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/* Copyright 2013-2014 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <trace.h>
#include <timebase.h>
#include <lock.h>
#include <string.h>
#include <stdlib.h>
#include <cpu.h>
#include <device.h>
#include <libfdt.h>
#include <processor.h>
#include <skiboot.h>
#include <opal-api.h>
#define DEBUG_TRACES
#define MAX_SIZE (sizeof(union trace) + 7)
/* Smaller trace buffer for early booting */
#define BOOT_TBUF_SZ 65536
static struct {
struct trace_info trace_info;
char buf[BOOT_TBUF_SZ + MAX_SIZE];
} boot_tracebuf;
void init_boot_tracebuf(struct cpu_thread *boot_cpu)
{
init_lock(&boot_tracebuf.trace_info.lock);
boot_tracebuf.trace_info.tb.mask = BOOT_TBUF_SZ - 1;
boot_tracebuf.trace_info.tb.max_size = MAX_SIZE;
boot_cpu->trace = &boot_tracebuf.trace_info;
}
static size_t tracebuf_extra(void)
{
/* We make room for the largest possible record */
return TBUF_SZ + MAX_SIZE;
}
/* To avoid bloating each entry, repeats are actually specific entries.
* tb->last points to the last (non-repeat) entry. */
static bool handle_repeat(struct tracebuf *tb, const union trace *trace)
{
struct trace_hdr *prev;
struct trace_repeat *rpt;
u32 len;
prev = (void *)tb->buf + be64_to_cpu(tb->last & tb->mask);
if (prev->type != trace->hdr.type
|| prev->len_div_8 != trace->hdr.len_div_8
|| prev->cpu != trace->hdr.cpu)
return false;
len = prev->len_div_8 << 3;
if (memcmp(prev + 1, &trace->hdr + 1, len - sizeof(*prev)) != 0)
return false;
/* If they've consumed prev entry, don't repeat. */
if (be64_to_cpu(tb->last) < be64_to_cpu(tb->start))
return false;
/* OK, it's a duplicate. Do we already have repeat? */
if (be64_to_cpu(tb->last) + len != be64_to_cpu(tb->end)) {
u64 pos = be64_to_cpu(tb->last) + len;
/* FIXME: Reader is not protected from seeing this! */
rpt = (void *)tb->buf + (pos & be64_to_cpu(tb->mask));
assert(pos + rpt->len_div_8*8 == be64_to_cpu(tb->end));
assert(rpt->type == TRACE_REPEAT);
/* If this repeat entry is full, don't repeat. */
if (be16_to_cpu(rpt->num) == 0xFFFF)
return false;
rpt->num = cpu_to_be16(be16_to_cpu(rpt->num) + 1);
rpt->timestamp = trace->hdr.timestamp;
return true;
}
/*
* Generate repeat entry: it's the smallest possible entry, so we
* must have eliminated old entries.
*/
assert(trace->hdr.len_div_8 * 8 >= sizeof(*rpt));
rpt = (void *)tb->buf + be64_to_cpu(tb->end & tb->mask);
rpt->timestamp = trace->hdr.timestamp;
rpt->type = TRACE_REPEAT;
rpt->len_div_8 = sizeof(*rpt) >> 3;
rpt->cpu = trace->hdr.cpu;
rpt->prev_len = trace->hdr.len_div_8 << 3;
rpt->num = cpu_to_be16(1);
lwsync(); /* write barrier: complete repeat record before exposing */
tb->end = cpu_to_be64(be64_to_cpu(tb->end) + sizeof(*rpt));
return true;
}
void trace_add(union trace *trace, u8 type, u16 len)
{
struct trace_info *ti = this_cpu()->trace;
unsigned int tsz;
trace->hdr.type = type;
trace->hdr.len_div_8 = (len + 7) >> 3;
tsz = trace->hdr.len_div_8 << 3;
#ifdef DEBUG_TRACES
assert(tsz >= sizeof(trace->hdr));
assert(tsz <= sizeof(*trace));
assert(trace->hdr.type != TRACE_REPEAT);
assert(trace->hdr.type != TRACE_OVERFLOW);
#endif
