1    /*
     2     * Copyright (c) 2015, Texas Instruments Incorporated
     3     * All rights reserved.
     4     *
     5     * Redistribution and use in source and binary forms, with or without
     6     * modification, are permitted provided that the following conditions
     7     * are met:
     8     *
     9     * *  Redistributions of source code must retain the above copyright
    10     *    notice, this list of conditions and the following disclaimer.
    11     *
    12     * *  Redistributions in binary form must reproduce the above copyright
    13     *    notice, this list of conditions and the following disclaimer in the
    14     *    documentation and/or other materials provided with the distribution.
    15     *
    16     * *  Neither the name of Texas Instruments Incorporated nor the names of
    17     *    its contributors may be used to endorse or promote products derived
    18     *    from this software without specific prior written permission.
    19     *
    20     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    21     * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
    22     * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    23     * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
    24     * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
    25     * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
    26     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
    27     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
    28     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
    29     * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
    30     * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    31     */
    32    /*
    33     *  ======== GateSmp.xdc ========
    34     *
    35     */
    36    
    37    import xdc.rov.ViewInfo;
    38    import xdc.runtime.Assert;
    39    
    40    /*!
    41     *  ======== GateSmp ========
    42     *  Hwi, Swi & Task Gate
    43     *
    44     *  GateSmp uses disabling and enabling of interrupts, Swis and Tasks for the 
    45     *  resource locking mechanism. Such a gate guarantees exclusive access to the
    46     *  CPU. This gate can be used whenever the resource is being shared by Tasks,
    47     *  Swis, and/or Hwis. 
    48     *
    49     *  The duration between the enter and leave should be as short as possible
    50     *  to minimize Hwi latency.
    51     *
    52     *  GateSmp inherits from xdc.runtime.IGateProvider, therefore supports nesting.
    53     *
    54     *  @p(html)
    55     *  <h3> Calling Context </h3>
    56     *  <table border="1" cellpadding="3">
    57     *    <colgroup span="1"></colgroup> <colgroup span="5" align="center">
    58     *    </colgroup>
    59     *
    60     *    <tr><th> Function </th><th>  Hwi   </th><th>  Swi   </th><th>  Task  </th>
    61     *    <th>  Main  </th><th>  Startup  </th></tr>
    62     *    <!--                                                         -->
    63     *    <tr><td> {@link #Params_init} </td><td>   Y    </td><td>   Y    </td>
    64     *    <td>   Y    </td><td>   Y    </td><td>   Y    </td></tr>
    65     *    <tr><td> {@link #query}       </td><td>   Y    </td><td>   Y    </td>
    66     *    <td>   Y    </td><td>   Y    </td><td>   Y    </td></tr>
    67     *    <tr><td> {@link #construct}   </td><td>   Y    </td><td>   Y    </td>
    68     *    <td>   Y    </td><td>   Y    </td><td>   N    </td></tr>
    69     *    <tr><td> {@link #create}      </td><td>   N*   </td><td>   N*   </td>
    70     *    <td>   Y    </td><td>   Y    </td><td>   N    </td></tr>
    71     *    <tr><td> {@link #delete}      </td><td>   N*   </td><td>   N*   </td>
    72     *    <td>   Y    </td><td>   Y    </td><td>   N    </td></tr>
    73     *    <tr><td> {@link #destruct}    </td><td>   Y    </td><td>   Y    </td>
    74     *    <td>   Y    </td><td>   Y    </td><td>   N    </td></tr>
    75     *    <tr><td> {@link #enter}       </td><td>   Y    </td><td>   Y    </td>
    76     *    <td>   Y    </td><td>   Y**  </td><td>   Y**  </td></tr>
    77     *    <tr><td> {@link #leave}       </td><td>   Y    </td><td>   Y    </td>
