]> git.saurik.com Git - apple/xnu.git/blobdiff - iokit/Kernel/IOCommandGate.cpp
xnu-2422.110.17.tar.gz
[apple/xnu.git] / iokit / Kernel / IOCommandGate.cpp
index 8f3f467131eca341de722272eced601c4d957c5c..9b19d70eefeb5e7dd63bfb88997f44401ed9c654 100644 (file)
@@ -1,14 +1,19 @@
 /*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2000, 2009-2010 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
+#include <libkern/OSDebug.h>
+
 #include <IOKit/IOCommandGate.h>
 #include <IOKit/IOWorkLoop.h>
 #include <IOKit/IOReturn.h>
 #include <IOKit/IOTimeStamp.h>
+#include <IOKit/IOKitDebug.h>
 
 #define super IOEventSource
 
 OSDefineMetaClassAndStructors(IOCommandGate, IOEventSource)
+#if __LP64__
 OSMetaClassDefineReservedUnused(IOCommandGate, 0);
+#else
+OSMetaClassDefineReservedUsed(IOCommandGate, 0);
+#endif
 OSMetaClassDefineReservedUnused(IOCommandGate, 1);
 OSMetaClassDefineReservedUnused(IOCommandGate, 2);
 OSMetaClassDefineReservedUnused(IOCommandGate, 3);
@@ -37,11 +49,33 @@ OSMetaClassDefineReservedUnused(IOCommandGate, 5);
 OSMetaClassDefineReservedUnused(IOCommandGate, 6);
 OSMetaClassDefineReservedUnused(IOCommandGate, 7);
 
-bool IOCommandGate::checkForWork() { return false; }
+#if IOKITSTATS
+
+#define IOStatisticsInitializeCounter() \
+do { \
+       IOStatistics::setCounterType(IOEventSource::reserved->counter, kIOStatisticsCommandGateCounter); \
+} while (0)
+
+#define IOStatisticsActionCall() \
+do { \
+       IOStatistics::countCommandGateActionCall(IOEventSource::reserved->counter); \
+} while (0)
+
+#else
+
+#define IOStatisticsInitializeCounter()
+#define IOStatisticsActionCall()
+
+#endif /* IOKITSTATS */
 
 bool IOCommandGate::init(OSObject *inOwner, Action inAction)
 {
-    return super::init(inOwner, (IOEventSource::Action) inAction);
+    bool res = super::init(inOwner, (IOEventSource::Action) inAction);
+    if (res) {
+        IOStatisticsInitializeCounter();
+    }
+
+    return res;
 }
 
 IOCommandGate *
@@ -57,73 +91,110 @@ IOCommandGate::commandGate(OSObject *inOwner, Action inAction)
     return me;
 }
 
-IOReturn IOCommandGate::runCommand(void *arg0, void *arg1,
-                                   void *arg2, void *arg3)
+/* virtual */ void IOCommandGate::disable()
 {
-    IOReturn res;
+    if (workLoop && !workLoop->inGate())
+       OSReportWithBacktrace("IOCommandGate::disable() called when not gated");
 
-    if (!enabled)
-        return kIOReturnNotPermitted;
+    super::disable();
+}
+
+/* virtual */ void IOCommandGate::enable()
+{
+    if (workLoop) {
+       closeGate();
+       super::enable();
+       wakeupGate(&enabled, /* oneThread */ false); // Unblock sleeping threads
+       openGate();
+    }
+}
 
-    if (!action)
-        return kIOReturnNoResources;
+/* virtual */ void IOCommandGate::free()
+{
+    setWorkLoop(0);
+    super::free();
+}
 
-    // closeGate is recursive so don't worry if we already hold the lock.
-    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-                       (unsigned int) action, (unsigned int) owner);
+/* virtual */ void IOCommandGate::setWorkLoop(IOWorkLoop *inWorkLoop)
+{
+    uintptr_t *sleepersP = (uintptr_t *) &reserved;
+    if (!inWorkLoop && workLoop) {             // tearing down
+       closeGate();
+       *sleepersP |= 1;
+       while (*sleepersP >> 1) {
+           thread_wakeup_with_result(&enabled, THREAD_INTERRUPTED);
+           sleepGate(sleepersP, THREAD_UNINT);
+       }
+       *sleepersP = 0;
+       openGate();
+    }
+    else
 
-    closeGate();
-    res = (*(Action) action)(owner, arg0, arg1, arg2, arg3);
-    openGate();
+    super::setWorkLoop(inWorkLoop);
+}
 
