/*
* Copyright © 2016 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
#include "../i915_selftest.h"
#include "i915_random.h"
#include "mock_gem_device.h"
#include "mock_engine.h"
static int check_rbtree(struct intel_engine_cs *engine,
const unsigned long *bitmap,
const struct intel_wait *waiters,
const int count)
{
struct intel_breadcrumbs *b = &engine->breadcrumbs;
struct rb_node *rb;
int n;
if (&b->irq_wait->node != rb_first(&b->waiters)) {
pr_err("First waiter does not match first element of wait-tree\n");
return -EINVAL;
}
n = find_first_bit(bitmap, count);
for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
struct intel_wait *w = container_of(rb, typeof(*w), node);
int idx = w - waiters;
if (!test_bit(idx, bitmap)) {
pr_err("waiter[%d, seqno=%d] removed but still in wait-tree\n",
idx, w->seqno);
return -EINVAL;
}
if (n != idx) {
pr_err("waiter[%d, seqno=%d] does not match expected next element in tree [%d]\n",
idx, w->seqno, n);
return -EINVAL;
}
n = find_next_bit(bitmap, count, n + 1);
}
return 0;
}
static int check_completion(struct intel_engine_cs *engine,
const unsigned long *bitmap,
const struct intel_wait *waiters,
const int count)
{
int n;
for (n = 0; n < count; n++) {
if (intel_wait_complete(&waiters[n]) != !!test_bit(n, bitmap))
continue;
pr_err("waiter[%d, seqno=%d] is %s, but expected %s\n",
n, waiters[n].seqno,
intel_wait_complete(&waiters[n]) ? "complete" : "active",
test_bit(n, bitmap) ? "active" : "complete");
return -EINVAL;
}
return 0;
}
static int check_rbtree_empty(struct intel_engine_cs *engine)
{
struct intel_breadcrumbs *b = &engine->breadcrumbs;
if (b->irq_wait) {
pr_err("Empty breadcrumbs still has a waiter\n");
return -EINVAL;
}
if (!RB_EMPTY_ROOT(&b->waiters)) {
pr_err("Empty breadcrumbs, but wait-tree not empty\n");
return -EINVAL;
}
return 0;
}
static int igt_random_insert_remove(void *arg)
{
const u32 seqno_bias = 0x1000;
I915_RND_STATE(prng);
struct intel_engine_cs *engine = arg;
struct intel_wait *waiters;
const int count = 4096;
unsigned int *order;
unsigned long *bitmap;
int err = -ENOMEM;
int n;
mock_engine_reset(engine);
waiters = kvmalloc_array(count, sizeof(*waiters), GFP_KERNEL);
if (!waiters)
goto out_engines;
bitmap = kcalloc(DIV_ROUND_UP(count, BITS_PER_LONG), sizeof(*bitmap),
GFP_KERNEL);
if (!bitmap)
goto out_waiters;
order = i915_random_order(count, &prng);
if (!order)
goto out_bitmap;
for (n = 0; n < count; n++)
intel_wait_init_for_seqno(&waiters[n], seqno_bias + n);
err = check_rbtree(engine, bitmap, waiters, count);
if (err)
goto out_order;
/* Add and remove waiters into the rbtree in random order. At each
* step, we verify that the rbtree is correctly ordered.
