DrvChar.cpp@ 106401

Last change on this file since 106401 was 106061, checked in by vboxsync, 3 months ago
Copyright year updates by scm.
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1	/* $Id: DrvChar.cpp 106061 2024-09-16 14:03:52Z vboxsync $ */
2	/** @file
3	* Driver that adapts PDMISTREAM into PDMISERIALCONNECTOR / PDMISERIALPORT.
4	*/
5
6	/*
7	* Copyright (C) 2006-2024 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* SPDX-License-Identifier: GPL-3.0-only
26	*/
27
28
29	/*********************************************************************************************************************************
30	* Header Files *
31	*********************************************************************************************************************************/
32	#define LOG_GROUP LOG_GROUP_DRV_CHAR
33	#include <VBox/vmm/pdmdrv.h>
34	#include <VBox/vmm/pdmserialifs.h>
35	#include <iprt/asm.h>
36	#include <iprt/assert.h>
37	#include <iprt/poll.h>
38	#include <iprt/stream.h>
39	#include <iprt/critsect.h>
40	#include <iprt/semaphore.h>
41	#include <iprt/uuid.h>
42
43	#include "VBoxDD.h"
44
45
46	/*********************************************************************************************************************************
47	* Defined Constants And Macros *
48	*********************************************************************************************************************************/
49
50
51	/*********************************************************************************************************************************
52	* Structures and Typedefs *
53	*********************************************************************************************************************************/
54	/**
55	* Char driver instance data.
56	*
57	* @implements PDMISERIALCONNECTOR
58	*/
59	typedef struct DRVCHAR
60	{
61	/** Pointer to the driver instance structure. */
62	PPDMDRVINS pDrvIns;
63	/** Pointer to the char port interface of the driver/device above us. */
64	PPDMISERIALPORT pDrvSerialPort;
65	/** Pointer to the stream interface of the driver below us. */
66	PPDMISTREAM pDrvStream;
67	/** Our serial interface. */
68	PDMISERIALCONNECTOR ISerialConnector;
69	/** Flag to notify the receive thread it should terminate. */
70	volatile bool fShutdown;
71	/** Flag whether data is available from the device/driver above as notified by the driver. */
72	volatile bool fAvailWrExt;
73	/** Internal copy of the flag which gets reset when there is no data anymore. */
74	bool fAvailWrInt;
75	/** I/O thread. */
76	PPDMTHREAD pThrdIo;
77
78	/** Small send buffer. */
79	uint8_t abTxBuf[16];
80	/** Amount of data in the buffer. */
81	size_t cbTxUsed;
82
83	/** Receive buffer. */
84	uint8_t abBuffer[256];
85	/** Number of bytes remaining in the receive buffer. */
86	volatile size_t cbRemaining;
87	/** Current position into the read buffer. */
88	uint8_t *pbBuf;
89
90	#if HC_ARCH_BITS == 32
91	uint32_t uAlignment0;
92	#endif
93
94	/** Read/write statistics */
95	STAMCOUNTER StatBytesRead;
