+/*
+ * 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;
+}
+