1/*
2 * Copyright (c) 2005-2016 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28#ifndef _IODMACOMMAND_H
29#define _IODMACOMMAND_H
30
31#include <IOKit/IOCommand.h>
32#include <IOKit/IOMemoryDescriptor.h>
33class IOMapper;
34class IOBufferMemoryDescriptor;
35
36enum
37{
38 kIODMAMapOptionMapped = 0x00000000,
39 kIODMAMapOptionBypassed = 0x00000001,
40 kIODMAMapOptionNonCoherent = 0x00000002,
41 kIODMAMapOptionUnmapped = 0x00000003,
42 kIODMAMapOptionTypeMask = 0x0000000f,
43
44 kIODMAMapOptionNoCacheStore = 0x00000010, // Memory in descriptor
45 kIODMAMapOptionOnChip = 0x00000020, // Indicates DMA is on South Bridge
46 kIODMAMapOptionIterateOnly = 0x00000040 // DMACommand will be used as a cursor only
47};
48
49/**************************** class IODMACommand ***************************/
50
51/*!
52 @class IODMACommand
53 @abstract A mechanism to convert memory references to I/O bus addresses.
54 @discussion The IODMACommand is supersedes the IOMemoryCursor and greatly enhances the functionality and power of it. The command can be specified to output 64 bit physical addresses and also allows driver writers bypass mapping hardware or get addresses suitable for non-snooped DMA.
55<br><br>
56 The command is designed to be very easily subclassable. Most driver writers need to associate some DMA operations with their memory descriptor and usually use a C structure for that purpose. This structure is often kept in a linked list. This IODMACommand has built it <kern/queue.h> linkage and can be derived and 'public:' variables added, giving the developer a structure that can associate a memory descriptor with a particular dma command but will also allow the developer to generate that command and keep the state necessary for tracking it.
57<br><br>
58 It is envisaged that a pool of IODMACommands will be created at driver initialisation and each command will be kept in an IOCommandPool while not in use. However if developers wishes to maintain their own free lists that is certainly possible. See the <kern/queue.h> and <xnu/iokit/Kernel/IOCommandPool> for sample code on manipulating the command's doubly linked list entries.
59<br><br>
60 The IODMACommand can be used in a 'weak-linked' manner. To do this you must avoid using any static member functions. Use the, much slower but safe, weakWithSpecification function. On success a dma command instance will be returned. This instance can then be used to clone as many commands as is needed. Remember deriving from this class can not be done weakly, that is no weak subclassing!
61*/
62
63class IODMACommand : public IOCommand
64{
65 OSDeclareDefaultStructors(IODMACommand);
66
67friend class IODMAEventSource;
68
69public:
70
71/*!
72 @typedef Segment32
73 @discussion A 32 bit I/O bus address/length pair
74*/
75 struct Segment32 {
76 UInt32 fIOVMAddr, fLength;
77 };
78
79/*!
80 @typedef Segment64
81 @discussion A 64 bit I/O bus address/length pair
82*/
83 struct Segment64 {
84 UInt64 fIOVMAddr, fLength;
85 };
86
87/*! @enum MappingOptions
88 @abstract Mapping types to indicate the desired mapper type for translating memory descriptors into I/O DMA Bus addresses.
89 @constant kNonCoherent Used by drivers for non-coherent transfers, implies unmapped memmory
90 @constant kMapped Allow a driver to define addressing size
91 @constant kBypassed Allow drivers to bypass any mapper
92 @constant kMaxMappingOptions Internal use only
93*/
94 enum MappingOptions {
95 kMapped = kIODMAMapOptionMapped,
96 kBypassed = kIODMAMapOptionBypassed,
97 kNonCoherent = kIODMAMapOptionNonCoherent,
98 kUnmapped = kIODMAMapOptionUnmapped,
99 kTypeMask = kIODMAMapOptionTypeMask,
100
101 kNoCacheStore = kIODMAMapOptionNoCacheStore, // Memory in descriptor
102 kOnChip = kIODMAMapOptionOnChip, // Indicates DMA is on South Bridge
103 kIterateOnly = kIODMAMapOptionIterateOnly // DMACommand will be used as a cursor only
104 };
105
106 struct SegmentOptions {
107 uint8_t fStructSize;
108 uint8_t fNumAddressBits;
109 uint64_t fMaxSegmentSize;
110 uint64_t fMaxTransferSize;
111 uint32_t fAlignment;
112 uint32_t fAlignmentLength;
113 uint32_t fAlignmentInternalSegments;
114 };
115
116/*! @enum SynchronizeOptions
117 @abstract Options for the synchronize method.
