/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 *          Keith Packard.
 */

#define pr_fmt(fmt) "[TTM] " fmt

#include <drm/ttm/ttm_module.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_page_alloc.h>
#include <drm/ttm/ttm_placement.h>
#include <linux/agp_backend.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <asm/agp.h>

struct ttm_agp_backend {
        struct ttm_tt ttm;
        struct agp_memory *mem;
        device_t bridge;
};

static int ttm_agp_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
{
        struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);
        struct page *dummy_read_page = ttm->bdev->glob->dummy_read_page;
        struct drm_mm_node *node = bo_mem->mm_node;
        struct agp_memory *mem;
        int ret, cached = (bo_mem->placement & TTM_PL_FLAG_CACHED);
        unsigned i;

        mem = agp_alloc_memory(agp_be->bridge, AGP_USER_MEMORY, ttm->num_pages);
        if (unlikely(mem == NULL))
                return -ENOMEM;

        mem->page_count = 0;
        for (i = 0; i < ttm->num_pages; i++) {
                struct page *page = ttm->pages[i];

                if (!page)
                        page = dummy_read_page;

                mem->pages[mem->page_count++] = page;
        }
        agp_be->mem = mem;

        mem->is_flushed = 1;
        mem->type = (cached) ? AGP_USER_CACHED_MEMORY : AGP_USER_MEMORY;

        ret = agp_bind_memory(mem, node->start);
        if (ret)
                pr_err("AGP Bind memory failed\n");

        return ret;
}

static int ttm_agp_unbind(struct ttm_tt *ttm)
{
        struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);

        if (agp_be->mem) {
                if (agp_be->mem->is_bound)
                        return agp_unbind_memory(agp_be->mem);
                agp_free_memory(agp_be->mem);
                agp_be->mem = NULL;
        }
        return 0;
}

static void ttm_agp_destroy(struct ttm_tt *ttm)
{
        struct ttm_agp_backend *agp_be = container_of(ttm, struct ttm_agp_backend, ttm);

        if (agp_be->mem)
                ttm_agp_unbind(ttm);
        ttm_tt_fini(ttm);
        kfree(agp_be);
}

static struct ttm_backend_func ttm_agp_func = {
        .bind = ttm_agp_bind,
        .unbind = ttm_agp_unbind,
        .destroy = ttm_agp_destroy,
};

struct ttm_tt *ttm_agp_tt_create(struct ttm_buffer_object *bo,
                                 device_t bridge,
                                 uint32_t page_flags)
{
        struct ttm_agp_backend *agp_be;

        agp_be = kmalloc(sizeof(*agp_be), M_DRM, M_WAITOK);
        if (!agp_be)
                return NULL;

        agp_be->mem = NULL;
        agp_be->bridge = bridge;
        agp_be->ttm.func = &ttm_agp_func;

        if (ttm_tt_init(&agp_be->ttm, bo, page_flags)) {
                kfree(agp_be);
                return NULL;
        }

        return &agp_be->ttm;
}
EXPORT_SYMBOL(ttm_agp_tt_create);

int ttm_agp_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
{
        if (ttm->state != tt_unpopulated)
                return 0;

        return ttm_pool_populate(ttm, ctx);
}
EXPORT_SYMBOL(ttm_agp_tt_populate);

void ttm_agp_tt_unpopulate(struct ttm_tt *ttm)
{
        ttm_pool_unpopulate(ttm);
}
EXPORT_SYMBOL(ttm_agp_tt_unpopulate);