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