1 files changed, 128 insertions, 0 deletions

diff --git a/drivers/usb/usbip/usbip_event.c b/drivers/usb/usbip/usbip_event.c
new file mode 100644
index 000000000000..64933b993d7a
--- /dev/null
+++ b/drivers/usb/usbip/usbip_event.c
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This 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 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include <linux/kthread.h>
+#include <linux/export.h>
+
+#include "usbip_common.h"
+
+static int event_handler(struct usbip_device *ud)
+{
+        usbip_dbg_eh("enter\n");
+
+        /*
+         * Events are handled by only this thread.
+         */
+        while (usbip_event_happened(ud)) {
+                usbip_dbg_eh("pending event %lx\n", ud->event);
+
+                /*
+                 * NOTE: shutdown must come first.
+                 * Shutdown the device.
+                 */
+                if (ud->event & USBIP_EH_SHUTDOWN) {
+                        ud->eh_ops.shutdown(ud);
+                        ud->event &= ~USBIP_EH_SHUTDOWN;
+                }
+
+                /* Reset the device. */
+                if (ud->event & USBIP_EH_RESET) {
+                        ud->eh_ops.reset(ud);
+                        ud->event &= ~USBIP_EH_RESET;
+                }
+
+                /* Mark the device as unusable. */
+                if (ud->event & USBIP_EH_UNUSABLE) {
+                        ud->eh_ops.unusable(ud);
+                        ud->event &= ~USBIP_EH_UNUSABLE;
+                }
+
+                /* Stop the error handler. */
+                if (ud->event & USBIP_EH_BYE)
+                        return -1;
+        }
+
+        return 0;
+}
+
+static int event_handler_loop(void *data)
+{
+        struct usbip_device *ud = data;
+
+        while (!kthread_should_stop()) {
+                wait_event_interruptible(ud->eh_waitq,
+                                         usbip_event_happened(ud) ||
+                                         kthread_should_stop());
+                usbip_dbg_eh("wakeup\n");
+
+                if (event_handler(ud) < 0)
+                        break;
+        }
+
+        return 0;
+}
+
+int usbip_start_eh(struct usbip_device *ud)
+{
+        init_waitqueue_head(&ud->eh_waitq);
+        ud->event = 0;
+
+        ud->eh = kthread_run(event_handler_loop, ud, "usbip_eh");
+        if (IS_ERR(ud->eh)) {
+                pr_warn("Unable to start control thread\n");
+                return PTR_ERR(ud->eh);
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(usbip_start_eh);
+
+void usbip_stop_eh(struct usbip_device *ud)
+{
+        if (ud->eh == current)
+                return; /* do not wait for myself */
+
+        kthread_stop(ud->eh);
+        usbip_dbg_eh("usbip_eh has finished\n");
+}
+EXPORT_SYMBOL_GPL(usbip_stop_eh);
+
+void usbip_event_add(struct usbip_device *ud, unsigned long event)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&ud->lock, flags);
+        ud->event |= event;
+        wake_up(&ud->eh_waitq);
+        spin_unlock_irqrestore(&ud->lock, flags);
+}
+EXPORT_SYMBOL_GPL(usbip_event_add);
+
+int usbip_event_happened(struct usbip_device *ud)
+{
+        int happened = 0;
+
+        spin_lock(&ud->lock);
+        if (ud->event != 0)
+                happened = 1;
+        spin_unlock(&ud->lock);
+
+        return happened;
+}
+EXPORT_SYMBOL_GPL(usbip_event_happened);