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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 (VAT) for global page hash table. |
| */ |
| |
| #include <genarch/mm/page_ht.h> |
| #include <mm/page.h> |
| #include <arch/mm/page.h> |
| #include <mm/frame.h> |
| #include <mm/slab.h> |
| #include <mm/as.h> |
| #include <arch/mm/asid.h> |
| #include <arch/types.h> |
| #include <arch/asm.h> |
| #include <synch/spinlock.h> |
| #include <arch.h> |
| #include <debug.h> |
| #include <memstr.h> |
| #include <adt/hash_table.h> |
| #include <align.h> |
| |
| static index_t hash(unative_t key[]); |
| static bool compare(unative_t key[], count_t keys, link_t *item); |
| static void remove_callback(link_t *item); |
| |
| static void ht_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, |
| int flags); |
| static void ht_mapping_remove(as_t *as, uintptr_t page); |
| static pte_t *ht_mapping_find(as_t *as, uintptr_t page); |
| |
| /** |
| * This lock protects the page hash table. It must be acquired |
| * after address space lock and after any address space area |
| * locks. |
| */ |
| mutex_t page_ht_lock; |
| |
| /** |
| * Page hash table. |
| * The page hash table may be accessed only when page_ht_lock is held. |
| */ |
| hash_table_t page_ht; |
| |
| /** Hash table operations for page hash table. */ |
| hash_table_operations_t ht_operations = { |
| .hash = hash, |
| .compare = compare, |
| .remove_callback = remove_callback |
| }; |
| |
| /** Page mapping operations for page hash table architectures. */ |
| page_mapping_operations_t ht_mapping_operations = { |
| .mapping_insert = ht_mapping_insert, |
| .mapping_remove = ht_mapping_remove, |
| .mapping_find = ht_mapping_find |
| }; |
| |
| /** Compute page hash table index. |
| * |
| * @param key Array of two keys (i.e. page and address space). |
| * |
| * @return Index into page hash table. |
| */ |
| index_t hash(unative_t key[]) |
| { |
| as_t *as = (as_t *) key[KEY_AS]; |
| uintptr_t page = (uintptr_t) key[KEY_PAGE]; |
| index_t index; |
| |
| /* |
| * Virtual page addresses have roughly the same probability |
| * of occurring. Least significant bits of VPN compose the |
| * hash index. |
| */ |
| index = ((page >> PAGE_WIDTH) & (PAGE_HT_ENTRIES - 1)); |
| |
| /* |
| * Address space structures are likely to be allocated from |
| * similar addresses. Least significant bits compose the |
| * hash index. |
| */ |
| index |= ((unative_t) as) & (PAGE_HT_ENTRIES - 1); |
| |
| return index; |
| } |
| |
| /** Compare page hash table item with page and/or address space. |
| * |
| * @param key Array of one or two keys (i.e. page and/or address space). |
| * @param keys Number of keys passed. |
| * @param item Item to compare the keys with. |
| * |
| * @return true on match, false otherwise. |
| */ |
| bool compare(unative_t key[], count_t keys, link_t *item) |
| { |
| pte_t *t; |
| |
| ASSERT(item); |
| ASSERT((keys > 0) && (keys <= PAGE_HT_KEYS)); |
| |
| /* |
| * Convert item to PTE. |
| */ |
| t = hash_table_get_instance(item, pte_t, link); |
| |
| if (keys == PAGE_HT_KEYS) { |
| return (key[KEY_AS] == (uintptr_t) t->as) && |
| (key[KEY_PAGE] == t->page); |
| } else { |
| return (key[KEY_AS] == (uintptr_t) t->as); |
| } |
| } |
| |
| /** Callback on page hash table item removal. |
| * |
| * @param item Page hash table item being removed. |
| */ |
| void remove_callback(link_t *item) |
| { |
| pte_t *t; |
| |
| ASSERT(item); |
| |
| /* |
| * Convert item to PTE. |
| */ |
| t = hash_table_get_instance(item, pte_t, link); |
| |
| free(t); |
| } |
| |
| /** Map page to frame using page hash table. |
| * |
| * 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 which 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 ht_mapping_insert(as_t *as, uintptr_t page, uintptr_t frame, int flags) |
| { |
| pte_t *t; |
| unative_t key[2] = { |
| (uintptr_t) as, |
| page = ALIGN_DOWN(page, PAGE_SIZE) |
| }; |
| |
| if (!hash_table_find(&page_ht, key)) { |
| t = (pte_t *) malloc(sizeof(pte_t), FRAME_ATOMIC); |
| ASSERT(t != NULL); |
| |
| t->g = (flags & PAGE_GLOBAL) != 0; |
| t->x = (flags & PAGE_EXEC) != 0; |
| t->w = (flags & PAGE_WRITE) != 0; |
| t->k = !(flags & PAGE_USER); |
| t->c = (flags & PAGE_CACHEABLE) != 0; |
| t->p = !(flags & PAGE_NOT_PRESENT); |
| |
| t->as = as; |
| t->page = ALIGN_DOWN(page, PAGE_SIZE); |
| t->frame = ALIGN_DOWN(frame, FRAME_SIZE); |
| |
| hash_table_insert(&page_ht, key, &t->link); |
| } |
| } |
| |
| /** Remove mapping of page from page hash table. |
| * |
| * Remove any mapping of page within address space as. |
| * TLB shootdown should follow in order to make effects of |
| * this call visible. |
| * |
| * 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 ht_mapping_remove(as_t *as, uintptr_t page) |
| { |
| unative_t key[2] = { |
| (uintptr_t) as, |
| page = ALIGN_DOWN(page, PAGE_SIZE) |
| }; |
| |
| /* |
| * Note that removed PTE's will be freed |
| * by remove_callback(). |
| */ |
| hash_table_remove(&page_ht, key, 2); |
| } |
| |
| |
| /** Find mapping for virtual page in page hash table. |
| * |
| * Find mapping for virtual page. |
| * |
| * The page table must be locked and interrupts must be disabled. |
| * |
| * @param as Address space to wich page belongs. |
| * @param page Virtual page. |
| * |
| * @return NULL if there is no such mapping; requested mapping otherwise. |
| */ |
| pte_t *ht_mapping_find(as_t *as, uintptr_t page) |
| { |
| link_t *hlp; |
| pte_t *t = NULL; |
| unative_t key[2] = { |
| (uintptr_t) as, |
| page = ALIGN_DOWN(page, PAGE_SIZE) |
| }; |
| |
| hlp = hash_table_find(&page_ht, key); |
| if (hlp) |
| t = hash_table_get_instance(hlp, pte_t, link); |
| |
| return t; |
| } |
| |
| /** @} |
| */ |