xnu-792.17.14.tar.gz

[apple/xnu.git] / iokit / Kernel / IOMultiMemoryDescriptor.cpp

diff --git a/iokit/Kernel/IOMultiMemoryDescriptor.cpp b/iokit/Kernel/IOMultiMemoryDescriptor.cpp
index 174fb7d91f033cfac03433b12e8816b63a1e5aeb..224a6bdba35e307916ff2415cc0627cc01ec5e90 100644 (file)
--- a/iokit/Kernel/IOMultiMemoryDescriptor.cpp
+++ b/iokit/Kernel/IOMultiMemoryDescriptor.cpp
@@ -1,23 +1,29 @@
 /*
  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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. 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.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * 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 <IOKit/IOLib.h>
@@ -87,7 +93,7 @@ IOMultiMemoryDescriptor * IOMultiMemoryDescriptor::withDescriptors(
                                   IOMemoryDescriptor ** descriptors,
                                   UInt32                withCount,
                                   IODirection           withDirection,
-                                  bool                  asReference = false )
+                                  bool                  asReference )
 {
     //
     // Create a new IOMultiMemoryDescriptor.  The "buffer" is made up of several
@@ -118,7 +124,7 @@ bool IOMultiMemoryDescriptor::initWithDescriptors(
                                   IOMemoryDescriptor ** descriptors,
                                   UInt32                withCount,
                                   IODirection           withDirection,
-                                  bool                  asReference = false )
+                                  bool                  asReference )
 {
     //
     // Initialize an IOMultiMemoryDescriptor. The "buffer" is made up of several
@@ -131,10 +137,19 @@ bool IOMultiMemoryDescriptor::initWithDescriptors(
     assert(descriptors);
     assert(withCount);
 
-    // Ask our superclass' opinion.
-
-    if ( super::init() == false )  return false;
+    // Release existing descriptors, if any
+    if ( _descriptors )
+    {
+        for ( unsigned index = 0; index < _descriptorsCount; index++ ) 
+            _descriptors[index]->release();
 
+        if ( _descriptorsIsAllocated )
+            IODelete(_descriptors, IOMemoryDescriptor *, _descriptorsCount);
+    } else {
+        // Ask our superclass' opinion.
+        if ( super::init() == false )  return false;
+    }
+    
     // Initialize our minimal state.
 
     _descriptors            = 0;
@@ -289,6 +304,34 @@ IOPhysicalAddress IOMultiMemoryDescriptor::getPhysicalSegment(
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+IOPhysicalAddress IOMultiMemoryDescriptor::getSourceSegment(
+                                                       IOByteCount   offset,
+                                                       IOByteCount * length )
+{
+    //
+    // This method returns the physical address of the byte at the given offset
+    // into the memory,  and optionally the length of the physically contiguous
+    // segment from that offset.
+    //
+
+    assert(offset <= _length);
+
+    for ( unsigned index = 0; index < _descriptorsCount; index++ ) 
+    {
+        if ( offset < _descriptors[index]->getLength() )
+        {
+            return _descriptors[index]->getSourceSegment(offset, length);
+        }
+        offset -= _descriptors[index]->getLength();
+    }
+
+    if ( length )  *length = 0;
+
+    return 0;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 void * IOMultiMemoryDescriptor::getVirtualSegment( IOByteCount   /* offset */ ,
                                                    IOByteCount * /* length */ )
 {