-    return res;
+IOReturn IOCommandGate::runCommand(void *arg0, void *arg1,
+                                   void *arg2, void *arg3)
+{
+    return runAction((Action) action, arg0, arg1, arg2, arg3);
+}
+
+IOReturn IOCommandGate::attemptCommand(void *arg0, void *arg1,
+                                       void *arg2, void *arg3)
+{
+    return attemptAction((Action) action, arg0, arg1, arg2, arg3);
 }
 
 IOReturn IOCommandGate::runAction(Action inAction,
                                   void *arg0, void *arg1,
                                   void *arg2, void *arg3)
 {
-    IOReturn res;
-
-    if (!enabled)
-        return kIOReturnNotPermitted;
-
     if (!inAction)
         return kIOReturnBadArgument;
 
-    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-                       (unsigned int) inAction, (unsigned int) owner);
-
-    // closeGate is recursive so don't worry if we already hold the lock.
+    // closeGate is recursive needn't worry if we already hold the lock.
     closeGate();
-    res = (*inAction)(owner, arg0, arg1, arg2, arg3);
-    openGate();
-
-    return res;
-}
 
-IOReturn IOCommandGate::attemptCommand(void *arg0, void *arg1,
-                                       void *arg2, void *arg3)
-{
+    // If the command gate is disabled and we aren't on the workloop thread
+    // itself then sleep until we get enabled.
     IOReturn res;
+    if (!workLoop->onThread()) {
+       while (!enabled) {
+           uintptr_t *sleepersP = (uintptr_t *) &reserved;
 
-    if (!enabled)
-        return kIOReturnNotPermitted;
+           *sleepersP += 2;
+           IOReturn res = sleepGate(&enabled, THREAD_ABORTSAFE);
+           *sleepersP -= 2;
 
-    if (!action)
-        return kIOReturnNoResources;
+           bool wakeupTearDown = (*sleepersP & 1);
+           if (res || wakeupTearDown) {
+               openGate();
 
-    // Try to hold the lock if can't get return immediately.
-    if (!tryCloseGate())
-        return kIOReturnCannotLock;
+                if (wakeupTearDown)
+                    commandWakeup(sleepersP);  // No further resources used
 
-    // closeGate is recursive so don't worry if we already hold the lock.
-    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-                       (unsigned int) action, (unsigned int) owner);
+               return kIOReturnAborted;
+           }
+       }
+    }
 
-    res = (*(Action) action)(owner, arg0, arg1, arg2, arg3);
+    bool trace = ( gIOKitTrace & kIOTraceCommandGates ) ? true : false;
+       
+       if (trace)
+               IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+                                        VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
+       
+    IOStatisticsActionCall();
+       
+    // Must be gated and on the work loop or enabled
+    res = (*inAction)(owner, arg0, arg1, arg2, arg3);
+       
+       if (trace)
+               IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+                                      VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
+    
     openGate();
-
+       
     return res;
 }
 
@@ -133,9 +204,6 @@ IOReturn IOCommandGate::attemptAction(Action inAction,
 {
     IOReturn res;
 
-    if (!enabled)
-        return kIOReturnNotPermitted;
-
     if (!inAction)
         return kIOReturnBadArgument;
 
@@ -143,10 +211,26 @@ IOReturn IOCommandGate::attemptAction(Action inAction,
     if (!tryCloseGate())
         return kIOReturnCannotLock;
 
-    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-                       (unsigned int) inAction, (unsigned int) owner);
+    // If the command gate is disabled then sleep until we get a wakeup
+    if (!workLoop->onThread() && !enabled)
+        res = kIOReturnNotPermitted;
+    else {
+               
+        bool trace = ( gIOKitTrace & kIOTraceCommandGates ) ? true : false;
+               
+        if (trace)
+            IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+                                    VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
+        
+        IOStatisticsActionCall();
+        
+        res = (*inAction)(owner, arg0, arg1, arg2, arg3);
+               
+        if (trace)
+            IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+                                  VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
+    }
 
-    res = (*inAction)(owner, arg0, arg1, arg2, arg3);
     openGate();
 
     return res;
@@ -160,6 +244,14 @@ IOReturn IOCommandGate::commandSleep(void *event, UInt32 interruptible)
     return sleepGate(event, interruptible);
 }
 
+IOReturn IOCommandGate::commandSleep(void *event, AbsoluteTime deadline, UInt32 interruptible)
+{
+    if (!workLoop->inGate())
+        return kIOReturnNotPermitted;
+
+    return sleepGate(event, deadline, interruptible);
+}
+
 void IOCommandGate::commandWakeup(void *event, bool oneThread)
 {
     wakeupGate(event, oneThread);