diff src/nucleus/pmc.c @ 0:4e78acac3d88

src/{condat,cs,gpf,nucleus}: import from Selenite
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 16 Oct 2020 06:23:26 +0000
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/nucleus/pmc.c	Fri Oct 16 06:23:26 2020 +0000
@@ -0,0 +1,889 @@
+/*************************************************************************/
+/*                                                                       */
+/*               Copyright Mentor Graphics Corporation 2002              */
+/*                         All Rights Reserved.                          */
+/*                                                                       */
+/* THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION WHICH IS  */
+/* THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS LICENSORS AND IS   */
+/* SUBJECT TO LICENSE TERMS.                                             */
+/*                                                                       */
+/*************************************************************************/
+
+/*************************************************************************/
+/*                                                                       */
+/* FILE NAME                                               VERSION       */
+/*                                                                       */
+/*      pmc.c                                          Nucleus PLUS 1.14 */
+/*                                                                       */
+/* COMPONENT                                                             */
+/*                                                                       */
+/*      PM - Partition Memory Management                                 */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This file contains the core routines for the Partition Memory    */
+/*      Management component.                                            */
+/*                                                                       */
+/* DATA STRUCTURES                                                       */
+/*                                                                       */
+/*      None                                                             */
+/*                                                                       */
+/* FUNCTIONS                                                             */
+/*                                                                       */
+/*      PMC_Create_Partition_Pool           Create a Partition Pool      */
+/*      PMC_Delete_Partition_Pool           Delete a Partition Pool      */
+/*      PMC_Allocate_Partition              Allocate a partition from a  */
+/*                                            pool                       */
+/*      PMC_Deallocate_Partition            Deallocate a partition from  */
+/*                                            a pool                     */
+/*      PMC_Cleanup                         Cleanup on timeout or a      */
+/*                                            terminate condition        */
+/*                                                                       */
+/* DEPENDENCIES                                                          */
+/*                                                                       */
+/*      cs_extr.h                           Common Service functions     */
+/*      tc_extr.h                           Thread Control functions     */
+/*      pm_extr.h                           Partition functions          */
+/*      hi_extr.h                           History functions            */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*         DATE                    REMARKS                               */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*      08-09-1993      Corrected pointer retrieval                      */
+/*                      loop, resulting in version 1.0a                  */
+/*      08-09-1993      Verified version 1.0a                            */
+/*      03-01-1994      Moved non-core functions into                    */
+/*                      supplemental files, changed                      */
+/*                      function interfaces to match                     */
+/*                      those in prototype, added                        */
+/*                      register options, changed                        */
+/*                      protection logic to reduce                       */
+/*                      overhead, resulting in                           */
+/*                      version 1.1                                      */
+/*                                                                       */
+/*      03-18-1994      Verified version 1.1                             */
+/*      04-17-1996      updated to version 1.2                           */
+/*      03-24-1998      Released version 1.3                             */
+/*      03-26-1999      Released 1.11m (new release                      */
+/*                        numbering scheme)                              */
+/*      04-17-2002      Released version 1.13m                           */
+/*      11-07-2002      Released version 1.14                            */
