebs_record_32 {
+ u32 flags, ip;
+ u32 ax, bc, cx, dx;
+ u32 si, di, bp, sp;
+};
+
+ */
+
+struct pebs_record_core {
+ u64 flags, ip;
+ u64 ax, bx, cx, dx;
+ u64 si, di, bp, sp;
+ u64 r8, r9, r10, r11;
+ u64 r12, r13, r14, r15;
+};
+
+struct pebs_record_nhm {
+ u64 flags, ip;
+ u64 ax, bx, cx, dx;
+ u64 si, di, bp, sp;
+ u64 r8, r9, r10, r11;
+ u64 r12, r13, r14, r15;
+ u64 status, dla, dse, lat;
+};
+
+/*
+ * A debug store configuration.
+ *
+ * We only support architectures that use 64bit fields.
+ */
+struct debug_store {
+ u64 bts_buffer_base;
+ u64 bts_index;
+ u64 bts_absolute_maximum;
+ u64 bts_interrupt_threshold;
+ u64 pebs_buffer_base;
+ u64 pebs_index;
+ u64 pebs_absolute_maximum;
+ u64 pebs_interrupt_threshold;
+ u64 pebs_event_reset[MAX_PEBS_EVENTS];
+};
+
+static void init_debug_store_on_cpu(int cpu)
+{
+ struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+ if (!ds)
+ return;
+
+ wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA,
+ (u32)((u64)(unsigned long)ds),
+ (u32)((u64)(unsigned long)ds >> 32));
+}
+
+static void fini_debug_store_on_cpu(int cpu)
+{
+ if (!per_cpu(cpu_hw_events, cpu).ds)
+ return;
+
+ wrmsr_on_cpu(cpu, MSR_IA32_DS_AREA, 0, 0);
+}
+
+static void release_ds_buffers(void)
+{
+ int cpu;
+
+ if (!x86_pmu.bts && !x86_pmu.pebs)
+ return;
+
+ get_online_cpus();
+
+ for_each_online_cpu(cpu)
+ fini_debug_store_on_cpu(cpu);
+
+ for_each_possible_cpu(cpu) {
+ struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
+
+ if (!ds)
+ continue;
+
+ per_cpu(cpu_hw_events, cpu).ds = NULL;
+
+ kfree((void *)(unsigned long)ds->pebs_buffer_base);
+ kfree((void *)(unsigned long)ds->bts_buffer_base);
+ kfree(ds);
+ }
+
+ put_online_cpus();
+}
+
+static int reserve_ds_buffers(void)
+{
+ int cpu, err = 0;
+
+ if (!x86_pmu.bts && !x86_pmu.pebs)
+ return 0;
+
+ get_online_cpus();
+
+ for_each_possible_cpu(cpu) {
+ struct debug_store *ds;
+ void *buffer;
+ int max, thresh;
+
+ err = -ENOMEM;
+ ds = kzalloc(sizeof(*ds), GFP_KERNEL);
+ if (unlikely(!ds))
+ break;
+ per_cpu(cpu_hw_events, cpu).ds = ds;
+
+ if (x86_pmu.bts) {
+ buffer = kzalloc(BTS_BUFFER_SIZE, GFP_KERNEL);
+ if (unlikely(!buffer))
+ break;
+
+ max = BTS_BUFFER_SIZE / BTS_RECORD_SIZE;
+ thresh = max / 16;
+
+ ds->bts_buffer_base = (u64)(unsigned long)buffer;
+ ds->bts_index = ds->bts_buffer_base;
+ ds->bts_absolute_maximum = ds->bts_buffer_base +
+ max * BTS_RECORD_SIZE;
+ ds->bts_interrupt_threshold = ds->bts_absolute_maximum -
+ thresh * BTS_RECORD_SIZE;
