/* $Id: vbox_main.c 65381 2017-01-20 09:23:53Z 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_main.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 <VBoxVideoGuest.h>
#include <VBoxVideoVBE.h>

#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>

static void vbox_user_framebuffer_destroy(struct drm_framebuffer *fb)
{
    struct vbox_framebuffer *vbox_fb = to_vbox_framebuffer(fb);
    if (vbox_fb->obj)
        drm_gem_object_unreference_unlocked(vbox_fb->obj);

    drm_framebuffer_cleanup(fb);
    kfree(fb);
}

void vbox_enable_accel(struct vbox_private *vbox)
{
    unsigned i;
    struct VBVABUFFER *vbva;
    uint32_t vram_map_offset = vbox->available_vram_size - vbox->vram_map_start;

    if (vbox->vbva_info == NULL) {  /* Should never happen... */
        printk(KERN_ERR "vboxvideo: failed to set up VBVA.\n");
        return;
    }
    for (i = 0; i < vbox->num_crtcs; ++i) {
        if (vbox->vbva_info[i].pVBVA == NULL) {
            vbva = (struct VBVABUFFER *) (  ((uint8_t *)vbox->mapped_vram)
                                           + vram_map_offset
                                           + i * VBVA_MIN_BUFFER_SIZE);
            if (!VBoxVBVAEnable(&vbox->vbva_info[i], &vbox->submit_info, vbva, i)) {
                /* very old host or driver error. */
                printk(KERN_ERR "vboxvideo: VBoxVBVAEnable failed - heap allocation error.\n");
                return;
            }
        }
    }
}

void vbox_disable_accel(struct vbox_private *vbox)
{
    unsigned i;

    for (i = 0; i < vbox->num_crtcs; ++i)
        VBoxVBVADisable(&vbox->vbva_info[i], &vbox->submit_info, i);
}

void vbox_report_caps(struct vbox_private *vbox)
{
    uint32_t caps =    VBVACAPS_DISABLE_CURSOR_INTEGRATION
                     | VBVACAPS_IRQ
                     | VBVACAPS_USE_VBVA_ONLY;
    if (vbox->initial_mode_queried)
        caps |= VBVACAPS_VIDEO_MODE_HINTS;
    VBoxHGSMISendCapsInfo(&vbox->submit_info, caps);
}

/** Send information about dirty rectangles to VBVA.  If necessary we enable
 * VBVA first, as this is normally disabled after a change of master in case
 * the new master does not send dirty rectangle information (is this even
 * allowed?) */
void vbox_framebuffer_dirty_rectangles(struct drm_framebuffer *fb,
                                       struct drm_clip_rect *rects,
                                       unsigned num_rects)
{
    struct vbox_private *vbox = fb->dev->dev_private;
    struct drm_crtc *crtc;
    unsigned i;

    mutex_lock(&vbox->hw_mutex);
    list_for_each_entry(crtc, &fb->dev->mode_config.crtc_list, head) {
        if (CRTC_FB(crtc) == fb) {
            vbox_enable_accel(vbox);
            for (i = 0; i < num_rects; ++i)
            {
                unsigned crtc_id = to_vbox_crtc(crtc)->crtc_id;
                VBVACMDHDR cmd_hdr;

                if (   rects[i].x1 >   crtc->x
                                      + crtc->hwmode.hdisplay
                    || rects[i].y1 >   crtc->y
                                      + crtc->hwmode.vdisplay
                    || rects[i].x2 < crtc->x
                    || rects[i].y2 < crtc->y)
                    continue;
                cmd_hdr.x = (int16_t)rects[i].x1;
                cmd_hdr.y = (int16_t)rects[i].y1;
                cmd_hdr.w = (uint16_t)rects[i].x2 - rects[i].x1;
                cmd_hdr.h = (uint16_t)rects[i].y2 - rects[i].y1;
                if (VBoxVBVABufferBeginUpdate(&vbox->vbva_info[crtc_id],
                                              &vbox->submit_info))
                {
                    VBoxVBVAWrite(&vbox->vbva_info[crtc_id], &vbox->submit_info, &cmd_hdr,
                                  sizeof(cmd_hdr));
                    VBoxVBVABufferEndUpdate(&vbox->vbva_info[crtc_id]);
                }
            }
        }
    }
    mutex_unlock(&vbox->hw_mutex);
}

