x86/oprofile: add CONFIG_OPROFILE_IBS option

Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 37 insertions, 10 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index b0fabfa864ff..2651af48b2e5 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -13,6 +13,20 @@ config OPROFILE
 
           If unsure, say N.
 
+config OPROFILE_IBS
+        bool "OProfile AMD IBS support (EXPERIMENTAL)"
+        default n
+        depends on OPROFILE && SMP && X86
+        help
+          Instruction-Based Sampling (IBS) is a new profiling
+          technique that provides rich, precise program performance
+          information. IBS is introduced by AMD Family10h processors
+          (AMD Opteron Quad-Core processor “Barcelona”) to overcome
+          the limitations of conventional performance counter
+          sampling.
+
+          If unsure, say N.
+
 config HAVE_OPROFILE
         def_bool n
 
diff --git a/arch/x86/oprofile/op_model_athlon.c b/arch/x86/oprofile/op_model_athlon.c
index 9c8c8c583132..fb6015c1132b 100644
--- a/arch/x86/oprofile/op_model_athlon.c
+++ b/arch/x86/oprofile/op_model_athlon.c
@@ -47,6 +47,10 @@
 #define CTRL_SET_HOST_ONLY(val, h) (val |= ((h & 1) << 9))
 #define CTRL_SET_GUEST_ONLY(val, h) (val |= ((h & 1) << 8))
 
+static unsigned long reset_value[NUM_COUNTERS];
+
+#ifdef CONFIG_OPROFILE_IBS
+
 /* IbsFetchCtl bits/masks */
 #define IBS_FETCH_HIGH_VALID_BIT        (1UL << 17)     /* bit 49 */
 #define IBS_FETCH_HIGH_ENABLE           (1UL << 16)     /* bit 48 */
@@ -104,7 +108,6 @@ struct ibs_op_sample {
 */
 static void clear_ibs_nmi(void);
 
-static unsigned long reset_value[NUM_COUNTERS];
 static int ibs_allowed; /* AMD Family10h and later */
 
 struct op_ibs_config {
@@ -118,6 +121,8 @@ struct op_ibs_config {
 
 static struct op_ibs_config ibs_config;
 
+#endif
+
 /* functions for op_amd_spec */
 
 static void op_amd_fill_in_addresses(struct op_msrs * const msrs)
@@ -188,6 +193,8 @@ static void op_amd_setup_ctrs(struct op_msrs const * const msrs)
         }
 }
 
+#ifdef CONFIG_OPROFILE_IBS
+
 static inline int
 op_amd_handle_ibs(struct pt_regs * const regs,
                   struct op_msrs const * const msrs)
@@ -261,6 +268,8 @@ op_amd_handle_ibs(struct pt_regs * const regs,
         return 1;
 }
 
+#endif
+
 static int op_amd_check_ctrs(struct pt_regs * const regs,
                              struct op_msrs const * const msrs)
 {
@@ -277,7 +286,9 @@ static int op_amd_check_ctrs(struct pt_regs * const regs,
                 }
         }
 
+#ifdef CONFIG_OPROFILE_IBS
         op_amd_handle_ibs(regs, msrs);
+#endif
 
         /* See op_model_ppro.c */
         return 1;
@@ -294,6 +305,8 @@ static void op_amd_start(struct op_msrs const * const msrs)
                         CTRL_WRITE(low, high, msrs, i);
                 }
         }
+
+#ifdef CONFIG_OPROFILE_IBS
         if (ibs_allowed && ibs_config.fetch_enabled) {
                 low = (ibs_config.max_cnt_fetch >> 4) & 0xFFFF;
                 high = IBS_FETCH_HIGH_ENABLE;
@@ -305,6 +318,7 @@ static void op_amd_start(struct op_msrs const * const msrs)
                 high = 0;
                 wrmsr(MSR_AMD64_IBSOPCTL, low, high);
         }
+#endif
 }
 
 
@@ -323,6 +337,7 @@ static void op_amd_stop(struct op_msrs const * const msrs)
                 CTRL_WRITE(low, high, msrs, i);
         }
 
+#ifdef CONFIG_OPROFILE_IBS
         if (ibs_allowed && ibs_config.fetch_enabled) {
                 low = 0;                /* clear max count and enable */
                 high = 0;
@@ -334,6 +349,7 @@ static void op_amd_stop(struct op_msrs const * const msrs)
                 high = 0;
                 wrmsr(MSR_AMD64_IBSOPCTL, low, high);
         }
+#endif
 }
 
 static void op_amd_shutdown(struct op_msrs const * const msrs)
@@ -350,17 +366,10 @@ static void op_amd_shutdown(struct op_msrs const * const msrs)
         }
 }
 
-#ifndef CONFIG_SMP
+#ifndef CONFIG_OPROFILE_IBS
 
 /* no IBS support */
 
-static void setup_ibs(void)
-{
-        ibs_allowed = 0;
-}
-
-static void clear_ibs_nmi(void) {}
-
 static int op_amd_init(struct oprofile_operations *ops)
 {
         return 0;
@@ -441,8 +450,12 @@ static void setup_ibs(void)
         if (!ibs_allowed)
                 return;
 
-        if (pfm_amd64_setup_eilvt())
+        if (pfm_amd64_setup_eilvt()) {
                 ibs_allowed = 0;
+                return;
+        }
+
+        printk(KERN_INFO "oprofile: AMD IBS detected\n");
 }