+/*************************************************************************/
+#define         NU_SOURCE_FILE
+
+
+#include        "cs_extr.h"                 /* Common service functions  */
+#include        "tc_extr.h"                 /* Thread control functions  */
+#include        "pm_extr.h"                 /* Partition functions       */
+#include        "hi_extr.h"                 /* History functions         */
+#include        "profiler.h"                /* ProView interface         */
+
+
+/* Define external inner-component global data references.  */
+
+extern CS_NODE         *PMD_Created_Pools_List;
+extern UNSIGNED         PMD_Total_Pools;
+extern TC_PROTECT       PMD_List_Protect;
+
+
+/* Define internal component function prototypes.  */
+
+VOID    PMC_Cleanup(VOID *information);
+
+
+/*************************************************************************/
+/*                                                                       */
+/* FUNCTION                                                              */
+/*                                                                       */
+/*      PMC_Create_Partition_Pool                                        */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This function creates a memory partition pool and then places it */
+/*      on the list of created partition pools.                          */
+/*                                                                       */
+/* CALLED BY                                                             */
+/*                                                                       */
+/*      Application                                                      */
+/*      PMCE_Create_Partition_Pool          Error checking shell         */
+/*                                                                       */
+/* CALLS                                                                 */
+/*                                                                       */
+/*      CSC_Place_On_List                   Add node to linked-list      */
+/*      [HIC_Make_History_Entry]            Make entry in history log    */
+/*      [TCT_Check_Stack]                   Stack checking function      */
+/*      TCT_Protect                         Data structure protect       */
+/*      TCT_Unprotect                       Un-protect data structure    */
+/*                                                                       */
+/* INPUTS                                                                */
+/*                                                                       */
+/*      pool_ptr                            Partition pool control block */
+/*                                            pointer                    */
+/*      name                                Partition pool name          */
+/*      start_address                       Starting address of the pool */
+/*      pool_size                           Number of bytes in the pool  */
+/*      partition_size                      Number of bytes in each      */
+/*                                            partition of the pool      */
+/*      suspend_type                        Suspension type              */
+/*                                                                       */
+/* OUTPUTS                                                               */
+/*                                                                       */
+/*      NU_SUCCESS                                                       */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*        DATE                    REMARKS                                */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*      03-01-1994      Changed function interfaces to                   */
+/*                      match those in prototype,                        */
+/*                      added register options,                          */
+/*                      resulting in version 1.1                         */
+/*                                                                       */
+/*      03-18-1994      Verified version 1.1                             */
+/*                                                                       */
+/*************************************************************************/
+STATUS  PMC_Create_Partition_Pool(NU_PARTITION_POOL *pool_ptr, CHAR *name,
+                        VOID *start_address, UNSIGNED pool_size,
+                        UNSIGNED partition_size, OPTION suspend_type)
+{
+
+R1 PM_PCB      *pool;                       /* Pool control block ptr    */
+INT             i;                          /* Working index variable    */
+BYTE_PTR        pointer;                    /* Working byte pointer      */
+PM_HEADER      *header_ptr;                 /* Partition block header ptr*/
+NU_SUPERV_USER_VARIABLES
+
+    /* Switch to supervisor mode */
+    NU_SUPERVISOR_MODE();
+
+    /* Move input pool pointer into internal pointer.  */
+    pool =  (PM_PCB *) pool_ptr;
+
+
+#ifdef  NU_ENABLE_STACK_CHECK
+
+    /* Call stack checking function to check for an overflow condition.  */
+    TCT_Check_Stack();
+
+#endif
+
+#ifdef  NU_ENABLE_HISTORY
+
+    /* Make an entry that corresponds to this function in the system history
