/*-
 * Copyright (c) 2009 Robert C. Noland III <rnoland@FreeBSD.org>
 * 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, sublicense,
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * PRECISION INSIGHT 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.
 *
 * $FreeBSD: src/sys/dev/drm2/drm_scatter.c,v 1.1 2012/05/22 11:07:44 kib Exp $
 */

/** @file drm_scatter.c
 * Allocation of memory for scatter-gather mappings by the graphics chip.
 * The memory allocated here is then made into an aperture in the card
 * by mapping the pages into the GART.
 */

#include <drm/drmP.h>
#include "drm_legacy.h"

#include <vm/vm_kern.h>

static void drm_sg_cleanup(struct drm_sg_mem * entry)
{
        if (entry == NULL)
                return;

        if (entry->vaddr != 0)
                kmem_free(kernel_map, entry->vaddr, IDX_TO_OFF(entry->pages));

        kfree(entry->busaddr);
        kfree(entry);
}

void drm_legacy_sg_cleanup(struct drm_device *dev)
{
        if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
            drm_core_check_feature(dev, DRIVER_LEGACY)) {
                drm_sg_cleanup(dev->sg);
                dev->sg = NULL;
        }
}

int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
                        struct drm_file *file_priv)
{
        struct drm_scatter_gather *request = data;
        struct drm_sg_mem *entry;
        vm_size_t size;
        vm_pindex_t pindex;

        DRM_DEBUG("\n");

        if (!drm_core_check_feature(dev, DRIVER_LEGACY))
                return -EOPNOTSUPP;

        if (!drm_core_check_feature(dev, DRIVER_SG))
                return -EOPNOTSUPP;

        if (dev->sg)
                return -EINVAL;

        DRM_DEBUG("request size=%ld\n", request->size);

        entry = kmalloc(sizeof(*entry), M_DRM, M_WAITOK | M_ZERO);

        size = round_page(request->size);
        entry->pages = OFF_TO_IDX(size);
        entry->busaddr = kmalloc(entry->pages * sizeof(*entry->busaddr),
            M_DRM, M_WAITOK | M_ZERO);

        entry->vaddr = kmem_alloc_attr(kernel_map, size,
                                       VM_SUBSYS_DRM_SCAT, M_WAITOK | M_ZERO,
                                       0, BUS_SPACE_MAXADDR_32BIT,
                                       VM_MEMATTR_WRITE_COMBINING);
        if (entry->vaddr == 0) {
                drm_sg_cleanup(entry);
                return (-ENOMEM);
        }

        for(pindex = 0; pindex < entry->pages; pindex++) {
                entry->busaddr[pindex] =
                    vtophys(entry->vaddr + IDX_TO_OFF(pindex));
        }

        DRM_LOCK(dev);
        if (dev->sg) {
                DRM_UNLOCK(dev);
                drm_sg_cleanup(entry);
                return (-EINVAL);
        }
        dev->sg = entry;
        DRM_UNLOCK(dev);

        request->handle = entry->vaddr;

        DRM_DEBUG("allocated %ju pages @ 0x%08jx, contents=%08lx\n",
            entry->pages, (uintmax_t)entry->vaddr,
            *(unsigned long *)entry->vaddr);

        return (0);
}

int drm_legacy_sg_free(struct drm_device *dev, void *data,
                       struct drm_file *file_priv)
{
        struct drm_scatter_gather *request = data;
        struct drm_sg_mem *entry;

        if (!drm_core_check_feature(dev, DRIVER_LEGACY))
                return -EOPNOTSUPP;

        if (!drm_core_check_feature(dev, DRIVER_SG))
                return -EOPNOTSUPP;

        entry = dev->sg;
        dev->sg = NULL;

        if (!entry || entry->vaddr != request->handle)
                return -EINVAL;

        DRM_DEBUG("free 0x%jx\n", (uintmax_t)entry->vaddr);

        drm_sg_cleanup(entry);

        return 0;
}