![Robin Holt](/assets/img/avatar_default.png)
Prepare for the moving the parsing of reboot= to the generic kernel code by making reboot_mode into a more generic form. Signed-off-by: Robin Holt <holt@sgi.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
513 lines
13 KiB
C
513 lines
13 KiB
C
/*
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* linux/arch/unicore32/mm/mmu.c
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2010 GUAN Xue-tao
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/mman.h>
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#include <linux/nodemask.h>
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#include <linux/memblock.h>
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#include <linux/fs.h>
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#include <linux/bootmem.h>
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#include <linux/io.h>
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#include <asm/cputype.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/sizes.h>
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#include <asm/tlb.h>
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#include <asm/memblock.h>
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#include <mach/map.h>
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#include "mm.h"
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/*
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* empty_zero_page is a special page that is used for
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* zero-initialized data and COW.
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*/
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struct page *empty_zero_page;
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EXPORT_SYMBOL(empty_zero_page);
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/*
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* The pmd table for the upper-most set of pages.
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*/
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pmd_t *top_pmd;
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pgprot_t pgprot_user;
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EXPORT_SYMBOL(pgprot_user);
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pgprot_t pgprot_kernel;
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EXPORT_SYMBOL(pgprot_kernel);
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static int __init noalign_setup(char *__unused)
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{
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cr_alignment &= ~CR_A;
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cr_no_alignment &= ~CR_A;
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set_cr(cr_alignment);
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return 1;
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}
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__setup("noalign", noalign_setup);
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void adjust_cr(unsigned long mask, unsigned long set)
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{
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unsigned long flags;
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mask &= ~CR_A;
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set &= mask;
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local_irq_save(flags);
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cr_no_alignment = (cr_no_alignment & ~mask) | set;
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cr_alignment = (cr_alignment & ~mask) | set;
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set_cr((get_cr() & ~mask) | set);
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local_irq_restore(flags);
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}
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struct map_desc {
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unsigned long virtual;
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unsigned long pfn;
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unsigned long length;
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unsigned int type;
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};
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#define PROT_PTE_DEVICE (PTE_PRESENT | PTE_YOUNG | \
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PTE_DIRTY | PTE_READ | PTE_WRITE)
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#define PROT_SECT_DEVICE (PMD_TYPE_SECT | PMD_PRESENT | \
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PMD_SECT_READ | PMD_SECT_WRITE)
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static struct mem_type mem_types[] = {
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[MT_DEVICE] = { /* Strongly ordered */
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.prot_pte = PROT_PTE_DEVICE,
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.prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT,
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.prot_sect = PROT_SECT_DEVICE,
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},
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/*
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* MT_KUSER: pte for vecpage -- cacheable,
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* and sect for unigfx mmap -- noncacheable
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*/
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[MT_KUSER] = {
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.prot_pte = PTE_PRESENT | PTE_YOUNG | PTE_DIRTY |
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PTE_CACHEABLE | PTE_READ | PTE_EXEC,
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.prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT,
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.prot_sect = PROT_SECT_DEVICE,
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},
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[MT_HIGH_VECTORS] = {
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.prot_pte = PTE_PRESENT | PTE_YOUNG | PTE_DIRTY |
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PTE_CACHEABLE | PTE_READ | PTE_WRITE |
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PTE_EXEC,
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.prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT,
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},
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[MT_MEMORY] = {
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.prot_pte = PTE_PRESENT | PTE_YOUNG | PTE_DIRTY |
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PTE_WRITE | PTE_EXEC,
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.prot_l1 = PMD_TYPE_TABLE | PMD_PRESENT,
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.prot_sect = PMD_TYPE_SECT | PMD_PRESENT | PMD_SECT_CACHEABLE |
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PMD_SECT_READ | PMD_SECT_WRITE | PMD_SECT_EXEC,
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},
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[MT_ROM] = {
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.prot_sect = PMD_TYPE_SECT | PMD_PRESENT | PMD_SECT_CACHEABLE |
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PMD_SECT_READ,
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},
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};
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const struct mem_type *get_mem_type(unsigned int type)
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{
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return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
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}
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EXPORT_SYMBOL(get_mem_type);
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/*
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* Adjust the PMD section entries according to the CPU in use.
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*/
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static void __init build_mem_type_table(void)
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{
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pgprot_user = __pgprot(PTE_PRESENT | PTE_YOUNG | PTE_CACHEABLE);
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pgprot_kernel = __pgprot(PTE_PRESENT | PTE_YOUNG |
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PTE_DIRTY | PTE_READ | PTE_WRITE |
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PTE_EXEC | PTE_CACHEABLE);
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}
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#define vectors_base() (vectors_high() ? 0xffff0000 : 0)
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static void __init *early_alloc(unsigned long sz)
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{
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void *ptr = __va(memblock_alloc(sz, sz));
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memset(ptr, 0, sz);
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return ptr;
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}
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static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr,
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unsigned long prot)
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{
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if (pmd_none(*pmd)) {
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pte_t *pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t));
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__pmd_populate(pmd, __pa(pte) | prot);
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}
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BUG_ON(pmd_bad(*pmd));
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return pte_offset_kernel(pmd, addr);
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}
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static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
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unsigned long end, unsigned long pfn,
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const struct mem_type *type)
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{
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pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1);
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do {
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set_pte(pte, pfn_pte(pfn, __pgprot(type->prot_pte)));
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pfn++;
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} while (pte++, addr += PAGE_SIZE, addr != end);
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}
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static void __init alloc_init_section(pgd_t *pgd, unsigned long addr,
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unsigned long end, unsigned long phys,
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const struct mem_type *type)
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{
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pmd_t *pmd = pmd_offset((pud_t *)pgd, addr);
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/*
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* Try a section mapping - end, addr and phys must all be aligned
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* to a section boundary.