118 @constant kForceDoubleBuffer Copy the entire prepared range to a new page aligned buffer.
119*/
120 enum SynchronizeOptions {
121 kForceDoubleBuffer = 0x01000000
122 };
123
124/*!
125 @typedef SegmentFunction
126 @discussion Pointer to a C function that translates a 64 segment and outputs a single desired segment to the array at the requested index. There are a group of pre-implemented SegmentFunctions that may be usefull to the developer below.
127 @param segment The 64Bit I/O bus address and length.
128 @param segments Base of the output vector of DMA address length pairs.
129 @param segmentIndex Index to output 'segment' in the 'segments' array.
130 @result Returns true if segment encoding succeeded. false may be returned if the current segment does not fit in an output segment, i.e. a 38bit address wont fit into a 32 encoding.
131*/
132 typedef bool (*SegmentFunction)(IODMACommand *target,
133 Segment64 segment,
134 void *segments,
135 UInt32 segmentIndex);
136
137 // -------------- Preimplemented output functions ----------------
138
139/*! @function OutputHost32
140 @abstract Output host natural Segment32 output segment function.
141*/
142 static bool OutputHost32(IODMACommand *target,
143 Segment64 seg, void *segs, UInt32 ind);
144
145/*! @defined kIODMACommandOutputHost32
146 @abstract Output host natural Segment32 output segment function.
147 */
148#define kIODMACommandOutputHost32 (IODMACommand::OutputHost32)
149
150/*! @function OutputBig32
151 @abstract Output big-endian Segment32 output segment function.
152*/
153 static bool OutputBig32(IODMACommand *target,
154 Segment64 seg, void *segs, UInt32 ind);
155
156/*! @defined kIODMACommandOutputBig32
157 @abstract Output big-endian Segment32 output segment function.
158 */
159#define kIODMACommandOutputBig32 (IODMACommand::OutputBig32)
160
161/*! @function OutputLittle32
162 @abstract Output little-endian Segment32 output segment function.
163*/
164 static bool OutputLittle32(IODMACommand *target,
165 Segment64 seg, void *segs, UInt32 ind);
166
167/*! @defined kIODMACommandOutputLittle32
168 @abstract Output little-endian Segment32 output segment function.
169*/
170#define kIODMACommandOutputLittle32 (IODMACommand::OutputLittle32)
171
172/*! @function OutputHost64
173 @abstract Output host natural Segment64 output segment function.
174*/
175 static bool OutputHost64(IODMACommand *target,
176 Segment64 seg, void *segs, UInt32 ind);
177
178/*! @defined kIODMACommandOutputHost64
179 @abstract Output host natural Segment64 output segment function.
180*/
181#define kIODMACommandOutputHost64 (IODMACommand::OutputHost64)
182
183/*! @function OutputBig64
184 @abstract Output big-endian Segment64 output segment function.
185*/
186 static bool OutputBig64(IODMACommand *target,
187 Segment64 seg, void *segs, UInt32 ind);
188
189/*! @defined kIODMACommandOutputBig64
190 @abstract Output big-endian Segment64 output segment function.
191*/
192#define kIODMACommandOutputBig64 (IODMACommand::OutputBig64)
193
194/*! @function OutputLittle64
195 @abstract Output little-endian Segment64 output segment function.
196*/
197 static bool OutputLittle64(IODMACommand *target,
198 Segment64 seg, void *segs, UInt32 ind);
199
200/*! @defined kIODMACommandOutputLittle64
201 @abstract Output little-endian Segment64 output segment function.
202*/
203#define kIODMACommandOutputLittle64 (IODMACommand::OutputLittle64)
204
205/*! @function withSpecification
206 @abstract Creates and initializes an IODMACommand in one operation.
207 @discussion Factory function to create and initialize an IODMACommand in one operation.
208 @param outSegFunc SegmentFunction to call to output one physical segment. A set of nine commonly required segment functions are provided.
209 @param numAddressBits Number of bits that the hardware uses on its internal address bus. Typically 32 but may be more on modern hardware. A 0 implies no-restriction other than that implied by the output segment function.
210 @param maxSegmentSize Maximum allowable size for one segment. If 0 is passed the maximum segment size is unlimited.