96	STAMCOUNTER StatBytesWritten;
97	} DRVCHAR, *PDRVCHAR;
98	AssertCompileMemberAlignment(DRVCHAR, StatBytesRead, 8);
99
100
101
102
103	/* -=-=-=-=- IBase -=-=-=-=- */
104
105	/**
106	* @interface_method_impl{PDMIBASE,pfnQueryInterface}
107	*/
108	static DECLCALLBACK(void ) drvCharQueryInterface(PPDMIBASE pInterface, const char pszIID)
109	{
110	PPDMDRVINS pDrvIns = PDMIBASE_2_PDMDRV(pInterface);
111	PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
112
113	PDMIBASE_RETURN_INTERFACE(pszIID, PDMIBASE, &pDrvIns->IBase);
114	PDMIBASE_RETURN_INTERFACE(pszIID, PDMISERIALCONNECTOR, &pThis->ISerialConnector);
115	return NULL;
116	}
117
118
119	/* -=-=-=-=- ISerialConnector -=-=-=-=- */
120
121
122	/**
123	* @interface_method_impl{PDMISERIALCONNECTOR,pfnDataAvailWrNotify}
124	*/
125	static DECLCALLBACK(int) drvCharDataAvailWrNotify(PPDMISERIALCONNECTOR pInterface)
126	{
127	LogFlowFunc(("pInterface=%#p\n", pInterface));
128	PDRVCHAR pThis = RT_FROM_MEMBER(pInterface, DRVCHAR, ISerialConnector);
129
130	int rc = VINF_SUCCESS;
131	bool fAvailOld = ASMAtomicXchgBool(&pThis->fAvailWrExt, true);
132	if (!fAvailOld)
133	rc = pThis->pDrvStream->pfnPollInterrupt(pThis->pDrvStream);
134
135	return rc;
136	}
137
138
139	/**
140	* @interface_method_impl{PDMISERIALCONNECTOR,pfnReadRdr}
141	*/
142	static DECLCALLBACK(int) drvCharReadRdr(PPDMISERIALCONNECTOR pInterface, void pvBuf, size_t cbRead, size_t pcbRead)
143	{
144	LogFlowFunc(("pInterface=%#p pvBuf=%#p cbRead=%zu pcbRead=%#p\n", pInterface, pvBuf, cbRead, pcbRead));
145	PDRVCHAR pThis = RT_FROM_MEMBER(pInterface, DRVCHAR, ISerialConnector);
146	int rc = VINF_SUCCESS;
147
148	AssertReturn(pThis->cbRemaining, VERR_INVALID_STATE);
149	size_t cbToRead = RT_MIN(cbRead, pThis->cbRemaining);
150	memcpy(pvBuf, pThis->pbBuf, cbToRead);
151
152	pThis->pbBuf += cbToRead;
153	*pcbRead = cbToRead;
154	size_t cbOld = ASMAtomicSubZ(&pThis->cbRemaining, cbToRead);
155	if (!(cbOld - cbToRead)) /* Kick the I/O thread to fetch new data. */
156	rc = pThis->pDrvStream->pfnPollInterrupt(pThis->pDrvStream);
157	STAM_COUNTER_ADD(&pThis->StatBytesRead, cbToRead);
158
159	LogFlowFunc(("-> %Rrc\n", rc));
160	return rc;
161	}
162
163
164	/**
165	* @interface_method_impl{PDMISERIALCONNECTOR,pfnChgParams}
166	*/
167	static DECLCALLBACK(int) drvCharChgParams(PPDMISERIALCONNECTOR pInterface, uint32_t uBps,
168	PDMSERIALPARITY enmParity, unsigned cDataBits,
169	PDMSERIALSTOPBITS enmStopBits)
170	{
171	/* Nothing to do here. */
172	RT_NOREF(pInterface, uBps, enmParity, cDataBits, enmStopBits);
173	return VINF_SUCCESS;
174	}
175
176
177	/**
178	* @callback_method_impl{PDMISERIALCONNECTOR,pfnChgModemLines}
179	*/
180	static DECLCALLBACK(int) drvCharChgModemLines(PPDMISERIALCONNECTOR pInterface, bool fRts, bool fDtr)
181	{
182	/* Nothing to do here. */
183	RT_NOREF(pInterface, fRts, fDtr);
184	return VINF_SUCCESS;
185	}
186
187
188	/**
189	* @callback_method_impl{PDMISERIALCONNECTOR,pfnChgBrk}
190	*/
191	static DECLCALLBACK(int) drvCharChgBrk(PPDMISERIALCONNECTOR pInterface, bool fBrk)
