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--- xnu/xnu-10063.121.3/iokit/Kernel/IOSharedDataQueue.cpp
+++ /dev/null
@@ -1,423 +0,0 @@
-/*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
- *
- * @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. 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
- * 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.
- *
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
- */
-
-#define IOKIT_ENABLE_SHARED_PTR
-
-#include <IOKit/IOSharedDataQueue.h>
-#include <IOKit/IODataQueueShared.h>
-#include <IOKit/IOLib.h>
-#include <IOKit/IOMemoryDescriptor.h>
-#include <libkern/c++/OSSharedPtr.h>
-
-#ifdef enqueue
-#undef enqueue
-#endif
-
-#ifdef dequeue
-#undef dequeue
-#endif
-
-#define super IODataQueue
-
-OSDefineMetaClassAndStructors(IOSharedDataQueue, IODataQueue)
-
-OSSharedPtr<IOSharedDataQueue>
-IOSharedDataQueue::withCapacity(UInt32 size)
-{
- OSSharedPtr<IOSharedDataQueue> dataQueue = OSMakeShared<IOSharedDataQueue>();
-
- if (dataQueue) {
- if (!dataQueue->initWithCapacity(size)) {
- return nullptr;
- }
- }
-
- return dataQueue;
-}
-
-OSSharedPtr<IOSharedDataQueue>
-IOSharedDataQueue::withEntries(UInt32 numEntries, UInt32 entrySize)
-{
- OSSharedPtr<IOSharedDataQueue> dataQueue = OSMakeShared<IOSharedDataQueue>();
-
- if (dataQueue) {
- if (!dataQueue->initWithEntries(numEntries, entrySize)) {
- return nullptr;
- }
- }
-
- return dataQueue;
-}
-
-Boolean
-IOSharedDataQueue::initWithCapacity(UInt32 size)
-{
- IODataQueueAppendix * appendix;
- vm_size_t allocSize;
- kern_return_t kr;
-
- if (!super::init()) {
- return false;
- }
-
- _reserved = IOMallocType(ExpansionData);
- if (!_reserved) {
- return false;
- }
-
- if (size > UINT32_MAX - DATA_QUEUE_MEMORY_HEADER_SIZE - DATA_QUEUE_MEMORY_APPENDIX_SIZE) {
- return false;
- }
-
- allocSize = round_page(size + DATA_QUEUE_MEMORY_HEADER_SIZE + DATA_QUEUE_MEMORY_APPENDIX_SIZE);
-
- if (allocSize < size) {
- return false;
- }
-
- kr = kmem_alloc(kernel_map, (vm_offset_t *)&dataQueue, allocSize,
- (kma_flags_t)(KMA_DATA | KMA_ZERO), IOMemoryTag(kernel_map));
- if (kr != KERN_SUCCESS) {
- return false;
- }
-
- dataQueue->queueSize = size;
-// dataQueue->head = 0;
-// dataQueue->tail = 0;
-
- if (!setQueueSize(size)) {
- return false;
- }
-
- appendix = (IODataQueueAppendix *)((UInt8 *)dataQueue + size + DATA_QUEUE_MEMORY_HEADER_SIZE);
- appendix->version = 0;
-
- if (!notifyMsg) {
- notifyMsg = IOMallocType(mach_msg_header_t);
- if (!notifyMsg) {
- return false;
- }
- }
- bzero(notifyMsg, sizeof(mach_msg_header_t));
-
- setNotificationPort(MACH_PORT_NULL);
-
- return true;
-}
-
-void
-IOSharedDataQueue::free()
-{
- if (dataQueue) {
- kmem_free(kernel_map, (vm_offset_t)dataQueue, round_page(getQueueSize() +
- DATA_QUEUE_MEMORY_HEADER_SIZE + DATA_QUEUE_MEMORY_APPENDIX_SIZE));
- dataQueue = NULL;
- if (notifyMsg) {
- IOFreeType(notifyMsg, mach_msg_header_t);
- notifyMsg = NULL;
- }
- }
-
- if (_reserved) {
- IOFreeType(_reserved, ExpansionData);
- _reserved = NULL;
- }
-
- super::free();
-}
-
-OSSharedPtr<IOMemoryDescriptor>
-IOSharedDataQueue::getMemoryDescriptor()
-{
- OSSharedPtr<IOMemoryDescriptor> descriptor;
-
- if (dataQueue != NULL) {
- descriptor = IOMemoryDescriptor::withAddress(dataQueue, getQueueSize() + DATA_QUEUE_MEMORY_HEADER_SIZE + DATA_QUEUE_MEMORY_APPENDIX_SIZE, kIODirectionOutIn);
- }
-
- return descriptor;
-}
-
-
-IODataQueueEntry *
-IOSharedDataQueue::peek()
-{
- IODataQueueEntry *entry = NULL;
- UInt32 headOffset;
- UInt32 tailOffset;
-
- if (!dataQueue) {
- return NULL;
- }
-
- // Read head and tail with acquire barrier
- // See rdar://problem/40780584 for an explanation of relaxed/acquire barriers
- headOffset = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED);
