From 376fdba15bcf4b106ba7d62ee350baf21099cfbf Mon Sep 17 00:00:00 2001
From: popcornmix <popcornmix@gmail.com>
Date: Mon, 12 May 2014 15:12:02 +0100
Subject: [PATCH 07/54] vchiq: Avoid high load when blocked and unkillable

---
 .../interface/vchiq_arm/vchiq_2835_arm.c           |  1 +
 .../vc04_services/interface/vchiq_arm/vchiq_arm.c  |  1 +
 .../interface/vchiq_arm/vchiq_connected.c          |  1 +
 .../vc04_services/interface/vchiq_arm/vchiq_core.c |  1 +
 .../interface/vchiq_arm/vchiq_kern_lib.c           |  1 +
 .../interface/vchiq_arm/vchiq_killable.h           | 69 ++++++++++++++++++++++
 .../vc04_services/interface/vchiq_arm/vchiq_util.c |  1 +
 7 files changed, 75 insertions(+)
 create mode 100644 drivers/misc/vc04_services/interface/vchiq_arm/vchiq_killable.h

--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
@@ -56,6 +56,7 @@
 #include "vchiq_arm.h"
 #include "vchiq_2835.h"
 #include "vchiq_connected.h"
+#include "vchiq_killable.h"
 
 #define MAX_FRAGMENTS (VCHIQ_NUM_CURRENT_BULKS * 2)
 
--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_arm.c
@@ -49,6 +49,7 @@
 #include "vchiq_core.h"
 #include "vchiq_ioctl.h"
 #include "vchiq_arm.h"
+#include "vchiq_killable.h"
 
 #define DEVICE_NAME "vchiq"
 
--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_connected.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_connected.c
@@ -33,6 +33,7 @@
 
 #include "vchiq_connected.h"
 #include "vchiq_core.h"
+#include "vchiq_killable.h"
 #include <linux/module.h>
 #include <linux/mutex.h>
 
--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_core.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_core.c
@@ -32,6 +32,7 @@
  */
 
 #include "vchiq_core.h"
+#include "vchiq_killable.h"
 
 #define VCHIQ_SLOT_HANDLER_STACK 8192
 
--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_kern_lib.c
@@ -39,6 +39,7 @@
 
 #include "vchiq_core.h"
 #include "vchiq_arm.h"
+#include "vchiq_killable.h"
 
 /* ---- Public Variables ------------------------------------------------- */
 
--- /dev/null
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_killable.h
@@ -0,0 +1,69 @@
+/**
+ * Copyright (c) 2010-2012 Broadcom. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the above-listed copyright holders may not be used
+ *    to endorse or promote products derived from this software without
+ *    specific prior written permission.
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2, as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef VCHIQ_KILLABLE_H
+#define VCHIQ_KILLABLE_H
+
+#include <linux/mutex.h>
+#include <linux/semaphore.h>
+
+#define SHUTDOWN_SIGS   (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT))
+
+static inline int __must_check down_interruptible_killable(struct semaphore *sem)
+{
+	/* Allow interception of killable signals only. We don't want to be interrupted by harmless signals like SIGALRM */
+	int ret;
+	sigset_t blocked, oldset;
+	siginitsetinv(&blocked, SHUTDOWN_SIGS);
+	sigprocmask(SIG_SETMASK, &blocked, &oldset);
+	ret = down_interruptible(sem);
+	sigprocmask(SIG_SETMASK, &oldset, NULL);
+	return ret;
+}
+#define down_interruptible down_interruptible_killable
+
+
+static inline int __must_check mutex_lock_interruptible_killable(struct mutex *lock)
+{
+	/* Allow interception of killable signals only. We don't want to be interrupted by harmless signals like SIGALRM */
+	int ret;
+	sigset_t blocked, oldset;
+	siginitsetinv(&blocked, SHUTDOWN_SIGS);
+	sigprocmask(SIG_SETMASK, &blocked, &oldset);
+	ret = mutex_lock_interruptible(lock);
+	sigprocmask(SIG_SETMASK, &oldset, NULL);
+	return ret;
+}
+#define mutex_lock_interruptible mutex_lock_interruptible_killable
+
+#endif
--- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_util.c
+++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_util.c
@@ -32,6 +32,7 @@
  */
 
 #include "vchiq_util.h"
+#include "vchiq_killable.h"
 
 static inline int is_pow2(int i)
 {
