kernel/arch/arm32/src/ras.c

   1 /*
   2  * Copyright (c) 2009 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup kernel_arm32
  30  * @{
  31  */
  32 /** @file
  33  *  @brief Kernel part of Restartable Atomic Sequences support.
  34  */
  35
  36 #include <arch/ras.h>
  37 #include <mm/mm.h>
  38 #include <mm/frame.h>
  39 #include <mm/page.h>
  40 #include <mm/km.h>
  41 #include <mm/tlb.h>
  42 #include <mm/asid.h>
  43 #include <interrupt.h>
  44 #include <arch/exception.h>
  45 #include <arch.h>
  46 #include <memw.h>
  47 #include <typedefs.h>
  48
  49 uintptr_t *ras_page = NULL;
  50
  51 void ras_init(void)
  52 {
  53         uintptr_t frame = frame_alloc(1, FRAME_HIGHMEM, 0);
  54
  55         ras_page = (uintptr_t *) km_map(frame, PAGE_SIZE, PAGE_SIZE,
  56             PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_CACHEABLE);
  57
  58         memsetb(ras_page, PAGE_SIZE, 0);
  59         ras_page[RAS_START] = 0;
  60         ras_page[RAS_END] = 0xffffffff;
  61 }
  62
  63 void ras_check(unsigned int n, istate_t *istate)
  64 {
  65         bool restart_needed = false;
  66         uintptr_t restart_pc = 0;
  67
  68         if (istate_from_uspace(istate)) {
  69                 if (ras_page[RAS_START]) {
  70                         if ((ras_page[RAS_START] < istate->pc) &&
  71                             (ras_page[RAS_END] > istate->pc)) {
  72                                 restart_needed = true;
  73                                 restart_pc = ras_page[RAS_START];
  74                         }
  75                         ras_page[RAS_START] = 0;
  76                         ras_page[RAS_END] = 0xffffffff;
  77                 }
  78         }
  79
  80         exc_dispatch(n, istate);
  81         if (restart_needed)
  82                 istate->pc = restart_pc;
  83 }
  84
  85 /** @}
  86  */