From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 drivers/usb/usbip/usbip_event.c | 128 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 drivers/usb/usbip/usbip_event.c

(limited to 'drivers/usb/usbip/usbip_event.c')

diff --git a/drivers/usb/usbip/usbip_event.c b/drivers/usb/usbip/usbip_event.c
new file mode 100644
index 000000000..64933b993
--- /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);
-- 
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