*/
for (n = 0; n < count; n++) {
int i = order[n];
intel_engine_add_wait(engine, &waiters[i]);
__set_bit(i, bitmap);
err = check_rbtree(engine, bitmap, waiters, count);
if (err)
goto out_order;
}
i915_random_reorder(order, count, &prng);
for (n = 0; n < count; n++) {
int i = order[n];
intel_engine_remove_wait(engine, &waiters[i]);
__clear_bit(i, bitmap);
err = check_rbtree(engine, bitmap, waiters, count);
if (err)
goto out_order;
}
err = check_rbtree_empty(engine);
out_order:
kfree(order);
out_bitmap:
kfree(bitmap);
out_waiters:
kvfree(waiters);
out_engines:
mock_engine_flush(engine);
return err;
}
static int igt_insert_complete(void *arg)
{
const u32 seqno_bias = 0x1000;
struct intel_engine_cs *engine = arg;
struct intel_wait *waiters;
const int count = 4096;
unsigned long *bitmap;
int err = -ENOMEM;
int n, m;
mock_engine_reset(engine);
waiters = kvmalloc_array(count, sizeof(*waiters), GFP_KERNEL);
if (!waiters)
goto out_engines;
bitmap = kcalloc(DIV_ROUND_UP(count, BITS_PER_LONG), sizeof(*bitmap),
GFP_KERNEL);
if (!bitmap)
goto out_waiters;
for (n = 0; n < count; n++) {
intel_wait_init_for_seqno(&waiters[n], n + seqno_bias);
intel_engine_add_wait(engine, &waiters[n]);
__set_bit(n, bitmap);
}
err = check_rbtree(engine, bitmap, waiters, count);
if (err)
goto out_bitmap;
/* On each step, we advance the seqno so that several waiters are then
* complete (we increase the seqno by increasingly larger values to
* retire more and more waiters at once). All retired waiters should
* be woken and removed from the rbtree, and so that we check.
*/
for (n = 0; n < count; n = m) {
int seqno = 2 * n;
GEM_BUG_ON(find_first_bit(bitmap, count) != n);
if (intel_wait_complete(&waiters[n])) {
pr_err("waiter[%d, seqno=%d] completed too early\n",
n, waiters[n].seqno);
err = -EINVAL;
goto out_bitmap;
}
/* complete the following waiters */
mock_seqno_advance(engine, seqno + seqno_bias);
for (m = n; m <= seqno; m++) {
if (m == count)
break;
GEM_BUG_ON(!test_bit(m, bitmap));
__clear_bit(m, bitmap);
}
intel_engine_remove_wait(engine, &waiters[n]);
RB_CLEAR_NODE(&waiters[n].node);
err = check_rbtree(engine, bitmap, waiters, count);
if (err) {
pr_err("rbtree corrupt after seqno advance to %d\n",
seqno + seqno_bias);
goto out_bitmap;
}
err = check_completion(engine, bitmap, waiters, count);
if (err) {
pr_err("completions after seqno advance to %d failed\n",
seqno + seqno_bias);
goto out_bitmap;
}
}
err = check_rbtree_empty(engine);
out_bitmap:
kfree(bitmap);
out_waiters:
kvfree(waiters);
out_engines:
mock_engine_flush(engine);
return err;
}
struct igt_wakeup {
struct task_struct *tsk;
atomic_t *ready, *set, *done;
struct intel_engine_cs *engine;
unsigned long flags;
#define STOP 0
#define IDLE 1
wait_queue_head_t *wq;
u32 seqno;
};
static bool wait_for_ready(struct igt_wakeup *w)
{
DEFINE_WAIT(ready);
set_bit(IDLE, &w->flags);
if (atomic_dec_and_test(w->done))
wake_up_var(w->done);
if (test_bit(STOP, &w->flags))
goto out;
for (;;) {
prepare_to_wait(w->wq, &ready, TASK_INTERRUPTIBLE);
if (atomic_read(w->ready) == 0)
break;
schedule();
}
finish_wait(w->wq, &ready);
out:
clear_bit(IDLE, &w->flags);
if (atomic_dec_and_test(w->set))
wake_up_var(w->set);
return !test_bit(STOP, &w->flags);
}
static int igt_wakeup_thread(void *arg)
{
struct igt_wakeup *w = arg;
struct intel_wait wait;
while (wait_for_ready(w)) {
GEM_BUG_ON(kthread_should_stop());
intel_wait_init_for_seqno(&wait, w->seqno);
intel_engine_add_wait(w->engine, &wait);
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (i915_seqno_passed(intel_engine_get_seqno(w->engine),
w->seqno))
break;
if (test_bit(STOP, &w->flags)) /* emergency escape */
break;
schedule();
}
intel_engine_remove_wait(w->engine, &wait);
__set_current_state(TASK_RUNNING);
}
return 0;
}
static void igt_wake_all_sync(atomic_t *ready,
atomic_t *set,
atomic_t *done,
wait_queue_head_t *wq,
int count)
{
atomic_set(set, count);
atomic_set(ready, 0);
wake_up_all(wq);
wait_var_event(set, !atomic_read(set));
atomic_set(ready, count);
atomic_set(done, count);
}
static int igt_wakeup(void *arg)
{
I915_RND_STATE(prng);
struct intel_engine_cs *engine = arg;
struct igt_wakeup *waiters;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
const int count = 4096;
const u32 max_seqno = count / 4;
atomic_t ready, set, done;
int err = -ENOMEM;
int n, step;
mock_engine_reset(engine);
waiters = kvmalloc_array(count, sizeof(*waiters), GFP_KERNEL);
if (!waiters)
goto out_engines;
/* Create a large number of threads, each waiting on a random seqno.