    78     *    <td>   Y    </td><td>   Y**  </td><td>   Y**  </td></tr>
    79     *    <tr><td> {@link #sync}       </td><td>   Y    </td><td>   Y    </td>
    80     *    <td>   Y    </td><td>   Y**  </td><td>   Y**  </td></tr>
    81     *    <tr><td colspan="6"> Definitions: <br />
    82     *       <ul>
    83     *         <li> <b>Hwi</b>: API is callable from a Hwi thread. </li>
    84     *         <li> <b>Swi</b>: API is callable from a Swi thread. </li>
    85     *         <li> <b>Task</b>: API is callable from a Task thread. </li>
    86     *         <li> <b>Main</b>: API is callable during any of these phases: </li>
    87     *           <ul>
    88     *             <li> In your module startup after this module is started 
    89     *    (e.g. GateSmp_Module_startupDone() returns TRUE). </li>
    90     *             <li> During xdc.runtime.Startup.lastFxns. </li>
    91     *             <li> During main().</li>
    92     *             <li> During BIOS.startupFxns.</li>
    93     *           </ul>
    94     *         <li> <b>Startup</b>: API is callable during any of these phases:</li>
    95     *           <ul>
    96     *             <li> During xdc.runtime.Startup.firstFxns.</li>
    97     *             <li> In your module startup before this module is started 
    98     *    (e.g. GateSmp_Module_startupDone() returns FALSE).</li>
    99     *           </ul>
   100     *       <li> <b>*</b>:  Assuming blocking Heap is used for creation. </li>
   101     *       <li> <b>**</b>: Must be used in enter/leave pairs. </li>
   102     *       </ul>
   103     *    </td></tr>
   104     *
   105     *  </table>
   106     *  @p 
   107     */
   108    
   109    module GateSmp inherits xdc.runtime.IGateProvider
   110    {
   111    
   112        /*!
   113         *  ======== BasicView ========
   114         *  @_nodoc
   115         */
   116        metaonly struct BasicView {
   117            String  label;
   118            String      owner;
   119            String  gateValue;
   120            UInt    stalls;
   121            UInt    noStalls;
   122            UInt    totalStalls;
   123            UInt    maxStall;
   124        }
   125        
   126        /*!
   127         *  ======== rovViewInfo ========
   128         *  @_nodoc
   129         */
   130        @Facet
   131        metaonly config ViewInfo.Instance rovViewInfo = 
   132            ViewInfo.create({
   133                viewMap: [
   134                    ['Basic', {type: ViewInfo.INSTANCE, viewInitFxn: 'viewInitBasic', structName: 'BasicView'}],
   135                ]
   136            });
   137    
   138        /*! Assert if nested "enter" called. */
   139        config Assert.Id A_nestedEnter = {
   140            msg: "A_nestedEnter: Can't nest 'enter' calls."
   141        };
   142    
   143        /*! 
   144         *  Gate statistics collection flag. Default is disabled.
   145         */
   146        config bool enableStats = false;
   147    
   148    instance:
   149    
   150        /*!
   151         *  ======== enter ========
   152         *  Enter this gate
   153         *
   154         *  @a(constraints)
   155         *  Must be called with interrupts enabled
   156         */
   157        override IArg enter();
   158    
   159        /*!
   160         *  ======== leave ========
   161         *  Leave this gate
   162         *
   163         *  @a(constraints)
   164         *  Must be called with interrupts enabled
   165         */
   166        override Void leave(IArg key);
   167    
   168        /*!
   169         *  Sync execution with the other M3 core.
   170         */
   171        Void sync();
   172    
   173    internal:
   174    
   175    
   176        /* -------- Internal Structures -------- */
   177        struct Instance_State {
   178            volatile UInt32 gateWord;       /* byte/word addressable arbitor */
   179            volatile UInt   owner;
   180    
   181            /* below are for stats collection */
   182            UInt    stalls;
   183            UInt    noStalls;
   184            UInt    totalStalls;
   185            UInt    maxStall;
   186        };
   187    }