+       log.  */
+    HIC_Make_History_Entry(NU_CREATE_PARTITION_POOL_ID, (UNSIGNED) pool,
+                                (UNSIGNED) name, (UNSIGNED) start_address);
+
+#endif
+
+    /* First, clear the partition pool ID just in case it is an old
+       pool control block.  */
+    pool -> pm_id =             0;
+
+    /* Fill in the partition pool name.  */
+    for (i = 0; i < NU_MAX_NAME; i++)
+        pool -> pm_name[i] =  name[i];
+
+    /* Save the starting address and size parameters in the partition control
+       block.  */
+    pool -> pm_start_address =   start_address;
+    pool -> pm_pool_size =       pool_size;
+    pool -> pm_partition_size =  partition_size;
+
+    /* Setup the partition pool suspension type.  */
+    if (suspend_type == NU_FIFO)
+
+        /* FIFO suspension is selected, setup the flag accordingly.  */
+        pool -> pm_fifo_suspend =  NU_TRUE;
+    else
+
+        /* Priority suspension is selected.  */
+        pool -> pm_fifo_suspend =  NU_FALSE;
+
+    /* Clear the suspension list pointer.  */
+    pool -> pm_suspension_list =  NU_NULL;
+
+    /* Clear the number of tasks waiting on the partition pool.  */
+    pool -> pm_tasks_waiting =  0;
+
+    /* Initialize link pointers.  */
+    pool -> pm_created.cs_previous =    NU_NULL;
+    pool -> pm_created.cs_next =        NU_NULL;
+
+    /* Initialize the partition parameters.  */
+    pool -> pm_available =       0;
+    pool -> pm_allocated =       0;
+    pool -> pm_available_list =  NU_NULL;
+
+    /* Convert the supplied partition size into something that is evenly
+       divisible by the sizeof an UNSIGNED data element.  This insures
+       UNSIGNED alignment.  */
+    partition_size =
+        ((partition_size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) *
+                                                        sizeof(UNSIGNED);
+
+    /* Loop to build and link as many partitions as possible from within the
+       specified memory area.  */
+    pointer =  (BYTE_PTR)  start_address;
+    while (pool_size >= (PM_OVERHEAD + partition_size))
+    {
+
+        /* There is room for another partition.  */
+
+        /* Cast the current pointer variable to a header pointer.  */
+        header_ptr =  (PM_HEADER *) pointer;
+
+        /* Now, build a header and link it into the partition pool
+           available list- at the front.  */
+        header_ptr -> pm_partition_pool =  pool;
+        header_ptr -> pm_next_available =  pool -> pm_available_list;
+        pool -> pm_available_list =        header_ptr;
+
+        /* Increment the number of partitions available in the pool.  */
+        pool -> pm_available++;
+
+        /* Decrement the number of bytes remaining in the pool.  */
+        pool_size =  pool_size - (PM_OVERHEAD + partition_size);
+
+        /* Increment the working pointer to the next partition position.  */
+        pointer =  pointer + (PM_OVERHEAD + partition_size);
+    }
+
+    /* Protect against access to the list of created partition pools.  */
+    TCT_Protect(&PMD_List_Protect);
+
+    /* At this point the partition pool is completely built.  The ID can
+       now be set and it can be linked into the created partition pool list. */
+    pool -> pm_id =  PM_PARTITION_ID;
+
+    /* Link the partition pool into the list of created partition pools and
+       increment the total number of pools in the system.  */
+    CSC_Place_On_List(&PMD_Created_Pools_List, &(pool -> pm_created));
+    PMD_Total_Pools++;
+
+#ifdef INCLUDE_PROVIEW
+    _RTProf_DumpPartitionPool(RT_PROF_CREATE_PARTITION_POOL,pool,RT_PROF_OK);
+#endif /* INCLUDE_PROVIEW */
+    /* Release protection against access to the list of created partition
+       pools.  */
+    TCT_Unprotect();
+
+    /* Return to user mode */
+    NU_USER_MODE();
+
+    /* Return successful completion.  */
+    return(NU_SUCCESS);
+}
+
+
+/*************************************************************************/
+/*                                                                       */
+/* FUNCTION                                                              */
+/*                                                                       */
+/*      PMC_Delete_Partition_Pool                                        */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This function deletes a memory partition pool and removes it from*/
+/*      the list of created partition pools.  All tasks suspended on the */
+/*      partition pool are resumed with the appropriate error status.    */
+/*      Note that this function does not free any memory associated with */
+/*      either the pool area or the pool control block.                  */
+/*                                                                       */
+/* CALLED BY                                                             */
+/*                                                                       */
+/*      Application                                                      */
+/*      PMCE_Delete_Partition_Pool          Error checking shell         */
+/*                                                                       */
+/* CALLS                                                                 */
