usbip: vudc: Add vudc_transfer
authorIgor Kotrasinski <i.kotrasinsk@samsung.com>
Tue, 8 Mar 2016 20:49:00 +0000 (21:49 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 26 Apr 2016 22:19:50 +0000 (15:19 -0700)
This file contains a function that simulates USB traffic, based on
the one in dummy_hcd. Is also handles udc-directed control
requests, and contains functions for setting up and controlling
a timer for the emulation.

This commit is a result of cooperation between Samsung R&D Institute
Poland and Open Operating Systems Student Society at University
of Warsaw (O2S3@UW) consisting of:

    Igor Kotrasinski <ikotrasinsk@gmail.com>
    Karol Kosik <karo9@interia.eu>
    Ewelina Kosmider <3w3lfin@gmail.com>
    Dawid Lazarczyk <lazarczyk.dawid@gmail.com>
    Piotr Szulc <ps347277@students.mimuw.edu.pl>

Tutor and project owner:
    Krzysztof Opasiak <k.opasiak@samsung.com>

Signed-off-by: Igor Kotrasinski <i.kotrasinsk@samsung.com>
Signed-off-by: Karol Kosik <karo9@interia.eu>
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/usbip/vudc_transfer.c [new file with mode: 0644]

diff --git a/drivers/usb/usbip/vudc_transfer.c b/drivers/usb/usbip/vudc_transfer.c
new file mode 100644 (file)
index 0000000..5ccde52
--- /dev/null
@@ -0,0 +1,506 @@
+/*
+ * Copyright (C) 2015 Karol Kosik <karo9@interia.eu>
+ * Copyright (C) 2015-2016 Samsung Electronics
+ *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
+ *
+ * Based on dummy_hcd.c, which is:
+ * Copyright (C) 2003 David Brownell
+ * Copyright (C) 2003-2005 Alan Stern
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/>.
+ */
+
+#include <linux/usb.h>
+#include <linux/timer.h>
+#include <linux/usb/ch9.h>
+
+#include "vudc.h"
+
+#define DEV_REQUEST    (USB_TYPE_STANDARD | USB_RECIP_DEVICE)
+#define DEV_INREQUEST  (DEV_REQUEST | USB_DIR_IN)
+#define INTF_REQUEST   (USB_TYPE_STANDARD | USB_RECIP_INTERFACE)
+#define INTF_INREQUEST (INTF_REQUEST | USB_DIR_IN)
+#define EP_REQUEST     (USB_TYPE_STANDARD | USB_RECIP_ENDPOINT)
+#define EP_INREQUEST   (EP_REQUEST | USB_DIR_IN)
+
+static int get_frame_limit(enum usb_device_speed speed)
+{
+       switch (speed) {
+       case USB_SPEED_LOW:
+               return 8 /*bytes*/ * 12 /*packets*/;
+       case USB_SPEED_FULL:
+               return 64 /*bytes*/ * 19 /*packets*/;
+       case USB_SPEED_HIGH:
+               return 512 /*bytes*/ * 13 /*packets*/ * 8 /*uframes*/;
+       case USB_SPEED_SUPER:
+               /* Bus speed is 500000 bytes/ms, so use a little less */
+               return 490000;
+       default:
+               /* error */
+               return -1;
+       }
+
+}
+
+/*
+ * handle_control_request() - handles all control transfers
+ * @udc: pointer to vudc
+ * @urb: the urb request to handle
+ * @setup: pointer to the setup data for a USB device control
+ *      request
+ * @status: pointer to request handling status
+ *
+ * Return 0 - if the request was handled
+ *       1 - if the request wasn't handles
+ *       error code on error
+ *
+ * Adapted from drivers/usb/gadget/udc/dummy_hcd.c
+ */
+static int handle_control_request(struct vudc *udc, struct urb *urb,
+                                 struct usb_ctrlrequest *setup,
+                                 int *status)
+{
+       struct vep      *ep2;
+       int             ret_val = 1;
+       unsigned        w_index;
+       unsigned        w_value;
+
+       w_index = le16_to_cpu(setup->wIndex);
+       w_value = le16_to_cpu(setup->wValue);
+       switch (setup->bRequest) {
+       case USB_REQ_SET_ADDRESS:
+               if (setup->bRequestType != DEV_REQUEST)
+                       break;
+               udc->address = w_value;
+               ret_val = 0;
+               *status = 0;
+               break;
+       case USB_REQ_SET_FEATURE:
+               if (setup->bRequestType == DEV_REQUEST) {
+                       ret_val = 0;
+                       switch (w_value) {
+                       case USB_DEVICE_REMOTE_WAKEUP:
+                               break;
+                       case USB_DEVICE_B_HNP_ENABLE:
+                               udc->gadget.b_hnp_enable = 1;
+                               break;
+                       case USB_DEVICE_A_HNP_SUPPORT:
+                               udc->gadget.a_hnp_support = 1;
+                               break;
+                       case USB_DEVICE_A_ALT_HNP_SUPPORT:
+                               udc->gadget.a_alt_hnp_support = 1;
+                               break;
+                       default:
+                               ret_val = -EOPNOTSUPP;
+                       }
+                       if (ret_val == 0) {
+                               udc->devstatus |= (1 << w_value);