+ }
+
+ if (x86_pmu.pebs) {
+ buffer = kzalloc(PEBS_BUFFER_SIZE, GFP_KERNEL);
+ if (unlikely(!buffer))
+ break;
+
+ max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
+
+ ds->pebs_buffer_base = (u64)(unsigned long)buffer;
+ ds->pebs_index = ds->pebs_buffer_base;
+ ds->pebs_absolute_maximum = ds->pebs_buffer_base +
+ max * x86_pmu.pebs_record_size;
+ /*
+ * Always use single record PEBS
+ */
+ ds->pebs_interrupt_threshold = ds->pebs_buffer_base +
+ x86_pmu.pebs_record_size;
+ }
+
+ err = 0;
+ }
+
+ if (err)
+ release_ds_buffers();
+ else {
+ for_each_online_cpu(cpu)
+ init_debug_store_on_cpu(cpu);
+ }
+
+ put_online_cpus();
+
+ return err;
+}
+
+/*
+ * BTS
+ */
+
+static struct event_constraint bts_constraint =
+ EVENT_CONSTRAINT(0, 1ULL << X86_PMC_IDX_FIXED_BTS, 0);
+
+static void intel_pmu_enable_bts(u64 config)
+{
+ unsigned long debugctlmsr;
+
+ debugctlmsr = get_debugctlmsr();
+
+ debugctlmsr |= DEBUGCTLMSR_TR;
+ debugctlmsr |= DEBUGCTLMSR_BTS;
+ debugctlmsr |= DEBUGCTLMSR_BTINT;
+
+ if (!(config & ARCH_PERFMON_EVENTSEL_OS))
+ debugctlmsr |= DEBUGCTLMSR_BTS_OFF_OS;
+
+ if (!(config & ARCH_PERFMON_EVENTSEL_USR))
+ debugctlmsr |= DEBUGCTLMSR_BTS_OFF_USR;
+
+ update_debugctlmsr(debugctlmsr);
+}
+
+static void intel_pmu_disable_bts(void)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ unsigned long debugctlmsr;
+
+ if (!cpuc->ds)
+ return;
+
+ debugctlmsr = get_debugctlmsr();
+
+ debugctlmsr &=
+ ~(DEBUGCTLMSR_TR | DEBUGCTLMSR_BTS | DEBUGCTLMSR_BTINT |
+ DEBUGCTLMSR_BTS_OFF_OS | DEBUGCTLMSR_BTS_OFF_USR);
+
+ update_debugctlmsr(debugctlmsr);
+}
+
+static void intel_pmu_drain_bts_buffer(void)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct debug_store *ds = cpuc->ds;
+ struct bts_record {
+ u64 from;
+ u64 to;
+ u64 flags;
+ };
+ struct perf_event *event = cpuc->events[X86_PMC_IDX_FIXED_BTS];
+ struct bts_record *at, *top;
+ struct perf_output_handle handle;
+ struct perf_event_header header;
+ struct perf_sample_data data;
+ struct pt_regs regs;
+
+ if (!event)
+ return;
+
+ if (!ds)
+ return;
+
+ at = (struct bts_record *)(unsigned long)ds->bts_buffer_base;
+ top = (struct bts_record *)(unsigned long)ds->bts_index;
+
+ if (top <= at)
+ return;
+
+ ds->bts_index = ds->bts_buffer_base;
+
+ perf_sample_data_init(&data, 0);
+ data.period = event->hw.last_period;
+ regs.ip = 0;
+
+ /*
+ * Prepare a generic sample, i.e. fill in the invariant fields.
+ * We will overwrite the from and to address before we output
+ * the sample.