static int vbox_user_framebuffer_dirty(struct drm_framebuffer *fb,
                                       struct drm_file *file_priv,
                                       unsigned flags, unsigned color,
                                       struct drm_clip_rect *rects,
                                       unsigned num_rects)
{
    vbox_framebuffer_dirty_rectangles(fb, rects, num_rects);
    return 0;
}

static const struct drm_framebuffer_funcs vbox_fb_funcs = {
    .destroy = vbox_user_framebuffer_destroy,
    .dirty = vbox_user_framebuffer_dirty,
};


int vbox_framebuffer_init(struct drm_device *dev,
             struct vbox_framebuffer *vbox_fb,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)
             const
#endif
             struct DRM_MODE_FB_CMD *mode_cmd,
             struct drm_gem_object *obj)
{
    int ret;

    drm_helper_mode_fill_fb_struct(&vbox_fb->base, mode_cmd);
    vbox_fb->obj = obj;
    ret = drm_framebuffer_init(dev, &vbox_fb->base, &vbox_fb_funcs);
    if (ret) {
        DRM_ERROR("framebuffer init failed %d\n", ret);
        return ret;
    }
    return 0;
}

static struct drm_framebuffer *
vbox_user_framebuffer_create(struct drm_device *dev,
           struct drm_file *filp,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)
           const
#endif
           struct drm_mode_fb_cmd2 *mode_cmd)
{
    struct drm_gem_object *obj;
    struct vbox_framebuffer *vbox_fb;
    int ret;

#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
    obj = drm_gem_object_lookup(filp, mode_cmd->handles[0]);
#else
    obj = drm_gem_object_lookup(dev, filp, mode_cmd->handles[0]);
#endif
    if (obj == NULL)
        return ERR_PTR(-ENOENT);

    vbox_fb = kzalloc(sizeof(*vbox_fb), GFP_KERNEL);
    if (!vbox_fb) {
        drm_gem_object_unreference_unlocked(obj);
        return ERR_PTR(-ENOMEM);
    }

    ret = vbox_framebuffer_init(dev, vbox_fb, mode_cmd, obj);
    if (ret) {
        drm_gem_object_unreference_unlocked(obj);
        kfree(vbox_fb);
        return ERR_PTR(ret);
    }
    return &vbox_fb->base;
}

static const struct drm_mode_config_funcs vbox_mode_funcs = {
    .fb_create = vbox_user_framebuffer_create,
};

static void vbox_accel_fini(struct vbox_private *vbox)
{
    if (vbox->vbva_info)
    {
        vbox_disable_accel(vbox);
        kfree(vbox->vbva_info);
        vbox->vbva_info = NULL;
    }
}

static int vbox_accel_init(struct vbox_private *vbox)
{
    unsigned i;
    if (!vbox->vbva_info)
    {
        vbox->vbva_info = kzalloc(  sizeof(struct VBVABUFFERCONTEXT)
                                  * vbox->num_crtcs,
                                  GFP_KERNEL);
        if (!vbox->vbva_info)
            return -ENOMEM;
    }
    /* Take a command buffer for each screen from the end of usable VRAM. */
    vbox->available_vram_size -= vbox->num_crtcs * VBVA_MIN_BUFFER_SIZE;
    for (i = 0; i < vbox->num_crtcs; ++i)
        VBoxVBVASetupBufferContext(&vbox->vbva_info[i],
                                   vbox->available_vram_size + i * VBVA_MIN_BUFFER_SIZE,
                                   VBVA_MIN_BUFFER_SIZE);
    return 0;
}

/** Allocation function for the HGSMI heap and data. */
static DECLCALLBACK(void *) alloc_hgsmi_environ(void *environ, HGSMISIZE size)
{
    NOREF(environ);
    return kmalloc(size, GFP_KERNEL);
}


/** Free function for the HGSMI heap and data. */
static DECLCALLBACK(void) free_hgsmi_environ(void *environ, void *ptr)
{
    NOREF(environ);
    kfree(ptr);
}


/** Pointers to the HGSMI heap and data manipulation functions. */
static HGSMIENV hgsmi_environ =
{
    NULL,
    alloc_hgsmi_environ,
    free_hgsmi_environ
};


