1 | /* SPDX-License-Identifier: BSD-2-Clause */ |
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2 | |
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3 | /* Shared Memory Lock Routines |
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4 | * |
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5 | * This shared memory locked queue support routine need to be |
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6 | * able to lock the specified locked queue. Interrupts are |
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7 | * disabled while the queue is locked to prevent preemption |
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8 | * and deadlock when two tasks poll for the same lock. |
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9 | * previous level. |
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10 | * |
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11 | * COPYRIGHT (c) 1989-2008. |
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12 | * On-Line Applications Research Corporation (OAR). |
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13 | * |
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14 | * Redistribution and use in source and binary forms, with or without |
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15 | * modification, are permitted provided that the following conditions |
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16 | * are met: |
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17 | * 1. Redistributions of source code must retain the above copyright |
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18 | * notice, this list of conditions and the following disclaimer. |
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19 | * 2. Redistributions in binary form must reproduce the above copyright |
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20 | * notice, this list of conditions and the following disclaimer in the |
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21 | * documentation and/or other materials provided with the distribution. |
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22 | * |
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23 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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24 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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25 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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26 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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27 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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28 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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29 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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30 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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31 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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32 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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33 | * POSSIBILITY OF SUCH DAMAGE. |
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34 | */ |
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35 | |
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36 | #include <rtems.h> |
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37 | #include <bsp.h> |
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38 | #include <shm_driver.h> |
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39 | #include <psim.h> |
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40 | |
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41 | /* |
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42 | * Shm_Initialize_lock |
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43 | * |
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44 | * Initialize the lock for the specified locked queue. |
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45 | */ |
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46 | |
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47 | void Shm_Initialize_lock( |
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48 | Shm_Locked_queue_Control *lq_cb |
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49 | ) |
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50 | { |
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51 | /* nothing required -- done implicitly by device tree */ |
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52 | } |
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53 | |
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54 | /* void _Shm_Lock( &lq_cb ) |
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55 | * |
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56 | * This shared memory locked queue support routine locks the |
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57 | * specified locked queue. It disables interrupts to prevent |
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58 | * a deadlock condition. |
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59 | */ |
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60 | |
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61 | static rtems_interrupt_level level; |
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62 | |
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63 | void Shm_Lock( |
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64 | Shm_Locked_queue_Control *lq_cb |
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65 | ) |
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66 | { |
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67 | rtems_interrupt_disable( level ); |
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68 | (void) PSIM.Semaphore.lock; |
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69 | } |
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70 | |
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71 | /* |
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72 | * Shm_Unlock |
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73 | * |
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74 | * Unlock the lock for the specified locked queue. |
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75 | */ |
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76 | |
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77 | void Shm_Unlock( |
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78 | Shm_Locked_queue_Control *lq_cb |
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79 | ) |
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80 | { |
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81 | (void) PSIM.Semaphore.unlock; |
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82 | rtems_interrupt_enable( level ); |
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83 | } |
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