192	{
193	/* Nothing to do here. */
194	RT_NOREF(pInterface, fBrk);
195	return VINF_SUCCESS;
196	}
197
198
199	/**
200	* @callback_method_impl{PDMISERIALCONNECTOR,pfnQueryStsLines}
201	*/
202	static DECLCALLBACK(int) drvCharQueryStsLines(PPDMISERIALCONNECTOR pInterface, uint32_t *pfStsLines)
203	{
204	/* Always carrier detect, data set read and clear to send. */
205	*pfStsLines = PDMISERIALPORT_STS_LINE_DCD \| PDMISERIALPORT_STS_LINE_DSR \| PDMISERIALPORT_STS_LINE_CTS;
206	RT_NOREF(pInterface);
207	return VINF_SUCCESS;
208	}
209
210
211	/**
212	* @callback_method_impl{PDMISERIALCONNECTOR,pfnQueuesFlush}
213	*/
214	static DECLCALLBACK(int) drvCharQueuesFlush(PPDMISERIALCONNECTOR pInterface, bool fQueueRecv, bool fQueueXmit)
215	{
216	RT_NOREF(fQueueXmit);
217	LogFlowFunc(("pInterface=%#p fQueueRecv=%RTbool fQueueXmit=%RTbool\n", pInterface, fQueueRecv, fQueueXmit));
218	int rc = VINF_SUCCESS;
219	PDRVCHAR pThis = RT_FROM_MEMBER(pInterface, DRVCHAR, ISerialConnector);
220
221	if (fQueueRecv)
222	{
223	size_t cbOld = 0;
224	cbOld = ASMAtomicXchgZ(&pThis->cbRemaining, 0);
225	if (cbOld) /* Kick the I/O thread to fetch new data. */
226	rc = pThis->pDrvStream->pfnPollInterrupt(pThis->pDrvStream);
227	}
228
229	LogFlowFunc(("-> %Rrc\n", rc));
230	return rc;
231	}
232
233
234	/* -=-=-=-=- I/O thread -=-=-=-=- */
235
236	/**
237	* Send thread loop - pushes data down thru the driver chain.
238	*
239	* @returns VBox status code.
240	* @param pDrvIns The char driver instance.
241	* @param pThread The worker thread.
242	*/
243	static DECLCALLBACK(int) drvCharIoLoop(PPDMDRVINS pDrvIns, PPDMTHREAD pThread)
244	{
245	RT_NOREF(pDrvIns);
246	PDRVCHAR pThis = (PDRVCHAR)pThread->pvUser;
247
248	if (pThread->enmState == PDMTHREADSTATE_INITIALIZING)
249	return VINF_SUCCESS;
250
251	while (pThread->enmState == PDMTHREADSTATE_RUNNING)
252	{
253	uint32_t fEvts = 0;
254
255	if (!pThis->fAvailWrInt)
256	pThis->fAvailWrInt = ASMAtomicXchgBool(&pThis->fAvailWrExt, false);
257
258	if ( !pThis->cbRemaining
259	&& pThis->pDrvStream->pfnRead)
260	fEvts \|= RTPOLL_EVT_READ;
261	if ( pThis->fAvailWrInt
262	\|\| pThis->cbTxUsed)
263	fEvts \|= RTPOLL_EVT_WRITE;
264
265	uint32_t fEvtsRecv = 0;
266	int rc = pThis->pDrvStream->pfnPoll(pThis->pDrvStream, fEvts, &fEvtsRecv, RT_INDEFINITE_WAIT);
267	if (RT_SUCCESS(rc))
268	{
269	if (fEvtsRecv & RTPOLL_EVT_WRITE)
270	{
271	if ( pThis->fAvailWrInt
272	&& pThis->cbTxUsed < RT_ELEMENTS(pThis->abTxBuf))
273	{
274	/* Stuff as much data into the TX buffer as we can. */
275	size_t cbToFetch = RT_ELEMENTS(pThis->abTxBuf) - pThis->cbTxUsed;
276	size_t cbFetched = 0;
277	rc = pThis->pDrvSerialPort->pfnReadWr(pThis->pDrvSerialPort, &pThis->abTxBuf[pThis->cbTxUsed], cbToFetch,
278	&cbFetched);
279	AssertRC(rc);
280
281	if (cbFetched > 0)
282	pThis->cbTxUsed += cbFetched;
283	else
284	{
285	/* There is no data available anymore. */
286	pThis->fAvailWrInt = false;
287	}
288	}
289
290	if (pThis->cbTxUsed)
291	{
292	size_t cbProcessed = pThis->cbTxUsed;
