// SPDX-License-Identifier: MIT
/*
 * Copyright © 2020 Intel Corporation
 */

#include "gem/i915_gem_ioctls.h"
#include "gem/i915_gem_lmem.h"
#include "gem/i915_gem_region.h"

#include "i915_drv.h"
#include "i915_trace.h"
#include "i915_user_extensions.h"

static u32 object_max_page_size(struct intel_memory_region **placements,
                                unsigned int n_placements)
{
        u32 max_page_size = 0;
        int i;

        for (i = 0; i < n_placements; i++) {
                struct intel_memory_region *mr = placements[i];

                GEM_BUG_ON(!is_power_of_2(mr->min_page_size));
                max_page_size = max_t(u32, max_page_size, mr->min_page_size);
        }

        GEM_BUG_ON(!max_page_size);
        return max_page_size;
}

static int object_set_placements(struct drm_i915_gem_object *obj,
                                 struct intel_memory_region **placements,
                                 unsigned int n_placements)
{
        struct intel_memory_region **arr;
        unsigned int i;

        GEM_BUG_ON(!n_placements);

        /*
         * For the common case of one memory region, skip storing an
         * allocated array and just point at the region directly.
         */
        if (n_placements == 1) {
                struct intel_memory_region *mr = placements[0];
                struct drm_i915_private *i915 = mr->i915;

                obj->mm.placements = &i915->mm.regions[mr->id];
                obj->mm.n_placements = 1;
        } else {
                arr = kmalloc_array(n_placements,
                                    sizeof(struct intel_memory_region *),
                                    GFP_KERNEL);
                if (!arr)
                        return -ENOMEM;

                for (i = 0; i < n_placements; i++)
                        arr[i] = placements[i];

                obj->mm.placements = arr;
                obj->mm.n_placements = n_placements;
        }

        return 0;
}

static int i915_gem_publish(struct drm_i915_gem_object *obj,
                            struct drm_file *file,
                            u64 *size_p,
                            u32 *handle_p)
{
        u64 size = obj->base.size;
        int ret;

        ret = drm_gem_handle_create(file, &obj->base, handle_p);
        /* drop reference from allocate - handle holds it now */
        i915_gem_object_put(obj);
        if (ret)
                return ret;

        *size_p = size;
        return 0;
}

/**
 * Creates a new object using the same path as DRM_I915_GEM_CREATE_EXT
 * @i915: i915 private
 * @size: size of the buffer, in bytes
 * @placements: possible placement regions, in priority order
 * @n_placements: number of possible placement regions
 *
 * This function is exposed primarily for selftests and does very little
 * error checking.  It is assumed that the set of placement regions has
 * already been verified to be valid.
 */
struct drm_i915_gem_object *
__i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
                              struct intel_memory_region **placements,
                              unsigned int n_placements)
{
        struct intel_memory_region *mr = placements[0];
        struct drm_i915_gem_object *obj;
        unsigned int flags;
        int ret;

        i915_gem_flush_free_objects(i915);

        size = round_up(size, object_max_page_size(placements, n_placements));
        if (size == 0)
                return ERR_PTR(-EINVAL);

        /* For most of the ABI (e.g. mmap) we think in system pages */
        GEM_BUG_ON(!IS_ALIGNED(size, PAGE_SIZE));

        if (i915_gem_object_size_2big(size))
                return ERR_PTR(-E2BIG);

        obj = i915_gem_object_alloc();
        if (!obj)
                return ERR_PTR(-ENOMEM);

        ret = object_set_placements(obj, placements, n_placements);
        if (ret)
                goto object_free;

        /*
         * I915_BO_ALLOC_USER will make sure the object is cleared before
         * any user access.
         */
        flags = I915_BO_ALLOC_USER;

        ret = mr->ops->init_object(mr, obj, size, 0, flags);
        if (ret)
                goto object_free;

