[deliverable/linux.git] / arch / powerpc / mm / init_32.c

/*
 *  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
 *  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/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/prom.h>
#include <asm/lmb.h>
#include <asm/sections.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 boot_mapsize;
#ifdef CONFIG_PPC_PMAC
unsigned long agp_special_page;
EXPORT_SYMBOL(agp_special_page);
#endif

#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;

EXPORT_SYMBOL(kmap_prot);
EXPORT_SYMBOL(kmap_pte);
#endif

void MMU_init(void);

/* XXX should be in current.h  -- paulus */
extern struct task_struct *current_set[NR_CPUS];

extern int init_bootmem_done;

/*
 * 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 low RAM to map in */
unsigned long __max_low_memory = MAX_LOW_MEM;

/*
 * limit of what is accessible with initial MMU setup -
 * 256MB usually, but only 16MB on 601.
 */
unsigned long __initial_memory_limit = 0x10000000;

/*
 * 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;
	}
#ifdef CONFIG_DEBUG_PAGEALLOC
	__map_without_bats = 1;
	__map_without_ltlbs = 1;
#endif
}

/*
 * 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);

	/* 601 can only access 16MB at the moment */
	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
		__initial_memory_limit = 0x01000000;

	/* parse args from command line */
	MMU_setup();

	if (lmb.memory.cnt > 1) {
		lmb.memory.cnt = 1;
		lmb_analyze();
		printk(KERN_WARNING "Only using first contiguous memory region");
	}

	total_memory = lmb_end_of_DRAM();
	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;
		lmb_enforce_memory_limit(total_lowmem);
		lmb_analyze();
#endif /* CONFIG_HIGHMEM */
	}

	/* 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);

