// SPDX-License-Identifier: MIT

/*
 * Copyright (C) 2022 Advanced Micro Devices, Inc.
 */

#include <linux/dma-fence.h>
#include <linux/dma-fence-array.h>
#include <linux/dma-fence-chain.h>
#include <linux/dma-fence-unwrap.h>

#include "selftest.h"

#define CHAIN_SZ (4 << 10)

struct mock_fence {
        struct dma_fence base;
        spinlock_t lock;
};

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

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

static struct dma_fence *__mock_fence(u64 context, u64 seqno)
{
        struct mock_fence *f;

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

        spin_lock_init(&f->lock);
        dma_fence_init(&f->base, &mock_ops, &f->lock, context, seqno);

        return &f->base;
}

static struct dma_fence *mock_fence(void)
{
        return __mock_fence(dma_fence_context_alloc(1), 1);
}

static struct dma_fence *mock_array(unsigned int num_fences, ...)
{
        struct dma_fence_array *array;
        struct dma_fence **fences;
        va_list valist;
        int i;

        fences = kzalloc_objs(*fences, num_fences);
        if (!fences)
                goto error_put;

        va_start(valist, num_fences);
        for (i = 0; i < num_fences; ++i)
                fences[i] = va_arg(valist, typeof(*fences));
        va_end(valist);

        array = dma_fence_array_create(num_fences, fences,
                                       dma_fence_context_alloc(1),
                                       1, false);
        if (!array)
                goto error_free;
        return &array->base;

error_free:
        kfree(fences);

error_put:
        va_start(valist, num_fences);
        for (i = 0; i < num_fences; ++i)
                dma_fence_put(va_arg(valist, typeof(*fences)));
        va_end(valist);
        return NULL;
}

static struct dma_fence *mock_chain(struct dma_fence *prev,
                                    struct dma_fence *fence)
{
        struct dma_fence_chain *f;

        f = dma_fence_chain_alloc();
        if (!f) {
                dma_fence_put(prev);
                dma_fence_put(fence);
                return NULL;
        }

        dma_fence_chain_init(f, prev, fence, 1);
        return &f->base;
}

static int sanitycheck(void *arg)
{
        struct dma_fence *f, *chain, *array;
        int err = 0;

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

        dma_fence_enable_sw_signaling(f);

        array = mock_array(1, f);
        if (!array)
                return -ENOMEM;

        chain = mock_chain(NULL, array);
        if (!chain)
                return -ENOMEM;

        dma_fence_put(chain);
        return err;
}

static int unwrap_array(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *array;
        struct dma_fence_unwrap iter;
        int err = 0;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = mock_fence();
        if (!f2) {
                dma_fence_put(f1);
                return -ENOMEM;
        }

        dma_fence_enable_sw_signaling(f2);

        array = mock_array(2, f1, f2);
        if (!array)
                return -ENOMEM;

        dma_fence_unwrap_for_each(fence, &iter, array) {
                if (fence == f1) {
                        f1 = NULL;
                } else if (fence == f2) {
                        f2 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f2) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(array);
        return err;
}

static int unwrap_chain(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *chain;
        struct dma_fence_unwrap iter;
        int err = 0;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = mock_fence();
        if (!f2) {
                dma_fence_put(f1);
                return -ENOMEM;
        }

        dma_fence_enable_sw_signaling(f2);

        chain = mock_chain(f1, f2);
        if (!chain)
                return -ENOMEM;

        dma_fence_unwrap_for_each(fence, &iter, chain) {
                if (fence == f1) {
                        f1 = NULL;
                } else if (fence == f2) {
                        f2 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f2) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(chain);
        return err;
}

static int unwrap_chain_array(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *array, *chain;
        struct dma_fence_unwrap iter;
        int err = 0;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = mock_fence();
        if (!f2) {
                dma_fence_put(f1);
                return -ENOMEM;
        }

        dma_fence_enable_sw_signaling(f2);

        array = mock_array(2, f1, f2);
        if (!array)
                return -ENOMEM;

        chain = mock_chain(NULL, array);
        if (!chain)
                return -ENOMEM;