        GEM_BUG_ON(size != obj->base.size);

        trace_i915_gem_object_create(obj);
        return obj;

object_free:
        if (obj->mm.n_placements > 1)
                kfree(obj->mm.placements);
        i915_gem_object_free(obj);
        return ERR_PTR(ret);
}

int
i915_gem_dumb_create(struct drm_file *file,
                     struct drm_device *dev,
                     struct drm_mode_create_dumb *args)
{
        struct drm_i915_gem_object *obj;
        struct intel_memory_region *mr;
        enum intel_memory_type mem_type;
        int cpp = DIV_ROUND_UP(args->bpp, 8);
        u32 format;

        switch (cpp) {
        case 1:
                format = DRM_FORMAT_C8;
                break;
        case 2:
                format = DRM_FORMAT_RGB565;
                break;
        case 4:
                format = DRM_FORMAT_XRGB8888;
                break;
        default:
                return -EINVAL;
        }

        /* have to work out size/pitch and return them */
        args->pitch = ALIGN(args->width * cpp, 64);

        /* align stride to page size so that we can remap */
        if (args->pitch > intel_plane_fb_max_stride(to_i915(dev), format,
                                                    DRM_FORMAT_MOD_LINEAR))
                args->pitch = ALIGN(args->pitch, 4096);

        if (args->pitch < args->width)
                return -EINVAL;

        args->size = mul_u32_u32(args->pitch, args->height);

        mem_type = INTEL_MEMORY_SYSTEM;
        if (HAS_LMEM(to_i915(dev)))
                mem_type = INTEL_MEMORY_LOCAL;

        mr = intel_memory_region_by_type(to_i915(dev), mem_type);

        obj = __i915_gem_object_create_user(to_i915(dev), args->size, &mr, 1);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        return i915_gem_publish(obj, file, &args->size, &args->handle);
}

/**
 * Creates a new mm object and returns a handle to it.
 * @dev: drm device pointer
 * @data: ioctl data blob
 * @file: drm file pointer
 */
int
i915_gem_create_ioctl(struct drm_device *dev, void *data,
                      struct drm_file *file)
{
        struct drm_i915_private *i915 = to_i915(dev);
        struct drm_i915_gem_create *args = data;
        struct drm_i915_gem_object *obj;
        struct intel_memory_region *mr;

        mr = intel_memory_region_by_type(i915, INTEL_MEMORY_SYSTEM);

        obj = __i915_gem_object_create_user(i915, args->size, &mr, 1);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        return i915_gem_publish(obj, file, &args->size, &args->handle);
}

struct create_ext {
        struct drm_i915_private *i915;
        struct intel_memory_region *placements[INTEL_REGION_UNKNOWN];
        unsigned int n_placements;
};

static void repr_placements(char *buf, size_t size,
                            struct intel_memory_region **placements,
                            int n_placements)
{
        int i;

        buf[0] = '\0';

        for (i = 0; i < n_placements; i++) {
                struct intel_memory_region *mr = placements[i];
                int r;

                r = snprintf(buf, size, "\n  %s -> { class: %d, inst: %d }",
                             mr->name, mr->type, mr->instance);
                if (r >= size)
                        return;

                buf += r;
                size -= r;
        }
}

static int set_placements(struct drm_i915_gem_create_ext_memory_regions *args,
                          struct create_ext *ext_data)
{
        struct drm_i915_private *i915 = ext_data->i915;
        struct drm_i915_gem_memory_class_instance __user *uregions =
                u64_to_user_ptr(args->regions);
        struct intel_memory_region *placements[INTEL_REGION_UNKNOWN];
        u32 mask;
        int i, ret = 0;

        if (args->pad) {
                drm_dbg(&i915->drm, "pad should be zero\n");
                ret = -EINVAL;
        }

        if (!args->num_regions) {
                drm_dbg(&i915->drm, "num_regions is zero\n");
                ret = -EINVAL;
        }