+ */
+ perf_prepare_sample(&header, &data, event, &regs);
+
+ if (perf_output_begin(&handle, event, header.size * (top - at), 1, 1))
+ return;
+
+ for (; at < top; at++) {
+ data.ip = at->from;
+ data.addr = at->to;
+
+ perf_output_sample(&handle, &header, &data, event);
+ }
+
+ perf_output_end(&handle);
+
+ /* There's new data available. */
+ event->hw.interrupts++;
+ event->pending_kill = POLL_IN;
+}
+
+/*
+ * PEBS
+ */
+
+static struct event_constraint intel_core_pebs_events[] = {
+ PEBS_EVENT_CONSTRAINT(0x00c0, 0x1), /* INSTR_RETIRED.ANY */
+ PEBS_EVENT_CONSTRAINT(0xfec1, 0x1), /* X87_OPS_RETIRED.ANY */
+ PEBS_EVENT_CONSTRAINT(0x00c5, 0x1), /* BR_INST_RETIRED.MISPRED */
+ PEBS_EVENT_CONSTRAINT(0x1fc7, 0x1), /* SIMD_INST_RETURED.ANY */
+ PEBS_EVENT_CONSTRAINT(0x01cb, 0x1), /* MEM_LOAD_RETIRED.L1D_MISS */
+ PEBS_EVENT_CONSTRAINT(0x02cb, 0x1), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */
+ PEBS_EVENT_CONSTRAINT(0x04cb, 0x1), /* MEM_LOAD_RETIRED.L2_MISS */
+ PEBS_EVENT_CONSTRAINT(0x08cb, 0x1), /* MEM_LOAD_RETIRED.L2_LINE_MISS */
+ PEBS_EVENT_CONSTRAINT(0x10cb, 0x1), /* MEM_LOAD_RETIRED.DTLB_MISS */
+ EVENT_CONSTRAINT_END
+};
+
+static struct event_constraint intel_nehalem_pebs_events[] = {
+ PEBS_EVENT_CONSTRAINT(0x00c0, 0xf), /* INSTR_RETIRED.ANY */
+ PEBS_EVENT_CONSTRAINT(0xfec1, 0xf), /* X87_OPS_RETIRED.ANY */
+ PEBS_EVENT_CONSTRAINT(0x00c5, 0xf), /* BR_INST_RETIRED.MISPRED */
+ PEBS_EVENT_CONSTRAINT(0x1fc7, 0xf), /* SIMD_INST_RETURED.ANY */
+ PEBS_EVENT_CONSTRAINT(0x01cb, 0xf), /* MEM_LOAD_RETIRED.L1D_MISS */
+ PEBS_EVENT_CONSTRAINT(0x02cb, 0xf), /* MEM_LOAD_RETIRED.L1D_LINE_MISS */
+ PEBS_EVENT_CONSTRAINT(0x04cb, 0xf), /* MEM_LOAD_RETIRED.L2_MISS */
+ PEBS_EVENT_CONSTRAINT(0x08cb, 0xf), /* MEM_LOAD_RETIRED.L2_LINE_MISS */
+ PEBS_EVENT_CONSTRAINT(0x10cb, 0xf), /* MEM_LOAD_RETIRED.DTLB_MISS */
+ EVENT_CONSTRAINT_END
+};
+
+static struct event_constraint *
+intel_pebs_constraints(struct perf_event *event)
+{
+ struct event_constraint *c;
+
+ if (!event->attr.precise_ip)
+ return NULL;
+
+ if (x86_pmu.pebs_constraints) {
+ for_each_event_constraint(c, x86_pmu.pebs_constraints) {
+ if ((event->hw.config & c->cmask) == c->code)
+ return c;
+ }
+ }
+
+ return &emptyconstraint;
+}
+
+static void intel_pmu_pebs_enable(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+
+ hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
+
+ cpuc->pebs_enabled |= 1ULL << hwc->idx;
+ WARN_ON_ONCE(cpuc->enabled);
+
+ if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1)
+ intel_pmu_lbr_enable(event);
+}
+
+static void intel_pmu_pebs_disable(struct perf_event *event)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct hw_perf_event *hwc = &event->hw;
+
+ cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
+ if (cpuc->enabled)
+ wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
+
+ hwc->config |= ARCH_PERFMON_EVENTSEL_INT;
+
+ if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1)