211 @param mappingOptions is the type of mapping that is required to translate an IOMemoryDescriptor into the desired number of bits. For instance if your hardware only supports 32 bits but must run on machines with > 4G of RAM some mapping will be required. Number of bits will be specified in numAddressBits, see below.This parameter can take 3 values:- kNonCoherent - used for non-coherent hardware transfers, Mapped - Validate that all I/O bus generated addresses are within the number of addressing bits specified, Bypassed indicates that bypassed addressing is required, this is used when the hardware transferes are into coherent memory but no mapping is required. See also prepare() for failure cases.
212 @param maxTransferSize Maximum size of an entire transfer. Defaults to 0 indicating no maximum.
213 @param alignment Alignment restriction, in bytes, on I/O bus addresses. Defaults to single byte alignment.
214 @param mapper For mapping types kMapped & kBypassed mapper is used to define the hardware that will perform the mapping, defaults to the system mapper.
215 @param refCon Reference Constant
216 @result Returns a new IODMACommand if successfully created and initialized, 0 otherwise.
217*/
218 static IODMACommand *
219 withSpecification(SegmentFunction outSegFunc,
220 UInt8 numAddressBits,
221 UInt64 maxSegmentSize,
222 MappingOptions mappingOptions = kMapped,
223 UInt64 maxTransferSize = 0,
224 UInt32 alignment = 1,
225 IOMapper *mapper = 0,
226 void *refCon = 0);
227
228/*! @function weakWithSpecification
229 @abstract Creates and initialises an IODMACommand in one operation if this version of the operating system supports it.
230 @discussion Factory function to create and initialise an IODMACommand in one operation. The function allows a developer to 'weak' link with IODMACommand. This function will return kIOReturnUnsupported if the IODMACommand is unavailable. This function is actually fairly slow so it will be better to call it once then clone the successfully create command using cloneCommand (q.v.).
231 @param newCommand Output reference variable of the newly created IODMACommand.
232 @param outSegFunc SegmentFunction to call to output one physical segment. A set of nine commonly required segment functions are provided.
233 @param numAddressBits Number of bits that the hardware uses on its internal address bus. Typically 32 but may be more on modern hardware. A 0 implies no-restriction other than that implied by the output segment function.
234 @param maxSegmentSize Maximum allowable size for one segment. Zero is treated as an unlimited segment size.
235 @param mapType is the type of mapping that is required to translate an IOMemoryDescriptor into the desired number of bits. For instance if your hardware only supports 32 bits but must run on machines with > 4G of RAM some mapping will be required. Number of bits will be specified in numAddressBits, see below. This parameter can take 3 values:- kNonCoherent - used for non-coherent hardware transfers, Mapped - Validate that all I/O bus generated addresses are within the number of addressing bits specified, Bypassed indicates that bypassed addressing is required, this is used when the hardware transfers are into coherent memory but no mapping is required. See also prepare() for failure cases.
236 @param maxTransferSize Maximum size of an entire transfer. Defaults to 0 indicating no maximum.
237 @param alignment Alignment restriction, in bytes, on I/O bus addresses. Defaults to single byte alignment.
238 @param mapper For mapping types kMapped & kBypassed mapper is used to define the hardware that will perform the mapping, defaults to the system mapper.
239 @param refCon Reference Constant
240 @result kIOReturnSuccess if everything is OK, otherwise kIOReturnBadArgument if newCommand is NULL, kIOReturnUnsupported if the kernel doesn't export IODMACommand or IOReturnError if the new command fails to init, q.v. initWithSpecification.
241*/
242 // Note that the function has the attribute always_inline.
243 // The point of this function is to make a call into the kernel
244 // without generating an undefined symbol. If the client could call
245 // the code as a function then the goal of no undefined symbols
246 // would be lost thus defeating the purpose.
247 static inline IOReturn weakWithSpecification
248 (IODMACommand **newCommand,
249 SegmentFunction outSegFunc,
250 UInt8 numAddressBits,
251 UInt64 maxSegmentSize,
252 MappingOptions mapType = kMapped,
253 UInt64 maxTransferSize = 0,
254 UInt32 alignment = 1,
255 IOMapper *mapper = 0,
256 void *refCon = 0) __attribute__((always_inline));
257
258 static IODMACommand *
259 withSpecification(SegmentFunction outSegFunc,
260 const SegmentOptions * segmentOptions,
261 uint32_t mappingOptions,
262 IOMapper * mapper,
263 void * refCon);
264
265
266/*! @function withRefCon
267 @abstract Creates and initializes an unspecified IODMACommand.
268 @discussion Factory function to create and initialize an unspecified IODMACommand. prepareWithSpecification() must be used to prepare the IODMACommand before use.