/* Skip traces not enabled in the debug descriptor */
if (!((1ul << trace->hdr.type) & debug_descriptor.trace_mask))
return;
trace->hdr.timestamp = cpu_to_be64(mftb());
trace->hdr.cpu = cpu_to_be16(this_cpu()->server_no);
lock(&ti->lock);
/* Throw away old entries before we overwrite them. */
while ((be64_to_cpu(ti->tb.start) + be64_to_cpu(ti->tb.mask) + 1)
< (be64_to_cpu(ti->tb.end) + tsz)) {
struct trace_hdr *hdr;
hdr = (void *)ti->tb.buf +
be64_to_cpu(ti->tb.start & ti->tb.mask);
ti->tb.start = cpu_to_be64(be64_to_cpu(ti->tb.start) +
(hdr->len_div_8 << 3));
}
/* Must update ->start before we rewrite new entries. */
lwsync(); /* write barrier */
/* Check for duplicates... */
if (!handle_repeat(&ti->tb, trace)) {
/* This may go off end, and that's why ti->tb.buf is oversize */
memcpy(ti->tb.buf + be64_to_cpu(ti->tb.end & ti->tb.mask),
trace, tsz);
ti->tb.last = ti->tb.end;
lwsync(); /* write barrier: write entry before exposing */
ti->tb.end = cpu_to_be64(be64_to_cpu(ti->tb.end) + tsz);
}
unlock(&ti->lock);
}
static void trace_add_dt_props(void)
{
unsigned int i;
u64 *prop, tmask;
prop = malloc(sizeof(u64) * 2 * debug_descriptor.num_traces);
for (i = 0; i < debug_descriptor.num_traces; i++) {
prop[i * 2] = cpu_to_fdt64(debug_descriptor.trace_phys[i]);
prop[i * 2 + 1] = cpu_to_fdt64(debug_descriptor.trace_size[i]);
}
dt_add_property(opal_node, "ibm,opal-traces",
prop, sizeof(u64) * 2 * i);
free(prop);
tmask = (uint64_t)&debug_descriptor.trace_mask;
dt_add_property_cells(opal_node, "ibm,opal-trace-mask",
hi32(tmask), lo32(tmask));
}
static void trace_add_desc(struct trace_info *t, uint64_t size)
{
unsigned int i = debug_descriptor.num_traces;
if (i >= DEBUG_DESC_MAX_TRACES) {
prerror("TRACE: Debug descriptor trace list full !\n");
return;
}
debug_descriptor.num_traces++;
debug_descriptor.trace_phys[i] = (uint64_t)&t->tb;
debug_descriptor.trace_tce[i] = 0; /* populated later */
debug_descriptor.trace_size[i] = size;
}
/* Allocate trace buffers once we know memory topology */
void init_trace_buffers(void)
{
struct cpu_thread *t;
struct trace_info *any = &boot_tracebuf.trace_info;
uint64_t size;
/* Boot the boot trace in the debug descriptor */
trace_add_desc(any, sizeof(boot_tracebuf.buf));
/* Allocate a trace buffer for each primary cpu. */
for_each_cpu(t) {
if (t->is_secondary)
continue;
/* Use a 4K alignment for TCE mapping */
size = ALIGN_UP(sizeof(*t->trace) + tracebuf_extra(), 0x1000);
t->trace = local_alloc(t->chip_id, size, 0x1000);
if (t->trace) {
any = t->trace;
memset(t->trace, 0, size);
init_lock(&t->trace->lock);
t->trace->tb.mask = cpu_to_be64(TBUF_SZ - 1);
t->trace->tb.max_size = cpu_to_be32(MAX_SIZE);
trace_add_desc(any, sizeof(t->trace->tb) +
tracebuf_extra());
} else
prerror("TRACE: cpu 0x%x allocation failed\n", t->pir);
}
/* In case any allocations failed, share trace buffers. */
for_each_cpu(t) {
if (!t->is_secondary && !t->trace)
t->trace = any;
}
/* And copy those to the secondaries. */
for_each_cpu(t) {
if (!t->is_secondary)
continue;
t->trace = t->primary->trace;
}
/* Trace node in DT. */
trace_add_dt_props();
}
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