/*
* This file contains the routines setting up the linux page tables.
* -- paulus
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/io.h>
#include "mmu_decl.h"
unsigned long ioremap_base;
unsigned long ioremap_bot;
int io_bat_index;
#if defined(CONFIG_6xx)
#define HAVE_BATS 1
#endif
extern char etext[], _stext[];
#ifdef CONFIG_SMP
extern void hash_page_sync(void);
#endif
#ifdef HAVE_BATS
extern unsigned long v_mapped_by_bats(unsigned long va);
extern unsigned long p_mapped_by_bats(unsigned long pa);
void setbat(int index, unsigned long virt, unsigned long phys,
unsigned int size, int flags);
#else /* !HAVE_BATS */
#define v_mapped_by_bats(x) (0UL)
#define p_mapped_by_bats(x) (0UL)
#endif /* HAVE_BATS */
#ifdef CONFIG_PTE_64BIT
/* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */
#define PGDIR_ORDER 1
#else
#define PGDIR_ORDER 0
#endif
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *ret;
ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER);
return ret;
}
void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
free_pages((unsigned long)pgd, PGDIR_ORDER);
}
__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
{
pte_t *pte;
extern int mem_init_done;
extern void *early_get_page(void);
if (mem_init_done) {
pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
} else {
pte = (pte_t *)early_get_page();
if (pte)
clear_page(pte);
}
return pte;
}
pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
{
struct page *ptepage;
#ifdef CONFIG_HIGHPTE
gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
#else
gfp_t flags = GFP_KERNEL | __GFP_REPEAT;
#endif
ptepage = alloc_pages(flags, 0);
if (ptepage) {
clear_highpage(ptepage);
pgtable_page_ctor(ptepage);
}
return ptepage;
}
void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
{
#ifdef CONFIG_SMP
hash_page_sync();
#endif
free_page((unsigned long)pte);
}
void pte_free(struct mm_struct *mm, pgtable_t ptepage)
{
#ifdef CONFIG_SMP
hash_page_sync();
#endif
pgtable_page_dtor(ptepage);
__free_page(ptepage);
}
#ifndef CONFIG_PHYS_64BIT
void __iomem *
ioremap(phys_addr_t addr, unsigned long size)
{
return __ioremap(addr, size, _PAGE_NO_CACHE);
}
#else /* CONFIG_PHYS_64BIT */
void __iomem *
ioremap64(unsigned long long addr, unsigned long size)
{
return __ioremap(addr, size, _PAGE_NO_CACHE);
}
void __iomem *
ioremap(phys_addr_t addr, unsigned long size)
{
phys_addr_t addr64 = fixup_bigphys_addr(addr, size);
return ioremap64(addr64, size);
}
#endif /* CONFIG_PHYS_64BIT */
void __iomem *
__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
{
unsigned long v, i;
phys_addr_t p;
int err;
/*
* Choose an address to map it to.
* Once the vmalloc system is running, we use it.
* Before then, we use space going down from ioremap_base
* (ioremap_bot records where we're up to).
*/
p = addr & PAGE_MASK;
size = PAGE_ALIGN(addr + size) - p;
/*
* If the address lies within the first 16 MB, assume it's in ISA
* memory space
*/
if (p < 16*1024*1024)
p += _ISA_MEM_BASE;
/*
* Don't allow anybody to remap normal RAM that we're using.
* mem_init() sets high_memory so only do the check after that.
*/
if ( mem_init_done && (p < virt_to_phys(high_memory)) )
{
printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p,
__builtin_return_address(0));
return NULL;
}
if (size == 0)
return NULL;
/*
* Is it already mapped? Perhaps overlapped by a previous
* BAT mapping. If the whole area is mapped then we're done,
* otherwise remap it since we want to keep the virt addrs for
* each request contiguous.
*
* We make the assumption here that if the bottom and top
* of the range we want are mapped then it's mapped to the
* same virt address (and this is contiguous).
* -- Cort
*/
if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
goto out;
if (mem_init_done) {
struct vm_struct *area;
area = get_vm_area(size, VM_IOREMAP);
if (area == 0)
return NULL;
v = (unsigned long) area->addr;
} else {
v = (ioremap_bot -= size);
}
if ((flags & _PAGE_PRESENT) == 0)
flags |= _PAGE_KERNEL;
if (flags & _PAGE_NO_CACHE)
flags |= _PAGE_GUARDED;
/*
* Should check if it is a candidate for a BAT mapping
*/
err = 0;
for (i = 0; i < size && err == 0; i += PAGE_SIZE)
err = map_page(v+i, p+i, flags);
if (err) {
if (mem_init_done)
vunmap((void *)v);
return NULL;
}
out:
return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
}
void iounmap(volatile void __iomem *addr)
{
/*
* If mapped by BATs then there is nothing to do.
