/*
 * Copyright © 2017 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 <linux/completion.h>
#include <linux/delay.h>
#include <linux/prime_numbers.h>

#include "../i915_selftest.h"

static int
fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
{
        switch (state) {
        case FENCE_COMPLETE:
                break;

        case FENCE_FREE:
                /* Leave the fence for the caller to free it after testing */
                break;
        }

        return NOTIFY_DONE;
}

static struct i915_sw_fence *alloc_fence(void)
{
        struct i915_sw_fence *fence;

        fence = kmalloc_obj(*fence);
        if (!fence)
                return NULL;

        i915_sw_fence_init(fence, fence_notify);
        return fence;
}

static void free_fence(struct i915_sw_fence *fence)
{
        i915_sw_fence_fini(fence);
        kfree(fence);
}

static int __test_self(struct i915_sw_fence *fence)
{
        if (i915_sw_fence_done(fence))
                return -EINVAL;

        i915_sw_fence_commit(fence);
        if (!i915_sw_fence_done(fence))
                return -EINVAL;

        i915_sw_fence_wait(fence);
        if (!i915_sw_fence_done(fence))
                return -EINVAL;

        return 0;
}

static int test_self(void *arg)
{
        struct i915_sw_fence *fence;
        int ret;

        /* Test i915_sw_fence signaling and completion testing */
        fence = alloc_fence();
        if (!fence)
                return -ENOMEM;

        ret = __test_self(fence);

        free_fence(fence);
        return ret;
}

static int test_dag(void *arg)
{
        struct i915_sw_fence *A, *B, *C;
        int ret = -EINVAL;

        /* Test detection of cycles within the i915_sw_fence graphs */
        if (!IS_ENABLED(CONFIG_DRM_I915_SW_FENCE_CHECK_DAG))
                return 0;

        A = alloc_fence();
        if (!A)
                return -ENOMEM;

        if (i915_sw_fence_await_sw_fence_gfp(A, A, GFP_KERNEL) != -EINVAL) {
                pr_err("recursive cycle not detected (AA)\n");
                goto err_A;
        }

        B = alloc_fence();
        if (!B) {
                ret = -ENOMEM;
                goto err_A;
        }

        i915_sw_fence_await_sw_fence_gfp(A, B, GFP_KERNEL);
        if (i915_sw_fence_await_sw_fence_gfp(B, A, GFP_KERNEL) != -EINVAL) {
                pr_err("single depth cycle not detected (BAB)\n");
                goto err_B;
        }

        C = alloc_fence();
        if (!C) {
                ret = -ENOMEM;
                goto err_B;
        }

        if (i915_sw_fence_await_sw_fence_gfp(B, C, GFP_KERNEL) == -EINVAL) {
                pr_err("invalid cycle detected\n");
                goto err_C;
        }
        if (i915_sw_fence_await_sw_fence_gfp(C, B, GFP_KERNEL) != -EINVAL) {
                pr_err("single depth cycle not detected (CBC)\n");
                goto err_C;
        }
        if (i915_sw_fence_await_sw_fence_gfp(C, A, GFP_KERNEL) != -EINVAL) {
                pr_err("cycle not detected (BA, CB, AC)\n");
                goto err_C;
        }
        if (i915_sw_fence_await_sw_fence_gfp(A, C, GFP_KERNEL) == -EINVAL) {
                pr_err("invalid cycle detected\n");
                goto err_C;
        }

        i915_sw_fence_commit(A);
        i915_sw_fence_commit(B);
        i915_sw_fence_commit(C);

        ret = 0;
        if (!i915_sw_fence_done(C)) {
                pr_err("fence C not done\n");
                ret = -EINVAL;
        }
        if (!i915_sw_fence_done(B)) {
                pr_err("fence B not done\n");
                ret = -EINVAL;
        }
        if (!i915_sw_fence_done(A)) {
                pr_err("fence A not done\n");
                ret = -EINVAL;
        }
err_C:
        free_fence(C);
err_B:
        free_fence(B);
err_A:
        free_fence(A);
        return ret;
}

static int test_AB(void *arg)
{
        struct i915_sw_fence *A, *B;
        int ret;

        /* Test i915_sw_fence (A) waiting on an event source (B) */
        A = alloc_fence();
        if (!A)
                return -ENOMEM;
        B = alloc_fence();
        if (!B) {
                ret = -ENOMEM;
                goto err_A;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(A, B, GFP_KERNEL);
        if (ret < 0)
                goto err_B;
        if (ret == 0) {
                pr_err("Incorrectly reported fence A was complete before await\n");
                ret = -EINVAL;
                goto err_B;
        }

        ret = -EINVAL;
        i915_sw_fence_commit(A);
        if (i915_sw_fence_done(A))
                goto err_B;

        i915_sw_fence_commit(B);
        if (!i915_sw_fence_done(B)) {
                pr_err("Fence B is not done\n");
                goto err_B;
        }

        if (!i915_sw_fence_done(A)) {
                pr_err("Fence A is not done\n");
                goto err_B;
        }

        ret = 0;
err_B:
        free_fence(B);
err_A:
        free_fence(A);
        return ret;
}

static int test_ABC(void *arg)
{
        struct i915_sw_fence *A, *B, *C;
        int ret;

