/* SPDX-License-Identifier: MIT */

/*
* Copyright © 2019 Intel Corporation
* Copyright © 2021 Advanced Micro Devices, Inc.
*/

#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/dma-resv.h>

#include "selftest.h"

static struct spinlock fence_lock;

static const char *fence_name(struct dma_fence *f)
{
        return "selftest";
}

static const struct dma_fence_ops fence_ops = {
        .get_driver_name = fence_name,
        .get_timeline_name = fence_name,
};

static struct dma_fence *alloc_fence(void)
{
        struct dma_fence *f;

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

        dma_fence_init(f, &fence_ops, &fence_lock, 0, 0);
        return f;
}

static int sanitycheck(void *arg)
{
        struct dma_resv resv;
        struct dma_fence *f;
        int r;

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

        dma_fence_enable_sw_signaling(f);

        dma_fence_signal(f);
        dma_fence_put(f);

        dma_resv_init(&resv);
        r = dma_resv_lock(&resv, NULL);
        if (r)
                pr_err("Resv locking failed\n");
        else
                dma_resv_unlock(&resv);
        dma_resv_fini(&resv);
        return r;
}

static int test_signaling(void *arg)
{
        enum dma_resv_usage usage = (unsigned long)arg;
        struct dma_resv resv;
        struct dma_fence *f;
        int r;

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

        dma_fence_enable_sw_signaling(f);

        dma_resv_init(&resv);
        r = dma_resv_lock(&resv, NULL);
        if (r) {
                pr_err("Resv locking failed\n");
                goto err_free;
        }

        r = dma_resv_reserve_fences(&resv, 1);
        if (r) {
                pr_err("Resv shared slot allocation failed\n");
                goto err_unlock;
        }

        dma_resv_add_fence(&resv, f, usage);
        if (dma_resv_test_signaled(&resv, usage)) {
                pr_err("Resv unexpectedly signaled\n");
                r = -EINVAL;
                goto err_unlock;
        }
        dma_fence_signal(f);
        if (!dma_resv_test_signaled(&resv, usage)) {
                pr_err("Resv not reporting signaled\n");
                r = -EINVAL;
                goto err_unlock;
        }
err_unlock:
        dma_resv_unlock(&resv);
err_free:
        dma_resv_fini(&resv);
        dma_fence_put(f);
        return r;
}

static int test_for_each(void *arg)
{
        enum dma_resv_usage usage = (unsigned long)arg;
        struct dma_resv_iter cursor;
        struct dma_fence *f, *fence;
        struct dma_resv resv;
        int r;

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

        dma_fence_enable_sw_signaling(f);

        dma_resv_init(&resv);
        r = dma_resv_lock(&resv, NULL);
        if (r) {
                pr_err("Resv locking failed\n");
                goto err_free;
        }

        r = dma_resv_reserve_fences(&resv, 1);
        if (r) {
                pr_err("Resv shared slot allocation failed\n");
                goto err_unlock;
        }

        dma_resv_add_fence(&resv, f, usage);

        r = -ENOENT;
        dma_resv_for_each_fence(&cursor, &resv, usage, fence) {
                if (!r) {
                        pr_err("More than one fence found\n");
                        r = -EINVAL;
                        goto err_unlock;
                }
                if (f != fence) {
                        pr_err("Unexpected fence\n");
                        r = -EINVAL;
                        goto err_unlock;
                }
                if (dma_resv_iter_usage(&cursor) != usage) {
                        pr_err("Unexpected fence usage\n");
                        r = -EINVAL;
                        goto err_unlock;
                }
                r = 0;
        }
        if (r) {
                pr_err("No fence found\n");
                goto err_unlock;
        }
        dma_fence_signal(f);
err_unlock:
        dma_resv_unlock(&resv);
err_free:
        dma_resv_fini(&resv);
        dma_fence_put(f);
        return r;
}

static int test_for_each_unlocked(void *arg)
{
        enum dma_resv_usage usage = (unsigned long)arg;
        struct dma_resv_iter cursor;
        struct dma_fence *f, *fence;
        struct dma_resv resv;
        int r;

