ubuntu/vbox/r0drv/linux/semfastmutex-r0drv-linux.c

   1 /* $Id: semfastmutex-r0drv-linux.c $ */
   2 /** @file
   3  * IPRT - Fast Mutex Semaphores, Ring-0 Driver, Linux.
   4  */
   5
   6 /*
   7  * Copyright (C) 2006-2016 Oracle Corporation
   8  *
   9  * This file is part of VirtualBox Open Source Edition (OSE), as
  10  * available from http://www.virtualbox.org. This file is free software;
  11  * you can redistribute it and/or modify it under the terms of the GNU
  12  * General Public License (GPL) as published by the Free Software
  13  * Foundation, in version 2 as it comes in the "COPYING" file of the
  14  * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
  15  * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
  16  *
  17  * The contents of this file may alternatively be used under the terms
  18  * of the Common Development and Distribution License Version 1.0
  19  * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
  20  * VirtualBox OSE distribution, in which case the provisions of the
  21  * CDDL are applicable instead of those of the GPL.
  22  *
  23  * You may elect to license modified versions of this file under the
  24  * terms and conditions of either the GPL or the CDDL or both.
  25  */
  26
  27
  28 /*********************************************************************************************************************************
  29 *   Header Files                                                                                                                 *
  30 *********************************************************************************************************************************/
  31 #include "the-linux-kernel.h"
  32 #include "internal/iprt.h"
  33 #include <iprt/semaphore.h>
  34 #include <iprt/alloc.h>
  35 #include <iprt/assert.h>
  36 #include <iprt/asm.h>
  37 #include <iprt/err.h>
  38 #if defined(RT_STRICT) || defined(IPRT_DEBUG_SEMS)
  39 # include <iprt/thread.h>
  40 #endif
  41
  42 #include "internal/magics.h"
  43
  44
  45 /*********************************************************************************************************************************
  46 *   Structures and Typedefs                                                                                                      *
  47 *********************************************************************************************************************************/
  48 /**
  49  * Wrapper for the linux semaphore structure.
  50  */
  51 typedef struct RTSEMFASTMUTEXINTERNAL
  52 {
  53     /** Magic value (RTSEMFASTMUTEX_MAGIC). */
  54     uint32_t            u32Magic;
  55     /** the linux semaphore. */
  56     struct semaphore    Semaphore;
  57 #if defined(RT_STRICT) || defined(IPRT_DEBUG_SEMS)
  58     /** For check. */
  59     RTNATIVETHREAD volatile Owner;
  60 #endif
  61 } RTSEMFASTMUTEXINTERNAL, *PRTSEMFASTMUTEXINTERNAL;
  62
  63
  64 RTDECL(int)  RTSemFastMutexCreate(PRTSEMFASTMUTEX phFastMtx)
  65 {
  66     IPRT_LINUX_SAVE_EFL_AC();
  67
  68     /*
  69      * Allocate.
  70      */
  71     PRTSEMFASTMUTEXINTERNAL pThis;
  72     pThis = (PRTSEMFASTMUTEXINTERNAL)RTMemAlloc(sizeof(*pThis));
  73     if (!pThis)
  74         return VERR_NO_MEMORY;
  75
  76     /*
  77      * Initialize.
  78      */
  79     pThis->u32Magic = RTSEMFASTMUTEX_MAGIC;
  80     sema_init(&pThis->Semaphore, 1);
  81 #if defined(RT_STRICT) || defined(IPRT_DEBUG_SEMS)
  82     pThis->Owner = NIL_RTNATIVETHREAD;
  83 #endif
  84
  85     *phFastMtx = pThis;
  86     IPRT_LINUX_RESTORE_EFL_AC();
  87     return VINF_SUCCESS;
  88 }
  89 RT_EXPORT_SYMBOL(RTSemFastMutexCreate);
  90
  91
  92 RTDECL(int)  RTSemFastMutexDestroy(RTSEMFASTMUTEX hFastMtx)
  93 {
  94     /*
  95      * Validate.
  96      */
  97     PRTSEMFASTMUTEXINTERNAL pThis = hFastMtx;
  98     if (pThis == NIL_RTSEMFASTMUTEX)
  99         return VINF_SUCCESS;
 100     AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
 101     AssertMsgReturn(pThis->u32Magic == RTSEMFASTMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), VERR_INVALID_HANDLE);
 102
 103     ASMAtomicWriteU32(&pThis->u32Magic, RTSEMFASTMUTEX_MAGIC_DEAD);
 104     RTMemFree(pThis);
 105     return VINF_SUCCESS;
 106 }
 107 RT_EXPORT_SYMBOL(RTSemFastMutexDestroy);
 108
 109
 110 RTDECL(int)  RTSemFastMutexRequest(RTSEMFASTMUTEX hFastMtx)
 111 {
 112     IPRT_LINUX_SAVE_EFL_AC();
 113
 114     /*
 115      * Validate.
 116      */
 117     PRTSEMFASTMUTEXINTERNAL pThis = hFastMtx;
 118     AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
 119     AssertMsgReturn(pThis->u32Magic == RTSEMFASTMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), VERR_INVALID_HANDLE);
 120
 121     IPRT_DEBUG_SEMS_STATE(pThis, 'd');
 122     down(&pThis->Semaphore);
 123 #if defined(RT_STRICT) || defined(IPRT_DEBUG_SEMS)
 124     IPRT_DEBUG_SEMS_STATE(pThis, 'o');
 125     AssertRelease(pThis->Owner == NIL_RTNATIVETHREAD);
 126     ASMAtomicUoWriteSize(&pThis->Owner, RTThreadNativeSelf());
 127 #endif
 128
 129     IPRT_LINUX_RESTORE_EFL_ONLY_AC();
 130     return VINF_SUCCESS;
 131 }
 132 RT_EXPORT_SYMBOL(RTSemFastMutexRequest);
 133
 134
 135 RTDECL(int)  RTSemFastMutexRelease(RTSEMFASTMUTEX hFastMtx)
 136 {
 137     IPRT_LINUX_SAVE_EFL_AC();
 138
 139     /*
 140      * Validate.
 141      */
 142     PRTSEMFASTMUTEXINTERNAL pThis = hFastMtx;
 143     AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
 144     AssertMsgReturn(pThis->u32Magic == RTSEMFASTMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), VERR_INVALID_HANDLE);
 145
 146 #if defined(RT_STRICT) || defined(IPRT_DEBUG_SEMS)
 147     AssertRelease(pThis->Owner == RTThreadNativeSelf());
 148     ASMAtomicUoWriteSize(&pThis->Owner, NIL_RTNATIVETHREAD);
 149 #endif
 150     up(&pThis->Semaphore);
 151     IPRT_DEBUG_SEMS_STATE(pThis, 'u');
 152
 153     IPRT_LINUX_RESTORE_EFL_ONLY_AC();
 154     return VINF_SUCCESS;
 155 }
 156 RT_EXPORT_SYMBOL(RTSemFastMutexRelease);
 157