        /* Test a chain of fences, A waits on B who waits on C */
        A = alloc_fence();
        if (!A)
                return -ENOMEM;

        B = alloc_fence();
        if (!B) {
                ret = -ENOMEM;
                goto err_A;
        }

        C = alloc_fence();
        if (!C) {
                ret = -ENOMEM;
                goto err_B;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(A, B, GFP_KERNEL);
        if (ret < 0)
                goto err_C;
        if (ret == 0) {
                pr_err("Incorrectly reported fence B was complete before await\n");
                goto err_C;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(B, C, GFP_KERNEL);
        if (ret < 0)
                goto err_C;
        if (ret == 0) {
                pr_err("Incorrectly reported fence C was complete before await\n");
                goto err_C;
        }

        ret = -EINVAL;
        i915_sw_fence_commit(A);
        if (i915_sw_fence_done(A)) {
                pr_err("Fence A completed early\n");
                goto err_C;
        }

        i915_sw_fence_commit(B);
        if (i915_sw_fence_done(B)) {
                pr_err("Fence B completed early\n");
                goto err_C;
        }

        if (i915_sw_fence_done(A)) {
                pr_err("Fence A completed early (after signaling B)\n");
                goto err_C;
        }

        i915_sw_fence_commit(C);

        ret = 0;
        if (!i915_sw_fence_done(C)) {
                pr_err("Fence C not done\n");
                ret = -EINVAL;
        }
        if (!i915_sw_fence_done(B)) {
                pr_err("Fence B not done\n");
                ret = -EINVAL;
        }
        if (!i915_sw_fence_done(A)) {
                pr_err("Fence A not done\n");
                ret = -EINVAL;
        }
err_C:
        free_fence(C);
err_B:
        free_fence(B);
err_A:
        free_fence(A);
        return ret;
}

static int test_AB_C(void *arg)
{
        struct i915_sw_fence *A, *B, *C;
        int ret = -EINVAL;

        /* Test multiple fences (AB) waiting on a single event (C) */
        A = alloc_fence();
        if (!A)
                return -ENOMEM;

        B = alloc_fence();
        if (!B) {
                ret = -ENOMEM;
                goto err_A;
        }

        C = alloc_fence();
        if (!C) {
                ret = -ENOMEM;
                goto err_B;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(A, C, GFP_KERNEL);
        if (ret < 0)
                goto err_C;
        if (ret == 0) {
                ret = -EINVAL;
                goto err_C;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(B, C, GFP_KERNEL);
        if (ret < 0)
                goto err_C;
        if (ret == 0) {
                ret = -EINVAL;
                goto err_C;
        }

        i915_sw_fence_commit(A);
        i915_sw_fence_commit(B);

        ret = 0;
        if (i915_sw_fence_done(A)) {
                pr_err("Fence A completed early\n");
                ret = -EINVAL;
        }

        if (i915_sw_fence_done(B)) {
                pr_err("Fence B completed early\n");
                ret = -EINVAL;
        }

        i915_sw_fence_commit(C);
        if (!i915_sw_fence_done(C)) {
                pr_err("Fence C not done\n");
                ret = -EINVAL;
        }

        if (!i915_sw_fence_done(B)) {
                pr_err("Fence B not done\n");
                ret = -EINVAL;
        }

        if (!i915_sw_fence_done(A)) {
                pr_err("Fence A not done\n");
                ret = -EINVAL;
        }

err_C:
        free_fence(C);
err_B:
        free_fence(B);
err_A:
        free_fence(A);
        return ret;
}

static int test_C_AB(void *arg)
{
        struct i915_sw_fence *A, *B, *C;
        int ret;

        /* Test multiple event sources (A,B) for a single fence (C) */
        A = alloc_fence();
        if (!A)
                return -ENOMEM;

        B = alloc_fence();
        if (!B) {
                ret = -ENOMEM;
                goto err_A;
        }