/** Do we support the 4.3 plus mode hint reporting interface? */
static bool have_hgsmi_mode_hints(struct vbox_private *vbox)
{
    uint32_t have_hints, have_cursor;

    return    RT_SUCCESS(VBoxQueryConfHGSMI(&vbox->submit_info, VBOX_VBVA_CONF32_MODE_HINT_REPORTING, &have_hints))
           && RT_SUCCESS(VBoxQueryConfHGSMI(&vbox->submit_info, VBOX_VBVA_CONF32_GUEST_CURSOR_REPORTING, &have_cursor))
           && have_hints == VINF_SUCCESS
           && have_cursor == VINF_SUCCESS;
}

#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
# define pci_iomap_range(dev, bar, offset, maxlen) \
    ioremap(pci_resource_start(dev, bar) + offset, maxlen)
#endif

/** Set up our heaps and data exchange buffers in VRAM before handing the rest
 *  to the memory manager. */
static int vbox_hw_init(struct vbox_private *vbox)
{
    uint32_t base_offset, map_start, guest_heap_offset, guest_heap_size, host_flags_offset;
    void *guest_heap;

    vbox->full_vram_size = VBoxVideoGetVRAMSize();
    vbox->any_pitch = VBoxVideoAnyWidthAllowed();
    DRM_INFO("VRAM %08x\n", vbox->full_vram_size);
    VBoxHGSMIGetBaseMappingInfo(vbox->full_vram_size, &base_offset, NULL,
                                &guest_heap_offset, &guest_heap_size, &host_flags_offset);
    map_start = (uint32_t)max((int)base_offset
                              - VBOX_MAX_SCREENS * VBVA_MIN_BUFFER_SIZE, 0);
    vbox->mapped_vram = pci_iomap_range(vbox->dev->pdev, 0, map_start,
                                        vbox->full_vram_size - map_start);
    if (!vbox->mapped_vram)
        return -ENOMEM;
    vbox->vram_map_start = map_start;
    guest_heap = ((uint8_t *)vbox->mapped_vram) + base_offset - map_start
                   + guest_heap_offset;
    vbox->host_flags_offset = base_offset - map_start + host_flags_offset;
    if (RT_FAILURE(VBoxHGSMISetupGuestContext(&vbox->submit_info, guest_heap,
                                              guest_heap_size,
                                              base_offset + guest_heap_offset,
                                              &hgsmi_environ)))
        return -ENOMEM;
    /* Reduce available VRAM size to reflect the guest heap. */
    vbox->available_vram_size = base_offset;
    /* Linux drm represents monitors as a 32-bit array. */
    vbox->num_crtcs = min(VBoxHGSMIGetMonitorCount(&vbox->submit_info),
                          (uint32_t)VBOX_MAX_SCREENS);
    if (!have_hgsmi_mode_hints(vbox))
        return -ENOTSUPP;
    vbox->last_mode_hints = kzalloc(sizeof(VBVAMODEHINT) * vbox->num_crtcs, GFP_KERNEL);
    if (!vbox->last_mode_hints)
        return -ENOMEM;
    return vbox_accel_init(vbox);
}

static void vbox_hw_fini(struct vbox_private *vbox)
{
    vbox_accel_fini(vbox);
    if (vbox->last_mode_hints)
        kfree(vbox->last_mode_hints);
    vbox->last_mode_hints = NULL;
}

int vbox_driver_load(struct drm_device *dev, unsigned long flags)
{
    struct vbox_private *vbox;
    int ret = 0;

    if (!VBoxHGSMIIsSupported())
        return -ENODEV;
    vbox = kzalloc(sizeof(struct vbox_private), GFP_KERNEL);
    if (!vbox)
        return -ENOMEM;

    dev->dev_private = vbox;
    vbox->dev = dev;

    mutex_init(&vbox->hw_mutex);

    ret = vbox_hw_init(vbox);
    if (ret)
        goto out_free;

    ret = vbox_mm_init(vbox);
    if (ret)
        goto out_free;

    drm_mode_config_init(dev);

    dev->mode_config.funcs = (void *)&vbox_mode_funcs;
    dev->mode_config.min_width = 64;
    dev->mode_config.min_height = 64;
    dev->mode_config.preferred_depth = 24;
    dev->mode_config.max_width = VBE_DISPI_MAX_XRES;
    dev->mode_config.max_height = VBE_DISPI_MAX_YRES;

    ret = vbox_mode_init(dev);
    if (ret)
        goto out_free;

