2 * Copyright (c) 2006 Jakub Jermar
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
29 /** @addtogroup genarchmm
35 * @brief Virtual Address Translation for hierarchical 4-level page tables.
38 #include <genarch/mm/page_pt.h>
42 #include <arch/mm/page.h>
43 #include <arch/mm/as.h>
44 #include <arch/types.h>
48 static void pt_mapping_insert(as_t
*as
, uintptr_t page
, uintptr_t frame
, int flags
);
49 static void pt_mapping_remove(as_t
*as
, uintptr_t page
);
50 static pte_t
*pt_mapping_find(as_t
*as
, uintptr_t page
);
52 page_mapping_operations_t pt_mapping_operations
= {
53 .mapping_insert
= pt_mapping_insert
,
54 .mapping_remove
= pt_mapping_remove
,
55 .mapping_find
= pt_mapping_find
58 /** Map page to frame using hierarchical page tables.
60 * Map virtual address page to physical address frame
63 * The page table must be locked and interrupts must be disabled.
65 * @param as Address space to wich page belongs.
66 * @param page Virtual address of the page to be mapped.
67 * @param frame Physical address of memory frame to which the mapping is done.
68 * @param flags Flags to be used for mapping.
70 void pt_mapping_insert(as_t
*as
, uintptr_t page
, uintptr_t frame
, int flags
)
72 pte_t
*ptl0
, *ptl1
, *ptl2
, *ptl3
;
75 ptl0
= (pte_t
*) PA2KA((uintptr_t) as
->genarch
.page_table
);
77 if (GET_PTL1_FLAGS(ptl0
, PTL0_INDEX(page
)) & PAGE_NOT_PRESENT
) {
78 newpt
= (pte_t
*)frame_alloc(ONE_FRAME
, FRAME_KA
);
79 memsetb((uintptr_t)newpt
, PAGE_SIZE
, 0);
80 SET_PTL1_ADDRESS(ptl0
, PTL0_INDEX(page
), KA2PA(newpt
));
81 SET_PTL1_FLAGS(ptl0
, PTL0_INDEX(page
), PAGE_PRESENT
| PAGE_USER
| PAGE_EXEC
| PAGE_CACHEABLE
| PAGE_WRITE
);
84 ptl1
= (pte_t
*) PA2KA(GET_PTL1_ADDRESS(ptl0
, PTL0_INDEX(page
)));
86 if (GET_PTL2_FLAGS(ptl1
, PTL1_INDEX(page
)) & PAGE_NOT_PRESENT
) {
87 newpt
= (pte_t
*)frame_alloc(ONE_FRAME
, FRAME_KA
);
88 memsetb((uintptr_t)newpt
, PAGE_SIZE
, 0);
89 SET_PTL2_ADDRESS(ptl1
, PTL1_INDEX(page
), KA2PA(newpt
));
90 SET_PTL2_FLAGS(ptl1
, PTL1_INDEX(page
), PAGE_PRESENT
| PAGE_USER
| PAGE_EXEC
| PAGE_CACHEABLE
| PAGE_WRITE
);
93 ptl2
= (pte_t
*) PA2KA(GET_PTL2_ADDRESS(ptl1
, PTL1_INDEX(page
)));
95 if (GET_PTL3_FLAGS(ptl2
, PTL2_INDEX(page
)) & PAGE_NOT_PRESENT
) {
96 newpt
= (pte_t
*)frame_alloc(ONE_FRAME
, FRAME_KA
);
97 memsetb((uintptr_t)newpt
, PAGE_SIZE
, 0);
98 SET_PTL3_ADDRESS(ptl2
, PTL2_INDEX(page
), KA2PA(newpt
));
99 SET_PTL3_FLAGS(ptl2
, PTL2_INDEX(page
), PAGE_PRESENT
| PAGE_USER
| PAGE_EXEC
| PAGE_CACHEABLE
| PAGE_WRITE
);
102 ptl3
= (pte_t
*) PA2KA(GET_PTL3_ADDRESS(ptl2
, PTL2_INDEX(page
)));
104 SET_FRAME_ADDRESS(ptl3
, PTL3_INDEX(page
), frame
);
105 SET_FRAME_FLAGS(ptl3
, PTL3_INDEX(page
), flags
);
108 /** Remove mapping of page from hierarchical page tables.
110 * Remove any mapping of page within address space as.
111 * TLB shootdown should follow in order to make effects of
114 * Empty page tables except PTL0 are freed.
116 * The page table must be locked and interrupts must be disabled.
118 * @param as Address space to wich page belongs.
119 * @param page Virtual address of the page to be demapped.
121 void pt_mapping_remove(as_t
*as
, uintptr_t page
)
123 pte_t
*ptl0
, *ptl1
, *ptl2
, *ptl3
;
128 * First, remove the mapping, if it exists.