+/*                                                                       */
+/*      CSC_Remove_From_List                Remove node from list        */
+/*      [HIC_Make_History_Entry]            Make entry in history log    */
+/*      TCC_Resume_Task                     Resume a suspended task      */
+/*      [TCT_Check_Stack]                   Stack checking function      */
+/*      TCT_Control_To_System               Transfer control to system   */
+/*      TCT_Protect                         Protect created list         */
+/*      TCT_Set_Current_Protect             Modify current protection    */
+/*      TCT_System_Protect                  Setup system protection      */
+/*      TCT_System_Unprotect                Release system protection    */
+/*      TCT_Unprotect                       Release protection           */
+/*                                                                       */
+/* INPUTS                                                                */
+/*                                                                       */
+/*      pool_ptr                            Partition pool control block */
+/*                                            pointer                    */
+/*                                                                       */
+/* OUTPUTS                                                               */
+/*                                                                       */
+/*      NU_SUCCESS                                                       */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*         DATE                    REMARKS                               */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*      03-01-1994      Changed function interfaces to                   */
+/*                      match those in prototype,                        */
+/*                      added register options, changed                  */
+/*                      protection logic to reduce                       */
+/*                      overhead, resulting in                           */
+/*                      version 1.1                                      */
+/*                                                                       */
+/*      03-18-1994      Verified version 1.1                             */
+/*                                                                       */
+/*************************************************************************/
+STATUS  PMC_Delete_Partition_Pool(NU_PARTITION_POOL *pool_ptr)
+{
+
+R1 PM_PCB      *pool;                       /* Pool control block ptr    */
+PM_SUSPEND     *suspend_ptr;                /* Suspend block pointer     */
+PM_SUSPEND     *next_ptr;                   /* Next suspend block        */
+STATUS          preempt;                    /* Status for resume call    */
+NU_SUPERV_USER_VARIABLES
+
+    /* Switch to supervisor mode */
+    NU_SUPERVISOR_MODE();
+
+    /* Move input pool pointer into internal pointer.  */
+    pool =  (PM_PCB *) pool_ptr;
+
+
+#ifdef  NU_ENABLE_STACK_CHECK
+
+    /* Call stack checking function to check for an overflow condition.  */
+    TCT_Check_Stack();
+
+#endif
+
+#ifdef  NU_ENABLE_HISTORY
+
+    /* Make an entry that corresponds to this function in the system history
+       log.  */
+    HIC_Make_History_Entry(NU_DELETE_PARTITION_POOL_ID, (UNSIGNED) pool,
+                                        (UNSIGNED) 0, (UNSIGNED) 0);
+
+#endif
+
+    /* Protect against simultaneous access to the partition pool.  */
+    TCT_System_Protect();
+
+#ifdef INCLUDE_PROVIEW
+    _RTProf_DumpPartitionPool(RT_PROF_DELETE_PARTITION_POOL,pool,RT_PROF_OK);
+#endif /* INCLUDE_PROVIEW */
+
+    /* Clear the partition pool ID.  */
+    pool -> pm_id =  0;
+
+    /* Release protection.  */
+    TCT_Unprotect();
+
+    /* Protect against access to the list of created partition pools.  */
+    TCT_Protect(&PMD_List_Protect);
+
+    /* Remove the partition pool from the list of created partition pools.  */
+    CSC_Remove_From_List(&PMD_Created_Pools_List, &(pool -> pm_created));
+
+    /* Decrement the total number of created partition pools.  */
+    PMD_Total_Pools--;
+
+    /* Pickup the suspended task pointer list.  */
+    suspend_ptr =  pool -> pm_suspension_list;
+
+    /* Walk the chain task(s) currently suspended on the partition pool.  */
+    preempt =  0;
+    while (suspend_ptr)
+    {
+
+        /* Protect against system access.  */
+        TCT_System_Protect();
+
+        /* Resume the suspended task.  Insure that the status returned is
+           NU_POOL_DELETED.  */
+        suspend_ptr -> pm_return_pointer =  NU_NULL;
+        suspend_ptr -> pm_return_status =   NU_POOL_DELETED;
+
+        /* Point to the next suspend structure in the link.  */
+        next_ptr =  (PM_SUSPEND *) (suspend_ptr -> pm_suspend_link.cs_next);
+
+        /* Resume the specified task.  */
+        preempt =  preempt |
+            TCC_Resume_Task((NU_TASK *) suspend_ptr -> pm_suspended_task,
+                                                NU_PARTITION_SUSPEND);
+
+        /* Determine if the next is the same as the current pointer.  */
+        if (next_ptr == pool -> pm_suspension_list)
+
+            /* Clear the suspension pointer to signal the end of the list
