| Message ID | 20140217155832.20337.83163.stgit@patser (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Feb 17, 2014 at 10:58 AM, Maarten Lankhorst <maarten.lankhorst@canonical.com> wrote: > Thanks to Fengguang Wu for spotting a missing static cast. > > v2: > - Kill unused variable need_shared. > > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> > --- > drivers/base/dma-buf.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/dma-buf.h | 12 ++++++ > 2 files changed, 113 insertions(+) > > diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c > index 85e792c2c909..77ea621ab59d 100644 > --- a/drivers/base/dma-buf.c > +++ b/drivers/base/dma-buf.c > @@ -30,6 +30,7 @@ > #include <linux/export.h> > #include <linux/debugfs.h> > #include <linux/seq_file.h> > +#include <linux/poll.h> > #include <linux/reservation.h> > > static inline int is_dma_buf_file(struct file *); > @@ -52,6 +53,13 @@ static int dma_buf_release(struct inode *inode, struct file *file) > > BUG_ON(dmabuf->vmapping_counter); > > + /* > + * Any fences that a dma-buf poll can wait on should be signaled > + * before releasing dma-buf. This is the responsibility of each > + * driver that uses the reservation objects. minor nit.. but wouldn't hurt to mention in the comment that if you hit this BUG_ON it is because someone isn't holding a ref to the dmabuf while there is a pending fence > + */ > + BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); > + > dmabuf->ops->release(dmabuf); > > mutex_lock(&db_list.lock); > @@ -108,10 +116,99 @@ static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) > return base + offset; > } > > +static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) > +{ > + struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t*) cb; > + unsigned long flags; > + > + spin_lock_irqsave(&dcb->poll->lock, flags); > + wake_up_locked_poll(dcb->poll, dcb->active); > + dcb->active = 0; > + spin_unlock_irqrestore(&dcb->poll->lock, flags); > +} > + > +static unsigned int dma_buf_poll(struct file *file, poll_table *poll) > +{ > + struct dma_buf *dmabuf; > + struct reservation_object *resv; > + unsigned long events; > + > + dmabuf = file->private_data; > + if (!dmabuf || !dmabuf->resv) > + return POLLERR; > + > + resv = dmabuf->resv; > + > + poll_wait(file, &dmabuf->poll, poll); > + > + events = poll_requested_events(poll) & (POLLIN | POLLOUT); > + if (!events) > + return 0; > + > + ww_mutex_lock(&resv->lock, NULL); > + > + if (resv->fence_excl && (!(events & POLLOUT) || resv->fence_shared_count == 0)) { > + struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; > + unsigned long pevents = POLLIN; > + > + if (resv->fence_shared_count == 0) > + pevents |= POLLOUT; > + > + spin_lock_irq(&dmabuf->poll.lock); > + if (dcb->active) { > + dcb->active |= pevents; > + events &= ~pevents; > + } else > + dcb->active = pevents; > + spin_unlock_irq(&dmabuf->poll.lock); > + > + if (events & pevents) { > + if (!fence_add_callback(resv->fence_excl, > + &dcb->cb, dma_buf_poll_cb)) > + events &= ~pevents; > + else > + // No callback queued, wake up any additional waiters. couple spots w/ c++ comments, which I assume you didn't mean to leave? Anyways, other than those minor things, Reviewed-by: Rob Clark <robdclark@gmail.com> > + dma_buf_poll_cb(NULL, &dcb->cb); > + } > + } > + > + if ((events & POLLOUT) && resv->fence_shared_count > 0) { > + struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; > + int i; > + > + /* Only queue a new callback if no event has fired yet */ > + spin_lock_irq(&dmabuf->poll.lock); > + if (dcb->active) > + events &= ~POLLOUT; > + else > + dcb->active = POLLOUT; > + spin_unlock_irq(&dmabuf->poll.lock); > + > + if (!(events & POLLOUT)) > + goto out; > + > + for (i = 0; i < resv->fence_shared_count; ++i) > + if (!fence_add_callback(resv->fence_shared[i], > + &dcb->cb, dma_buf_poll_cb)) { > + events &= ~POLLOUT; > + break; > + } > + > + // No callback queued, wake up any additional waiters. > + if (i == resv->fence_shared_count) > + dma_buf_poll_cb(NULL, &dcb->cb); > + } > + > +out: > + ww_mutex_unlock(&resv->lock); > + return events; > +} > + > static const struct file_operations dma_buf_fops = { > .release = dma_buf_release, > .mmap = dma_buf_mmap_internal, > .llseek = dma_buf_llseek, > + .poll = dma_buf_poll, > }; > > /* > @@ -171,6 +268,10 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, > dmabuf->ops = ops; > dmabuf->size = size; > dmabuf->exp_name = exp_name; > + init_waitqueue_head(&dmabuf->poll); > + dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; > + dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; > + > if (!resv) { > resv = (struct reservation_object*)&dmabuf[1]; > reservation_object_init(resv); > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > index 34cfbac52c03..e1df18f584ef 100644 > --- a/include/linux/dma-buf.h > +++ b/include/linux/dma-buf.h > @@ -30,6 +30,8 @@ > #include <linux/list.h> > #include <linux/dma-mapping.h> > #include <linux/fs.h> > +#include <linux/fence.h> > +#include <linux/wait.h> > > struct device; > struct dma_buf; > @@ -130,6 +132,16 @@ struct dma_buf { > struct list_head list_node; > void *priv; > struct reservation_object *resv; > + > + /* poll support */ > + wait_queue_head_t poll; > + > + struct dma_buf_poll_cb_t { > + struct fence_cb cb; > + wait_queue_head_t *poll; > + > + unsigned long active; > + } cb_excl, cb_shared; > }; > > /** >
