perf, x86: Implement simple LBR support

Implement simple suport Intel Last-Branch-Record, it supports all
hardware that implements FREEZE_LBRS_ON_PMI, but does not (yet) implement
the LBR config register.

The Intel LBR is a FIFO of From,To addresses describing the last few
branches the hardware took.

This patch does not add perf interface to the LBR, but merely provides an
interface for internal use.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <20100304140100.544191154@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 13 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 11446412e4c..44f6ed42a93 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -480,6 +480,7 @@ static void intel_pmu_disable_all(void)
                 intel_pmu_disable_bts();
 
         intel_pmu_pebs_disable_all();
+        intel_pmu_lbr_disable_all();
 }
 
 static void intel_pmu_enable_all(void)
@@ -499,6 +500,7 @@ static void intel_pmu_enable_all(void)
         }
 
         intel_pmu_pebs_enable_all();
+        intel_pmu_lbr_enable_all();
 }
 
 static inline u64 intel_pmu_get_status(void)
@@ -674,6 +676,8 @@ again:
         inc_irq_stat(apic_perf_irqs);
         ack = status;
 
+        intel_pmu_lbr_read();
+
         /*
          * PEBS overflow sets bit 62 in the global status register
          */
@@ -848,6 +852,8 @@ static __init int intel_pmu_init(void)
                 memcpy(hw_cache_event_ids, core2_hw_cache_event_ids,
                        sizeof(hw_cache_event_ids));
 
+                intel_pmu_lbr_init_core();
+
                 x86_pmu.event_constraints = intel_core2_event_constraints;
                 pr_cont("Core2 events, ");
                 break;
@@ -857,13 +863,18 @@ static __init int intel_pmu_init(void)
                 memcpy(hw_cache_event_ids, nehalem_hw_cache_event_ids,
                        sizeof(hw_cache_event_ids));
 
+                intel_pmu_lbr_init_nhm();
+
                 x86_pmu.event_constraints = intel_nehalem_event_constraints;
                 pr_cont("Nehalem/Corei7 events, ");
                 break;
+
         case 28: /* Atom */
                 memcpy(hw_cache_event_ids, atom_hw_cache_event_ids,
                        sizeof(hw_cache_event_ids));
 
+                intel_pmu_lbr_init_atom();
+
                 x86_pmu.event_constraints = intel_gen_event_constraints;
                 pr_cont("Atom events, ");
                 break;
@@ -873,6 +884,8 @@ static __init int intel_pmu_init(void)
                 memcpy(hw_cache_event_ids, westmere_hw_cache_event_ids,
                        sizeof(hw_cache_event_ids));
 
+                intel_pmu_lbr_init_nhm();
+
                 x86_pmu.event_constraints = intel_westmere_event_constraints;
                 pr_cont("Westmere events, ");
                 break;