        dma_fence_unwrap_for_each(fence, &iter, chain) {
                if (fence == f1) {
                        f1 = NULL;
                } else if (fence == f2) {
                        f2 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f2) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(chain);
        return err;
}

static int unwrap_merge(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *f3;
        struct dma_fence_unwrap iter;
        int err = 0;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = mock_fence();
        if (!f2) {
                err = -ENOMEM;
                goto error_put_f1;
        }

        dma_fence_enable_sw_signaling(f2);

        f3 = dma_fence_unwrap_merge(f1, f2);
        if (!f3) {
                err = -ENOMEM;
                goto error_put_f2;
        }

        dma_fence_unwrap_for_each(fence, &iter, f3) {
                if (fence == f1) {
                        dma_fence_put(f1);
                        f1 = NULL;
                } else if (fence == f2) {
                        dma_fence_put(f2);
                        f2 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f2) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(f3);
error_put_f2:
        dma_fence_put(f2);
error_put_f1:
        dma_fence_put(f1);
        return err;
}

static int unwrap_merge_duplicate(void *arg)
{
        struct dma_fence *fence, *f1, *f2;
        struct dma_fence_unwrap iter;
        int err = 0;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = dma_fence_unwrap_merge(f1, f1);
        if (!f2) {
                err = -ENOMEM;
                goto error_put_f1;
        }

        dma_fence_unwrap_for_each(fence, &iter, f2) {
                if (fence == f1) {
                        dma_fence_put(f1);
                        f1 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(f2);
error_put_f1:
        dma_fence_put(f1);
        return err;
}

static int unwrap_merge_seqno(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *f3, *f4;
        struct dma_fence_unwrap iter;
        int err = 0;
        u64 ctx[2];

        ctx[0] = dma_fence_context_alloc(1);
        ctx[1] = dma_fence_context_alloc(1);

        f1 = __mock_fence(ctx[1], 1);
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = __mock_fence(ctx[1], 2);
        if (!f2) {
                err = -ENOMEM;
                goto error_put_f1;
        }

        dma_fence_enable_sw_signaling(f2);

        f3 = __mock_fence(ctx[0], 1);
        if (!f3) {
                err = -ENOMEM;
                goto error_put_f2;
        }

        dma_fence_enable_sw_signaling(f3);

        f4 = dma_fence_unwrap_merge(f1, f2, f3);
        if (!f4) {
                err = -ENOMEM;
                goto error_put_f3;
        }

        dma_fence_unwrap_for_each(fence, &iter, f4) {
                if (fence == f3 && f2) {
                        dma_fence_put(f3);
                        f3 = NULL;
                } else if (fence == f2 && !f3) {
                        dma_fence_put(f2);
                        f2 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f2 || f3) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(f4);
error_put_f3:
        dma_fence_put(f3);
error_put_f2:
        dma_fence_put(f2);
error_put_f1:
        dma_fence_put(f1);
        return err;
}

static int unwrap_merge_order(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *a1, *a2, *c1, *c2;
        struct dma_fence_unwrap iter;
        int err = 0;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = mock_fence();
        if (!f2) {
                dma_fence_put(f1);
                return -ENOMEM;
        }

        dma_fence_enable_sw_signaling(f2);

        a1 = mock_array(2, f1, f2);
        if (!a1)
                return -ENOMEM;

        c1 = mock_chain(NULL, dma_fence_get(f1));
        if (!c1)
                goto error_put_a1;

        c2 = mock_chain(c1, dma_fence_get(f2));
        if (!c2)
                goto error_put_a1;

        /*
         * The fences in the chain are the same as in a1 but in oposite order,
         * the dma_fence_merge() function should be able to handle that.
         */
        a2 = dma_fence_unwrap_merge(a1, c2);

        dma_fence_unwrap_for_each(fence, &iter, a2) {
                if (fence == f1) {
                        f1 = NULL;
                        if (!f2)
                                pr_err("Unexpected order!\n");
                } else if (fence == f2) {
                        f2 = NULL;
                        if (f1)
                                pr_err("Unexpected order!\n");
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f2) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(a2);
        return err;

error_put_a1:
        dma_fence_put(a1);
        return -ENOMEM;
}

static int unwrap_merge_complex(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *f3, *f4, *f5;
        struct dma_fence_unwrap iter;
        int err = -ENOMEM;

        f1 = mock_fence();
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = mock_fence();
        if (!f2)
                goto error_put_f1;

        dma_fence_enable_sw_signaling(f2);

        f3 = dma_fence_unwrap_merge(f1, f2);
        if (!f3)
                goto error_put_f2;