293	rc = pThis->pDrvStream->pfnWrite(pThis->pDrvStream, &pThis->abTxBuf[0], &cbProcessed);
294	if (RT_SUCCESS(rc))
295	{
296	pThis->cbTxUsed -= cbProcessed;
297	if ( pThis->cbTxUsed
298	&& cbProcessed)
299	{
300	/* Move the data in the TX buffer to the front to fill the end again. */
301	memmove(&pThis->abTxBuf[0], &pThis->abTxBuf[cbProcessed], pThis->cbTxUsed);
302	}
303	else
304	pThis->pDrvSerialPort->pfnDataSentNotify(pThis->pDrvSerialPort);
305	STAM_COUNTER_ADD(&pThis->StatBytesWritten, cbProcessed);
306	}
307	else if (rc != VERR_TIMEOUT)
308	{
309	LogRel(("Char#%d: Write failed with %Rrc; skipping\n", pDrvIns->iInstance, rc));
310	break;
311	}
312	}
313	}
314
315	if (fEvtsRecv & RTPOLL_EVT_READ)
316	{
317	AssertPtr(pThis->pDrvStream->pfnRead);
318	Assert(!pThis->cbRemaining);
319
320	size_t cbRead = sizeof(pThis->abBuffer);
321	rc = pThis->pDrvStream->pfnRead(pThis->pDrvStream, &pThis->abBuffer[0], &cbRead);
322	if (RT_FAILURE(rc))
323	{
324	LogFlow(("Read failed with %Rrc\n", rc));
325	break;
326	}
327
328	if (cbRead)
329	{
330	pThis->pbBuf = &pThis->abBuffer[0];
331	ASMAtomicWriteZ(&pThis->cbRemaining, cbRead);
332	/* Notify the upper device/driver. */
333	rc = pThis->pDrvSerialPort->pfnDataAvailRdrNotify(pThis->pDrvSerialPort, cbRead);
334	if (RT_FAILURE(rc))
335	{
336	LogRel(("Char#%d: Notifying upper driver about available data failed with %Rrc\n",
337	pDrvIns->iInstance, rc));
338	break;
339	}
340	}
341	}
342	}
343	else if (rc != VERR_INTERRUPTED)
344	LogRelMax(10, ("Char#%d: Polling failed with %Rrc\n", pDrvIns->iInstance, rc));
345	}
346
347	return VINF_SUCCESS;
348	}
349
350
351	/**
352	* Unblock the send worker thread so it can respond to a state change.
353	*
354	* @returns VBox status code.
355	* @param pDrvIns The char driver instance.
356	* @param pThread The worker thread.
357	*/
358	static DECLCALLBACK(int) drvCharIoLoopWakeup(PPDMDRVINS pDrvIns, PPDMTHREAD pThread)
359	{
360	PDRVCHAR pThis = (PDRVCHAR)pThread->pvUser;
361
362	RT_NOREF(pDrvIns);
363	return pThis->pDrvStream->pfnPollInterrupt(pThis->pDrvStream);
364	}
365
366
367	/* -=-=-=-=- driver interface -=-=-=-=- */
368
369	/**
370	* @interface_method_impl{PDMDRVREG,pfnReset}
371	*/
372	static DECLCALLBACK(void) drvCharReset(PPDMDRVINS pDrvIns)
373	{
374	PDMDRV_CHECK_VERSIONS_RETURN_VOID(pDrvIns);
375	PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
376
377	/* Reset TX and RX buffers. */
378	pThis->fAvailWrExt = false;
379	pThis->fAvailWrInt = false;
380	pThis->cbTxUsed = 0;
381	pThis->cbRemaining = 0;
382	}
383
384
385	/**
386	* Construct a char driver instance.
387	*
388	* @copydoc FNPDMDRVCONSTRUCT
389	*/
390	static DECLCALLBACK(int) drvCharConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
391	{
392	RT_NOREF(pCfg);
393	PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);
394	PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
395	LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance));
396
397	/*
398	* Init basic data members and interfaces.