269 @param refCon Reference Constant
270 @result Returns a new IODMACommand if successfully created and initialized, 0 otherwise.
271*/
272 static IODMACommand * withRefCon(void * refCon);
273
274/*!
275 @function cloneCommand
276 @abstract Creates a new command based on the specification of the current one.
277 @discussion Factory function to create and initialise an IODMACommand in one operation. The current command's specification will be duplicated in the new object, but however none of its state will be duplicated. This means that it is safe to clone a command even if it is currently active and running, however you must be certain that the command to be duplicated does have a valid reference for the duration.
278 @result Returns a new IODMACommand if successfully created and initialised, 0 otherwise.
279*/
280 virtual IODMACommand *cloneCommand(void *refCon = 0);
281
282/*! @function initWithSpecification
283 @abstract Primary initializer for the IODMACommand class.
284 @param outSegFunc SegmentFunction to call to output one physical segment. A set of nine commonly required segment functions are provided.
285 @param numAddressBits Number of bits that the hardware uses on its internal address bus. Typically 32 but may be more on modern hardware. A 0 implies no-restriction other than that implied by the output segment function.
286 @param maxSegmentSize Maximum allowable size for one segment. Defaults to 0 which means any size.
287 @param mappingOptions is the type of mapping that is required to translate an IOMemoryDescriptor into the desired number of bits. For instance if your hardware only supports 32 bits but must run on machines with > 4G of RAM some mapping will be required. Number of bits will be specified in numAddressBits, see below.This parameter can take 3 values:- kNonCoherent - used for non-coherent hardware transfers, Mapped - Validate that all I/O bus generated addresses are within the number of addressing bits specified, Bypassed indicates that bypassed addressing is required, this is used when the hardware transferes are into coherent memory but no mapping is required. See also prepare() for failure cases.
288 @param maxTransferSize Maximum size of an entire transfer. Defaults to 0 indicating no maximum.
289 @param alignment Alignment restriction, in bytes, on I/O bus addresses. Defaults to single byte alignment.
290 @param mapper For mapping types kMapped & kBypassed mapper is used to define the hardware that will perform the mapping, defaults to the system mapper.
291 @param refCon Reference Constant
292 @result Can fail if the mapping type is not recognised, if one of the 3 mandatory parameters are set to 0, if a 32 bit output function is selected when more than 32 bits of address is required or, if kBypassed is requested on a machine that doesn't support bypassing. Returns true otherwise.
293*/
294 virtual bool initWithSpecification( SegmentFunction outSegFunc,
295 UInt8 numAddressBits,
296 UInt64 maxSegmentSize,
297 MappingOptions mappingOptions = kMapped,
298 UInt64 maxTransferSize = 0,
299 UInt32 alignment = 1,
300 IOMapper *mapper = 0,
301 void *refCon = 0);
302
303/*! @function setMemoryDescriptor
304 @abstract Sets and resets the DMACommand's current memory descriptor
305 @discussion The DMA command will configure itself based on the information that it finds in the memory descriptor. It looks for things like the direction of the memory descriptor and whether the current memory descriptor is already mapped into some IOMMU. As a programmer convenience it can also prepare the DMA command immediately. See prepare(). Note the IODMACommand is designed to used multiple times with a succession of memory descriptors, making the pooling of commands possible. It is an error though to attempt to reset a currently prepared() DMA command. Warning: This routine may block so never try to autoprepare an IODMACommand while in a gated context, i.e. one of the WorkLoops action call outs.
306 @param mem A pointer to the current I/Os memory descriptor.
307 @param autoPrepare An optional boolean variable that will call the prepare() function automatically after the memory descriptor is processed. Defaults to true.
308 @result Returns kIOReturnSuccess, kIOReturnBusy if currently prepared, kIOReturnNoSpace if the length(mem) >= Maximum Transfer Size or the error codes returned by prepare() (qv).
309*/
310 virtual IOReturn setMemoryDescriptor(const IOMemoryDescriptor *mem,
311 bool autoPrepare = true);
312
313/*! @function clearMemoryDescriptor
314 @abstract Clears the DMACommand's current memory descriptor
315 @discussion completes and invalidates the cache if the DMA command is currently active, copies all data from bounce buffers if necessary and releases all resources acquired during setMemoryDescriptor.
316 @param autoComplete An optional boolean variable that will call the complete() function automatically before the memory descriptor is processed. Defaults to true.