* Calling vfree() generates a benign warning.
*/
if (v_mapped_by_bats((unsigned long)addr)) return;
if (addr > high_memory && (unsigned long) addr < ioremap_bot)
vunmap((void *) (PAGE_MASK & (unsigned long)addr));
}
void __iomem *ioport_map(unsigned long port, unsigned int len)
{
return (void __iomem *) (port + _IO_BASE);
}
void ioport_unmap(void __iomem *addr)
{
/* Nothing to do */
}
EXPORT_SYMBOL(ioport_map);
EXPORT_SYMBOL(ioport_unmap);
int
map_page(unsigned long va, phys_addr_t pa, int flags)
{
pmd_t *pd;
pte_t *pg;
int err = -ENOMEM;
/* Use upper 10 bits of VA to index the first level map */
pd = pmd_offset(pgd_offset_k(va), va);
/* Use middle 10 bits of VA to index the second-level map */
pg = pte_alloc_kernel(pd, va);
if (pg != 0) {
err = 0;
set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags)));
if (mem_init_done)
flush_HPTE(0, va, pmd_val(*pd));
}
return err;
}
/*
* Map in all of physical memory starting at KERNELBASE.
*/
void __init mapin_ram(void)
{
unsigned long v, p, s, f;
s = mmu_mapin_ram();
v = KERNELBASE + s;
p = PPC_MEMSTART + s;
for (; s < total_lowmem; s += PAGE_SIZE) {
if ((char *) v >= _stext && (char *) v < etext)
f = _PAGE_RAM_TEXT;
else
f = _PAGE_RAM;
map_page(v, p, f);
v += PAGE_SIZE;
p += PAGE_SIZE;
}
}
/* is x a power of 4? */
#define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)
/*
* Set up a mapping for a block of I/O.
* virt, phys, size must all be page-aligned.
* This should only be called before ioremap is called.
*/
void __init io_block_mapping(unsigned long virt, phys_addr_t phys,
unsigned int size, int flags)
{
int i;
if (virt > KERNELBASE && virt < ioremap_bot)
ioremap_bot = ioremap_base = virt;
#ifdef HAVE_BATS
/*
* Use a BAT for this if possible...
*/
if (io_bat_index < 2 && is_power_of_2(size)
&& (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) {
setbat(io_bat_index, virt, phys, size, flags);
++io_bat_index;
return;
}
#endif /* HAVE_BATS */
/* No BATs available, put it in the page tables. */
for (i = 0; i < size; i += PAGE_SIZE)
map_page(virt + i, phys + i, flags);
}
/* Scan the real Linux page tables and return a PTE pointer for
* a virtual address in a context.
* Returns true (1) if PTE was found, zero otherwise. The pointer to
* the PTE pointer is unmodified if PTE is not found.
*/
int
get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
{
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
int retval = 0;
pgd = pgd_offset(mm, addr & PAGE_MASK);
if (pgd) {
pmd = pmd_offset(pgd, addr & PAGE_MASK);
if (pmd_present(*pmd)) {
pte = pte_offset_map(pmd, addr & PAGE_MASK);
if (pte) {
retval = 1;
*ptep = pte;
if (pmdp)
*pmdp = pmd;
/* XXX caller needs to do pte_unmap, yuck */
}
}
}
return(retval);
}
/* Find physical address for this virtual address. Normally used by
* I/O functions, but anyone can call it.
*/
unsigned long iopa(unsigned long addr)
{
unsigned long pa;
/* I don't know why this won't work on PMacs or CHRP. It
* appears there is some bug, or there is some implicit
* mapping done not properly represented by BATs or in page
* tables.......I am actively working on resolving this, but
* can't hold up other stuff. -- Dan
*/
pte_t *pte;
struct mm_struct *mm;
/* Check the BATs */
pa = v_mapped_by_bats(addr);
if (pa)
return pa;
/* Allow mapping of user addresses (within the thread)
* for DMA if necessary.
*/
if (addr < TASK_SIZE)
mm = current->mm;
else
mm = &init_mm;
pa = 0;
if (get_pteptr(mm, addr, &pte, NULL)) {
pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
pte_unmap(pte);
}
return(pa);
}
