v2: Only allow the new IOCTLs on the buffer FD created with
IIO_BUFFER_GET_FD_IOCTL().
Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---
drivers/iio/industrialio-buffer.c | 55
+++++++++++++++++++++++++++++++
include/linux/iio/buffer_impl.h | 8 +++++
include/uapi/linux/iio/buffer.h | 29 ++++++++++++++++
3 files changed, 92 insertions(+)
diff --git a/drivers/iio/industrialio-buffer.c
b/drivers/iio/industrialio-buffer.c
index 94eb9f6cf128..72f333a519bc 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -17,6 +17,7 @@
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/slab.h>
+#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/sched/signal.h>
@@ -1520,11 +1521,65 @@ static int iio_buffer_chrdev_release(struct
inode *inode, struct file *filep)
return 0;
}
+static int iio_buffer_enqueue_dmabuf(struct iio_buffer *buffer,
+ struct iio_dmabuf __user *user_buf)
+{
+ struct iio_dmabuf dmabuf;
+
+ if (!buffer->access->enqueue_dmabuf)
+ return -EPERM;
+
+ if (copy_from_user(&dmabuf, user_buf, sizeof(dmabuf)))
+ return -EFAULT;
+
+ if (dmabuf.flags & ~IIO_BUFFER_DMABUF_SUPPORTED_FLAGS)
+ return -EINVAL;
+
+ return buffer->access->enqueue_dmabuf(buffer, &dmabuf);
+}
+
+static int iio_buffer_alloc_dmabuf(struct iio_buffer *buffer,
+ struct iio_dmabuf_alloc_req __user *user_req)
+{
+ struct iio_dmabuf_alloc_req req;
+
+ if (!buffer->access->alloc_dmabuf)
+ return -EPERM;
+
+ if (copy_from_user(&req, user_req, sizeof(req)))
+ return -EFAULT;
+
+ if (req.resv)
+ return -EINVAL;
+
+ return buffer->access->alloc_dmabuf(buffer, &req);
+}
+
+static long iio_buffer_chrdev_ioctl(struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct iio_dev_buffer_pair *ib = filp->private_data;
+ struct iio_buffer *buffer = ib->buffer;
+ void __user *_arg = (void __user *)arg;
+
+ switch (cmd) {
+ case IIO_BUFFER_DMABUF_ALLOC_IOCTL:
+ return iio_buffer_alloc_dmabuf(buffer, _arg);
+ case IIO_BUFFER_DMABUF_ENQUEUE_IOCTL:
+ /* TODO: support non-blocking enqueue operation */
+ return iio_buffer_enqueue_dmabuf(buffer, _arg);
+ default:
+ return IIO_IOCTL_UNHANDLED;
+ }
+}
+
static const struct file_operations iio_buffer_chrdev_fileops = {
.owner = THIS_MODULE,
.llseek = noop_llseek,
.read = iio_buffer_read,
.write = iio_buffer_write,
+ .unlocked_ioctl = iio_buffer_chrdev_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
.poll = iio_buffer_poll,
.release = iio_buffer_chrdev_release,
};
diff --git a/include/linux/iio/buffer_impl.h
b/include/linux/iio/buffer_impl.h
index e2ca8ea23e19..728541bc2c63 100644
--- a/include/linux/iio/buffer_impl.h
+++ b/include/linux/iio/buffer_impl.h
@@ -39,6 +39,9 @@ struct iio_buffer;
* device stops sampling. Calles are balanced
with @enable.
* @release: called when the last reference to the buffer is
dropped,
* should free all resources allocated by the buffer.
+ * @alloc_dmabuf: called from userspace via ioctl to allocate one
DMABUF.
+ * @enqueue_dmabuf: called from userspace via ioctl to queue this
DMABUF
+ * object to this buffer. Requires a valid DMABUF fd.
* @modes: Supported operating modes by this buffer type
* @flags: A bitmask combination of INDIO_BUFFER_FLAG_*
*
@@ -68,6 +71,11 @@ struct iio_buffer_access_funcs {
void (*release)(struct iio_buffer *buffer);
+ int (*alloc_dmabuf)(struct iio_buffer *buffer,
+ struct iio_dmabuf_alloc_req *req);
+ int (*enqueue_dmabuf)(struct iio_buffer *buffer,
+ struct iio_dmabuf *block);
+
unsigned int modes;
unsigned int flags;
};
diff --git a/include/uapi/linux/iio/buffer.h
b/include/uapi/linux/iio/buffer.h
index 13939032b3f6..e4621b926262 100644
--- a/include/uapi/linux/iio/buffer.h
+++ b/include/uapi/linux/iio/buffer.h
@@ -5,6 +5,35 @@
#ifndef _UAPI_IIO_BUFFER_H_
#define _UAPI_IIO_BUFFER_H_
+#include <linux/types.h>
+
+#define IIO_BUFFER_DMABUF_SUPPORTED_FLAGS 0x00000000
+
+/**
+ * struct iio_dmabuf_alloc_req - Descriptor for allocating IIO
DMABUFs
+ * @size: the size of a single DMABUF
+ * @resv: reserved
+ */
+struct iio_dmabuf_alloc_req {
+ __u64 size;
+ __u64 resv;
+};
+
+/**
+ * struct iio_dmabuf - Descriptor for a single IIO DMABUF object
+ * @fd: file descriptor of the DMABUF object
+ * @flags: one or more IIO_BUFFER_DMABUF_* flags
+ * @bytes_used: number of bytes used in this DMABUF for the data
transfer.
+ * If zero, the full buffer is used.
+ */
+struct iio_dmabuf {
+ __u32 fd;
+ __u32 flags;
+ __u64 bytes_used;
+};
+
#define IIO_BUFFER_GET_FD_IOCTL _IOWR('i', 0x91, int)
+#define IIO_BUFFER_DMABUF_ALLOC_IOCTL _IOW('i', 0x92, struct
iio_dmabuf_alloc_req)
+#define IIO_BUFFER_DMABUF_ENQUEUE_IOCTL _IOW('i', 0x93, struct
iio_dmabuf)
#endif /* _UAPI_IIO_BUFFER_H_ */