317*/
318 virtual IOReturn clearMemoryDescriptor(bool autoComplete = true);
319
320/*! @function getMemoryDescriptor
321 @abstract Get the current memory descriptor
322*/
323 virtual const IOMemoryDescriptor *getMemoryDescriptor() const;
324
325/*! @function getIOMemoryDescriptor
326 @abstract Get the memory descriptor to be used for DMA
327*/
328 IOMemoryDescriptor * getIOMemoryDescriptor() const;
329
330/*! @function prepare
331 @abstract Prepare the memory for an I/O transfer.
332 @discussion Allocate the mapping resources neccessary for this transfer, specifying a sub range of the IOMemoryDescriptor that will be the target of the I/O. The complete() method frees these resources. Data may be copied to buffers for kIODirectionOut memory descriptors, depending on hardware mapping resource availabilty or alignment restrictions. It should be noted that the this function may block and should only be called on the clients context, i.e never call this routine while gated; also the call itself is not thread safe though this should be an issue as each IODMACommand is independant.
333 @param offset defines the starting offset in the memory descriptor the DMA command will operate on. genIOVMSegments will produce its results based on the offset and length passed to the prepare method.
334 @param length defines the ending position in the memory descriptor the DMA command will operate on. genIOVMSegments will produce its results based on the offset and length passed to the prepare method.
335 @param flushCache Flush the caches for the memory descriptor and make certain that the memory cycles are complete. Defaults to true for kNonCoherent and is ignored by the other types.
336 @param synchronize Copy any buffered data back from the target IOMemoryDescriptor. Defaults to true, if synchronize() is being used to explicitly copy data, passing false may avoid an unneeded copy.
337 @result An IOReturn code. */
338
339 virtual IOReturn prepare(UInt64 offset = 0, UInt64 length = 0, bool flushCache = true, bool synchronize = true);
340
341/*! @function complete
342 @abstract Complete processing of DMA mappings after an I/O transfer is finished.
343 @discussion This method should not be called unless a prepare was previously issued; the prepare() and complete() must occur in pairs, before and after an I/O transfer
344 @param invalidateCache Invalidate the caches for the memory descriptor. Defaults to true for kNonCoherent and is ignored by the other types.
345 @param synchronize Copy any buffered data back to the target IOMemoryDescriptor. Defaults to true, if synchronize() is being used to explicitly copy data, passing false may avoid an unneeded copy.
346 @result kIOReturnNotReady if not prepared, kIOReturnSuccess otherwise. */
347
348 virtual IOReturn complete(bool invalidateCache = true, bool synchronize = true);
349
350/*! @function synchronize
351 @abstract Bring IOMemoryDescriptor and IODMACommand buffers into sync.
352 @discussion This method should not be called unless a prepare was previously issued. If needed a caller may synchronize any IODMACommand buffers with the original IOMemoryDescriptor buffers.
353 @param options Specifies the direction of the copy:
354 kIODirectionOut copy IOMemoryDesciptor memory to any IODMACommand buffers. By default this action takes place automatically at prepare().
355 kIODirectionIn copy any IODMACommand buffers back to the IOMemoryDescriptor. By default this action takes place automatically at complete().
356 kForceDoubleBuffer copy the entire prepared range to a new page aligned buffer.
357 @result kIOReturnNotReady if not prepared, kIOReturnBadArgument if invalid options are passed, kIOReturnSuccess otherwise. */
358
359 virtual IOReturn synchronize(IOOptionBits options);
360
361/*! @function genIOVMSegments
362 @abstract Generates a physical scatter/gather for the current DMA command
363 @discussion Generates a list of physical segments from the given memory descriptor, relative to the current position of the descriptor. The constraints that are set during initialisation will be respected. This function maintains the state across multiple calls for efficiency. However the state is discarded if the new offset is not the expected one.
364 @param offset input/output parameter, defines the starting and ending offset in the memory descriptor, relative to any offset passed to the prepare() method.
365 @param segments Void pointer to base of output physical scatter/gather list. Always passed directly onto the SegmentFunction.
366 @param numSegments Input/output parameter Number of segments that can fit in the segment array and returns number of segments generated.
367 @result kIOReturnSuccess on success, kIOReturnOverrun if the memory descriptor is exhausted, kIOReturnMessageTooLarge if the output segment function's address bits has insufficient resolution for a segment, kIOReturnNotReady if the DMA command has not be prepared, kIOReturnBadArgument if the DMA command doesn't have a memory descriptor yet or some of the parameters are NULL and kIOReturnNotReady if the DMA command is not prepared.
