/*
* PowerPC version
* 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).
* PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
*
* 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/module.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/btext.h>
#include <asm/tlb.h>
#include <asm/bootinfo.h>
#include <asm/prom.h>
#include "mem_pieces.h"
#include "mmu_decl.h"
#if defined(CONFIG_KERNEL_START_BOOL) || defined(CONFIG_LOWMEM_SIZE_BOOL)
/* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
#endif
#endif
#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
unsigned long total_memory;
unsigned long total_lowmem;
unsigned long ppc_memstart;
unsigned long ppc_memoffset = PAGE_OFFSET;
int mem_init_done;
int init_bootmem_done;
int boot_mapsize;
#ifdef CONFIG_PPC_PMAC
unsigned long agp_special_page;
#endif
extern char _end[];
extern char etext[], _stext[];
extern char __init_begin, __init_end;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);
EXPORT_SYMBOL(kmap_pte);
#endif
void MMU_init(void);
void set_phys_avail(unsigned long total_ram);
/* XXX should be in current.h -- paulus */
extern struct task_struct *current_set[NR_CPUS];
char *klimit = _end;
struct mem_pieces phys_avail;
struct device_node *memory_node;
/*
* this tells the system to map all of ram with the segregs
* (i.e. page tables) instead of the bats.
* -- Cort
*/
int __map_without_bats;
int __map_without_ltlbs;
/* max amount of RAM to use */
unsigned long __max_memory;
/* max amount of low RAM to map in */
unsigned long __max_low_memory = MAX_LOW_MEM;
/*
* Read in a property describing some pieces of memory.
*/
static int __init get_mem_prop(char *name, struct mem_pieces *mp)
{
struct reg_property *rp;
int i, s;
unsigned int *ip;
int nac = prom_n_addr_cells(memory_node);
int nsc = prom_n_size_cells(memory_node);
ip = (unsigned int *) get_property(memory_node, name, &s);
if (ip == NULL) {
printk(KERN_ERR "error: couldn't get %s property on /memory\n",
name);
return 0;
}
s /= (nsc + nac) * 4;
rp = mp->regions;
for (i = 0; i < s; ++i, ip += nac+nsc) {
if (nac >= 2 && ip[nac-2] != 0)
continue;
rp->address = ip[nac-1];
if (nsc >= 2 && ip[nac+nsc-2] != 0)
rp->size = ~0U;
else
rp->size = ip[nac+nsc-1];
++rp;
}
mp->n_regions = rp - mp->regions;
/* Make sure the pieces are sorted. */
mem_pieces_sort(mp);
mem_pieces_coalesce(mp);
return 1;
}
/*
* Collect information about physical RAM and which pieces are
* already in use from the device tree.
*/
unsigned long __init find_end_of_memory(void)
{
unsigned long a, total;
struct mem_pieces phys_mem;
/*
* Find out where physical memory is, and check that it
* starts at 0 and is contiguous. It seems that RAM is
* always physically contiguous on Power Macintoshes.
*
* Supporting discontiguous physical memory isn't hard,
* it just makes the virtual <-> physical mapping functions
* more complicated (or else you end up wasting space
* in mem_map).
*/
memory_node = find_devices("memory");
if (memory_node == NULL || !get_mem_prop("reg", &phys_mem)
|| phys_mem.n_regions == 0)
panic("No RAM??");
a = phys_mem.regions[0].address;
if (a != 0)
panic("RAM doesn't start at physical address 0");
total = phys_mem.regions[0].size;
if (phys_mem.n_regions > 1) {
printk("RAM starting at 0x%x is not contiguous\n",
phys_mem.regions[1].address);
printk("Using RAM from 0 to 0x%lx\n", total-1);
}
return total;
}
/*
* Check for command-line options that affect what MMU_init will do.
*/
void MMU_setup(void)
{
/* Check for nobats option (used in mapin_ram). */
if (strstr(cmd_line, "nobats")) {
__map_without_bats = 1;
}
if (strstr(cmd_line, "noltlbs")) {
__map_without_ltlbs = 1;
}
/* Look for mem= option on command line */
if (strstr(cmd_line, "mem=")) {
char *p, *q;
unsigned long maxmem = 0;
for (q = cmd_line; (p = strstr(q, "mem=")) != 0; ) {
q = p + 4;
if (p > cmd_line && p[-1] != ' ')
continue;
maxmem = simple_strtoul(q, &q, 0);
if (*q == 'k' || *q == 'K') {
maxmem <<= 10;
++q;
} else if (*q == 'm' || *q == 'M') {
maxmem <<= 20;
++q;
}
}
__max_memory = maxmem;
}
}
/*
* MMU_init sets up the basic memory mappings for the kernel,
* including both RAM and possibly some I/O regions,
* and sets up the page tables and the MMU hardware ready to go.
*/
void __init MMU_init(void)
{
if (ppc_md.progress)
ppc_md.progress("MMU:enter", 0x111);
/* parse args from command line */
MMU_setup();
/*
* Figure out how much memory we have, how much
* is lowmem, and how much is highmem. If we were
* passed the total memory size from the bootloader,
* just use it.