	/* From now on, btext is no longer BAT mapped if it was at all */
#ifdef CONFIG_BOOTX_TEXT
	btext_unmap();
#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 = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
					__initial_memory_limit));
	}
	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));
		init_page_count(virt_to_page(start));
		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));
		init_page_count(virt_to_page(start));
		free_page(start);
		totalram_pages++;
	}
}
#endif
Commit	Line	Data
14cf11af PM	1	/*
	2	* PowerPC version
	3	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	4	*
	5	* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
	6	* and Cort Dougan (PReP) (cort@cs.nmt.edu)
	7	* Copyright (C) 1996 Paul Mackerras
14cf11af PM	8	* PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
	9	*
	10	* Derived from "arch/i386/mm/init.c"
	11	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
	12	*
	13	* This program is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU General Public License
	15	* as published by the Free Software Foundation; either version
	16	* 2 of the License, or (at your option) any later version.
	17	*
	18	*/
	19
14cf11af PM	20	#include <linux/module.h>
	21	#include <linux/sched.h>
	22	#include <linux/kernel.h>
	23	#include <linux/errno.h>
	24	#include <linux/string.h>
	25	#include <linux/types.h>
	26	#include <linux/mm.h>
	27	#include <linux/stddef.h>
	28	#include <linux/init.h>
	29	#include <linux/bootmem.h>
	30	#include <linux/highmem.h>
	31	#include <linux/initrd.h>
	32	#include <linux/pagemap.h>
	33
	34	#include <asm/pgalloc.h>
	35	#include <asm/prom.h>
	36	#include <asm/io.h>
	37	#include <asm/mmu_context.h>
	38	#include <asm/pgtable.h>
	39	#include <asm/mmu.h>
	40	#include <asm/smp.h>
	41	#include <asm/machdep.h>
	42	#include <asm/btext.h>
	43	#include <asm/tlb.h>
14cf11af	44	#include <asm/prom.h>
7c8c6b97 PM	45	#include <asm/lmb.h>
7c8c6b97 PM	46	#include <asm/sections.h>
14cf11af	47
14cf11af PM	48	#include "mmu_decl.h"
	49
	50	#if defined(CONFIG_KERNEL_START_BOOL) \|\| defined(CONFIG_LOWMEM_SIZE_BOOL)
	51	/* The ammount of lowmem must be within 0xF0000000 - KERNELBASE. */
	52	#if (CONFIG_LOWMEM_SIZE > (0xF0000000 - KERNELBASE))
	53	#error "You must adjust CONFIG_LOWMEM_SIZE or CONFIG_START_KERNEL"
	54	#endif
	55	#endif
	56	#define MAX_LOW_MEM CONFIG_LOWMEM_SIZE
	57
	58	DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
	59
	60	unsigned long total_memory;
	61	unsigned long total_lowmem;
	62
	63	unsigned long ppc_memstart;
	64	unsigned long ppc_memoffset = PAGE_OFFSET;
	65
14cf11af PM	66	int boot_mapsize;
	67	#ifdef CONFIG_PPC_PMAC
	68	unsigned long agp_special_page;
5c8c56eb	69	EXPORT_SYMBOL(agp_special_page);
14cf11af PM	70	#endif
14cf11af PM	71
14cf11af PM	72	#ifdef CONFIG_HIGHMEM
	73	pte_t *kmap_pte;
	74	pgprot_t kmap_prot;
	75
	76	EXPORT_SYMBOL(kmap_prot);
	77	EXPORT_SYMBOL(kmap_pte);
	78	#endif
	79
	80	void MMU_init(void);
14cf11af PM	81
	82	/* XXX should be in current.h -- paulus */
	83	extern struct task_struct *current_set[NR_CPUS];
	84
7c8c6b97 PM	85	extern int init_bootmem_done;
7c8c6b97 PM	86
14cf11af PM	87	/*
	88	* this tells the system to map all of ram with the segregs
	89	* (i.e. page tables) instead of the bats.
	90	* -- Cort
	91	*/
	92	int __map_without_bats;
	93	int __map_without_ltlbs;
	94
14cf11af PM	95	/* max amount of low RAM to map in */
	96	unsigned long __max_low_memory = MAX_LOW_MEM;
	97
	98	/*
7c8c6b97 PM	99	* limit of what is accessible with initial MMU setup -
7c8c6b97 PM	100	* 256MB usually, but only 16MB on 601.
14cf11af	101	*/
7c8c6b97	102	unsigned long __initial_memory_limit = 0x10000000;
14cf11af PM	103
	104	/*
	105	* Check for command-line options that affect what MMU_init will do.
	106	*/
	107	void MMU_setup(void)
	108	{
	109	/* Check for nobats option (used in mapin_ram). */
	110	if (strstr(cmd_line, "nobats")) {
	111	__map_without_bats = 1;
	112	}
	113
	114	if (strstr(cmd_line, "noltlbs")) {
	115	__map_without_ltlbs = 1;
	116	}
88df6e90 BH	117	#ifdef CONFIG_DEBUG_PAGEALLOC
	118	__map_without_bats = 1;
