// SPDX-License-Identifier: GPL-2.0-only
/*
 * Test cases for the drm_mm range manager
 */

#define pr_fmt(fmt) "drm_mm: " fmt

#include <linux/module.h>
#include <linux/prime_numbers.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/vmalloc.h>
#include <linux/ktime.h>

#include <drm/drm_mm.h>

#include "../lib/drm_random.h"

#define TESTS "drm_mm_selftests.h"
#include "drm_selftest.h"

static unsigned int random_seed;
static unsigned int max_iterations = 8192;
static unsigned int max_prime = 128;

enum {
        BEST,
        BOTTOMUP,
        TOPDOWN,
        EVICT,
};

static const struct insert_mode {
        const char *name;
        enum drm_mm_insert_mode mode;
} insert_modes[] = {
        [BEST] = { "best", DRM_MM_INSERT_BEST },
        [BOTTOMUP] = { "bottom-up", DRM_MM_INSERT_LOW },
        [TOPDOWN] = { "top-down", DRM_MM_INSERT_HIGH },
        [EVICT] = { "evict", DRM_MM_INSERT_EVICT },
        {}
}, evict_modes[] = {
        { "bottom-up", DRM_MM_INSERT_LOW },
        { "top-down", DRM_MM_INSERT_HIGH },
        {}
};

static int igt_sanitycheck(void *ignored)
{
        pr_info("%s - ok!\n", __func__);
        return 0;
}

static bool assert_no_holes(const struct drm_mm *mm)
{
        struct drm_mm_node *hole;
        u64 hole_start, __always_unused hole_end;
        unsigned long count;

        count = 0;
        drm_mm_for_each_hole(hole, mm, hole_start, hole_end)
                count++;
        if (count) {
                pr_err("Expected to find no holes (after reserve), found %lu instead\n", count);
                return false;
        }

        drm_mm_for_each_node(hole, mm) {
                if (drm_mm_hole_follows(hole)) {
                        pr_err("Hole follows node, expected none!\n");
                        return false;
                }
        }

        return true;
}

static bool assert_one_hole(const struct drm_mm *mm, u64 start, u64 end)
{
        struct drm_mm_node *hole;
        u64 hole_start, hole_end;
        unsigned long count;
        bool ok = true;

        if (end <= start)
                return true;

        count = 0;
        drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
                if (start != hole_start || end != hole_end) {
                        if (ok)
                                pr_err("empty mm has incorrect hole, found (%llx, %llx), expect (%llx, %llx)\n",
                                       hole_start, hole_end,
                                       start, end);
                        ok = false;
                }
                count++;
        }
        if (count != 1) {
                pr_err("Expected to find one hole, found %lu instead\n", count);
                ok = false;
        }

        return ok;
}

static bool assert_continuous(const struct drm_mm *mm, u64 size)
{
        struct drm_mm_node *node, *check, *found;
        unsigned long n;
        u64 addr;

        if (!assert_no_holes(mm))
                return false;

        n = 0;
        addr = 0;
        drm_mm_for_each_node(node, mm) {
                if (node->start != addr) {
                        pr_err("node[%ld] list out of order, expected %llx found %llx\n",
                               n, addr, node->start);
                        return false;
                }

                if (node->size != size) {
                        pr_err("node[%ld].size incorrect, expected %llx, found %llx\n",
                               n, size, node->size);
                        return false;
                }

                if (drm_mm_hole_follows(node)) {
                        pr_err("node[%ld] is followed by a hole!\n", n);
                        return false;
                }

                found = NULL;
                drm_mm_for_each_node_in_range(check, mm, addr, addr + size) {
                        if (node != check) {
                                pr_err("lookup return wrong node, expected start %llx, found %llx\n",
                                       node->start, check->start);
                                return false;
                        }
                        found = check;
                }
                if (!found) {
                        pr_err("lookup failed for node %llx + %llx\n",
                               addr, size);
                        return false;
                }

                addr += size;
                n++;
        }

        return true;
}

static u64 misalignment(struct drm_mm_node *node, u64 alignment)
{
        u64 rem;

        if (!alignment)
                return 0;

        div64_u64_rem(node->start, alignment, &rem);
        return rem;
}

static bool assert_node(struct drm_mm_node *node, struct drm_mm *mm,
                        u64 size, u64 alignment, unsigned long color)
{
        bool ok = true;

        if (!drm_mm_node_allocated(node) || node->mm != mm) {
                pr_err("node not allocated\n");
                ok = false;
        }

        if (node->size != size) {
                pr_err("node has wrong size, found %llu, expected %llu\n",
                       node->size, size);
                ok = false;
        }

        if (misalignment(node, alignment)) {
                pr_err("node is misaligned, start %llx rem %llu, expected alignment %llu\n",
                       node->start, misalignment(node, alignment), alignment);
                ok = false;
        }

        if (node->color != color) {
                pr_err("node has wrong color, found %lu, expected %lu\n",
                       node->color, color);
                ok = false;
        }

        return ok;
}

#define show_mm(mm) do { \
        struct drm_printer __p = drm_debug_printer(__func__); \
        drm_mm_print((mm), &__p); } while (0)

static int igt_init(void *ignored)
{
        const unsigned int size = 4096;
        struct drm_mm mm;
        struct drm_mm_node tmp;
        int ret = -EINVAL;

        /* Start with some simple checks on initialising the struct drm_mm */
        memset(&mm, 0, sizeof(mm));
        if (drm_mm_initialized(&mm)) {
                pr_err("zeroed mm claims to be initialized\n");
                return ret;
        }

        memset(&mm, 0xff, sizeof(mm));
        drm_mm_init(&mm, 0, size);
        if (!drm_mm_initialized(&mm)) {
                pr_err("mm claims not to be initialized\n");
                goto out;
        }

        if (!drm_mm_clean(&mm)) {
                pr_err("mm not empty on creation\n");
                goto out;
        }

        /* After creation, it should all be one massive hole */
        if (!assert_one_hole(&mm, 0, size)) {
                ret = -EINVAL;
                goto out;
        }

        memset(&tmp, 0, sizeof(tmp));
        tmp.start = 0;
        tmp.size = size;
        ret = drm_mm_reserve_node(&mm, &tmp);
        if (ret) {
                pr_err("failed to reserve whole drm_mm\n");
                goto out;
        }

        /* After filling the range entirely, there should be no holes */
        if (!assert_no_holes(&mm)) {
                ret = -EINVAL;
                goto out;
        }

        /* And then after emptying it again, the massive hole should be back */
        drm_mm_remove_node(&tmp);
        if (!assert_one_hole(&mm, 0, size)) {
                ret = -EINVAL;
                goto out;
        }

out:
        if (ret)
                show_mm(&mm);
        drm_mm_takedown(&mm);
        return ret;
}

static int igt_debug(void *ignored)
{
        struct drm_mm mm;
        struct drm_mm_node nodes[2];
        int ret;

        /* Create a small drm_mm with a couple of nodes and a few holes, and
         * check that the debug iterator doesn't explode over a trivial drm_mm.
         */

        drm_mm_init(&mm, 0, 4096);

        memset(nodes, 0, sizeof(nodes));
        nodes[0].start = 512;
        nodes[0].size = 1024;
        ret = drm_mm_reserve_node(&mm, &nodes[0]);
        if (ret) {
                pr_err("failed to reserve node[0] {start=%lld, size=%lld)\n",
                       nodes[0].start, nodes[0].size);
                return ret;
        }

        nodes[1].size = 1024;
        nodes[1].start = 4096 - 512 - nodes[1].size;
        ret = drm_mm_reserve_node(&mm, &nodes[1]);
        if (ret) {
                pr_err("failed to reserve node[1] {start=%lld, size=%lld)\n",
                       nodes[1].start, nodes[1].size);
                return ret;
        }

        show_mm(&mm);
        return 0;
}

static struct drm_mm_node *set_node(struct drm_mm_node *node,
                                    u64 start, u64 size)
{
        node->start = start;
        node->size = size;
        return node;
}

static bool expect_reserve_fail(struct drm_mm *mm, struct drm_mm_node *node)
{
        int err;

        err = drm_mm_reserve_node(mm, node);
        if (likely(err == -ENOSPC))
                return true;

        if (!err) {
                pr_err("impossible reserve succeeded, node %llu + %llu\n",
                       node->start, node->size);
                drm_mm_remove_node(node);
        } else {
                pr_err("impossible reserve failed with wrong error %d [expected %d], node %llu + %llu\n",
                       err, -ENOSPC, node->start, node->size);
        }
        return false;
}

