Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / usb / usbip / usbip_event.c

diff --git a/kernel/drivers/usb/usbip/usbip_event.c b/kernel/drivers/usb/usbip/usbip_event.c
new file mode 100644 (file)
index 0000000..64933b9
--- /dev/null
+++ b/kernel/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);