+                               *status = 0;
+                       }
+               } else if (setup->bRequestType == EP_REQUEST) {
+                       /* endpoint halt */
+                       ep2 = find_endpoint(udc, w_index);
+                       if (!ep2 || ep2->ep.name == udc->ep[0].ep.name) {
+                               ret_val = -EOPNOTSUPP;
+                               break;
+                       }
+                       ep2->halted = 1;
+                       ret_val = 0;
+                       *status = 0;
+               }
+               break;
+       case USB_REQ_CLEAR_FEATURE:
+               if (setup->bRequestType == DEV_REQUEST) {
+                       ret_val = 0;
+                       switch (w_value) {
+                       case USB_DEVICE_REMOTE_WAKEUP:
+                               w_value = USB_DEVICE_REMOTE_WAKEUP;
+                               break;
+
+                       case USB_DEVICE_U1_ENABLE:
+                       case USB_DEVICE_U2_ENABLE:
+                       case USB_DEVICE_LTM_ENABLE:
+                               ret_val = -EOPNOTSUPP;
+                               break;
+                       default:
+                               ret_val = -EOPNOTSUPP;
+                               break;
+                       }
+                       if (ret_val == 0) {
+                               udc->devstatus &= ~(1 << w_value);
+                               *status = 0;
+                       }
+               } else if (setup->bRequestType == EP_REQUEST) {
+                       /* endpoint halt */
+                       ep2 = find_endpoint(udc, w_index);
+                       if (!ep2) {
+                               ret_val = -EOPNOTSUPP;
+                               break;
+                       }
+                       if (!ep2->wedged)
+                               ep2->halted = 0;
+                       ret_val = 0;
+                       *status = 0;
+               }
+               break;
+       case USB_REQ_GET_STATUS:
+               if (setup->bRequestType == DEV_INREQUEST
+                               || setup->bRequestType == INTF_INREQUEST
+                               || setup->bRequestType == EP_INREQUEST) {
+                       char *buf;
+                       /*
+                        * device: remote wakeup, selfpowered
+                        * interface: nothing
+                        * endpoint: halt
+                        */
+                       buf = (char *)urb->transfer_buffer;
+                       if (urb->transfer_buffer_length > 0) {
+                               if (setup->bRequestType == EP_INREQUEST) {
+                                       ep2 = find_endpoint(udc, w_index);
+                                       if (!ep2) {
+                                               ret_val = -EOPNOTSUPP;
+                                               break;
+                                       }
+                                       buf[0] = ep2->halted;
+                               } else if (setup->bRequestType ==
+                                          DEV_INREQUEST) {
+                                       buf[0] = (u8)udc->devstatus;
+                               } else
+                                       buf[0] = 0;
+                       }
+                       if (urb->transfer_buffer_length > 1)
+                               buf[1] = 0;
+                       urb->actual_length = min_t(u32, 2,
+                               urb->transfer_buffer_length);
+                       ret_val = 0;
+                       *status = 0;
+               }
+               break;
+       }
+       return ret_val;
+}
+
+/* Adapted from dummy_hcd.c ; caller must hold lock */
+static int transfer(struct vudc *udc,
+               struct urb *urb, struct vep *ep, int limit)
+{
+       struct vrequest *req;
+       int sent = 0;
+top:
+       /* if there's no request queued, the device is NAKing; return */
+       list_for_each_entry(req, &ep->req_queue, req_entry) {
+               unsigned        host_len, dev_len, len;
+               void            *ubuf_pos, *rbuf_pos;
+               int             is_short, to_host;
+               int             rescan = 0;
+
+               /*
+                * 1..N packets of ep->ep.maxpacket each ... the last one
+                * may be short (including zero length).
+                *
+                * writer can send a zlp explicitly (length 0) or implicitly
+                * (length mod maxpacket zero, and 'zero' flag); they always
+                * terminate reads.
