/* $Id: vbox_ttm.c 63297 2016-08-10 16:24:25Z vboxsync $ */
/** @file
 * VirtualBox Additions Linux kernel video driver
 */

/*
 * Copyright (C) 2013-2016 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 * --------------------------------------------------------------------
 *
 * This code is based on
 * ast_ttm.c
 * with the following copyright and permission notice:
 *
 * Copyright 2012 Red Hat Inc.
 *
 * 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 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.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors: Dave Airlie <airlied@redhat.com>
 */
#include "vbox_drv.h"
#include <ttm/ttm_page_alloc.h>

#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0)
# define PLACEMENT_FLAGS(placement) (placement)
#else
# define PLACEMENT_FLAGS(placement) (placement).flags
#endif

static inline struct vbox_private *
vbox_bdev(struct ttm_bo_device *bd)
{
    return container_of(bd, struct vbox_private, ttm.bdev);
}

static int
vbox_ttm_mem_global_init(struct drm_global_reference *ref)
{
    return ttm_mem_global_init(ref->object);
}

static void
vbox_ttm_mem_global_release(struct drm_global_reference *ref)
{
    ttm_mem_global_release(ref->object);
}

/**
 * Adds the vbox memory manager object/structures to the global memory manager.
 */
static int vbox_ttm_global_init(struct vbox_private *vbox)
{
    struct drm_global_reference *global_ref;
    int r;

    global_ref = &vbox->ttm.mem_global_ref;
    global_ref->global_type = DRM_GLOBAL_TTM_MEM;
    global_ref->size = sizeof(struct ttm_mem_global);
    global_ref->init = &vbox_ttm_mem_global_init;
    global_ref->release = &vbox_ttm_mem_global_release;
    r = drm_global_item_ref(global_ref);
    if (r != 0) {
        DRM_ERROR("Failed setting up TTM memory accounting "
              "subsystem.\n");
        return r;
    }

    vbox->ttm.bo_global_ref.mem_glob =
        vbox->ttm.mem_global_ref.object;
    global_ref = &vbox->ttm.bo_global_ref.ref;
    global_ref->global_type = DRM_GLOBAL_TTM_BO;
    global_ref->size = sizeof(struct ttm_bo_global);
    global_ref->init = &ttm_bo_global_init;
    global_ref->release = &ttm_bo_global_release;
    r = drm_global_item_ref(global_ref);
    if (r != 0) {
        DRM_ERROR("Failed setting up TTM BO subsystem.\n");
        drm_global_item_unref(&vbox->ttm.mem_global_ref);
        return r;
    }
    return 0;
}

/**
 * Removes the vbox memory manager object from the global memory manager.
 */
static void
vbox_ttm_global_release(struct vbox_private *vbox)
{
    if (vbox->ttm.mem_global_ref.release == NULL)
        return;

    drm_global_item_unref(&vbox->ttm.bo_global_ref.ref);
    drm_global_item_unref(&vbox->ttm.mem_global_ref);
    vbox->ttm.mem_global_ref.release = NULL;
}


static void vbox_bo_ttm_destroy(struct ttm_buffer_object *tbo)
{
    struct vbox_bo *bo;

    bo = container_of(tbo, struct vbox_bo, bo);

    drm_gem_object_release(&bo->gem);
    kfree(bo);
}

static bool vbox_ttm_bo_is_vbox_bo(struct ttm_buffer_object *bo)
{
    if (bo->destroy == &vbox_bo_ttm_destroy)
        return true;
    return false;
}

static int
vbox_bo_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
             struct ttm_mem_type_manager *man)
{
    switch (type) {
    case TTM_PL_SYSTEM:
        man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
        man->available_caching = TTM_PL_MASK_CACHING;
        man->default_caching = TTM_PL_FLAG_CACHED;
        break;
    case TTM_PL_VRAM:
        man->func = &ttm_bo_manager_func;
        man->flags = TTM_MEMTYPE_FLAG_FIXED |
            TTM_MEMTYPE_FLAG_MAPPABLE;
        man->available_caching = TTM_PL_FLAG_UNCACHED |
            TTM_PL_FLAG_WC;
        man->default_caching = TTM_PL_FLAG_WC;
        break;
    default:
        DRM_ERROR("Unsupported memory type %u\n", (unsigned)type);
        return -EINVAL;
    }
    return 0;
}

static void
vbox_bo_evict_flags(struct ttm_buffer_object *bo, struct ttm_placement *pl)
{
    struct vbox_bo *vboxbo = vbox_bo(bo);

    if (!vbox_ttm_bo_is_vbox_bo(bo))
        return;

    vbox_ttm_placement(vboxbo, TTM_PL_FLAG_SYSTEM);
    *pl = vboxbo->placement;
}

static int vbox_bo_verify_access(struct ttm_buffer_object *bo, struct file *filp)
{
    return 0;
}

static int vbox_ttm_io_mem_reserve(struct ttm_bo_device *bdev,
                  struct ttm_mem_reg *mem)
{
    struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
    struct vbox_private *vbox = vbox_bdev(bdev);

