arch/ppc/mm/init.c - kernel/msm-4.9 - Gitiles

 /*
  *  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 "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;

 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;

 /*
  * 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;

 void show_mem(void)
 {
 	int i,free = 0,total = 0,reserved = 0;
 	int shared = 0, cached = 0;
 	int highmem = 0;

 	printk("Mem-info:\n");
 	show_free_areas();
 	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 	i = max_mapnr;
 	while (i-- > 0) {
 		total++;
 		if (PageHighMem(mem_map+i))
 			highmem++;
 		if (PageReserved(mem_map+i))
 			reserved++;
 		else if (PageSwapCache(mem_map+i))
 			cached++;
 		else if (!page_count(mem_map+i))
 			free++;
 		else
 			shared += page_count(mem_map+i) - 1;
 	}
 	printk("%d pages of RAM\n",total);
 	printk("%d pages of HIGHMEM\n", highmem);
 	printk("%d free pages\n",free);
 	printk("%d reserved pages\n",reserved);
 	printk("%d pages shared\n",shared);
 	printk("%d pages swap cached\n",cached);
 }

 /* 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)
 {
 	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

 /*
  * 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 = ppc_md.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;
 }

 /*
  * 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
 	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);
 			init_page_count(page);
 			__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)));

 	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
 }

 /* 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);
 }

 /*
  * This is called when a page has been modified by the kernel.
  * It just marks the page as not i-cache clean.  We do the i-cache
  * flush later when the page is given to a user process, if necessary.
  */
 void flush_dcache_page(struct page *page)
 {
 	clear_bit(PG_arch_1, &page->flags);
 }

 void flush_dcache_icache_page(struct page *page)
 {
 #ifdef CONFIG_BOOKE
 	void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
 	__flush_dcache_icache(start);
 	kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
 #elif defined(CONFIG_8xx)
 	/* On 8xx there is no need to kmap since highmem is not supported */
 	__flush_dcache_icache(page_address(page));
 #else
 	__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
 #endif

 }
 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 {
 	clear_page(page);
 	clear_bit(PG_arch_1, &pg->flags);
 }

 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 		    struct page *pg)
 {
 	copy_page(vto, vfrom);
 	clear_bit(PG_arch_1, &pg->flags);
 }

 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 			     unsigned long addr, int len)
 {
 	unsigned long maddr;

 	maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
 	flush_icache_range(maddr, maddr + len);
 	kunmap(page);
 }

 /*
  * This is called at the end of handling a user page fault, when the
  * fault has been handled by updating a PTE in the linux page tables.
  * We use it to preload an HPTE into the hash table corresponding to
  * the updated linux PTE.
  */
 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 		      pte_t pte)
 {
 	/* handle i-cache coherency */
 	unsigned long pfn = pte_pfn(pte);

 	if (pfn_valid(pfn)) {
 		struct page *page = pfn_to_page(pfn);
 #ifdef CONFIG_8xx
 		/* On 8xx, the TLB handlers work in 2 stages:
 	 	 * First, a zeroed entry is loaded by TLBMiss handler,
 		 * which causes the TLBError handler to be triggered.
 		 * That means the zeroed TLB has to be invalidated
 		 * whenever a page miss occurs.
 		 */
 		_tlbie(address);
 #endif
 		if (!PageReserved(page)
 		    && !test_bit(PG_arch_1, &page->flags)) {
 			if (vma->vm_mm == current->active_mm)
 				__flush_dcache_icache((void *) address);
 			else
 				flush_dcache_icache_page(page);
 			set_bit(PG_arch_1, &page->flags);
 		}
 	}

 #ifdef CONFIG_PPC_STD_MMU
 	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 	if (Hash != 0 && pte_young(pte)) {
 		struct mm_struct *mm;
 		pmd_t *pmd;

 		mm = (address < TASK_SIZE)? vma->vm_mm: &init_mm;
 		pmd = pmd_offset(pgd_offset(mm, address), address);
 		if (!pmd_none(*pmd))
 			add_hash_page(mm->context, address, pmd_val(*pmd));
 	}
 #endif
 }

 /*
  * This is called by /dev/mem to know if a given address has to
  * be mapped non-cacheable or not
  */
 int page_is_ram(unsigned long pfn)
 {
 	return pfn < max_pfn;
 }

 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 			      unsigned long size, pgprot_t vma_prot)
 {
 	if (ppc_md.phys_mem_access_prot)
 		return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

 	if (!page_is_ram(pfn))
 		vma_prot = __pgprot(pgprot_val(vma_prot)
 				    | _PAGE_GUARDED | _PAGE_NO_CACHE);
 	return vma_prot;
 }
 EXPORT_SYMBOL(phys_mem_access_prot);
	/*
	* 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 "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;