+                */
+               host_len = urb->transfer_buffer_length - urb->actual_length;
+               dev_len = req->req.length - req->req.actual;
+               len = min(host_len, dev_len);
+
+               to_host = usb_pipein(urb->pipe);
+               if (unlikely(len == 0))
+                       is_short = 1;
+               else {
+                       /* send multiple of maxpacket first, then remainder */
+                       if (len >= ep->ep.maxpacket) {
+                               is_short = 0;
+                               if (len % ep->ep.maxpacket > 0)
+                                       rescan = 1;
+                               len -= len % ep->ep.maxpacket;
+                       } else {
+                               is_short = 1;
+                       }
+
+                       ubuf_pos = urb->transfer_buffer + urb->actual_length;
+                       rbuf_pos = req->req.buf + req->req.actual;
+
+                       if (urb->pipe & USB_DIR_IN)
+                               memcpy(ubuf_pos, rbuf_pos, len);
+                       else
+                               memcpy(rbuf_pos, ubuf_pos, len);
+
+                       urb->actual_length += len;
+                       req->req.actual += len;
+                       sent += len;
+               }
+
+               /*
+                * short packets terminate, maybe with overflow/underflow.
+                * it's only really an error to write too much.
+                *
+                * partially filling a buffer optionally blocks queue advances
+                * (so completion handlers can clean up the queue) but we don't
+                * need to emulate such data-in-flight.
+                */
+               if (is_short) {
+                       if (host_len == dev_len) {
+                               req->req.status = 0;
+                               urb->status = 0;
+                       } else if (to_host) {
+                               req->req.status = 0;
+                               if (dev_len > host_len)
+                                       urb->status = -EOVERFLOW;
+                               else
+                                       urb->status = 0;
+                       } else {
+                               urb->status = 0;
+                               if (host_len > dev_len)
+                                       req->req.status = -EOVERFLOW;
+                               else
+                                       req->req.status = 0;
+                       }
+
+               /* many requests terminate without a short packet */
+               /* also check if we need to send zlp */
+               } else {
+                       if (req->req.length == req->req.actual) {
+                               if (req->req.zero && to_host)
+                                       rescan = 1;
+                               else
+                                       req->req.status = 0;
+                       }
+                       if (urb->transfer_buffer_length == urb->actual_length) {
+                               if (urb->transfer_flags & URB_ZERO_PACKET &&
+                                   !to_host)
+                                       rescan = 1;
+                               else
+                                       urb->status = 0;
+                       }
+               }
+
+               /* device side completion --> continuable */
+               if (req->req.status != -EINPROGRESS) {
+
+                       list_del_init(&req->req_entry);
+                       spin_unlock(&udc->lock);
+                       usb_gadget_giveback_request(&ep->ep, &req->req);
+                       spin_lock(&udc->lock);
+
+                       /* requests might have been unlinked... */
+                       rescan = 1;
+               }
+
+               /* host side completion --> terminate */
+               if (urb->status != -EINPROGRESS)
+                       break;
+
+               /* rescan to continue with any other queued i/o */
+               if (rescan)
+                       goto top;
+       }
+       return sent;
+}
+
+static void v_timer(unsigned long _vudc)
+{
+       struct vudc *udc = (struct vudc *) _vudc;
+       struct transfer_timer *timer = &udc->tr_timer;
+       struct urbp *urb_p, *tmp;
+       unsigned long flags;
+       struct usb_ep *_ep;
+       struct vep *ep;
+       int ret = 0;
+       int total, limit;
+
+       spin_lock_irqsave(&udc->lock, flags);
+
+       total = get_frame_limit(udc->gadget.speed);
+       if (total < 0) {        /* unknown speed, or not set yet */
+               timer->state = VUDC_TR_IDLE;
+               spin_unlock_irqrestore(&udc->lock, flags);
+               return;
+       }
+       /* is it next frame now? */
+       if (time_after(jiffies, timer->frame_start + msecs_to_jiffies(1))) {
+               timer->frame_limit = total;
+               /* FIXME: how to make it accurate? */
+               timer->frame_start = jiffies;
+       } else {
+               total = timer->frame_limit;
+       }
+
+       list_for_each_entry(_ep, &udc->gadget.ep_list, ep_list) {
+               ep = to_vep(_ep);
+               ep->already_seen = 0;
+       }
+
+restart:
+       list_for_each_entry_safe(urb_p, tmp, &udc->urb_queue, urb_entry) {
+               struct urb *urb = urb_p->urb;
+
+               ep = urb_p->ep;
