From: Hans de Goede <hdego...@redhat.com>
This allows userspace to use bulk-streams, just like in kernel drivers, see
Documentation/usb/bulk-streams.txt for details on the in kernel API. This
is exported pretty much one on one to userspace.
To use streams an app must first make a USBDEVFS_ALLOC_STREAMS ioctl,
on success this will return the number of streams available (which may be
less then requested). If there are n streams the app can then submit
usbdevfs_urb-s with their stream_id member set to 1-n to use a specific
stream. IE if USBDEVFS_ALLOC_STREAMS returns 4 then stream_id 1-4 can be
used.
When the app is done using streams it should call USBDEVFS_FREE_STREAMS
Note applications are advised to use libusb rather then using the
usbdevfs api directly. The latest version of libusb has support for streams.
Signed-off-by: Hans de Goede <hdego...@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sh...@linux.intel.com>
---
drivers/usb/core/devio.c | 118 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/usbdevice_fs.h | 7 +++
2 files changed, 125 insertions(+)
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 502974b4deb5..12401ee4ba0e 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -778,6 +778,79 @@ static struct usb_host_endpoint
*ep_to_host_endpoint(struct usb_device *dev,
return dev->ep_out[ep & USB_ENDPOINT_NUMBER_MASK];
}
+static int parse_usbdevfs_streams(struct dev_state *ps,
+ struct usbdevfs_streams __user *streams,
+ unsigned int *num_streams_ret,
+ unsigned int *num_eps_ret,
+ struct usb_host_endpoint ***eps_ret,
+ struct usb_interface **intf_ret)
+{
+ unsigned int i, num_streams, num_eps;
+ struct usb_host_endpoint **eps;
+ struct usb_interface *intf = NULL;
+ unsigned char ep;
+ int ifnum, ret;
+
+ if (get_user(num_streams, &streams->num_streams) ||
+ get_user(num_eps, &streams->num_eps))
+ return -EFAULT;
+
+ if (num_eps < 1 || num_eps > USB_MAXENDPOINTS)
+ return -EINVAL;
+
+ /* The XHCI controller allows max 2 ^ 16 streams */
+ if (num_streams_ret && (num_streams < 2 || num_streams > 65536))
+ return -EINVAL;
+
+ eps = kmalloc(num_eps * sizeof(*eps), GFP_KERNEL);
+ if (!eps)
+ return -ENOMEM;
+
+ for (i = 0; i < num_eps; i++) {
+ if (get_user(ep, &streams->eps[i])) {
+ ret = -EFAULT;
+ goto error;
+ }
+ eps[i] = ep_to_host_endpoint(ps->dev, ep);
+ if (!eps[i]) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ /* usb_alloc/free_streams operate on an usb_interface */
+ ifnum = findintfep(ps->dev, ep);
+ if (ifnum < 0) {
+ ret = ifnum;
+ goto error;
+ }
+
+ if (i == 0) {
+ ret = checkintf(ps, ifnum);
+ if (ret < 0)
+ goto error;
+ intf = usb_ifnum_to_if(ps->dev, ifnum);
+ } else {
+ /* Verify all eps belong to the same interface */
+ if (ifnum != intf->altsetting->desc.bInterfaceNumber) {
+ ret = -EINVAL;
+ goto error;
+ }
+ }
+ }
+
+ if (num_streams_ret)
+ *num_streams_ret = num_streams;
+ *num_eps_ret = num_eps;
+ *eps_ret = eps;
+ *intf_ret = intf;
+
+ return 0;
+
+error:
+ kfree(eps);
+ return ret;
+}
+
static int match_devt(struct device *dev, void *data)
{
return dev->devt == (dev_t) (unsigned long) data;
@@ -2009,6 +2082,45 @@ static int proc_disconnect_claim(struct dev_state *ps,
void __user *arg)
return claimintf(ps, dc.interface);
}
+static int proc_alloc_streams(struct dev_state *ps, void __user *arg)
+{
+ unsigned num_streams, num_eps;
+ struct usb_host_endpoint **eps;
+ struct usb_interface *intf;
+ int r;
+
+ r = parse_usbdevfs_streams(ps, arg, &num_streams, &num_eps,
+ &eps, &intf);
+ if (r)
+ return r;
+
+ destroy_async_on_interface(ps,
+ intf->altsetting[0].desc.bInterfaceNumber);
+
+ r = usb_alloc_streams(intf, eps, num_eps, num_streams, GFP_KERNEL);
+ kfree(eps);
+ return r;
+}
+
+static int proc_free_streams(struct dev_state *ps, void __user *arg)
+{
+ unsigned num_eps;
+ struct usb_host_endpoint **eps;
+ struct usb_interface *intf;
+ int r;
+
+ r = parse_usbdevfs_streams(ps, arg, NULL, &num_eps, &eps, &intf);
+ if (r)
+ return r;
+
+ destroy_async_on_interface(ps,
+ intf->altsetting[0].desc.bInterfaceNumber);
+
+ r = usb_free_streams(intf, eps, num_eps, GFP_KERNEL);
+ kfree(eps);
+ return r;
+}
+
/*
* NOTE: All requests here that have interface numbers as parameters
* are assuming that somehow the configuration has been prevented from
@@ -2185,6 +2297,12 @@ static long usbdev_do_ioctl(struct file *file, unsigned
int cmd,
case USBDEVFS_DISCONNECT_CLAIM:
ret = proc_disconnect_claim(ps, p);
break;
+ case USBDEVFS_ALLOC_STREAMS:
+ ret = proc_alloc_streams(ps, p);
+ break;
+ case USBDEVFS_FREE_STREAMS:
+ ret = proc_free_streams(ps, p);
+ break;
}
usb_unlock_device(dev);
if (ret >= 0)
diff --git a/include/uapi/linux/usbdevice_fs.h
b/include/uapi/linux/usbdevice_fs.h
index cbf122db56bc..abe5f4bd4d82 100644
--- a/include/uapi/linux/usbdevice_fs.h
+++ b/include/uapi/linux/usbdevice_fs.h
@@ -147,6 +147,11 @@ struct usbdevfs_disconnect_claim {
char driver[USBDEVFS_MAXDRIVERNAME + 1];
};
+struct usbdevfs_streams {
+ unsigned int num_streams; /* Not used by USBDEVFS_FREE_STREAMS */
+ unsigned int num_eps;
+ unsigned char eps[0];
+};
#define USBDEVFS_CONTROL _IOWR('U', 0, struct usbdevfs_ctrltransfer)
#define USBDEVFS_CONTROL32 _IOWR('U', 0, struct
usbdevfs_ctrltransfer32)
@@ -179,5 +184,7 @@ struct usbdevfs_disconnect_claim {
#define USBDEVFS_RELEASE_PORT _IOR('U', 25, unsigned int)
#define USBDEVFS_GET_CAPABILITIES _IOR('U', 26, __u32)
#define USBDEVFS_DISCONNECT_CLAIM _IOR('U', 27, struct
usbdevfs_disconnect_claim)
+#define USBDEVFS_ALLOC_STREAMS _IOR('U', 28, struct usbdevfs_streams)
+#define USBDEVFS_FREE_STREAMS _IOR('U', 29, struct usbdevfs_streams)
#endif /* _UAPI_LINUX_USBDEVICE_FS_H */
--
1.8.5.5
--
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