/* * Copyright (c) 1998-2003 Apple Computer, Inc. All rights reserved. * * @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. 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_LICENSE_HEADER_END@ */ /*! * @header IOStorage * @abstract * This header contains the IOStorage class definition. */ #ifndef _IOSTORAGE_H #define _IOSTORAGE_H #include <IOKit/IOTypes.h> /*! * @defined kIOStorageClass * @abstract * The name of the IOStorage class. */ #define kIOStorageClass "IOStorage" /*! * @enum IOStorageAccess * @discussion * The IOStorageAccess enumeration describes the possible access levels for open * requests. * @constant kIOStorageAccessNone * No access is requested; should not be passed to open(). * @constant kIOStorageAccessReader * Read-only access is requested. * @constant kIOStorageAccessReaderWriter * Read and write access is requested. */ typedef UInt32 IOStorageAccess; #define kIOStorageAccessNone 0x00 #define kIOStorageAccessReader 0x01 #define kIOStorageAccessReaderWriter 0x03 /*! * @defined kIOStorageCategory * @abstract * kIOStorageCategory is a value for IOService's kIOMatchCategoryKey property. * @discussion * The kIOStorageCategory value is the standard value for the IOService property * kIOMatchCategoryKey ("IOMatchCategory") for all storage drivers. All storage * objects that expect to drive new content (that is, produce new media objects) * are expected to compete within the kIOStorageCategory namespace. * * See the IOService documentation for more information on match categories. */ #define kIOStorageCategory "IOStorage" /* (as IOMatchCategory) */ #ifdef KERNEL #ifdef __cplusplus /* * Kernel */ #include <IOKit/assert.h> #include <IOKit/IOMemoryDescriptor.h> #include <IOKit/IOService.h> /*! * @typedef IOStorageCompletionAction * @discussion * The IOStorageCompletionAction declaration describes the C (or C++) completion * routine that is called once an asynchronous storage operation completes. * @param target * Opaque client-supplied pointer (or an instance pointer for a C++ callback). * @param parameter * Opaque client-supplied pointer. * @param status * Status of the data transfer. * @param actualByteCount * Actual number of bytes transferred in the data transfer. */ typedef void (*IOStorageCompletionAction)(void * target, void * parameter, IOReturn status, UInt64 actualByteCount); /*! * @struct IOStorageCompletion * @discussion * The IOStorageCompletion structure describes the C (or C++) completion routine * that is called once an asynchronous storage operation completes. The values * passed for the target and parameter fields will be passed to the routine when * it is called. * @field target * Opaque client-supplied pointer (or an instance pointer for a C++ callback). * @field action * Completion routine to call on completion of the data transfer. * @field parameter * Opaque client-supplied pointer. */ struct IOStorageCompletion { void * target; IOStorageCompletionAction action; void * parameter; }; /*! * @class IOStorage * @abstract * The common base class for mass storage objects. * @discussion * The IOStorage class is the common base class for mass storage objects. It is * an abstract class that defines the open/close/read/write APIs that need to be * implemented in a given subclass. Synchronous versions of the read/write APIs * are provided here -- they are coded in such a way as to wrap the asynchronous * versions implemented in the subclass. */ class IOStorage : public IOService { OSDeclareAbstractStructors(IOStorage); protected: struct ExpansionData { /* */ }; ExpansionData * _expansionData; /*! * @function handleOpen * @discussion * The handleOpen method grants or denies permission to access this object * to an interested client. The argument is an IOStorageAccess value that * specifies the level of access desired -- reader or reader-writer. * * This method can be invoked to upgrade or downgrade the access level for * an existing client as well. The previous access level will prevail for * upgrades that fail, of course. A downgrade should never fail. If the * new access level should be the same as the old for a given client, this * method will do nothing and return success. In all cases, one, singular * close-per-client is expected for all opens-per-client received. * @param client * Client requesting the open. * @param options * Options for the open. Set to zero. * @param access * Access level for the open. Set to kIOStorageAccessReader or * kIOStorageAccessReaderWriter. * @result * Returns true if the open was successful, false otherwise. */ virtual bool handleOpen(IOService * client, IOOptionBits options, void * access) = 0; /*! * @function handleIsOpen * @discussion * The handleIsOpen method determines whether the specified client, or any * client if none is specified, presently has an open on this object. * @param client * Client to check the open state of. Set to zero to check the open state * of all clients. * @result * Returns true if the client was (or clients were) open, false otherwise. */ virtual bool handleIsOpen(const IOService * client) const = 0; /*! * @function handleClose * @discussion * The handleClose method closes the client's access to this object. * @param client * Client requesting the close. * @param options * Options for the close. Set to zero. */ virtual void handleClose(IOService * client, IOOptionBits options) = 