Merge remote-tracking branches 'asoc/topic/rl6231', 'asoc/topic/rt5514', 'asoc/topic...

[sfrench/cifs-2.6.git] / arch / x86 / events / intel / bts.c

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 141e07b0621689e745582599c009f4af1d053c6c..24ffa1e88cf948ecbe9839f6d956c69a12ecd4f0 100644 (file)
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -582,6 +582,24 @@ static __init int bts_init(void)
        if (!boot_cpu_has(X86_FEATURE_DTES64) || !x86_pmu.bts)
                return -ENODEV;
 
+       if (boot_cpu_has(X86_FEATURE_PTI)) {
+               /*
+                * BTS hardware writes through a virtual memory map we must
+                * either use the kernel physical map, or the user mapping of
+                * the AUX buffer.
+                *
+                * However, since this driver supports per-CPU and per-task inherit
+                * we cannot use the user mapping since it will not be availble
+                * if we're not running the owning process.
+                *
+                * With PTI we can't use the kernal map either, because its not
+                * there when we run userspace.
+                *
+                * For now, disable this driver when using PTI.
+                */
+               return -ENODEV;
+       }
+
        bts_pmu.capabilities    = PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_ITRACE |
                                  PERF_PMU_CAP_EXCLUSIVE;
        bts_pmu.task_ctx_nr     = perf_sw_context;