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Diffstat (limited to 'kernel/trace/trace_hw_branches.c')
-rw-r--r--kernel/trace/trace_hw_branches.c302
1 files changed, 0 insertions, 302 deletions
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
deleted file mode 100644
index 7bfdf4c2347..00000000000
--- a/kernel/trace/trace_hw_branches.c
+++ /dev/null
@@ -1,302 +0,0 @@
-/*
- * h/w branch tracer for x86 based on bts
- *
- * Copyright (C) 2008-2009 Intel Corporation.
- * Markus Metzger <markus.t.metzger@gmail.com>, 2008-2009
- */
-#include <linux/spinlock.h>
-#include <linux/kallsyms.h>
-#include <linux/debugfs.h>
-#include <linux/ftrace.h>
-#include <linux/module.h>
-#include <linux/cpu.h>
-#include <linux/smp.h>
-#include <linux/fs.h>
-
-#include <asm/ds.h>
-
-#include "trace.h"
-#include "trace_output.h"
-
-
-#define SIZEOF_BTS (1 << 13)
-
-/*
- * The tracer lock protects the below per-cpu tracer array.
- * It needs to be held to:
- * - start tracing on all cpus
- * - stop tracing on all cpus
- * - start tracing on a single hotplug cpu
- * - stop tracing on a single hotplug cpu
- * - read the trace from all cpus
- * - read the trace from a single cpu
- */
-static DEFINE_SPINLOCK(bts_tracer_lock);
-static DEFINE_PER_CPU(struct bts_tracer *, tracer);
-static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer);
-
-#define this_tracer per_cpu(tracer, smp_processor_id())
-#define this_buffer per_cpu(buffer, smp_processor_id())
-
-static int __read_mostly trace_hw_branches_enabled;
-static struct trace_array *hw_branch_trace __read_mostly;
-
-
-/*
- * Start tracing on the current cpu.
- * The argument is ignored.
- *
- * pre: bts_tracer_lock must be locked.
- */
-static void bts_trace_start_cpu(void *arg)
-{
- if (this_tracer)
- ds_release_bts(this_tracer);
-
- this_tracer =
- ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS,
- /* ovfl = */ NULL, /* th = */ (size_t)-1,
- BTS_KERNEL);
- if (IS_ERR(this_tracer)) {
- this_tracer = NULL;
- return;
- }
-}
-
-static void bts_trace_start(struct trace_array *tr)
-{
- spin_lock(&bts_tracer_lock);
-
- on_each_cpu(bts_trace_start_cpu, NULL, 1);
- trace_hw_branches_enabled = 1;
-
- spin_unlock(&bts_tracer_lock);
-}
-
-/*
- * Stop tracing on the current cpu.
- * The argument is ignored.
- *
- * pre: bts_tracer_lock must be locked.
- */
-static void bts_trace_stop_cpu(void *arg)
-{
- if (this_tracer) {
- ds_release_bts(this_tracer);
- this_tracer = NULL;
- }
-}
-
-static void bts_trace_stop(struct trace_array *tr)
-{
- spin_lock(&bts_tracer_lock);
-
- trace_hw_branches_enabled = 0;
- on_each_cpu(bts_trace_stop_cpu, NULL, 1);
-
- spin_unlock(&bts_tracer_lock);
-}
-
-static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- unsigned int cpu = (unsigned long)hcpu;
-
- spin_lock(&bts_tracer_lock);
-
- if (!trace_hw_branches_enabled)
- goto out;
-
- switch (action) {
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1);
- break;
- case CPU_DOWN_PREPARE:
- smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1);
- break;
- }
-
- out:
- spin_unlock(&bts_tracer_lock);
- return NOTIFY_DONE;
-}
-
-static struct notifier_block bts_hotcpu_notifier __cpuinitdata = {
- .notifier_call = bts_hotcpu_handler
-};
-
-static int bts_trace_init(struct trace_array *tr)
-{
- hw_branch_trace = tr;
-
- bts_trace_start(tr);
-
- return 0;
-}
-
-static void bts_trace_reset(struct trace_array *tr)
-{
- bts_trace_stop(tr);
-}
-
-static void bts_trace_print_header(struct seq_file *m)
-{
- seq_puts(m, "# CPU# TO <- FROM\n");
-}
-
-static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