	119	__map_without_ltlbs = 1;
	120	#endif
14cf11af PM	121	}
	122
	123	/*
	124	* MMU_init sets up the basic memory mappings for the kernel,
	125	* including both RAM and possibly some I/O regions,
	126	* and sets up the page tables and the MMU hardware ready to go.
	127	*/
	128	void __init MMU_init(void)
	129	{
	130	if (ppc_md.progress)
	131	ppc_md.progress("MMU:enter", 0x111);
	132
7c8c6b97 PM	133	/* 601 can only access 16MB at the moment */
	134	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
	135	__initial_memory_limit = 0x01000000;
	136
14cf11af PM	137	/* parse args from command line */
	138	MMU_setup();
	139
7c8c6b97 PM	140	if (lmb.memory.cnt > 1) {
	141	lmb.memory.cnt = 1;
	142	lmb_analyze();
	143	printk(KERN_WARNING "Only using first contiguous memory region");
	144	}
	145
	146	total_memory = lmb_end_of_DRAM();
14cf11af	147	total_lowmem = total_memory;
7c8c6b97	148
14cf11af PM	149	#ifdef CONFIG_FSL_BOOKE
	150	/* Freescale Book-E parts expect lowmem to be mapped by fixed TLB
	151	* entries, so we need to adjust lowmem to match the amount we can map
	152	* in the fixed entries */
	153	adjust_total_lowmem();
	154	#endif /* CONFIG_FSL_BOOKE */
fa39dc43	155
14cf11af PM	156	if (total_lowmem > __max_low_memory) {
	157	total_lowmem = __max_low_memory;
	158	#ifndef CONFIG_HIGHMEM
	159	total_memory = total_lowmem;
fa39dc43 PM	160	lmb_enforce_memory_limit(total_lowmem);
fa39dc43 PM	161	lmb_analyze();
14cf11af PM	162	#endif /* CONFIG_HIGHMEM */
14cf11af PM	163	}
14cf11af PM	164
	165	/* Initialize the MMU hardware */
	166	if (ppc_md.progress)
	167	ppc_md.progress("MMU:hw init", 0x300);
	168	MMU_init_hw();
	169
	170	/* Map in all of RAM starting at KERNELBASE */
	171	if (ppc_md.progress)
	172	ppc_md.progress("MMU:mapin", 0x301);
	173	mapin_ram();
	174
	175	#ifdef CONFIG_HIGHMEM
	176	ioremap_base = PKMAP_BASE;
	177	#else
	178	ioremap_base = 0xfe000000UL; /* for now, could be 0xfffff000 */
	179	#endif /* CONFIG_HIGHMEM */
	180	ioremap_bot = ioremap_base;
	181
	182	/* Map in I/O resources */
	183	if (ppc_md.progress)
	184	ppc_md.progress("MMU:setio", 0x302);
	185	if (ppc_md.setup_io_mappings)
	186	ppc_md.setup_io_mappings();
	187
	188	/* Initialize the context management stuff */
	189	mmu_context_init();
	190
	191	if (ppc_md.progress)
	192	ppc_md.progress("MMU:exit", 0x211);
51d3082f BH	193
	194	/* From now on, btext is no longer BAT mapped if it was at all */
	195	#ifdef CONFIG_BOOTX_TEXT
	196	btext_unmap();
	197	#endif
14cf11af PM	198	}
	199
	200	/* This is only called until mem_init is done. */
	201	void __init *early_get_page(void)
	202	{
	203	void *p;
	204
	205	if (init_bootmem_done) {
	206	p = alloc_bootmem_pages(PAGE_SIZE);
	207	} else {
7c8c6b97 PM	208	p = __va(lmb_alloc_base(PAGE_SIZE, PAGE_SIZE,
7c8c6b97 PM	209	__initial_memory_limit));
14cf11af PM	210	}
	211	return p;
	212	}
	213
	214	/* Free up now-unused memory */
	215	static void free_sec(unsigned long start, unsigned long end, const char *name)
	216	{
	217	unsigned long cnt = 0;
	218
	219	while (start < end) {
	220	ClearPageReserved(virt_to_page(start));
7835e98b	221	init_page_count(virt_to_page(start));
14cf11af PM	222	free_page(start);
	223	cnt++;
	224	start += PAGE_SIZE;
	225	}
	226	if (cnt) {
	227	printk(" %ldk %s", cnt << (PAGE_SHIFT - 10), name);
	228	totalram_pages += cnt;
	229	}
	230	}
	231
	232	void free_initmem(void)
	233	{
	234	#define FREESEC(TYPE) \
	235	free_sec((unsigned long)(&__ ## TYPE ## _begin), \
	236	(unsigned long)(&__ ## TYPE ## _end), \
	237	#TYPE);
	238
	239	printk ("Freeing unused kernel memory:");
	240	FREESEC(init);
	241	printk("\n");
	242	ppc_md.progress = NULL;
	243	#undef FREESEC
	244	}
	245
	246	#ifdef CONFIG_BLK_DEV_INITRD
	247	void free_initrd_mem(unsigned long start, unsigned long end)
	248	{
	249	if (start < end)
	250	printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
	251	for (; start < end; start += PAGE_SIZE) {
	252	ClearPageReserved(virt_to_page(start));
7835e98b	253	init_page_count(virt_to_page(start));
14cf11af PM	254	free_page(start);
	255	totalram_pages++;
	256	}
	257	}
	258	#endif