diff options
author | Hans de Goede <hdegoede@redhat.com> | 2013-10-09 17:19:31 +0200 |
---|---|---|
committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2014-03-04 15:38:05 -0800 |
commit | bcf7f6e39335af4f03da8c26a98185fd49754fcc (patch) | |
tree | 61a8b40af9264409c66ced8ac324e3f3274f00ff /drivers/usb/core/devio.c | |
parent | 2fec32b06e374642802f7fb4f5350317cd14732b (diff) | |
download | linux-bcf7f6e39335af4f03da8c26a98185fd49754fcc.tar.bz2 |
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 <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb/core/devio.c')
-rw-r--r-- | drivers/usb/core/devio.c | 118 |
1 files changed, 118 insertions, 0 deletions
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) |