| /* |
| * 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 accommodate 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 <linux/const.h> |
| #define __ARCH_USE_5LEVEL_HACK |
| #include <asm-generic/pgtable-nopmd.h> |
| #include <asm/page.h> |
| #include <asm/mmu.h> /* to propagate CONFIG_ARC_MMU_VER <n> */ |
| |
| /************************************************************************** |
| * 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 because 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_DIRTY (1<<6) /* Page modified (dirty) (S) */ |
| #define _PAGE_SPECIAL (1<<7) |
| #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_DIRTY (1<<5) /* Page modified (dirty) (S) */ |
| #define _PAGE_SPECIAL (1<<6) |
| |
| #if (CONFIG_ARC_MMU_VER >= 4) |
| #define _PAGE_WTHRU (1<<7) /* Page cache mode write-thru (H) */ |
| #endif |
| |
| #define _PAGE_GLOBAL (1<<8) /* Page is global (H) */ |
| #define _PAGE_PRESENT (1<<9) /* TLB entry is valid (H) */ |
| |
| #if (CONFIG_ARC_MMU_VER >= 4) |
| #define _PAGE_HW_SZ (1<<10) /* Page Size indicator (H): 0 normal, 1 super */ |
| #endif |
| |
| #define _PAGE_SHARED_CODE (1<<11) /* Shared Code page with cmn vaddr |
| usable for shared TLB entries (H) */ |
| |
| #define _PAGE_UNUSED_BIT (1<<12) |
| #endif |
| |
| /* vmalloc permissions */ |
| #define _K_PAGE_PERMS (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ | \ |
| _PAGE_GLOBAL | _PAGE_PRESENT) |
| |
| #ifndef CONFIG_ARC_CACHE_PAGES |
| #undef _PAGE_CACHEABLE |
| #define _PAGE_CACHEABLE 0 |
| #endif |
| |
| #ifndef _PAGE_HW_SZ |
| #define _PAGE_HW_SZ 0 |
| #endif |
| |
| /* Defaults for every user page */ |
| #define ___DEF (_PAGE_PRESENT | _PAGE_CACHEABLE) |
| |
| /* Set of bits not changed in pte_modify */ |
| #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_SPECIAL) |
| |
| /* 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_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 | _PAGE_HW_SZ) |
| #define PTE_BITS_RWX (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ) |
| |
| #ifdef CONFIG_ARC_HAS_PAE40 |
| #define PTE_BITS_NON_RWX_IN_PD1 (0xff00000000 | PAGE_MASK | _PAGE_CACHEABLE) |
| #else |
| #define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE) |
| #endif |
| |
| /************************************************************************** |
| * 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 |
| |
| /**************************************************************** |
| * 2 tier (PGD:PTE) software page walker |
| * |
| * [31] 32 bit virtual address [0] |
| * ------------------------------------------------------- |
| * | | <------------ PGDIR_SHIFT ----------> | |
| * | | | |
| * | BITS_FOR_PGD | BITS_FOR_PTE | <-- PAGE_SHIFT --> | |
| * ------------------------------------------------------- |
| * | | | |
| * | | --> off in page frame |
| * | ---> index into Page Table |
| * ----> index into Page Directory |
| * |
| * In a single page size configuration, only PAGE_SHIFT is fixed |
| * So both PGD and PTE sizing can be tweaked |
| * e.g. 8K page (PAGE_SHIFT 13) can have |
| * - PGDIR_SHIFT 21 -> 11:8:13 address split |
| * - PGDIR_SHIFT 24 -> 8:11:13 address split |
| * |
| * If Super Page is configured, PGDIR_SHIFT becomes fixed too, |
| * so the sizing flexibility is gone. |
| */ |
| |
| #if defined(CONFIG_ARC_HUGEPAGE_16M) |
| #define PGDIR_SHIFT 24 |
| #elif defined(CONFIG_ARC_HUGEPAGE_2M) |
| #define PGDIR_SHIFT 21 |
| #else |
| /* |
| * Only Normal page support so "hackable" (see comment above) |
| * Default value provides 11:8:13 (8K), 11:9:12 (4K) |
| */ |
| #define PGDIR_SHIFT 21 |
| #endif |
| |
| #define BITS_FOR_PTE (PGDIR_SHIFT - PAGE_SHIFT) |
| #define BITS_FOR_PGD (32 - PGDIR_SHIFT) |
| |
| #define PGDIR_SIZE _BITUL(PGDIR_SHIFT) /* vaddr span, not PDG sz */ |
| #define PGDIR_MASK (~(PGDIR_SIZE-1)) |
| |
| #define PTRS_PER_PTE _BITUL(BITS_FOR_PTE) |
| #define PTRS_PER_PGD _BITUL(BITS_FOR_PGD) |
| |
| /* |
| * 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 0UL |
| |
| |
| /**************************************************************** |
| * 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(pte) pfn_to_page(pte_pfn(pte)) |
| #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) |
| #define pfn_pte(pfn, prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot)) |
| |
| /* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/ |
| #define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) |
| #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_DIRTY) |
| #define pte_young(pte) (pte_val(pte) & _PAGE_ACCESSED) |
| #define pte_special(pte) (pte_val(pte) & _PAGE_SPECIAL) |
| |
| #define PTE_BIT_FUNC(fn, op) \ |
| static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; } |
| |
| PTE_BIT_FUNC(mknotpresent, &= ~(_PAGE_PRESENT)); |
| PTE_BIT_FUNC(wrprotect, &= ~(_PAGE_WRITE)); |
| PTE_BIT_FUNC(mkwrite, |= (_PAGE_WRITE)); |
| PTE_BIT_FUNC(mkclean, &= ~(_PAGE_DIRTY)); |
| PTE_BIT_FUNC(mkdirty, |= (_PAGE_DIRTY)); |
| PTE_BIT_FUNC(mkold, &= ~(_PAGE_ACCESSED)); |
| PTE_BIT_FUNC(mkyoung, |= (_PAGE_ACCESSED)); |
| PTE_BIT_FUNC(exprotect, &= ~(_PAGE_EXECUTE)); |
| PTE_BIT_FUNC(mkexec, |= (_PAGE_EXECUTE)); |
| PTE_BIT_FUNC(mkspecial, |= (_PAGE_SPECIAL)); |
| PTE_BIT_FUNC(mkhuge, |= (_PAGE_HW_SZ)); |
| |
| #define __HAVE_ARCH_PTE_SPECIAL |
| |
| 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 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 |
| * PAGE_PRESENT is 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' |
| */ |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| #include <asm/hugepage.h> |
| #endif |
| |
| #include <asm-generic/pgtable.h> |
| |
| /* 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 |
