DrvChar.cpp@ 56292

Last change on this file since 56292 was 56292, checked in by vboxsync, 10 years ago
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1	/* $Id: DrvChar.cpp 56292 2015-06-09 14:20:46Z vboxsync $ */
2	/** @file
3	* Driver that adapts PDMISTREAM into PDMICHARCONNECTOR / PDMICHARPORT.
4	*
5	* Converts synchronous calls (PDMICHARCONNECTOR::pfnWrite, PDMISTREAM::pfnRead)
6	* into asynchronous ones.
7	*
8	* Note that we don't use a send buffer here to be able to handle
9	* dropping of bytes for xmit at device level.
10	*/
11
12	/*
13	* Copyright (C) 2006-2015 Oracle Corporation
14	*
15	* This file is part of VirtualBox Open Source Edition (OSE), as
16	* available from http://www.virtualbox.org. This file is free software;
17	* you can redistribute it and/or modify it under the terms of the GNU
18	* General Public License (GPL) as published by the Free Software
19	* Foundation, in version 2 as it comes in the "COPYING" file of the
20	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
21	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
22	*/
23
24
25	/*******************************************************************************
26	* Header Files *
27	*******************************************************************************/
28	#define LOG_GROUP LOG_GROUP_DRV_CHAR
29	#include <VBox/vmm/pdmdrv.h>
30	#include <iprt/asm.h>
31	#include <iprt/assert.h>
32	#include <iprt/stream.h>
33	#include <iprt/semaphore.h>
34	#include <iprt/uuid.h>
35
36	#include "VBoxDD.h"
37
38
39	/*******************************************************************************
40	* Defined Constants And Macros *
41	*******************************************************************************/
42	/** Converts a pointer to DRVCHAR::ICharConnector to a PDRVCHAR. */
43	#define PDMICHAR_2_DRVCHAR(pInterface) RT_FROM_MEMBER(pInterface, DRVCHAR, ICharConnector)
44
45
46	/*******************************************************************************
47	* Structures and Typedefs *
48	*******************************************************************************/
49	/**
50	* Char driver instance data.
51	*
52	* @implements PDMICHARCONNECTOR
53	*/
54	typedef struct DRVCHAR
55	{
56	/** Pointer to the driver instance structure. */
57	PPDMDRVINS pDrvIns;
58	/** Pointer to the char port interface of the driver/device above us. */
59	PPDMICHARPORT pDrvCharPort;
60	/** Pointer to the stream interface of the driver below us. */
61	PPDMISTREAM pDrvStream;
62	/** Our char interface. */
63	PDMICHARCONNECTOR ICharConnector;
64	/** Flag to notify the receive thread it should terminate. */
65	volatile bool fShutdown;
66	/** Receive thread ID. */
67	RTTHREAD ReceiveThread;
68	/** Send thread ID. */
69	RTTHREAD SendThread;
70	/** Send event semaphore */
71	RTSEMEVENT SendSem;
72
73	/** Internal send FIFO queue */
74	uint8_t volatile u8SendByte;
75	bool volatile fSending;
76	uint8_t Alignment[2];
77
78	/** Read/write statistics */
79	STAMCOUNTER StatBytesRead;
80	STAMCOUNTER StatBytesWritten;
81	} DRVCHAR, *PDRVCHAR;
82	AssertCompileMemberAlignment(DRVCHAR, StatBytesRead, 8);
83
84
85
86
87	/* -=-=-=-=- IBase -=-=-=-=- */
88
89	/**
90	* @interface_method_impl{PDMIBASE,pfnQueryInterface}
91	*/
92	static DECLCALLBACK(void ) drvCharQueryInterface(PPDMIBASE pInterface, const char pszIID)
93	{
94	PPDMDRVINS pDrvIns = PDMIBASE_2_PDMDRV(pInterface);
95	PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
96
97	PDMIBASE_RETURN_INTERFACE(pszIID, PDMIBASE, &pDrvIns->IBase);
98	PDMIBASE_RETURN_INTERFACE(pszIID, PDMICHARCONNECTOR, &pThis->ICharConnector);
99	return NULL;
100	}
101
102
103	/* -=-=-=-=- ICharConnector -=-=-=-=- */
104
105	/** @copydoc PDMICHARCONNECTOR::pfnWrite */
106	static DECLCALLBACK(int) drvCharWrite(PPDMICHARCONNECTOR pInterface, const void *pvBuf, size_t cbWrite)
107	{
108	PDRVCHAR pThis = PDMICHAR_2_DRVCHAR(pInterface);
109	const char pbBuffer = (const char )pvBuf;
110
111	LogFlow(("%s: pvBuf=%#p cbWrite=%d\n", __FUNCTION__, pvBuf, cbWrite));
112
113	for (uint32_t i = 0; i < cbWrite; i++)
114	{
115	if (ASMAtomicXchgBool(&pThis->fSending, true))
116	return VERR_BUFFER_OVERFLOW;
117
118	pThis->u8SendByte = pbBuffer[i];
119	RTSemEventSignal(pThis->SendSem);
120	STAM_COUNTER_INC(&pThis->StatBytesWritten);
121	}
122	return VINF_SUCCESS;
123	}
124
125	/** @copydoc PDMICHARCONNECTOR::pfnSetParameters */
126	static DECLCALLBACK(int) drvCharSetParameters(PPDMICHARCONNECTOR pInterface, unsigned Bps, char chParity, unsigned cDataBits, unsigned cStopBits)
127	{
128	/PDRVCHAR pThis = PDMICHAR_2_DRVCHAR(pInterface); - unused/
129
130	LogFlow(("%s: Bps=%u chParity=%c cDataBits=%u cStopBits=%u\n", __FUNCTION__, Bps, chParity, cDataBits, cStopBits));
131	return VINF_SUCCESS;
132	}
133
134
135	/* -=-=-=-=- receive thread -=-=-=-=- */
136
137	/**
138	* Send thread loop - pushes data down thru the driver chain.