static bool check_reserve_boundaries(struct drm_mm *mm,
                                     unsigned int count,
                                     u64 size)
{
        const struct boundary {
                u64 start, size;
                const char *name;
        } boundaries[] = {
#define B(st, sz) { (st), (sz), "{ " #st ", " #sz "}" }
                B(0, 0),
                B(-size, 0),
                B(size, 0),
                B(size * count, 0),
                B(-size, size),
                B(-size, -size),
                B(-size, 2*size),
                B(0, -size),
                B(size, -size),
                B(count*size, size),
                B(count*size, -size),
                B(count*size, count*size),
                B(count*size, -count*size),
                B(count*size, -(count+1)*size),
                B((count+1)*size, size),
                B((count+1)*size, -size),
                B((count+1)*size, -2*size),
#undef B
        };
        struct drm_mm_node tmp = {};
        int n;

        for (n = 0; n < ARRAY_SIZE(boundaries); n++) {
                if (!expect_reserve_fail(mm,
                                         set_node(&tmp,
                                                  boundaries[n].start,
                                                  boundaries[n].size))) {
                        pr_err("boundary[%d:%s] failed, count=%u, size=%lld\n",
                               n, boundaries[n].name, count, size);
                        return false;
                }
        }

        return true;
}

static int __igt_reserve(unsigned int count, u64 size)
{
        DRM_RND_STATE(prng, random_seed);
        struct drm_mm mm;
        struct drm_mm_node tmp, *nodes, *node, *next;
        unsigned int *order, n, m, o = 0;
        int ret, err;

        /* For exercising drm_mm_reserve_node(), we want to check that
         * reservations outside of the drm_mm range are rejected, and to
         * overlapping and otherwise already occupied ranges. Afterwards,
         * the tree and nodes should be intact.
         */

        DRM_MM_BUG_ON(!count);
        DRM_MM_BUG_ON(!size);

        ret = -ENOMEM;
        order = drm_random_order(count, &prng);
        if (!order)
                goto err;

        nodes = vzalloc(array_size(count, sizeof(*nodes)));
        if (!nodes)
                goto err_order;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, count * size);

        if (!check_reserve_boundaries(&mm, count, size))
                goto out;

        for (n = 0; n < count; n++) {
                nodes[n].start = order[n] * size;
                nodes[n].size = size;

                err = drm_mm_reserve_node(&mm, &nodes[n]);
                if (err) {
                        pr_err("reserve failed, step %d, start %llu\n",
                               n, nodes[n].start);
                        ret = err;
                        goto out;
                }

                if (!drm_mm_node_allocated(&nodes[n])) {
                        pr_err("reserved node not allocated! step %d, start %llu\n",
                               n, nodes[n].start);
                        goto out;
                }

                if (!expect_reserve_fail(&mm, &nodes[n]))
                        goto out;
        }

        /* After random insertion the nodes should be in order */
        if (!assert_continuous(&mm, size))
                goto out;

        /* Repeated use should then fail */
        drm_random_reorder(order, count, &prng);
        for (n = 0; n < count; n++) {
                if (!expect_reserve_fail(&mm,
                                         set_node(&tmp, order[n] * size, 1)))
                        goto out;

                /* Remove and reinsert should work */
                drm_mm_remove_node(&nodes[order[n]]);
                err = drm_mm_reserve_node(&mm, &nodes[order[n]]);
                if (err) {
                        pr_err("reserve failed, step %d, start %llu\n",
                               n, nodes[n].start);
                        ret = err;
                        goto out;
                }
        }

        if (!assert_continuous(&mm, size))
                goto out;

        /* Overlapping use should then fail */
        for (n = 0; n < count; n++) {
                if (!expect_reserve_fail(&mm, set_node(&tmp, 0, size*count)))
                        goto out;
        }
        for (n = 0; n < count; n++) {
                if (!expect_reserve_fail(&mm,
                                         set_node(&tmp,
                                                  size * n,
                                                  size * (count - n))))
                        goto out;
        }

        /* Remove several, reinsert, check full */
        for_each_prime_number(n, min(max_prime, count)) {
                for (m = 0; m < n; m++) {
                        node = &nodes[order[(o + m) % count]];
                        drm_mm_remove_node(node);
                }

                for (m = 0; m < n; m++) {
                        node = &nodes[order[(o + m) % count]];
                        err = drm_mm_reserve_node(&mm, node);
                        if (err) {
                                pr_err("reserve failed, step %d/%d, start %llu\n",
                                       m, n, node->start);
                                ret = err;
                                goto out;
                        }
                }

                o += n;

                if (!assert_continuous(&mm, size))
                        goto out;
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        vfree(nodes);
err_order:
        kfree(order);
err:
        return ret;
}

static int igt_reserve(void *ignored)
{
        const unsigned int count = min_t(unsigned int, BIT(10), max_iterations);
        int n, ret;

        for_each_prime_number_from(n, 1, 54) {
                u64 size = BIT_ULL(n);

                ret = __igt_reserve(count, size - 1);
                if (ret)
                        return ret;

                ret = __igt_reserve(count, size);
                if (ret)
                        return ret;

                ret = __igt_reserve(count, size + 1);
                if (ret)
                        return ret;

                cond_resched();
        }

        return 0;
}

static bool expect_insert(struct drm_mm *mm, struct drm_mm_node *node,
                          u64 size, u64 alignment, unsigned long color,
                          const struct insert_mode *mode)
{
        int err;

        err = drm_mm_insert_node_generic(mm, node,
                                         size, alignment, color,
                                         mode->mode);
        if (err) {
                pr_err("insert (size=%llu, alignment=%llu, color=%lu, mode=%s) failed with err=%d\n",
                       size, alignment, color, mode->name, err);
                return false;
        }

        if (!assert_node(node, mm, size, alignment, color)) {
                drm_mm_remove_node(node);
                return false;
        }

        return true;
}

static bool expect_insert_fail(struct drm_mm *mm, u64 size)
{
        struct drm_mm_node tmp = {};
        int err;

        err = drm_mm_insert_node(mm, &tmp, size);
        if (likely(err == -ENOSPC))
                return true;

        if (!err) {
                pr_err("impossible insert succeeded, node %llu + %llu\n",
                       tmp.start, tmp.size);
                drm_mm_remove_node(&tmp);
        } else {
                pr_err("impossible insert failed with wrong error %d [expected %d], size %llu\n",
                       err, -ENOSPC, size);
        }
        return false;
}

static int __igt_insert(unsigned int count, u64 size, bool replace)
{
        DRM_RND_STATE(prng, random_seed);
        const struct insert_mode *mode;
        struct drm_mm mm;
        struct drm_mm_node *nodes, *node, *next;
        unsigned int *order, n, m, o = 0;
        int ret;

        /* Fill a range with lots of nodes, check it doesn't fail too early */

        DRM_MM_BUG_ON(!count);
        DRM_MM_BUG_ON(!size);

        ret = -ENOMEM;
        nodes = vmalloc(array_size(count, sizeof(*nodes)));
        if (!nodes)
                goto err;

        order = drm_random_order(count, &prng);
        if (!order)
                goto err_nodes;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, count * size);

        for (mode = insert_modes; mode->name; mode++) {
                for (n = 0; n < count; n++) {
                        struct drm_mm_node tmp;

                        node = replace ? &tmp : &nodes[n];
                        memset(node, 0, sizeof(*node));
                        if (!expect_insert(&mm, node, size, 0, n, mode)) {
                                pr_err("%s insert failed, size %llu step %d\n",
                                       mode->name, size, n);
                                goto out;
                        }

                        if (replace) {
                                drm_mm_replace_node(&tmp, &nodes[n]);
                                if (drm_mm_node_allocated(&tmp)) {
                                        pr_err("replaced old-node still allocated! step %d\n",
                                               n);
                                        goto out;
                                }

                                if (!assert_node(&nodes[n], &mm, size, 0, n)) {
                                        pr_err("replaced node did not inherit parameters, size %llu step %d\n",
                                               size, n);
                                        goto out;
                                }

                                if (tmp.start != nodes[n].start) {
                                        pr_err("replaced node mismatch location expected [%llx + %llx], found [%llx + %llx]\n",
                                               tmp.start, size,
                                               nodes[n].start, nodes[n].size);
                                        goto out;
                                }
                        }
                }

