nuttx/arch/z80/src/common/z80_createstack.c

/****************************************************************************
 * 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 - 4;

      /* 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 + 4;

      /* 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;
}