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Diffstat (limited to 'arch/xtensa/include/asm/pgtable.h')
| -rw-r--r-- | arch/xtensa/include/asm/pgtable.h | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h new file mode 100644 index 000000000..29cfe421c --- /dev/null +++ b/arch/xtensa/include/asm/pgtable.h @@ -0,0 +1,454 @@ +/* + * 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 */ |