-{
- struct trace_entry *entry = iter->ent;
- struct trace_seq *seq = &iter->seq;
- struct hw_branch_entry *it;
- unsigned long symflags = TRACE_ITER_SYM_OFFSET;
-
- trace_assign_type(it, entry);
-
- if (entry->type == TRACE_HW_BRANCHES) {
- if (trace_seq_printf(seq, "%4d ", iter->cpu) &&
- seq_print_ip_sym(seq, it->to, symflags) &&
- trace_seq_printf(seq, "\t <- ") &&
- seq_print_ip_sym(seq, it->from, symflags) &&
- trace_seq_printf(seq, "\n"))
- return TRACE_TYPE_HANDLED;
- return TRACE_TYPE_PARTIAL_LINE;;
- }
- return TRACE_TYPE_UNHANDLED;
-}
-
-void trace_hw_branch(u64 from, u64 to)
-{
- struct trace_array *tr = hw_branch_trace;
- struct ring_buffer_event *event;
- struct hw_branch_entry *entry;
- unsigned long irq1;
- int cpu;
-
- if (unlikely(!tr))
- return;
-
- if (unlikely(!trace_hw_branches_enabled))
- return;
-
- local_irq_save(irq1);
- cpu = raw_smp_processor_id();
- if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
- goto out;
-
- event = trace_buffer_lock_reserve(tr, TRACE_HW_BRANCHES,
- sizeof(*entry), 0, 0);
- if (!event)
- goto out;
- entry = ring_buffer_event_data(event);
- tracing_generic_entry_update(&entry->ent, 0, from);
- entry->ent.type = TRACE_HW_BRANCHES;
- entry->from = from;
- entry->to = to;
- trace_buffer_unlock_commit(tr, event, 0, 0);
-
- out:
- atomic_dec(&tr->data[cpu]->disabled);
- local_irq_restore(irq1);
-}
-
-static void trace_bts_at(const struct bts_trace *trace, void *at)
-{
- struct bts_struct bts;
- int err = 0;
-
- WARN_ON_ONCE(!trace->read);
- if (!trace->read)
- return;
-
- err = trace->read(this_tracer, at, &bts);
- if (err < 0)
- return;
-
- switch (bts.qualifier) {
- case BTS_BRANCH:
- trace_hw_branch(bts.variant.lbr.from, bts.variant.lbr.to);
- break;
- }
-}
-
-/*
- * Collect the trace on the current cpu and write it into the ftrace buffer.
- *
- * pre: bts_tracer_lock must be locked
- */
-static void trace_bts_cpu(void *arg)
-{
- struct trace_array *tr = (struct trace_array *) arg;
- const struct bts_trace *trace;
- unsigned char *at;
-
- if (unlikely(!tr))
- return;
-
- if (unlikely(atomic_read(&tr->data[raw_smp_processor_id()]->disabled)))
- return;
-
- if (unlikely(!this_tracer))
- return;
-
- ds_suspend_bts(this_tracer);
- trace = ds_read_bts(this_tracer);
- if (!trace)
- goto out;
-
- for (at = trace->ds.top; (void *)at < trace->ds.end;
- at += trace->ds.size)
- trace_bts_at(trace, at);
-
- for (at = trace->ds.begin; (void *)at < trace->ds.top;
- at += trace->ds.size)
- trace_bts_at(trace, at);
-
-out:
- ds_resume_bts(this_tracer);
-}
-
-static void trace_bts_prepare(struct trace_iterator *iter)
-{
- spin_lock(&bts_tracer_lock);
-
- on_each_cpu(trace_bts_cpu, iter->tr, 1);
-
- spin_unlock(&bts_tracer_lock);
-}
-
-static void trace_bts_close(struct trace_iterator *iter)
-{
- tracing_reset_online_cpus(iter->tr);
-}
-
-void trace_hw_branch_oops(void)
-{
- spin_lock(&bts_tracer_lock);
-
- trace_bts_cpu(hw_branch_trace);
-
- spin_unlock(&bts_tracer_lock);
-}
-
-struct tracer bts_tracer __read_mostly =
-{
- .name = "hw-branch-tracer",
- .init = bts_trace_init,
- .reset = bts_trace_reset,
- .print_header = bts_trace_print_header,
- .print_line = bts_trace_print_line,
- .start = bts_trace_start,
- .stop = bts_trace_stop,
- .open = trace_bts_prepare,
- .close = trace_bts_close
-};
-
-__init static int init_bts_trace(void)
-{
- register_hotcpu_notifier(&bts_hotcpu_notifier);
- return register_tracer(&bts_tracer);
-}
-device_initcall(init_bts_trace);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 12:05:05 +0000