From mboxrd@z Thu Jan 1 00:00:00 1970 From: Inki Dae Date: Wed, 10 Jul 2013 11:58:47 +0000 Subject: [RFC PATCH v1 2/2] dma-buf: add lock callback for fcntl system call. Message-Id: <1373457527-28263-3-git-send-email-inki.dae@samsung.com> List-Id: References: <1373457527-28263-1-git-send-email-inki.dae@samsung.com> In-Reply-To: <1373457527-28263-1-git-send-email-inki.dae@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org Cc: maarten.lankhorst@canonical.com, daniel@ffwll.ch, robdclark@gmail.com, kyungmin.park@samsung.com, myungjoo.ham@samsung.com, yj44.cho@samsung.com, Inki Dae This patch adds lock callback to dma buf file operations, and this callback will be called by fcntl system call. With this patch, fcntl system call can be used for buffer synchronization between CPU and CPU, and CPU and DMA in user mode. Signed-off-by: Inki Dae Signed-off-by: Kyungmin Park --- drivers/base/dma-buf.c | 34 ++++++++++++++++++++++++++++++++++ 1 files changed, 34 insertions(+), 0 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index fe39120..cd71447 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -31,6 +31,7 @@ #include #include #include +#include static inline int is_dma_buf_file(struct file *); @@ -82,9 +83,42 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma) return dmabuf->ops->mmap(dmabuf, vma); } +static int dma_buf_lock(struct file *file, int cmd, struct file_lock *fl) +{ + struct dma_buf *dmabuf; + unsigned int type; + bool wait = false; + + if (!is_dma_buf_file(file)) + return -EINVAL; + + dmabuf = file->private_data; + + if ((fl->fl_type & F_UNLCK) = F_UNLCK) { + dmabuf_sync_single_unlock(dmabuf); + return 0; + } + + /* convert flock type to dmabuf sync type. */ + if ((fl->fl_type & F_WRLCK) = F_WRLCK) + type = DMA_BUF_ACCESS_W; + else if ((fl->fl_type & F_RDLCK) = F_RDLCK) + type = DMA_BUF_ACCESS_R; + else + return -EINVAL; + + if (fl->fl_flags & FL_SLEEP) + wait = true; + + /* TODO. the locking to certain region should also be considered. */ + + return dmabuf_sync_single_lock(dmabuf, type, wait); +} + static const struct file_operations dma_buf_fops = { .release = dma_buf_release, .mmap = dma_buf_mmap_internal, + .lock = dma_buf_lock, }; /* -- 1.7.5.4