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*/
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if (((addr | end | phys) & ~SECTION_MASK) == 0) {
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pmd_t *p = pmd;
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do {
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set_pmd(pmd, __pmd(phys | type->prot_sect));
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phys += SECTION_SIZE;
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} while (pmd++, addr += SECTION_SIZE, addr != end);
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flush_pmd_entry(p);
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} else {
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/*
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* No need to loop; pte's aren't interested in the
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* individual L1 entries.
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*/
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alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type);
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}
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}
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/*
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* Create the page directory entries and any necessary
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* page tables for the mapping specified by `md'. We
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* are able to cope here with varying sizes and address
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* offsets, and we take full advantage of sections.
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*/
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static void __init create_mapping(struct map_desc *md)
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{
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unsigned long phys, addr, length, end;
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const struct mem_type *type;
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pgd_t *pgd;
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if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
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printk(KERN_WARNING "BUG: not creating mapping for "
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"0x%08llx at 0x%08lx in user region\n",
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__pfn_to_phys((u64)md->pfn), md->virtual);
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return;
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}
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if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
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md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
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printk(KERN_WARNING "BUG: mapping for 0x%08llx at 0x%08lx "
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"overlaps vmalloc space\n",
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__pfn_to_phys((u64)md->pfn), md->virtual);
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}
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type = &mem_types[md->type];
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addr = md->virtual & PAGE_MASK;
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phys = (unsigned long)__pfn_to_phys(md->pfn);
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length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
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if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) {
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printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not "
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"be mapped using pages, ignoring.\n",
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__pfn_to_phys(md->pfn), addr);
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return;
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}
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pgd = pgd_offset_k(addr);
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end = addr + length;
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do {
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unsigned long next = pgd_addr_end(addr, end);
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alloc_init_section(pgd, addr, next, phys, type);
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phys += next - addr;
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addr = next;
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} while (pgd++, addr != end);
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}
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static void * __initdata vmalloc_min = (void *)(VMALLOC_END - SZ_128M);
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/*
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* vmalloc=size forces the vmalloc area to be exactly 'size'
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* bytes. This can be used to increase (or decrease) the vmalloc
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* area - the default is 128m.
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*/
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static int __init early_vmalloc(char *arg)
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{
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unsigned long vmalloc_reserve = memparse(arg, NULL);
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if (vmalloc_reserve < SZ_16M) {
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vmalloc_reserve = SZ_16M;
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printk(KERN_WARNING
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"vmalloc area too small, limiting to %luMB\n",
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vmalloc_reserve >> 20);
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}
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if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
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vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
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printk(KERN_WARNING
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"vmalloc area is too big, limiting to %luMB\n",
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vmalloc_reserve >> 20);
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}
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vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve);
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return 0;
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}
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early_param("vmalloc", early_vmalloc);
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static phys_addr_t lowmem_limit __initdata = SZ_1G;
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static void __init sanity_check_meminfo(void)
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{
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int i, j;
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lowmem_limit = __pa(vmalloc_min - 1) + 1;
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memblock_set_current_limit(lowmem_limit);
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for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
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struct membank *bank = &meminfo.bank[j];
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*bank = meminfo.bank[i];
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j++;
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}
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meminfo.nr_banks = j;
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}
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static inline void prepare_page_table(void)
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{
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unsigned long addr;
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phys_addr_t end;
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/*
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* Clear out all the mappings below the kernel image.
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*/
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for (addr = 0; addr < MODULES_VADDR; addr += PGDIR_SIZE)
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pmd_clear(pmd_off_k(addr));
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for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE)
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pmd_clear(pmd_off_k(addr));
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/*
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* Find the end of the first block of lowmem.
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*/
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end = memblock.memory.regions[0].base + memblock.memory.regions[0].size;
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if (end >= lowmem_limit)
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end = lowmem_limit;
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/*
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* Clear out all the kernel space mappings, except for the first
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* memory bank, up to the end of the vmalloc region.
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*/
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for (addr = __phys_to_virt(end);
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addr < VMALLOC_END; addr += PGDIR_SIZE)
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pmd_clear(pmd_off_k(addr));
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}
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/*
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* Reserve the special regions of memory
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*/
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void __init uc32_mm_memblock_reserve(void)
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{
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/*
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* Reserve the page tables. These are already in use,
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* and can only be in node 0.
