MIPS: Add perf counter feature
Add CPU feature for standard MIPS r2 performance counters, as determined
by the Config1.PC bit. Both perf_events and oprofile probe this bit, so
lets combine the probing and change both to use cpu_has_perf.
This will also be used for VZ support in KVM to know whether performance
counters exist which can be exposed to guests.
[ralf@linux-mips.org: resolve conflict.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Robert Richter <rric@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: oprofile-list@lists.sf.net
Patchwork: https://patchwork.linux-mips.org/patch/13226/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 7962b25..232b037 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -454,4 +454,8 @@
# define cpu_has_contextconfig (cpu_data[0].options & MIPS_CPU_CTXTC)
#endif
+#ifndef cpu_has_perf
+# define cpu_has_perf (cpu_data[0].options & MIPS_CPU_PERF)
+#endif
+
#endif /* __ASM_CPU_FEATURES_H */
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index ddcb2ab..3971a25 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -408,6 +408,7 @@
#define MIPS_CPU_BADINSTR MBIT_ULL(44) /* CPU has BadInstr register */
#define MIPS_CPU_BADINSTRP MBIT_ULL(45) /* CPU has BadInstrP register */
#define MIPS_CPU_CTXTC MBIT_ULL(46) /* CPU has [X]ConfigContext registers */
+#define MIPS_CPU_PERF MBIT_ULL(47) /* CPU has MIPS performance counters */
/*
* CPU ASE encodings
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 963ce7e..45770d8 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -648,6 +648,8 @@
if (config1 & MIPS_CONF1_MD)
c->ases |= MIPS_ASE_MDMX;
+ if (config1 & MIPS_CONF1_PC)
+ c->options |= MIPS_CPU_PERF;
if (config1 & MIPS_CONF1_WR)
c->options |= MIPS_CPU_WATCH;
if (config1 & MIPS_CONF1_CA)
diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c
index 656769c..302af8c 100644
--- a/arch/mips/kernel/perf_event_mipsxx.c
+++ b/arch/mips/kernel/perf_event_mipsxx.c
@@ -101,8 +101,6 @@
static struct mips_pmu mipspmu;
-#define M_CONFIG1_PC (1 << 4)
-
#define M_PERFCTL_EXL (1 << 0)
#define M_PERFCTL_KERNEL (1 << 1)
#define M_PERFCTL_SUPERVISOR (1 << 2)
@@ -754,7 +752,7 @@
static int __n_counters(void)
{
- if (!(read_c0_config1() & M_CONFIG1_PC))
+ if (!cpu_has_perf)
return 0;
if (!(read_c0_perfctrl0() & M_PERFCTL_MORE))
return 1;
diff --git a/arch/mips/oprofile/op_model_mipsxx.c b/arch/mips/oprofile/op_model_mipsxx.c
index 8f988a6..45cb274 100644
--- a/arch/mips/oprofile/op_model_mipsxx.c
+++ b/arch/mips/oprofile/op_model_mipsxx.c
@@ -269,11 +269,9 @@
return handled;
}
-#define M_CONFIG1_PC (1 << 4)
-
static inline int __n_counters(void)
{
- if (!(read_c0_config1() & M_CONFIG1_PC))
+ if (!cpu_has_perf)
return 0;
if (!(read_c0_perfctrl0() & M_PERFCTL_MORE))
return 1;