                /* After random insertion the nodes should be in order */
                if (!assert_continuous(&mm, size))
                        goto out;

                /* Repeated use should then fail */
                if (!expect_insert_fail(&mm, size))
                        goto out;

                /* Remove one and reinsert, as the only hole it should refill itself */
                for (n = 0; n < count; n++) {
                        u64 addr = nodes[n].start;

                        drm_mm_remove_node(&nodes[n]);
                        if (!expect_insert(&mm, &nodes[n], size, 0, n, mode)) {
                                pr_err("%s reinsert failed, size %llu step %d\n",
                                       mode->name, size, n);
                                goto out;
                        }

                        if (nodes[n].start != addr) {
                                pr_err("%s reinsert node moved, step %d, expected %llx, found %llx\n",
                                       mode->name, n, addr, nodes[n].start);
                                goto out;
                        }

                        if (!assert_continuous(&mm, size))
                                goto out;
                }

                /* Remove several, reinsert, check full */
                for_each_prime_number(n, min(max_prime, count)) {
                        for (m = 0; m < n; m++) {
                                node = &nodes[order[(o + m) % count]];
                                drm_mm_remove_node(node);
                        }

                        for (m = 0; m < n; m++) {
                                node = &nodes[order[(o + m) % count]];
                                if (!expect_insert(&mm, node, size, 0, n, mode)) {
                                        pr_err("%s multiple reinsert failed, size %llu step %d\n",
                                               mode->name, size, n);
                                        goto out;
                                }
                        }

                        o += n;

                        if (!assert_continuous(&mm, size))
                                goto out;

                        if (!expect_insert_fail(&mm, size))
                                goto out;
                }

                drm_mm_for_each_node_safe(node, next, &mm)
                        drm_mm_remove_node(node);
                DRM_MM_BUG_ON(!drm_mm_clean(&mm));

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

static int igt_insert(void *ignored)
{
        const unsigned int count = min_t(unsigned int, BIT(10), max_iterations);
        unsigned int n;
        int ret;

        for_each_prime_number_from(n, 1, 54) {
                u64 size = BIT_ULL(n);

                ret = __igt_insert(count, size - 1, false);
                if (ret)
                        return ret;

                ret = __igt_insert(count, size, false);
                if (ret)
                        return ret;

                ret = __igt_insert(count, size + 1, false);
                if (ret)
                        return ret;

                cond_resched();
        }

        return 0;
}

static int igt_replace(void *ignored)
{
        const unsigned int count = min_t(unsigned int, BIT(10), max_iterations);
        unsigned int n;
        int ret;

        /* Reuse igt_insert to exercise replacement by inserting a dummy node,
         * then replacing it with the intended node. We want to check that
         * the tree is intact and all the information we need is carried
         * across to the target node.
         */

        for_each_prime_number_from(n, 1, 54) {
                u64 size = BIT_ULL(n);

                ret = __igt_insert(count, size - 1, true);
                if (ret)
                        return ret;

                ret = __igt_insert(count, size, true);
                if (ret)
                        return ret;

                ret = __igt_insert(count, size + 1, true);
                if (ret)
                        return ret;

                cond_resched();
        }

        return 0;
}

static bool expect_insert_in_range(struct drm_mm *mm, struct drm_mm_node *node,
                                   u64 size, u64 alignment, unsigned long color,
                                   u64 range_start, u64 range_end,
                                   const struct insert_mode *mode)
{
        int err;

        err = drm_mm_insert_node_in_range(mm, node,
                                          size, alignment, color,
                                          range_start, range_end,
                                          mode->mode);
        if (err) {
                pr_err("insert (size=%llu, alignment=%llu, color=%lu, mode=%s) nto range [%llx, %llx] failed with err=%d\n",
                       size, alignment, color, mode->name,
                       range_start, range_end, err);
                return false;
        }

        if (!assert_node(node, mm, size, alignment, color)) {
                drm_mm_remove_node(node);
                return false;
        }

        return true;
}

static bool expect_insert_in_range_fail(struct drm_mm *mm,
                                        u64 size,
                                        u64 range_start,
                                        u64 range_end)
{
        struct drm_mm_node tmp = {};
        int err;

        err = drm_mm_insert_node_in_range(mm, &tmp,
                                          size, 0, 0,
                                          range_start, range_end,
                                          0);
        if (likely(err == -ENOSPC))
                return true;

        if (!err) {
                pr_err("impossible insert succeeded, node %llx + %llu, range [%llx, %llx]\n",
                       tmp.start, tmp.size, range_start, range_end);
                drm_mm_remove_node(&tmp);
        } else {
                pr_err("impossible insert failed with wrong error %d [expected %d], size %llu, range [%llx, %llx]\n",
                       err, -ENOSPC, size, range_start, range_end);
        }

        return false;
}

static bool assert_contiguous_in_range(struct drm_mm *mm,
                                       u64 size,
                                       u64 start,
                                       u64 end)
{
        struct drm_mm_node *node;
        unsigned int n;

        if (!expect_insert_in_range_fail(mm, size, start, end))
                return false;

        n = div64_u64(start + size - 1, size);
        drm_mm_for_each_node(node, mm) {
                if (node->start < start || node->start + node->size > end) {
                        pr_err("node %d out of range, address [%llx + %llu], range [%llx, %llx]\n",
                               n, node->start, node->start + node->size, start, end);
                        return false;
                }

                if (node->start != n * size) {
                        pr_err("node %d out of order, expected start %llx, found %llx\n",
                               n, n * size, node->start);
                        return false;
                }

                if (node->size != size) {
                        pr_err("node %d has wrong size, expected size %llx, found %llx\n",
                               n, size, node->size);
                        return false;
                }

                if (drm_mm_hole_follows(node) &&
                    drm_mm_hole_node_end(node) < end) {
                        pr_err("node %d is followed by a hole!\n", n);
                        return false;
                }

                n++;
        }

        if (start > 0) {
                node = __drm_mm_interval_first(mm, 0, start - 1);
                if (drm_mm_node_allocated(node)) {
                        pr_err("node before start: node=%llx+%llu, start=%llx\n",
                               node->start, node->size, start);
                        return false;
                }
        }

        if (end < U64_MAX) {
                node = __drm_mm_interval_first(mm, end, U64_MAX);
                if (drm_mm_node_allocated(node)) {
                        pr_err("node after end: node=%llx+%llu, end=%llx\n",
                               node->start, node->size, end);
                        return false;
                }
        }

        return true;
}

static int __igt_insert_range(unsigned int count, u64 size, u64 start, u64 end)
{
        const struct insert_mode *mode;
        struct drm_mm mm;
        struct drm_mm_node *nodes, *node, *next;
        unsigned int n, start_n, end_n;
        int ret;

        DRM_MM_BUG_ON(!count);
        DRM_MM_BUG_ON(!size);
        DRM_MM_BUG_ON(end <= start);

        /* Very similar to __igt_insert(), but now instead of populating the
         * full range of the drm_mm, we try to fill a small portion of it.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(count, sizeof(*nodes)));
        if (!nodes)
                goto err;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, count * size);

        start_n = div64_u64(start + size - 1, size);
        end_n = div64_u64(end - size, size);

        for (mode = insert_modes; mode->name; mode++) {
                for (n = start_n; n <= end_n; n++) {
                        if (!expect_insert_in_range(&mm, &nodes[n],
                                                    size, size, n,
                                                    start, end, mode)) {
                                pr_err("%s insert failed, size %llu, step %d [%d, %d], range [%llx, %llx]\n",
                                       mode->name, size, n,
                                       start_n, end_n,
                                       start, end);
                                goto out;
                        }
                }

                if (!assert_contiguous_in_range(&mm, size, start, end)) {
                        pr_err("%s: range [%llx, %llx] not full after initialisation, size=%llu\n",
                               mode->name, start, end, size);
                        goto out;
                }

                /* Remove one and reinsert, it should refill itself */
                for (n = start_n; n <= end_n; n++) {
                        u64 addr = nodes[n].start;

                        drm_mm_remove_node(&nodes[n]);
                        if (!expect_insert_in_range(&mm, &nodes[n],
                                                    size, size, n,
                                                    start, end, mode)) {
                                pr_err("%s reinsert failed, step %d\n", mode->name, n);
                                goto out;
                        }

