xnu-792.6.76.tar.gz

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

/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_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 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.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
#include <IOKit/assert.h>
#include <IOKit/system.h>

#include <IOKit/IOLib.h>
#include <IOKit/IOBufferMemoryDescriptor.h>

#include "IOKitKernelInternal.h"

__BEGIN_DECLS
void ipc_port_release_send(ipc_port_t port);
#include <vm/pmap.h>

vm_map_t IOPageableMapForAddress( vm_address_t address );
__END_DECLS

#define super IOGeneralMemoryDescriptor
OSDefineMetaClassAndStructors(IOBufferMemoryDescriptor,
				IOGeneralMemoryDescriptor);

bool IOBufferMemoryDescriptor::initWithAddress(
                                  void *      /* address       */ ,
                                  IOByteCount /* withLength    */ ,
                                  IODirection /* withDirection */ )
{
    return false;
}

bool IOBufferMemoryDescriptor::initWithAddress(
                                  vm_address_t /* address       */ ,
                                  IOByteCount  /* withLength    */ ,
                                  IODirection  /* withDirection */ ,
                                  task_t       /* withTask      */ )
{
    return false;
}

bool IOBufferMemoryDescriptor::initWithPhysicalAddress(
                                  IOPhysicalAddress /* address       */ ,
                                  IOByteCount       /* withLength    */ ,
                                  IODirection       /* withDirection */ )
{
    return false;
}

bool IOBufferMemoryDescriptor::initWithPhysicalRanges(
                                  IOPhysicalRange * /* ranges        */ ,
                                  UInt32            /* withCount     */ ,
                                  IODirection       /* withDirection */ ,
                                  bool              /* asReference   */ )
{
    return false;
}

bool IOBufferMemoryDescriptor::initWithRanges(
                                  IOVirtualRange * /* ranges        */ ,
                                  UInt32           /* withCount     */ ,
                                  IODirection      /* withDirection */ ,
                                  task_t           /* withTask      */ ,
                                  bool             /* asReference   */ )
{
    return false;
}

bool IOBufferMemoryDescriptor::initWithOptions(
                               IOOptionBits options,
                               vm_size_t    capacity,
                               vm_offset_t  alignment,
			       task_t	    inTask)
{
    kern_return_t 	kr;
    vm_map_t 		vmmap = 0;
    IOOptionBits	iomdOptions = kIOMemoryAsReference | kIOMemoryTypeVirtual;

    if (!capacity)
        return false;

    _options   	  = options;
    _capacity     = capacity;
    _physAddrs    = 0;
    _physSegCount = 0;
    _buffer	  = 0;

    // Grab the direction and the Auto Prepare bits from the Buffer MD options
    iomdOptions  |= options & (kIOMemoryDirectionMask | kIOMemoryAutoPrepare);

    if ((options & kIOMemorySharingTypeMask) && (alignment < page_size))
        alignment = page_size;

    if ((inTask != kernel_task) && !(options & kIOMemoryPageable))
        return false;

    _alignment = alignment;
    if (options & kIOMemoryPageable)
    {
        iomdOptions |= kIOMemoryBufferPageable;

        ipc_port_t sharedMem;
        vm_size_t size = round_page_32(capacity);

        // must create the entry before any pages are allocated

	// set flags for entry + object create
	vm_prot_t memEntryCacheMode = VM_PROT_READ | VM_PROT_WRITE
				    | MAP_MEM_NAMED_CREATE;

        if (options & kIOMemoryPurgeable)
            memEntryCacheMode |= MAP_MEM_PURGABLE;

	// set memory entry cache mode
	switch (options & kIOMapCacheMask)
	{
	    case kIOMapInhibitCache:
		SET_MAP_MEM(MAP_MEM_IO, memEntryCacheMode);
		break;
    
	    case kIOMapWriteThruCache:
		SET_MAP_MEM(MAP_MEM_WTHRU, memEntryCacheMode);
		break;

	    case kIOMapWriteCombineCache:
		SET_MAP_MEM(MAP_MEM_WCOMB, memEntryCacheMode);
		break;

	    case kIOMapCopybackCache:
		SET_MAP_MEM(MAP_MEM_COPYBACK, memEntryCacheMode);
		break;

	    case kIOMapDefaultCache:
	    default:
		SET_MAP_MEM(MAP_MEM_NOOP, memEntryCacheMode);
		break;
	}

	kr = mach_make_memory_entry( vmmap,
		    &size, 0,
		    memEntryCacheMode, &sharedMem,
		    NULL );

	if( (KERN_SUCCESS == kr) && (size != round_page_32(capacity))) {
	    ipc_port_release_send( sharedMem );
	    kr = kIOReturnVMError;
	}
	if( KERN_SUCCESS != kr)
	    return( false );