+               traversal.  */
+            suspend_ptr =  NU_NULL;
+        else
+
+            /* Move the next pointer into the suspend block pointer.  */
+            suspend_ptr =  next_ptr;
+
+        /* Modify current protection.  */
+        TCT_Set_Current_Protect(&PMD_List_Protect);
+
+        /* Clear the system protection.  */
+        TCT_System_Unprotect();
+    }
+
+    /* Determine if preemption needs to occur.  */
+    if (preempt)
+
+        /* Transfer control to system to facilitate preemption.  */
+        TCT_Control_To_System();
+
+    /* Release protection against access to the list of created partition
+       pools. */
+    TCT_Unprotect();
+
+    /* Return to user mode */
+    NU_USER_MODE();
+
+    /* Return a successful completion.  */
+    return(NU_SUCCESS);
+}
+
+
+/*************************************************************************/
+/*                                                                       */
+/* FUNCTION                                                              */
+/*                                                                       */
+/*      PMC_Allocate_Partition                                           */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This function allocates a memory partition from the specified    */
+/*      memory partition pool.  If a memory partition is currently       */
+/*      available, this function is completed immediately.  Otherwise,   */
+/*      if there are no partitions currently available, suspension is    */
+/*      possible.                                                        */
+/*                                                                       */
+/* CALLED BY                                                             */
+/*                                                                       */
+/*      Application                                                      */
+/*      PMCE_Allocate_Partition             Error checking shell         */
+/*                                                                       */
+/* CALLS                                                                 */
+/*                                                                       */
+/*      CSC_Place_On_List                   Place on suspend list        */
+/*      CSC_Priority_Place_On_List          Place on priority list       */
+/*      [HIC_Make_History_Entry]            Make entry in history log    */
+/*      TCC_Suspend_Task                    Suspend calling task         */
+/*      TCC_Task_Priority                   Pickup task's priority       */
+/*      [TCT_Check_Stack]                   Stack checking function      */
+/*      TCT_Current_Thread                  Pickup current thread pointer*/
+/*      TCT_System_Protect                  Protect partition pool       */
+/*      TCT_Unprotect                       Release protection           */
+/*                                                                       */
+/* INPUTS                                                                */
+/*                                                                       */
+/*      pool_ptr                            Memory partition pool pointer*/
+/*      return_pointer                      Pointer to the destination   */
+/*                                            memory pointer             */
+/*      suspend                             Suspension option if full    */
+/*                                                                       */
+/* OUTPUTS                                                               */
+/*                                                                       */
+/*      NU_SUCCESS                          If service is successful     */
+/*      NU_NO_PARTITION                     No partitions are available  */
+/*      NU_TIMEOUT                          If timeout on service        */
+/*      NU_POOL_DELETED                     If partition pool deleted    */
+/*                                            during suspension          */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*        DATE                    REMARKS                                */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*      03-01-1994      Changed function interfaces to                   */
+/*                      match those in prototype,                        */
+/*                      added register options, changed                  */
+/*                      protection logic to reduce                       */
+/*                      overhead, resulting in                           */
+/*                      version 1.1                                      */
+/*                                                                       */
+/*      03-18-1994      Verified version 1.1                             */
+/*                                                                       */
+/*************************************************************************/
+STATUS  PMC_Allocate_Partition(NU_PARTITION_POOL *pool_ptr,
+                                VOID **return_pointer, UNSIGNED suspend)
+{
+
+R1 PM_PCB      *pool;                       /* Pool control block ptr    */