+ intel_pmu_lbr_disable(event);
+}
+
+static void intel_pmu_pebs_enable_all(void)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+ if (cpuc->pebs_enabled)
+ wrmsrl(MSR_IA32_PEBS_ENABLE, cpuc->pebs_enabled);
+}
+
+static void intel_pmu_pebs_disable_all(void)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+
+ if (cpuc->pebs_enabled)
+ wrmsrl(MSR_IA32_PEBS_ENABLE, 0);
+}
+
+#include <asm/insn.h>
+
+static inline bool kernel_ip(unsigned long ip)
+{
+#ifdef CONFIG_X86_32
+ return ip > PAGE_OFFSET;
+#else
+ return (long)ip < 0;
+#endif
+}
+
+static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ unsigned long from = cpuc->lbr_entries[0].from;
+ unsigned long old_to, to = cpuc->lbr_entries[0].to;
+ unsigned long ip = regs->ip;
+
+ /*
+ * We don't need to fixup if the PEBS assist is fault like
+ */
+ if (!x86_pmu.intel_cap.pebs_trap)
+ return 1;
+
+ /*
+ * No LBR entry, no basic block, no rewinding
+ */
+ if (!cpuc->lbr_stack.nr || !from || !to)
+ return 0;
+
+ /*
+ * Basic blocks should never cross user/kernel boundaries
+ */
+ if (kernel_ip(ip) != kernel_ip(to))
+ return 0;
+
+ /*
+ * unsigned math, either ip is before the start (impossible) or
+ * the basic block is larger than 1 page (sanity)
+ */
+ if ((ip - to) > PAGE_SIZE)
+ return 0;
+
+ /*
+ * We sampled a branch insn, rewind using the LBR stack
+ */
+ if (ip == to) {
+ regs->ip = from;
+ return 1;
+ }
+
+ do {
+ struct insn insn;
+ u8 buf[MAX_INSN_SIZE];
+ void *kaddr;
+
+ old_to = to;
+ if (!kernel_ip(ip)) {
+ int bytes, size = MAX_INSN_SIZE;
+
+ bytes = copy_from_user_nmi(buf, (void __user *)to, size);
+ if (bytes != size)
+ return 0;
+
+ kaddr = buf;
+ } else
+ kaddr = (void *)to;
+
+ kernel_insn_init(&insn, kaddr);
+ insn_get_length(&insn);
+ to += insn.length;
+ } while (to < ip);
+
+ if (to == ip) {
+ regs->ip = old_to;
+ return 1;
+ }
+
+ /*
+ * Even though we decoded the basic block, the instruction stream
+ * never matched the given IP, either the TO or the IP got corrupted.
+ */
+ return 0;
+}
+
+static int intel_pmu_save_and_restart(struct perf_event *event);
+
+static void __intel_pmu_pebs_event(struct perf_event *event,
+ struct pt_regs *iregs, void *__pebs)
+{
+ /*
+ * We cast to pebs_record_core since that is a subset of
+ * both formats and we don't use the other fields in this
+ * routine.
+ */
+ struct pebs_record_core *pebs = __pebs;
+ struct perf_sample_data data;
+ struct pt_regs regs;
+
+ if (!intel_pmu_save_and_restart(event))
+ return;
+
+ perf_sample_data_init(&data, 0);
+ data.period = event->hw.last_period;
+
+ /*
+ * We use the interrupt regs as a base because the PEBS record
+ * does not contain a full regs set, specifically it seems to
+ * lack segment descriptors, which get used by things like
+ * user_mode().
+ *
+ * In the simple case fix up only the IP and BP,SP regs, for
+ * PERF_SAMPLE_IP and PERF_SAMPLE_CALLCHAIN to function properly.
+ * A possible PERF_SAMPLE_REGS will have to transfer all regs.