	_memEntry = (void *) sharedMem;
#if IOALLOCDEBUG
       debug_iomallocpageable_size += size;
#endif
	if ((NULL == inTask) && (options & kIOMemoryPageable))
	    inTask = kernel_task;
	else if (inTask == kernel_task)
	{
	    vmmap = kernel_map;
	}
	else
	{

	    if( !reserved) {
		reserved = IONew( ExpansionData, 1 );
		if( !reserved)
		    return( false );
	    }
	    vmmap = get_task_map(inTask);
	    vm_map_reference(vmmap);
	    reserved->map = vmmap;
	}
    }
    else 
    {
        // @@@ gvdl: Need to remove this
        // Buffer should never auto prepare they should be prepared explicitly
        // But it never was enforced so what are you going to do?
        iomdOptions |= kIOMemoryAutoPrepare;

	/* Allocate a wired-down buffer inside kernel space. */
	if (options & kIOMemoryPhysicallyContiguous)
	    _buffer = IOMallocContiguous(capacity, alignment, 0);
	else if (alignment > 1)
	    _buffer = IOMallocAligned(capacity, alignment);
	else
	    _buffer = IOMalloc(capacity);

	if (!_buffer)
	    return false;
    }

    _singleRange.v.address = (vm_address_t) _buffer;
    _singleRange.v.length  = capacity;

    if (!super::initWithOptions(&_singleRange.v, 1, 0,
                               inTask, iomdOptions, /* System mapper */ 0))
	return false;

    if (options & kIOMemoryPageable)
    {
        kern_return_t kr;

	if (vmmap)
	{
	    kr = doMap(vmmap, (IOVirtualAddress *) &_buffer, kIOMapAnywhere, 0, round_page_32(capacity));
	    if (KERN_SUCCESS != kr)
	    {
		_buffer = 0;
		return( false );
	    }
	    _singleRange.v.address = (vm_address_t) _buffer;
	}
    }

    setLength(capacity);
    
    return true;
}

IOBufferMemoryDescriptor * IOBufferMemoryDescriptor::inTaskWithOptions(
					    task_t       inTask,
                                            IOOptionBits options,
                                            vm_size_t    capacity,
                                            vm_offset_t  alignment)
{
    IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;
    
    if (me && !me->initWithOptions(options, capacity, alignment, inTask)) {
	me->release();
	me = 0;
    }
    return me;
}

bool IOBufferMemoryDescriptor::initWithOptions(
                               IOOptionBits options,
                               vm_size_t    capacity,
                               vm_offset_t  alignment)
{
    return( initWithOptions(options, capacity, alignment, kernel_task) );
}

IOBufferMemoryDescriptor * IOBufferMemoryDescriptor::withOptions(
                                            IOOptionBits options,
                                            vm_size_t    capacity,
                                            vm_offset_t  alignment)
{
    IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;
    
    if (me && !me->initWithOptions(options, capacity, alignment, kernel_task)) {
	me->release();
	me = 0;
    }
    return me;
}


/*
 * withCapacity:
 *
 * Returns a new IOBufferMemoryDescriptor with a buffer large enough to
 * hold capacity bytes.  The descriptor's length is initially set to the capacity.
 */
IOBufferMemoryDescriptor *
IOBufferMemoryDescriptor::withCapacity(vm_size_t   inCapacity,
                                       IODirection inDirection,
                                       bool        inContiguous)
{
    return( IOBufferMemoryDescriptor::withOptions(
               inDirection | kIOMemoryUnshared
                | (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
               inCapacity, inContiguous ? inCapacity : 1 ));
}

/*
 * initWithBytes:
 *
 * Initialize a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 * The descriptor's length and capacity are set to the input buffer's size.
 */
bool IOBufferMemoryDescriptor::initWithBytes(const void * inBytes,
                                             vm_size_t    inLength,
                                             IODirection  inDirection,
                                             bool         inContiguous)
{
    if (!initWithOptions(
               inDirection | kIOMemoryUnshared
                | (inContiguous ? kIOMemoryPhysicallyContiguous : 0),
               inLength, inLength ))
        return false;