* Multiple waiters will be waiting for the same seqno.
*/
atomic_set(&ready, count);
for (n = 0; n < count; n++) {
waiters[n].wq = &wq;
waiters[n].ready = &ready;
waiters[n].set = &set;
waiters[n].done = &done;
waiters[n].engine = engine;
waiters[n].flags = BIT(IDLE);
waiters[n].tsk = kthread_run(igt_wakeup_thread, &waiters[n],
"i915/igt:%d", n);
if (IS_ERR(waiters[n].tsk))
goto out_waiters;
get_task_struct(waiters[n].tsk);
}
for (step = 1; step <= max_seqno; step <<= 1) {
u32 seqno;
/* The waiter threads start paused as we assign them a random
* seqno and reset the engine. Once the engine is reset,
* we signal that the threads may begin their wait upon their
* seqno.
*/
for (n = 0; n < count; n++) {
GEM_BUG_ON(!test_bit(IDLE, &waiters[n].flags));
waiters[n].seqno =
1 + prandom_u32_state(&prng) % max_seqno;
}
mock_seqno_advance(engine, 0);
igt_wake_all_sync(&ready, &set, &done, &wq, count);
/* Simulate the GPU doing chunks of work, with one or more
* seqno appearing to finish at the same time. A random number
* of threads will be waiting upon the update and hopefully be
* woken.
*/
for (seqno = 1; seqno <= max_seqno + step; seqno += step) {
usleep_range(50, 500);
mock_seqno_advance(engine, seqno);
}
GEM_BUG_ON(intel_engine_get_seqno(engine) < 1 + max_seqno);
/* With the seqno now beyond any of the waiting threads, they
* should all be woken, see that they are complete and signal
* that they are ready for the next test. We wait until all
* threads are complete and waiting for us (i.e. not a seqno).
*/
if (!wait_var_event_timeout(&done,
!atomic_read(&done), 10 * HZ)) {
pr_err("Timed out waiting for %d remaining waiters\n",
atomic_read(&done));
err = -ETIMEDOUT;
break;
}
err = check_rbtree_empty(engine);
if (err)
break;
}
out_waiters:
for (n = 0; n < count; n++) {
if (IS_ERR(waiters[n].tsk))
break;
set_bit(STOP, &waiters[n].flags);
}
mock_seqno_advance(engine, INT_MAX); /* wakeup any broken waiters */
igt_wake_all_sync(&ready, &set, &done, &wq, n);
for (n = 0; n < count; n++) {
if (IS_ERR(waiters[n].tsk))
break;
kthread_stop(waiters[n].tsk);
put_task_struct(waiters[n].tsk);
}
kvfree(waiters);
out_engines:
mock_engine_flush(engine);
return err;
}
int intel_breadcrumbs_mock_selftests(void)
{
static const struct i915_subtest tests[] = {
SUBTEST(igt_random_insert_remove),
SUBTEST(igt_insert_complete),
SUBTEST(igt_wakeup),
};
struct drm_i915_private *i915;
int err;
i915 = mock_gem_device();
if (!i915)
return -ENOMEM;
err = i915_subtests(tests, i915->engine[RCS]);
drm_dev_unref(&i915->drm);
return err;
}
