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--- xnu/xnu-4570.20.62/iokit/Kernel/IODataQueue.cpp
+++ xnu/xnu-792/iokit/Kernel/IODataQueue.cpp
@@ -1,47 +1,29 @@
/*
* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * @APPLE_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. 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.
+ * 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.
*
- * 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
+ * This 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
- * limitations under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ * @APPLE_LICENSE_HEADER_END@
*/
-#define DISABLE_DATAQUEUE_WARNING
-
#include <IOKit/IODataQueue.h>
-
-#undef DISABLE_DATAQUEUE_WARNING
-
#include <IOKit/IODataQueueShared.h>
#include <IOKit/IOLib.h>
#include <IOKit/IOMemoryDescriptor.h>
-#include <libkern/OSAtomic.h>
-
-struct IODataQueueInternal
-{
- mach_msg_header_t msg;
- UInt32 queueSize;
-};
#ifdef enqueue
#undef enqueue
@@ -85,68 +67,31 @@
Boolean IODataQueue::initWithCapacity(UInt32 size)
{
- vm_size_t allocSize = 0;
-
if (!super::init()) {
return false;
}
- if (size > UINT32_MAX - DATA_QUEUE_MEMORY_HEADER_SIZE) {
- return false;
- }
-
- allocSize = round_page(size + DATA_QUEUE_MEMORY_HEADER_SIZE);
-
- if (allocSize < size) {
- return false;
- }
-
- assert(!notifyMsg);
- notifyMsg = IONew(IODataQueueInternal, 1);
- if (!notifyMsg) {
- return false;
- }
- bzero(notifyMsg, sizeof(IODataQueueInternal));
- ((IODataQueueInternal *)notifyMsg)->queueSize = size;
-
- dataQueue = (IODataQueueMemory *)IOMallocAligned(allocSize, PAGE_SIZE);
+ dataQueue = (IODataQueueMemory *)IOMallocAligned(round_page_32(size + DATA_QUEUE_MEMORY_HEADER_SIZE), PAGE_SIZE);
if (dataQueue == 0) {
return false;
}
- bzero(dataQueue, allocSize);
-
- dataQueue->queueSize = size;
-// dataQueue->head = 0;
-// dataQueue->tail = 0;
+
+ dataQueue->queueSize = size;
+ dataQueue->head = 0;
+ dataQueue->tail = 0;
return true;
}
Boolean IODataQueue::initWithEntries(UInt32 numEntries, UInt32 entrySize)
{
- // Checking overflow for (numEntries + 1)*(entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE):
- // check (entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE)
- if ((entrySize > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) ||
- // check (numEntries + 1)
- (numEntries > UINT32_MAX-1) ||
- // check (numEntries + 1)*(entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE)
- (entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE > UINT32_MAX/(numEntries+1))) {
- return false;
- }
-
return (initWithCapacity((numEntries + 1) * (DATA_QUEUE_ENTRY_HEADER_SIZE + entrySize)));
}
void IODataQueue::free()
{
- if (notifyMsg) {
- if (dataQueue) {
- IOFreeAligned(dataQueue, round_page(((IODataQueueInternal *)notifyMsg)->queueSize + DATA_QUEUE_MEMORY_HEADER_SIZE));
- dataQueue = NULL;
- }
-
- IODelete(notifyMsg, IODataQueueInternal, 1);
- notifyMsg = NULL;
+ if (dataQueue) {
+ IOFreeAligned(dataQueue, round_page_32(dataQueue->queueSize + DATA_QUEUE_MEMORY_HEADER_SIZE));
}
super::free();
@@ -156,33 +101,15 @@
Boolean IODataQueue::enqueue(void * data, UInt32 dataSize)
{
- UInt32 head;
- UInt32 tail;
- UInt32 newTail;
+ const UInt32 head = dataQueue->head; // volatile
+ const UInt32 tail = dataQueue->tail;
const UInt32 entrySize = dataSize + DATA_QUEUE_ENTRY_HEADER_SIZE;
- UInt32 queueSize;
IODataQueueEntry * entry;
-
- // Check for overflow of entrySize
- if (dataSize > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) {
- return false;
- }
-
- // Force a single read of head and tail
- head = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED);
- tail = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->tail, __ATOMIC_RELAXED);
-
- // Check for underflow of (dataQueue->queueSize - tail)
- queueSize = ((IODataQueueInternal *) notifyMsg)->queueSize;
- if ((queueSize < tail) || (queueSize < head)) {
- return false;
- }
if ( tail >= head )
{
// Is there enough room at the end for the entry?
- if ((entrySize <= UINT32_MAX - tail) &&
- ((tail + entrySize) <= queueSize) )
+ if ( (tail + entrySize) <= dataQueue->queueSize )
{
entry = (IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail);
@@ -193,9 +120,9 @@
// exactly matches the available space at the end of the queue.