+R2 PM_SUSPEND  *suspend_ptr;                /* Suspend block pointer     */
+PM_SUSPEND      suspend_block;              /* Allocate suspension block */
+R3 PM_HEADER   *partition_ptr;              /* Pointer to partition      */
+TC_TCB         *task;                       /* Task pointer              */
+STATUS          status;                     /* Completion status         */
+NU_SUPERV_USER_VARIABLES
+
+    /* Switch to supervisor mode */
+    NU_SUPERVISOR_MODE();
+
+    /* Move input pool pointer into internal pointer.  */
+    pool =  (PM_PCB *) pool_ptr;
+
+
+#ifdef  NU_ENABLE_STACK_CHECK
+
+    /* Call stack checking function to check for an overflow condition.  */
+    TCT_Check_Stack();
+
+#endif
+
+#ifdef  NU_ENABLE_HISTORY
+
+    /* Make an entry that corresponds to this function in the system history
+       log.  */
+    HIC_Make_History_Entry(NU_ALLOCATE_PARTITION_ID, (UNSIGNED) pool,
+                                (UNSIGNED) return_pointer, (UNSIGNED) suspend);
+
+#endif
+
+    /* Initialize the status as successful.  */
+    status =  NU_SUCCESS;
+
+    /* Protect against simultaneous access to the partition pool.  */
+    TCT_System_Protect();
+
+    /* Determine if there is an available memory partition.  */
+    if (pool -> pm_available)
+    {
+
+        /* Partition available.  */
+
+        /* Decrement the available count.  */
+        pool -> pm_available--;
+
+        /* Increment the allocated count.  */
+        pool -> pm_allocated++;
+
+        /* Unlink the first memory partition and return the pointer to the
+           caller.  */
+        partition_ptr =              pool -> pm_available_list;
+        pool -> pm_available_list =  partition_ptr -> pm_next_available;
+        partition_ptr -> pm_next_available =  NU_NULL;
+
+        /* Return a memory address to the caller.  */
+        *return_pointer =  (VOID *) (((BYTE_PTR) partition_ptr) + PM_OVERHEAD);
+
+#ifdef INCLUDE_PROVIEW
+        _RTProf_DumpPartitionPool(RT_PROF_ALLOCATE_PARTITION,pool,RT_PROF_OK);
+#endif /* INCLUDE_PROVIEW */
+
+    }
+    else
+    {
+
+        /* A partition is not available.  Determine if suspension is
+           required. */
+        if (suspend)
+        {
+
+            /* Suspension is selected.  */
+
+            /* Increment the number of tasks waiting.  */
+            pool -> pm_tasks_waiting++;
+
+#ifdef INCLUDE_PROVIEW
+            _RTProf_DumpPartitionPool(RT_PROF_ALLOCATE_PARTITION,pool,RT_PROF_WAIT);
+#endif /* INCLUDE_PROVIEW */
+            /* Setup the suspend block and suspend the calling task.  */
+            suspend_ptr =  &suspend_block;
+            suspend_ptr -> pm_partition_pool =           pool;
+            suspend_ptr -> pm_suspend_link.cs_next =     NU_NULL;
+            suspend_ptr -> pm_suspend_link.cs_previous = NU_NULL;
+            task =                            (TC_TCB *) TCT_Current_Thread();
+            suspend_ptr -> pm_suspended_task =           task;
+
+            /* Determine if priority or FIFO suspension is associated with the
+               partition pool.  */
+            if (pool -> pm_fifo_suspend)
+            {
+
+                /* FIFO suspension is required.  Link the suspend block into
+                   the list of suspended tasks on this partition pool.  */
+                CSC_Place_On_List((CS_NODE **)
+                        &(pool -> pm_suspension_list),
+                                        &(suspend_ptr -> pm_suspend_link));
+            }
+            else
+            {
+
+                /* Get the priority of the current thread so the suspend block
+                   can be placed in the appropriate place.  */
+                suspend_ptr -> pm_suspend_link.cs_priority =
+                                                     TCC_Task_Priority(task);
+
+                CSC_Priority_Place_On_List((CS_NODE **)
+                        &(pool -> pm_suspension_list),
+                                        &(suspend_ptr -> pm_suspend_link));
+            }
+
+            /* Finally, suspend the calling task. Note that the suspension call
+               automatically clears the protection on the partition pool.  */
+            TCC_Suspend_Task((NU_TASK *) task, NU_PARTITION_SUSPEND,
+                                        PMC_Cleanup, suspend_ptr, suspend);
+
+            /* Pickup the return status.  */
+            status =            suspend_ptr -> pm_return_status;
+            *return_pointer =   suspend_ptr -> pm_return_pointer;
+        }
+        else
+        {
+            /* No suspension requested.  Simply return an error status.  */
+            status =  NU_NO_PARTITION;
+
+#ifdef INCLUDE_PROVIEW
+            _RTProf_DumpPartitionPool(RT_PROF_ALLOCATE_PARTITION,pool,RT_PROF_FAIL);
+#endif /* INCLUDE_PROVIEW */
+        }
+    }
+
+    /* Release protection of the partition pool.  */
+    TCT_Unprotect();
+
+    /* Return to user mode */
+    NU_USER_MODE();
+
+    /* Return the completion status.  */
+    return(status);
+}
+
+
+/*************************************************************************/
+/*                                                                       */
+/* FUNCTION                                                              */
