| /* |
| * 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; |
| 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; |
| if (!dma_resv_test_signaled(resv, arg->flags & VGEM_FENCE_WRITE)) { |
| ret = -EBUSY; |
| goto err_fence; |
| } |
| |
| /* Expose the fence via the dma-buf */ |
| ret = 0; |
| dma_resv_lock(resv, NULL); |
| if (arg->flags & VGEM_FENCE_WRITE) |
| dma_resv_add_excl_fence(resv, fence); |
| else if ((ret = dma_resv_reserve_shared(resv, 1)) == 0) |
| dma_resv_add_shared_fence(resv, fence); |
| 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); |
| } |