text: /****************************************************************************
   * arch/z80/src/common/z80_createstack.c
   *
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.  The
   * ASF licenses this file to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance with the
   * License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
   * License for the specific language governing permissions and limitations
   * under the License.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <sys/types.h>
  #include <stdint.h>
  #include <sched.h>
  #include <debug.h>
  
  #include <nuttx/kmalloc.h>
  #include <nuttx/arch.h>
  #include <nuttx/tls.h>
  #include <nuttx/board.h>
  
  #include "z80_arch.h"
  #include "z80_internal.h"
  
  /****************************************************************************
   * Private Types
   ****************************************************************************/
  
  /****************************************************************************
   * Private Function Prototypes
   ****************************************************************************/
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: up_create_stack
   *
   * Description:
   *   Allocate a stack for a new thread and setup up stack-related information
   *   in the TCB.
   *
   *   The following TCB fields must be initialized by this function:
   *
   *   - adj_stack_size: Stack size after adjustment for hardware, processor,
   *     etc.  This value is retained only for debug purposes.
   *   - stack_alloc_ptr: Pointer to allocated stack
   *   - adj_stack_ptr: Adjusted stack_alloc_ptr for HW.  The initial value of
   *     the stack pointer.
   *
   * Input Parameters:
   *   - tcb: The TCB of new task
   *   - stack_size:  The requested stack size.  At least this much
   *     must be allocated.
   *   - ttype:  The thread type.  This may be one of following (defined in
   *     include/nuttx/sched.h):
   *
   *       TCB_FLAG_TTYPE_TASK     Normal user task
   *       TCB_FLAG_TTYPE_PTHREAD  User pthread
   *       TCB_FLAG_TTYPE_KERNEL   Kernel thread
   *
   *     This thread type is normally available in the flags field of the TCB,
   *     however, there are certain contexts where the TCB may not be fully
   *     initialized when up_create_stack is called.
   *
   *     If CONFIG_BUILD_KERNEL is defined, then this thread type may affect
   *     how the stack is allocated.  For example, kernel thread stacks should
   *     be allocated from protected kernel memory.  Stacks for user tasks and
   *     threads must come from memory that is accessible to user code.
   *
   ****************************************************************************/
  
  int up_create_stack(FAR struct tcb_s *tcb, size_t stack_size, uint8_t ttype)
  {
    /* Add the size of the TLS information structure */
  
    stack_size += sizeof(struct tls_info_s);
  
  #ifdef CONFIG_TLS_ALIGNED
    /* The allocated stack size must not exceed the maximum possible for the
     * TLS feature.
     */
  
    DEBUGASSERT(stack_size <= TLS_MAXSTACK);
    if (stack_size >= TLS_MAXSTACK)
      {
        stack_size = TLS_MAXSTACK;
      }
  #endif
  
    /* Is there already a stack allocated of a different size?  Because of
     * alignment issues, stack_size might erroneously appear to be of a
     * different size.  Fortunately, this is not a critical operation.
     */
  
    if (tcb->stack_alloc_ptr && tcb->adj_stack_size != stack_size)
      {
        /* Yes.. Release the old stack */
  
        up_release_stack(tcb, ttype);
      }
  
    /* Do we need to allocate a new stack? */
  
    if (!tcb->stack_alloc_ptr)
      {
        /* Allocate the stack.  If DEBUG is enabled (but not stack debug),
         * then create a zeroed stack to make stack dumps easier to trace.
         * If TLS is enabled, then we must allocate aligned stacks.
         */
  
  #ifdef CONFIG_TLS_ALIGNED
  #ifdef CONFIG_MM_KERNEL_HEAP
        /* Use the kernel allocator if this is a kernel thread */
  
        if (ttype == TCB_FLAG_TTYPE_KERNEL)
          {
            tcb->stack_alloc_ptr =
              (uint32_t *)kmm_memalign(TLS_STACK_ALIGN, stack_size);
          }
        else
  #endif
          {
            /* Use the user-space allocator if this is a task or pthread */
  
            tcb->stack_alloc_ptr =
              (uint32_t *)kumm_memalign(TLS_STACK_ALIGN, stack_size);
          }
  
  #else /* CONFIG_TLS_ALIGNED */
  #ifdef CONFIG_MM_KERNEL_HEAP
        /* Use the kernel allocator if this is a kernel thread */
  
        if (ttype == TCB_FLAG_TTYPE_KERNEL)
          {
            tcb->stack_alloc_ptr = (uint32_t *)kmm_malloc(stack_size);
          }
        else
  #endif
          {
            /* Use the user-space allocator if this is a task or pthread */
  
            tcb->stack_alloc_ptr = (uint32_t *)kumm_malloc(stack_size);
          }
  #endif /* CONFIG_TLS_ALIGNED */
  
  #ifdef CONFIG_DEBUG_FEATURES
        /* Was the allocation successful? */
  
        if (!tcb->stack_alloc_ptr)
          {
            serr("ERROR: Failed to allocate stack, size %d\n", stack_size);
          }
  #endif
      }
  
    /* Did we successfully allocate a stack? */
  
    if (tcb->stack_alloc_ptr)
      {
        size_t top_of_stack;
        size_t size_of_stack;
  
        /* Yes.. If stack debug is enabled, then fill the stack with a
         * recognizable value that we can use later to test for high
         * water marks.
         */
  
  #ifdef CONFIG_STACK_COLORATION
        memset(tcb->stack_alloc_ptr, 0xaa, stack_size);
  #endif
  
        /* The Z80 family uses a push-down stack:  the stack grows
         * toward loweraddresses in memory.  The stack pointer
         * register, points to the lowest, valid work address
         * (the "top" of the stack).  Items on the stack are
         * referenced as positive word offsets from sp.
         */
  
        top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size;
  
        /* The Z80 stack does not need to be aligned.  Here is is aligned at
         * word (4 byte) boundary.
         */
  
        top_of_stack &= ~3;
        size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr;
  
        /* Save the adjusted stack values in the struct tcb_s */
  
        tcb->adj_stack_ptr  = (FAR uint32_t *)top_of_stack;
        tcb->adj_stack_size = size_of_stack;
  
        /* Initialize the TLS data structure */
  
        memset(tcb->stack_alloc_ptr, 0, sizeof(struct tls_info_s));
  
        board_autoled_on(LED_STACKCREATED);
        return OK;
      }
  
    return ERROR;
  }
  