diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/powerpc/mm/pgtable.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/powerpc/mm/pgtable.c | 242 |
1 files changed, 0 insertions, 242 deletions
diff --git a/ANDROID_3.4.5/arch/powerpc/mm/pgtable.c b/ANDROID_3.4.5/arch/powerpc/mm/pgtable.c deleted file mode 100644 index 214130a4..00000000 --- a/ANDROID_3.4.5/arch/powerpc/mm/pgtable.c +++ /dev/null @@ -1,242 +0,0 @@ -/* - * This file contains common routines for dealing with free of page tables - * Along with common page table handling code - * - * Derived from arch/powerpc/mm/tlb_64.c: - * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) - * - * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) - * and Cort Dougan (PReP) (cort@cs.nmt.edu) - * Copyright (C) 1996 Paul Mackerras - * - * Derived from "arch/i386/mm/init.c" - * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds - * - * Dave Engebretsen <engebret@us.ibm.com> - * Rework for PPC64 port. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#include <linux/kernel.h> -#include <linux/gfp.h> -#include <linux/mm.h> -#include <linux/init.h> -#include <linux/percpu.h> -#include <linux/hardirq.h> -#include <linux/hugetlb.h> -#include <asm/pgalloc.h> -#include <asm/tlbflush.h> -#include <asm/tlb.h> - -#include "mmu_decl.h" - -static inline int is_exec_fault(void) -{ - return current->thread.regs && TRAP(current->thread.regs) == 0x400; -} - -/* We only try to do i/d cache coherency on stuff that looks like - * reasonably "normal" PTEs. We currently require a PTE to be present - * and we avoid _PAGE_SPECIAL and _PAGE_NO_CACHE. We also only do that - * on userspace PTEs - */ -static inline int pte_looks_normal(pte_t pte) -{ - return (pte_val(pte) & - (_PAGE_PRESENT | _PAGE_SPECIAL | _PAGE_NO_CACHE | _PAGE_USER)) == - (_PAGE_PRESENT | _PAGE_USER); -} - -struct page * maybe_pte_to_page(pte_t pte) -{ - unsigned long pfn = pte_pfn(pte); - struct page *page; - - if (unlikely(!pfn_valid(pfn))) - return NULL; - page = pfn_to_page(pfn); - if (PageReserved(page)) - return NULL; - return page; -} - -#if defined(CONFIG_PPC_STD_MMU) || _PAGE_EXEC == 0 - -/* Server-style MMU handles coherency when hashing if HW exec permission - * is supposed per page (currently 64-bit only). If not, then, we always - * flush the cache for valid PTEs in set_pte. Embedded CPU without HW exec - * support falls into the same category. - */ - -static pte_t set_pte_filter(pte_t pte, unsigned long addr) -{ - pte = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS); - if (pte_looks_normal(pte) && !(cpu_has_feature(CPU_FTR_COHERENT_ICACHE) || - cpu_has_feature(CPU_FTR_NOEXECUTE))) { - struct page *pg = maybe_pte_to_page(pte); - if (!pg) - return pte; - if (!test_bit(PG_arch_1, &pg->flags)) { -#ifdef CONFIG_8xx - /* On 8xx, cache control instructions (particularly - * "dcbst" from flush_dcache_icache) fault as write - * operation if there is an unpopulated TLB entry - * for the address in question. To workaround that, - * we invalidate the TLB here, thus avoiding dcbst - * misbehaviour. - */ - /* 8xx doesn't care about PID, size or ind args */ - _tlbil_va(addr, 0, 0, 0); -#endif /* CONFIG_8xx */ - flush_dcache_icache_page(pg); - set_bit(PG_arch_1, &pg->flags); - } - } - return pte; -} - -static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma, - int dirty) -{ - return pte; -} - -#else /* defined(CONFIG_PPC_STD_MMU) || _PAGE_EXEC == 0 */ - -/* Embedded type MMU with HW exec support. This is a bit more complicated - * as we don't have two bits to spare for _PAGE_EXEC and _PAGE_HWEXEC so - * instead we "filter out" the exec permission for non clean pages. - */ -static pte_t set_pte_filter(pte_t pte, unsigned long addr) -{ - struct page *pg; - - /* No exec permission in the first place, move on */ - if (!