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 85e792c2c909..77ea621ab59d 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -30,6 +30,7 @@ #include <linux/export.h> #include <linux/debugfs.h> #include <linux/seq_file.h> +#include <linux/poll.h> #include <linux/reservation.h> static inline int is_dma_buf_file(struct file *); @@ -52,6 +53,13 @@ static int dma_buf_release(struct inode *inode, struct file *file) BUG_ON(dmabuf->vmapping_counter); + /* + * Any fences that a dma-buf poll can wait on should be signaled + * before releasing dma-buf. This is the responsibility of each + * driver that uses the reservation objects. + */ + BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); + dmabuf->ops->release(dmabuf); mutex_lock(&db_list.lock); @@ -108,10 +116,99 @@ static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence) return base + offset; } +static void dma_buf_poll_cb(struct fence *fence, struct fence_cb *cb) +{ + struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t*) cb; + unsigned long flags; + + spin_lock_irqsave(&dcb->poll->lock, flags); + wake_up_locked_poll(dcb->poll, dcb->active); + dcb->active = 0; + spin_unlock_irqrestore(&dcb->poll->lock, flags); +} + +static unsigned int dma_buf_poll(struct file *file, poll_table *poll) +{ + struct dma_buf *dmabuf; + struct reservation_object *resv; + unsigned long events; + + dmabuf = file->private_data; + if (!dmabuf || !dmabuf->resv) + return POLLERR; + + resv = dmabuf->resv; + + poll_wait(file, &dmabuf->poll, poll); + + events = poll_requested_events(poll) & (POLLIN | POLLOUT); + if (!events) + return 0; + + ww_mutex_lock(&resv->lock, NULL); + + if (resv->fence_excl && (!(events & POLLOUT) || resv->fence_shared_count == 0)) { + struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl; + unsigned long pevents = POLLIN; + + if (resv->fence_shared_count == 0) + pevents |= POLLOUT; + + spin_lock_irq(&dmabuf->poll.lock); + if (dcb->active) { + dcb->active |= pevents; + events &= ~pevents; + } else + dcb->active = pevents; + spin_unlock_irq(&dmabuf->poll.lock); + + if (events & pevents) { + if (!fence_add_callback(resv->fence_excl, + &dcb->cb, dma_buf_poll_cb)) + events &= ~pevents; + else + // No callback queued, wake up any additional waiters. + dma_buf_poll_cb(NULL, &dcb->cb); + } + } + + if ((events & POLLOUT) && resv->fence_shared_count > 0) { + struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared; + int i; + + /* Only queue a new callback if no event has fired yet */ + spin_lock_irq(&dmabuf->poll.lock); + if (dcb->active) + events &= ~POLLOUT; + else + dcb->active = POLLOUT; + spin_unlock_irq(&dmabuf->poll.lock); + + if (!(events & POLLOUT)) + goto out; + + for (i = 0; i < resv->fence_shared_count; ++i) + if (!fence_add_callback(resv->fence_shared[i], + &dcb->cb, dma_buf_poll_cb)) { + events &= ~POLLOUT; + break; + } + + // No callback queued, wake up any additional waiters. + if (i == resv->fence_shared_count) + dma_buf_poll_cb(NULL, &dcb->cb); + } + +out: + ww_mutex_unlock(&resv->lock); + return events; +} + static const struct file_operations dma_buf_fops = { .release = dma_buf_release, .mmap = dma_buf_mmap_internal, .llseek = dma_buf_llseek, + .poll = dma_buf_poll, }; /* @@ -171,6 +268,10 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, dmabuf->ops = ops; dmabuf->size = size; dmabuf->exp_name = exp_name; + init_waitqueue_head(&dmabuf->poll); + dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; + dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; + if (!resv) { resv = (struct reservation_object*)&dmabuf[1]; reservation_object_init(resv); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 34cfbac52c03..e1df18f584ef 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -30,6 +30,8 @@ #include <linux/list.h> #include <linux/dma-mapping.h> #include <linux/fs.h> +#include <linux/fence.h> +#include <linux/wait.h> struct device; struct dma_buf; @@ -130,6 +132,16 @@ struct dma_buf { struct list_head list_node; void *priv; struct reservation_object *resv; + + /* poll support */ + wait_queue_head_t poll; + + struct dma_buf_poll_cb_t { + struct fence_cb cb; + wait_queue_head_t *poll; + + unsigned long active; + } cb_excl, cb_shared; }; /**
Thanks to Fengguang Wu for spotting a missing static cast. v2: - Kill unused variable need_shared. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> --- drivers/base/dma-buf.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 12 ++++++ 2 files changed, 113 insertions(+)