linux/drivers/gpu/drm/vgem/vgem_fence.c

/*
 * Copyright 2016 Intel Corporation
 *
 * 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
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * them 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 MERCHANTIBILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS 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 <linux/dma-buf.h>
#include <linux/dma-resv.h>

#include <drm/drm_file.h>

#include "vgem_drv.h"

#define VGEM_FENCE_TIMEOUT …

struct vgem_fence { … };

static const char *vgem_fence_get_driver_name(struct dma_fence *fence)
{ … }

static const char *vgem_fence_get_timeline_name(struct dma_fence *fence)
{ … }

static void vgem_fence_release(struct dma_fence *base)
{ … }

static void vgem_fence_value_str(struct dma_fence *fence, char *str, int size)
{ … }

static void vgem_fence_timeline_value_str(struct dma_fence *fence, char *str,
					  int size)
{ … }

static const struct dma_fence_ops vgem_fence_ops = …;

static void vgem_fence_timeout(struct timer_list *t)
{ … }

static struct dma_fence *vgem_fence_create(struct vgem_file *vfile,
					   unsigned int flags)
{ … }

/*
 * vgem_fence_attach_ioctl (DRM_IOCTL_VGEM_FENCE_ATTACH):
 *
 * Create and attach a fence to the vGEM handle. This fence is then exposed
 * via the dma-buf reservation object and visible to consumers of the exported
 * dma-buf. If the flags contain VGEM_FENCE_WRITE, the fence indicates the
 * vGEM buffer is being written to by the client and is exposed as an exclusive
 * fence, otherwise the fence indicates the client is current reading from the
 * buffer and all future writes should wait for the client to signal its
 * completion. Note that if a conflicting fence is already on the dma-buf (i.e.
 * an exclusive fence when adding a read, or any fence when adding a write),
 * -EBUSY is reported. Serialisation between operations should be handled
 * by waiting upon the dma-buf.
 *
 * This returns the handle for the new fence that must be signaled within 10
 * seconds (or otherwise it will automatically expire). See
 * vgem_fence_signal_ioctl (DRM_IOCTL_VGEM_FENCE_SIGNAL).
 *
 * If the vGEM handle does not exist, vgem_fence_attach_ioctl returns -ENOENT.
 */
int vgem_fence_attach_ioctl(struct drm_device *dev,
			    void *data,
			    struct drm_file *file)
{ … }

/*
 * vgem_fence_signal_ioctl (DRM_IOCTL_VGEM_FENCE_SIGNAL):
 *
 * Signal and consume a fence ealier attached to a vGEM handle using
 * vgem_fence_attach_ioctl (DRM_IOCTL_VGEM_FENCE_ATTACH).
 *
 * All fences must be signaled within 10s of attachment or otherwise they
 * will automatically expire (and a vgem_fence_signal_ioctl returns -ETIMEDOUT).
 *
 * Signaling a fence indicates to all consumers of the dma-buf that the
 * client has completed the operation associated with the fence, and that the
 * buffer is then ready for consumption.
 *
 * If the fence does not exist (or has already been signaled by the client),
 * vgem_fence_signal_ioctl returns -ENOENT.
 */
int vgem_fence_signal_ioctl(struct drm_device *dev,
			    void *data,
			    struct drm_file *file)
{ … }

int vgem_fence_open(struct vgem_file *vfile)
{ … }

static int __vgem_fence_idr_fini(int id, void *p, void *data)
{ … }

void vgem_fence_close(struct vgem_file *vfile)
{ … }