// The tail can range from 0 to dataQueue->queueSize inclusive.
- newTail = tail + entrySize;
- }
- else if ( head > entrySize ) // Is there enough room at the beginning?
+ dataQueue->tail += entrySize;
+ }
+ else if ( head > entrySize ) // Is there enough room at the beginning?
{
// Wrap around to the beginning, but do not allow the tail to catch
// up to the head.
@@ -206,17 +133,17 @@
// doing this. The user client checks for this and will look for the size
// at the beginning if there isn't room for it at the end.
- if ( ( queueSize - tail ) >= DATA_QUEUE_ENTRY_HEADER_SIZE )
+ if ( ( dataQueue->queueSize - tail ) >= DATA_QUEUE_ENTRY_HEADER_SIZE )
{
((IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail))->size = dataSize;
}
memcpy(&dataQueue->queue->data, data, dataSize);
- newTail = entrySize;
+ dataQueue->tail = entrySize;
}
else
{
- return false; // queue is full
+ return false; // queue is full
}
}
else
@@ -230,21 +157,18 @@
entry->size = dataSize;
memcpy(&entry->data, data, dataSize);
- newTail = tail + entrySize;
+ dataQueue->tail += entrySize;
}
else
{
- return false; // queue is full
- }
- }
-
- // Store tail with a release memory barrier
- __c11_atomic_store((_Atomic UInt32 *)&dataQueue->tail, newTail, __ATOMIC_RELEASE);
+ return false; // queue is full
+ }
+ }
// Send notification (via mach message) that data is available.
if ( ( head == tail ) /* queue was empty prior to enqueue() */
- || ( tail == __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED) ) ) /* queue was emptied during enqueue() */
+ || ( dataQueue->head == tail ) ) /* queue was emptied during enqueue() */
{
sendDataAvailableNotification();
}
@@ -254,27 +178,35 @@
void IODataQueue::setNotificationPort(mach_port_t port)
{
- mach_msg_header_t * msgh;
-
- msgh = &((IODataQueueInternal *) notifyMsg)->msg;
- bzero(msgh, sizeof(mach_msg_header_t));
- msgh->msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, 0);
- msgh->msgh_size = sizeof(mach_msg_header_t);
- msgh->msgh_remote_port = port;
+ static struct _notifyMsg init_msg = { {
+ MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, 0),
+ sizeof (struct _notifyMsg),
+ MACH_PORT_NULL,
+ MACH_PORT_NULL,
+ 0,
+ 0
+ } };
+
+ if (notifyMsg == 0) {
+ notifyMsg = IOMalloc(sizeof(struct _notifyMsg));
+ }
+
+ *((struct _notifyMsg *)notifyMsg) = init_msg;
+
+ ((struct _notifyMsg *)notifyMsg)->h.msgh_remote_port = port;
}
void IODataQueue::sendDataAvailableNotification()
{
- kern_return_t kr;
- mach_msg_header_t * msgh;
-
- msgh = &((IODataQueueInternal *) notifyMsg)->msg;
- if (msgh->msgh_remote_port) {
- kr = mach_msg_send_from_kernel_with_options(msgh, msgh->msgh_size, MACH_SEND_TIMEOUT, MACH_MSG_TIMEOUT_NONE);
+ kern_return_t kr;
+ mach_msg_header_t * msgh;
+
+ msgh = (mach_msg_header_t *)notifyMsg;
+ if (msgh) {
+ kr = mach_msg_send_from_kernel(msgh, msgh->msgh_size);
switch(kr) {
- case MACH_SEND_TIMED_OUT: // Notification already sent
+ case MACH_SEND_TIMED_OUT: // Notification already sent
case MACH_MSG_SUCCESS:
- case MACH_SEND_NO_BUFFER:
break;
default:
IOLog("%s: dataAvailableNotification failed - msg_send returned: %d\n", /*getName()*/"IODataQueue", kr);
@@ -286,14 +218,11 @@
IOMemoryDescriptor *IODataQueue::getMemoryDescriptor()
{
IOMemoryDescriptor *descriptor = 0;
- UInt32 queueSize;
-
- queueSize = ((IODataQueueInternal *) notifyMsg)->queueSize;
+
if (dataQueue != 0) {
- descriptor = IOMemoryDescriptor::withAddress(dataQueue, queueSize + DATA_QUEUE_MEMORY_HEADER_SIZE, kIODirectionOutIn);
+ descriptor = IOMemoryDescriptor::withAddress(dataQueue, dataQueue->queueSize + DATA_QUEUE_MEMORY_HEADER_SIZE, kIODirectionOutIn);
}
return descriptor;
}
-