473 lines
11 KiB
C
473 lines
11 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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* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
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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/config.h>
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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 <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/io.h>
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#include "mmu_decl.h"
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unsigned long ioremap_base;
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unsigned long ioremap_bot;
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EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
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int io_bat_index;
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#if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
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#define HAVE_BATS 1
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#endif
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#if defined(CONFIG_FSL_BOOKE)
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#define HAVE_TLBCAM 1
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#endif
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extern char etext[], _stext[];
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#ifdef CONFIG_SMP
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extern void hash_page_sync(void);
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#endif
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#ifdef HAVE_BATS
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extern unsigned long v_mapped_by_bats(unsigned long va);
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extern unsigned long p_mapped_by_bats(unsigned long pa);
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void setbat(int index, unsigned long virt, unsigned long phys,
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unsigned int size, int flags);
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#else /* !HAVE_BATS */
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#define v_mapped_by_bats(x) (0UL)
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#define p_mapped_by_bats(x) (0UL)
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#endif /* HAVE_BATS */
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#ifdef HAVE_TLBCAM
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extern unsigned int tlbcam_index;
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extern unsigned long v_mapped_by_tlbcam(unsigned long va);
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extern unsigned long p_mapped_by_tlbcam(unsigned long pa);
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#else /* !HAVE_TLBCAM */
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#define v_mapped_by_tlbcam(x) (0UL)
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#define p_mapped_by_tlbcam(x) (0UL)
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#endif /* HAVE_TLBCAM */
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#ifdef CONFIG_PTE_64BIT
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/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
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#define PGDIR_ORDER 1
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#else
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#define PGDIR_ORDER 0
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#endif
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pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *ret;
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ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
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return ret;
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}
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void pgd_free(pgd_t *pgd)
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{
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free_pages((unsigned long)pgd, PGDIR_ORDER);
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}
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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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extern int mem_init_done;
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extern void *early_get_page(void);
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if (mem_init_done) {
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pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
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} else {
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pte = (pte_t *)early_get_page();
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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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struct page *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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#ifdef CONFIG_HIGHPTE
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gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
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#else
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gfp_t flags = GFP_KERNEL | __GFP_REPEAT;
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#endif
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ptepage = alloc_pages(flags, 0);
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if (ptepage)
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clear_highpage(ptepage);
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return ptepage;
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}
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void pte_free_kernel(pte_t *pte)
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{
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#ifdef CONFIG_SMP
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hash_page_sync();
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#endif
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free_page((unsigned long)pte);
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}
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void pte_free(struct page *ptepage)
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{
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#ifdef CONFIG_SMP
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hash_page_sync();
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#endif
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__free_page(ptepage);
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}
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#ifndef CONFIG_PHYS_64BIT
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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(addr, size, _PAGE_NO_CACHE);
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}
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#else /* CONFIG_PHYS_64BIT */
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void __iomem *
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ioremap64(unsigned long long addr, unsigned long size)
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{
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return __ioremap(addr, size, _PAGE_NO_CACHE);
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}
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EXPORT_SYMBOL(ioremap64);
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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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phys_addr_t addr64 = fixup_bigphys_addr(addr, size);
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return ioremap64(addr64, size);
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}
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#endif /* CONFIG_PHYS_64BIT */
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EXPORT_SYMBOL(ioremap);
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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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unsigned long v, i;
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phys_addr_t p;
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int err;
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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_base
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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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/*
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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 (mem_init_done && (p < virt_to_phys(high_memory))) {
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printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p,
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__builtin_return_address(0));
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return NULL;
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}
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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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* BAT mapping. If the whole area is mapped then we're done,
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* otherwise remap it since we want to keep the virt addrs for
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* each request contiguous.
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*
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* We make the assumption here that if the bottom and top
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* of the range we want are mapped then it's mapped to the
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* same virt address (and this is contiguous).
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* -- Cort
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*/
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if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
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goto out;
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if ((v = p_mapped_by_tlbcam(p)))
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goto out;
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if (mem_init_done) {
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struct vm_struct *area;
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area = get_vm_area(size, VM_IOREMAP);
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if (area == 0)
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return NULL;
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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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if ((flags & _PAGE_PRESENT) == 0)
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flags |= _PAGE_KERNEL;
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if (flags & _PAGE_NO_CACHE)
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flags |= _PAGE_GUARDED;
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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_page(v+i, p+i, flags);
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if (err) {
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if (mem_init_done)
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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_mapped_by_bats((unsigned long)addr)) 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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void __iomem *ioport_map(unsigned long port, unsigned int len)
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{
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return (void __iomem *) (port + _IO_BASE);
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}
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void ioport_unmap(void __iomem *addr)
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{
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/* Nothing to do */
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}
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EXPORT_SYMBOL(ioport_map);
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EXPORT_SYMBOL(ioport_unmap);
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int
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map_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(pgd_offset_k(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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set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
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if (mem_init_done)
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flush_HPTE(0, va, pmd_val(*pd));
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}
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return err;
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}
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/*
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* Map in all of physical memory starting at KERNELBASE.