368*/
369 virtual IOReturn genIOVMSegments(UInt64 *offset,
370 void *segments,
371 UInt32 *numSegments);
372
373private:
374 virtual UInt64 transfer( IOOptionBits transferOp, UInt64 offset, void * buffer, UInt64 length );
375
376public:
377
378/*! @function writeBytes
379 @abstract Copy data to the IODMACommand's buffer from the specified buffer.
380 @discussion This method copies data to the IODMACommand's memory at the given offset, from the caller's buffer. The IODMACommand must be prepared, and the offset is relative to the prepared offset.
381 @param offset A byte offset into the IODMACommand's memory, relative to the prepared offset.
382 @param bytes The caller supplied buffer to copy the data from.
383 @param length The length of the data to copy.
384 @result The number of bytes copied, zero will be returned if the specified offset is beyond the prepared length of the IODMACommand. */
385
386 UInt64 writeBytes(UInt64 offset, const void *bytes, UInt64 length);
387
388/*! @function readBytes
389 @abstract Copy data from the IODMACommand's buffer to the specified buffer.
390 @discussion This method copies data from the IODMACommand's memory at the given offset, to the caller's buffer. The IODMACommand must be prepared, and the offset is relative to the prepared offset.
391 @param offset A byte offset into the IODMACommand's memory, relative to the prepared offset.
392 @param bytes The caller supplied buffer to copy the data to.
393 @param length The length of the data to copy.
394 @result The number of bytes copied, zero will be returned if the specified offset is beyond the prepared length of the IODMACommand. */
395
396 UInt64 readBytes(UInt64 offset, void *bytes, UInt64 length);
397
398/*! @function gen32IOVMSegments
399 @abstract Helper function for a type checked call to genIOVMSegments(qv), for use with an IODMACommand set up with the output function kIODMACommandOutputHost32, kIODMACommandOutputBig32, or kIODMACommandOutputLittle32. If the output function of the IODMACommand is not a 32 bit function, results will be incorrect.
400*/
401 inline IOReturn gen32IOVMSegments(UInt64 *offset,
402 Segment32 *segments,
403 UInt32 *numSegments)
404 { return genIOVMSegments(offset, segments, numSegments); }
405
406/*! @function gen64IOVMSegments
407 @abstract Helper function for a type checked call to genIOVMSegments(qv), for use with an IODMACommand set up with the output function kIODMACommandOutputHost64, kIODMACommandOutputBig64, or kIODMACommandOutputLittle64. If the output function of the IODMACommand is not a 64 bit function, results will be incorrect.
408*/
409 inline IOReturn gen64IOVMSegments(UInt64 *offset,
410 Segment64 *segments,
411 UInt32 *numSegments)
412 { return genIOVMSegments(offset, segments, numSegments); }
413
414 IOReturn
415 genIOVMSegments(SegmentFunction segmentFunction,
416 UInt64 *offsetP,
417 void *segmentsP,
418 UInt32 *numSegmentsP);
419
420 virtual void free() APPLE_KEXT_OVERRIDE;
421
422private:
423 IOReturn setSpecification(SegmentFunction outSegFunc,
424 const SegmentOptions * segmentOptions,
425 uint32_t mappingOptions,
426 IOMapper * mapper);
427
428 typedef IOReturn (*InternalSegmentFunction)(
429 void *reference,
430 IODMACommand *target,
431 Segment64 segment,
432 void *segments,
433 UInt32 segmentIndex);
434
435 IOReturn genIOVMSegments(uint32_t op,
436 InternalSegmentFunction outSegFunc,
437 void *reference,
438 UInt64 *offsetP,
439 void *segmentsP,
440 UInt32 *numSegmentsP);
441
442 static IOReturn clientOutputSegment(
443 void *reference, IODMACommand *target,
444 Segment64 segment, void *vSegList, UInt32 outSegIndex);
445
446 static IOReturn segmentOp(
447 void *reference,
448 IODMACommand *target,
449 Segment64 segment,
450 void *segments,
451 UInt32 segmentIndex);
452 IOReturn walkAll(UInt8 op);
453
454public:
455
456/*! @function prepareWithSpecification
457 @abstract Prepare the memory for an I/O transfer with a new specification.
458 @discussion Allocate the mapping resources neccessary for this transfer, specifying a sub range of the IOMemoryDescriptor that will be the target of the I/O. The complete() method frees these resources. Data may be copied to buffers for kIODirectionOut memory descriptors, depending on hardware mapping resource availabilty or alignment restrictions. It should be noted that the this function may block and should only be called on the clients context, i.e never call this routine while gated; also the call itself is not thread safe though this should be an issue as each IODMACommand is independant.
