From patchwork Mon Feb 17 15:58:37 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maarten Lankhorst X-Patchwork-Id: 3663761 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0CF39BF13A for ; Mon, 17 Feb 2014 16:00:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 20F41201F7 for ; Mon, 17 Feb 2014 16:00:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1EBF2201F5 for ; Mon, 17 Feb 2014 16:00:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753406AbaBQP6o (ORCPT ); Mon, 17 Feb 2014 10:58:44 -0500 Received: from adelie.canonical.com ([91.189.90.139]:49684 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752252AbaBQP6l (ORCPT ); Mon, 17 Feb 2014 10:58:41 -0500 Received: from lillypilly.canonical.com ([91.189.89.62]) by adelie.canonical.com with esmtp (Exim 4.71 #1 (Debian)) id 1WFQac-000283-0L; Mon, 17 Feb 2014 15:58:38 +0000 Received: by lillypilly.canonical.com (Postfix, from userid 3489) id F2BDF26C26CA; Mon, 17 Feb 2014 15:58:37 +0000 (UTC) Subject: [PATCH 6/6] dma-buf: add poll support, v2 To: linux-kernel@vger.kernel.org From: Maarten Lankhorst Cc: linux-arch@vger.kernel.org, ccross@google.com, linaro-mm-sig@lists.linaro.org, robdclark@gmail.com, dri-devel@lists.freedesktop.org, daniel@ffwll.ch, sumit.semwal@linaro.org, linux-media@vger.kernel.org Date: Mon, 17 Feb 2014 16:58:37 +0100 Message-ID: <20140217155832.20337.83163.stgit@patser> In-Reply-To: <20140217155056.20337.25254.stgit@patser> References: <20140217155056.20337.25254.stgit@patser> User-Agent: StGit/0.15 MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Thanks to Fengguang Wu for spotting a missing static cast. v2: - Kill unused variable need_shared. Signed-off-by: Maarten Lankhorst Reviewed-by: Rob Clark --- drivers/base/dma-buf.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 12 ++++++ 2 files changed, 113 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html 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 #include #include +#include #include 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 #include #include +#include +#include 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; }; /**