linux_kernel/drivers/gpu/drm/vmwgfx/vmwgfx_dmabuf.c

// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
 *
 * Copyright 2011-2015 VMware, Inc., Palo Alto, CA., USA
 *
 * 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_operation_ctx ctx = {interruptible, false };
	struct ttm_buffer_object *bo = &buf->base;
	int ret;
	uint32_t new_flags;

	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, NULL);
	if (unlikely(ret != 0))
		goto err;

	if (buf->pin_count > 0)
		ret = ttm_bo_mem_compat(placement, &bo->mem,
					&new_flags) == true ? 0 : -EINVAL;
	else
		ret = ttm_bo_validate(bo, placement, &ctx);

	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_operation_ctx ctx = {interruptible, false };
	struct ttm_buffer_object *bo = &buf->base;
	int ret;
	uint32_t new_flags;

	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, NULL);
	if (unlikely(ret != 0))
		goto err;

	if (buf->pin_count > 0) {
		ret = ttm_bo_mem_compat(&vmw_vram_gmr_placement, &bo->mem,
					&new_flags) == true ? 0 : -EINVAL;
		goto out_unreserve;
	}

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

	ret = ttm_bo_validate(bo, &vmw_vram_placement, &ctx);

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_operation_ctx ctx = {interruptible, false };
	struct ttm_buffer_object *bo = &buf->base;
	struct ttm_placement placement;
	struct ttm_place place;
	int ret = 0;
	uint32_t new_flags;

	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, 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 &&
	    buf->pin_count == 0) {
		ctx.interruptible = false;
		(void) ttm_bo_validate(bo, &vmw_sys_placement, &ctx);
	}

	if (buf->pin_count > 0)
		ret = ttm_bo_mem_compat(&placement, &bo->mem,
					&new_flags) == true ? 0 : -EINVAL;
	else
		ret = ttm_bo_validate(bo, &placement, &ctx);

	/* 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, 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_operation_ctx ctx = { false, true };
	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, &ctx);

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


/*
 * vmw_dma_buffer_unmap - Tear down a cached buffer object map.
 *
 * @vbo: The buffer object whose map we are tearing down.
 *
 * This function tears down a cached map set up using
 * vmw_dma_buffer_map_and_cache().
 */
void vmw_dma_buffer_unmap(struct vmw_dma_buffer *vbo)
{
	if (vbo->map.bo == NULL)
		return;

	ttm_bo_kunmap(&vbo->map);
}


/*
 * vmw_dma_buffer_map_and_cache - Map a buffer object and cache the map
 *
 * @vbo: The buffer object to map
 * Return: A kernel virtual address or NULL if mapping failed.
 *
 * This function maps a buffer object into the kernel address space, or
 * returns the virtual kernel address of an already existing map. The virtual
 * address remains valid as long as the buffer object is pinned or reserved.
 * The cached map is torn down on either
 * 1) Buffer object move
 * 2) Buffer object swapout
 * 3) Buffer object destruction
 *
 */
void *vmw_dma_buffer_map_and_cache(struct vmw_dma_buffer *vbo)
{
	struct ttm_buffer_object *bo = &vbo->base;
	bool not_used;
	void *virtual;
	int ret;

	virtual = ttm_kmap_obj_virtual(&vbo->map, &not_used);
	if (virtual)
		return virtual;

	ret = ttm_bo_kmap(bo, 0, bo->num_pages, &vbo->map);
	if (ret)
		DRM_ERROR("Buffer object map failed: %d.\n", ret);

	return ttm_kmap_obj_virtual(&vbo->map, &not_used);
}