        C = alloc_fence();
        if (!C) {
                ret = -ENOMEM;
                goto err_B;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(C, A, GFP_KERNEL);
        if (ret < 0)
                goto err_C;
        if (ret == 0) {
                ret = -EINVAL;
                goto err_C;
        }

        ret = i915_sw_fence_await_sw_fence_gfp(C, B, GFP_KERNEL);
        if (ret < 0)
                goto err_C;
        if (ret == 0) {
                ret = -EINVAL;
                goto err_C;
        }

        ret = 0;
        i915_sw_fence_commit(C);
        if (i915_sw_fence_done(C))
                ret = -EINVAL;

        i915_sw_fence_commit(A);
        i915_sw_fence_commit(B);

        if (!i915_sw_fence_done(A)) {
                pr_err("Fence A not done\n");
                ret = -EINVAL;
        }

        if (!i915_sw_fence_done(B)) {
                pr_err("Fence B not done\n");
                ret = -EINVAL;
        }

        if (!i915_sw_fence_done(C)) {
                pr_err("Fence C not done\n");
                ret = -EINVAL;
        }

err_C:
        free_fence(C);
err_B:
        free_fence(B);
err_A:
        free_fence(A);
        return ret;
}

static int test_chain(void *arg)
{
        int nfences = 4096;
        struct i915_sw_fence **fences;
        int ret, i;

        /* Test a long chain of fences */
        fences = kmalloc_objs(*fences, nfences);
        if (!fences)
                return -ENOMEM;

        for (i = 0; i < nfences; i++) {
                fences[i] = alloc_fence();
                if (!fences[i]) {
                        nfences = i;
                        ret = -ENOMEM;
                        goto err;
                }

                if (i > 0) {
                        ret = i915_sw_fence_await_sw_fence_gfp(fences[i],
                                                               fences[i - 1],
                                                               GFP_KERNEL);
                        if (ret < 0) {
                                nfences = i + 1;
                                goto err;
                        }

                        i915_sw_fence_commit(fences[i]);
                }
        }

        ret = 0;
        for (i = nfences; --i; ) {
                if (i915_sw_fence_done(fences[i])) {
                        if (ret == 0)
                                pr_err("Fence[%d] completed early\n", i);
                        ret = -EINVAL;
                }
        }
        i915_sw_fence_commit(fences[0]);
        for (i = 0; ret == 0 && i < nfences; i++) {
                if (!i915_sw_fence_done(fences[i])) {
                        pr_err("Fence[%d] is not done\n", i);
                        ret = -EINVAL;
                }
        }

err:
        for (i = 0; i < nfences; i++)
                free_fence(fences[i]);
        kfree(fences);
        return ret;
}

struct task_ipc {
        struct work_struct work;
        struct completion started;
        struct i915_sw_fence *in, *out;
        int value;
};

static void task_ipc(struct work_struct *work)
{
        struct task_ipc *ipc = container_of(work, typeof(*ipc), work);

        complete(&ipc->started);

        i915_sw_fence_wait(ipc->in);
        smp_store_mb(ipc->value, 1);
        i915_sw_fence_commit(ipc->out);
}

static int test_ipc(void *arg)
{
        struct task_ipc ipc;
        struct workqueue_struct *wq;
        int ret = 0;

        wq = alloc_workqueue("i1915-selftest", 0, 0);
        if (wq == NULL)
                return -ENOMEM;

        /* Test use of i915_sw_fence as an interprocess signaling mechanism */
        ipc.in = alloc_fence();
        if (!ipc.in) {
                ret = -ENOMEM;
                goto err_work;
        }
        ipc.out = alloc_fence();
        if (!ipc.out) {
                ret = -ENOMEM;
                goto err_in;
        }

        /* use a completion to avoid chicken-and-egg testing */
        init_completion(&ipc.started);

        ipc.value = 0;
        INIT_WORK_ONSTACK(&ipc.work, task_ipc);
        queue_work(wq, &ipc.work);

        wait_for_completion(&ipc.started);

        usleep_range(1000, 2000);
        if (READ_ONCE(ipc.value)) {
                pr_err("worker updated value before i915_sw_fence was signaled\n");
                ret = -EINVAL;
        }

        i915_sw_fence_commit(ipc.in);
        i915_sw_fence_wait(ipc.out);

        if (!READ_ONCE(ipc.value)) {
                pr_err("worker signaled i915_sw_fence before value was posted\n");
                ret = -EINVAL;
        }

        flush_work(&ipc.work);
        destroy_work_on_stack(&ipc.work);
        free_fence(ipc.out);
err_in:
        free_fence(ipc.in);
err_work:
        destroy_workqueue(wq);

        return ret;
}

static int test_timer(void *arg)
{
        unsigned long target, delay;
        struct timed_fence tf;

        preempt_disable();
        timed_fence_init(&tf, target = jiffies);
        if (!i915_sw_fence_done(&tf.fence)) {
                pr_err("Fence with immediate expiration not signaled\n");
                goto err;
        }
        preempt_enable();
        timed_fence_fini(&tf);