- tailOffset = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->tail, __ATOMIC_ACQUIRE);
-
- if (headOffset != tailOffset) {
- volatile IODataQueueEntry * head = NULL;
- UInt32 headSize = 0;
- UInt32 headOffset = dataQueue->head;
- UInt32 queueSize = getQueueSize();
-
- if (headOffset > queueSize) {
- return NULL;
- }
-
- head = (IODataQueueEntry *)((char *)dataQueue->queue + headOffset);
- headSize = head->size;
-
- // Check if there's enough room before the end of the queue for a header.
- // If there is room, check if there's enough room to hold the header and
- // the data.
-
- if ((headOffset > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) ||
- (headOffset + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize) ||
- (headOffset + DATA_QUEUE_ENTRY_HEADER_SIZE > UINT32_MAX - headSize) ||
- (headOffset + headSize + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize)) {
- // No room for the header or the data, wrap to the beginning of the queue.
- // Note: wrapping even with the UINT32_MAX checks, as we have to support
- // queueSize of UINT32_MAX
- entry = dataQueue->queue;
- } else {
- entry = (IODataQueueEntry *)head;
- }
- }
-
- return entry;
-}
-
-Boolean
-IOSharedDataQueue::enqueue(void * data, UInt32 dataSize)
-{
- UInt32 head;
- UInt32 tail;
- UInt32 newTail;
- const UInt32 entrySize = dataSize + DATA_QUEUE_ENTRY_HEADER_SIZE;
- IODataQueueEntry * entry;
-
- // Force a single read of head and tail
- // See rdar://problem/40780584 for an explanation of relaxed/acquire barriers
- tail = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->tail, __ATOMIC_RELAXED);
- head = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_ACQUIRE);
-
- // Check for overflow of entrySize
- if (dataSize > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) {
- return false;
- }
- // Check for underflow of (getQueueSize() - tail)
- if (getQueueSize() < tail || getQueueSize() < head) {
- return false;
- }
-
- if (tail >= head) {
- // Is there enough room at the end for the entry?
- if ((entrySize <= UINT32_MAX - tail) &&
- ((tail + entrySize) <= getQueueSize())) {
- entry = (IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail);
-
- entry->size = dataSize;
- __nochk_memcpy(&entry->data, data, dataSize);
-
- // The tail can be out of bound when the size of the new entry
- // 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?
- // Wrap around to the beginning, but do not allow the tail to catch
- // up to the head.
-
- dataQueue->queue->size = dataSize;
-
- // We need to make sure that there is enough room to set the size before
- // 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 ((getQueueSize() - tail) >= DATA_QUEUE_ENTRY_HEADER_SIZE) {
- ((IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail))->size = dataSize;
- }
-
- __nochk_memcpy(&dataQueue->queue->data, data, dataSize);
- newTail = entrySize;
- } else {
- return false; // queue is full
- }
- } else {
- // Do not allow the tail to catch up to the head when the queue is full.
- // That's why the comparison uses a '>' rather than '>='.
-
- if ((head - tail) > entrySize) {
- entry = (IODataQueueEntry *)((UInt8 *)dataQueue->queue + tail);
-
- entry->size = dataSize;
- __nochk_memcpy(&entry->data, data, dataSize);
- newTail = tail + entrySize;
- } else {
- return false; // queue is full
- }
- }
-
- // Publish the data we just enqueued
- __c11_atomic_store((_Atomic UInt32 *)&dataQueue->tail, newTail, __ATOMIC_RELEASE);
-
- if (tail != head) {
- //
- // The memory barrier below paris with the one in ::dequeue
- // so that either our store to the tail cannot be missed by
- // the next dequeue attempt, or we will observe the dequeuer
- // making the queue empty.