    mem->bus.addr = NULL;
    mem->bus.offset = 0;
    mem->bus.size = mem->num_pages << PAGE_SHIFT;
    mem->bus.base = 0;
    mem->bus.is_iomem = false;
    if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
        return -EINVAL;
    switch (mem->mem_type) {
    case TTM_PL_SYSTEM:
        /* system memory */
        return 0;
    case TTM_PL_VRAM:
        mem->bus.offset = mem->start << PAGE_SHIFT;
        mem->bus.base = pci_resource_start(vbox->dev->pdev, 0);
        mem->bus.is_iomem = true;
        break;
    default:
        return -EINVAL;
        break;
    }
    return 0;
}

static void vbox_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
{
}

static int vbox_bo_move(struct ttm_buffer_object *bo,
               bool evict, bool interruptible,
               bool no_wait_gpu,
               struct ttm_mem_reg *new_mem)
{
    int r;
    r = ttm_bo_move_memcpy(bo, evict, no_wait_gpu, new_mem);
    return r;
}


static void vbox_ttm_backend_destroy(struct ttm_tt *tt)
{
    ttm_tt_fini(tt);
    kfree(tt);
}

static struct ttm_backend_func vbox_tt_backend_func = {
    .destroy = &vbox_ttm_backend_destroy,
};


static struct ttm_tt *vbox_ttm_tt_create(struct ttm_bo_device *bdev,
                 unsigned long size, uint32_t page_flags,
                 struct page *dummy_read_page)
{
    struct ttm_tt *tt;

    tt = kzalloc(sizeof(struct ttm_tt), GFP_KERNEL);
    if (tt == NULL)
        return NULL;
    tt->func = &vbox_tt_backend_func;
    if (ttm_tt_init(tt, bdev, size, page_flags, dummy_read_page)) {
        kfree(tt);
        return NULL;
    }
    return tt;
}

static int vbox_ttm_tt_populate(struct ttm_tt *ttm)
{
    return ttm_pool_populate(ttm);
}

static void vbox_ttm_tt_unpopulate(struct ttm_tt *ttm)
{
    ttm_pool_unpopulate(ttm);
}

struct ttm_bo_driver vbox_bo_driver = {
    .ttm_tt_create = vbox_ttm_tt_create,
    .ttm_tt_populate = vbox_ttm_tt_populate,
    .ttm_tt_unpopulate = vbox_ttm_tt_unpopulate,
    .init_mem_type = vbox_bo_init_mem_type,
    .evict_flags = vbox_bo_evict_flags,
    .move = vbox_bo_move,
    .verify_access = vbox_bo_verify_access,
    .io_mem_reserve = &vbox_ttm_io_mem_reserve,
    .io_mem_free = &vbox_ttm_io_mem_free,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
    .lru_tail = &ttm_bo_default_lru_tail,
    .swap_lru_tail = &ttm_bo_default_swap_lru_tail,
#endif
};

int vbox_mm_init(struct vbox_private *vbox)
{
    int ret;
    struct drm_device *dev = vbox->dev;
    struct ttm_bo_device *bdev = &vbox->ttm.bdev;

    ret = vbox_ttm_global_init(vbox);
    if (ret)
        return ret;

    ret = ttm_bo_device_init(&vbox->ttm.bdev,
                 vbox->ttm.bo_global_ref.ref.object,
                 &vbox_bo_driver,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 15, 0)
                 dev->anon_inode->i_mapping,
#endif
                 DRM_FILE_PAGE_OFFSET,
                 true);
    if (ret) {
        DRM_ERROR("Error initialising bo driver; %d\n", ret);
        return ret;
    }

    ret = ttm_bo_init_mm(bdev, TTM_PL_VRAM,
                 vbox->available_vram_size >> PAGE_SHIFT);
    if (ret) {
        DRM_ERROR("Failed ttm VRAM init: %d\n", ret);
        return ret;
    }

#ifdef DRM_MTRR_WC
    vbox->fb_mtrr = drm_mtrr_add(pci_resource_start(dev->pdev, 0),
                    pci_resource_len(dev->pdev, 0),
                    DRM_MTRR_WC);
#else
    vbox->fb_mtrr = arch_phys_wc_add(pci_resource_start(dev->pdev, 0),
                    pci_resource_len(dev->pdev, 0));
#endif

    vbox->ttm.mm_initialised = true;
    return 0;
}

void vbox_mm_fini(struct vbox_private *vbox)
{
#ifdef DRM_MTRR_WC
    struct drm_device *dev = vbox->dev;
#endif
    if (!vbox->ttm.mm_initialised)
        return;
    ttm_bo_device_release(&vbox->ttm.bdev);

    vbox_ttm_global_release(vbox);