                        if (nodes[n].start != addr) {
                                pr_err("%s reinsert node moved, step %d, expected %llx, found %llx\n",
                                       mode->name, n, addr, nodes[n].start);
                                goto out;
                        }
                }

                if (!assert_contiguous_in_range(&mm, size, start, end)) {
                        pr_err("%s: range [%llx, %llx] not full after reinsertion, size=%llu\n",
                               mode->name, start, end, size);
                        goto out;
                }

                drm_mm_for_each_node_safe(node, next, &mm)
                        drm_mm_remove_node(node);
                DRM_MM_BUG_ON(!drm_mm_clean(&mm));

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        vfree(nodes);
err:
        return ret;
}

static int insert_outside_range(void)
{
        struct drm_mm mm;
        const unsigned int start = 1024;
        const unsigned int end = 2048;
        const unsigned int size = end - start;

        drm_mm_init(&mm, start, size);

        if (!expect_insert_in_range_fail(&mm, 1, 0, start))
                return -EINVAL;

        if (!expect_insert_in_range_fail(&mm, size,
                                         start - size/2, start + (size+1)/2))
                return -EINVAL;

        if (!expect_insert_in_range_fail(&mm, size,
                                         end - (size+1)/2, end + size/2))
                return -EINVAL;

        if (!expect_insert_in_range_fail(&mm, 1, end, end + size))
                return -EINVAL;

        drm_mm_takedown(&mm);
        return 0;
}

static int igt_insert_range(void *ignored)
{
        const unsigned int count = min_t(unsigned int, BIT(13), max_iterations);
        unsigned int n;
        int ret;

        /* Check that requests outside the bounds of drm_mm are rejected. */
        ret = insert_outside_range();
        if (ret)

                return ret;

        for_each_prime_number_from(n, 1, 50) {
                const u64 size = BIT_ULL(n);
                const u64 max = count * size;

                ret = __igt_insert_range(count, size, 0, max);
                if (ret)
                        return ret;

                ret = __igt_insert_range(count, size, 1, max);
                if (ret)
                        return ret;

                ret = __igt_insert_range(count, size, 0, max - 1);
                if (ret)
                        return ret;

                ret = __igt_insert_range(count, size, 0, max/2);
                if (ret)
                        return ret;

                ret = __igt_insert_range(count, size, max/2, max);
                if (ret)
                        return ret;

                ret = __igt_insert_range(count, size, max/4+1, 3*max/4-1);
                if (ret)
                        return ret;

                cond_resched();
        }

        return 0;
}

static int prepare_igt_frag(struct drm_mm *mm,
                            struct drm_mm_node *nodes,
                            unsigned int num_insert,
                            const struct insert_mode *mode)
{
        unsigned int size = 4096;
        unsigned int i;

        for (i = 0; i < num_insert; i++) {
                if (!expect_insert(mm, &nodes[i], size, 0, i,
                                   mode) != 0) {
                        pr_err("%s insert failed\n", mode->name);
                        return -EINVAL;
                }
        }

        /* introduce fragmentation by freeing every other node */
        for (i = 0; i < num_insert; i++) {
                if (i % 2 == 0)
                        drm_mm_remove_node(&nodes[i]);
        }

        return 0;

}

static u64 get_insert_time(struct drm_mm *mm,
                           unsigned int num_insert,
                           struct drm_mm_node *nodes,
                           const struct insert_mode *mode)
{
        unsigned int size = 8192;
        ktime_t start;
        unsigned int i;

        start = ktime_get();
        for (i = 0; i < num_insert; i++) {
                if (!expect_insert(mm, &nodes[i], size, 0, i, mode) != 0) {
                        pr_err("%s insert failed\n", mode->name);
                        return 0;
                }
        }

        return ktime_to_ns(ktime_sub(ktime_get(), start));
}

static int igt_frag(void *ignored)
{
        struct drm_mm mm;
        const struct insert_mode *mode;
        struct drm_mm_node *nodes, *node, *next;
        unsigned int insert_size = 10000;
        unsigned int scale_factor = 4;
        int ret = -EINVAL;

        /* We need 4 * insert_size nodes to hold intermediate allocated
         * drm_mm nodes.
         * 1 times for prepare_igt_frag()
         * 1 times for get_insert_time()
         * 2 times for get_insert_time()
         */
        nodes = vzalloc(array_size(insert_size * 4, sizeof(*nodes)));
        if (!nodes)
                return -ENOMEM;

        /* For BOTTOMUP and TOPDOWN, we first fragment the
         * address space using prepare_igt_frag() and then try to verify
         * that that insertions scale quadratically from 10k to 20k insertions
         */
        drm_mm_init(&mm, 1, U64_MAX - 2);
        for (mode = insert_modes; mode->name; mode++) {
                u64 insert_time1, insert_time2;

                if (mode->mode != DRM_MM_INSERT_LOW &&
                    mode->mode != DRM_MM_INSERT_HIGH)
                        continue;

                ret = prepare_igt_frag(&mm, nodes, insert_size, mode);
                if (ret)
                        goto err;

                insert_time1 = get_insert_time(&mm, insert_size,
                                               nodes + insert_size, mode);
                if (insert_time1 == 0)
                        goto err;

                insert_time2 = get_insert_time(&mm, (insert_size * 2),
                                               nodes + insert_size * 2, mode);
                if (insert_time2 == 0)
                        goto err;

                pr_info("%s fragmented insert of %u and %u insertions took %llu and %llu nsecs\n",
                        mode->name, insert_size, insert_size * 2,
                        insert_time1, insert_time2);

                if (insert_time2 > (scale_factor * insert_time1)) {
                        pr_err("%s fragmented insert took %llu nsecs more\n",
                               mode->name,
                               insert_time2 - (scale_factor * insert_time1));
                        goto err;
                }

                drm_mm_for_each_node_safe(node, next, &mm)
                        drm_mm_remove_node(node);
        }

        ret = 0;
err:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        vfree(nodes);

        return ret;
}

static int igt_align(void *ignored)
{
        const struct insert_mode *mode;
        const unsigned int max_count = min(8192u, max_prime);
        struct drm_mm mm;
        struct drm_mm_node *nodes, *node, *next;
        unsigned int prime;
        int ret = -EINVAL;

        /* For each of the possible insertion modes, we pick a few
         * arbitrary alignments and check that the inserted node
         * meets our requirements.
         */

        nodes = vzalloc(array_size(max_count, sizeof(*nodes)));
        if (!nodes)
                goto err;

        drm_mm_init(&mm, 1, U64_MAX - 2);

        for (mode = insert_modes; mode->name; mode++) {
                unsigned int i = 0;

                for_each_prime_number_from(prime, 1, max_count) {
                        u64 size = next_prime_number(prime);

                        if (!expect_insert(&mm, &nodes[i],
                                           size, prime, i,
                                           mode)) {
                                pr_err("%s insert failed with alignment=%d",
                                       mode->name, prime);
                                goto out;
                        }

                        i++;
                }

                drm_mm_for_each_node_safe(node, next, &mm)
                        drm_mm_remove_node(node);
                DRM_MM_BUG_ON(!drm_mm_clean(&mm));

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        vfree(nodes);
err:
        return ret;
}

static int igt_align_pot(int max)
{
        struct drm_mm mm;
        struct drm_mm_node *node, *next;
        int bit;
        int ret = -EINVAL;

        /* Check that we can align to the full u64 address space */

        drm_mm_init(&mm, 1, U64_MAX - 2);

        for (bit = max - 1; bit; bit--) {
                u64 align, size;

                node = kzalloc(sizeof(*node), GFP_KERNEL);
                if (!node) {
                        ret = -ENOMEM;
                        goto out;
                }

                align = BIT_ULL(bit);
                size = BIT_ULL(bit-1) + 1;
                if (!expect_insert(&mm, node,
                                   size, align, bit,
                                   &insert_modes[0])) {
                        pr_err("insert failed with alignment=%llx [%d]",
                               align, bit);
                        goto out;
                }