139	*
140	* @returns 0 on success.
141	* @param ThreadSelf Thread handle to this thread.
142	* @param pvUser User argument.
143	*/
144	static DECLCALLBACK(int) drvCharSendLoop(RTTHREAD ThreadSelf, void *pvUser)
145	{
146	PDRVCHAR pThis = (PDRVCHAR)pvUser;
147
148	int rc = VINF_SUCCESS;
149	while (!pThis->fShutdown)
150	{
151	RTMSINTERVAL cMillies = (rc == VERR_TIMEOUT) ? 50 : RT_INDEFINITE_WAIT;
152	rc = RTSemEventWait(pThis->SendSem, cMillies);
153	if ( RT_FAILURE(rc)
154	&& rc != VERR_TIMEOUT)
155	break;
156
157	/*
158	* Write the character to the attached stream (if present).
159	*/
160	if ( pThis->fShutdown
161	\|\| !pThis->pDrvStream)
162	break;
163
164	size_t cbProcessed = 1;
165	uint8_t ch = pThis->u8SendByte;
166	rc = pThis->pDrvStream->pfnWrite(pThis->pDrvStream, &ch, &cbProcessed);
167	if (RT_SUCCESS(rc))
168	{
169	ASMAtomicXchgBool(&pThis->fSending, false);
170	Assert(cbProcessed == 1);
171	}
172	else if (rc == VERR_TIMEOUT)
173	{
174	/* Normal case, just means that the stream didn't accept a new
175	* character before the timeout elapsed. Just retry. */
176
177	/* do not change the rc status here, otherwise the (rc == VERR_TIMEOUT) branch
178	* in the wait above will never get executed */
179	/* rc = VINF_SUCCESS; */
180	}
181	else
182	{
183	LogRel(("Write failed with %Rrc; skipping\n", rc));
184	break;
185	}
186	}
187
188	return VINF_SUCCESS;
189	}
190
191	/* -=-=-=-=- receive thread -=-=-=-=- */
192
193	/**
194	* Receive thread loop.
195	*
196	* @returns 0 on success.
197	* @param ThreadSelf Thread handle to this thread.
198	* @param pvUser User argument.
199	*/
200	static DECLCALLBACK(int) drvCharReceiveLoop(RTTHREAD ThreadSelf, void *pvUser)
201	{
202	PDRVCHAR pThis = (PDRVCHAR)pvUser;
203	char abBuffer[256];
204	char *pbRemaining = abBuffer;
205	size_t cbRemaining = 0;
206	int rc;
207
208	while (!pThis->fShutdown)
209	{
210	if (!cbRemaining)
211	{
212	/* Get block of data from stream driver. */
213	if (pThis->pDrvStream)
214	{
215	pbRemaining = abBuffer;
216	cbRemaining = sizeof(abBuffer);
217	rc = pThis->pDrvStream->pfnRead(pThis->pDrvStream, abBuffer, &cbRemaining);
218	if (RT_FAILURE(rc))
219	{
220	LogFlow(("Read failed with %Rrc\n", rc));
221	break;
222	}
223	}
224	else
225	RTThreadSleep(100);
226	}
227	else
228	{
229	/* Send data to guest. */
230	size_t cbProcessed = cbRemaining;
231	rc = pThis->pDrvCharPort->pfnNotifyRead(pThis->pDrvCharPort, pbRemaining, &cbProcessed);
232	if (RT_SUCCESS(rc))
233	{
234	Assert(cbProcessed);
235	pbRemaining += cbProcessed;
236	cbRemaining -= cbProcessed;
237	STAM_COUNTER_ADD(&pThis->StatBytesRead, cbProcessed);
238	}
239	else if (rc == VERR_TIMEOUT)
240	{
241	/* Normal case, just means that the guest didn't accept a new
242	* character before the timeout elapsed. Just retry. */
243	rc = VINF_SUCCESS;
244	}
245	else
246	{
247	LogFlow(("NotifyRead failed with %Rrc\n", rc));
248	break;
249	}
250	}
251	}
252
253	return VINF_SUCCESS;
254	}
255
256	/**
257	* Set the modem lines.
