blob: e1575417839599f1cc7ea64848c56eec71d4e045 [file] [log] [blame]
/*
* 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 (10*HZ)
struct vgem_fence {
struct dma_fence base;
struct spinlock lock;
struct timer_list timer;
};
static const char *vgem_fence_get_driver_name(struct dma_fence *fence)
{
return "vgem";
}
static const char *vgem_fence_get_timeline_name(struct dma_fence *fence)
{
return "unbound";
}
static void vgem_fence_release(struct dma_fence *base)
{
struct vgem_fence *fence = container_of(base, typeof(*fence), base);
del_timer_sync(&fence->timer);
dma_fence_free(&fence->base);
}
static void vgem_fence_value_str(struct dma_fence *fence, char *str, int size)
{
snprintf(str, size, "%llu", fence->seqno);
}
static void vgem_fence_timeline_value_str(struct dma_fence *fence, char *str,
int size)
{
snprintf(str, size, "%llu",
dma_fence_is_signaled(fence) ? fence->seqno : 0);
}
static const struct dma_fence_ops vgem_fence_ops = {
.get_driver_name = vgem_fence_get_driver_name,
.get_timeline_name = vgem_fence_get_timeline_name,
.release = vgem_fence_release,
.fence_value_str = vgem_fence_value_str,
.timeline_value_str = vgem_fence_timeline_value_str,
};
static void vgem_fence_timeout(struct timer_list *t)
{
struct vgem_fence *fence = from_timer(fence, t, timer);
dma_fence_signal(&fence->base);
}
static struct dma_fence *vgem_fence_create(struct vgem_file *vfile,
unsigned int flags)
{
struct vgem_fence *fence;
fence = kzalloc(sizeof(*fence), GFP_KERNEL);
if (!fence)
return NULL;
spin_lock_init(&fence->lock);
dma_fence_init(&fence->base, &vgem_fence_ops, &fence->lock,
dma_fence_context_alloc(1), 1);
timer_setup(&fence->timer, vgem_fence_timeout, 0);
/* We force the fence to expire within 10s to prevent driver hangs */
mod_timer(&fence->timer, jiffies + VGEM_FENCE_TIMEOUT);
return &fence->base;
}
/*
* 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)
{
struct drm_vgem_fence_attach *arg = data;
struct vgem_file *vfile = file->driver_priv;
struct dma_resv *resv;
struct drm_gem_object *obj;
enum dma_resv_usage usage;
struct dma_fence *fence;
int ret;
if (arg->flags & ~VGEM_FENCE_WRITE)
return -EINVAL;
if (arg->pad)
return -EINVAL;
obj = drm_gem_object_lookup(file, arg->handle);
if (!obj)
return -ENOENT;
fence = vgem_fence_create(vfile, arg->flags);
if (!fence) {
ret = -ENOMEM;
goto err;
}
/* Check for a conflicting fence */
resv = obj->resv;
usage = dma_resv_usage_rw(arg->flags & VGEM_FENCE_WRITE);
if (!dma_resv_test_signaled(resv, usage)) {
ret = -EBUSY;
goto err_fence;
}
/* Expose the fence via the dma-buf */
dma_resv_lock(resv, NULL);
ret = dma_resv_reserve_fences(resv, 1);
if (!ret)
dma_resv_add_fence(resv, fence, arg->flags & VGEM_FENCE_WRITE ?
DMA_RESV_USAGE_WRITE : DMA_RESV_USAGE_READ);
dma_resv_unlock(resv);
/* Record the fence in our idr for later signaling */
if (ret == 0) {
mutex_lock(&vfile->fence_mutex);
ret = idr_alloc(&vfile->fence_idr, fence, 1, 0, GFP_KERNEL);
mutex_unlock(&vfile->fence_mutex);
if (ret > 0) {
arg->out_fence = ret;
ret = 0;
}
}
err_fence:
if (ret) {
dma_fence_signal(fence);
dma_fence_put(fence);
}
err:
drm_gem_object_put(obj);
return ret;
}
/*
* 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)
{
struct vgem_file *vfile = file->driver_priv;
struct drm_vgem_fence_signal *arg = data;
struct dma_fence *fence;
int ret = 0;
if (arg->flags)
return -EINVAL;
mutex_lock(&vfile->fence_mutex);
fence = idr_replace(&vfile->fence_idr, NULL, arg->fence);
mutex_unlock(&vfile->fence_mutex);
if (!fence)
return -ENOENT;
if (IS_ERR(fence))
return PTR_ERR(fence);
if (dma_fence_is_signaled(fence))
ret = -ETIMEDOUT;
dma_fence_signal(fence);
dma_fence_put(fence);
return ret;
}
int vgem_fence_open(struct vgem_file *vfile)
{
mutex_init(&vfile->fence_mutex);
idr_init_base(&vfile->fence_idr, 1);
return 0;
}
static int __vgem_fence_idr_fini(int id, void *p, void *data)
{
dma_fence_signal(p);
dma_fence_put(p);
return 0;
}
void vgem_fence_close(struct vgem_file *vfile)
{
idr_for_each(&vfile->fence_idr, __vgem_fence_idr_fini, vfile);
idr_destroy(&vfile->fence_idr);
mutex_destroy(&vfile->fence_mutex);
}