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

        dma_fence_enable_sw_signaling(f);

        dma_resv_init(&resv);
        r = dma_resv_lock(&resv, NULL);
        if (r) {
                pr_err("Resv locking failed\n");
                goto err_free;
        }

        r = dma_resv_reserve_fences(&resv, 1);
        if (r) {
                pr_err("Resv shared slot allocation failed\n");
                dma_resv_unlock(&resv);
                goto err_free;
        }

        dma_resv_add_fence(&resv, f, usage);
        dma_resv_unlock(&resv);

        r = -ENOENT;
        dma_resv_iter_begin(&cursor, &resv, usage);
        dma_resv_for_each_fence_unlocked(&cursor, fence) {
                if (!r) {
                        pr_err("More than one fence found\n");
                        r = -EINVAL;
                        goto err_iter_end;
                }
                if (!dma_resv_iter_is_restarted(&cursor)) {
                        pr_err("No restart flag\n");
                        goto err_iter_end;
                }
                if (f != fence) {
                        pr_err("Unexpected fence\n");
                        r = -EINVAL;
                        goto err_iter_end;
                }
                if (dma_resv_iter_usage(&cursor) != usage) {
                        pr_err("Unexpected fence usage\n");
                        r = -EINVAL;
                        goto err_iter_end;
                }

                /* We use r as state here */
                if (r == -ENOENT) {
                        r = -EINVAL;
                        /* That should trigger an restart */
                        cursor.fences = (void*)~0;
                } else if (r == -EINVAL) {
                        r = 0;
                }
        }
        if (r)
                pr_err("No fence found\n");
err_iter_end:
        dma_resv_iter_end(&cursor);
        dma_fence_signal(f);
err_free:
        dma_resv_fini(&resv);
        dma_fence_put(f);
        return r;
}

static int test_get_fences(void *arg)
{
        enum dma_resv_usage usage = (unsigned long)arg;
        struct dma_fence *f, **fences = NULL;
        struct dma_resv resv;
        int r, i;

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

        dma_fence_enable_sw_signaling(f);

        dma_resv_init(&resv);
        r = dma_resv_lock(&resv, NULL);
        if (r) {
                pr_err("Resv locking failed\n");
                goto err_resv;
        }

        r = dma_resv_reserve_fences(&resv, 1);
        if (r) {
                pr_err("Resv shared slot allocation failed\n");
                dma_resv_unlock(&resv);
                goto err_resv;
        }

        dma_resv_add_fence(&resv, f, usage);
        dma_resv_unlock(&resv);

        r = dma_resv_get_fences(&resv, usage, &i, &fences);
        if (r) {
                pr_err("get_fences failed\n");
                goto err_free;
        }

        if (i != 1 || fences[0] != f) {
                pr_err("get_fences returned unexpected fence\n");
                goto err_free;
        }

        dma_fence_signal(f);
err_free:
        while (i--)
                dma_fence_put(fences[i]);
        kfree(fences);
err_resv:
        dma_resv_fini(&resv);
        dma_fence_put(f);
        return r;
}

int dma_resv(void)
{
        static const struct subtest tests[] = {
                SUBTEST(sanitycheck),
                SUBTEST(test_signaling),
                SUBTEST(test_for_each),
                SUBTEST(test_for_each_unlocked),
                SUBTEST(test_get_fences),
        };
        enum dma_resv_usage usage;
        int r;

        spin_lock_init(&fence_lock);
        for (usage = DMA_RESV_USAGE_KERNEL; usage <= DMA_RESV_USAGE_BOOKKEEP;
             ++usage) {
                r = subtests(tests, (void *)(unsigned long)usage);
                if (r)
                        return r;
        }
        return 0;
}