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Diffstat (limited to 'kernel/arch/arc/include/asm/pgtable.h')
| -rw-r--r-- | kernel/arch/arc/include/asm/pgtable.h | 388 |
1 files changed, 388 insertions, 0 deletions
diff --git a/kernel/arch/arc/include/asm/pgtable.h b/kernel/arch/arc/include/asm/pgtable.h new file mode 100644 index 000000000..9615fe170 --- /dev/null +++ b/kernel/arch/arc/include/asm/pgtable.h @@ -0,0 +1,388 @@ +/* + * 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 <asm/page.h> +#include <asm/mmu.h> +#include <asm-generic/pgtable-nopmd.h> + +/************************************************************************** + * 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_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_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 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(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; \ +}) + +#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 + * 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' + */ +#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 |