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/*
* BK Id: %F% %I% %G% %U% %#%
*/
/*
* 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/config.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/io.h>
#include "mmu_decl.h"
unsigned long ram_phys_base;
unsigned long ioremap_base;
unsigned long ioremap_bot;
int io_bat_index;
/* Maximum 768Mb of lowmem. On SMP, this value will be
* trimmed down to whatever can be covered by BATs though.
*/
#define MAX_LOW_MEM 0x30000000
#ifndef CONFIG_SMP
struct pgtable_cache_struct quicklists;
#endif
#if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
#define HAVE_BATS 1
#endif
#ifdef HAVE_BATS
static unsigned long __bat2, __bat3;
#endif
extern char etext[], _stext[];
#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 */
#ifndef CONFIG_PPC_ISERIES
void *
ioremap(unsigned long addr, unsigned long size)
{
return __ioremap(addr, size, _PAGE_NO_CACHE);
}
void *
__ioremap(unsigned long addr, unsigned long size, unsigned long flags)
{
unsigned long p, v, i;
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 %0lx 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 = VMALLOC_VMADDR(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)
vfree((void *)v);
return NULL;
}
out:
return (void *) (v + (addr & ~PAGE_MASK));
}
void iounmap(void *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)
vfree((void *) (PAGE_MASK & (unsigned long) addr));
}
#endif /* CONFIG_PPC_ISERIES */
int
map_page(unsigned long va, unsigned long pa, int flags)
{
pmd_t *pd;
pte_t *pg;
int err = -ENOMEM;
spin_lock(&init_mm.page_table_lock);
/* 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(&init_mm, pd, va);
if (pg != 0) {
err = 0;
set_pte(pg, mk_pte_phys(pa & PAGE_MASK, __pgprot(flags)));
if (mem_init_done)
flush_HPTE(0, va, pg);
}
spin_unlock(&init_mm.page_table_lock);
return err;
}
void __init
adjust_total_lowmem(void)
{
unsigned long max_low_mem = MAX_LOW_MEM;
#ifdef HAVE_BATS
unsigned long bat_max = 0x10000000;
unsigned long align;
unsigned long ram = total_lowmem;
int is601 = 0;
/* 601s have smaller BATs */
if (PVR_VER(mfspr(PVR)) == 1) {
bat_max = 0x00800000;
is601 = 1;
}
/* Make sure we don't map a block larger than the
smallest alignment of the physical address. */
/* alignment of ram_phys_base */
align = ~(ram_phys_base-1) & ram_phys_base;
/* set BAT block size to MIN(max_size, align) */
if (align && align < bat_max)
bat_max = align;
/* Calculate BAT values */
__bat2 = 1UL << __ilog2(ram);
if (__bat2 > bat_max)
__bat2 = bat_max;
ram -= __bat2;
if (ram) {
__bat3 = 1UL << __ilog2(ram);
if (__bat3 > bat_max)
__bat3 = bat_max;
ram -= __bat3;
}
printk(KERN_INFO "Memory BAT mapping: BAT2=%ldMb, BAT3=%ldMb, residual: %ldMb\n",
__bat2 >> 20, __bat3 >> 20, ram >> 20);
/* On SMP, we limit the lowmem to the area mapped with BATs.
* We also assume nobody will do SMP with 601s
*/
#ifdef CONFIG_SMP
if (!is601)
max_low_mem = __bat2 + __bat3;
#endif /* CONFIG_SMP */
#endif /* HAVE_BATS */
if (total_lowmem > max_low_mem) {
total_lowmem = max_low_mem;
#ifndef CONFIG_HIGHMEM
printk(KERN_INFO "Warning, memory limited to %ld Mb, use CONFIG_HIGHMEM"
" to reach %ld Mb\n", max_low_mem >> 20, total_lowmem >> 20);
total_memory = total_lowmem;
#endif /* CONFIG_HIGHMEM */
}
}
/*
* Map in all of physical memory starting at KERNELBASE.
*/
void __init mapin_ram(void)
{
unsigned long v, p, s, f;
#ifdef HAVE_BATS
if (!__map_without_bats)
bat_mapin_ram(__bat2, __bat3);
#endif /* HAVE_BATS */
v = KERNELBASE;
p = ram_phys_base;
for (s = 0; s < total_lowmem; s += PAGE_SIZE) {
/* On the MPC8xx, we want the page shared so we
* don't get ASID compares on kernel space.
*/
f = _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_SHARED;
#if defined(CONFIG_KGDB) || defined(CONFIG_XMON)
/* Allows stub to set breakpoints everywhere */
f |= _PAGE_RW | _PAGE_DIRTY;
#else
if ((char *) v < _stext || (char *) v >= etext)
f |= _PAGE_RW | _PAGE_DIRTY;
#ifdef CONFIG_PPC_STD_MMU
else
/* On the powerpc (not all), no user access
forces R/W kernel access */
f |= _PAGE_USER;
#endif /* CONFIG_PPC_STD_MMU */
#endif /* CONFIG_KGDB */
map_page(v, p, f);
v += PAGE_SIZE;
p += PAGE_SIZE;
}
}
/* is x a power of 2? */
#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
/*
* 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, unsigned long 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)
{
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(pmd, addr & PAGE_MASK);
if (pte) {
retval = 1;
*ptep = pte;
}
}
}
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))
pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);
return(pa);
}
/* This is will find the virtual address for a physical one....
* Swiped from APUS, could be dangerous :-).
* This is only a placeholder until I really find a way to make this
* work. -- Dan
*/
unsigned long
mm_ptov (unsigned long paddr)
{
unsigned long ret;
#if 0
if (paddr < 16*1024*1024)
ret = ZTWO_VADDR(paddr);
else {
int i;
for (i = 0; i < kmap_chunk_count;){
unsigned long phys = kmap_chunks[i++];
unsigned long size = kmap_chunks[i++];
unsigned long virt = kmap_chunks[i++];
if (paddr >= phys
&& paddr < (phys + size)){
ret = virt + paddr - phys;
goto exit;
}
}
ret = (unsigned long) __va(paddr);
}
exit:
#ifdef DEBUGPV
printk ("PTOV(%lx)=%lx\n", paddr, ret);
#endif
#else
ret = (unsigned long)paddr + KERNELBASE;
#endif
return ret;
}
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