kernel_optimize_test/kernel/trace/trace_mmiotrace.c
Pekka Paalanen bd8ac686c7 ftrace: mmiotrace, updates
here is a patch that makes mmiotrace work almost well within the tracing
framework. The patch applies on top of my previous patch. I have my own
output formatting in place now.

Summary of changes:
- fix the NULL dereference that was due to not calling tracing_reset()
- add print_line() callback into struct tracer
- implement print_line() for mmiotrace, producing up-to-spec text
- add my output header, but that is not really called in the right place
- rewrote the main structs in mmiotrace
- added two new trace entry types: TRACE_MMIO_RW and TRACE_MMIO_MAP
- made some functions in trace.c non-static
- check current==NULL in tracing_generic_entry_update()
- fix(?) comparison in trace_seq_printf()

Things seem to work fine except a few issues. Markers (text lines injected
into mmiotrace log) are missing, I did not feel hacking them in before we
have variable length entries. My output header is printed only for 'trace'
file, but not 'trace_pipe'. For some reason, despite my quick fix,
iter->trace is NULL in print_trace_line() when called from 'trace_pipe'
file, which means I don't get proper output formatting.

I only tried by loading nouveau.ko, which just detects the card, and that
is traced fine. I didn't try further. Map, two reads and unmap. Works
perfectly.

I am missing the information about overflows, I'd prefer to have a
counter for lost events. I didn't try, but I guess currently there is no
way of knowning when it overflows?

So, not too far from being fully operational, it seems :-)
And looking at the diffstat, there also is some 700-900 lines of user space
code that just became obsolete.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-24 11:24:53 +02:00

180 lines
4.1 KiB
C

/*
* Memory mapped I/O tracing
*
* Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
*/
#define DEBUG 1
#include <linux/kernel.h>
#include <linux/mmiotrace.h>
#include "trace.h"
static struct trace_array *mmio_trace_array;
static void mmio_reset_data(struct trace_array *tr)
{
int cpu;
tr->time_start = ftrace_now(tr->cpu);
for_each_online_cpu(cpu)
tracing_reset(tr->data[cpu]);
}
static void mmio_trace_init(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
mmio_trace_array = tr;
if (tr->ctrl) {
mmio_reset_data(tr);
enable_mmiotrace();
}
}
static void mmio_trace_reset(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
if (tr->ctrl)
disable_mmiotrace();
mmio_reset_data(tr);
mmio_trace_array = NULL;
}
static void mmio_trace_ctrl_update(struct trace_array *tr)
{
pr_debug("in %s\n", __func__);
if (tr->ctrl) {
mmio_reset_data(tr);
enable_mmiotrace();
} else {
disable_mmiotrace();
}
}
/* XXX: This is not called for trace_pipe file! */
void mmio_print_header(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
trace_seq_printf(s, "VERSION broken 20070824\n");
/* TODO: print /proc/bus/pci/devices contents as PCIDEV lines */
}
static int mmio_print_rw(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
struct mmiotrace_rw *rw = &entry->mmiorw;
struct trace_seq *s = &iter->seq;
unsigned long long t = ns2usecs(entry->t);
unsigned long usec_rem = do_div(t, 1000000ULL);
unsigned secs = (unsigned long)t;
int ret = 1;
switch (entry->mmiorw.opcode) {
case MMIO_READ:
ret = trace_seq_printf(s,
"R %d %lu.%06lu %d 0x%lx 0x%lx 0x%lx %d\n",
rw->width, secs, usec_rem, rw->map_id, rw->phys,
rw->value, rw->pc, entry->pid);
break;
case MMIO_WRITE:
ret = trace_seq_printf(s,
"W %d %lu.%06lu %d 0x%lx 0x%lx 0x%lx %d\n",
rw->width, secs, usec_rem, rw->map_id, rw->phys,
rw->value, rw->pc, entry->pid);
break;
case MMIO_UNKNOWN_OP:
ret = trace_seq_printf(s,
"UNKNOWN %lu.%06lu %d 0x%lx %02x,%02x,%02x 0x%lx %d\n",
secs, usec_rem, rw->map_id, rw->phys,
(rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
(rw->value >> 0) & 0xff, rw->pc, entry->pid);
break;
default:
ret = trace_seq_printf(s, "rw what?\n");
break;
}
if (ret)
return 1;
return 0;
}
static int mmio_print_map(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
struct mmiotrace_map *m = &entry->mmiomap;
struct trace_seq *s = &iter->seq;
unsigned long long t = ns2usecs(entry->t);
unsigned long usec_rem = do_div(t, 1000000ULL);
unsigned secs = (unsigned long)t;
int ret = 1;
switch (entry->mmiorw.opcode) {
case MMIO_PROBE:
ret = trace_seq_printf(s,
"MAP %lu.%06lu %d 0x%lx 0x%lx 0x%lx 0x%lx %d\n",
secs, usec_rem, m->map_id, m->phys, m->virt, m->len,
0UL, entry->pid);
break;
case MMIO_UNPROBE:
ret = trace_seq_printf(s,
"UNMAP %lu.%06lu %d 0x%lx %d\n",
secs, usec_rem, m->map_id, 0UL, entry->pid);
break;
default:
ret = trace_seq_printf(s, "map what?\n");
break;
}
if (ret)
return 1;
return 0;
}
/* return 0 to abort printing without consuming current entry in pipe mode */
static int mmio_print_line(struct trace_iterator *iter)
{
switch (iter->ent->type) {
case TRACE_MMIO_RW:
return mmio_print_rw(iter);
case TRACE_MMIO_MAP:
return mmio_print_map(iter);
default:
return 1; /* ignore unknown entries */
}
}
static struct tracer mmio_tracer __read_mostly =
{
.name = "mmiotrace",
.init = mmio_trace_init,
.reset = mmio_trace_reset,
.open = mmio_print_header,
.ctrl_update = mmio_trace_ctrl_update,
.print_line = mmio_print_line,
};
__init static int init_mmio_trace(void)
{
return register_tracer(&mmio_tracer);
}
device_initcall(init_mmio_trace);
void mmio_trace_rw(struct mmiotrace_rw *rw)
{
struct trace_array *tr = mmio_trace_array;
struct trace_array_cpu *data = tr->data[smp_processor_id()];
__trace_mmiotrace_rw(tr, data, rw);
}
void mmio_trace_mapping(struct mmiotrace_map *map)
{
struct trace_array *tr = mmio_trace_array;
struct trace_array_cpu *data;
preempt_disable();
data = tr->data[smp_processor_id()];
__trace_mmiotrace_map(tr, data, map);
preempt_enable();
}