/* * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * * 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. * * vineetg: May 2011 * -Folded PAGE_PRESENT (used by VM) and PAGE_VALID (used by MMU) into 1. * They are semantically the same although in different contexts * VALID marks a TLB entry exists and it will only happen if PRESENT * - Utilise some unused free bits to confine PTE flags to 12 bits * This is a must for 4k pg-sz * * vineetg: Mar 2011 - changes to accomodate MMU TLB Page Descriptor mods * -TLB Locking never really existed, except for initial specs * -SILENT_xxx not needed for our port * -Per my request, MMU V3 changes the layout of some of the bits * to avoid a few shifts in TLB Miss handlers. * * vineetg: April 2010 * -PGD entry no longer contains any flags. If empty it is 0, otherwise has * Pg-Tbl ptr. Thus pmd_present(), pmd_valid(), pmd_set( ) become simpler * * vineetg: April 2010 * -Switched form 8:11:13 split for page table lookup to 11:8:13 * -this speeds up page table allocation itself as we now have to memset 1K * instead of 8k per page table. * -TODO: Right now page table alloc is 8K and rest 7K is unused * need to optimise it * * Amit Bhor, Sameer Dhavale: Codito Technologies 2004 */ #ifndef _ASM_ARC_PGTABLE_H #define _ASM_ARC_PGTABLE_H #include #include #include /************************************************************************** * Page Table Flags * * ARC700 MMU only deals with softare managed TLB entries. * Page Tables are purely for Linux VM's consumption and the bits below are * suited to that (uniqueness). Hence some are not implemented in the TLB and * some have different value in TLB. * e.g. MMU v2: K_READ bit is 8 and so is GLOBAL (possible becoz they live in * seperate PD0 and PD1, which combined forms a translation entry) * while for PTE perspective, they are 8 and 9 respectively * with MMU v3: Most bits (except SHARED) represent the exact hardware pos * (saves some bit shift ops in TLB Miss hdlrs) */ #if (CONFIG_ARC_MMU_VER <= 2) #define _PAGE_ACCESSED (1<<1) /* Page is accessed (S) */ #define _PAGE_CACHEABLE (1<<2) /* Page is cached (H) */ #define _PAGE_EXECUTE (1<<3) /* Page has user execute perm (H) */ #define _PAGE_WRITE (1<<4) /* Page has user write perm (H) */ #define _PAGE_READ (1<<5) /* Page has user read perm (H) */ #define _PAGE_MODIFIED (1<<6) /* Page modified (dirty) (S) */ #define _PAGE_FILE (1<<7) /* page cache/ swap (S) */ #define _PAGE_GLOBAL (1<<8) /* Page is global (H) */ #define _PAGE_PRESENT (1<<10) /* TLB entry is valid (H) */ #else /* MMU v3 onwards */ #define _PAGE_CACHEABLE (1<<0) /* Page is cached (H) */ #define _PAGE_EXECUTE (1<<1) /* Page has user execute perm (H) */ #define _PAGE_WRITE (1<<2) /* Page has user write perm (H) */ #define _PAGE_READ (1<<3) /* Page has user read perm (H) */ #define _PAGE_ACCESSED (1<<4) /* Page is accessed (S) */ #define _PAGE_MODIFIED (1<<5) /* Page modified (dirty) (S) */ #define _PAGE_FILE (1<<6) /* page cache/ swap (S) */ #define _PAGE_GLOBAL (1<<8) /* Page is global (H) */ #define _PAGE_PRESENT (1<<9) /* TLB entry is valid (H) */ #define _PAGE_SHARED_CODE (1<<11) /* Shared Code page with cmn vaddr usable for shared TLB entries (H) */ #endif /* vmalloc permissions */ #define _K_PAGE_PERMS (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ | \ _PAGE_GLOBAL | _PAGE_PRESENT) #ifdef CONFIG_ARC_CACHE_PAGES #define _PAGE_DEF_CACHEABLE _PAGE_CACHEABLE #else #define _PAGE_DEF_CACHEABLE (0) #endif /* Helper for every "user" page * -kernel can R/W/X * -by default cached, unless config otherwise * -present in memory */ #define ___DEF (_PAGE_PRESENT | _PAGE_DEF_CACHEABLE) /* Set of bits not changed in pte_modify */ #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED) /* More Abbrevaited helpers */ #define PAGE_U_NONE __pgprot(___DEF) #define PAGE_U_R __pgprot(___DEF | _PAGE_READ) #define PAGE_U_W_R __pgprot(___DEF | _PAGE_READ | _PAGE_WRITE) #define PAGE_U_X_R __pgprot(___DEF | _PAGE_READ | _PAGE_EXECUTE) #define PAGE_U_X_W_R __pgprot(___DEF | _PAGE_READ | _PAGE_WRITE | \ _PAGE_EXECUTE) #define PAGE_SHARED PAGE_U_W_R /* While kernel runs out of unstranslated space, vmalloc/modules use a chunk of * user vaddr space - visible in all addr spaces, but kernel mode only * Thus Global, all-kernel-access, no-user-access, cached */ #define PAGE_KERNEL __pgprot(_K_PAGE_PERMS | _PAGE_DEF_CACHEABLE) /* ioremap */ #define PAGE_KERNEL_NO_CACHE __pgprot(_K_PAGE_PERMS) /* Masks for actual TLB "PD"s */ #define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT) #define PTE_BITS_RWX (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ) #define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE) /************************************************************************** * Mapping of vm_flags (Generic VM) to PTE flags (arch specific) * * Certain cases have 1:1 mapping * e.g. __P101 means VM_READ, VM_EXEC and !VM_SHARED * which directly corresponds to PAGE_U_X_R * * Other rules which cause the divergence from 1:1 mapping * * 1. Although ARC700 can do exclusive execute/write protection (meaning R * can be tracked independet of X/W unlike some other CPUs), still to * keep things consistent with other archs: * -Write implies Read: W => R * -Execute implies Read: X => R * * 2. Pvt Writable doesn't have Write Enabled initially: Pvt-W => !W * This is to enable COW mechanism */ /* xwr */ #define __P000 PAGE_U_NONE #define __P001 PAGE_U_R #define __P010 PAGE_U_R /* Pvt-W => !W */ #define __P011 PAGE_U_R /* Pvt-W => !W */ #define __P100 PAGE_U_X_R /* X => R */ #define __P101 PAGE_U_X_R #define __P110 PAGE_U_X_R /* Pvt-W => !W and X => R */ #define __P111 PAGE_U_X_R /* Pvt-W => !W */ #define __S000 PAGE_U_NONE #define __S001 PAGE_U_R #define __S010 PAGE_U_W_R /* W => R */ #define __S011 PAGE_U_W_R #define __S100 PAGE_U_X_R /* X => R */ #define __S101 PAGE_U_X_R #define __S110 PAGE_U_X_W_R /* X => R */ #define __S111 PAGE_U_X_W_R /**************************************************************** * Page Table Lookup split * * We implement 2 tier paging and since this is all software, we are free * to customize the span of a PGD / PTE entry to suit us * * 32 bit virtual address * ------------------------------------------------------- * | BITS_FOR_PGD | BITS_FOR_PTE | BITS_IN_PAGE | * ------------------------------------------------------- * | | | * | | --> off in page frame * | | * | ---> index into Page Table * | * ----> index into Page Directory */ #define BITS_IN_PAGE PAGE_SHIFT /* Optimal Sizing of Pg Tbl - based on MMU page size */ #if defined(CONFIG_ARC_PAGE_SIZE_8K) #define BITS_FOR_PTE 8 #elif defined(CONFIG_ARC_PAGE_SIZE_16K) #define BITS_FOR_PTE 8 #elif defined(CONFIG_ARC_PAGE_SIZE_4K) #define BITS_FOR_PTE 9 #endif #define BITS_FOR_PGD (32 - BITS_FOR_PTE - BITS_IN_PAGE) #define PGDIR_SHIFT (BITS_FOR_PTE + BITS_IN_PAGE) #define PGDIR_SIZE (1UL << PGDIR_SHIFT) /* vaddr span, not PDG sz */ #define PGDIR_MASK (~(PGDIR_SIZE-1)) #ifdef __ASSEMBLY__ #define PTRS_PER_PTE (1 << BITS_FOR_PTE) #define PTRS_PER_PGD (1 << BITS_FOR_PGD) #else #define PTRS_PER_PTE (1UL << BITS_FOR_PTE) #define PTRS_PER_PGD (1UL << BITS_FOR_PGD) #endif /* * Number of entries a user land program use. * TASK_SIZE is the maximum vaddr that can be used by a userland program. */ #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) /* * No special requirements for lowest virtual address we permit any user space * mapping to be mapped at. */ #define FIRST_USER_ADDRESS 0 /**************************************************************** * Bucket load of VM Helpers */ #ifndef __ASSEMBLY__ #define pte_ERROR(e) \ pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e)) #define pgd_ERROR(e) \ pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) /* the zero page used for uninitialized and anonymous pages */ extern char empty_zero_page[PAGE_SIZE]; #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) #define pte_unmap(pte) do { } while (0) #define pte_unmap_nested(pte) do { } while (0) #define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) /* find the page descriptor of the Page Tbl ref by PMD entry */ #define pmd_page(pmd) virt_to_page(pmd_val(pmd) & PAGE_MASK) /* find the logical addr (phy for ARC) of the Page Tbl ref by PMD entry */ #define pmd_page_vaddr(pmd) (pmd_val(pmd) & PAGE_MASK) /* In a 2 level sys, setup the PGD entry with PTE value */ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) { pmd_val(*pmdp) = (unsigned long)ptep; } #define pte_none(x) (!pte_val(x)) #define pte_present(x) (pte_val(x) & _PAGE_PRESENT) #define pte_clear(mm, addr, ptep) set_pte_at(mm, addr, ptep, __pte(0)) #define