    ret = vbox_irq_init(vbox);
    if (ret)
        goto out_free;

    ret = vbox_fbdev_init(dev);
    if (ret)
        goto out_free;
    return 0;
out_free:
    vbox_driver_unload(dev);
    return ret;
}

int vbox_driver_unload(struct drm_device *dev)
{
    struct vbox_private *vbox = dev->dev_private;

    vbox_fbdev_fini(dev);
    vbox_irq_fini(vbox);
    vbox_mode_fini(dev);
    if (dev->mode_config.funcs)
        drm_mode_config_cleanup(dev);

    vbox_hw_fini(vbox);
    vbox_mm_fini(vbox);
    if (vbox->mapped_vram)
        pci_iounmap(dev->pdev, vbox->mapped_vram);
    kfree(vbox);
    dev->dev_private = NULL;
    return 0;
}

/** @note this is described in the DRM framework documentation.  AST does not
 *        have it, but we get an oops on driver unload if it is not present. */
void vbox_driver_lastclose(struct drm_device *dev)
{
    struct vbox_private *vbox = dev->dev_private;

#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 16, 0)
    if (vbox->fbdev)
        drm_fb_helper_restore_fbdev_mode_unlocked(&vbox->fbdev->helper);
#else
    drm_modeset_lock_all(dev);
    if (vbox->fbdev)
        drm_fb_helper_restore_fbdev_mode(&vbox->fbdev->helper);
    drm_modeset_unlock_all(dev);
#endif
}

int vbox_gem_create(struct drm_device *dev,
           u32 size, bool iskernel,
           struct drm_gem_object **obj)
{
    struct vbox_bo *vboxbo;
    int ret;

    *obj = NULL;

    size = roundup(size, PAGE_SIZE);
    if (size == 0)
        return -EINVAL;

    ret = vbox_bo_create(dev, size, 0, 0, &vboxbo);
    if (ret) {
        if (ret != -ERESTARTSYS)
            DRM_ERROR("failed to allocate GEM object\n");
        return ret;
    }
    *obj = &vboxbo->gem;
    return 0;
}

int vbox_dumb_create(struct drm_file *file,
            struct drm_device *dev,
            struct drm_mode_create_dumb *args)
{
    int ret;
    struct drm_gem_object *gobj;
    u32 handle;

    args->pitch = args->width * ((args->bpp + 7) / 8);
    args->size = args->pitch * args->height;

    ret = vbox_gem_create(dev, args->size, false,
                 &gobj);
    if (ret)
        return ret;

    ret = drm_gem_handle_create(file, gobj, &handle);
    drm_gem_object_unreference_unlocked(gobj);
    if (ret)
        return ret;

    args->handle = handle;
    return 0;
}

#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 12, 0)
int vbox_dumb_destroy(struct drm_file *file,
             struct drm_device *dev,
             uint32_t handle)
{
    return drm_gem_handle_delete(file, handle);
}
#endif

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

    if ((*bo) == NULL)
        return;

    tbo = &((*bo)->bo);
    ttm_bo_unref(&tbo);
    if (tbo == NULL)
        *bo = NULL;

}
void vbox_gem_free_object(struct drm_gem_object *obj)
{
    struct vbox_bo *vbox_bo = gem_to_vbox_bo(obj);

    vbox_bo_unref(&vbox_bo);
}


static inline u64 vbox_bo_mmap_offset(struct vbox_bo *bo)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 12, 0)
    return bo->bo.addr_space_offset;
#else
    return drm_vma_node_offset_addr(&bo->bo.vma_node);
#endif
}
int
vbox_dumb_mmap_offset(struct drm_file *file,
             struct drm_device *dev,
             uint32_t handle,
             uint64_t *offset)
{
    struct drm_gem_object *obj;
    int ret;
    struct vbox_bo *bo;

    mutex_lock(&dev->struct_mutex);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
    obj = drm_gem_object_lookup(file, handle);
#else
    obj = drm_gem_object_lookup(dev, file, handle);
#endif
    if (obj == NULL) {
        ret = -ENOENT;
        goto out_unlock;
    }

    bo = gem_to_vbox_bo(obj);
    *offset = vbox_bo_mmap_offset(bo);

    drm_gem_object_unreference(obj);
    ret = 0;
out_unlock:
    mutex_unlock(&dev->struct_mutex);
    return ret;

}