![Christophe Leroy](/assets/img/avatar_default.png)
commit ac29c64089
("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64
This patch generalises _PAGE_PRIVILEGED for all CPUs, allowing
to have either _PAGE_PRIVILEGED or _PAGE_USER or both.
PPC_8xx has a _PAGE_SHARED flag which is set for and only for
all non user pages. Lets rename it _PAGE_PRIVILEGED to remove
confusion as it has nothing to do with Linux shared pages.
On BookE, there's a _PAGE_BAP_SR which has to be set for kernel
pages: defining _PAGE_PRIVILEGED as _PAGE_BAP_SR will make
this generic
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
404 lines
9.6 KiB
C
404 lines
9.6 KiB
C
/*
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* This file contains the routines setting up the linux page tables.
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* -- paulus
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*
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* Derived from arch/ppc/mm/init.c:
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/init.h>
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#include <linux/highmem.h>
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#include <linux/memblock.h>
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#include <linux/slab.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/fixmap.h>
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#include <asm/io.h>
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#include <asm/setup.h>
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#include <asm/sections.h>
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#include "mmu_decl.h"
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unsigned long ioremap_bot;
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EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
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extern char etext[], _stext[], _sinittext[], _einittext[];
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__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
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{
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pte_t *pte;
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if (slab_is_available()) {
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pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
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} else {
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pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
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if (pte)
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clear_page(pte);
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}
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return pte;
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}
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pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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struct page *ptepage;
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gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT;
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ptepage = alloc_pages(flags, 0);
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if (!ptepage)
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return NULL;
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if (!pgtable_page_ctor(ptepage)) {
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__free_page(ptepage);
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return NULL;
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}
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return ptepage;
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}
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void __iomem *
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ioremap(phys_addr_t addr, unsigned long size)
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{
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return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap);
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void __iomem *
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ioremap_wc(phys_addr_t addr, unsigned long size)
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{
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return __ioremap_caller(addr, size, _PAGE_NO_CACHE,
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__builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap_wc);
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void __iomem *
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ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
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{
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/* writeable implies dirty for kernel addresses */
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if ((flags & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO)
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flags |= _PAGE_DIRTY | _PAGE_HWWRITE;
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/* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
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flags &= ~(_PAGE_USER | _PAGE_EXEC);
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flags |= _PAGE_PRIVILEGED;
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return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
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}
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EXPORT_SYMBOL(ioremap_prot);
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void __iomem *
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__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
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{
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return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
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}
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void __iomem *
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__ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
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void *caller)
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{
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unsigned long v, i;
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phys_addr_t p;
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int err;
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/* Make sure we have the base flags */
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if ((flags & _PAGE_PRESENT) == 0)
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flags |= pgprot_val(PAGE_KERNEL);
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/* Non-cacheable page cannot be coherent */
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if (flags & _PAGE_NO_CACHE)
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flags &= ~_PAGE_COHERENT;
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/*
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* Choose an address to map it to.
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* Once the vmalloc system is running, we use it.
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* Before then, we use space going down from IOREMAP_TOP
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* (ioremap_bot records where we're up to).
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*/
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p = addr & PAGE_MASK;
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size = PAGE_ALIGN(addr + size) - p;
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/*
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* If the address lies within the first 16 MB, assume it's in ISA
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* memory space
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*/
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if (p < 16*1024*1024)
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p += _ISA_MEM_BASE;
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#ifndef CONFIG_CRASH_DUMP
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/*
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* Don't allow anybody to remap normal RAM that we're using.
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* mem_init() sets high_memory so only do the check after that.
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*/
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if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
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!(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
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printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
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(unsigned long long)p, __builtin_return_address(0));
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return NULL;
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}
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#endif
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if (size == 0)
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return NULL;
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/*
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* Is it already mapped? Perhaps overlapped by a previous
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* mapping.
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*/
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v = p_block_mapped(p);
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if (v)
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goto out;
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if (slab_is_available()) {
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struct vm_struct *area;
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area = get_vm_area_caller(size, VM_IOREMAP, caller);
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if (area == 0)
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return NULL;
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area->phys_addr = p;
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v = (unsigned long) area->addr;
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} else {
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v = (ioremap_bot -= size);
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}
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/*
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* Should check if it is a candidate for a BAT mapping
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*/
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err = 0;
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for (i = 0; i < size && err == 0; i += PAGE_SIZE)
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err = map_kernel_page(v+i, p+i, flags);
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if (err) {
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if (slab_is_available())
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vunmap((void *)v);
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return NULL;
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}
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out:
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return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
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}
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EXPORT_SYMBOL(__ioremap);
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void iounmap(volatile void __iomem *addr)
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{
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/*
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* If mapped by BATs then there is nothing to do.
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* Calling vfree() generates a benign warning.
