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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. /** @addtogroup genarchmm
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Address space functions for 4-level hierarchical pagetables.
  36.  */
  37.  
  38. #include <genarch/mm/page_pt.h>
  39. #include <mm/page.h>
  40. #include <mm/frame.h>
  41. #include <mm/as.h>
  42. #include <synch/mutex.h>
  43. #include <arch/mm/page.h>
  44. #include <arch/mm/as.h>
  45. #include <arch/types.h>
  46. #include <typedefs.h>
  47. #include <memstr.h>
  48. #include <arch.h>
  49.  
  50. static pte_t *ptl0_create(int flags);
  51. static void ptl0_destroy(pte_t *page_table);
  52.  
  53. static void pt_lock(as_t *as, bool lock);
  54. static void pt_unlock(as_t *as, bool unlock);
  55.  
  56. as_operations_t as_pt_operations = {
  57.     .page_table_create = ptl0_create,
  58.     .page_table_destroy = ptl0_destroy,
  59.     .page_table_lock = pt_lock,
  60.     .page_table_unlock = pt_unlock
  61. };
  62.  
  63. /** Create PTL0.
  64.  *
  65.  * PTL0 of 4-level page table will be created for each address space.
  66.  *
  67.  * @param flags Flags can specify whether ptl0 is for the kernel address space.
  68.  *
  69.  * @return New PTL0.
  70.  */
  71. pte_t *ptl0_create(int flags)
  72. {
  73.     pte_t *src_ptl0, *dst_ptl0;
  74.     ipl_t ipl;
  75.  
  76.     dst_ptl0 = (pte_t *) frame_alloc(ONE_FRAME, FRAME_KA);
  77.  
  78.     if (flags & FLAG_AS_KERNEL) {
  79.         memsetb((uintptr_t) dst_ptl0, PAGE_SIZE, 0);
  80.     } else {
  81.         uintptr_t src, dst;
  82.    
  83.         /*
  84.          * Copy the kernel address space portion to new PTL0.
  85.          */
  86.          
  87.         ipl = interrupts_disable();
  88.         mutex_lock(&AS_KERNEL->lock);      
  89.         src_ptl0 = (pte_t *) PA2KA((uintptr_t) AS_KERNEL->page_table);
  90.  
  91.         src = (uintptr_t) &src_ptl0[PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)];
  92.         dst = (uintptr_t) &dst_ptl0[PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)];
  93.  
  94.         memsetb((uintptr_t) dst_ptl0, PAGE_SIZE, 0);
  95.         memcpy((void *) dst, (void *) src, PAGE_SIZE - (src - (uintptr_t) src_ptl0));
  96.         mutex_unlock(&AS_KERNEL->lock);
  97.         interrupts_restore(ipl);
  98.     }
  99.  
  100.     return (pte_t *) KA2PA((uintptr_t) dst_ptl0);
  101. }
  102.  
  103. /** Destroy page table.
  104.  *
  105.  * Destroy PTL0, other levels are expected to be already deallocated.
  106.  *
  107.  * @param page_table Physical address of PTL0.
  108.  */
  109. void ptl0_destroy(pte_t *page_table)
  110. {
  111.     frame_free((uintptr_t)page_table);
  112. }
  113.  
  114. /** Lock page tables.
  115.  *
  116.  * Lock only the address space.
  117.  * Interrupts must be disabled.
  118.  *
  119.  * @param as Address space.
  120.  * @param lock If false, do not attempt to lock the address space.
  121.  */
  122. void pt_lock(as_t *as, bool lock)
  123. {
  124.     if (lock)
  125.         mutex_lock(&as->lock);
  126. }
  127.  
  128. /** Unlock page tables.
  129.  *
  130.  * Unlock the address space.
  131.  * Interrupts must be disabled.
  132.  *
  133.  * @param as Address space.
  134.  * @param unlock If false, do not attempt to unlock the address space.
  135.  */
  136. void pt_unlock(as_t *as, bool unlock)
  137. {
  138.     if (unlock)
  139.         mutex_unlock(&as->lock);
  140. }
  141.  
  142. /** @}
  143.  */
  144.