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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/oprofile/nmi_timer_int.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/oprofile/nmi_timer_int.c')
-rw-r--r-- | drivers/oprofile/nmi_timer_int.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/oprofile/nmi_timer_int.c b/drivers/oprofile/nmi_timer_int.c new file mode 100644 index 000000000..f343bd966 --- /dev/null +++ b/drivers/oprofile/nmi_timer_int.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0 +/** + * @file nmi_timer_int.c + * + * @remark Copyright 2011 Advanced Micro Devices, Inc. + * + * @author Robert Richter <robert.richter@amd.com> + */ + +#include <linux/init.h> +#include <linux/smp.h> +#include <linux/errno.h> +#include <linux/oprofile.h> +#include <linux/perf_event.h> + +#ifdef CONFIG_OPROFILE_NMI_TIMER + +static DEFINE_PER_CPU(struct perf_event *, nmi_timer_events); +static int ctr_running; + +static struct perf_event_attr nmi_timer_attr = { + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + .size = sizeof(struct perf_event_attr), + .pinned = 1, + .disabled = 1, +}; + +static void nmi_timer_callback(struct perf_event *event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + event->hw.interrupts = 0; /* don't throttle interrupts */ + oprofile_add_sample(regs, 0); +} + +static int nmi_timer_start_cpu(int cpu) +{ + struct perf_event *event = per_cpu(nmi_timer_events, cpu); + + if (!event) { + event = perf_event_create_kernel_counter(&nmi_timer_attr, cpu, NULL, + nmi_timer_callback, NULL); + if (IS_ERR(event)) + return PTR_ERR(event); + per_cpu(nmi_timer_events, cpu) = event; + } + + if (event && ctr_running) + perf_event_enable(event); + + return 0; +} + +static void nmi_timer_stop_cpu(int cpu) +{ + struct perf_event *event = per_cpu(nmi_timer_events, cpu); + + if (event && ctr_running) + perf_event_disable(event); +} + +static int nmi_timer_cpu_online(unsigned int cpu) +{ + nmi_timer_start_cpu(cpu); + return 0; +} +static int nmi_timer_cpu_predown(unsigned int cpu) +{ + nmi_timer_stop_cpu(cpu); + return 0; +} + +static int nmi_timer_start(void) +{ + int cpu; + + get_online_cpus(); + ctr_running = 1; + for_each_online_cpu(cpu) + nmi_timer_start_cpu(cpu); + put_online_cpus(); + + return 0; +} + +static void nmi_timer_stop(void) +{ + int cpu; + + get_online_cpus(); + for_each_online_cpu(cpu) + nmi_timer_stop_cpu(cpu); + ctr_running = 0; + put_online_cpus(); +} + +static enum cpuhp_state hp_online; + +static void nmi_timer_shutdown(void) +{ + struct perf_event *event; + int cpu; + + cpuhp_remove_state(hp_online); + for_each_possible_cpu(cpu) { + event = per_cpu(nmi_timer_events, cpu); + if (!event) + continue; + perf_event_disable(event); + per_cpu(nmi_timer_events, cpu) = NULL; + perf_event_release_kernel(event); + } +} + +static int nmi_timer_setup(void) +{ + int err; + u64 period; + + /* clock cycles per tick: */ + period = (u64)cpu_khz * 1000; + do_div(period, HZ); + nmi_timer_attr.sample_period = period; + + err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "oprofile/nmi:online", + nmi_timer_cpu_online, nmi_timer_cpu_predown); + if (err < 0) { + nmi_timer_shutdown(); + return err; + } + hp_online = err; + return 0; +} + +int __init op_nmi_timer_init(struct oprofile_operations *ops) +{ + int err = 0; + + err = nmi_timer_setup(); + if (err) + return err; + nmi_timer_shutdown(); /* only check, don't alloc */ + + ops->create_files = NULL; + ops->setup = nmi_timer_setup; + ops->shutdown = nmi_timer_shutdown; + ops->start = nmi_timer_start; + ops->stop = nmi_timer_stop; + ops->cpu_type = "timer"; + + printk(KERN_INFO "oprofile: using NMI timer interrupt.\n"); + + return 0; +} + +#endif |