	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;

	/*
	* 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;

	void show_mem(void)
	{
	int i,free = 0,total = 0,reserved = 0;
	int shared = 0, cached = 0;
	int highmem = 0;

	printk("Mem-info:\n");
	show_free_areas();
	printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
	i = max_mapnr;
	while (i-- > 0) {
	total++;
	if (PageHighMem(mem_map+i))
	highmem++;
	if (PageReserved(mem_map+i))
	reserved++;
	else if (PageSwapCache(mem_map+i))
	cached++;
	else if (!page_count(mem_map+i))
	free++;
	else
	shared += page_count(mem_map+i) - 1;
	}
	printk("%d pages of RAM\n",total);
	printk("%d pages of HIGHMEM\n", highmem);
	printk("%d free pages\n",free);
	printk("%d reserved pages\n",reserved);
	printk("%d pages shared\n",shared);
	printk("%d pages swap cached\n",cached);
	}

	/* 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)
	{
	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

	/*
	* 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 = ppc_md.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;
	}

	/*
	* 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
	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);
	init_page_count(page);
	__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)));

	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
	}

	/* 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);
	}

	/*
	* This is called when a page has been modified by the kernel.
	* It just marks the page as not i-cache clean. We do the i-cache
	* flush later when the page is given to a user process, if necessary.
	*/
	void flush_dcache_page(struct page *page)
	{
	clear_bit(PG_arch_1, &page->flags);
	}

	void flush_dcache_icache_page(struct page *page)
	{
	#ifdef CONFIG_BOOKE
	void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
	__flush_dcache_icache(start);
	kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
	#elif defined(CONFIG_8xx)
	/* On 8xx there is no need to kmap since highmem is not supported */
	__flush_dcache_icache(page_address(page));
	#else
	__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
	#endif

	}
	void clear_user_page(void page, unsigned long vaddr, struct page pg)
	{
	clear_page(page);
	clear_bit(PG_arch_1, &pg->flags);
	}

	void copy_user_page(void vto, void vfrom, unsigned long vaddr,
	struct page *pg)
	{
	copy_page(vto, vfrom);
	clear_bit(PG_arch_1, &pg->flags);
	}

	void flush_icache_user_range(struct vm_area_struct vma, struct page page,
	unsigned long addr, int len)
	{
	unsigned long maddr;

	maddr = (unsigned long) kmap(page) + (addr & ~PAGE_MASK);
	flush_icache_range(maddr, maddr + len);
	kunmap(page);
	}

	/*
	* This is called at the end of handling a user page fault, when the
	* fault has been handled by updating a PTE in the linux page tables.
	* We use it to preload an HPTE into the hash table corresponding to
	* the updated linux PTE.
	*/
	void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
	pte_t pte)
	{
	/* handle i-cache coherency */
	unsigned long pfn = pte_pfn(pte);

	if (pfn_valid(pfn)) {
	struct page *page = pfn_to_page(pfn);
	#ifdef CONFIG_8xx
	/* On 8xx, the TLB handlers work in 2 stages:
	* First, a zeroed entry is loaded by TLBMiss handler,
	* which causes the TLBError handler to be triggered.
	* That means the zeroed TLB has to be invalidated
	* whenever a page miss occurs.
	*/
	_tlbie(address);
	#endif
	if (!PageReserved(page)
	&& !test_bit(PG_arch_1, &page->flags)) {
	if (vma->vm_mm == current->active_mm)
	__flush_dcache_icache((void *) address);
	else
	flush_dcache_icache_page(page);
	set_bit(PG_arch_1, &page->flags);
	}
	}

	#ifdef CONFIG_PPC_STD_MMU
	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
	if (Hash != 0 && pte_young(pte)) {
	struct mm_struct *mm;
	pmd_t *pmd;

	mm = (address < TASK_SIZE)? vma->vm_mm: &init_mm;
	pmd = pmd_offset(pgd_offset(mm, address), address);
	if (!pmd_none(*pmd))
	add_hash_page(mm->context, address, pmd_val(*pmd));
	}
	#endif
	}

	/*
	* This is called by /dev/mem to know if a given address has to
	* be mapped non-cacheable or not
	*/
	int page_is_ram(unsigned long pfn)
	{
	return pfn < max_pfn;
	}

	pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
	unsigned long size, pgprot_t vma_prot)
	{
	if (ppc_md.phys_mem_access_prot)
	return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

	if (!page_is_ram(pfn))
	vma_prot = __pgprot(pgprot_val(vma_prot)
	\| _PAGE_GUARDED \| _PAGE_NO_CACHE);
	return vma_prot;
	}
	EXPORT_SYMBOL(phys_mem_access_prot);