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*/
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void __init mapin_ram(void)
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{
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unsigned long v, p, s, f;
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s = mmu_mapin_ram();
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v = KERNELBASE + s;
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p = PPC_MEMSTART + s;
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for (; s < total_lowmem; s += PAGE_SIZE) {
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if ((char *) v >= _stext && (char *) v < etext)
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f = _PAGE_RAM_TEXT;
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else
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f = _PAGE_RAM;
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map_page(v, p, f);
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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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/* is x a power of 2? */
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#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
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/* is x a power of 4? */
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#define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1))
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/*
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* Set up a mapping for a block of I/O.
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* virt, phys, size must all be page-aligned.
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* This should only be called before ioremap is called.
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*/
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void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
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unsigned int size, int flags)
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{
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int i;
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if (virt > KERNELBASE && virt < ioremap_bot)
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ioremap_bot = ioremap_base = virt;
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#ifdef HAVE_BATS
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/*
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* Use a BAT for this if possible...
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*/
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if (io_bat_index < 2 && is_power_of_2(size)
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&& (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
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setbat(io_bat_index, virt, phys, size, flags);
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++io_bat_index;
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return;
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}
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#endif /* HAVE_BATS */
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#ifdef HAVE_TLBCAM
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/*
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* Use a CAM for this if possible...
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*/
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if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size)
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&& (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
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settlbcam(tlbcam_index, virt, phys, size, flags, 0);
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++tlbcam_index;
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return;
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}
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#endif /* HAVE_TLBCAM */
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/* No BATs available, put it in the page tables. */
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for (i = 0; i < size; i += PAGE_SIZE)
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map_page(virt + i, phys + i, flags);
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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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int
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get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
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{
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pgd_t *pgd;
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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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pmd = pmd_offset(pgd, 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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/* XXX caller needs to do pte_unmap, yuck */
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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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/* Find physical address for this virtual address. Normally used by
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* I/O functions, but anyone can call it.
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*/
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unsigned long iopa(unsigned long addr)
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{
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unsigned long pa;
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/* I don't know why this won't work on PMacs or CHRP. It
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* appears there is some bug, or there is some implicit
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* mapping done not properly represented by BATs or in page
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* tables.......I am actively working on resolving this, but
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* can't hold up other stuff. -- Dan
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*/
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pte_t *pte;
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struct mm_struct *mm;
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/* Check the BATs */
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pa = v_mapped_by_bats(addr);
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if (pa)
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return pa;
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/* Allow mapping of user addresses (within the thread)
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* for DMA if necessary.
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*/
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if (addr < TASK_SIZE)
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mm = current->mm;
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else
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mm = &init_mm;
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pa = 0;
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if (get_pteptr(mm, addr, &pte)) {
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pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
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pte_unmap(pte);
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}
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return(pa);
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}
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/* This is will find the virtual address for a physical one....
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* Swiped from APUS, could be dangerous :-).
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* This is only a placeholder until I really find a way to make this
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* work. -- Dan
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*/
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unsigned long
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mm_ptov (unsigned long paddr)
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{
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unsigned long ret;
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#if 0
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if (paddr < 16*1024*1024)
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ret = ZTWO_VADDR(paddr);
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else {
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int i;
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for (i = 0; i < kmap_chunk_count;){
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unsigned long phys = kmap_chunks[i++];
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unsigned long size = kmap_chunks[i++];
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unsigned long virt = kmap_chunks[i++];
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if (paddr >= phys
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&& paddr < (phys + size)){
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ret = virt + paddr - phys;
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goto exit;
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}
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}
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ret = (unsigned long) __va(paddr);
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}
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exit:
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#ifdef DEBUGPV
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printk ("PTOV(%lx)=%lx\n", paddr, ret);
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#endif
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#else
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ret = (unsigned long)paddr + KERNELBASE;
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#endif
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return ret;
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}
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