        BUILD_BUG_ON(ARRAY_SIZE(i915->mm.regions) != ARRAY_SIZE(placements));
        BUILD_BUG_ON(ARRAY_SIZE(ext_data->placements) != ARRAY_SIZE(placements));
        if (args->num_regions > ARRAY_SIZE(i915->mm.regions)) {
                drm_dbg(&i915->drm, "num_regions is too large\n");
                ret = -EINVAL;
        }

        if (ret)
                return ret;

        mask = 0;
        for (i = 0; i < args->num_regions; i++) {
                struct drm_i915_gem_memory_class_instance region;
                struct intel_memory_region *mr;

                if (copy_from_user(&region, uregions, sizeof(region)))
                        return -EFAULT;

                mr = intel_memory_region_lookup(i915,
                                                region.memory_class,
                                                region.memory_instance);
                if (!mr || mr->private) {
                        drm_dbg(&i915->drm, "Device is missing region { class: %d, inst: %d } at index = %d\n",
                                region.memory_class, region.memory_instance, i);
                        ret = -EINVAL;
                        goto out_dump;
                }

                if (mask & BIT(mr->id)) {
                        drm_dbg(&i915->drm, "Found duplicate placement %s -> { class: %d, inst: %d } at index = %d\n",
                                mr->name, region.memory_class,
                                region.memory_instance, i);
                        ret = -EINVAL;
                        goto out_dump;
                }

                placements[i] = mr;
                mask |= BIT(mr->id);

                ++uregions;
        }

        if (ext_data->n_placements) {
                ret = -EINVAL;
                goto out_dump;
        }

        ext_data->n_placements = args->num_regions;
        for (i = 0; i < args->num_regions; i++)
                ext_data->placements[i] = placements[i];

        return 0;

out_dump:
        if (1) {
                char buf[256];

                if (ext_data->n_placements) {
                        repr_placements(buf,
                                        sizeof(buf),
                                        ext_data->placements,
                                        ext_data->n_placements);
                        drm_dbg(&i915->drm,
                                "Placements were already set in previous EXT. Existing placements: %s\n",
                                buf);
                }

                repr_placements(buf, sizeof(buf), placements, i);
                drm_dbg(&i915->drm, "New placements(so far validated): %s\n", buf);
        }

        return ret;
}

static int ext_set_placements(struct i915_user_extension __user *base,
                              void *data)
{
        struct drm_i915_gem_create_ext_memory_regions ext;

        if (!IS_ENABLED(CONFIG_DRM_I915_UNSTABLE_FAKE_LMEM))
                return -ENODEV;

        if (copy_from_user(&ext, base, sizeof(ext)))
                return -EFAULT;

        return set_placements(&ext, data);
}

static const i915_user_extension_fn create_extensions[] = {
        [I915_GEM_CREATE_EXT_MEMORY_REGIONS] = ext_set_placements,
};

/**
 * Creates a new mm object and returns a handle to it.
 * @dev: drm device pointer
 * @data: ioctl data blob
 * @file: drm file pointer
 */
int
i915_gem_create_ext_ioctl(struct drm_device *dev, void *data,
                          struct drm_file *file)
{
        struct drm_i915_private *i915 = to_i915(dev);
        struct drm_i915_gem_create_ext *args = data;
        struct create_ext ext_data = { .i915 = i915 };
        struct drm_i915_gem_object *obj;
        int ret;

        if (args->flags)
                return -EINVAL;

        ret = i915_user_extensions(u64_to_user_ptr(args->extensions),
                                   create_extensions,
                                   ARRAY_SIZE(create_extensions),
                                   &ext_data);
        if (ret)
                return ret;

        if (!ext_data.n_placements) {
                ext_data.placements[0] =
                        intel_memory_region_by_type(i915, INTEL_MEMORY_SYSTEM);
                ext_data.n_placements = 1;
        }

        obj = __i915_gem_object_create_user(i915, args->size,
                                            ext_data.placements,
                                            ext_data.n_placements);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        return i915_gem_publish(obj, file, &args->size, &args->handle);
}