399	*/
400	pThis->pDrvIns = pDrvIns;
401	pThis->pThrdIo = NIL_RTTHREAD;
402	/* IBase. */
403	pDrvIns->IBase.pfnQueryInterface = drvCharQueryInterface;
404	/* ISerialConnector. */
405	pThis->ISerialConnector.pfnDataAvailWrNotify = drvCharDataAvailWrNotify;
406	pThis->ISerialConnector.pfnReadRdr = drvCharReadRdr;
407	pThis->ISerialConnector.pfnChgParams = drvCharChgParams;
408	pThis->ISerialConnector.pfnChgModemLines = drvCharChgModemLines;
409	pThis->ISerialConnector.pfnChgBrk = drvCharChgBrk;
410	pThis->ISerialConnector.pfnQueryStsLines = drvCharQueryStsLines;
411	pThis->ISerialConnector.pfnQueuesFlush = drvCharQueuesFlush;
412
413	/*
414	* Get the ISerialPort interface of the above driver/device.
415	*/
416	pThis->pDrvSerialPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMISERIALPORT);
417	if (!pThis->pDrvSerialPort)
418	return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_ABOVE, RT_SRC_POS,
419	N_("Char#%d has no serial port interface above"), pDrvIns->iInstance);
420
421	/*
422	* Attach driver below and query its stream interface.
423	*/
424	PPDMIBASE pBase;
425	int rc = PDMDrvHlpAttach(pDrvIns, fFlags, &pBase);
426	if (RT_FAILURE(rc))
427	return rc; /* Don't call PDMDrvHlpVMSetError here as we assume that the driver already set an appropriate error */
428	pThis->pDrvStream = PDMIBASE_QUERY_INTERFACE(pBase, PDMISTREAM);
429	if (!pThis->pDrvStream)
430	return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW, RT_SRC_POS,
431	N_("Char#%d has no stream interface below"), pDrvIns->iInstance);
432
433	rc = PDMDrvHlpThreadCreate(pThis->pDrvIns, &pThis->pThrdIo, pThis, drvCharIoLoop,
434	drvCharIoLoopWakeup, 0, RTTHREADTYPE_IO, "CharIo");
435	if (RT_FAILURE(rc))
436	return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create I/O thread"), pDrvIns->iInstance);
437
438
439	PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesWritten, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES,
440	"Nr of bytes written", "/Devices/Char%d/Written", pDrvIns->iInstance);
441	PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesRead, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES,
442	"Nr of bytes read", "/Devices/Char%d/Read", pDrvIns->iInstance);
443
444	return VINF_SUCCESS;
445	}
446
447
448	/**
449	* Char driver registration record.
450	*/
451	const PDMDRVREG g_DrvChar =
452	{
453	/* u32Version */
454	PDM_DRVREG_VERSION,
455	/* szName */
456	"Char",
457	/* szRCMod */
458	"",
459	/* szR0Mod */
460	"",
461	/* pszDescription */
462	"Generic char driver.",
463	/* fFlags */
464	PDM_DRVREG_FLAGS_HOST_BITS_DEFAULT,
465	/* fClass. */
466	PDM_DRVREG_CLASS_CHAR,
467	/* cMaxInstances */
468	~0U,
469	/* cbInstance */
470	sizeof(DRVCHAR),
471	/* pfnConstruct */
472	drvCharConstruct,
473	/* pfnDestruct */
474	NULL,
475	/* pfnRelocate */
476	NULL,
477	/* pfnIOCtl */
478	NULL,
479	/* pfnPowerOn */
480	NULL,
481	/* pfnReset */
482	drvCharReset,
483	/* pfnSuspend */
484	NULL,
485	/* pfnResume */
486	NULL,
487	/* pfnAttach */
488	NULL,
489	/* pfnDetach */
490	NULL,
491	/* pfnPowerOff */
492	NULL,
493	/* pfnSoftReset */
494	NULL,
495	/* u32EndVersion */
496	PDM_DRVREG_VERSION
497	};

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source: vbox/trunk/src/VBox/Devices/Serial/DrvChar.cpp@ 106401

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