/**************************************************************************
 *
 * Copyright © 2011-2015 VMware, Inc., Palo Alto, CA., USA
 * 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, 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 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 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.
 *
 **************************************************************************/

#include <drm/ttm/ttm_placement.h>

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


/**
 * vmw_dmabuf_pin_in_placement - Validate a buffer to placement.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to move.
 * @placement:  The placement to pin it.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 *  -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_pin_in_placement(struct vmw_private *dev_priv,
                                struct vmw_dma_buffer *buf,
                                struct ttm_placement *placement,
                                bool interruptible)
{
        struct ttm_buffer_object *bo = &buf->base;
        int ret;

        ret = ttm_write_lock(&dev_priv->reservation_sem, interruptible);
        if (unlikely(ret != 0))
                return ret;

        vmw_execbuf_release_pinned_bo(dev_priv);

        ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
        if (unlikely(ret != 0))
                goto err;

        ret = ttm_bo_validate(bo, placement, interruptible, false);
        if (!ret)
                vmw_bo_pin_reserved(buf, true);

        ttm_bo_unreserve(bo);

err:
        ttm_write_unlock(&dev_priv->reservation_sem);
        return ret;
}

/**
 * vmw_dmabuf_pin_in_vram_or_gmr - Move a buffer to vram or gmr.
 *
 * This function takes the reservation_sem in write mode.
 * Flushes and unpins the query bo to avoid failures.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to move.
 * @pin:  Pin buffer if true.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 * -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_pin_in_vram_or_gmr(struct vmw_private *dev_priv,
                                  struct vmw_dma_buffer *buf,
                                  bool interruptible)
{
        struct ttm_buffer_object *bo = &buf->base;
        int ret;

        ret = ttm_write_lock(&dev_priv->reservation_sem, interruptible);
        if (unlikely(ret != 0))
                return ret;

        vmw_execbuf_release_pinned_bo(dev_priv);

        ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
        if (unlikely(ret != 0))
                goto err;

        ret = ttm_bo_validate(bo, &vmw_vram_gmr_placement, interruptible,
                              false);
        if (likely(ret == 0) || ret == -ERESTARTSYS)
                goto out_unreserve;

        ret = ttm_bo_validate(bo, &vmw_vram_placement, interruptible, false);

out_unreserve:
        if (!ret)
                vmw_bo_pin_reserved(buf, true);

        ttm_bo_unreserve(bo);
err:
        ttm_write_unlock(&dev_priv->reservation_sem);
        return ret;
}

/**
 * vmw_dmabuf_pin_in_vram - Move a buffer to vram.
 *
 * This function takes the reservation_sem in write mode.
 * Flushes and unpins the query bo to avoid failures.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to move.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 * -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_pin_in_vram(struct vmw_private *dev_priv,
                           struct vmw_dma_buffer *buf,
                           bool interruptible)
{
        return vmw_dmabuf_pin_in_placement(dev_priv, buf, &vmw_vram_placement,
                                           interruptible);
}

/**
 * vmw_dmabuf_pin_in_start_of_vram - Move a buffer to start of vram.
 *
 * This function takes the reservation_sem in write mode.
 * Flushes and unpins the query bo to avoid failures.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to pin.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 * -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_pin_in_start_of_vram(struct vmw_private *dev_priv,
                                    struct vmw_dma_buffer *buf,
                                    bool interruptible)
{
        struct ttm_buffer_object *bo = &buf->base;
        struct ttm_placement placement;
        struct ttm_place place;
        int ret = 0;

        place = vmw_vram_placement.placement[0];
        place.lpfn = bo->num_pages;
        placement.num_placement = 1;
        placement.placement = &place;
        placement.num_busy_placement = 1;
        placement.busy_placement = &place;

        ret = ttm_write_lock(&dev_priv->reservation_sem, interruptible);
        if (unlikely(ret != 0))
                return ret;

        vmw_execbuf_release_pinned_bo(dev_priv);
        ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
        if (unlikely(ret != 0))
                goto err_unlock;