131 ptl0
= (pte_t
*) PA2KA((uintptr_t) as
->genarch
.page_table
);
133 if (GET_PTL1_FLAGS(ptl0
, PTL0_INDEX(page
)) & PAGE_NOT_PRESENT
)
136 ptl1
= (pte_t
*) PA2KA(GET_PTL1_ADDRESS(ptl0
, PTL0_INDEX(page
)));
138 if (GET_PTL2_FLAGS(ptl1
, PTL1_INDEX(page
)) & PAGE_NOT_PRESENT
)
141 ptl2
= (pte_t
*) PA2KA(GET_PTL2_ADDRESS(ptl1
, PTL1_INDEX(page
)));
143 if (GET_PTL3_FLAGS(ptl2
, PTL2_INDEX(page
)) & PAGE_NOT_PRESENT
)
146 ptl3
= (pte_t
*) PA2KA(GET_PTL3_ADDRESS(ptl2
, PTL2_INDEX(page
)));
148 /* Destroy the mapping. Setting to PAGE_NOT_PRESENT is not sufficient. */
149 memsetb((uintptr_t) &ptl3
[PTL3_INDEX(page
)], sizeof(pte_t
), 0);
152 * Second, free all empty tables along the way from PTL3 down to PTL0.
156 for (i
= 0; i
< PTL3_ENTRIES
; i
++) {
157 if (PTE_VALID(&ptl3
[i
])) {
165 * Release the frame and remove PTL3 pointer from preceding table.
167 frame_free(KA2PA((uintptr_t) ptl3
));
169 memsetb((uintptr_t) &ptl2
[PTL2_INDEX(page
)], sizeof(pte_t
), 0);
170 else if (PTL1_ENTRIES
)
171 memsetb((uintptr_t) &ptl1
[PTL1_INDEX(page
)], sizeof(pte_t
), 0);
173 memsetb((uintptr_t) &ptl0
[PTL0_INDEX(page
)], sizeof(pte_t
), 0);
177 * Therefore, there must be a path from PTL0 to PTL3 and
178 * thus nothing to free in higher levels.
183 /* check PTL2, empty is still true */
185 for (i
= 0; i
< PTL2_ENTRIES
; i
++) {
186 if (PTE_VALID(&ptl2
[i
])) {
194 * Release the frame and remove PTL2 pointer from preceding table.
196 frame_free(KA2PA((uintptr_t) ptl2
));
198 memsetb((uintptr_t) &ptl1
[PTL1_INDEX(page
)], sizeof(pte_t
), 0);
200 memsetb((uintptr_t) &ptl0
[PTL0_INDEX(page
)], sizeof(pte_t
), 0);
205 * Therefore, there must be a path from PTL0 to PTL2 and
206 * thus nothing to free in higher levels.
212 /* check PTL1, empty is still true */
214 for (i
= 0; i
< PTL1_ENTRIES
; i
++) {
215 if (PTE_VALID(&ptl1
[i
])) {
223 * Release the frame and remove PTL1 pointer from preceding table.
225 frame_free(KA2PA((uintptr_t) ptl1
));
226 memsetb((uintptr_t) &ptl0
[PTL0_INDEX(page
)], sizeof(pte_t
), 0);
232 /** Find mapping for virtual page in hierarchical page tables.
234 * Find mapping for virtual page.
236 * The page table must be locked and interrupts must be disabled.
238 * @param as Address space to which page belongs.
239 * @param page Virtual page.
241 * @return NULL if there is no such mapping; entry from PTL3 describing the mapping otherwise.
243 pte_t
*pt_mapping_find(as_t
*as
, uintptr_t page
)
245 pte_t
*ptl0
, *ptl1
, *ptl2
, *ptl3
;
247 ptl0
= (pte_t
*) PA2KA((uintptr_t) as
->genarch
.page_table
);
249 if (GET_PTL1_FLAGS(ptl0
, PTL0_INDEX(page
)) & PAGE_NOT_PRESENT
)
252 ptl1
= (pte_t
*) PA2KA(GET_PTL1_ADDRESS(ptl0
, PTL0_INDEX(page
)));
254 if (GET_PTL2_FLAGS(ptl1
, PTL1_INDEX(page
)) & PAGE_NOT_PRESENT
)
257 ptl2
= (pte_t
*) PA2KA(GET_PTL2_ADDRESS(ptl1
, PTL1_INDEX(page
)));
259 if (GET_PTL3_FLAGS(ptl2
, PTL2_INDEX(page
)) & PAGE_NOT_PRESENT
)
262 ptl3
= (pte_t
*) PA2KA(GET_PTL3_ADDRESS(ptl2
, PTL2_INDEX(page
)));
264 return &ptl3
[PTL3_INDEX(page
)];