From: Daniel Vetter <daniel.vet...@ffwll.ch>
FIXME: Update kerneldoc for begin/end to make it clear that those are
for mmap too.
Open: Do we need a special indication that the begin/end is from
userspace mmap and not from kernel mmap?
There's also the question already about kernel internal users - vmap
and kmap interfaces are much different ... We might need to add a
mapping enum to the begin/end dma-buf functions.
v2 (Tiago): Fix header file type names (u64 -> __u64)
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Signed-off-by: Tiago Vignatti <tiago.vignatti at intel.com>
---
drivers/dma-buf/dma-buf.c | 47 ++++++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/dma-buf.h | 39 ++++++++++++++++++++++++++++++++++++
2 files changed, 86 insertions(+)
create mode 100644 include/uapi/linux/dma-buf.h
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 155c146..4820d61 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -34,6 +34,8 @@
#include <linux/poll.h>
#include <linux/reservation.h>
+#include <uapi/linux/dma-buf.h>
+
static inline int is_dma_buf_file(struct file *);
struct dma_buf_list {
@@ -251,11 +253,56 @@ out:
return events;
}
+static long dma_buf_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct dma_buf *dmabuf;
+ struct dma_buf_sync sync;
+ enum dma_data_direction direction;
+
+ dmabuf = file->private_data;
+
+ if (!is_dma_buf_file(file))
+ return -EINVAL;
+
+ switch (cmd) {
+ case DMA_BUF_IOCTL_SYNC:
+ if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
+ return -EFAULT;
+
+ if (sync.flags & DMA_BUF_SYNC_RW)
+ direction = DMA_BIDIRECTIONAL;
+ else if (sync.flags & DMA_BUF_SYNC_READ)
+ direction = DMA_FROM_DEVICE;
+ else if (sync.flags & DMA_BUF_SYNC_WRITE)
+ direction = DMA_TO_DEVICE;
+ else
+ return -EINVAL;
+
+ if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
+ return -EINVAL;
+
+ /* FIXME: Check for overflows in start/length. */
+
+ if (sync.flags & DMA_BUF_SYNC_END)
+ dma_buf_end_cpu_access(dmabuf, sync.start,
+ sync.length, direction);
+ else
+ dma_buf_begin_cpu_access(dmabuf, sync.start,
+ sync.length, direction);
+
+ return 0;
+ default:
+ return -ENOTTY;
+ }
+}
+
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,
+ .unlocked_ioctl = dma_buf_ioctl,
};
/*
diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h
new file mode 100644
index 0000000..e5327df
--- /dev/null
+++ b/include/uapi/linux/dma-buf.h
@@ -0,0 +1,39 @@
+/*
+ * Framework for buffer objects that can be shared across devices/subsystems.
+ *
+ * Copyright(C) 2015 Intel Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _DMA_BUF_UAPI_H_
+#define _DMA_BUF_UAPI_H_
+
+struct dma_buf_sync {
+ __u64 flags;
+ __u64 start;
+ __u64 length;
+};
+
+#define DMA_BUF_SYNC_READ (1 << 0)
+#define DMA_BUF_SYNC_WRITE (2 << 0)
+#define DMA_BUF_SYNC_RW (3 << 0)
+#define DMA_BUF_SYNC_START (0 << 2)
+#define DMA_BUF_SYNC_END (1 << 2)
+#define DMA_BUF_SYNC_VALID_FLAGS_MASK \
+ (DMA_BUF_SYNC_RW | DMA_BUF_SYNC_END)
+
+#define DMA_BUF_BASE 'b'
+#define DMA_BUF_IOCTL_SYNC _IOWR(DMA_BUF_BASE, 0, struct dma_buf_sync)
+
+#endif
--
2.1.0