258	*
259	* @returns VBox status code
260	* @param pInterface Pointer to the interface structure.
261	* @param RequestToSend Set to true if this control line should be made active.
262	* @param DataTerminalReady Set to true if this control line should be made active.
263	*/
264	static DECLCALLBACK(int) drvCharSetModemLines(PPDMICHARCONNECTOR pInterface, bool RequestToSend, bool DataTerminalReady)
265	{
266	/* Nothing to do here. */
267	return VINF_SUCCESS;
268	}
269
270	/**
271	* Sets the TD line into break condition.
272	*
273	* @returns VBox status code.
274	* @param pInterface Pointer to the interface structure containing the called function pointer.
275	* @param fBreak Set to true to let the device send a break false to put into normal operation.
276	* @thread Any thread.
277	*/
278	static DECLCALLBACK(int) drvCharSetBreak(PPDMICHARCONNECTOR pInterface, bool fBreak)
279	{
280	/* Nothing to do here. */
281	return VINF_SUCCESS;
282	}
283
284	/* -=-=-=-=- driver interface -=-=-=-=- */
285
286	/**
287	* Destruct a char driver instance.
288	*
289	* Most VM resources are freed by the VM. This callback is provided so that
290	* any non-VM resources can be freed correctly.
291	*
292	* @param pDrvIns The driver instance data.
293	*/
294	static DECLCALLBACK(void) drvCharDestruct(PPDMDRVINS pDrvIns)
295	{
296	PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
297	LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance));
298	PDMDRV_CHECK_VERSIONS_RETURN_VOID(pDrvIns);
299
300	/*
301	* Tell the threads to shut down.
302	*/
303	pThis->fShutdown = true;
304	if (pThis->SendSem != NIL_RTSEMEVENT)
305	{
306	RTSemEventSignal(pThis->SendSem);
307	pThis->SendSem = NIL_RTSEMEVENT;
308	}
309
310	/*
311	* Wait for the threads.
312	* ASSUMES that PDM destroys the driver chain from the bottom and up.
313	*/
314	if (pThis->ReceiveThread != NIL_RTTHREAD)
315	{
316	int rc = RTThreadWait(pThis->ReceiveThread, 30000, NULL);
317	if (RT_SUCCESS(rc))
318	pThis->ReceiveThread = NIL_RTTHREAD;
319	else
320	LogRel(("Char%d: receive thread did not terminate (%Rrc)\n", pDrvIns->iInstance, rc));
321	}
322
323	if (pThis->SendThread != NIL_RTTHREAD)
324	{
325	int rc = RTThreadWait(pThis->SendThread, 30000, NULL);
326	if (RT_SUCCESS(rc))
327	pThis->SendThread = NIL_RTTHREAD;
328	else
329	LogRel(("Char%d: send thread did not terminate (%Rrc)\n", pDrvIns->iInstance, rc));
330	}
331
332	if (pThis->SendSem != NIL_RTSEMEVENT)
333	{
334	RTSemEventDestroy(pThis->SendSem);
335	pThis->SendSem = NIL_RTSEMEVENT;
336	}
337	}
338
339
340	/**
341	* Construct a char driver instance.
342	*
343	* @copydoc FNPDMDRVCONSTRUCT
344	*/
345	static DECLCALLBACK(int) drvCharConstruct(PPDMDRVINS pDrvIns, PCFGMNODE pCfg, uint32_t fFlags)
346	{
347	PDRVCHAR pThis = PDMINS_2_DATA(pDrvIns, PDRVCHAR);
348	LogFlow(("%s: iInstance=%d\n", __FUNCTION__, pDrvIns->iInstance));
349	PDMDRV_CHECK_VERSIONS_RETURN(pDrvIns);
350
351	/*
352	* Init basic data members and interfaces.