+/*                                                                       */
+/*      PMC_Deallocate_Partition                                         */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This function deallocates a previously allocated partition.  If  */
+/*      there is a task waiting for a partition, the partition is simply */
+/*      given to the waiting task and the waiting task is resumed.       */
+/*      Otherwise, the partition is returned to the partition pool.      */
+/*                                                                       */
+/* CALLED BY                                                             */
+/*                                                                       */
+/*      Application                                                      */
+/*      PMCE_Deallocate_Partition           Error checking shell         */
+/*                                                                       */
+/* CALLS                                                                 */
+/*                                                                       */
+/*      CSC_Remove_From_List                Remove from suspend list     */
+/*      [HIC_Make_History_Entry]            Make entry in history log    */
+/*      TCC_Resume_Task                     Resume a suspended task      */
+/*      [TCT_Check_Stack]                   Stack checking function      */
+/*      TCT_Control_To_System               Transfer control to system   */
+/*      TCT_System_Protect                  Protect partition pool       */
+/*      TCT_Unprotect                       Release protection           */
+/*                                                                       */
+/* INPUTS                                                                */
+/*                                                                       */
+/*      partition                           Pointer to partition memory  */
+/*                                                                       */
+/* OUTPUTS                                                               */
+/*                                                                       */
+/*      NU_SUCCESS                                                       */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*        DATE                    REMARKS                                */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*      03-01-1994      Added register options, changed                  */
+/*                      protection logic to reduce                       */
+/*                      overhead, resulting in                           */
+/*                      version 1.1                                      */
+/*                                                                       */
+/*      03-18-1994      Verified version 1.1                             */
+/*                                                                       */
+/*************************************************************************/
+STATUS  PMC_Deallocate_Partition(VOID *partition)
+{
+
+R1 PM_PCB      *pool;                       /* Pool pointer              */
+R3 PM_SUSPEND  *suspend_ptr;                /* Pointer to suspend block  */
+R2 PM_HEADER   *header_ptr;                 /* Pointer to partition hdr  */
+STATUS          preempt;                    /* Preemption flag           */
+STATUS          status;                     /* Completion status         */
+NU_SUPERV_USER_VARIABLES
+
+    /* Switch to supervisor mode */
+    NU_SUPERVISOR_MODE();
+
+#ifdef  NU_ENABLE_STACK_CHECK
+
+    /* Call stack checking function to check for an overflow condition.  */
+    TCT_Check_Stack();
+
+#endif
+
+#ifdef  NU_ENABLE_HISTORY
+
+    /* Make an entry that corresponds to this function in the system history
+       log.  */
+    HIC_Make_History_Entry(NU_DEALLOCATE_PARTITION_ID, (UNSIGNED) partition,
+                                        (UNSIGNED) 0, (UNSIGNED) 0);
+
+#endif
+
+    /* Initialize the status as successful.  */
+    status =  NU_SUCCESS;
+
+    /* Pickup the associated pool's pointer.  It is inside the header of
+       each partition.  */
+    header_ptr =  (PM_HEADER *) (((BYTE_PTR) partition) - PM_OVERHEAD);
+    pool =        header_ptr -> pm_partition_pool;
+
+    /* Protect against simultaneous access to the partition pool.  */
+    TCT_System_Protect();
+
+    /* Determine if another task is waiting for a partition from the pool.  */
+    if (pool -> pm_tasks_waiting)
+    {
+
+        /* Yes, another task is waiting for a partition from the pool.  */
+
+        /* Decrement the number of tasks waiting counter.  */
+        pool -> pm_tasks_waiting--;
+
+#ifdef INCLUDE_PROVIEW
+    _RTProf_DumpPartitionPool(RT_PROF_DEALLOCATE_PARTITION,pool,RT_PROF_OK);
+#endif /* INCLUDE_PROVIEW */
+
+        /* Remove the first suspended block from the list.  */
+        suspend_ptr =  pool -> pm_suspension_list;
+        CSC_Remove_From_List((CS_NODE **) &(pool -> pm_suspension_list),
+                                &(suspend_ptr -> pm_suspend_link));
+
+        /* Setup the appropriate return value.  */
+        suspend_ptr -> pm_return_status =   NU_SUCCESS;
+        suspend_ptr -> pm_return_pointer =  partition;
+
