/*-
 * 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.
 */

#include <sys/cdefs.h>
/** @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 <dev/drm2/drmP.h>

#define DEBUG_SCATTER 0

static inline void *drm_vmalloc_dma(vm_size_t size)
{
        return kmem_alloc_attr(size, M_NOWAIT | M_ZERO, 0,
            BUS_SPACE_MAXADDR_32BIT, VM_MEMATTR_WRITE_COMBINING);
}

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

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

        free(entry->busaddr, DRM_MEM_SGLISTS);
        free(entry, DRM_MEM_DRIVER);
}

int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request)
{
        struct drm_sg_mem *entry;
        vm_size_t size;
        vm_pindex_t pindex;

        DRM_DEBUG("\n");

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

        if (dev->sg)
                return -EINVAL;

        entry = malloc(sizeof(*entry), DRM_MEM_DRIVER, M_NOWAIT | M_ZERO);
        if (!entry)
                return -ENOMEM;

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

        size = round_page(request->size);
        entry->pages = atop(size);
        entry->busaddr = malloc(entry->pages * sizeof(*entry->busaddr),
            DRM_MEM_SGLISTS, M_NOWAIT | M_ZERO);
        if (!entry->busaddr) {
                free(entry, DRM_MEM_DRIVER);
                return -ENOMEM;
        }

        entry->vaddr = drm_vmalloc_dma(size);
        if (entry->vaddr == NULL) {
                free(entry->busaddr, DRM_MEM_DRIVER);
                free(entry, DRM_MEM_DRIVER);
                return -ENOMEM;
        }

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

        request->handle = (uintptr_t)entry->vaddr;

        dev->sg = entry;

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

        return 0;
}

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

        return drm_sg_alloc(dev, request);

}

int drm_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_SG))
                return -EINVAL;

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

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

        DRM_DEBUG("free %p\n", entry->vaddr);

        drm_sg_cleanup(entry);

        return 0;
}