[src/trunk]: src/sys/dev/tprof Enable the cycle counter when a CPU hatches an...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ba60c60aec37
branches:  trunk
changeset: 970632:ba60c60aec37
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Mon Mar 30 11:38:29 2020 +0000

description:
Enable the cycle counter when a CPU hatches and store an estimate of the
frequency in ci_data.cpu_cc_freq.

diffstat:

 sys/arch/aarch64/aarch64/cpu.c    |  27 +++++++++++++++++++++++----
 sys/arch/aarch64/include/armreg.h |   5 ++++-
 sys/dev/tprof/tprof_armv8.c       |  24 +++++-------------------
 3 files changed, 32 insertions(+), 24 deletions(-)

diffs (167 lines):

diff -r 776b90d79584 -r ba60c60aec37 sys/arch/aarch64/aarch64/cpu.c
--- a/sys/arch/aarch64/aarch64/cpu.c    Mon Mar 30 10:42:49 2020 +0000
+++ b/sys/arch/aarch64/aarch64/cpu.c    Mon Mar 30 11:38:29 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: cpu.c,v 1.41 2020/02/15 08:16:10 skrll Exp $ */
+/* $NetBSD: cpu.c,v 1.42 2020/03/30 11:38:29 jmcneill Exp $ */
 
 /*
  * Copyright (c) 2017 Ryo Shimizu <ryo%nerv.org@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: cpu.c,v 1.41 2020/02/15 08:16:10 skrll Exp $");
+__KERNEL_RCSID(1, "$NetBSD: cpu.c,v 1.42 2020/03/30 11:38:29 jmcneill Exp $");
 
 #include "locators.h"
 #include "opt_arm_debug.h"
@@ -46,6 +46,7 @@
 #include <aarch64/armreg.h>
 #include <aarch64/cpu.h>
 #include <aarch64/cpufunc.h>
+#include <aarch64/cpu_counter.h>
 #include <aarch64/machdep.h>
 
 #include <arm/cpu_topology.h>
@@ -64,6 +65,7 @@
 static void cpu_identify(device_t self, struct cpu_info *);
 static void cpu_identify1(device_t self, struct cpu_info *);
 static void cpu_identify2(device_t self, struct cpu_info *);
+static void cpu_init_counter(struct cpu_info *);
 static void cpu_setup_id(struct cpu_info *);
 static void cpu_setup_sysctl(device_t, struct cpu_info *);
 
@@ -107,8 +109,6 @@
 
                ci->ci_cpl = IPL_HIGH;
                ci->ci_cpuid = id;
-               // XXX big.LITTLE
-               ci->ci_data.cpu_cc_freq = cpu_info_store[0].ci_data.cpu_cc_freq;
                /* ci_id is stored by own cpus when hatching */
 
                cpu_info[ncpu] = ci;
@@ -150,6 +150,8 @@
        aarch64_printcacheinfo(dv);
        cpu_identify2(dv, ci);
 
+       cpu_init_counter(ci);
+
        cpu_setup_sysctl(dv, ci);
 }
 
@@ -423,6 +425,21 @@
 }
 
 /*
+ * Enable the performance counter, then estimate frequency for
+ * the current PE and store the result in cpu_cc_freq.
+ */
+static void
+cpu_init_counter(struct cpu_info *ci)
+{
+       reg_pmcr_el0_write(PMCR_E | PMCR_C);
+       reg_pmcntenset_el0_write(PMCNTEN_C);
+
+       const uint32_t prev = cpu_counter32();
+       delay(100000);
+       ci->ci_data.cpu_cc_freq = (cpu_counter32() - prev) * 10;
+}
+
+/*
  * Fill in this CPUs id data.  Must be called from hatched cpus.
  */
 static void
@@ -500,6 +517,8 @@
 
        mutex_exit(&cpu_hatch_lock);
 
+       cpu_init_counter(ci);
+
        intr_cpu_init(ci);
 
 #ifdef FDT
diff -r 776b90d79584 -r ba60c60aec37 sys/arch/aarch64/include/armreg.h
--- a/sys/arch/aarch64/include/armreg.h Mon Mar 30 10:42:49 2020 +0000
+++ b/sys/arch/aarch64/include/armreg.h Mon Mar 30 11:38:29 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: armreg.h,v 1.38 2020/03/06 20:28:26 ryo Exp $ */
+/* $NetBSD: armreg.h,v 1.39 2020/03/30 11:38:29 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -1121,6 +1121,9 @@
 AARCH64REG_WRITE_INLINE(pmcntenclr_el0)
 AARCH64REG_WRITE_INLINE(pmcntenset_el0)
 
+#define        PMCNTEN_C               __BIT(31)       // Enable the cycle counter
+#define        PMCNTEN_P               __BITS(30,0)    // Enable event counter bits
+
 AARCH64REG_READ_INLINE(pmcr_el0)
 AARCH64REG_WRITE_INLINE(pmcr_el0)
 
diff -r 776b90d79584 -r ba60c60aec37 sys/dev/tprof/tprof_armv8.c
--- a/sys/dev/tprof/tprof_armv8.c       Mon Mar 30 10:42:49 2020 +0000
+++ b/sys/dev/tprof/tprof_armv8.c       Mon Mar 30 11:38:29 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: tprof_armv8.c,v 1.4 2018/07/17 00:42:48 christos Exp $ */
+/* $NetBSD: tprof_armv8.c,v 1.5 2020/03/30 11:38:29 jmcneill Exp $ */
 
 /*-
  * Copyright (c) 2018 Jared McNeill <jmcneill%invisible.ca@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tprof_armv8.c,v 1.4 2018/07/17 00:42:48 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tprof_armv8.c,v 1.5 2020/03/30 11:38:29 jmcneill Exp $");
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -86,12 +86,7 @@
 armv8_pmu_start_cpu(void *arg1, void *arg2)
 {
        const uint32_t counter_mask = __BIT(armv8_pmu_counter);
-       uint64_t pmcr, pmevtyper;
-
-       /* Enable performance monitor */
-       pmcr = reg_pmcr_el0_read();
-       pmcr |= PMCR_E;
-       reg_pmcr_el0_write(pmcr);
+       uint64_t pmevtyper;
 
        /* Disable event counter */
        reg_pmcntenclr_el0_write(counter_mask);
@@ -122,18 +117,12 @@
 armv8_pmu_stop_cpu(void *arg1, void *arg2)
 {
        const uint32_t counter_mask = __BIT(armv8_pmu_counter);
-       uint32_t pmcr;
 
        /* Disable overflow interrupts */
        reg_pmintenclr_el1_write(counter_mask);
 
        /* Disable event counter */
        reg_pmcntenclr_el0_write(counter_mask);
-
-       /* Disable performance monitor */
-       pmcr = reg_pmcr_el0_read();
-       pmcr &= ~PMCR_E;
-       reg_pmcr_el0_write(pmcr);
 }
 
 static uint64_t
@@ -226,11 +215,8 @@
        /* Disable interrupts */
        reg_pmintenclr_el1_write(~0U);
 
-       /* Disable counters */
-       reg_pmcntenclr_el0_write(~0U);
-
-       /* Disable performance monitor */
-       reg_pmcr_el0_write(0);
+       /* Disable event counters */
+       reg_pmcntenclr_el0_write(PMCNTEN_P);
 
        return tprof_backend_register("tprof_armv8", &tprof_armv8_pmu_ops,
            TPROF_BACKEND_VERSION);