/**************************************************************************
 *
 * Copyright © 2011 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_to_placement - Validate a buffer to placement.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to move.
 * @pin:  Pin buffer if true.
 * @interruptible:  Use interruptible wait.
 *
 * May only be called by the current master since it assumes that the
 * master lock is the current master's lock.
 * This function takes the master's lock in write mode.
 * Flushes and unpins the query bo to avoid failures.
 *
 * Returns
 *  -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_to_placement(struct vmw_private *dev_priv,
                            struct vmw_dma_buffer *buf,
                            struct ttm_placement *placement,
                            bool interruptible)
{
        struct vmw_master *vmaster = dev_priv->active_master;
        struct ttm_buffer_object *bo = &buf->base;
        int ret;

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

        vmw_execbuf_release_pinned_bo(dev_priv);

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

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

        ttm_bo_unreserve(bo);

err:
        ttm_write_unlock(&vmaster->lock);
        return ret;
}

/**
 * vmw_dmabuf_to_vram_or_gmr - Move a buffer to vram or gmr.
 *
 * May only be called by the current master since it assumes that the
 * master lock is the current master's lock.
 * This function takes the master's lock in write mode.
 * Flushes and unpins the query bo if @pin == true 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_to_vram_or_gmr(struct vmw_private *dev_priv,
                              struct vmw_dma_buffer *buf,
                              bool pin, bool interruptible)
{
        struct vmw_master *vmaster = dev_priv->active_master;
        struct ttm_buffer_object *bo = &buf->base;
        struct ttm_placement *placement;
        int ret;

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

        if (pin)
                vmw_execbuf_release_pinned_bo(dev_priv);

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

        /**
         * Put BO in VRAM if there is space, otherwise as a GMR.
         * If there is no space in VRAM and GMR ids are all used up,
         * start evicting GMRs to make room. If the DMA buffer can't be
         * used as a GMR, this will return -ENOMEM.
         */

        if (pin)
                placement = &vmw_vram_gmr_ne_placement;
        else
                placement = &vmw_vram_gmr_placement;

        ret = ttm_bo_validate(bo, placement, interruptible, false);
        if (likely(ret == 0) || ret == -ERESTARTSYS)
                goto err_unreserve;


        /**
         * If that failed, try VRAM again, this time evicting
         * previous contents.
         */

        if (pin)
                placement = &vmw_vram_ne_placement;
        else
                placement = &vmw_vram_placement;

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

err_unreserve:
        ttm_bo_unreserve(bo);
err:
        ttm_write_unlock(&vmaster->lock);
        return ret;
}

/**
 * vmw_dmabuf_to_vram - Move a buffer to vram.
 *
 * May only be called by the current master since it assumes that the
 * master lock is the current master's lock.
 * This function takes the master's lock in write mode.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to move.
 * @pin:  Pin buffer in vram if true.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 * -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_to_vram(struct vmw_private *dev_priv,
                       struct vmw_dma_buffer *buf,
                       bool pin, bool interruptible)
{
        struct ttm_placement *placement;

        if (pin)
                placement = &vmw_vram_ne_placement;
        else
                placement = &vmw_vram_placement;

        return vmw_dmabuf_to_placement(dev_priv, buf,
                                       placement,
                                       interruptible);
}

/**
 * vmw_dmabuf_to_start_of_vram - Move a buffer to start of vram.
 *
 * May only be called by the current master since it assumes that the
 * master lock is the current master's lock.
 * This function takes the master's lock in write mode.
 * Flushes and unpins the query bo if @pin == true to avoid failures.
 *
 * @dev_priv:  Driver private.
 * @buf:  DMA buffer to move.
 * @pin:  Pin buffer in vram if true.
 * @interruptible:  Use interruptible wait.
 *
 * Returns
 * -ERESTARTSYS if interrupted by a signal.
 */
int vmw_dmabuf_to_start_of_vram(struct vmw_private *dev_priv,
                                struct vmw_dma_buffer *buf,
                                bool pin, bool interruptible)
{
        struct vmw_master *vmaster = dev_priv->active_master;
        struct ttm_buffer_object *bo = &buf->base;
        struct ttm_placement placement;
        int ret = 0;

        if (pin)
                placement = vmw_vram_ne_placement;
        else
                placement = vmw_vram_placement;
        placement.lpfn = bo->num_pages;

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

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

        /* Is this buffer already in vram but not at the start of it? */
        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 up at the start of vram */
        WARN_ON(ret == 0 && bo->offset != 0);

        ttm_bo_unreserve(bo);
err_unlock:
        ttm_write_unlock(&vmaster->lock);

        return ret;
}


/**
 * vmw_dmabuf_upin - Unpin the buffer given buffer, does not move the buffer.
 *
 * May only be called by the current master since it assumes that the
 * master lock is the current master's lock.
 * This function takes the master's lock 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)
{
        /*
         * We could in theory early out if the buffer is
         * unpinned but we need to lock and reserve the buffer
         * anyways so we don't gain much by that.
         */
        return vmw_dmabuf_to_placement(dev_priv, buf,
                                       &vmw_evictable_placement,
                                       interruptible);
}


/**
 * 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 - Pin or unpin a buffer object without moving it.
 *
 * @bo: The buffer object. Must be reserved, and present either in VRAM
 * or GMR memory.
 * @pin: Whether to pin or unpin.
 *
 */
void vmw_bo_pin(struct ttm_buffer_object *bo, bool pin)
{
        uint32_t pl_flags;
        struct ttm_placement placement;
        uint32_t old_mem_type = bo->mem.mem_type;
        int ret;

        BUG_ON(!ttm_bo_is_reserved(bo));
        BUG_ON(old_mem_type != TTM_PL_VRAM &&
               old_mem_type != VMW_PL_GMR);

        pl_flags = TTM_PL_FLAG_VRAM | VMW_PL_FLAG_GMR | 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_flags;

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

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