/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_PGTABLE_32_H #define _ASM_X86_PGTABLE_32_H #include /* * The Linux memory management assumes a three-level page table setup. On * the i386, we use that, but "fold" the mid level into the top-level page * table, so that we physically have the same two-level page table as the * i386 mmu expects. * * This file contains the functions and defines necessary to modify and use * the i386 page table tree. */ #ifndef __ASSEMBLY__ #include #include #include #include #include #include struct mm_struct; struct vm_area_struct; extern pgd_t swapper_pg_dir[1024]; extern pgd_t initial_page_table[1024]; extern pmd_t initial_pg_pmd[]; static inline void pgtable_cache_init(void) { } static inline void check_pgt_cache(void) { } void paging_init(void); void sync_initial_page_table(void); /* * Define this if things work differently on an i386 and an i486: * it will (on an i486) warn about kernel memory accesses that are * done without a 'access_ok(VERIFY_WRITE,..)' */ #undef TEST_ACCESS_OK #ifdef CONFIG_X86_PAE # include #else # include #endif #if defined(CONFIG_HIGHPTE) #define pte_offset_map(dir, address) \ ((pte_t *)kmap_atomic(pmd_page(*(dir))) + \ pte_index((address))) #define pte_unmap(pte) kunmap_atomic((pte)) #else #define pte_offset_map(dir, address) \ ((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address))) #define pte_unmap(pte) do { } while (0) #endif /* Clear a kernel PTE and flush it from the TLB */ #define kpte_clear_flush(ptep, vaddr) \ do { \ pte_clear(&init_mm, (vaddr), (ptep)); \ __flush_tlb_one_kernel((vaddr)); \ } while (0) #endif /* !__ASSEMBLY__ */ /* * kern_addr_valid() is (1) for FLATMEM and (0) for * SPARSEMEM and DISCONTIGMEM */ #ifdef CONFIG_FLATMEM #define kern_addr_valid(addr) (1) #else #define kern_addr_valid(kaddr) (0) #endif /* * This is how much memory in addition to the memory covered up to * and including _end we need mapped initially. * We need: * (KERNEL_IMAGE_SIZE/4096) / 1024 pages (worst case, non PAE) * (KERNEL_IMAGE_SIZE/4096) / 512 + 4 pages (worst case for PAE) * * Modulo rounding, each megabyte assigned here requires a kilobyte of * memory, which is currently unreclaimed. * * This should be a multiple of a page. * * KERNEL_IMAGE_SIZE should be greater than pa(_end) * and small than max_low_pfn, otherwise will waste some page table entries */ #if PTRS_PER_PMD > 1 #define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD) #else #define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD) #endif /* * Number of possible pages in the lowmem region. * * We shift 2 by 31 instead of 1 by 32 to the left in order to avoid a * gas warning about overflowing shift count when gas has been compiled * with only a host target support using a 32-bit type for internal * representation. */ #define LOWMEM_PAGES ((((_ULL(2)<<31) - __PAGE_OFFSET) >> PAGE_SHIFT)) #endif /* _ASM_X86_PGTABLE_32_H */