+               if (urb->unlinked)
+                       goto return_urb;
+               if (timer->state != VUDC_TR_RUNNING)
+                       continue;
+
+               if (!ep) {
+                       urb->status = -EPROTO;
+                       goto return_urb;
+               }
+
+               /* Used up bandwidth? */
+               if (total <= 0 && ep->type == USB_ENDPOINT_XFER_BULK)
+                       continue;
+
+               if (ep->already_seen)
+                       continue;
+               ep->already_seen = 1;
+               if (ep == &udc->ep[0] && urb_p->new) {
+                       ep->setup_stage = 1;
+                       urb_p->new = 0;
+               }
+               if (ep->halted && !ep->setup_stage) {
+                       urb->status = -EPIPE;
+                       goto return_urb;
+               }
+
+               if (ep == &udc->ep[0] && ep->setup_stage) {
+                       /* TODO - flush any stale requests */
+                       ep->setup_stage = 0;
+                       ep->halted = 0;
+
+                       ret = handle_control_request(udc, urb,
+                               (struct usb_ctrlrequest *) urb->setup_packet,
+                               (&urb->status));
+                       if (ret > 0) {
+                               spin_unlock(&udc->lock);
+                               ret = udc->driver->setup(&udc->gadget,
+                                       (struct usb_ctrlrequest *)
+                                       urb->setup_packet);
+                               spin_lock(&udc->lock);
+                       }
+                       if (ret >= 0) {
+                               /* no delays (max 64kb data stage) */
+                               limit = 64 * 1024;
+                               goto treat_control_like_bulk;
+                       } else {
+                               urb->status = -EPIPE;
+                               urb->actual_length = 0;
+                               goto return_urb;
+                       }
+               }
+
+               limit = total;
+               switch (ep->type) {
+               case USB_ENDPOINT_XFER_ISOC:
+                       /* TODO: support */
+                       urb->status = -EXDEV;
+                       break;
+
+               case USB_ENDPOINT_XFER_INT:
+                       /*
+                        * TODO: figure out bandwidth guarantees
+                        * for now, give unlimited bandwidth
+                        */
+                       limit += urb->transfer_buffer_length;
+                       /* fallthrough */
+               default:
+treat_control_like_bulk:
+                       total -= transfer(udc, urb, ep, limit);
+               }
+               if (urb->status == -EINPROGRESS)
+                       continue;
+
+return_urb:
+               if (ep)
+                       ep->already_seen = ep->setup_stage = 0;
+
+               spin_lock(&udc->lock_tx);
+               list_del(&urb_p->urb_entry);
+               if (!urb->unlinked) {
+                       v_enqueue_ret_submit(udc, urb_p);
+               } else {
+                       v_enqueue_ret_unlink(udc, urb_p->seqnum,
+                                            urb->unlinked);
+                       free_urbp_and_urb(urb_p);
+               }
+               wake_up(&udc->tx_waitq);
+               spin_unlock(&udc->lock_tx);
+
+               goto restart;
+       }
+
+       /* TODO - also wait on empty usb_request queues? */
+       if (list_empty(&udc->urb_queue))
+               timer->state = VUDC_TR_IDLE;
+       else
+               mod_timer(&timer->timer,
+                         timer->frame_start + msecs_to_jiffies(1));
+
+       spin_unlock_irqrestore(&udc->lock, flags);
+}
+
+/* All timer functions are run with udc->lock held */
+
+void v_init_timer(struct vudc *udc)
+{
+       struct transfer_timer *t = &udc->tr_timer;
+
+       setup_timer(&t->timer, v_timer, (unsigned long) udc);
+       t->state = VUDC_TR_STOPPED;
+}
+
+void v_start_timer(struct vudc *udc)
+{
+       struct transfer_timer *t = &udc->tr_timer;
+
+       dev_dbg(&udc->pdev->dev, "timer start");
+       switch (t->state) {
+       case VUDC_TR_RUNNING:
+               return;
+       case VUDC_TR_IDLE:
+               return v_kick_timer(udc, jiffies);
+       case VUDC_TR_STOPPED:
+               t->state = VUDC_TR_IDLE;
+               t->frame_start = jiffies;
+               t->frame_limit = get_frame_limit(udc->gadget.speed);
+               return v_kick_timer(udc, jiffies);
+       }
+}
+
+void v_kick_timer(struct vudc *udc, unsigned long time)
+{
+       struct transfer_timer *t = &udc->tr_timer;
+
+       dev_dbg(&udc->pdev->dev, "timer kick");
+       switch (t->state) {
+       case VUDC_TR_RUNNING:
+               return;
+       case VUDC_TR_IDLE:
+               t->state = VUDC_TR_RUNNING;
+               /* fallthrough */
+       case VUDC_TR_STOPPED:
+               /* we may want to kick timer to unqueue urbs */
+               mod_timer(&t->timer, time);
+       }
+}
+
+void v_stop_timer(struct vudc *udc)
+{
+       struct transfer_timer *t = &udc->tr_timer;
+
+       /* timer itself will take care of stopping */
+       dev_dbg(&udc->pdev->dev, "timer stop");
+       t->state = VUDC_TR_STOPPED;
+}
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