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm) {
                drm_mm_remove_node(node);
                kfree(node);
        }
        drm_mm_takedown(&mm);
        return ret;
}

static int igt_align32(void *ignored)
{
        return igt_align_pot(32);
}

static int igt_align64(void *ignored)
{
        return igt_align_pot(64);
}

static void show_scan(const struct drm_mm_scan *scan)
{
        pr_info("scan: hit [%llx, %llx], size=%lld, align=%lld, color=%ld\n",
                scan->hit_start, scan->hit_end,
                scan->size, scan->alignment, scan->color);
}

static void show_holes(const struct drm_mm *mm, int count)
{
        u64 hole_start, hole_end;
        struct drm_mm_node *hole;

        drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
                struct drm_mm_node *next = list_next_entry(hole, node_list);
                const char *node1 = NULL, *node2 = NULL;

                if (drm_mm_node_allocated(hole))
                        node1 = kasprintf(GFP_KERNEL,
                                          "[%llx + %lld, color=%ld], ",
                                          hole->start, hole->size, hole->color);

                if (drm_mm_node_allocated(next))
                        node2 = kasprintf(GFP_KERNEL,
                                          ", [%llx + %lld, color=%ld]",
                                          next->start, next->size, next->color);

                pr_info("%sHole [%llx - %llx, size %lld]%s\n",
                        node1,
                        hole_start, hole_end, hole_end - hole_start,
                        node2);

                kfree(node2);
                kfree(node1);

                if (!--count)
                        break;
        }
}

struct evict_node {
        struct drm_mm_node node;
        struct list_head link;
};

static bool evict_nodes(struct drm_mm_scan *scan,
                        struct evict_node *nodes,
                        unsigned int *order,
                        unsigned int count,
                        bool use_color,
                        struct list_head *evict_list)
{
        struct evict_node *e, *en;
        unsigned int i;

        for (i = 0; i < count; i++) {
                e = &nodes[order ? order[i] : i];
                list_add(&e->link, evict_list);
                if (drm_mm_scan_add_block(scan, &e->node))
                        break;
        }
        list_for_each_entry_safe(e, en, evict_list, link) {
                if (!drm_mm_scan_remove_block(scan, &e->node))
                        list_del(&e->link);
        }
        if (list_empty(evict_list)) {
                pr_err("Failed to find eviction: size=%lld [avail=%d], align=%lld (color=%lu)\n",
                       scan->size, count, scan->alignment, scan->color);
                return false;
        }

        list_for_each_entry(e, evict_list, link)
                drm_mm_remove_node(&e->node);

        if (use_color) {
                struct drm_mm_node *node;

                while ((node = drm_mm_scan_color_evict(scan))) {
                        e = container_of(node, typeof(*e), node);
                        drm_mm_remove_node(&e->node);
                        list_add(&e->link, evict_list);
                }
        } else {
                if (drm_mm_scan_color_evict(scan)) {
                        pr_err("drm_mm_scan_color_evict unexpectedly reported overlapping nodes!\n");
                        return false;
                }
        }

        return true;
}

static bool evict_nothing(struct drm_mm *mm,
                          unsigned int total_size,
                          struct evict_node *nodes)
{
        struct drm_mm_scan scan;
        LIST_HEAD(evict_list);
        struct evict_node *e;
        struct drm_mm_node *node;
        unsigned int n;

        drm_mm_scan_init(&scan, mm, 1, 0, 0, 0);
        for (n = 0; n < total_size; n++) {
                e = &nodes[n];
                list_add(&e->link, &evict_list);
                drm_mm_scan_add_block(&scan, &e->node);
        }
        list_for_each_entry(e, &evict_list, link)
                drm_mm_scan_remove_block(&scan, &e->node);

        for (n = 0; n < total_size; n++) {
                e = &nodes[n];

                if (!drm_mm_node_allocated(&e->node)) {
                        pr_err("node[%d] no longer allocated!\n", n);
                        return false;
                }

                e->link.next = NULL;
        }

        drm_mm_for_each_node(node, mm) {
                e = container_of(node, typeof(*e), node);
                e->link.next = &e->link;
        }

        for (n = 0; n < total_size; n++) {
                e = &nodes[n];

                if (!e->link.next) {
                        pr_err("node[%d] no longer connected!\n", n);
                        return false;
                }
        }

        return assert_continuous(mm, nodes[0].node.size);
}

static bool evict_everything(struct drm_mm *mm,
                             unsigned int total_size,
                             struct evict_node *nodes)
{
        struct drm_mm_scan scan;
        LIST_HEAD(evict_list);
        struct evict_node *e;
        unsigned int n;
        int err;

        drm_mm_scan_init(&scan, mm, total_size, 0, 0, 0);
        for (n = 0; n < total_size; n++) {
                e = &nodes[n];
                list_add(&e->link, &evict_list);
                if (drm_mm_scan_add_block(&scan, &e->node))
                        break;
        }

        err = 0;
        list_for_each_entry(e, &evict_list, link) {
                if (!drm_mm_scan_remove_block(&scan, &e->node)) {
                        if (!err) {
                                pr_err("Node %lld not marked for eviction!\n",
                                       e->node.start);
                                err = -EINVAL;
                        }
                }
        }
        if (err)
                return false;

        list_for_each_entry(e, &evict_list, link)
                drm_mm_remove_node(&e->node);

        if (!assert_one_hole(mm, 0, total_size))
                return false;

        list_for_each_entry(e, &evict_list, link) {
                err = drm_mm_reserve_node(mm, &e->node);
                if (err) {
                        pr_err("Failed to reinsert node after eviction: start=%llx\n",
                               e->node.start);
                        return false;
                }
        }

        return assert_continuous(mm, nodes[0].node.size);
}

static int evict_something(struct drm_mm *mm,
                           u64 range_start, u64 range_end,
                           struct evict_node *nodes,
                           unsigned int *order,
                           unsigned int count,
                           unsigned int size,
                           unsigned int alignment,
                           const struct insert_mode *mode)
{
        struct drm_mm_scan scan;
        LIST_HEAD(evict_list);
        struct evict_node *e;
        struct drm_mm_node tmp;
        int err;

        drm_mm_scan_init_with_range(&scan, mm,
                                    size, alignment, 0,
                                    range_start, range_end,
                                    mode->mode);
        if (!evict_nodes(&scan,
                         nodes, order, count, false,
                         &evict_list))
                return -EINVAL;

        memset(&tmp, 0, sizeof(tmp));
        err = drm_mm_insert_node_generic(mm, &tmp, size, alignment, 0,
                                         DRM_MM_INSERT_EVICT);
        if (err) {
                pr_err("Failed to insert into eviction hole: size=%d, align=%d\n",
                       size, alignment);
                show_scan(&scan);
                show_holes(mm, 3);
                return err;
        }

        if (tmp.start < range_start || tmp.start + tmp.size > range_end) {
                pr_err("Inserted [address=%llu + %llu] did not fit into the request range [%llu, %llu]\n",
                       tmp.start, tmp.size, range_start, range_end);
                err = -EINVAL;
        }

        if (!assert_node(&tmp, mm, size, alignment, 0) ||
            drm_mm_hole_follows(&tmp)) {
                pr_err("Inserted did not fill the eviction hole: size=%lld [%d], align=%d [rem=%lld], start=%llx, hole-follows?=%d\n",
                       tmp.size, size,
                       alignment, misalignment(&tmp, alignment),
                       tmp.start, drm_mm_hole_follows(&tmp));
                err = -EINVAL;
        }

        drm_mm_remove_node(&tmp);
        if (err)
                return err;

        list_for_each_entry(e, &evict_list, link) {
                err = drm_mm_reserve_node(mm, &e->node);
                if (err) {
                        pr_err("Failed to reinsert node after eviction: start=%llx\n",
                               e->node.start);
                        return err;
                }
        }

        if (!assert_continuous(mm, nodes[0].node.size)) {
                pr_err("range is no longer continuous\n");
                return -EINVAL;
        }

        return 0;
}

static int igt_evict(void *ignored)
{
        DRM_RND_STATE(prng, random_seed);
        const unsigned int size = 8192;
        const struct insert_mode *mode;
        struct drm_mm mm;
        struct evict_node *nodes;
        struct drm_mm_node *node, *next;
        unsigned int *order, n;
        int ret, err;

        /* Here we populate a full drm_mm and then try and insert a new node
         * by evicting other nodes in a random order. The drm_mm_scan should
         * pick the first matching hole it finds from the random list. We
         * repeat that for different allocation strategies, alignments and
         * sizes to try and stress the hole finder.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(size, sizeof(*nodes)));
        if (!nodes)
                goto err;

        order = drm_random_order(size, &prng);
        if (!order)
                goto err_nodes;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, size);
        for (n = 0; n < size; n++) {
                err = drm_mm_insert_node(&mm, &nodes[n].node, 1);
                if (err) {
                        pr_err("insert failed, step %d\n", n);
                        ret = err;
                        goto out;
                }
        }