*/
if (boot_mem_size)
total_memory = boot_mem_size;
else
total_memory = find_end_of_memory();
if (__max_memory && total_memory > __max_memory)
total_memory = __max_memory;
total_lowmem = total_memory;
#ifdef CONFIG_FSL_BOOKE
/* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
* entries, so we need to adjust lowmem to match the amount we can map
* in the fixed entries */
adjust_total_lowmem();
#endif /* CONFIG_FSL_BOOKE */
if (total_lowmem > __max_low_memory) {
total_lowmem = __max_low_memory;
#ifndef CONFIG_HIGHMEM
total_memory = total_lowmem;
#endif /* CONFIG_HIGHMEM */
}
set_phys_avail(total_lowmem);
/* Initialize the MMU hardware */
if (ppc_md.progress)
ppc_md.progress("MMU:hw init", 0x300);
MMU_init_hw();
/* Map in all of RAM starting at KERNELBASE */
if (ppc_md.progress)
ppc_md.progress("MMU:mapin", 0x301);
mapin_ram();
#ifdef CONFIG_HIGHMEM
ioremap_base = PKMAP_BASE;
#else
ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
#endif /* CONFIG_HIGHMEM */
ioremap_bot = ioremap_base;
/* Map in I/O resources */
if (ppc_md.progress)
ppc_md.progress("MMU:setio", 0x302);
if (ppc_md.setup_io_mappings)
ppc_md.setup_io_mappings();
/* Initialize the context management stuff */
mmu_context_init();
if (ppc_md.progress)
ppc_md.progress("MMU:exit", 0x211);
#ifdef CONFIG_BOOTX_TEXT
/* By default, we are no longer mapped */
boot_text_mapped = 0;
/* Must be done last, or ppc_md.progress will die. */
map_boot_text();
#endif
}
/* This is only called until mem_init is done. */
void __init *early_get_page(void)
{
void *p;
if (init_bootmem_done) {
p = alloc_bootmem_pages(PAGE_SIZE);
} else {
p = mem_pieces_find(PAGE_SIZE, PAGE_SIZE);
}
return p;
}
/* Free up now-unused memory */
static void free_sec(unsigned long start, unsigned long end, const char *name)
{
unsigned long cnt = 0;
while (start < end) {
ClearPageReserved(virt_to_page(start));
set_page_count(virt_to_page(start), 1);
free_page(start);
cnt++;
start += PAGE_SIZE;
}
if (cnt) {
printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
totalram_pages += cnt;
}
}
void free_initmem(void)
{
#define FREESEC(TYPE) \
free_sec((unsigned long)(&__ ## TYPE ## _begin), \
(unsigned long)(&__ ## TYPE ## _end), \
#TYPE);
printk ("Freeing unused kernel memory:");
FREESEC(init);
printk("\n");
ppc_md.progress = NULL;
#undef FREESEC
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (start < end)
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
set_page_count(virt_to_page(start), 1);
free_page(start);
totalram_pages++;
}
}
#endif
/*
* Initialize the bootmem system and give it all the memory we
* have available.
*/
void __init do_init_bootmem(void)
{
unsigned long start, size;
int i;
/*
* Find an area to use for the bootmem bitmap.
* We look for the first area which is at least
* 128kB in length (128kB is enough for a bitmap
* for 4GB of memory, using 4kB pages), plus 1 page
* (in case the address isn't page-aligned).
*/
start = 0;
size = 0;
for (i = 0; i < phys_avail.n_regions; ++i) {
unsigned long a = phys_avail.regions[i].address;
unsigned long s = phys_avail.regions[i].size;
if (s <= size)
continue;
start = a;
size = s;
if (s >= 33 * PAGE_SIZE)
break;
}
start = PAGE_ALIGN(start);
min_low_pfn = start >> PAGE_SHIFT;
max_low_pfn = (PPC_MEMSTART + total_lowmem) >> PAGE_SHIFT;
max_pfn = (PPC_MEMSTART + total_memory) >> PAGE_SHIFT;
boot_mapsize = init_bootmem_node(&contig_page_data, min_low_pfn,
PPC_MEMSTART >> PAGE_SHIFT,
max_low_pfn);
/* remove the bootmem bitmap from the available memory */
mem_pieces_remove(&phys_avail, start, boot_mapsize, 1);
/* add everything in phys_avail into the bootmem map */
for (i = 0; i < phys_avail.n_regions; ++i)
free_bootmem(phys_avail.regions[i].address,
phys_avail.regions[i].size);
init_bootmem_done = 1;
}
/*
* paging_init() sets up the page tables - in fact we've already done this.
*/
void __init paging_init(void)
{
unsigned long zones_size[MAX_NR_ZONES], i;
#ifdef CONFIG_HIGHMEM
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
(PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
(KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */
/*
* All pages are DMA-able so we put them all in the DMA zone.
*/
zones_size[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
for (i = 1; i < MAX_NR_ZONES; i++)
zones_size[i] = 0;
#ifdef CONFIG_HIGHMEM
zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */
free_area_init(zones_size);
}
void __init mem_init(void)
{
unsigned long addr;
int codepages = 0;
int datapages = 0;
int initpages = 0;
#ifdef CONFIG_HIGHMEM
unsigned long highmem_mapnr;
highmem_mapnr = total_lowmem >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */
max_mapnr = total_memory >> PAGE_SHIFT;
high_memory = (void *) __va(PPC_MEMSTART + total_lowmem);
num_physpages = max_mapnr; /* RAM is assumed contiguous */
totalram_pages += free_all_bootmem();
#ifdef CONFIG_BLK_DEV_INITRD
/* if we are booted from BootX with an initial ramdisk,
make sure the ramdisk pages aren't reserved. */
if (initrd_start) {
for (addr = initrd_start; addr < initrd_end; addr += PAGE_SIZE)
ClearPageReserved(virt_to_page(addr));
}
#endif /* CONFIG_BLK_DEV_INITRD */
#ifdef CONFIG_PPC_OF
/* mark the RTAS pages as reserved */
if ( rtas_data )
for (addr = (ulong)__va(rtas_data);
addr < PAGE_ALIGN((ulong)__va(rtas_data)+rtas_size) ;
addr += PAGE_SIZE)
SetPageReserved(virt_to_page(addr));
#endif
#ifdef CONFIG_PPC_PMAC
if (agp_special_page)
SetPageReserved(virt_to_page(agp_special_page));
#endif
for (addr = PAGE_OFFSET; addr < (unsigned long)high_memory;
addr += PAGE_SIZE) {
if (!PageReserved(virt_to_page(addr)))
continue;
if (addr < (ulong) etext)
codepages++;
else if (addr >= (unsigned long)&__init_begin
&& addr < (unsigned long)&__init_end)
initpages++;
else if (addr < (ulong) klimit)
datapages++;
}
#ifdef CONFIG_HIGHMEM
{
unsigned long pfn;
for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
struct page *page = mem_map + pfn;
ClearPageReserved(page);
set_page_count(page, 1);
__free_page(page);
totalhigh_pages++;
}
totalram_pages += totalhigh_pages;
}
#endif /* CONFIG_HIGHMEM */
printk("Memory: %luk available (%dk kernel code, %dk data, %dk init, %ldk highmem)\n",
(unsigned long)nr_free_pages()<< (PAGE_SHIFT-10),
codepages<< (PAGE_SHIFT-10), datapages<< (PAGE_SHIFT-10),
initpages<< (PAGE_SHIFT-10),
(unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
#ifdef CONFIG_PPC_PMAC
if (agp_special_page)
printk(KERN_INFO "AGP special page: 0x%08lx\n", agp_special_page);
#endif
mem_init_done = 1;
}
/*
* Set phys_avail to the amount of physical memory,
* less the kernel text/data/bss.
*/
void __init
set_phys_avail(unsigned long total_memory)
{
unsigned long kstart, ksize;
/*
* Initially, available physical memory is equivalent to all
* physical memory.
*/
phys_avail.regions[0].address = PPC_MEMSTART;
phys_avail.regions[0].size = total_memory;
phys_avail.n_regions = 1;
/*
* Map out the kernel text/data/bss from the available physical
* memory.
*/
kstart = __pa(_stext); /* should be 0 */
ksize = PAGE_ALIGN(klimit - _stext);
mem_pieces_remove(&phys_avail, kstart, ksize, 0);
mem_pieces_remove(&phys_avail, 0, 0x4000, 0);
#if defined(CONFIG_BLK_DEV_INITRD)
/* Remove the init RAM disk from the available memory. */
if (initrd_start) {
mem_pieces_remove(&phys_avail, __pa(initrd_start),
initrd_end - initrd_start, 1);
}
#endif /* CONFIG_BLK_DEV_INITRD */
#ifdef CONFIG_PPC_OF
/* remove the RTAS pages from the available memory */
if (rtas_data)
mem_pieces_remove(&phys_avail, rtas_data, rtas_size, 1);
#endif
#ifdef CONFIG_PPC_PMAC
/* Because of some uninorth weirdness, we need a page of
* memory as high as possible (it must be outside of the
* bus address seen as the AGP aperture). It will be used
* by the r128 DRM driver
*
* FIXME: We need to make sure that page doesn't overlap any of the\
* above. This could be done by improving mem_pieces_find to be able
* to do a backward search from the end of the list.
*/
if (_machine == _MACH_Pmac && find_devices("uni-north-agp")) {
agp_special_page = (total_memory - PAGE_SIZE);
mem_pieces_remove(&phys_avail, agp_special_page, PAGE_SIZE, 0);
agp_special_page = (unsigned long)__va(agp_special_page);
}
#endif /* CONFIG_PPC_PMAC */
}
/* Mark some memory as reserved by removing it from phys_avail. */
void __init reserve_phys_mem(unsigned long start, unsigned long size)
{
mem_pieces_remove(&phys_avail, start, size, 1);
}