        for_each_prime_number(delay, i915_selftest.timeout_jiffies/2) {
                preempt_disable();
                timed_fence_init(&tf, target = jiffies + delay);
                if (i915_sw_fence_done(&tf.fence)) {
                        pr_err("Fence with future expiration (%lu jiffies) already signaled\n", delay);
                        goto err;
                }
                preempt_enable();

                i915_sw_fence_wait(&tf.fence);

                preempt_disable();
                if (!i915_sw_fence_done(&tf.fence)) {
                        pr_err("Fence not signaled after wait\n");
                        goto err;
                }
                if (time_before(jiffies, target)) {
                        pr_err("Fence signaled too early, target=%lu, now=%lu\n",
                               target, jiffies);
                        goto err;
                }
                preempt_enable();
                timed_fence_fini(&tf);
        }

        return 0;

err:
        preempt_enable();
        timed_fence_fini(&tf);
        return -EINVAL;
}

static const char *mock_name(struct dma_fence *fence)
{
        return "mock";
}

static const struct dma_fence_ops mock_fence_ops = {
        .get_driver_name = mock_name,
        .get_timeline_name = mock_name,
};

static DEFINE_SPINLOCK(mock_fence_lock);

static struct dma_fence *alloc_dma_fence(void)
{
        struct dma_fence *dma;

        dma = kmalloc_obj(*dma);
        if (dma)
                dma_fence_init(dma, &mock_fence_ops, &mock_fence_lock, 0, 0);

        return dma;
}

static struct i915_sw_fence *
wrap_dma_fence(struct dma_fence *dma, unsigned long delay)
{
        struct i915_sw_fence *fence;
        int err;

        fence = alloc_fence();
        if (!fence)
                return ERR_PTR(-ENOMEM);

        err = i915_sw_fence_await_dma_fence(fence, dma, delay, GFP_NOWAIT);
        i915_sw_fence_commit(fence);
        if (err < 0) {
                free_fence(fence);
                return ERR_PTR(err);
        }

        return fence;
}

static int test_dma_fence(void *arg)
{
        struct i915_sw_fence *timeout = NULL, *not = NULL;
        unsigned long delay = i915_selftest.timeout_jiffies;
        unsigned long end, sleep;
        struct dma_fence *dma;
        int err;

        dma = alloc_dma_fence();
        if (!dma)
                return -ENOMEM;

        timeout = wrap_dma_fence(dma, delay);
        if (IS_ERR(timeout)) {
                err = PTR_ERR(timeout);
                goto err;
        }

        not = wrap_dma_fence(dma, 0);
        if (IS_ERR(not)) {
                err = PTR_ERR(not);
                goto err;
        }

        err = -EINVAL;
        if (i915_sw_fence_done(timeout) || i915_sw_fence_done(not)) {
                pr_err("Fences immediately signaled\n");
                goto err;
        }

        /* We round the timeout for the fence up to the next second */
        end = round_jiffies_up(jiffies + delay);

        sleep = jiffies_to_usecs(delay) / 3;
        usleep_range(sleep, 2 * sleep);
        if (time_after(jiffies, end)) {
                pr_debug("Slept too long, delay=%lu, (target=%lu, now=%lu) skipping\n",
                         delay, end, jiffies);
                goto skip;
        }

        if (i915_sw_fence_done(timeout) || i915_sw_fence_done(not)) {
                pr_err("Fences signaled too early\n");
                goto err;
        }

        if (!wait_event_timeout(timeout->wait,
                                i915_sw_fence_done(timeout),
                                2 * (end - jiffies) + 1)) {
                pr_err("Timeout fence unsignaled!\n");
                goto err;
        }

        if (i915_sw_fence_done(not)) {
                pr_err("No timeout fence signaled!\n");
                goto err;
        }

skip:
        dma_fence_signal(dma);

        if (!i915_sw_fence_done(timeout) || !i915_sw_fence_done(not)) {
                pr_err("Fences unsignaled\n");
                goto err;
        }

        free_fence(not);
        free_fence(timeout);
        dma_fence_put(dma);

        return 0;

err:
        dma_fence_signal(dma);
        if (!IS_ERR_OR_NULL(timeout))
                free_fence(timeout);
        if (!IS_ERR_OR_NULL(not))
                free_fence(not);
        dma_fence_put(dma);
        return err;
}

int i915_sw_fence_mock_selftests(void)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(test_self),
                SUBTEST(test_dag),
                SUBTEST(test_AB),
                SUBTEST(test_ABC),
                SUBTEST(test_AB_C),
                SUBTEST(test_C_AB),
                SUBTEST(test_chain),
                SUBTEST(test_ipc),
                SUBTEST(test_timer),
                SUBTEST(test_dma_fence),
        };

        return i915_subtests(tests, NULL);
}