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Diffstat (limited to 'arch/arc/include/asm/pgtable.h')
| -rw-r--r-- | arch/arc/include/asm/pgtable.h | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h new file mode 100644 index 000000000..5878846f0 --- /dev/null +++ b/arch/arc/include/asm/pgtable.h @@ -0,0 +1,372 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * 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/bits.h> +#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_PHYS | _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) + +#define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK_PHYS | _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 + +/**************************************************************** + * 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 BIT(PGDIR_SHIFT) /* vaddr span, not PDG sz */ +#define PGDIR_MASK (~(PGDIR_SIZE-1)) + +#define PTRS_PER_PTE BIT(BITS_FOR_PTE) +#define PTRS_PER_PGD BIT(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 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_leaf(x) (pmd_val(x) & _PAGE_HW_SZ) +#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) + +/* 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)); + +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); +} + +/* + * 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 + */ +#ifdef ARC_USE_SCRATCH_REG +#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 + +/* to cope with aliasing VIPT cache */ +#define HAVE_ARCH_UNMAPPED_AREA + +#endif /* __ASSEMBLY__ */ + +#endif |