459 @param outSegFunc SegmentFunction to call to output one physical segment. A set of nine commonly required segment functions are provided.
460 @param numAddressBits Number of bits that the hardware uses on its internal address bus. Typically 32 but may be more on modern hardware. A 0 implies no-restriction other than that implied by the output segment function.
461 @param maxSegmentSize Maximum allowable size for one segment. Defaults to 0 which means any size.
462 @param mappingOptions is the type of mapping that is required to translate an IOMemoryDescriptor into the desired number of bits. For instance if your hardware only supports 32 bits but must run on machines with > 4G of RAM some mapping will be required. Number of bits will be specified in numAddressBits, see below.This parameter can take 3 values:- kNonCoherent - used for non-coherent hardware transfers, Mapped - Validate that all I/O bus generated addresses are within the number of addressing bits specified, Bypassed indicates that bypassed addressing is required, this is used when the hardware transferes are into coherent memory but no mapping is required. See also prepare() for failure cases.
463 @param maxTransferSize Maximum size of an entire transfer. Defaults to 0 indicating no maximum.
464 @param alignment Alignment restriction, in bytes, on I/O bus addresses. Defaults to single byte alignment.
465 @param mapper For mapping types kMapped & kBypassed mapper is used to define the hardware that will perform the mapping, defaults to the system mapper.
466 @param offset defines the starting offset in the memory descriptor the DMA command will operate on. genIOVMSegments will produce its results based on the offset and length passed to the prepare method.
467 @param length defines the ending position in the memory descriptor the DMA command will operate on. genIOVMSegments will produce its results based on the offset and length passed to the prepare method.
468 @param flushCache Flush the caches for the memory descriptor and make certain that the memory cycles are complete. Defaults to true for kNonCoherent and is ignored by the other types.
469 @param synchronize Copy any buffered data back from the target IOMemoryDescriptor. Defaults to true, if synchronize() is being used to explicitly copy data, passing false may avoid an unneeded copy.
470 @result An IOReturn code. Can fail if the mapping type is not recognised, if one of the 3 mandatory parameters are set to 0, if a 32 bit output function is selected when more than 32 bits of address is required or, if kBypassed is requested on a machine that doesn't support bypassing.
471*/
472
473 virtual IOReturn prepareWithSpecification(SegmentFunction outSegFunc,
474 UInt8 numAddressBits,
475 UInt64 maxSegmentSize,
476 MappingOptions mappingOptions = kMapped,
477 UInt64 maxTransferSize = 0,
478 UInt32 alignment = 1,
479 IOMapper *mapper = 0,
480 UInt64 offset = 0,
481 UInt64 length = 0,
482 bool flushCache = true,
483 bool synchronize = true);
484
485 static IOReturn transferSegment(void *reference,
486 IODMACommand *target,
487 Segment64 segment,
488 void *segments,
489 UInt32 segmentIndex);
490
491/*! @function getPreparedOffsetAndLength
492 @abstract Returns the offset and length into the target IOMemoryDescriptor of a prepared IODDMACommand.
493 @discussion If successfully prepared, returns the offset and length into the IOMemoryDescriptor. Will fail for an unprepared IODMACommand.
494 @param offset returns the starting offset in the memory descriptor the DMA command was prepared with. Pass NULL for don't care.
495 @param length returns the length in the memory descriptor the DMA command was prepared with. Pass NULL for don't care.
496 @result An IOReturn code. kIOReturnNotReady if the IODMACommand is not prepared. */
497
498 virtual IOReturn getPreparedOffsetAndLength(UInt64 * offset, UInt64 * length);
499
500 UInt8 getNumAddressBits(void);
501 UInt32 getAlignment(void);
502 uint32_t getAlignmentLength(void);
503 uint32_t getAlignmentInternalSegments(void);
504
505
506/*! @function initWithRefCon
507 @abstract Secondary initializer for the IODMACommand class.
508 @param refCon Reference Constant
509 @result Can fail if super init fails. Returns true otherwise.