#ifdef DRM_MTRR_WC
    drm_mtrr_del(vbox->fb_mtrr,
             pci_resource_start(dev->pdev, 0),
             pci_resource_len(dev->pdev, 0), DRM_MTRR_WC);
#else
    arch_phys_wc_del(vbox->fb_mtrr);
#endif
}

void vbox_ttm_placement(struct vbox_bo *bo, int domain)
{
    u32 c = 0;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0)
    bo->placement.fpfn = 0;
    bo->placement.lpfn = 0;
#else
    unsigned i;
#endif

    bo->placement.placement = bo->placements;
    bo->placement.busy_placement = bo->placements;
    if (domain & TTM_PL_FLAG_VRAM)
        PLACEMENT_FLAGS(bo->placements[c++]) = TTM_PL_FLAG_WC | TTM_PL_FLAG_UNCACHED | TTM_PL_FLAG_VRAM;
    if (domain & TTM_PL_FLAG_SYSTEM)
        PLACEMENT_FLAGS(bo->placements[c++]) = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM;
    if (!c)
        PLACEMENT_FLAGS(bo->placements[c++]) = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM;
    bo->placement.num_placement = c;
    bo->placement.num_busy_placement = c;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 18, 0)
    for (i = 0; i < c; ++i) {
        bo->placements[i].fpfn = 0;
        bo->placements[i].lpfn = 0;
    }
#endif
}

int vbox_bo_create(struct drm_device *dev, int size, int align,
          uint32_t flags, struct vbox_bo **pvboxbo)
{
    struct vbox_private *vbox = dev->dev_private;
    struct vbox_bo *vboxbo;
    size_t acc_size;
    int ret;

    vboxbo = kzalloc(sizeof(struct vbox_bo), GFP_KERNEL);
    if (!vboxbo)
        return -ENOMEM;

    ret = drm_gem_object_init(dev, &vboxbo->gem, size);
    if (ret) {
        kfree(vboxbo);
        return ret;
    }

    vboxbo->bo.bdev = &vbox->ttm.bdev;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 15, 0)
    vboxbo->bo.bdev->dev_mapping = dev->dev_mapping;
#endif

    vbox_ttm_placement(vboxbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);

    acc_size = ttm_bo_dma_acc_size(&vbox->ttm.bdev, size,
                       sizeof(struct vbox_bo));

    ret = ttm_bo_init(&vbox->ttm.bdev, &vboxbo->bo, size,
              ttm_bo_type_device, &vboxbo->placement,
              align >> PAGE_SHIFT, false, NULL, acc_size,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 18, 0)
              NULL,
#endif
              NULL, vbox_bo_ttm_destroy);
    if (ret)
        return ret;

    *pvboxbo = vboxbo;
    return 0;
}

static inline u64 vbox_bo_gpu_offset(struct vbox_bo *bo)
{
    return bo->bo.offset;
}

int vbox_bo_pin(struct vbox_bo *bo, u32 pl_flag, u64 *gpu_addr)
{
    int i, ret;

    if (bo->pin_count) {
        bo->pin_count++;
        if (gpu_addr)
            *gpu_addr = vbox_bo_gpu_offset(bo);
        return 0;
    }

    vbox_ttm_placement(bo, pl_flag);
    for (i = 0; i < bo->placement.num_placement; i++)
        PLACEMENT_FLAGS(bo->placements[i]) |= TTM_PL_FLAG_NO_EVICT;
    ret = ttm_bo_validate(&bo->bo, &bo->placement, false, false);
    if (ret)
        return ret;

    bo->pin_count = 1;
    if (gpu_addr)
        *gpu_addr = vbox_bo_gpu_offset(bo);
    return 0;
}

int vbox_bo_unpin(struct vbox_bo *bo)
{
    int i, ret;
    if (!bo->pin_count) {
        DRM_ERROR("unpin bad %p\n", bo);
        return 0;
    }
    bo->pin_count--;
    if (bo->pin_count)
        return 0;

    for (i = 0; i < bo->placement.num_placement ; i++)
        PLACEMENT_FLAGS(bo->placements[i]) &= ~TTM_PL_FLAG_NO_EVICT;
    ret = ttm_bo_validate(&bo->bo, &bo->placement, false, false);
    if (ret)
        return ret;

    return 0;
}

/* Move a vbox-owned buffer object to system memory if no one else has it
 * pinned.  The caller must have pinned it previously, and this call will
 * release the caller's pin. */
int vbox_bo_push_sysram(struct vbox_bo *bo)
{
    int i, ret;
    if (!bo->pin_count) {
        DRM_ERROR("unpin bad %p\n", bo);
        return 0;
    }
    bo->pin_count--;
    if (bo->pin_count)
        return 0;

    if (bo->kmap.virtual)
        ttm_bo_kunmap(&bo->kmap);

    vbox_ttm_placement(bo, TTM_PL_FLAG_SYSTEM);
    for (i = 0; i < bo->placement.num_placement ; i++)
        PLACEMENT_FLAGS(bo->placements[i]) |= TTM_PL_FLAG_NO_EVICT;

    ret = ttm_bo_validate(&bo->bo, &bo->placement, false, false);
    if (ret) {
        DRM_ERROR("pushing to VRAM failed\n");
        return ret;
    }
    return 0;
}

int vbox_mmap(struct file *filp, struct vm_area_struct *vma)
{
    struct drm_file *file_priv;
    struct vbox_private *vbox;

    if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET))
        return -EINVAL;

    file_priv = filp->private_data;
    vbox = file_priv->minor->dev->dev_private;
    return ttm_bo_mmap(filp, vma, &vbox->ttm.bdev);
}