+ */
+ regs = *iregs;
+ regs.ip = pebs->ip;
+ regs.bp = pebs->bp;
+ regs.sp = pebs->sp;
+
+ if (event->attr.precise_ip > 1 && intel_pmu_pebs_fixup_ip(&regs))
+ regs.flags |= PERF_EFLAGS_EXACT;
+ else
+ regs.flags &= ~PERF_EFLAGS_EXACT;
+
+ if (perf_event_overflow(event, 1, &data, &regs))
+ x86_pmu_stop(event);
+}
+
+static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct debug_store *ds = cpuc->ds;
+ struct perf_event *event = cpuc->events[0]; /* PMC0 only */
+ struct pebs_record_core *at, *top;
+ int n;
+
+ if (!ds || !x86_pmu.pebs)
+ return;
+
+ at = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
+ top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
+
+ /*
+ * Whatever else happens, drain the thing
+ */
+ ds->pebs_index = ds->pebs_buffer_base;
+
+ if (!test_bit(0, cpuc->active_mask))
+ return;
+
+ WARN_ON_ONCE(!event);
+
+ if (!event->attr.precise_ip)
+ return;
+
+ n = top - at;
+ if (n <= 0)
+ return;
+
+ /*
+ * Should not happen, we program the threshold at 1 and do not
+ * set a reset value.
+ */
+ WARN_ON_ONCE(n > 1);
+ at += n - 1;
+
+ __intel_pmu_pebs_event(event, iregs, at);
+}
+
+static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
+{
+ struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
+ struct debug_store *ds = cpuc->ds;
+ struct pebs_record_nhm *at, *top;
+ struct perf_event *event = NULL;
+ u64 status = 0;
+ int bit, n;
+
+ if (!ds || !x86_pmu.pebs)
+ return;
+
+ at = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
+ top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
+
+ ds->pebs_index = ds->pebs_buffer_base;
+
+ n = top - at;
+ if (n <= 0)
+ return;
+
+ /*
+ * Should not happen, we program the threshold at 1 and do not
+ * set a reset value.
+ */
+ WARN_ON_ONCE(n > MAX_PEBS_EVENTS);
+
+ for ( ; at < top; at++) {
+ for_each_set_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) {
+ event = cpuc->events[bit];
+ if (!test_bit(bit, cpuc->active_mask))
+ continue;
+
+ WARN_ON_ONCE(!event);
+
+ if (!event->attr.precise_ip)
+ continue;
+
+ if (__test_and_set_bit(bit, (unsigned long *)&status))
+ continue;
+
+ break;
+ }
+
+ if (!event || bit >= MAX_PEBS_EVENTS)
+ continue;
+
+ __intel_pmu_pebs_event(event, iregs, at);
+ }
+}
+
+/*
+ * BTS, PEBS probe and setup
+ */
+
+static void intel_ds_init(void)
+{
+ /*
+ * No support for 32bit formats
+ */
+ if (!boot_cpu_has(X86_FEATURE_DTES64))
+ return;
+
+ x86_pmu.bts = boot_cpu_has(X86_FEATURE_BTS);
+ x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
+ if (x86_pmu.pebs) {
+ char pebs_type = x86_pmu.intel_cap.pebs_trap ? '+' : '-';
+ int format = x86_pmu.intel_cap.pebs_format;
+
+ switch (format) {
+ case 0:
+ printk(KERN_CONT "PEBS fmt0%c, ", pebs_type);
+ x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
+ x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
+ x86_pmu.pebs_constraints = intel_core_pebs_events;
+ break;
+
+ case 1:
+ printk(KERN_CONT "PEBS fmt1%c, ", pebs_type);
+ x86_pmu.pebs_record_size = sizeof(struct pebs_record_nhm);
+ x86_pmu.drain_pebs = intel_pmu_drain_pebs_nhm;
+ x86_pmu.pebs_constraints = intel_nehalem_pebs_events;
+ break;
+
+ default:
+ printk(KERN_CONT "no PEBS fmt%d%c, ", format, pebs_type);
+ x86_pmu.pebs = 0;
+ break;
+ }
+ }
+}
+
+#else /* CONFIG_CPU_SUP_INTEL */
+
+static int reserve_ds_buffers(void)
+{
+ return 0;
+}
+
+static void release_ds_buffers(void)
+{
+}
+
+#endif /* CONFIG_CPU_SUP_INTEL */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.