        /* First check that using the scanner doesn't break the mm */
        if (!evict_nothing(&mm, size, nodes)) {
                pr_err("evict_nothing() failed\n");
                goto out;
        }
        if (!evict_everything(&mm, size, nodes)) {
                pr_err("evict_everything() failed\n");
                goto out;
        }

        for (mode = evict_modes; mode->name; mode++) {
                for (n = 1; n <= size; n <<= 1) {
                        drm_random_reorder(order, size, &prng);
                        err = evict_something(&mm, 0, U64_MAX,
                                              nodes, order, size,
                                              n, 1,
                                              mode);
                        if (err) {
                                pr_err("%s evict_something(size=%u) failed\n",
                                       mode->name, n);
                                ret = err;
                                goto out;
                        }
                }

                for (n = 1; n < size; n <<= 1) {
                        drm_random_reorder(order, size, &prng);
                        err = evict_something(&mm, 0, U64_MAX,
                                              nodes, order, size,
                                              size/2, n,
                                              mode);
                        if (err) {
                                pr_err("%s evict_something(size=%u, alignment=%u) failed\n",
                                       mode->name, size/2, n);
                                ret = err;
                                goto out;
                        }
                }

                for_each_prime_number_from(n, 1, min(size, max_prime)) {
                        unsigned int nsize = (size - n + 1) / 2;

                        DRM_MM_BUG_ON(!nsize);

                        drm_random_reorder(order, size, &prng);
                        err = evict_something(&mm, 0, U64_MAX,
                                              nodes, order, size,
                                              nsize, n,
                                              mode);
                        if (err) {
                                pr_err("%s evict_something(size=%u, alignment=%u) failed\n",
                                       mode->name, nsize, n);
                                ret = err;
                                goto out;
                        }
                }

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

static int igt_evict_range(void *ignored)
{
        DRM_RND_STATE(prng, random_seed);
        const unsigned int size = 8192;
        const unsigned int range_size = size / 2;
        const unsigned int range_start = size / 4;
        const unsigned int range_end = range_start + range_size;
        const struct insert_mode *mode;
        struct drm_mm mm;
        struct evict_node *nodes;
        struct drm_mm_node *node, *next;
        unsigned int *order, n;
        int ret, err;

        /* Like igt_evict() but now we are limiting the search to a
         * small portion of the full drm_mm.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(size, sizeof(*nodes)));
        if (!nodes)
                goto err;

        order = drm_random_order(size, &prng);
        if (!order)
                goto err_nodes;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, size);
        for (n = 0; n < size; n++) {
                err = drm_mm_insert_node(&mm, &nodes[n].node, 1);
                if (err) {
                        pr_err("insert failed, step %d\n", n);
                        ret = err;
                        goto out;
                }
        }

        for (mode = evict_modes; mode->name; mode++) {
                for (n = 1; n <= range_size; n <<= 1) {
                        drm_random_reorder(order, size, &prng);
                        err = evict_something(&mm, range_start, range_end,
                                              nodes, order, size,
                                              n, 1,
                                              mode);
                        if (err) {
                                pr_err("%s evict_something(size=%u) failed with range [%u, %u]\n",
                                       mode->name, n, range_start, range_end);
                                goto out;
                        }
                }

                for (n = 1; n <= range_size; n <<= 1) {
                        drm_random_reorder(order, size, &prng);
                        err = evict_something(&mm, range_start, range_end,
                                              nodes, order, size,
                                              range_size/2, n,
                                              mode);
                        if (err) {
                                pr_err("%s evict_something(size=%u, alignment=%u) failed with range [%u, %u]\n",
                                       mode->name, range_size/2, n, range_start, range_end);
                                goto out;
                        }
                }

                for_each_prime_number_from(n, 1, min(range_size, max_prime)) {
                        unsigned int nsize = (range_size - n + 1) / 2;

                        DRM_MM_BUG_ON(!nsize);

                        drm_random_reorder(order, size, &prng);
                        err = evict_something(&mm, range_start, range_end,
                                              nodes, order, size,
                                              nsize, n,
                                              mode);
                        if (err) {
                                pr_err("%s evict_something(size=%u, alignment=%u) failed with range [%u, %u]\n",
                                       mode->name, nsize, n, range_start, range_end);
                                goto out;
                        }
                }

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

static unsigned int node_index(const struct drm_mm_node *node)
{
        return div64_u64(node->start, node->size);
}

static int igt_topdown(void *ignored)
{
        const struct insert_mode *topdown = &insert_modes[TOPDOWN];
        DRM_RND_STATE(prng, random_seed);
        const unsigned int count = 8192;
        unsigned int size;
        unsigned long *bitmap;
        struct drm_mm mm;
        struct drm_mm_node *nodes, *node, *next;
        unsigned int *order, n, m, o = 0;
        int ret;

        /* When allocating top-down, we expect to be returned a node
         * from a suitable hole at the top of the drm_mm. We check that
         * the returned node does match the highest available slot.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(count, sizeof(*nodes)));
        if (!nodes)
                goto err;

        bitmap = bitmap_zalloc(count, GFP_KERNEL);
        if (!bitmap)
                goto err_nodes;

        order = drm_random_order(count, &prng);
        if (!order)
                goto err_bitmap;

        ret = -EINVAL;
        for (size = 1; size <= 64; size <<= 1) {
                drm_mm_init(&mm, 0, size*count);
                for (n = 0; n < count; n++) {
                        if (!expect_insert(&mm, &nodes[n],
                                           size, 0, n,
                                           topdown)) {
                                pr_err("insert failed, size %u step %d\n", size, n);
                                goto out;
                        }

                        if (drm_mm_hole_follows(&nodes[n])) {
                                pr_err("hole after topdown insert %d, start=%llx\n, size=%u",
                                       n, nodes[n].start, size);
                                goto out;
                        }

                        if (!assert_one_hole(&mm, 0, size*(count - n - 1)))
                                goto out;
                }

                if (!assert_continuous(&mm, size))
                        goto out;

                drm_random_reorder(order, count, &prng);
                for_each_prime_number_from(n, 1, min(count, max_prime)) {
                        for (m = 0; m < n; m++) {
                                node = &nodes[order[(o + m) % count]];
                                drm_mm_remove_node(node);
                                __set_bit(node_index(node), bitmap);
                        }

                        for (m = 0; m < n; m++) {
                                unsigned int last;

                                node = &nodes[order[(o + m) % count]];
                                if (!expect_insert(&mm, node,
                                                   size, 0, 0,
                                                   topdown)) {
                                        pr_err("insert failed, step %d/%d\n", m, n);
                                        goto out;
                                }

                                if (drm_mm_hole_follows(node)) {
                                        pr_err("hole after topdown insert %d/%d, start=%llx\n",
                                               m, n, node->start);
                                        goto out;
                                }

                                last = find_last_bit(bitmap, count);
                                if (node_index(node) != last) {
                                        pr_err("node %d/%d, size %d, not inserted into upmost hole, expected %d, found %d\n",
                                               m, n, size, last, node_index(node));
                                        goto out;
                                }

                                __clear_bit(last, bitmap);
                        }

                        DRM_MM_BUG_ON(find_first_bit(bitmap, count) != count);

                        o += n;
                }

                drm_mm_for_each_node_safe(node, next, &mm)
                        drm_mm_remove_node(node);
                DRM_MM_BUG_ON(!drm_mm_clean(&mm));
                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_bitmap:
        bitmap_free(bitmap);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

static int igt_bottomup(void *ignored)
{
        const struct insert_mode *bottomup = &insert_modes[BOTTOMUP];
        DRM_RND_STATE(prng, random_seed);
        const unsigned int count = 8192;
        unsigned int size;
        unsigned long *bitmap;
        struct drm_mm mm;
        struct drm_mm_node *nodes, *node, *next;
        unsigned int *order, n, m, o = 0;
        int ret;

        /* Like igt_topdown, but instead of searching for the last hole,
         * we search for the first.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(count, sizeof(*nodes)));
        if (!nodes)
                goto err;

        bitmap = bitmap_zalloc(count, GFP_KERNEL);
        if (!bitmap)
                goto err_nodes;

        order = drm_random_order(count, &prng);
        if (!order)
                goto err_bitmap;

        ret = -EINVAL;
        for (size = 1; size <= 64; size <<= 1) {
                drm_mm_init(&mm, 0, size*count);
                for (n = 0; n < count; n++) {
                        if (!expect_insert(&mm, &nodes[n],
                                           size, 0, n,
                                           bottomup)) {
                                pr_err("bottomup insert failed, size %u step %d\n", size, n);
                                goto out;
                        }

