ttm_agp_backend.c

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/**************************************************************************
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
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 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
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 *
 * The above copyright notice and this permission notice (including the
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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/*
 * 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>
#ifdef TTM_HAS_AGP
#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;
    struct agp_bridge_data *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 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_allocate_memory(agp_be->bridge, ttm->num_pages, AGP_USER_MEMORY);
    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 = ttm->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_bo_device *bdev,
                 struct agp_bridge_data *bridge,
                 unsigned long size, uint32_t page_flags,
                 struct page *dummy_read_page)
{
    struct ttm_agp_backend *agp_be;

    agp_be = kmalloc(sizeof(*agp_be), GFP_KERNEL);
    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, bdev, size, page_flags, dummy_read_page)) {
        return NULL;
    }

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

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

    return ttm_pool_populate(ttm);
}
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);

#endif