nuttx/configs/ea3131/src/up_fillpage.c

/****************************************************************************
 * configs/ea3131/src/up_fillpage.c
 * arch/arm/src/board/up_fillpage.c
 *
 *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <errno.h>
#include <debug.h>

#include <nuttx/sched.h>
#include <nuttx/page.h>

#ifdef CONFIG_PAGING

/****************************************************************************
 * Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

 /****************************************************************************
 * Name: up_fillpage()
 *
 * Description:
 *  After a page is allocated and mapped by up_allocpage(), the actual
 *  filling of the page with data from the non-volatile, must be performed
 *  by a separate call to the architecture-specific function, up_fillpage().
 *  This function is non-blocking, it will start an asynchronous page fill.
 *  The common paging logic will provide a callback function, pg_callback,
 *  that will be called when the page fill is finished (or an error occurs).
 *  This callback is assumed to occur from an interrupt level when the
 *  device driver completes the fill operation.
 *
 *  NOTE 1: Allocating and filling a page is a two step process.  up_allocpage()
 *  allocates the page, and up_fillpage() fills it with data from some non-
 *  volatile storage device.  This distinction is made because up_allocpage()
 *  can probably be implemented in board-independent logic whereas up_fillpage()
 *  probably must be implemented as board-specific logic.
 *
 *  NOTE 2: The initial mapping of vpage will be read-able, write-able,
 *  but non-cacheable.  No special actions will be required of
 *  up_fillpage() in order to write into this allocated page.  If the
 *  virtual address maps to a text region, however, this function should
 *  remap the region so that is is read/execute only.  It should be made
 *  cache-able in any case.

 * Input Parameters:
 *   tcb - A reference to the task control block of the task that needs to
 *         have a page fill.  Architecture-specific logic can retrieve page
 *         fault information from the architecture-specific context
 *         information in this TCB to perform the fill.
 *   pg_callbck - The function to be called when the page fill is complete.
 *
 * Returned Value:
 *   This function will return zero (OK) if the page fill was successfully
 *   started (the result of the page fill is passed to the callback function
 *   as the result argument).  A negated errno value may be returned if an
 *   error occurs.  All errors, however, are fatal.
 *
 *   NOTE: -EBUSY has a special meaning. It is used internally to mean that
 *   the callback function has not executed.  Therefore, -EBUSY should
 *   never be provided in the result argument of pg_callback.
 *
 * Assumptions:
 *   - This function is called from the normal tasking context (but
 *     interrupts siabled).  The implementation must take whatever actions
 *     are necessary to assure that the operation is safe within this context.
 *   - Upon return, the caller will sleep waiting for the page fill callback
 *     to occur.  The callback function will perform the wakeup.
 *
 ****************************************************************************/

#ifdef CONFIG_PAGING_BLOCKINGFILL
int up_fillpage(FAR _TCB *tcb, FAR void *vpage)
{
  pglldbg("TCB: %p vpage: %d far: %08x\n", tcb, vpage, tcb->xcp.far);
# warning "Not implemented"
  return -ENOSYS;
}
#else
int up_fillpage(FAR _TCB *tcb, FAR void *vpage, up_pgcallback_t pg_callback)
{
  pglldbg("TCB: %p vpage: %d far: %08x\n", tcb, vpage, tcb->xcp.far);
# warning "Not implemented"
  return -ENOSYS;
}
#endif

#endif /* CONFIG_PAGING */