+        /* Resume the suspended task.  */
+        preempt =
+           TCC_Resume_Task((NU_TASK *) suspend_ptr -> pm_suspended_task,
+                                                       NU_PARTITION_SUSPEND);
+
+        /* Determine if a preempt condition is present.  */
+        if (preempt)
+
+            /* Transfer control to the system if the resumed task function
+               detects a preemption condition.  */
+            TCT_Control_To_System();
+    }
+    else
+    {
+
+        /* Increment the available partitions counter.  */
+        pool -> pm_available++;
+
+        /* Decrement the allocated partitions counter.  */
+        pool -> pm_allocated--;
+
+        /* Place the partition back on the available list.  */
+        header_ptr -> pm_next_available =  pool -> pm_available_list;
+        pool -> pm_available_list =        header_ptr;
+
+#ifdef INCLUDE_PROVIEW
+    _RTProf_DumpPartitionPool(RT_PROF_DEALLOCATE_PARTITION,pool,RT_PROF_OK);
+#endif /* INCLUDE_PROVIEW */
+
+    }
+
+    /* Release protection of the partition pool.  */
+    TCT_Unprotect();
+
+    /* Return to user mode */
+    NU_USER_MODE();
+
+    /* Return the completion status.  */
+    return(status);
+}
+
+
+/*************************************************************************/
+/*                                                                       */
+/* FUNCTION                                                              */
+/*                                                                       */
+/*      PMC_Cleanup                                                      */
+/*                                                                       */
+/* DESCRIPTION                                                           */
+/*                                                                       */
+/*      This function is responsible for removing a suspension block     */
+/*      from a partition pool.  It is not called unless a timeout or     */
+/*      a task terminate is in progress.  Note that protection is        */
+/*      already in effect - the same protection at suspension time.      */
+/*                                                                       */
+/* CALLED BY                                                             */
+/*                                                                       */
+/*      TCC_Timeout                         Task timeout                 */
+/*      TCC_Terminate                       Task terminate               */
+/*                                                                       */
+/* CALLS                                                                 */
+/*                                                                       */
+/*      CSC_Remove_From_List                Remove suspend block from    */
+/*                                            the suspension list        */
+/*                                                                       */
+/* INPUTS                                                                */
+/*                                                                       */
+/*      information                         Pointer to suspend block     */
+/*                                                                       */
+/* OUTPUTS                                                               */
+/*                                                                       */
+/*      None                                                             */
+/*                                                                       */
+/* HISTORY                                                               */
+/*                                                                       */
+/*         DATE                    REMARKS                               */
+/*                                                                       */
+/*      03-01-1993      Created initial version 1.0                      */
+/*      04-19-1993      Verified version 1.0                             */
+/*                                                                       */
+/*************************************************************************/
+VOID  PMC_Cleanup(VOID *information)
+{
+
+PM_SUSPEND      *suspend_ptr;               /* Suspension block pointer  */
+NU_SUPERV_USER_VARIABLES
+
+    /* Switch to supervisor mode */
+    NU_SUPERVISOR_MODE();
+
+    /* Use the information pointer as a suspend pointer.  */
+    suspend_ptr =  (PM_SUSPEND *) information;
+
+    /* By default, indicate that the service timed-out.  It really does not
+       matter if this function is called from a terminate request since
+       the task does not resume.  */
+    suspend_ptr -> pm_return_status =   NU_TIMEOUT;
+    suspend_ptr -> pm_return_pointer =  NU_NULL;
+
+    /* Decrement the number of tasks waiting counter.  */
+    (suspend_ptr -> pm_partition_pool) -> pm_tasks_waiting--;
+
+    /* Unlink the suspend block from the suspension list.  */
+    CSC_Remove_From_List((CS_NODE **)
+                &((suspend_ptr -> pm_partition_pool) -> pm_suspension_list),
+                                &(suspend_ptr -> pm_suspend_link));
+
+    /* Return to user mode */
+    NU_USER_MODE();
+}
+
+
+
+
+