/****************************************************************************
* arch/arm/src/armv7-a/arm_prefetchabort.c
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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>
/* Output debug info if stack dump is selected -- even if debug is not
* selected.
*/
#ifdef CONFIG_ARCH_STACKDUMP
# undef CONFIG_DEBUG
# undef CONFIG_DEBUG_VERBOSE
# define CONFIG_DEBUG 1
# define CONFIG_DEBUG_VERBOSE 1
#endif
#include <stdint.h>
#include <debug.h>
#include <nuttx/irq.h>
#ifdef CONFIG_PAGING
# include <nuttx/page.h>
#endif
#include "sched/sched.h"
#include "up_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: arm_prefetchabort
*
* Description;
* This is the prefetch abort exception handler. The ARM prefetch abort
* exception occurs when a memory fault is detected during an an
* instruction fetch.
*
****************************************************************************/
#ifdef CONFIG_PAGING
uint32_t *arm_prefetchabort(uint32_t *regs, uint32_t ifar, uint32_t ifsr)
{
uint32_t *savestate;
/* Save the saved processor context in current_regs where it can be accessed
* for register dumps and possibly context switching.
*/
savestate = (uint32_t*)current_regs;
current_regs = regs;
/* Get the (virtual) address of instruction that caused the prefetch abort.
* When the exception occurred, this address was provided in the lr register
* and this value was saved in the context save area as the PC at the
* REG_R15 index.
*
* Check to see if this miss address is within the configured range of
* virtual addresses.
*/
pglldbg("VADDR: %08x VBASE: %08x VEND: %08x\n",
regs[REG_PC], PG_PAGED_VBASE, PG_PAGED_VEND);
if (regs[REG_R15] >= PG_PAGED_VBASE && regs[REG_R15] < PG_PAGED_VEND)
{
/* Save the offending PC as the fault address in the TCB of the currently
* executing task. This value is, of course, already known in regs[REG_R15],
* but saving it in this location will allow common paging logic for both
* prefetch and data aborts.
*/
FAR struct tcb_s *tcb = (FAR struct tcb_s *)g_readytorun.head;
tcb->xcp.far = regs[REG_R15];
/* Call pg_miss() to schedule the page fill. A consequences of this
* call are:
*
* (1) The currently executing task will be blocked and saved on
* on the g_waitingforfill task list.
* (2) An interrupt-level context switch will occur so that when
* this function returns, it will return to a different task,
* most likely the page fill worker thread.
* (3) The page fill worker task has been signalled and should
* execute immediately when we return from this exception.
*/
pg_miss();
/* Restore the previous value of current_regs. NULL would indicate that
* we are no longer in an interrupt handler. It will be non-NULL if we
* are returning from a nested interrupt.
*/
current_regs = savestate;
}
else
{
lldbg("Prefetch abort. PC: %08x IFAR: %08x IFSR: %08x\n",
regs[REG_PC], ifar, ifsr);
PANIC();
}
return regs;
}
#else /* CONFIG_PAGING */
uint32_t *arm_prefetchabort(uint32_t *regs, uint32_t ifar, uint32_t ifsr)
{
/* Save the saved processor context in current_regs where it can be accessed
* for register dumps and possibly context switching.
*/
current_regs = regs;
/* Crash -- possibly showing diagnostic debug information. */
lldbg("Prefetch abort. PC: %08x IFAR: %08x IFSR: %08x\n",
regs[REG_PC], ifar, ifsr);
PANIC();
return regs; /* To keep the compiler happy */
}
#endif /* CONFIG_PAGING */