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*/
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if (v_block_mapped((unsigned long)addr))
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return;
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if (addr > high_memory && (unsigned long) addr < ioremap_bot)
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vunmap((void *) (PAGE_MASK & (unsigned long)addr));
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}
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EXPORT_SYMBOL(iounmap);
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int map_kernel_page(unsigned long va, phys_addr_t pa, int flags)
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{
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pmd_t *pd;
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pte_t *pg;
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int err = -ENOMEM;
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/* Use upper 10 bits of VA to index the first level map */
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pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
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/* Use middle 10 bits of VA to index the second-level map */
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pg = pte_alloc_kernel(pd, va);
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if (pg != 0) {
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err = 0;
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/* The PTE should never be already set nor present in the
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* hash table
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*/
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BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) &&
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flags);
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set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
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__pgprot(flags)));
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}
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smp_wmb();
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return err;
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}
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/*
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* Map in a chunk of physical memory starting at start.
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*/
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static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
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{
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unsigned long v, s, f;
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phys_addr_t p;
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int ktext;
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s = offset;
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v = PAGE_OFFSET + s;
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p = memstart_addr + s;
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for (; s < top; s += PAGE_SIZE) {
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ktext = ((char *)v >= _stext && (char *)v < etext) ||
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((char *)v >= _sinittext && (char *)v < _einittext);
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f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL);
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map_kernel_page(v, p, f);
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#ifdef CONFIG_PPC_STD_MMU_32
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if (ktext)
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hash_preload(&init_mm, v, 0, 0x300);
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#endif
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v += PAGE_SIZE;
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p += PAGE_SIZE;
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}
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}
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void __init mapin_ram(void)
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{
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unsigned long s, top;
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#ifndef CONFIG_WII
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top = total_lowmem;
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s = mmu_mapin_ram(top);
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__mapin_ram_chunk(s, top);
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#else
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if (!wii_hole_size) {
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s = mmu_mapin_ram(total_lowmem);
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__mapin_ram_chunk(s, total_lowmem);
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} else {
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top = wii_hole_start;
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s = mmu_mapin_ram(top);
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__mapin_ram_chunk(s, top);
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top = memblock_end_of_DRAM();
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s = wii_mmu_mapin_mem2(top);
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__mapin_ram_chunk(s, top);
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}
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#endif
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}
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/* Scan the real Linux page tables and return a PTE pointer for
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* a virtual address in a context.
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* Returns true (1) if PTE was found, zero otherwise. The pointer to
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* the PTE pointer is unmodified if PTE is not found.
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*/
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static int
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get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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pte_t *pte;
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int retval = 0;
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pgd = pgd_offset(mm, addr & PAGE_MASK);
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if (pgd) {
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pud = pud_offset(pgd, addr & PAGE_MASK);
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if (pud && pud_present(*pud)) {
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pmd = pmd_offset(pud, addr & PAGE_MASK);
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if (pmd_present(*pmd)) {
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pte = pte_offset_map(pmd, addr & PAGE_MASK);
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if (pte) {
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retval = 1;
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*ptep = pte;
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if (pmdp)
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*pmdp = pmd;
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/* XXX caller needs to do pte_unmap, yuck */
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}
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}
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}
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}
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return(retval);
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}
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static int __change_page_attr_noflush(struct page *page, pgprot_t prot)
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{
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pte_t *kpte;
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pmd_t *kpmd;
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unsigned long address;
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BUG_ON(PageHighMem(page));
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address = (unsigned long)page_address(page);
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if (v_block_mapped(address))
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return 0;
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if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
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return -EINVAL;
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__set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
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pte_unmap(kpte);
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return 0;
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}
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/*
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* Change the page attributes of an page in the linear mapping.
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*
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* THIS DOES NOTHING WITH BAT MAPPINGS, DEBUG USE ONLY
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*/
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static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
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{
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int i, err = 0;
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unsigned long flags;
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struct page *start = page;
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local_irq_save(flags);
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for (i = 0; i < numpages; i++, page++) {
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err = __change_page_attr_noflush(page, prot);
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if (err)
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break;
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}
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wmb();
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local_irq_restore(flags);
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flush_tlb_kernel_range((unsigned long)page_address(start),
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(unsigned long)page_address(page));
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return err;
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}
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void mark_initmem_nx(void)
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{
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struct page *page = virt_to_page(_sinittext);
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unsigned long numpages = PFN_UP((unsigned long)_einittext) -
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PFN_DOWN((unsigned long)_sinittext);
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change_page_attr(page, numpages, PAGE_KERNEL);
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}
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#ifdef CONFIG_STRICT_KERNEL_RWX
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void mark_rodata_ro(void)
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{
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struct page *page;
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unsigned long numpages;
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page = virt_to_page(_stext);
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numpages = PFN_UP((unsigned long)_etext) -
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PFN_DOWN((unsigned long)_stext);
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change_page_attr(page, numpages, PAGE_KERNEL_ROX);
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/*
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* mark .rodata as read only. Use __init_begin rather than __end_rodata
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* to cover NOTES and EXCEPTION_TABLE.
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*/
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page = virt_to_page(__start_rodata);
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numpages = PFN_UP((unsigned long)__init_begin) -
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PFN_DOWN((unsigned long)__start_rodata);
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change_page_attr(page, numpages, PAGE_KERNEL_RO);
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}
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#endif
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#ifdef CONFIG_DEBUG_PAGEALLOC
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void __kernel_map_pages(struct page *page, int numpages, int enable)
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{
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if (PageHighMem(page))
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return;
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change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
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}
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#endif /* CONFIG_DEBUG_PAGEALLOC */
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