/* * include/asm-xtensa/pgtable.h * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Copyright (C) 2001 - 2013 Tensilica Inc. */ #ifndef _XTENSA_PGTABLE_H #define _XTENSA_PGTABLE_H #define __ARCH_USE_5LEVEL_HACK #include <asm/page.h> #include <asm/kmem_layout.h> #include <asm-generic/pgtable-nopmd.h> /* * We only use two ring levels, user and kernel space. */ #ifdef CONFIG_MMU #define USER_RING 1 /* user ring level */ #else #define USER_RING 0 #endif #define KERNEL_RING 0 /* kernel ring level */ /* * The Xtensa architecture port of Linux has a two-level page table system, * i.e. the logical three-level Linux page table layout is folded. * Each task has the following memory page tables: * * PGD table (page directory), ie. 3rd-level page table: * One page (4 kB) of 1024 (PTRS_PER_PGD) pointers to PTE tables * (Architectures that don't have the PMD folded point to the PMD tables) * * The pointer to the PGD table for a given task can be retrieved from * the task structure (struct task_struct*) t, e.g. current(): * (t->mm ? t->mm : t->active_mm)->pgd * * PMD tables (page middle-directory), ie. 2nd-level page tables: * Absent for the Xtensa architecture (folded, PTRS_PER_PMD == 1). * * PTE tables (page table entry), ie. 1st-level page tables: * One page (4 kB) of 1024 (PTRS_PER_PTE) PTEs with a special PTE * invalid_pte_table for absent mappings. * * The individual pages are 4 kB big with special pages for the empty_zero_page. */ #define PGDIR_SHIFT 22 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE-1)) /* * Entries per page directory level: we use two-level, so * we don't really have any PMD directory physically. */ #define PTRS_PER_PTE 1024 #define PTRS_PER_PTE_SHIFT 10 #define PTRS_PER_PGD 1024 #define PGD_ORDER 0 #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) #define FIRST_USER_ADDRESS 0UL #define FIRST_USER_PGD_NR (FIRST_USER_ADDRESS >> PGDIR_SHIFT) #ifdef CONFIG_MMU /* * Virtual memory area. We keep a distance to other memory regions to be * on the safe side. We also use this area for cache aliasing. */ #define VMALLOC_START (XCHAL_KSEG_CACHED_VADDR - 0x10000000) #define VMALLOC_END (VMALLOC_START + 0x07FEFFFF) #define TLBTEMP_BASE_1 (VMALLOC_END + 1) #define TLBTEMP_BASE_2 (TLBTEMP_BASE_1 + DCACHE_WAY_SIZE) #if 2 * DCACHE_WAY_SIZE > ICACHE_WAY_SIZE #define TLBTEMP_SIZE (2 * DCACHE_WAY_SIZE) #else #define TLBTEMP_SIZE ICACHE_WAY_SIZE #endif #else #define VMALLOC_START __XTENSA_UL_CONST(0) #define VMALLOC_END __XTENSA_UL_CONST(0xffffffff) #endif /* * For the Xtensa architecture, the PTE layout is as follows: * * 31------12 11 10-9 8-6 5-4 3-2 1-0 * +-----------------------------------------+ * | | Software | HARDWARE | * | PPN | ADW | RI |Attribute| * +-----------------------------------------+ * pte_none | MBZ | 01 | 11 | 00 | * +-----------------------------------------+ * present | PPN | 0 | 00 | ADW | RI | CA | wx | * +- - - - - - - - - - - - - - - - - - - - -+ * (PAGE_NONE)| PPN | 0 | 00 | ADW | 01 | 11 | 11 | * +-----------------------------------------+ * swap | index | type | 01 | 11 | 00 | * +-----------------------------------------+ * * For T1050 hardware and earlier the layout differs for present and (PAGE_NONE) * +-----------------------------------------+ * present | PPN | 0 | 00 | ADW | RI | CA | w1 | * +-----------------------------------------+ * (PAGE_NONE)| PPN | 0 | 00 | ADW | 01 | 01 | 00 | * +-----------------------------------------+ * * Legend: * PPN Physical Page Number * ADW software: accessed (young) / dirty / writable * RI ring (0=privileged, 1=user, 2 and 3 are unused) * CA cache attribute: 00 bypass, 01 writeback, 10 writethrough * (11 is invalid and used to mark pages that are not present) * w page is writable (hw) * x page is executable (hw) * index swap offset / PAGE_SIZE (bit 11-31: 21 bits -> 8 GB) * (note that the index is always non-zero) * type swap type (5 bits -> 32 types) * * Notes: * - (PROT_NONE) is a special case of 'present' but causes an exception for * any access (read, write, and execute). * - 'multihit-exception' has the highest priority of all MMU exceptions, * so the ring must be set to 'RING_USER' even for 'non-present' pages. * - on older hardware, the exectuable flag was not supported and * used as a 'valid' flag, so it needs to be always set. * - we need to keep track of certain flags in software (dirty and young) * to do this, we use write exceptions and have a separate software w-flag. * - attribute value 1101 (and 1111 on T1050 and earlier) is reserved */ #define _PAGE_ATTRIB_MASK 0xf #define _PAGE_HW_EXEC (1<<0) /* hardware: page is executable */ #define _PAGE_HW_WRITE (1<<1) /* hardware: page is writable */ #define _PAGE_CA_BYPASS (0<<2) /* bypass, non-speculative */ #define _PAGE_CA_WB (1<<2) /* write-back */ #define _PAGE_CA_WT (2<<2) /* write-through */ #define _PAGE_CA_MASK (3<<2) #define _PAGE_CA_INVALID (3<<2) /* We use invalid attribute values to distinguish special pte entries */ #if XCHAL_HW_VERSION_MAJOR < 2000 #define _PAGE_HW_VALID 0x01 /* older HW needed this bit set */ #define _PAGE_NONE 0x04 #else #define _PAGE_HW_VALID 0x00 #define _PAGE_NONE 0x0f #endif #define _PAGE_USER (1<<4) /* user access (ring=1) */ /* Software */ #define _PAGE_WRITABLE_BIT 6 #define _PAGE_WRITABLE (1<<6) /* software: page writable */ #define _PAGE_DIRTY (1<<7) /* software: page dirty */ #define _PAGE_ACCESSED (1<<8) /* software: page accessed (read) */ #ifdef CONFIG_MMU #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) #define _PAGE_PRESENT (_PAGE_HW_VALID | _PAGE_CA_WB | _PAGE_ACCESSED) #define PAGE_NONE __pgprot(_PAGE_NONE | _PAGE_USER) #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER) #define PAGE_COPY_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_HW_EXEC) #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER) #define PAGE_READONLY_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_HW_EXEC) #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE) #define PAGE_SHARED_EXEC \ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE | _PAGE_HW_EXEC) #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_HW_WRITE) #define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT) #define PAGE_KERNEL_EXEC __pgprot(_PAGE_PRESENT|_PAGE_HW_WRITE|_PAGE_HW_EXEC) #if (DCACHE_WAY_SIZE > PAGE_SIZE) # define _PAGE_DIRECTORY (_PAGE_HW_VALID | _PAGE_ACCESSED | _PAGE_CA_BYPASS) #else # define _PAGE_DIRECTORY (_PAGE_HW_VALID | _PAGE_ACCESSED | _PAGE_CA_WB) #endif #else /* no mmu */ # define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) # define PAGE_NONE __pgprot(0) # define PAGE_SHARED __pgprot(0) # define PAGE_COPY __pgprot(0) # define PAGE_READONLY __pgprot(0) # define PAGE_KERNEL __pgprot(0) #endif /* * On certain configurations of Xtensa MMUs (eg. the initial Linux config), * the MMU can't do page protection for execute, and considers that the same as * read. Also, write permissions may imply read permissions. * What follows is the closest we can get by reasonable means.. * See linux/mm/mmap.c for protection_map[] array that uses these definitions. */ #define __P000 PAGE_NONE /* private --- */ #define __P001 PAGE_READONLY /* private --r */ #define __P010 PAGE_COPY /* private -w- */ #define __P011 PAGE_COPY /* private -wr */ #define __P100 PAGE_READONLY_EXEC /* private x-- */ #define __P101 PAGE_READONLY_EXEC /* private x-r */ #define __P110 PAGE_COPY_EXEC /* private xw- */ #define __P111 PAGE_COPY_EXEC /* private xwr */ #define __S000 PAGE_NONE /* shared --- */ #define __S001 PAGE_READONLY /* shared --r */ #define __S010 PAGE_SHARED /* shared -w- */ #define __S011 PAGE_SHARED /* shared -wr */ #define __S100 PAGE_READONLY_EXEC /* shared x-- */ #define __S101 PAGE_READONLY_EXEC /* shared x-r */ #define __S110 PAGE_SHARED_EXEC /* shared xw- */ #define __S111 PAGE_SHARED_EXEC /* shared xwr */ #ifndef __ASSEMBLY__ #define pte_ERROR(e) \ printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e)) #define pgd_ERROR(e) \ printk("%s:%d: bad pgd entry %08lx.\n", __FILE__, __LINE__, pgd_val(e)) extern unsigned long empty_zero_page[1024]; #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) #ifdef CONFIG_MMU extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)]; extern void paging_init(void); #else # define swapper_pg_dir NULL static inline void paging_init(void) { } #endif static inline void pgtable_cache_init(void) { } /* * The pmd contains the kernel virtual address of the pte page. */ #define pmd_page_vaddr(pmd) ((unsigned long)(pmd_val(pmd) & PAGE_MASK)) #define pmd_page(pmd) virt_to_page(pmd_val(pmd)) /* * pte status. */ # define pte_none(pte) (pte_val(pte) == (_PAGE_CA_INVALID | _PAGE_USER)) #if XCHAL_HW_VERSION_MAJOR < 2000 # define pte_present(pte) ((pte_val(pte) & _PAGE_CA_MASK) != _PAGE_CA_INVALID) #else # define pte_present(pte) \ (((pte_val(pte) & _PAGE_CA_MASK) != _PAGE_CA_INVALID) \ || ((pte_val(pte) & _PAGE_ATTRIB_MASK) == _PAGE_NONE)) #endif #define pte_clear(mm,addr,ptep) \ do { update_pte(ptep, __pte(_PAGE_CA_INVALID | _PAGE_USER)); } while (0) #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd) & PAGE_MASK) #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK) #define pmd_clear(pmdp) do { set_pmd(pmdp, __pmd(0)); } while (0) static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITABLE; } static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } static inline int pte_special(pte_t pte) { return 0; } static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~(_PAGE_WRITABLE | _PAGE_HW_WRITE); return pte; } static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HW_WRITE); return pte; } static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; } static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; } static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_WRITABLE; return pte; } static inline pte_t pte_mkspecial(pte_t pte) { return pte; } #define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) & ~_PAGE_CA_MASK)) /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */ #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) #define pte_same(a,b) (pte_val(a) == pte_val(b)) #define pte_page(x) pfn_to_page(pte_pfn(x)) #define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)) #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); } /* * Certain architectures need to do special things when pte's * within a page table are directly modified. Thus, the following * hook is made available. */ static inline void update_pte(pte_t *ptep, pte_t pteval) { *ptep = pteval; #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK __asm__ __volatile__ ("dhwb %0, 0" :: "a" (ptep)); #endif } struct mm_struct; static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval) { update_pte(ptep, pteval); } static inline void set_pte(pte_t *ptep, pte_t pteval) { update_pte(ptep, pteval); } static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval) { *pmdp = pmdval; } struct vm_area_struct; static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { pte_t pte = *ptep; if (!pte_young(pte)) return 0; update_pte(ptep, pte_mkold(pte)); return 1; } static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_t pte = *ptep; pte_clear(mm, addr, ptep); return pte; } static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_t pte = *ptep; update_pte(ptep, pte_wrprotect(pte)); } /* to find an entry in a kernel page-table-directory */ #define pgd_offset_k(address) pgd_offset(&init_mm, address) /* to find an entry in a page-table-directory */ #define pgd_offset(mm,address) ((mm)->pgd + pgd_index(address)) #define pgd_index(address) ((address) >> PGDIR_SHIFT) /* Find an entry in the second-level page table.. */ #define pmd_offset(dir,address) ((pmd_t*)(dir)) /* Find an entry in the third-level page table.. */ #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) #define pte_offset_kernel(dir,addr) \ ((pte_t*) pmd_page_vaddr(*(dir)) + pte_index(addr)) #define pte_offset_map(dir,addr) pte_offset_kernel((dir),(addr)) #define pte_unmap(pte) do { } while (0) /* * Encode and decode a swap and file entry. */ #define SWP_TYPE_BITS 5 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS) #define __swp_type(entry) (((entry).val >> 6) & 0x1f) #define __swp_offset(entry) ((entry).val >> 11) #define __swp_entry(type,offs) \ ((swp_entry_t){((type) << 6) | ((offs) << 11) | \ _PAGE_CA_INVALID | _PAGE_USER}) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) #endif /* !defined (__ASSEMBLY__) */ #ifdef __ASSEMBLY__ /* Assembly macro _PGD_INDEX is the same as C pgd_index(unsigned long), * _PGD_OFFSET as C pgd_offset(struct mm_struct*, unsigned long), * _PMD_OFFSET as C pmd_offset(pgd_t*, unsigned long) * _PTE_OFFSET as C pte_offset(pmd_t*, unsigned long) * * Note: We require an additional temporary register which can be the same as * the register that holds the address. * * ((pte_t*) ((unsigned long)(pmd_val(*pmd) & PAGE_MASK)) + pte_index(addr)) * */ #define _PGD_INDEX(rt,rs) extui rt, rs, PGDIR_SHIFT, 32-PGDIR_SHIFT #define _PTE_INDEX(rt,rs) extui rt, rs, PAGE_SHIFT, PTRS_PER_PTE_SHIFT #define _PGD_OFFSET(mm,adr,tmp) l32i mm, mm, MM_PGD; \ _PGD_INDEX(tmp, adr); \ addx4 mm, tmp, mm #define _PTE_OFFSET(pmd,adr,tmp) _PTE_INDEX(tmp, adr); \ srli pmd, pmd, PAGE_SHIFT; \ slli pmd, pmd, PAGE_SHIFT; \ addx4 pmd, tmp, pmd #else #define kern_addr_valid(addr) (1) extern void update_mmu_cache(struct vm_area_struct * vma, unsigned long address, pte_t *ptep); typedef pte_t *pte_addr_t; #endif /* !defined (__ASSEMBLY__) */ #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG #define __HAVE_ARCH_PTEP_GET_AND_CLEAR #define __HAVE_ARCH_PTEP_SET_WRPROTECT #define __HAVE_ARCH_PTEP_MKDIRTY #define __HAVE_ARCH_PTE_SAME /* We provide our own get_unmapped_area to cope with * SHM area cache aliasing for userland. */ #define HAVE_ARCH_UNMAPPED_AREA #include <asm-generic/pgtable.h> #endif /* _XTENSA_PGTABLE_H */