510*/
511
512 virtual
513 bool initWithRefCon(void * refCon = 0);
514
515 virtual
516 bool initWithSpecification(SegmentFunction outSegFunc,
517 const SegmentOptions * segmentOptions,
518 uint32_t mappingOptions,
519 IOMapper * mapper,
520 void * refCon);
521
522 virtual
523 IOReturn prepareWithSpecification(SegmentFunction outSegFunc,
524 const SegmentOptions * segmentOptions,
525 uint32_t mappingOptions,
526 IOMapper * mapper,
527 uint64_t offset,
528 uint64_t length,
529 bool flushCache = true,
530 bool synchronize = true);
531
532 virtual
533 IOBufferMemoryDescriptor * createCopyBuffer(IODirection direction, UInt64 length);
534
535private:
536 OSMetaClassDeclareReservedUsed(IODMACommand, 0);
537 OSMetaClassDeclareReservedUsed(IODMACommand, 1);
538 OSMetaClassDeclareReservedUsed(IODMACommand, 2);
539 OSMetaClassDeclareReservedUsed(IODMACommand, 3);
540 OSMetaClassDeclareReservedUsed(IODMACommand, 4);
541 OSMetaClassDeclareReservedUsed(IODMACommand, 5);
542 OSMetaClassDeclareReservedUsed(IODMACommand, 6);
543 OSMetaClassDeclareReservedUnused(IODMACommand, 7);
544 OSMetaClassDeclareReservedUnused(IODMACommand, 8);
545 OSMetaClassDeclareReservedUnused(IODMACommand, 9);
546 OSMetaClassDeclareReservedUnused(IODMACommand, 10);
547 OSMetaClassDeclareReservedUnused(IODMACommand, 11);
548 OSMetaClassDeclareReservedUnused(IODMACommand, 12);
549 OSMetaClassDeclareReservedUnused(IODMACommand, 13);
550 OSMetaClassDeclareReservedUnused(IODMACommand, 14);
551 OSMetaClassDeclareReservedUnused(IODMACommand, 15);
552
553public:
554/*! @var fRefCon Reference Constant, client defined publicly avialable */
555 void *fRefCon;
556
557protected:
558
559/*! @var fMaxSegmentSize Maximum size of one segment in a scatter/gather list */
560 UInt64 fMaxSegmentSize;
561
562/*! @var fMaxTransferSize
563 Maximum size of a transfer that this memory cursor is allowed to generate */
564 UInt64 fMaxTransferSize;
565
566 UInt32 fAlignMaskLength;
567 UInt32 fAlignMaskInternalSegments;
568
569/*! @var fMapper
570 Client defined mapper. */
571 IOMapper *fMapper;
572
573/*! @var fMemory
574 memory descriptor for current I/O. */
575 const IOMemoryDescriptor *fMemory;
576
577/*! @var fOutSeg The action method called when an event has been delivered */
578 SegmentFunction fOutSeg;
579
580/*! @var fAlignMask
581 Alignment restriction mask. */
582 UInt32 fAlignMask;
583
584/*! @var fNumAddressBits
585 Number of bits that the hardware can address */
586 UInt32 fNumAddressBits;
587
588/*! @var fNumSegments
589 Number of contiguous segments required for the current memory descriptor and desired mapping */
590 UInt32 fNumSegments;
591
592/*! @var fMappingOptions
593 What type of I/O virtual address mapping is required for this command */
594 uint32_t fMappingOptions;
595
596/*! @var fActive
597 fActive indicates that this DMA command is currently prepared and ready to go */
598 UInt32 fActive;
599
600/*! @var reserved
601 Reserved for future use. (Internal use only) */
602 struct IODMACommandInternal * reserved;
603};
604
605IOReturn IODMACommand::
606weakWithSpecification(IODMACommand **newCommand,
607 SegmentFunction outSegFunc,
608 UInt8 numAddressBits,
609 UInt64 maxSegmentSize,
610 MappingOptions mapType,
611 UInt64 maxTransferSize,
612 UInt32 alignment,
613 IOMapper *mapper,
614 void *refCon)
615{
616 if (!newCommand)
617 return kIOReturnBadArgument;
618
619 IODMACommand *self = (IODMACommand *)
620 OSMetaClass::allocClassWithName("IODMACommand");
621 if (!self)
622 return kIOReturnUnsupported;
623
624 IOReturn ret;
625 bool inited = self->
626 initWithSpecification(outSegFunc,
627 numAddressBits, maxSegmentSize, mapType,
628 maxTransferSize, alignment, mapper, refCon);
629 if (inited)
630 ret = kIOReturnSuccess;
631 else {
632 self->release();
633 self = 0;
634 ret = kIOReturnError;
635 }
636
637 *newCommand = self;
638 return ret;
639};
640#endif /* !_IODMACOMMAND_H */
641
642