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Line 101... Line 101...
101 
 *
 101 
 *
102 
 * Remove any mapping of 'page' within address space 'as'.
 102 
 * Remove any mapping of 'page' within address space 'as'.
103 
 * TLB shootdown should follow in order to make effects of
 103 
 * TLB shootdown should follow in order to make effects of
104 
 * this call visible.
 104 
 * this call visible.
105 
 *
 105 
 *
- 
 
 106 
 * Empty page tables except PTL0 are freed.
- 
 
 107 
 *
106 
 * The address space must be locked and interrupts must be disabled.
 108 
 * The address space must be locked and interrupts must be disabled.
107 
 *
 109 
 *
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 * @param as Address space to wich page belongs.
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 * @param as Address space to wich page belongs.
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 * @param page Virtual address of the page to be demapped.
 111 
 * @param page Virtual address of the page to be demapped.
110 
 */
 112 
 */
111 
void pt_mapping_remove(as_t *as, __address page)
 113 
void pt_mapping_remove(as_t *as, __address page)
112 
{
 114 
{
113 
    pte_t *ptl0, *ptl1, *ptl2, *ptl3;
 115 
    pte_t *ptl0, *ptl1, *ptl2, *ptl3;
- 
 
 116 
    bool empty = true;
- 
 
 117 
    int i;
- 
 
 118 
 
- 
 
 119 
    /*
- 
 
 120 
     * First, remove the mapping, if it exists.
- 
 
 121 
     */
114 
 
 122 
 
115 
    ptl0 = (pte_t *) PA2KA((__address) as->page_table);
 123 
    ptl0 = (pte_t *) PA2KA((__address) as->page_table);
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 124 
 
117 
    if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT)
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    if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT)
118 
        return;
 126 
        return;
Line 129... Line 137...
129 
 
 137 
 
130 
    ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
 138 
    ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
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 139 
 
132 
    /* Destroy the mapping. Setting to PAGE_NOT_PRESENT is not sufficient. */
 140 
    /* Destroy the mapping. Setting to PAGE_NOT_PRESENT is not sufficient. */
133 
    memsetb((__address) &ptl3[PTL3_INDEX(page)], sizeof(pte_t), 0);
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    memsetb((__address) &ptl3[PTL3_INDEX(page)], sizeof(pte_t), 0);
- 
 
 142 
 
- 
 
 143 
    /*
- 
 
 144 
     * Second, free all empty tables along the way from PTL3 down to PTL0.
- 
 
 145 
     */
- 
 
 146 
   
- 
 
 147 
    /* check PTL3 */
- 
 
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    for (i = 0; i < PTL3_ENTRIES; i++) {
- 
 
 149 
        if (PTE_VALID(&ptl3[i])) {
- 
 
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            empty = false;
- 
 
 151 
            break;
- 
 
 152 
        }
- 
 
 153 
    }
- 
 
 154 
    if (empty) {
- 
 
 155 
        /*
- 
 
 156 
         * PTL3 is empty.
- 
 
 157 
         * Release the frame and remove PTL3 pointer from preceding table.
- 
 
 158 
         */
- 
 
 159 
        frame_free(ADDR2PFN(KA2PA((__address) ptl3)));
- 
 
 160 
        if (PTL2_ENTRIES)
- 
 
 161 
            memsetb((__address) &ptl2[PTL2_INDEX(page)], sizeof(pte_t), 0);
- 
 
 162 
        else if (PTL1_ENTRIES)
- 
 
 163 
            memsetb((__address) &ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0);
- 
 
 164 
        else
- 
 
 165 
            memsetb((__address) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
- 
 
 166 
    } else {
- 
 
 167 
        /*
- 
 
 168 
         * PTL3 is not empty.
- 
 
 169 
         * Therefore, there must be a path from PTL0 to PTL3 and
- 
 
 170 
         * thus nothing to free in higher levels.
- 
 
 171 
         */
- 
 
 172 
        return;
- 
 
 173 
    }
- 
 
 174 
   
- 
 
 175 
    /* check PTL2, empty is still true */
- 
 
 176 
    if (PTL2_ENTRIES) {
- 
 
 177 
        for (i = 0; i < PTL2_ENTRIES; i++) {
- 
 
 178 
            if (PTE_VALID(&ptl2[i])) {
- 
 
 179 
                empty = false;
- 
 
 180 
                break;
- 
 
 181 
            }
- 
 
 182 
        }
- 
 
 183 
        if (empty) {
- 
 
 184 
            /*
- 
 
 185 
             * PTL2 is empty.
- 
 
 186 
             * Release the frame and remove PTL2 pointer from preceding table.
- 
 
 187 
             */
- 
 
 188 
            frame_free(ADDR2PFN(KA2PA((__address) ptl2)));
- 
 
 189 
            if (PTL1_ENTRIES)
- 
 
 190 
                memsetb((__address) &ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0);
- 
 
 191 
            else
- 
 
 192 
                memsetb((__address) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
- 
 
 193 
        }
- 
 
 194 
        else {
- 
 
 195 
            /*
- 
 
 196 
             * PTL2 is not empty.
- 
 
 197 
             * Therefore, there must be a path from PTL0 to PTL2 and
- 
 
 198 
             * thus nothing to free in higher levels.
- 
 
 199 
             */
- 
 
 200 
            return;
- 
 
 201 
        }
- 
 
 202 
    }
- 
 
 203 
 
- 
 
 204 
    /* check PTL1, empty is still true */
- 
 
 205 
    if (PTL1_ENTRIES) {
- 
 
 206 
        for (i = 0; i < PTL1_ENTRIES; i++) {
- 
 
 207 
            if (PTE_VALID(&ptl1[i])) {
- 
 
 208 
                empty = false;
- 
 
 209 
                break;
- 
 
 210 
            }
- 
 
 211 
        }
- 
 
 212 
        if (empty) {
- 
 
 213 
            /*
- 
 
 214 
             * PTL1 is empty.
- 
 
 215 
             * Release the frame and remove PTL1 pointer from preceding table.
- 
 
 216 
             */
- 
 
 217 
            frame_free(ADDR2PFN(KA2PA((__address) ptl1)));
- 
 
 218 
            memsetb((__address) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0);
- 
 
 219 
        }
- 
 
 220 
    }
- 
 
 221 
 
134 
}
 222 
}
135 
 
 223 
 
136 
/** Find mapping for virtual page in hierarchical page tables.
 224 
/** Find mapping for virtual page in hierarchical page tables.
137 
 *
 225 
 *
138 
 * Find mapping for virtual page.
 226 
 * Find mapping for virtual page.