blob: 0c59f66a6fb2ef451de9d835c19a9d0f4707dec0 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2014, Michael Ellerman, IBM Corp.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include "trace.h"
struct trace_buffer *trace_buffer_allocate(u64 size)
{
struct trace_buffer *tb;
if (size < sizeof(*tb)) {
fprintf(stderr, "Error: trace buffer too small\n");
return NULL;
}
tb = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
if (tb == MAP_FAILED) {
perror("mmap");
return NULL;
}
tb->size = size;
tb->tail = tb->data;
tb->overflow = false;
return tb;
}
static bool trace_check_bounds(struct trace_buffer *tb, void *p)
{
return p < ((void *)tb + tb->size);
}
static bool trace_check_alloc(struct trace_buffer *tb, void *p)
{
/*
* If we ever overflowed don't allow any more input. This prevents us
* from dropping a large item and then later logging a small one. The
* buffer should just stop when overflow happened, not be patchy. If
* you're overflowing, make your buffer bigger.
*/
if (tb->overflow)
return false;
if (!trace_check_bounds(tb, p)) {
tb->overflow = true;
return false;
}
return true;
}
static void *trace_alloc(struct trace_buffer *tb, int bytes)
{
void *p, *newtail;
p = tb->tail;
newtail = tb->tail + bytes;
if (!trace_check_alloc(tb, newtail))
return NULL;
tb->tail = newtail;
return p;
}
static struct trace_entry *trace_alloc_entry(struct trace_buffer *tb, int payload_size)
{
struct trace_entry *e;
e = trace_alloc(tb, sizeof(*e) + payload_size);
if (e)
e->length = payload_size;
return e;
}
int trace_log_reg(struct trace_buffer *tb, u64 reg, u64 value)
{
struct trace_entry *e;
u64 *p;
e = trace_alloc_entry(tb, sizeof(reg) + sizeof(value));
if (!e)
return -ENOSPC;
e->type = TRACE_TYPE_REG;
p = (u64 *)e->data;
*p++ = reg;
*p++ = value;
return 0;
}
int trace_log_counter(struct trace_buffer *tb, u64 value)
{
struct trace_entry *e;
u64 *p;
e = trace_alloc_entry(tb, sizeof(value));
if (!e)
return -ENOSPC;
e->type = TRACE_TYPE_COUNTER;
p = (u64 *)e->data;
*p++ = value;
return 0;
}
int trace_log_string(struct trace_buffer *tb, char *str)
{
struct trace_entry *e;
char *p;
int len;
len = strlen(str);
/* We NULL terminate to make printing easier */
e = trace_alloc_entry(tb, len + 1);
if (!e)
return -ENOSPC;
e->type = TRACE_TYPE_STRING;
p = (char *)e->data;
memcpy(p, str, len);
p += len;
*p = '\0';
return 0;
}
int trace_log_indent(struct trace_buffer *tb)
{
struct trace_entry *e;
e = trace_alloc_entry(tb, 0);
if (!e)
return -ENOSPC;
e->type = TRACE_TYPE_INDENT;
return 0;
}
int trace_log_outdent(struct trace_buffer *tb)
{
struct trace_entry *e;
e = trace_alloc_entry(tb, 0);
if (!e)
return -ENOSPC;
e->type = TRACE_TYPE_OUTDENT;
return 0;
}
static void trace_print_header(int seq, int prefix)
{
printf("%*s[%d]: ", prefix, "", seq);
}
static char *trace_decode_reg(int reg)
{
switch (reg) {
case 769: return "SPRN_MMCR2"; break;
case 770: return "SPRN_MMCRA"; break;
case 779: return "SPRN_MMCR0"; break;
case 804: return "SPRN_EBBHR"; break;
case 805: return "SPRN_EBBRR"; break;
case 806: return "SPRN_BESCR"; break;
case 800: return "SPRN_BESCRS"; break;
case 801: return "SPRN_BESCRSU"; break;
case 802: return "SPRN_BESCRR"; break;
case 803: return "SPRN_BESCRRU"; break;
case 771: return "SPRN_PMC1"; break;
case 772: return "SPRN_PMC2"; break;
case 773: return "SPRN_PMC3"; break;
case 774: return "SPRN_PMC4"; break;
case 775: return "SPRN_PMC5"; break;
case 776: return "SPRN_PMC6"; break;
case 780: return "SPRN_SIAR"; break;
case 781: return "SPRN_SDAR"; break;
case 768: return "SPRN_SIER"; break;
}
return NULL;
}
static void trace_print_reg(struct trace_entry *e)
{
u64 *p, *reg, *value;
char *name;
p = (u64 *)e->data;
reg = p++;
value = p;
name = trace_decode_reg(*reg);
if (name)
printf("register %-10s = 0x%016llx\n", name, *value);
else
printf("register %lld = 0x%016llx\n", *reg, *value);
}
static void trace_print_counter(struct trace_entry *e)
{
u64 *value;
value = (u64 *)e->data;
printf("counter = %lld\n", *value);
}
static void trace_print_string(struct trace_entry *e)
{
char *str;
str = (char *)e->data;
puts(str);
}
#define BASE_PREFIX 2
#define PREFIX_DELTA 8
static void trace_print_entry(struct trace_entry *e, int seq, int *prefix)
{
switch (e->type) {
case TRACE_TYPE_REG:
trace_print_header(seq, *prefix);
trace_print_reg(e);
break;
case TRACE_TYPE_COUNTER:
trace_print_header(seq, *prefix);
trace_print_counter(e);
break;
case TRACE_TYPE_STRING:
trace_print_header(seq, *prefix);
trace_print_string(e);
break;
case TRACE_TYPE_INDENT:
trace_print_header(seq, *prefix);
puts("{");
*prefix += PREFIX_DELTA;
break;
case TRACE_TYPE_OUTDENT:
*prefix -= PREFIX_DELTA;
if (*prefix < BASE_PREFIX)
*prefix = BASE_PREFIX;
trace_print_header(seq, *prefix);
puts("}");
break;
default:
trace_print_header(seq, *prefix);
printf("entry @ %p type %d\n", e, e->type);
break;
}
}
void trace_buffer_print(struct trace_buffer *tb)
{
struct trace_entry *e;
int i, prefix;
void *p;
printf("Trace buffer dump:\n");
printf(" address %p \n", tb);
printf(" tail %p\n", tb->tail);
printf(" size %llu\n", tb->size);
printf(" overflow %s\n", tb->overflow ? "TRUE" : "false");
printf(" Content:\n");
p = tb->data;
i = 0;
prefix = BASE_PREFIX;
while (trace_check_bounds(tb, p) && p < tb->tail) {
e = p;
trace_print_entry(e, i, &prefix);
i++;
p = (void *)e + sizeof(*e) + e->length;
}
}
void trace_print_location(struct trace_buffer *tb)
{
printf("Trace buffer 0x%llx bytes @ %p\n", tb->size, tb);
}