From bcf7f6e39335af4f03da8c26a98185fd49754fcc Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 9 Oct 2013 17:19:31 +0200 Subject: [PATCH] usbfs: Add support for allocating / freeing streams 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 Signed-off-by: Sarah Sharp --- 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 */