(pte_val(pte) & _PAGE_EXEC) || !pte_looks_normal(pte)) - return pte; - - /* If you set _PAGE_EXEC on weird pages you're on your own */ - pg = maybe_pte_to_page(pte); - if (unlikely(!pg)) - return pte; - - /* If the page clean, we move on */ - if (test_bit(PG_arch_1, &pg->flags)) - return pte; - - /* If it's an exec fault, we flush the cache and make it clean */ - if (is_exec_fault()) { - flush_dcache_icache_page(pg); - set_bit(PG_arch_1, &pg->flags); - return pte; - } - - /* Else, we filter out _PAGE_EXEC */ - return __pte(pte_val(pte) & ~_PAGE_EXEC); -} - -static pte_t set_access_flags_filter(pte_t pte, struct vm_area_struct *vma, - int dirty) -{ - struct page *pg; - - /* So here, we only care about exec faults, as we use them - * to recover lost _PAGE_EXEC and perform I$/D$ coherency - * if necessary. Also if _PAGE_EXEC is already set, same deal, - * we just bail out - */ - if (dirty || (pte_val(pte) & _PAGE_EXEC) || !is_exec_fault()) - return pte; - -#ifdef CONFIG_DEBUG_VM - /* So this is an exec fault, _PAGE_EXEC is not set. If it was - * an error we would have bailed out earlier in do_page_fault() - * but let's make sure of it - */ - if (WARN_ON(!(vma->vm_flags & VM_EXEC))) - return pte; -#endif /* CONFIG_DEBUG_VM */ - - /* If you set _PAGE_EXEC on weird pages you're on your own */ - pg = maybe_pte_to_page(pte); - if (unlikely(!pg)) - goto bail; - - /* If the page is already clean, we move on */ - if (test_bit(PG_arch_1, &pg->flags)) - goto bail; - - /* Clean the page and set PG_arch_1 */ - flush_dcache_icache_page(pg); - set_bit(PG_arch_1, &pg->flags); - - bail: - return __pte(pte_val(pte) | _PAGE_EXEC); -} - -#endif /* !(defined(CONFIG_PPC_STD_MMU) || _PAGE_EXEC == 0) */ - -/* - * set_pte stores a linux PTE into the linux page table. - */ -void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, - pte_t pte) -{ -#ifdef CONFIG_DEBUG_VM - WARN_ON(pte_present(*ptep)); -#endif - /* Note: mm->context.id might not yet have been assigned as - * this context might not have been activated yet when this - * is called. - */ - pte = set_pte_filter(pte, addr); - - /* Perform the setting of the PTE */ - __set_pte_at(mm, addr, ptep, pte, 0); -} - -/* - * This is called when relaxing access to a PTE. It's also called in the page - * fault path when we don't hit any of the major fault cases, ie, a minor - * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have - * handled those two for us, we additionally deal with missing execute - * permission here on some processors - */ -int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, - pte_t *ptep, pte_t entry, int dirty) -{ - int changed; - entry = set_access_flags_filter(entry, vma, dirty); - changed = !pte_same(*(ptep), entry); - if (changed) { - if (!is_vm_hugetlb_page(vma)) - assert_pte_locked(vma->vm_mm, address); - __ptep_set_access_flags(ptep, entry); - flush_tlb_page_nohash(vma, address); - } - return changed; -} - -#ifdef CONFIG_DEBUG_VM -void assert_pte_locked(struct mm_struct *mm, unsigned long addr) -{ - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - - if (mm == &init_mm) - return; - pgd = mm->pgd + pgd_index(addr); - BUG_ON(pgd_none(*pgd)); - pud = pud_offset(pgd, addr); - BUG_ON(pud_none(*pud)); - pmd = pmd_offset(pud, addr); - BUG_ON(!pmd_present(*pmd)); - assert_spin_locked(pte_lockptr(mm, pmd)); -} -#endif /* CONFIG_DEBUG_VM */ - |