arch/x86_64/pmap.c

5  * x86_64 specific management of page tables
10  * sized page is the number of page table levels + 1.
13  * Warning: Additional slots will be required to map a BASE_PAGE_SIZE size page,
67 // returns whether va1 and va2 share a page directory entry
74 // returns whether va1 and va2 share a page directory pointer table entry
79 // returns whether va1 and va2 share a page map level 4 entry
136  * \brief Returns the vnode for the page directory mapping a given vspace
213  * \brief Returns the vnode for the page directory pointer table mapping for a
226  * \brief Returns the vnode for the page directory mapping a given vspace
306             printf("page already exists in 0x%"
310             // clean out empty page tables. We do this here because we benefit
311             // from having the page tables in place when doing lots of small
318     struct vnode *page = slab_alloc(&pmap->p.m.slab);
319     assert(page);
320     page->v.is_vnode = false;
321     page->is_cloned = false;
322     page->v.entry = table_base;
323     page->v.cap = frame;
324     page->v.u.frame.offset = offset;
325     page->v.u.frame.flags = flags;
326     page->v.u.frame.pte_count = pte_count;
327     page->u.frame.vaddr = vaddr;
328     page->u.frame.cloned_count = 0;
331     pmap_vnode_insert_child(ptable, page);
333     set_mapping_cap(&pmap->p, page, ptable, table_base);
338     assert(!capref_is_null(page->v.mapping));
340                     pmap_flags, offset, pte_count, page->v.mapping);
359     // determine page size and relevant address part
378         // huge page branch (1GB)
390         // large page branch (2MB)
400     // round to the next full page and calculate end address and #ptes
418                 "; pte_count = %zd; frame bytes = 0x%zx; page size = 0x%zx\n",
437     else { // multiple leaf page tables
538  * \brief Create page mappings
565     // Adjust the parameters to page boundaries
608     struct vnode *page;
618  * \arg pt the last-level page table meta-data we found if any
619  * \arg page the page meta-data we found if any
625     struct vnode *pdpt = NULL, *pdir = NULL, *pt = NULL, *page = NULL;
631     // find page and last-level page table (can be pdir or pdpt)
633         page = pmap_find_vnode(pdpt, X86_64_PDPT_BASE(vaddr));
634         if (page && page->v.is_vnode) { // not 1G pages
635             pdir = page;
636             page = pmap_find_vnode(pdir, X86_64_PDIR_BASE(vaddr));
637             if (page && page->v.is_vnode) { // not 2M pages
638                 pt = page;
639                 page = pmap_find_vnode(pt, X86_64_PTABLE_BASE(vaddr));
643             } else if (page) {
644                 assert(is_large_page(page));
650         } else if (page) {
651             assert(is_huge_page(page));
660         info->page = page;
665     if (pt && page) {
681     assert(info.page_table && info.page_table->v.is_vnode && info.page && !info.page->v.is_vnode);
683     if (info.page->v.u.frame.pte_count == pte_count) {
684         err = vnode_unmap(info.page_table->v.cap, info.page->v.mapping);
691         // delete&free page->v.mapping after doing vnode_unmap()
692         err = cap_delete(info.page->v.mapping);
697         err = pmap->p.slot_alloc->free(pmap->p.slot_alloc, info.page->v.mapping);
706         pmap_remove_vnode(info.page_table, info.page);
707         slab_free(&pmap->p.m.slab, info.page);
714  * \brief Remove page mappings
729     //determine if we unmap a larger page
738     assert(!info.page->v.is_vnode);
740     if (info.page->v.entry > info.table_base) {
752         (is_same_pdpt(vaddr, vend) && is_large_page(info.page)) ||
753         (is_same_pml4(vaddr, vend) && is_huge_page(info.page)))
824     assert(info.page_table && info.page_table->v.is_vnode && info.page && !info.page->v.is_vnode);
830         // page (as offset from first page in mapping), #affected
833         size_t off = info.table_base - info.page->v.entry;
848              * default strategy is to only use selective flushing for single page
851                 // do assisted selective flush for single page
855         err = invoke_mapping_modify_flags(info.page->v.mapping, off, pages,
869  * \brief Modify page mapping
884     //determine if we unmap a larger page
892     assert(info.page && !info.page->v.is_vnode);
905         (is_same_pdpt(vaddr, vend) && is_large_page(info.page)) ||
906         (is_same_pml4(vaddr, vend) && is_huge_page(info.page))) {
960  * \brief Query existing page mapping
987         info->vaddr = find_info.page->u.frame.vaddr;
988         info->size = find_info.page_size * find_info.page->v.u.frame.pte_count;
989         info->cap = find_info.page->v.cap;
990         info->offset = find_info.page->v.u.frame.offset;
991         info->flags = find_info.page->v.u.frame.flags;
992         info->mapping = find_info.page->v.mapping;
1101  * creates pinned page table entries
1140     /* do the actual creation of the page tables */
1154         /* map the page-table read only for access to status bits */
1161         /* copy the page-table capability */
1183         /* get the page table of the reserved range and map the PT */
1212     // find page and last-level page table (can be pdir or pdpt)
1357          * provide the mapping cnode for the first half of the root page table as