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c22fb3807f
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maarten Lankhorst <dev@mblankhorst.nl> Cc: Nicolai Hähnle <nhaehnle@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161201114711.28697-5-chris@chris-wilson.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
179 lines
3.6 KiB
C
179 lines
3.6 KiB
C
/*
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* Module-based API test facility for ww_mutexes
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, you can access it online at
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* http://www.gnu.org/licenses/gpl-2.0.html.
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*/
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#include <linux/kernel.h>
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#include <linux/completion.h>
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#include <linux/kthread.h>
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#include <linux/module.h>
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#include <linux/ww_mutex.h>
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static DEFINE_WW_CLASS(ww_class);
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struct test_mutex {
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struct work_struct work;
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struct ww_mutex mutex;
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struct completion ready, go, done;
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unsigned int flags;
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};
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#define TEST_MTX_SPIN BIT(0)
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#define TEST_MTX_TRY BIT(1)
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#define TEST_MTX_CTX BIT(2)
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#define __TEST_MTX_LAST BIT(3)
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static void test_mutex_work(struct work_struct *work)
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{
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struct test_mutex *mtx = container_of(work, typeof(*mtx), work);
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complete(&mtx->ready);
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wait_for_completion(&mtx->go);
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if (mtx->flags & TEST_MTX_TRY) {
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while (!ww_mutex_trylock(&mtx->mutex))
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cpu_relax();
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} else {
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ww_mutex_lock(&mtx->mutex, NULL);
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}
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complete(&mtx->done);
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ww_mutex_unlock(&mtx->mutex);
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}
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static int __test_mutex(unsigned int flags)
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{
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#define TIMEOUT (HZ / 16)
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struct test_mutex mtx;
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struct ww_acquire_ctx ctx;
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int ret;
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ww_mutex_init(&mtx.mutex, &ww_class);
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ww_acquire_init(&ctx, &ww_class);
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INIT_WORK_ONSTACK(&mtx.work, test_mutex_work);
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init_completion(&mtx.ready);
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init_completion(&mtx.go);
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init_completion(&mtx.done);
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mtx.flags = flags;
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schedule_work(&mtx.work);
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wait_for_completion(&mtx.ready);
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ww_mutex_lock(&mtx.mutex, (flags & TEST_MTX_CTX) ? &ctx : NULL);
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complete(&mtx.go);
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if (flags & TEST_MTX_SPIN) {
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unsigned long timeout = jiffies + TIMEOUT;
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ret = 0;
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do {
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if (completion_done(&mtx.done)) {
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ret = -EINVAL;
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break;
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}
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cpu_relax();
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} while (time_before(jiffies, timeout));
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} else {
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ret = wait_for_completion_timeout(&mtx.done, TIMEOUT);
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}
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ww_mutex_unlock(&mtx.mutex);
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ww_acquire_fini(&ctx);
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if (ret) {
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pr_err("%s(flags=%x): mutual exclusion failure\n",
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__func__, flags);
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ret = -EINVAL;
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}
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flush_work(&mtx.work);
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destroy_work_on_stack(&mtx.work);
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return ret;
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#undef TIMEOUT
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}
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static int test_mutex(void)
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{
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int ret;
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int i;
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for (i = 0; i < __TEST_MTX_LAST; i++) {
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ret = __test_mutex(i);
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if (ret)
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return ret;
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}
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return 0;
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}
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static int test_aa(void)
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{
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struct ww_mutex mutex;
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struct ww_acquire_ctx ctx;
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int ret;
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ww_mutex_init(&mutex, &ww_class);
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ww_acquire_init(&ctx, &ww_class);
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ww_mutex_lock(&mutex, &ctx);
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if (ww_mutex_trylock(&mutex)) {
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pr_err("%s: trylocked itself!\n", __func__);
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ww_mutex_unlock(&mutex);
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ret = -EINVAL;
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goto out;
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}
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ret = ww_mutex_lock(&mutex, &ctx);
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if (ret != -EALREADY) {
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pr_err("%s: missed deadlock for recursing, ret=%d\n",
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__func__, ret);
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if (!ret)
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ww_mutex_unlock(&mutex);
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ret = -EINVAL;
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goto out;
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}
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ret = 0;
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out:
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ww_mutex_unlock(&mutex);
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ww_acquire_fini(&ctx);
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return ret;
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}
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static int __init test_ww_mutex_init(void)
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{
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int ret;
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ret = test_mutex();
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if (ret)
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return ret;
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ret = test_aa();
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if (ret)
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return ret;
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return 0;
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}
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static void __exit test_ww_mutex_exit(void)
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{
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}
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module_init(test_ww_mutex_init);
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module_exit(test_ww_mutex_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Intel Corporation");
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