                        if (!assert_one_hole(&mm, size*(n + 1), size*count))
                                goto out;
                }

                if (!assert_continuous(&mm, size))
                        goto out;

                drm_random_reorder(order, count, &prng);
                for_each_prime_number_from(n, 1, min(count, max_prime)) {
                        for (m = 0; m < n; m++) {
                                node = &nodes[order[(o + m) % count]];
                                drm_mm_remove_node(node);
                                __set_bit(node_index(node), bitmap);
                        }

                        for (m = 0; m < n; m++) {
                                unsigned int first;

                                node = &nodes[order[(o + m) % count]];
                                if (!expect_insert(&mm, node,
                                                   size, 0, 0,
                                                   bottomup)) {
                                        pr_err("insert failed, step %d/%d\n", m, n);
                                        goto out;
                                }

                                first = find_first_bit(bitmap, count);
                                if (node_index(node) != first) {
                                        pr_err("node %d/%d not inserted into bottom hole, expected %d, found %d\n",
                                               m, n, first, node_index(node));
                                        goto out;
                                }
                                __clear_bit(first, bitmap);
                        }

                        DRM_MM_BUG_ON(find_first_bit(bitmap, count) != count);

                        o += n;
                }

                drm_mm_for_each_node_safe(node, next, &mm)
                        drm_mm_remove_node(node);
                DRM_MM_BUG_ON(!drm_mm_clean(&mm));
                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_bitmap:
        bitmap_free(bitmap);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

static int __igt_once(unsigned int mode)
{
        struct drm_mm mm;
        struct drm_mm_node rsvd_lo, rsvd_hi, node;
        int err;

        drm_mm_init(&mm, 0, 7);

        memset(&rsvd_lo, 0, sizeof(rsvd_lo));
        rsvd_lo.start = 1;
        rsvd_lo.size = 1;
        err = drm_mm_reserve_node(&mm, &rsvd_lo);
        if (err) {
                pr_err("Could not reserve low node\n");
                goto err;
        }

        memset(&rsvd_hi, 0, sizeof(rsvd_hi));
        rsvd_hi.start = 5;
        rsvd_hi.size = 1;
        err = drm_mm_reserve_node(&mm, &rsvd_hi);
        if (err) {
                pr_err("Could not reserve low node\n");
                goto err_lo;
        }

        if (!drm_mm_hole_follows(&rsvd_lo) || !drm_mm_hole_follows(&rsvd_hi)) {
                pr_err("Expected a hole after lo and high nodes!\n");
                err = -EINVAL;
                goto err_hi;
        }

        memset(&node, 0, sizeof(node));
        err = drm_mm_insert_node_generic(&mm, &node, 2, 0, 0, mode);
        if (err) {
                pr_err("Could not insert the node into the available hole!\n");
                err = -EINVAL;
                goto err_hi;
        }

        drm_mm_remove_node(&node);
err_hi:
        drm_mm_remove_node(&rsvd_hi);
err_lo:
        drm_mm_remove_node(&rsvd_lo);
err:
        drm_mm_takedown(&mm);
        return err;
}

static int igt_lowest(void *ignored)
{
        return __igt_once(DRM_MM_INSERT_LOW);
}

static int igt_highest(void *ignored)
{

        return __igt_once(DRM_MM_INSERT_HIGH);
}

static void separate_adjacent_colors(const struct drm_mm_node *node,
                                     unsigned long color,
                                     u64 *start,
                                     u64 *end)
{
        if (drm_mm_node_allocated(node) && node->color != color)
                ++*start;

        node = list_next_entry(node, node_list);
        if (drm_mm_node_allocated(node) && node->color != color)
                --*end;
}

static bool colors_abutt(const struct drm_mm_node *node)
{
        if (!drm_mm_hole_follows(node) &&
            drm_mm_node_allocated(list_next_entry(node, node_list))) {
                pr_err("colors abutt; %ld [%llx + %llx] is next to %ld [%llx + %llx]!\n",
                       node->color, node->start, node->size,
                       list_next_entry(node, node_list)->color,
                       list_next_entry(node, node_list)->start,
                       list_next_entry(node, node_list)->size);
                return true;
        }

        return false;
}

static int igt_color(void *ignored)
{
        const unsigned int count = min(4096u, max_iterations);
        const struct insert_mode *mode;
        struct drm_mm mm;
        struct drm_mm_node *node, *nn;
        unsigned int n;
        int ret = -EINVAL, err;

        /* Color adjustment complicates everything. First we just check
         * that when we insert a node we apply any color_adjustment callback.
         * The callback we use should ensure that there is a gap between
         * any two nodes, and so after each insertion we check that those
         * holes are inserted and that they are preserved.
         */

        drm_mm_init(&mm, 0, U64_MAX);

        for (n = 1; n <= count; n++) {
                node = kzalloc(sizeof(*node), GFP_KERNEL);
                if (!node) {
                        ret = -ENOMEM;
                        goto out;
                }

                if (!expect_insert(&mm, node,
                                   n, 0, n,
                                   &insert_modes[0])) {
                        pr_err("insert failed, step %d\n", n);
                        kfree(node);
                        goto out;
                }
        }

        drm_mm_for_each_node_safe(node, nn, &mm) {
                if (node->color != node->size) {
                        pr_err("invalid color stored: expected %lld, found %ld\n",
                               node->size, node->color);

                        goto out;
                }

                drm_mm_remove_node(node);
                kfree(node);
        }

        /* Now, let's start experimenting with applying a color callback */
        mm.color_adjust = separate_adjacent_colors;
        for (mode = insert_modes; mode->name; mode++) {
                u64 last;

                node = kzalloc(sizeof(*node), GFP_KERNEL);
                if (!node) {
                        ret = -ENOMEM;
                        goto out;
                }

                node->size = 1 + 2*count;
                node->color = node->size;

                err = drm_mm_reserve_node(&mm, node);
                if (err) {
                        pr_err("initial reserve failed!\n");
                        ret = err;
                        goto out;
                }

                last = node->start + node->size;

                for (n = 1; n <= count; n++) {
                        int rem;

                        node = kzalloc(sizeof(*node), GFP_KERNEL);
                        if (!node) {
                                ret = -ENOMEM;
                                goto out;
                        }

                        node->start = last;
                        node->size = n + count;
                        node->color = node->size;

                        err = drm_mm_reserve_node(&mm, node);
                        if (err != -ENOSPC) {
                                pr_err("reserve %d did not report color overlap! err=%d\n",
                                       n, err);
                                goto out;
                        }

                        node->start += n + 1;
                        rem = misalignment(node, n + count);
                        node->start += n + count - rem;

                        err = drm_mm_reserve_node(&mm, node);
                        if (err) {
                                pr_err("reserve %d failed, err=%d\n", n, err);
                                ret = err;
                                goto out;
                        }

                        last = node->start + node->size;
                }

                for (n = 1; n <= count; n++) {
                        node = kzalloc(sizeof(*node), GFP_KERNEL);
                        if (!node) {
                                ret = -ENOMEM;
                                goto out;
                        }

                        if (!expect_insert(&mm, node,
                                           n, n, n,
                                           mode)) {
                                pr_err("%s insert failed, step %d\n",
                                       mode->name, n);
                                kfree(node);
                                goto out;
                        }
                }

                drm_mm_for_each_node_safe(node, nn, &mm) {
                        u64 rem;

                        if (node->color != node->size) {
                                pr_err("%s invalid color stored: expected %lld, found %ld\n",
                                       mode->name, node->size, node->color);

                                goto out;
                        }

                        if (colors_abutt(node))
                                goto out;

                        div64_u64_rem(node->start, node->size, &rem);
                        if (rem) {
                                pr_err("%s colored node misaligned, start=%llx expected alignment=%lld [rem=%lld]\n",
                                       mode->name, node->start, node->size, rem);
                                goto out;
                        }

