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  1. /*
  2.  * Copyright (C) 2006 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. /**
  30.  * @file    as_pt.c
  31.  * @brief   Address space functions for 4-level hierarchical pagetables.
  32.  */
  33.  
  34. #include <genarch/mm/page_pt.h>
  35. #include <mm/page.h>
  36. #include <mm/frame.h>
  37. #include <mm/as.h>
  38. #include <synch/mutex.h>
  39. #include <arch/mm/page.h>
  40. #include <arch/mm/as.h>
  41. #include <arch/types.h>
  42. #include <typedefs.h>
  43. #include <memstr.h>
  44. #include <arch.h>
  45.  
  46. static pte_t *ptl0_create(int flags);
  47. static void ptl0_destroy(pte_t *page_table);
  48.  
  49. static void pt_lock(as_t *as, bool lock);
  50. static void pt_unlock(as_t *as, bool unlock);
  51.  
  52. as_operations_t as_pt_operations = {
  53.     .page_table_create = ptl0_create,
  54.     .page_table_destroy = ptl0_destroy,
  55.     .page_table_lock = pt_lock,
  56.     .page_table_unlock = pt_unlock
  57. };
  58.  
  59. /** Create PTL0.
  60.  *
  61.  * PTL0 of 4-level page table will be created for each address space.
  62.  *
  63.  * @param flags Flags can specify whether ptl0 is for the kernel address space.
  64.  *
  65.  * @return New PTL0.
  66.  */
  67. pte_t *ptl0_create(int flags)
  68. {
  69.     pte_t *src_ptl0, *dst_ptl0;
  70.     ipl_t ipl;
  71.  
  72.     dst_ptl0 = (pte_t *) PA2KA(PFN2ADDR(frame_alloc(ONE_FRAME, FRAME_KA | FRAME_PANIC)));
  73.  
  74.     if (flags & FLAG_AS_KERNEL) {
  75.         memsetb((__address) dst_ptl0, PAGE_SIZE, 0);
  76.     } else {
  77.         __address src, dst;
  78.    
  79.         /*
  80.          * Copy the kernel address space portion to new PTL0.
  81.          */
  82.          
  83.         ipl = interrupts_disable();
  84.         mutex_lock(&AS_KERNEL->lock);      
  85.         src_ptl0 = (pte_t *) PA2KA((__address) AS_KERNEL->page_table);
  86.  
  87.         src = (__address) &src_ptl0[PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)];
  88.         dst = (__address) &dst_ptl0[PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)];
  89.  
  90.         memsetb((__address) dst_ptl0, PAGE_SIZE, 0);
  91.         memcpy((void *) dst, (void *) src, PAGE_SIZE - (src - (__address) src_ptl0));
  92.         mutex_unlock(&AS_KERNEL->lock);
  93.         interrupts_restore(ipl);
  94.     }
  95.  
  96.     return (pte_t *) KA2PA((__address) dst_ptl0);
  97. }
  98.  
  99. /** Destroy page table.
  100.  *
  101.  * Destroy PTL0, other levels are expected to be already deallocated.
  102.  *
  103.  * @param page_table Physical address of PTL0.
  104.  */
  105. void ptl0_destroy(pte_t *page_table)
  106. {
  107.     frame_free(ADDR2PFN((__address) page_table));
  108. }
  109.  
  110. /** Lock page tables.
  111.  *
  112.  * Lock only the address space.
  113.  * Interrupts must be disabled.
  114.  *
  115.  * @param as Address space.
  116.  * @param lock If false, do not attempt to lock the address space.
  117.  */
  118. void pt_lock(as_t *as, bool lock)
  119. {
  120.     if (lock)
  121.         mutex_lock(&as->lock);
  122. }
  123.  
  124. /** Unlock page tables.
  125.  *
  126.  * Unlock the address space.
  127.  * Interrupts must be disabled.
  128.  *
  129.  * @param as Address space.
  130.  * @param unlock If false, do not attempt to unlock the address space.
  131.  */
  132. void pt_unlock(as_t *as, bool unlock)
  133. {
  134.     if (unlock)
  135.         mutex_unlock(&as->lock);
  136. }
  137.