    // start out with no data
    setLength(0);

    if (!appendBytes(inBytes, inLength))
        return false;

    return true;
}

/*
 * withBytes:
 *
 * Returns a new IOBufferMemoryDescriptor preloaded with bytes (copied).
 * The descriptor's length and capacity are set to the input buffer's size.
 */
IOBufferMemoryDescriptor *
IOBufferMemoryDescriptor::withBytes(const void * inBytes,
                                    vm_size_t    inLength,
                                    IODirection  inDirection,
                                    bool         inContiguous)
{
    IOBufferMemoryDescriptor *me = new IOBufferMemoryDescriptor;

    if (me && !me->initWithBytes(inBytes, inLength, inDirection, inContiguous)){
        me->release();
        me = 0;
    }
    return me;
}

/*
 * free:
 *
 * Free resources
 */
void IOBufferMemoryDescriptor::free()
{
    // Cache all of the relevant information on the stack for use
    // after we call super::free()!
    IOOptionBits options   = _options;
    vm_size_t    size	   = _capacity;
    void *       buffer	   = _buffer;
    vm_map_t	 vmmap	   = 0;
    vm_offset_t  alignment = _alignment;

    if (reserved)
    {
	vmmap = reserved->map;
        IODelete( reserved, ExpansionData, 1 );
    }

    /* super::free may unwire - deallocate buffer afterwards */
    super::free();

    if (options & kIOMemoryPageable)
    {
#if IOALLOCDEBUG
        if (!buffer || vmmap)
            debug_iomallocpageable_size -= round_page_32(size);
#endif
        if (buffer)
        {
            if (vmmap)
                vm_deallocate(vmmap, (vm_address_t) buffer, round_page_32(size));
            else
                IOFreePageable(buffer, size);
        }
    }
    else if (buffer)
    {
        if (options & kIOMemoryPhysicallyContiguous)
            IOFreeContiguous(buffer, size);
        else if (alignment > 1)
            IOFreeAligned(buffer, size);
        else
            IOFree(buffer, size);
    }
    if (vmmap)
	vm_map_deallocate(vmmap);
}

/*
 * getCapacity:
 *
 * Get the buffer capacity
 */
vm_size_t IOBufferMemoryDescriptor::getCapacity() const
{
    return _capacity;
}

/*
 * setLength:
 *
 * Change the buffer length of the memory descriptor.  When a new buffer
 * is created, the initial length of the buffer is set to be the same as
 * the capacity.  The length can be adjusted via setLength for a shorter
 * transfer (there is no need to create more buffer descriptors when you
 * can reuse an existing one, even for different transfer sizes).   Note
 * that the specified length must not exceed the capacity of the buffer.
 */
void IOBufferMemoryDescriptor::setLength(vm_size_t length)
{
    assert(length <= _capacity);

    _length = length;
    _singleRange.v.length = length;
}

/*
 * setDirection:
 *
 * Change the direction of the transfer.  This method allows one to redirect
 * the descriptor's transfer direction.  This eliminates the need to destroy
 * and create new buffers when different transfer directions are needed.
 */
void IOBufferMemoryDescriptor::setDirection(IODirection direction)
{
    _direction = direction;
}

/*
 * appendBytes:
 *
 * Add some data to the end of the buffer.  This method automatically
 * maintains the memory descriptor buffer length.  Note that appendBytes
 * will not copy past the end of the memory descriptor's current capacity.
 */
bool
IOBufferMemoryDescriptor::appendBytes(const void * bytes, vm_size_t withLength)
{
    vm_size_t actualBytesToCopy = min(withLength, _capacity - _length);

    assert(_length <= _capacity);
    bcopy(/* from */ bytes, (void *)(_singleRange.v.address + _length),
          actualBytesToCopy);
    _length += actualBytesToCopy;
    _singleRange.v.length += actualBytesToCopy;

    return true;
}

/*
 * getBytesNoCopy:
 *
 * Return the virtual address of the beginning of the buffer
 */
void * IOBufferMemoryDescriptor::getBytesNoCopy()
{
    return (void *)_singleRange.v.address;
}

/*
 * getBytesNoCopy:
 *
 * Return the virtual address of an offset from the beginning of the buffer
 */
void *
IOBufferMemoryDescriptor::getBytesNoCopy(vm_size_t start, vm_size_t withLength)
{
    if (start < _length && (start + withLength) <= _length)
        return (void *)(_singleRange.v.address + start);
    return 0;
}

OSMetaClassDefineReservedUsed(IOBufferMemoryDescriptor, 0);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 1);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 2);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 3);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 4);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 5);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 6);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 7);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 8);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 9);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 10);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 11);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 12);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 13);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 14);
OSMetaClassDefineReservedUnused(IOBufferMemoryDescriptor, 15);