                        drm_mm_remove_node(node);
                        kfree(node);
                }

                cond_resched();
        }

        ret = 0;
out:
        drm_mm_for_each_node_safe(node, nn, &mm) {
                drm_mm_remove_node(node);
                kfree(node);
        }
        drm_mm_takedown(&mm);
        return ret;
}

static int evict_color(struct drm_mm *mm,
                       u64 range_start, u64 range_end,
                       struct evict_node *nodes,
                       unsigned int *order,
                       unsigned int count,
                       unsigned int size,
                       unsigned int alignment,
                       unsigned long color,
                       const struct insert_mode *mode)
{
        struct drm_mm_scan scan;
        LIST_HEAD(evict_list);
        struct evict_node *e;
        struct drm_mm_node tmp;
        int err;

        drm_mm_scan_init_with_range(&scan, mm,
                                    size, alignment, color,
                                    range_start, range_end,
                                    mode->mode);
        if (!evict_nodes(&scan,
                         nodes, order, count, true,
                         &evict_list))
                return -EINVAL;

        memset(&tmp, 0, sizeof(tmp));
        err = drm_mm_insert_node_generic(mm, &tmp, size, alignment, color,
                                         DRM_MM_INSERT_EVICT);
        if (err) {
                pr_err("Failed to insert into eviction hole: size=%d, align=%d, color=%lu, err=%d\n",
                       size, alignment, color, err);
                show_scan(&scan);
                show_holes(mm, 3);
                return err;
        }

        if (tmp.start < range_start || tmp.start + tmp.size > range_end) {
                pr_err("Inserted [address=%llu + %llu] did not fit into the request range [%llu, %llu]\n",
                       tmp.start, tmp.size, range_start, range_end);
                err = -EINVAL;
        }

        if (colors_abutt(&tmp))
                err = -EINVAL;

        if (!assert_node(&tmp, mm, size, alignment, color)) {
                pr_err("Inserted did not fit the eviction hole: size=%lld [%d], align=%d [rem=%lld], start=%llx\n",
                       tmp.size, size,
                       alignment, misalignment(&tmp, alignment), tmp.start);
                err = -EINVAL;
        }

        drm_mm_remove_node(&tmp);
        if (err)
                return err;

        list_for_each_entry(e, &evict_list, link) {
                err = drm_mm_reserve_node(mm, &e->node);
                if (err) {
                        pr_err("Failed to reinsert node after eviction: start=%llx\n",
                               e->node.start);
                        return err;
                }
        }

        cond_resched();
        return 0;
}

static int igt_color_evict(void *ignored)
{
        DRM_RND_STATE(prng, random_seed);
        const unsigned int total_size = min(8192u, max_iterations);
        const struct insert_mode *mode;
        unsigned long color = 0;
        struct drm_mm mm;
        struct evict_node *nodes;
        struct drm_mm_node *node, *next;
        unsigned int *order, n;
        int ret, err;

        /* Check that the drm_mm_scan also honours color adjustment when
         * choosing its victims to create a hole. Our color_adjust does not
         * allow two nodes to be placed together without an intervening hole
         * enlarging the set of victims that must be evicted.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(total_size, sizeof(*nodes)));
        if (!nodes)
                goto err;

        order = drm_random_order(total_size, &prng);
        if (!order)
                goto err_nodes;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, 2*total_size - 1);
        mm.color_adjust = separate_adjacent_colors;
        for (n = 0; n < total_size; n++) {
                if (!expect_insert(&mm, &nodes[n].node,
                                   1, 0, color++,
                                   &insert_modes[0])) {
                        pr_err("insert failed, step %d\n", n);
                        goto out;
                }
        }

        for (mode = evict_modes; mode->name; mode++) {
                for (n = 1; n <= total_size; n <<= 1) {
                        drm_random_reorder(order, total_size, &prng);
                        err = evict_color(&mm, 0, U64_MAX,
                                          nodes, order, total_size,
                                          n, 1, color++,
                                          mode);
                        if (err) {
                                pr_err("%s evict_color(size=%u) failed\n",
                                       mode->name, n);
                                goto out;
                        }
                }

                for (n = 1; n < total_size; n <<= 1) {
                        drm_random_reorder(order, total_size, &prng);
                        err = evict_color(&mm, 0, U64_MAX,
                                          nodes, order, total_size,
                                          total_size/2, n, color++,
                                          mode);
                        if (err) {
                                pr_err("%s evict_color(size=%u, alignment=%u) failed\n",
                                       mode->name, total_size/2, n);
                                goto out;
                        }
                }

                for_each_prime_number_from(n, 1, min(total_size, max_prime)) {
                        unsigned int nsize = (total_size - n + 1) / 2;

                        DRM_MM_BUG_ON(!nsize);

                        drm_random_reorder(order, total_size, &prng);
                        err = evict_color(&mm, 0, U64_MAX,
                                          nodes, order, total_size,
                                          nsize, n, color++,
                                          mode);
                        if (err) {
                                pr_err("%s evict_color(size=%u, alignment=%u) failed\n",
                                       mode->name, nsize, n);
                                goto out;
                        }
                }

                cond_resched();
        }

        ret = 0;
out:
        if (ret)
                show_mm(&mm);
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

static int igt_color_evict_range(void *ignored)
{
        DRM_RND_STATE(prng, random_seed);
        const unsigned int total_size = 8192;
        const unsigned int range_size = total_size / 2;
        const unsigned int range_start = total_size / 4;
        const unsigned int range_end = range_start + range_size;
        const struct insert_mode *mode;
        unsigned long color = 0;
        struct drm_mm mm;
        struct evict_node *nodes;
        struct drm_mm_node *node, *next;
        unsigned int *order, n;
        int ret, err;

        /* Like igt_color_evict(), but limited to small portion of the full
         * drm_mm range.
         */

        ret = -ENOMEM;
        nodes = vzalloc(array_size(total_size, sizeof(*nodes)));
        if (!nodes)
                goto err;

        order = drm_random_order(total_size, &prng);
        if (!order)
                goto err_nodes;

        ret = -EINVAL;
        drm_mm_init(&mm, 0, 2*total_size - 1);
        mm.color_adjust = separate_adjacent_colors;
        for (n = 0; n < total_size; n++) {
                if (!expect_insert(&mm, &nodes[n].node,
                                   1, 0, color++,
                                   &insert_modes[0])) {
                        pr_err("insert failed, step %d\n", n);
                        goto out;
                }
        }

        for (mode = evict_modes; mode->name; mode++) {
                for (n = 1; n <= range_size; n <<= 1) {
                        drm_random_reorder(order, range_size, &prng);
                        err = evict_color(&mm, range_start, range_end,
                                          nodes, order, total_size,
                                          n, 1, color++,
                                          mode);
                        if (err) {
                                pr_err("%s evict_color(size=%u) failed for range [%x, %x]\n",
                                       mode->name, n, range_start, range_end);
                                goto out;
                        }
                }

                for (n = 1; n < range_size; n <<= 1) {
                        drm_random_reorder(order, total_size, &prng);
                        err = evict_color(&mm, range_start, range_end,
                                          nodes, order, total_size,
                                          range_size/2, n, color++,
                                          mode);
                        if (err) {
                                pr_err("%s evict_color(size=%u, alignment=%u) failed for range [%x, %x]\n",
                                       mode->name, total_size/2, n, range_start, range_end);
                                goto out;
                        }
                }

                for_each_prime_number_from(n, 1, min(range_size, max_prime)) {
                        unsigned int nsize = (range_size - n + 1) / 2;

                        DRM_MM_BUG_ON(!nsize);

                        drm_random_reorder(order, total_size, &prng);
                        err = evict_color(&mm, range_start, range_end,
                                          nodes, order, total_size,
                                          nsize, n, color++,
                                          mode);
                        if (err) {
                                pr_err("%s evict_color(size=%u, alignment=%u) failed for range [%x, %x]\n",
                                       mode->name, nsize, n, range_start, range_end);
                                goto out;
                        }
                }

                cond_resched();
        }

        ret = 0;
out:
        if (ret)
                show_mm(&mm);
        drm_mm_for_each_node_safe(node, next, &mm)
                drm_mm_remove_node(node);
        drm_mm_takedown(&mm);
        kfree(order);
err_nodes:
        vfree(nodes);
err:
        return ret;
}

#include "drm_selftest.c"

static int __init test_drm_mm_init(void)
{
        int err;

        while (!random_seed)
                random_seed = get_random_int();

        pr_info("Testing DRM range manager (struct drm_mm), with random_seed=0x%x max_iterations=%u max_prime=%u\n",
                random_seed, max_iterations, max_prime);
        err = run_selftests(selftests, ARRAY_SIZE(selftests), NULL);

        return err > 0 ? 0 : err;
}

static void __exit test_drm_mm_exit(void)
{
}

module_init(test_drm_mm_init);
module_exit(test_drm_mm_exit);

module_param(random_seed, uint, 0400);
module_param(max_iterations, uint, 0400);
module_param(max_prime, uint, 0400);

MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL");