286 lines
6.3 KiB
C
286 lines
6.3 KiB
C
/*
|
|
* 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++;
|
|
}
|
|
}
|
|
|
|
|