0; public: /*! * @function open * @discussion * Ask the storage object for permission to access its contents; the method * is equivalent to IOService::open(), but with the correct parameter types. * * This method may also be invoked to upgrade or downgrade the access of an * existing open (if it fails, the existing open prevails). * @param client * Client requesting the open. * @param options * Options for the open. Set to zero. * @param access * Access level for the open. Set to kIOStorageAccessReader or * kIOStorageAccessReaderWriter. * @result * Returns true if the open was successful, false otherwise. */ virtual bool open(IOService * client, IOOptionBits options, IOStorageAccess access); /*! * @function read * @discussion * Read data from the storage object at the specified byte offset into the * specified buffer, asynchronously. When the read completes, the caller * will be notified via the specified completion action. * * The buffer will be retained for the duration of the read. * @param client * Client requesting the read. * @param byteStart * Starting byte offset for the data transfer. * @param buffer * Buffer for the data transfer. The size of the buffer implies the size of * the data transfer. * @param completion * Completion routine to call once the data transfer is complete. */ virtual void read(IOService * client, UInt64 byteStart, IOMemoryDescriptor * buffer, IOStorageCompletion completion) = 0; /*! * @function write * @discussion * Write data into the storage object at the specified byte offset from the * specified buffer, asynchronously. When the write completes, the caller * will be notified via the specified completion action. * * The buffer will be retained for the duration of the write. * @param client * Client requesting the write. * @param byteStart * Starting byte offset for the data transfer. * @param buffer * Buffer for the data transfer. The size of the buffer implies the size of * the data transfer. * @param completion * Completion routine to call once the data transfer is complete. */ virtual void write(IOService * client, UInt64 byteStart, IOMemoryDescriptor * buffer, IOStorageCompletion completion) = 0; /*! * @function read * @discussion * Read data from the storage object at the specified byte offset into the * specified buffer, synchronously. When the read completes, this method * will return to the caller. The actual byte count field is optional. * @param client * Client requesting the read. * @param byteStart * Starting byte offset for the data transfer. * @param buffer * Buffer for the data transfer. The size of the buffer implies the size of * the data transfer. * @param actualByteCount * Returns the actual number of bytes transferred in the data transfer. * @result * Returns the status of the data transfer. */ virtual IOReturn read(IOService * client, UInt64 byteStart, IOMemoryDescriptor * buffer, UInt64 * actualByteCount = 0); /*! * @function write * @discussion * Write data into the storage object at the specified byte offset from the * specified buffer, synchronously. When the write completes, this method * will return to the caller. The actual byte count field is optional. * @param client * Client requesting the write. * @param byteStart * Starting byte offset for the data transfer. * @param buffer * Buffer for the data transfer. The size of the buffer implies the size of * the data transfer. * @param actualByteCount * Returns the actual number of bytes transferred in the data transfer. * @result * Returns the status of the data transfer. */ virtual IOReturn write(IOService * client, UInt64 byteStart, IOMemoryDescriptor * buffer, UInt64 * actualByteCount = 0); /*! * @function synchronizeCache * @discussion * Flush the cached data in the storage object, if any, synchronously. * @param client * Client requesting the cache synchronization. * @result * Returns the status of the cache synchronization. */ virtual IOReturn synchronizeCache(IOService * client) = 0; /*! * @function complete * @discussion * Invokes the specified completion action of the read/write request. If * the completion action is unspecified, no action is taken. This method * serves simply as a convenience to storage subclass developers. * @param completion * Completion information for the data transfer. * @param status * Status of the data transfer. * @param actualByteCount * Actual number of bytes transferred in the data transfer. */ static void complete(IOStorageCompletion completion, IOReturn status, UInt64 actualByteCount = 0); OSMetaClassDeclareReservedUnused(IOStorage, 0); OSMetaClassDeclareReservedUnused(IOStorage, 1); OSMetaClassDeclareReservedUnused(IOStorage, 2); OSMetaClassDeclareReservedUnused(IOStorage, 3); OSMetaClassDeclareReservedUnused(IOStorage, 4); OSMetaClassDeclareReservedUnused(IOStorage, 5); OSMetaClassDeclareReservedUnused(IOStorage, 6); OSMetaClassDeclareReservedUnused(IOStorage, 7); OSMetaClassDeclareReservedUnused(IOStorage, 8); OSMetaClassDeclareReservedUnused(IOStorage, 9); OSMetaClassDeclareReservedUnused(IOStorage, 10); OSMetaClassDeclareReservedUnused(IOStorage, 11); OSMetaClassDeclareReservedUnused(IOStorage, 12); OSMetaClassDeclareReservedUnused(IOStorage, 13); OSMetaClassDeclareReservedUnused(IOStorage, 14); OSMetaClassDeclareReservedUnused(IOStorage, 15); }; #endif /* __cplusplus */ #endif /* KERNEL */ #endif /* !_IOSTORAGE_H */