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| /* |
| * Copyright (C) 2006 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup genarchmm |
| * @{ |
| */ |
| |
| /** |
| * @file |
| * @brief Virtual Address Translation for hierarchical 4-level page tables. |
| */ |
| |
| #include <genarch/mm/page_pt.h> |
| #include <mm/page.h> |
| #include <mm/frame.h> |
| #include <mm/as.h> |
| #include <arch/mm/page.h> |
| #include <arch/mm/as.h> |
| #include <arch/types.h> |
| #include <typedefs.h> |
| #include <arch/asm.h> |
| #include <memstr.h> |
| |
| static void pt_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags); |
| static void pt_mapping_remove(as_t *as, uintptr_t page); |
| static pte_t *pt_mapping_find(as_t *as, uintptr_t page); |
| |
| page_mapping_operations_t pt_mapping_operations = { |
| .mapping_insert = pt_mapping_insert, |
| .mapping_remove = pt_mapping_remove, |
| .mapping_find = pt_mapping_find |
| }; |
| |
| /** Map page to frame using hierarchical page tables. |
| * |
| * Map virtual address page to physical address frame |
| * using flags. |
| * |
| * The page table must be locked and interrupts must be disabled. |
| * |
| * @param as Address space to wich page belongs. |
| * @param page Virtual address of the page to be mapped. |
| * @param frame Physical address of memory frame to which the mapping is done. |
| * @param flags Flags to be used for mapping. |
| */ |
| void pt_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags) |
| { |
| pte_t *ptl0, *ptl1, *ptl2, *ptl3; |
| pte_t *newpt; |
| |
| ptl0 = (pte_t *) PA2KA((uintptr_t) as->page_table); |
| |
| if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT) { |
| newpt = (pte_t *)frame_alloc(ONE_FRAME, FRAME_KA); |
| memsetb((uintptr_t)newpt, PAGE_SIZE, 0); |
| SET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page), KA2PA(newpt)); |
| SET_PTL1_FLAGS(ptl0, PTL0_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE); |
| } |
| |
| ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page))); |
| |
| if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT) { |
| newpt = (pte_t *)frame_alloc(ONE_FRAME, FRAME_KA); |
| memsetb((uintptr_t)newpt, PAGE_SIZE, 0); |
| SET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page), KA2PA(newpt)); |
| SET_PTL2_FLAGS(ptl1, PTL1_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE); |
| } |
| |
| ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page))); |
| |
| if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT) { |
| newpt = (pte_t *)frame_alloc(ONE_FRAME, FRAME_KA); |
| memsetb((uintptr_t)newpt, PAGE_SIZE, 0); |
| SET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page), KA2PA(newpt)); |
| SET_PTL3_FLAGS(ptl2, PTL2_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC | PAGE_CACHEABLE | PAGE_WRITE); |
| } |
| |
| ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page))); |
| |
| SET_FRAME_ADDRESS(ptl3, PTL3_INDEX(page), frame); |
| SET_FRAME_FLAGS(ptl3, PTL3_INDEX(page), flags); |
| } |
| |
| /** Remove mapping of page from hierarchical page tables. |
| * |
| * Remove any mapping of page within address space as. |
| * TLB shootdown should follow in order to make effects of |
| * this call visible. |
| * |
| * Empty page tables except PTL0 are freed. |
| * |
| * The page table must be locked and interrupts must be disabled. |
| * |
| * @param as Address space to wich page belongs. |
| * @param page Virtual address of the page to be demapped. |
| */ |
| void pt_mapping_remove(as_t *as, uintptr_t page) |
| { |
| pte_t *ptl0, *ptl1, *ptl2, *ptl3; |
| bool empty = true; |
| int i; |
| |
| /* |
| * First, remove the mapping, if it exists. |
| */ |
| |
| ptl0 = (pte_t *) PA2KA((uintptr_t) as->page_table); |
