diff options
Diffstat (limited to 'drivers/gpu/drm/vgem/vgem_fence.c')
-rw-r--r-- | drivers/gpu/drm/vgem/vgem_fence.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vgem/vgem_fence.c b/drivers/gpu/drm/vgem/vgem_fence.c new file mode 100644 index 0000000..5c57c1f --- /dev/null +++ b/drivers/gpu/drm/vgem/vgem_fence.c @@ -0,0 +1,283 @@ +/* + * 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/reservation.h> + +#include "vgem_drv.h" + +#define VGEM_FENCE_TIMEOUT (10*HZ) + +struct vgem_fence { + struct fence base; + struct spinlock lock; + struct timer_list timer; +}; + +static const char *vgem_fence_get_driver_name(struct fence *fence) +{ + return "vgem"; +} + +static const char *vgem_fence_get_timeline_name(struct fence *fence) +{ + return "unbound"; +} + +static bool vgem_fence_signaled(struct fence *fence) +{ + return false; +} + +static bool vgem_fence_enable_signaling(struct fence *fence) +{ + return true; +} + +static void vgem_fence_release(struct fence *base) +{ + struct vgem_fence *fence = container_of(base, typeof(*fence), base); + + del_timer_sync(&fence->timer); + fence_free(&fence->base); +} + +static void vgem_fence_value_str(struct fence *fence, char *str, int size) +{ + snprintf(str, size, "%u", fence->seqno); +} + +static void vgem_fence_timeline_value_str(struct fence *fence, char *str, + int size) +{ + snprintf(str, size, "%u", fence_is_signaled(fence) ? fence->seqno : 0); +} + +static const struct fence_ops vgem_fence_ops = { + .get_driver_name = vgem_fence_get_driver_name, + .get_timeline_name = vgem_fence_get_timeline_name, + .enable_signaling = vgem_fence_enable_signaling, + .signaled = vgem_fence_signaled, + .wait = fence_default_wait, + .release = vgem_fence_release, + + .fence_value_str = vgem_fence_value_str, + .timeline_value_str = vgem_fence_timeline_value_str, +}; + +static void vgem_fence_timeout(unsigned long data) +{ + struct vgem_fence *fence = (struct vgem_fence *)data; + + fence_signal(&fence->base); +} + +static struct 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); + fence_init(&fence->base, &vgem_fence_ops, &fence->lock, + fence_context_alloc(1), 1); + + setup_timer(&fence->timer, vgem_fence_timeout, (unsigned long)fence); + + /* We force the fence to expire within 10s to prevent driver hangs */ + mod_timer(&fence->timer, jiffies + VGEM_FENCE_TIMEOUT); + + return &fence->base; +} + +static int attach_dmabuf(struct drm_device *dev, + struct drm_gem_object *obj) +{ + struct dma_buf *dmabuf; + + if (obj->dma_buf) + return 0; + + dmabuf = dev->driver->gem_prime_export(dev, obj, 0); + if (IS_ERR(dmabuf)) + return PTR_ERR(dmabuf); + + obj->dma_buf = dmabuf; + drm_gem_object_reference(obj); + return 0; +} + +/* + * 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 reservation_object *resv; + struct drm_gem_object *obj; + struct 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; + + ret = attach_dmabuf(dev, obj); + if (ret) + goto err; + + fence = vgem_fence_create(vfile, arg->flags); + if (!fence) { + ret = -ENOMEM; + goto err; + } + + /* Check for a conflicting fence */ + resv = obj->dma_buf->resv; + if (!reservation_object_test_signaled_rcu(resv, + arg->flags & VGEM_FENCE_WRITE)) { + ret = -EBUSY; + goto err_fence; + } + + /* Expose the fence via the dma-buf */ + ret = 0; + mutex_lock(&resv->lock.base); + if (arg->flags & VGEM_FENCE_WRITE) + reservation_object_add_excl_fence(resv, fence); + else if ((ret = reservation_object_reserve_shared(resv)) == 0) + reservation_object_add_shared_fence(resv, fence); + mutex_unlock(&resv->lock.base); + + /* 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) { + fence_signal(fence); + fence_put(fence); + } +err: + drm_gem_object_unreference_unlocked(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 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 (fence_is_signaled(fence)) + ret = -ETIMEDOUT; + + fence_signal(fence); + fence_put(fence); + return ret; +} + +int vgem_fence_open(struct vgem_file *vfile) +{ + mutex_init(&vfile->fence_mutex); + idr_init(&vfile->fence_idr); + + return 0; +} + +static int __vgem_fence_idr_fini(int id, void *p, void *data) +{ + fence_signal(p); + 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); +} |