353	*/
354	pThis->fShutdown = false;
355	pThis->ReceiveThread = NIL_RTTHREAD;
356	pThis->SendThread = NIL_RTTHREAD;
357	pThis->SendSem = NIL_RTSEMEVENT;
358	/* IBase. */
359	pDrvIns->IBase.pfnQueryInterface = drvCharQueryInterface;
360	/* ICharConnector. */
361	pThis->ICharConnector.pfnWrite = drvCharWrite;
362	pThis->ICharConnector.pfnSetParameters = drvCharSetParameters;
363	pThis->ICharConnector.pfnSetModemLines = drvCharSetModemLines;
364	pThis->ICharConnector.pfnSetBreak = drvCharSetBreak;
365
366	/*
367	* Get the ICharPort interface of the above driver/device.
368	*/
369	pThis->pDrvCharPort = PDMIBASE_QUERY_INTERFACE(pDrvIns->pUpBase, PDMICHARPORT);
370	if (!pThis->pDrvCharPort)
371	return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_ABOVE, RT_SRC_POS, N_("Char#%d has no char port interface above"), pDrvIns->iInstance);
372
373	/*
374	* Attach driver below and query its stream interface.
375	*/
376	PPDMIBASE pBase;
377	int rc = PDMDrvHlpAttach(pDrvIns, fFlags, &pBase);
378	if (RT_FAILURE(rc))
379	return rc; /* Don't call PDMDrvHlpVMSetError here as we assume that the driver already set an appropriate error */
380	pThis->pDrvStream = PDMIBASE_QUERY_INTERFACE(pBase, PDMISTREAM);
381	if (!pThis->pDrvStream)
382	return PDMDrvHlpVMSetError(pDrvIns, VERR_PDM_MISSING_INTERFACE_BELOW, RT_SRC_POS, N_("Char#%d has no stream interface below"), pDrvIns->iInstance);
383
384	/*
385	* Don't start the receive thread if the driver doesn't support reading
386	*/
387	if (pThis->pDrvStream->pfnRead)
388	{
389	rc = RTThreadCreate(&pThis->ReceiveThread, drvCharReceiveLoop, (void *)pThis, 0,
390	RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "CharRecv");
391	if (RT_FAILURE(rc))
392	return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create receive thread"), pDrvIns->iInstance);
393	}
394
395	rc = RTSemEventCreate(&pThis->SendSem);
396	AssertRCReturn(rc, rc);
397
398	rc = RTThreadCreate(&pThis->SendThread, drvCharSendLoop, (void *)pThis, 0,
399	RTTHREADTYPE_IO, RTTHREADFLAGS_WAITABLE, "CharSend");
400	if (RT_FAILURE(rc))
401	return PDMDrvHlpVMSetError(pDrvIns, rc, RT_SRC_POS, N_("Char#%d cannot create send thread"), pDrvIns->iInstance);
402
403
404	PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesWritten, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes written", "/Devices/Char%d/Written", pDrvIns->iInstance);
405	PDMDrvHlpSTAMRegisterF(pDrvIns, &pThis->StatBytesRead, STAMTYPE_COUNTER, STAMVISIBILITY_USED, STAMUNIT_BYTES, "Nr of bytes read", "/Devices/Char%d/Read", pDrvIns->iInstance);
406
407	return VINF_SUCCESS;
408	}
409
410
411	/**
412	* Char driver registration record.
413	*/
414	const PDMDRVREG g_DrvChar =
415	{
416	/* u32Version */
417	PDM_DRVREG_VERSION,
418	/* szName */
419	"Char",
420	/* szRCMod */
421	"",
422	/* szR0Mod */
423	"",
424	/* pszDescription */
425	"Generic char driver.",
426	/* fFlags */
427	PDM_DRVREG_FLAGS_HOST_BITS_DEFAULT,
428	/* fClass. */
429	PDM_DRVREG_CLASS_CHAR,
430	/* cMaxInstances */
431	~0U,
432	/* cbInstance */
433	sizeof(DRVCHAR),
434	/* pfnConstruct */
435	drvCharConstruct,
436	/* pfnDestruct */
437	drvCharDestruct,
438	/* pfnRelocate */
439	NULL,
440	/* pfnIOCtl */
441	NULL,
442	/* pfnPowerOn */
443	NULL,
444	/* pfnReset */
445	NULL,
446	/* pfnSuspend */
447	NULL,
448	/* pfnResume */
449	NULL,
450	/* pfnAttach */
451	NULL,
452	/* pfnDetach */
453	NULL,
454	/* pfnPowerOff */
455	NULL,
456	/* pfnSoftReset */
457	NULL,
458	/* u32EndVersion */
459	PDM_DRVREG_VERSION
460	};

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source: vbox/trunk/src/VBox/Devices/Serial/DrvChar.cpp@ 56292

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