- //
- // Of course, if we already think the queue is empty,
- // there's no point paying this extra cost.
- //
- __c11_atomic_thread_fence(__ATOMIC_SEQ_CST);
- head = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED);
- }
-
- if (tail == head) {
- // Send notification (via mach message) that data is now available.
- sendDataAvailableNotification();
- }
- return true;
-}
-
-Boolean
-IOSharedDataQueue::dequeue(void *data, UInt32 *dataSize)
-{
- Boolean retVal = TRUE;
- volatile IODataQueueEntry * entry = NULL;
- UInt32 entrySize = 0;
- UInt32 headOffset = 0;
- UInt32 tailOffset = 0;
- UInt32 newHeadOffset = 0;
-
- if (!dataQueue || (data && !dataSize)) {
- return false;
- }
-
- // Read head and tail with acquire barrier
- // See rdar://problem/40780584 for an explanation of relaxed/acquire barriers
- headOffset = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->head, __ATOMIC_RELAXED);
- tailOffset = __c11_atomic_load((_Atomic UInt32 *)&dataQueue->tail, __ATOMIC_ACQUIRE);
-
- if (headOffset != tailOffset) {
- volatile IODataQueueEntry * head = NULL;
- UInt32 headSize = 0;
- UInt32 queueSize = getQueueSize();
-
- if (headOffset > queueSize) {
- return false;
- }
-
- head = (IODataQueueEntry *)((char *)dataQueue->queue + headOffset);
- headSize = head->size;
-
- // we wrapped around to beginning, so read from there
- // either there was not even room for the header
- if ((headOffset > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) ||
- (headOffset + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize) ||
- // or there was room for the header, but not for the data
- (headOffset + DATA_QUEUE_ENTRY_HEADER_SIZE > UINT32_MAX - headSize) ||
- (headOffset + headSize + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize)) {
- // Note: we have to wrap to the beginning even with the UINT32_MAX checks
- // because we have to support a queueSize of UINT32_MAX.
- entry = dataQueue->queue;
- entrySize = entry->size;
- if ((entrySize > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) ||
- (entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE > queueSize)) {
- return false;
- }
- newHeadOffset = entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE;
- // else it is at the end
- } else {
- entry = head;
- entrySize = entry->size;
- if ((entrySize > UINT32_MAX - DATA_QUEUE_ENTRY_HEADER_SIZE) ||
- (entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE > UINT32_MAX - headOffset) ||
- (entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE + headOffset > queueSize)) {
- return false;
- }
- newHeadOffset = headOffset + entrySize + DATA_QUEUE_ENTRY_HEADER_SIZE;
- }
- } else {
- // empty queue
- return false;
- }
-
- if (data) {
- if (entrySize > *dataSize) {
- // not enough space
- return false;
- }
- __nochk_memcpy(data, (void *)entry->data, entrySize);
- *dataSize = entrySize;
- }
-
- __c11_atomic_store((_Atomic UInt32 *)&dataQueue->head, newHeadOffset, __ATOMIC_RELEASE);
-
- if (newHeadOffset == tailOffset) {
- //
- // If we are making the queue empty, then we need to make sure
- // that either the enqueuer notices, or we notice the enqueue
- // that raced with our making of the queue empty.
- //
- __c11_atomic_thread_fence(__ATOMIC_SEQ_CST);
- }
-
- return retVal;
-}
-
-UInt32
-IOSharedDataQueue::getQueueSize()
-{
- if (!_reserved) {
- return 0;
- }
- return _reserved->queueSize;
-}
-
-Boolean
-IOSharedDataQueue::setQueueSize(UInt32 size)
-{
- if (!_reserved) {
- return false;
- }
- _reserved->queueSize = size;
- return true;
-}
-
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 0);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 1);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 2);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 3);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 4);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 5);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 6);
-OSMetaClassDefineReservedUnused(IOSharedDataQueue, 7);