        /*
         * Is this buffer already in vram but not at the start of it?
         * In that case, evict it first because TTM isn't good at handling
         * that situation.
         */
        if (bo->mem.mem_type == TTM_PL_VRAM &&
            bo->mem.start < bo->num_pages &&
            bo->mem.start > 0)
                (void) ttm_bo_validate(bo, &vmw_sys_placement, false, false);

        ret = ttm_bo_validate(bo, &placement, interruptible, false);

        /* For some reason we didn't end up at the start of vram */
        WARN_ON(ret == 0 && bo->offset != 0);
        if (!ret)
                vmw_bo_pin_reserved(buf, true);

        ttm_bo_unreserve(bo);
err_unlock:
        ttm_write_unlock(&dev_priv->reservation_sem);

        return ret;
}

/**
 * vmw_dmabuf_unpin - Unpin the buffer given buffer, does not move the buffer.
 *
 * This function takes the reservation_sem in write mode.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to unpin.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 * -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_unpin(struct vmw_private *dev_priv,
                     struct vmw_dma_buffer *buf,
                     bool interruptible)
{
        struct ttm_buffer_object *bo = &buf->base;
        int ret;

        ret = ttm_read_lock(&dev_priv->reservation_sem, interruptible);
        if (unlikely(ret != 0))
                return ret;

        ret = ttm_bo_reserve(bo, interruptible, false, false, NULL);
        if (unlikely(ret != 0))
                goto err;

        vmw_bo_pin_reserved(buf, false);

        ttm_bo_unreserve(bo);

err:
        ttm_read_unlock(&dev_priv->reservation_sem);
        return ret;
}

/**
 * vmw_bo_get_guest_ptr - Get the guest ptr representing the current placement
 * of a buffer.
 *
 * @bo: Pointer to a struct ttm_buffer_object. Must be pinned or reserved.
 * @ptr: SVGAGuestPtr returning the result.
 */
void vmw_bo_get_guest_ptr(const struct ttm_buffer_object *bo,
                          SVGAGuestPtr *ptr)
{
        if (bo->mem.mem_type == TTM_PL_VRAM) {
                ptr->gmrId = SVGA_GMR_FRAMEBUFFER;
                ptr->offset = bo->offset;
        } else {
                ptr->gmrId = bo->mem.start;
                ptr->offset = 0;
        }
}


/**
 * vmw_bo_pin_reserved - Pin or unpin a buffer object without moving it.
 *
 * @vbo: The buffer object. Must be reserved.
 * @pin: Whether to pin or unpin.
 *
 */
void vmw_bo_pin_reserved(struct vmw_dma_buffer *vbo, bool pin)
{
        struct ttm_place pl;
        struct ttm_placement placement;
        struct ttm_buffer_object *bo = &vbo->base;
        uint32_t old_mem_type = bo->mem.mem_type;
        int ret;

        lockdep_assert_held(&bo->resv->lock.base);

        if (pin) {
                if (vbo->pin_count++ > 0)
                        return;
        } else {
                WARN_ON(vbo->pin_count <= 0);
                if (--vbo->pin_count > 0)
                        return;
        }

        pl.fpfn = 0;
        pl.lpfn = 0;
        pl.flags = TTM_PL_FLAG_VRAM | VMW_PL_FLAG_GMR | VMW_PL_FLAG_MOB
                | TTM_PL_FLAG_SYSTEM | TTM_PL_FLAG_CACHED;
        if (pin)
                pl.flags |= TTM_PL_FLAG_NO_EVICT;

        memset(&placement, 0, sizeof(placement));
        placement.num_placement = 1;
        placement.placement = &pl;

        ret = ttm_bo_validate(bo, &placement, false, true);

        BUG_ON(ret != 0 || bo->mem.mem_type != old_mem_type);
}