1 files changed, 108 insertions, 37 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 166546ec6aef..187c294bc658 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1119,27 +1119,33 @@ intel_bts_constraints(struct perf_event *event)
         return NULL;
 }
 
-static bool intel_try_alt_er(struct perf_event *event, int orig_idx)
+static int intel_alt_er(int idx)
 {
         if (!(x86_pmu.er_flags & ERF_HAS_RSP_1))
-                return false;
+                return idx;
 
-        if (event->hw.extra_reg.idx == EXTRA_REG_RSP_0) {
-                event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
-                event->hw.config |= 0x01bb;
-                event->hw.extra_reg.idx = EXTRA_REG_RSP_1;
-                event->hw.extra_reg.reg = MSR_OFFCORE_RSP_1;
-        } else if (event->hw.extra_reg.idx == EXTRA_REG_RSP_1) {
+        if (idx == EXTRA_REG_RSP_0)
+                return EXTRA_REG_RSP_1;
+
+        if (idx == EXTRA_REG_RSP_1)
+                return EXTRA_REG_RSP_0;
+
+        return idx;
+}
+
+static void intel_fixup_er(struct perf_event *event, int idx)
+{
+        event->hw.extra_reg.idx = idx;
+
+        if (idx == EXTRA_REG_RSP_0) {
                 event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
                 event->hw.config |= 0x01b7;
-                event->hw.extra_reg.idx = EXTRA_REG_RSP_0;
                 event->hw.extra_reg.reg = MSR_OFFCORE_RSP_0;
+        } else if (idx == EXTRA_REG_RSP_1) {
+                event->hw.config &= ~INTEL_ARCH_EVENT_MASK;
+                event->hw.config |= 0x01bb;
+                event->hw.extra_reg.reg = MSR_OFFCORE_RSP_1;
         }
-
-        if (event->hw.extra_reg.idx == orig_idx)
-                return false;
-
-        return true;
 }
 
 /*
@@ -1157,14 +1163,18 @@ __intel_shared_reg_get_constraints(struct cpu_hw_events *cpuc,
         struct event_constraint *c = &emptyconstraint;
         struct er_account *era;
         unsigned long flags;
-        int orig_idx = reg->idx;
+        int idx = reg->idx;
 
-        /* already allocated shared msr */
-        if (reg->alloc)
+        /*
+         * reg->alloc can be set due to existing state, so for fake cpuc we
+         * need to ignore this, otherwise we might fail to allocate proper fake
+         * state for this extra reg constraint. Also see the comment below.
+         */
+        if (reg->alloc && !cpuc->is_fake)
                 return NULL; /* call x86_get_event_constraint() */
 
 again:
-        era = &cpuc->shared_regs->regs[reg->idx];
+        era = &cpuc->shared_regs->regs[idx];
         /*
          * we use spin_lock_irqsave() to avoid lockdep issues when
          * passing a fake cpuc
@@ -1173,6 +1183,29 @@ again:
 
         if (!atomic_read(&era->ref) || era->config == reg->config) {
 
+                /*
+                 * If its a fake cpuc -- as per validate_{group,event}() we
+                 * shouldn't touch event state and we can avoid doing so
+                 * since both will only call get_event_constraints() once
+                 * on each event, this avoids the need for reg->alloc.
+                 *
+                 * Not doing the ER fixup will only result in era->reg being
+                 * wrong, but since we won't actually try and program hardware
+                 * this isn't a problem either.
+                 */
+                if (!cpuc->is_fake) {
+                        if (idx != reg->idx)
+                                intel_fixup_er(event, idx);
+
+                        /*
+                         * x86_schedule_events() can call get_event_constraints()
+                         * multiple times on events in the case of incremental
+                         * scheduling(). reg->alloc ensures we only do the ER
+                         * allocation once.
+                         */
+                        reg->alloc = 1;
+                }
+
                 /* lock in msr value */
                 era->config = reg->config;
                 era->reg = reg->reg;
@@ -1180,17 +1213,17 @@ again:
                 /* one more user */
                 atomic_inc(&era->ref);
 
-                /* no need to reallocate during incremental event scheduling */
-                reg->alloc = 1;
-
                 /*
                  * need to call x86_get_event_constraint()
                  * to check if associated event has constraints
                  */
                 c = NULL;
-        } else if (intel_try_alt_er(event, orig_idx)) {
-                raw_spin_unlock_irqrestore(&era->lock, flags);
-                goto again;
+        } else {
+                idx = intel_alt_er(idx);
+                if (idx != reg->idx) {
+                        raw_spin_unlock_irqrestore(&era->lock, flags);
+                        goto again;
+                }
         }
         raw_spin_unlock_irqrestore(&era->lock, flags);
 
@@ -1204,11 +1237,14 @@ __intel_shared_reg_put_constraints(struct cpu_hw_events *cpuc,
         struct er_account *era;
 
         /*
-         * only put constraint if extra reg was actually
-         * allocated. Also takes care of event which do
-         * not use an extra shared reg
+         * Only put constraint if extra reg was actually allocated. Also takes
+         * care of event which do not use an extra shared reg.
+         *
+         * Also, if this is a fake cpuc we shouldn't touch any event state
+         * (reg->alloc) and we don't care about leaving inconsistent cpuc state
+         * either since it'll be thrown out.
          */
-        if (!reg->alloc)
+        if (!reg->alloc || cpuc->is_fake)
                 return;
 
         era = &cpuc->shared_regs->regs[reg->idx];
@@ -1300,15 +1336,9 @@ static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
         intel_put_shared_regs_event_constraints(cpuc, event);
 }
 
-static int intel_pmu_hw_config(struct perf_event *event)
+static void intel_pebs_aliases_core2(struct perf_event *event)
 {
-        int ret = x86_pmu_hw_config(event);
-
-        if (ret)
-                return ret;
-
-        if (event->attr.precise_ip &&
-            (event->hw.config & X86_RAW_EVENT_MASK) == 0x003c) {
+        if ((event->hw.config & X86_RAW_EVENT_MASK) == 0x003c) {
                 /*
                  * Use an alternative encoding for CPU_CLK_UNHALTED.THREAD_P
                  * (0x003c) so that we can use it with PEBS.
@@ -1329,10 +1359,48 @@ static int intel_pmu_hw_config(struct perf_event *event)
                  */
                 u64 alt_config = X86_CONFIG(.event=0xc0, .inv=1, .cmask=16);
 
+                alt_config |= (event->hw.config & ~X86_RAW_EVENT_MASK);
+                event->hw.config = alt_config;
+        }
+}
+
+static void intel_pebs_aliases_snb(struct perf_event *event)
+{
+        if ((event->hw.config & X86_RAW_EVENT_MASK) == 0x003c) {
+                /*
+                 * Use an alternative encoding for CPU_CLK_UNHALTED.THREAD_P
+                 * (0x003c) so that we can use it with PEBS.
+                 *
+                 * The regular CPU_CLK_UNHALTED.THREAD_P event (0x003c) isn't
+                 * PEBS capable. However we can use UOPS_RETIRED.ALL
+                 * (0x01c2), which is a PEBS capable event, to get the same
+                 * count.
+                 *
+                 * UOPS_RETIRED.ALL counts the number of cycles that retires
+                 * CNTMASK micro-ops. By setting CNTMASK to a value (16)
+                 * larger than the maximum number of micro-ops that can be
+                 * retired per cycle (4) and then inverting the condition, we
+                 * count all cycles that retire 16 or less micro-ops, which
+                 * is every cycle.
+                 *
+                 * Thereby we gain a PEBS capable cycle counter.
+                 */
+                u64 alt_config = X86_CONFIG(.event=0xc2, .umask=0x01, .inv=1, .cmask=16);
 
                 alt_config |= (event->hw.config & ~X86_RAW_EVENT_MASK);
                 event->hw.config = alt_config;
         }
+}
+
+static int intel_pmu_hw_config(struct perf_event *event)
+{
+        int ret = x86_pmu_hw_config(event);
+
+        if (ret)
+                return ret;
+
+        if (event->attr.precise_ip && x86_pmu.pebs_aliases)
+                x86_pmu.pebs_aliases(event);
 
         if (intel_pmu_needs_lbr_smpl(event)) {
                 ret = intel_pmu_setup_lbr_filter(event);
@@ -1607,6 +1675,7 @@ static __initconst const struct x86_pmu intel_pmu = {
         .max_period             = (1ULL << 31) - 1,
         .get_event_constraints  = intel_get_event_constraints,
         .put_event_constraints  = intel_put_event_constraints,
+        .pebs_aliases           = intel_pebs_aliases_core2,
 
         .format_attrs           = intel_arch3_formats_attr,
 
@@ -1840,8 +1909,9 @@ __init int intel_pmu_init(void)
                 break;
 
         case 42: /* SandyBridge */
-                x86_add_quirk(intel_sandybridge_quirk);
         case 45: /* SandyBridge, "Romely-EP" */
+                x86_add_quirk(intel_sandybridge_quirk);
+        case 58: /* IvyBridge */
                 memcpy(hw_cache_event_ids, snb_hw_cache_event_ids,
                        sizeof(hw_cache_event_ids));
 
@@ -1849,6 +1919,7 @@ __init int intel_pmu_init(void)
 
                 x86_pmu.event_constraints = intel_snb_event_constraints;
                 x86_pmu.pebs_constraints = intel_snb_pebs_event_constraints;
+                x86_pmu.pebs_aliases = intel_pebs_aliases_snb;
                 x86_pmu.extra_regs = intel_snb_extra_regs;
                 /* all extra regs are per-cpu when HT is on */
                 x86_pmu.er_flags |= ERF_HAS_RSP_1;