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*/
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memblock_reserve(__pa(swapper_pg_dir), PTRS_PER_PGD * sizeof(pgd_t));
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}
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/*
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* Set up device the mappings. Since we clear out the page tables for all
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* mappings above VMALLOC_END, we will remove any debug device mappings.
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* This means you have to be careful how you debug this function, or any
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* called function. This means you can't use any function or debugging
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* method which may touch any device, otherwise the kernel _will_ crash.
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*/
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static void __init devicemaps_init(void)
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{
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struct map_desc map;
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unsigned long addr;
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void *vectors;
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/*
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* Allocate the vector page early.
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*/
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vectors = early_alloc(PAGE_SIZE);
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for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)
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pmd_clear(pmd_off_k(addr));
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/*
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* Create a mapping for the machine vectors at the high-vectors
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* location (0xffff0000). If we aren't using high-vectors, also
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* create a mapping at the low-vectors virtual address.
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*/
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map.pfn = __phys_to_pfn(virt_to_phys(vectors));
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map.virtual = VECTORS_BASE;
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map.length = PAGE_SIZE;
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map.type = MT_HIGH_VECTORS;
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create_mapping(&map);
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/*
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* Create a mapping for the kuser page at the special
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* location (0xbfff0000) to the same vectors location.
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*/
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map.pfn = __phys_to_pfn(virt_to_phys(vectors));
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map.virtual = KUSER_VECPAGE_BASE;
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map.length = PAGE_SIZE;
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map.type = MT_KUSER;
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create_mapping(&map);
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/*
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* Finally flush the caches and tlb to ensure that we're in a
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* consistent state wrt the writebuffer. This also ensures that
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* any write-allocated cache lines in the vector page are written
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* back. After this point, we can start to touch devices again.
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*/
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local_flush_tlb_all();
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flush_cache_all();
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}
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static void __init map_lowmem(void)
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{
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struct memblock_region *reg;
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/* Map all the lowmem memory banks. */
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for_each_memblock(memory, reg) {
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phys_addr_t start = reg->base;
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phys_addr_t end = start + reg->size;
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struct map_desc map;
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if (end > lowmem_limit)
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end = lowmem_limit;
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if (start >= end)
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break;
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map.pfn = __phys_to_pfn(start);
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map.virtual = __phys_to_virt(start);
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map.length = end - start;
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map.type = MT_MEMORY;
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create_mapping(&map);
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}
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}
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/*
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* paging_init() sets up the page tables, initialises the zone memory
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* maps, and sets up the zero page, bad page and bad page tables.
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*/
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void __init paging_init(void)
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{
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void *zero_page;
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build_mem_type_table();
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sanity_check_meminfo();
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prepare_page_table();
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map_lowmem();
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devicemaps_init();
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top_pmd = pmd_off_k(0xffff0000);
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/* allocate the zero page. */
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zero_page = early_alloc(PAGE_SIZE);
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bootmem_init();
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empty_zero_page = virt_to_page(zero_page);
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__flush_dcache_page(NULL, empty_zero_page);
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}
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/*
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* In order to soft-boot, we need to insert a 1:1 mapping in place of
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* the user-mode pages. This will then ensure that we have predictable
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* results when turning the mmu off
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*/
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void setup_mm_for_reboot(void)
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{
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unsigned long base_pmdval;
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pgd_t *pgd;
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int i;
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/*
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* We need to access to user-mode page tables here. For kernel threads
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* we don't have any user-mode mappings so we use the context that we
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* "borrowed".
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*/
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pgd = current->active_mm->pgd;
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base_pmdval = PMD_SECT_WRITE | PMD_SECT_READ | PMD_TYPE_SECT;
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for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {
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unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval;
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pmd_t *pmd;
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pmd = pmd_off(pgd, i << PGDIR_SHIFT);
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set_pmd(pmd, __pmd(pmdval));
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flush_pmd_entry(pmd);
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}
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local_flush_tlb_all();
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}
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/*
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* Take care of architecture specific things when placing a new PTE into
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* a page table, or changing an existing PTE. Basically, there are two
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* things that we need to take care of:
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*
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* 1. If PG_dcache_clean is not set for the page, we need to ensure
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* that any cache entries for the kernels virtual memory
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* range are written back to the page.
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* 2. If we have multiple shared mappings of the same space in
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* an object, we need to deal with the cache aliasing issues.
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*
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* Note that the pte lock will be held.
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*/
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void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
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pte_t *ptep)
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{
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unsigned long pfn = pte_pfn(*ptep);
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struct address_space *mapping;
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struct page *page;
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if (!pfn_valid(pfn))
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return;
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/*
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* The zero page is never written to, so never has any dirty
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* cache lines, and therefore never needs to be flushed.
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*/
|
|
page = pfn_to_page(pfn);
|
|
if (page == ZERO_PAGE(0))
|
|
return;
|
|
|
|
mapping = page_mapping(page);
|
|
if (!test_and_set_bit(PG_dcache_clean, &page->flags))
|
|
__flush_dcache_page(mapping, page);
|
|
if (mapping)
|
|
if (vma->vm_flags & VM_EXEC)
|
|
__flush_icache_all();
|
|
}
|