// SPDX-License-Identifier: MIT
/*
 * Copyright © 2019-2021 Intel Corporation
 */

#include <drm/ttm/ttm_placement.h>
#include <linux/scatterlist.h>

#include "gem/i915_gem_region.h"
#include "intel_memory_region.h"
#include "intel_region_ttm.h"

#include "mock_region.h"

static void mock_region_put_pages(struct drm_i915_gem_object *obj,
                                  struct sg_table *pages)
{
        i915_refct_sgt_put(obj->mm.rsgt);
        obj->mm.rsgt = NULL;
        intel_region_ttm_resource_free(obj->mm.region, obj->mm.res);
}

static int mock_region_get_pages(struct drm_i915_gem_object *obj)
{
        struct sg_table *pages;
        int err;

        obj->mm.res = intel_region_ttm_resource_alloc(obj->mm.region,
                                                      obj->bo_offset,
                                                      obj->base.size,
                                                      obj->flags);
        if (IS_ERR(obj->mm.res))
                return PTR_ERR(obj->mm.res);

        obj->mm.rsgt = intel_region_ttm_resource_to_rsgt(obj->mm.region,
                                                         obj->mm.res,
                                                         obj->mm.region->min_page_size);
        if (IS_ERR(obj->mm.rsgt)) {
                err = PTR_ERR(obj->mm.rsgt);
                goto err_free_resource;
        }

        pages = &obj->mm.rsgt->table;
        __i915_gem_object_set_pages(obj, pages);

        return 0;

err_free_resource:
        intel_region_ttm_resource_free(obj->mm.region, obj->mm.res);
        return err;
}

static const struct drm_i915_gem_object_ops mock_region_obj_ops = {
        .name = "mock-region",
        .get_pages = mock_region_get_pages,
        .put_pages = mock_region_put_pages,
        .release = i915_gem_object_release_memory_region,
};

static int mock_object_init(struct intel_memory_region *mem,
                            struct drm_i915_gem_object *obj,
                            resource_size_t offset,
                            resource_size_t size,
                            resource_size_t page_size,
                            unsigned int flags)
{
        static struct lock_class_key lock_class;
        struct drm_i915_private *i915 = mem->i915;

        if (size > resource_size(&mem->region))
                return -E2BIG;

        drm_gem_private_object_init(&i915->drm, &obj->base, size);
        i915_gem_object_init(obj, &mock_region_obj_ops, &lock_class, flags);

        obj->bo_offset = offset;

        obj->read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;

        i915_gem_object_set_cache_coherency(obj, I915_CACHE_NONE);

        i915_gem_object_init_memory_region(obj, mem);

        return 0;
}

static int mock_region_fini(struct intel_memory_region *mem)
{
        struct drm_i915_private *i915 = mem->i915;
        int instance = mem->instance;
        int ret;

        ret = intel_region_ttm_fini(mem);
        ida_free(&i915->selftest.mock_region_instances, instance);

        return ret;
}

static const struct intel_memory_region_ops mock_region_ops = {
        .init = intel_region_ttm_init,
        .release = mock_region_fini,
        .init_object = mock_object_init,
};

struct intel_memory_region *
mock_region_create(struct drm_i915_private *i915,
                   resource_size_t start,
                   resource_size_t size,
                   resource_size_t min_page_size,
                   resource_size_t io_start,
                   resource_size_t io_size)
{
        int instance = ida_alloc_max(&i915->selftest.mock_region_instances,
                                     TTM_NUM_MEM_TYPES - TTM_PL_PRIV - 1,
                                     GFP_KERNEL);

        if (instance < 0)
                return ERR_PTR(instance);

        return intel_memory_region_create(i915, start, size, min_page_size,
                                          io_start, io_size,
                                          INTEL_MEMORY_MOCK, instance,
                                          &mock_region_ops);
}