1 files changed, 48 insertions, 3 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index b9698d40ac4b..8944062f46e2 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -45,6 +45,7 @@ struct event_constraint {
         u64     code;
         u64     cmask;
         int     weight;
+        int     overlap;
 };
 
 struct amd_nb {
@@ -151,15 +152,40 @@ struct cpu_hw_events {
         void                            *kfree_on_online;
 };
 
-#define __EVENT_CONSTRAINT(c, n, m, w) {\
+#define __EVENT_CONSTRAINT(c, n, m, w, o) {\
         { .idxmsk64 = (n) },            \
         .code = (c),                    \
         .cmask = (m),                   \
         .weight = (w),                  \
+        .overlap = (o),                 \
 }
 
 #define EVENT_CONSTRAINT(c, n, m)       \
-        __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n))
+        __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 0)
+
+/*
+ * The overlap flag marks event constraints with overlapping counter
+ * masks. This is the case if the counter mask of such an event is not
+ * a subset of any other counter mask of a constraint with an equal or
+ * higher weight, e.g.:
+ *
+ *  c_overlaps = EVENT_CONSTRAINT_OVERLAP(0, 0x09, 0);
+ *  c_another1 = EVENT_CONSTRAINT(0, 0x07, 0);
+ *  c_another2 = EVENT_CONSTRAINT(0, 0x38, 0);
+ *
+ * The event scheduler may not select the correct counter in the first
+ * cycle because it needs to know which subsequent events will be
+ * scheduled. It may fail to schedule the events then. So we set the
+ * overlap flag for such constraints to give the scheduler a hint which
+ * events to select for counter rescheduling.
+ *
+ * Care must be taken as the rescheduling algorithm is O(n!) which
+ * will increase scheduling cycles for an over-commited system
+ * dramatically.  The number of such EVENT_CONSTRAINT_OVERLAP() macros
+ * and its counter masks must be kept at a minimum.
+ */
+#define EVENT_CONSTRAINT_OVERLAP(c, n, m)       \
+        __EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 1)
 
 /*
  * Constraint on the Event code.
@@ -235,6 +261,11 @@ union perf_capabilities {
         u64     capabilities;
 };
 
+struct x86_pmu_quirk {
+        struct x86_pmu_quirk *next;
+        void (*func)(void);
+};
+
 /*
  * struct x86_pmu - generic x86 pmu
  */
@@ -259,6 +290,11 @@ struct x86_pmu {
         int             num_counters_fixed;
         int             cntval_bits;
         u64             cntval_mask;
+        union {
+                        unsigned long events_maskl;
+                        unsigned long events_mask[BITS_TO_LONGS(ARCH_PERFMON_EVENTS_COUNT)];
+        };
+        int             events_mask_len;
         int             apic;
         u64             max_period;
         struct event_constraint *
@@ -268,7 +304,7 @@ struct x86_pmu {
         void            (*put_event_constraints)(struct cpu_hw_events *cpuc,
                                                  struct perf_event *event);
         struct event_constraint *event_constraints;
-        void            (*quirks)(void);
+        struct x86_pmu_quirk *quirks;
         int             perfctr_second_write;
 
         int             (*cpu_prepare)(int cpu);
@@ -309,6 +345,15 @@ struct x86_pmu {
         struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr);
 };
 
+#define x86_add_quirk(func_)                                            \
+do {                                                                    \
+        static struct x86_pmu_quirk __quirk __initdata = {              \
+                .func = func_,                                          \
+        };                                                              \
+        __quirk.next = x86_pmu.quirks;                                  \
+        x86_pmu.quirks = &__quirk;                                      \
+} while (0)
+
 #define ERF_NO_HT_SHARING       1
 #define ERF_HAS_RSP_1           2