pmd_none(x) (!pmd_val(x)) #define pmd_bad(x) ((pmd_val(x) & ~PAGE_MASK)) #define pmd_present(x) (pmd_val(x)) #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) #define pte_page(x) (mem_map + \ (unsigned long)(((pte_val(x) - CONFIG_LINUX_LINK_BASE) >> \ PAGE_SHIFT))) #define mk_pte(page, pgprot) \ ({ \ pte_t pte; \ pte_val(pte) = __pa(page_address(page)) + pgprot_val(pgprot); \ pte; \ }) /* TBD: Non linear mapping stuff */ static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; } #define PTE_FILE_MAX_BITS 30 #define pgoff_to_pte(x) __pte(x) #define pte_to_pgoff(x) (pte_val(x) >> 2) #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) #define pfn_pte(pfn, prot) (__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))) #define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) /* * pte_offset gets a @ptr to PMD entry (PGD in our 2-tier paging system) * and returns ptr to PTE entry corresponding to @addr */ #define pte_offset(dir, addr) ((pte_t *)(pmd_page_vaddr(*dir)) +\ __pte_index(addr)) /* No mapping of Page Tables in high mem etc, so following same as above */ #define pte_offset_kernel(dir, addr) pte_offset(dir, addr) #define pte_offset_map(dir, addr) pte_offset(dir, addr) /* Zoo of pte_xxx function */ #define pte_read(pte) (pte_val(pte) & _PAGE_READ) #define pte_write(pte) (pte_val(pte) & _PAGE_WRITE) #define pte_dirty(pte) (pte_val(pte) & _PAGE_MODIFIED) #define pte_young(pte) (pte_val(pte) & _PAGE_ACCESSED) #define pte_special(pte) (0) #define PTE_BIT_FUNC(fn, op) \ static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } PTE_BIT_FUNC(wrprotect, &= ~(_PAGE_WRITE)); PTE_BIT_FUNC(mkwrite, |= (_PAGE_WRITE)); PTE_BIT_FUNC(mkclean, &= ~(_PAGE_MODIFIED)); PTE_BIT_FUNC(mkdirty, |= (_PAGE_MODIFIED)); PTE_BIT_FUNC(mkold, &= ~(_PAGE_ACCESSED)); PTE_BIT_FUNC(mkyoung, |= (_PAGE_ACCESSED)); PTE_BIT_FUNC(exprotect, &= ~(_PAGE_EXECUTE)); PTE_BIT_FUNC(mkexec, |= (_PAGE_EXECUTE)); static inline pte_t pte_mkspecial(pte_t pte) { return pte; } static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); } /* Macro to mark a page protection as uncacheable */ #define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) & ~_PAGE_CACHEABLE)) static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval) { set_pte(ptep, pteval); } /* * All kernel related VM pages are in init's mm. */ #define pgd_offset_k(address) pgd_offset(&init_mm, address) #define pgd_index(addr) ((addr) >> PGDIR_SHIFT) #define pgd_offset(mm, addr) (((mm)->pgd)+pgd_index(addr)) /* * Macro to quickly access the PGD entry, utlising the fact that some * arch may cache the pointer to Page Directory of "current" task * in a MMU register * * Thus task->mm->pgd (3 pointer dereferences, cache misses etc simply * becomes read a register * * ********CAUTION*******: * Kernel code might be dealing with some mm_struct of NON "current" * Thus use this macro only when you are certain that "current" is current * e.g. when dealing with signal frame setup code etc */ #ifndef CONFIG_SMP #define pgd_offset_fast(mm, addr) \ ({ \ pgd_t *pgd_base = (pgd_t *) read_aux_reg(ARC_REG_SCRATCH_DATA0); \ pgd_base + pgd_index(addr); \ }) #else #define pgd_offset_fast(mm, addr) pgd_offset(mm, addr) #endif extern void paging_init(void); extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE); void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep); /* Encode swap {type,off} tuple into PTE * We reserve 13 bits for 5-bit @type, keeping bits 12-5 zero, ensuring that * both PAGE_FILE and PAGE_PRESENT are zero in a PTE holding swap "identifier" */ #define __swp_entry(type, off) ((swp_entry_t) { \ ((type) & 0x1f) | ((off) << 13) }) /* Decode a PTE containing swap "identifier "into constituents */ #define __swp_type(pte_lookalike) (((pte_lookalike).val) & 0x1f) #define __swp_offset(pte_lookalike) ((pte_lookalike).val << 13) /* NOPs, to keep generic kernel happy */ #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) #define kern_addr_valid(addr) (1) /* * remap a physical page `pfn' of size `size' with page protection `prot' * into virtual address `from' */ #include /* to cope with aliasing VIPT cache */ #define HAVE_ARCH_UNMAPPED_AREA /* * No page table caches to initialise */ #define pgtable_cache_init() do { } while (0) #endif /* __ASSEMBLY__ */ #endif