/*
* linux/arch/m68k/motorola.c
*
* Routines specific to the Motorola MMU, originally from:
* linux/arch/m68k/init.c
* which are Copyright (C) 1995 Hamish Macdonald
*
* Moved 8/20/1999 Sam Creasey
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/dma.h>
#ifdef CONFIG_ATARI
#include <asm/atari_stram.h>
#endif
#undef DEBUG
#ifndef mm_cachebits
/*
* Bits to add to page descriptors for "normal" caching mode.
* For 68020/030 this is 0.
* For 68040, this is _PAGE_CACHE040 (cachable, copyback)
*/
unsigned long mm_cachebits;
EXPORT_SYMBOL(mm_cachebits);
#endif
static pte_t * __init kernel_page_table(void)
{
pte_t *ptablep;
ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
clear_page(ptablep);
__flush_page_to_ram(ptablep);
flush_tlb_kernel_page(ptablep);
nocache_page(ptablep);
return ptablep;
}
static pmd_t *last_pgtable __initdata = NULL;
pmd_t *zero_pgtable __initdata = NULL;
static pmd_t * __init kernel_ptr_table(void)
{
if (!last_pgtable) {
unsigned long pmd, last;
int i;
/* Find the last ptr table that was used in head.S and
* reuse the remaining space in that page for further
* ptr tables.
*/
last = (unsigned long)kernel_pg_dir;
for (i = 0; i < PTRS_PER_PGD; i++) {
if (!pgd_present(kernel_pg_dir[i]))
continue;
pmd = __pgd_page(kernel_pg_dir[i]);
if (pmd > last)
last = pmd;
}
last_pgtable = (pmd_t *)last;
#ifdef DEBUG
printk("kernel_ptr_init: %p\n", last_pgtable);
#endif
}
last_pgtable += PTRS_PER_PMD;
if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
clear_page(last_pgtable);
__flush_page_to_ram(last_pgtable);
flush_tlb_kernel_page(last_pgtable);
nocache_page(last_pgtable);
}
return last_pgtable;
}
static unsigned long __init
map_chunk (unsigned long addr, long size)
{
#define PTRTREESIZE (256*1024)
#define ROOTTREESIZE (32*1024*1024)
static unsigned long virtaddr = PAGE_OFFSET;
unsigned long physaddr;
pgd_t *pgd_dir;
pmd_t *pmd_dir;
pte_t *pte_dir;
physaddr = (addr | m68k_supervisor_cachemode |
_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
if (CPU_IS_040_OR_060)
physaddr |= _PAGE_GLOBAL040;
while (size > 0) {
#ifdef DEBUG
if (!(virtaddr & (PTRTREESIZE-1)))
printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
virtaddr);
#endif
pgd_dir = pgd_offset_k(virtaddr);
if (virtaddr && CPU_IS_020_OR_030) {
if (!(virtaddr & (ROOTTREESIZE-1)) &&
size >= ROOTTREESIZE) {
#ifdef DEBUG
printk ("[very early term]");
#endif
pgd_val(*pgd_dir) = physaddr;
size -= ROOTTREESIZE;
virtaddr += ROOTTREESIZE;
physaddr += ROOTTREESIZE;
continue;
}
}
if (!pgd_present(*pgd_dir)) {
pmd_dir = kernel_ptr_table();
#ifdef DEBUG
printk ("[new pointer %p]", pmd_dir);
#endif
pgd_set(pgd_dir, pmd_dir);
} else
pmd_dir = pmd_offset(pgd_dir, virtaddr);
if (CPU_IS_020_OR_030) {
if (virtaddr) {
#ifdef DEBUG
printk ("[early term]");
#endif
pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
physaddr += PTRTREESIZE;
} else {
int i;
#ifdef DEBUG
printk ("[zero map]");
#endif
zero_pgtable = kernel_ptr_table();
pte_dir = (pte_t *)zero_pgtable;
pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
_PAGE_TABLE | _PAGE_ACCESSED;
pte_val(*pte_dir++) = 0;
physaddr += PAGE_SIZE;
for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
pte_val(*pte_dir++) = physaddr;
}
size -= PTRTREESIZE;
virtaddr += PTRTREESIZE;
} else {
if (!pmd_present(*pmd_dir)) {
#ifdef DEBUG
printk ("[new table]");
#endif
pte_dir = kernel_page_table();
pmd_set(pmd_dir, pte_dir);
}
pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
if (virtaddr) {
if (!pte_present(*pte_dir))
pte_val(*pte_dir) = physaddr;
} else
pte_val(*pte_dir) = 0;
size -= PAGE_SIZE;
virtaddr += PAGE_SIZE;
physaddr += PAGE_SIZE;
}
}
#ifdef DEBUG
printk("\n");
#endif
return virtaddr;
}
/*
* paging_init() continues the virtual memory environment setup which
* was begun by the code in arch/head.S.
*/
void __init paging_init(void)
{
int chunk;
unsigned long mem_avail = 0;
unsigned long zones_size[3] = { 0, };
#ifdef DEBUG
{
extern unsigned long availmem;
printk ("start of paging_init (%p, %lx, %lx, %lx)\n",
kernel_pg_dir, availmem, start_mem, end_mem);
}
#endif
/* Fix the cache mode in the page descriptors for the 680[46]0. */
if (CPU_IS_040_OR_060) {
int i;
#ifndef mm_cachebits
mm_cachebits = _PAGE_CACHE040;
#endif
for (i = 0; i < 16; i++)
pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
}
/*
* Map the physical memory available into the kernel virtual
* address space. It may allocate some memory for page
* tables and thus modify availmem.
*/
for (chunk = 0; chunk < m68k_num_memory; chunk++) {
mem_avail = map_chunk (m68k_memory[chunk].addr,
m68k_memory[chunk].size);
}
flush_tlb_all();
#ifdef DEBUG
printk ("memory available is %ldKB\n", mem_avail >> 10);
printk ("start_mem is %#lx\nvirtual_end is %#lx\n",
start_mem, end_mem);
#endif
/*
* initialize the bad page table and bad page to point
* to a couple of allocated pages
*/
empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
memset(empty_zero_page, 0, PAGE_SIZE);
/*
* Set up SFC/DFC registers
*/
set_fs(KERNEL_DS);
#ifdef DEBUG
printk ("before free_area_init\n");
#endif
zones_size[0] = (mach_max_dma_address < (unsigned long)high_memory ?
(mach_max_dma_address+1) : (unsigned long)high_memory);
zones_size[1] = (unsigned long)high_memory - zones_size[0];
zones_size[0] = (zones_size[0] - PAGE_OFFSET) >> PAGE_SHIFT;
zones_size[1] >>= PAGE_SHIFT;
free_area_init(zones_size);
}
extern char __init_begin, __init_end;
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)&__init_begin;
for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) {
virt_to_page(addr)->flags &= ~(1 << PG_reserved);
set_page_count(virt_to_page(addr), 1);
free_page(addr);
totalram_pages++;
}
}