| |
| if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT) |
| return; |
| |
| ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page))); |
| |
| if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT) |
| return; |
| |
| ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page))); |
| |
| if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT) |
| return; |
| |
| ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page))); |
| |
| /* Destroy the mapping. Setting to PAGE_NOT_PRESENT is not sufficient. */ |
| memsetb((uintptr_t) &ptl3[PTL3_INDEX(page)], sizeof(pte_t), 0); |
| |
| /* |
| * Second, free all empty tables along the way from PTL3 down to PTL0. |
| */ |
| |
| /* check PTL3 */ |
| for (i = 0; i < PTL3_ENTRIES; i++) { |
| if (PTE_VALID(&ptl3[i])) { |
| empty = false; |
| break; |
| } |
| } |
| if (empty) { |
| /* |
| * PTL3 is empty. |
| * Release the frame and remove PTL3 pointer from preceding table. |
| */ |
| frame_free(KA2PA((uintptr_t) ptl3)); |
| if (PTL2_ENTRIES) |
| memsetb((uintptr_t) &ptl2[PTL2_INDEX(page)], sizeof(pte_t), 0); |
| else if (PTL1_ENTRIES) |
| memsetb((uintptr_t) &ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0); |
| else |
| memsetb((uintptr_t) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0); |
| } else { |
| /* |
| * PTL3 is not empty. |
| * Therefore, there must be a path from PTL0 to PTL3 and |
| * thus nothing to free in higher levels. |
| */ |
| return; |
| } |
| |
| /* check PTL2, empty is still true */ |
| if (PTL2_ENTRIES) { |
| for (i = 0; i < PTL2_ENTRIES; i++) { |
| if (PTE_VALID(&ptl2[i])) { |
| empty = false; |
| break; |
| } |
| } |
| if (empty) { |
| /* |
| * PTL2 is empty. |
| * Release the frame and remove PTL2 pointer from preceding table. |
| */ |
| frame_free(KA2PA((uintptr_t) ptl2)); |
| if (PTL1_ENTRIES) |
| memsetb((uintptr_t) &ptl1[PTL1_INDEX(page)], sizeof(pte_t), 0); |
| else |
| memsetb((uintptr_t) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0); |
| } |
| else { |
| /* |
| * PTL2 is not empty. |
| * Therefore, there must be a path from PTL0 to PTL2 and |
| * thus nothing to free in higher levels. |
| */ |
| return; |
| } |
| } |
| |
| /* check PTL1, empty is still true */ |
| if (PTL1_ENTRIES) { |
| for (i = 0; i < PTL1_ENTRIES; i++) { |
| if (PTE_VALID(&ptl1[i])) { |
| empty = false; |
| break; |
| } |
| } |
| if (empty) { |
| /* |
| * PTL1 is empty. |
| * Release the frame and remove PTL1 pointer from preceding table. |
| */ |
| frame_free(KA2PA((uintptr_t) ptl1)); |
| memsetb((uintptr_t) &ptl0[PTL0_INDEX(page)], sizeof(pte_t), 0); |
| } |
| } |
| |
| } |
| |
| /** Find mapping for virtual page in hierarchical page tables. |
| * |
| * Find mapping for virtual page. |
| * |
| * The page table must be locked and interrupts must be disabled. |
| * |
| * @param as Address space to which page belongs. |
| * @param page Virtual page. |
| * |
| * @return NULL if there is no such mapping; entry from PTL3 describing the mapping otherwise. |
| */ |
| pte_t *pt_mapping_find(as_t *as, uintptr_t page) |
| { |
| pte_t *ptl0, *ptl1, *ptl2, *ptl3; |
| |
| ptl0 = (pte_t *) PA2KA((uintptr_t) as->page_table); |
| |
| if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT) |
| return NULL; |
| |
| ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page))); |
| |
| if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT) |
| return NULL; |
| |
| ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page))); |
| |
| if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT) |
| return NULL; |
| |
| ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page))); |
| |
| return &ptl3[PTL3_INDEX(page)]; |
| } |
| |
| /** @} |
| */ |
| |