        /* The resulting array has the fences in reverse */
        f4 = mock_array(2, dma_fence_get(f2), dma_fence_get(f1));
        if (!f4)
                goto error_put_f3;

        /* Signaled fences should be filtered, the two arrays merged. */
        f5 = dma_fence_unwrap_merge(f3, f4, dma_fence_get_stub());
        if (!f5)
                goto error_put_f4;

        err = 0;
        dma_fence_unwrap_for_each(fence, &iter, f5) {
                if (fence == f1) {
                        dma_fence_put(f1);
                        f1 = NULL;
                } else if (fence == f2) {
                        dma_fence_put(f2);
                        f2 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f2) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(f5);
error_put_f4:
        dma_fence_put(f4);
error_put_f3:
        dma_fence_put(f3);
error_put_f2:
        dma_fence_put(f2);
error_put_f1:
        dma_fence_put(f1);
        return err;
}

static int unwrap_merge_complex_seqno(void *arg)
{
        struct dma_fence *fence, *f1, *f2, *f3, *f4, *f5, *f6, *f7;
        struct dma_fence_unwrap iter;
        int err = -ENOMEM;
        u64 ctx[2];

        ctx[0] = dma_fence_context_alloc(1);
        ctx[1] = dma_fence_context_alloc(1);

        f1 = __mock_fence(ctx[0], 2);
        if (!f1)
                return -ENOMEM;

        dma_fence_enable_sw_signaling(f1);

        f2 = __mock_fence(ctx[1], 1);
        if (!f2)
                goto error_put_f1;

        dma_fence_enable_sw_signaling(f2);

        f3 = __mock_fence(ctx[0], 1);
        if (!f3)
                goto error_put_f2;

        dma_fence_enable_sw_signaling(f3);

        f4 = __mock_fence(ctx[1], 2);
        if (!f4)
                goto error_put_f3;

        dma_fence_enable_sw_signaling(f4);

        f5 = mock_array(2, dma_fence_get(f1), dma_fence_get(f2));
        if (!f5)
                goto error_put_f4;

        f6 = mock_array(2, dma_fence_get(f3), dma_fence_get(f4));
        if (!f6)
                goto error_put_f5;

        f7 = dma_fence_unwrap_merge(f5, f6);
        if (!f7)
                goto error_put_f6;

        err = 0;
        dma_fence_unwrap_for_each(fence, &iter, f7) {
                if (fence == f1 && f4) {
                        dma_fence_put(f1);
                        f1 = NULL;
                } else if (fence == f4 && !f1) {
                        dma_fence_put(f4);
                        f4 = NULL;
                } else {
                        pr_err("Unexpected fence!\n");
                        err = -EINVAL;
                }
        }

        if (f1 || f4) {
                pr_err("Not all fences seen!\n");
                err = -EINVAL;
        }

        dma_fence_put(f7);
error_put_f6:
        dma_fence_put(f6);
error_put_f5:
        dma_fence_put(f5);
error_put_f4:
        dma_fence_put(f4);
error_put_f3:
        dma_fence_put(f3);
error_put_f2:
        dma_fence_put(f2);
error_put_f1:
        dma_fence_put(f1);
        return err;
}

int dma_fence_unwrap(void)
{
        static const struct subtest tests[] = {
                SUBTEST(sanitycheck),
                SUBTEST(unwrap_array),
                SUBTEST(unwrap_chain),
                SUBTEST(unwrap_chain_array),
                SUBTEST(unwrap_merge),
                SUBTEST(unwrap_merge_duplicate),
                SUBTEST(unwrap_merge_seqno),
                SUBTEST(unwrap_merge_order),
                SUBTEST(unwrap_merge_complex),
                SUBTEST(unwrap_merge_complex_seqno),
        };

        return subtests(tests, NULL);
}