/* $Id: vbox_main.c 111043 2016-09-29 13:05:15Z fmehnert $ */
/** @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 <VBox/VBoxVideoGuest.h>
#include <VBox/VBoxVideo.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);

	LogFunc(("vboxvideo: %d: vbox_fb=%p, vbox_fb->obj=%p\n", __LINE__,
		 vbox_fb, 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;

	AssertLogRelReturnVoid(vbox->vbva_info != NULL);
	for (i = 0; i < vbox->num_crtcs; ++i) {
		if (vbox->vbva_info[i].pVBVA == NULL) {
			LogFunc(("vboxvideo: enabling VBVA.\n"));
			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))
				AssertReleaseMsgFailed(("VBoxVBVAEnable failed - heap allocation error, very old host or driver error.\n"));
		}
	}
}

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;

	LogFunc(("vboxvideo: %d: fb=%p, num_rects=%u, vbox=%p\n", __LINE__, fb,
		 num_rects, vbox));
	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);
	LogFunc(("vboxvideo: %d\n", __LINE__));
}

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;

	LogFunc(("vboxvideo: %d: dev=%p, vbox_fb=%p, obj=%p\n", __LINE__, dev,
		 vbox_fb, obj));
	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);
		LogFunc(("vboxvideo: %d\n", __LINE__));
		return ret;
	}
	LogFunc(("vboxvideo: %d\n", __LINE__));
	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;

	LogFunc(("vboxvideo: %d\n", __LINE__));
#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);
	}
	LogFunc(("vboxvideo: %d\n", __LINE__));
	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;
	LogFunc(("vboxvideo: %d: vbox=%p, vbox->num_crtcs=%u, vbox->vbva_info=%p\n", __LINE__, vbox, (unsigned)vbox->num_crtcs, vbox->vbva_info));
	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);
	LogFunc(("vboxvideo: %d: vbox->vbva_info=%p, vbox->available_vram_size=%u\n", __LINE__, vbox->vbva_info, (unsigned)vbox->available_vram_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;

	LogFunc(("vboxvideo: %d: dev=%p\n", __LINE__, dev));
	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;
	LogFunc(("vboxvideo: %d: vbox=%p, vbox->mapped_vram=%p, vbox->full_vram_size=%u\n", __LINE__, vbox, vbox->mapped_vram, (unsigned)vbox->full_vram_size));
	return 0;
out_free:
	vbox_driver_unload(dev);
	LogFunc(("vboxvideo: %d: ret=%d\n", __LINE__, ret));
	return ret;
}

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

	LogFunc(("vboxvideo: %d\n", __LINE__));
	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;
	LogFunc(("vboxvideo: %d\n", __LINE__));
	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;

	LogFunc(("vboxvideo: %d: dev=%p, size=%u, iskernel=%u\n", __LINE__,
		 dev, (unsigned)size, (unsigned)iskernel));
	*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;
	LogFunc(("vboxvideo: %d: obj=%p\n", __LINE__, obj));
	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;

	LogFunc(("vboxvideo: %d: args->width=%u, args->height=%u, args->bpp=%u\n", __LINE__, (unsigned)args->width, (unsigned)args->height, (unsigned)args->bpp));
	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;
	LogFunc(("vboxvideo: %d: args->handle=%u\n", __LINE__,
		 (unsigned)args->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)
{
	LogFunc(("vboxvideo: %d: dev=%p, handle=%u\n", __LINE__, dev,
		 (unsigned)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;

	LogFunc(("vboxvideo: %d: bo=%p\n", __LINE__, bo));
	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);

	LogFunc(("vboxvideo: %d: vbox_bo=%p\n", __LINE__, vbox_bo));
	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;

	LogFunc(("vboxvideo: %d: dev=%p, handle=%u\n", __LINE__,
		 dev, (unsigned)handle));
	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;
	LogFunc(("vboxvideo: %d: bo=%p, *offset=%llu\n", __LINE__,
		 bo, (unsigned long long)*offset));
out_unlock:
	mutex_unlock(&dev->struct_mutex);
	return ret;

}
