arch/powerpc/mm/mem.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
  *  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 <linux/suspend.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/lmb.h>
 #include <asm/sections.h>
 #include <asm/vdso.h>

 #include "mmu_decl.h"

 #ifndef CPU_FTR_COHERENT_ICACHE
 #define CPU_FTR_COHERENT_ICACHE	0	/* XXX for now */
 #define CPU_FTR_NOEXECUTE	0
 #endif

 int init_bootmem_done;
 int mem_init_done;
 unsigned long memory_limit;

 int page_is_ram(unsigned long pfn)
 {
 	unsigned long paddr = (pfn << PAGE_SHIFT);

 #ifndef CONFIG_PPC64	/* XXX for now */
 	return paddr < __pa(high_memory);
 #else
 	int i;
 	for (i=0; i < lmb.memory.cnt; i++) {
 		unsigned long base;

 		base = lmb.memory.region[i].base;

 		if ((paddr >= base) &&
 			(paddr < (base + lmb.memory.region[i].size))) {
 			return 1;
 		}
 	}

 	return 0;
 #endif
 }

 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);

 #ifdef CONFIG_MEMORY_HOTPLUG

 void online_page(struct page *page)
 {
 	ClearPageReserved(page);
 	init_page_count(page);
 	__free_page(page);
 	totalram_pages++;
 	num_physpages++;
 }

 #ifdef CONFIG_NUMA
 int memory_add_physaddr_to_nid(u64 start)
 {
 	return hot_add_scn_to_nid(start);
 }
 #endif

 int __devinit arch_add_memory(int nid, u64 start, u64 size)
 {
 	struct pglist_data *pgdata;
 	struct zone *zone;
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;

 	pgdata = NODE_DATA(nid);

 	start = (unsigned long)__va(start);
 	create_section_mapping(start, start + size);

 	/* this should work for most non-highmem platforms */
 	zone = pgdata->node_zones;

 	return __add_pages(zone, start_pfn, nr_pages);
 }

 #ifdef CONFIG_MEMORY_HOTREMOVE
 int remove_memory(u64 start, u64 size)
 {
 	unsigned long start_pfn, end_pfn;
 	int ret;

 	start_pfn = start >> PAGE_SHIFT;
 	end_pfn = start_pfn + (size >> PAGE_SHIFT);
 	ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
 	if (ret)
 		goto out;
 	/* Arch-specific calls go here - next patch */
 out:
 	return ret;
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */

 /*
  * walk_memory_resource() needs to make sure there is no holes in a given
  * memory range. On PPC64, since this range comes from /sysfs, the range
  * is guaranteed to be valid, non-overlapping and can not contain any
  * holes. By the time we get here (memory add or remove), /proc/device-tree
  * is updated and correct. Only reason we need to check against device-tree
  * would be if we allow user-land to specify a memory range through a
  * system call/ioctl etc. instead of doing offline/online through /sysfs.
  */
 int
 walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
 			int (*func)(unsigned long, unsigned long, void *))
 {
 	return  (*func)(start_pfn, nr_pages, arg);
 }

 #endif /* CONFIG_MEMORY_HOTPLUG */

 void show_mem(void)
 {
 	unsigned long total = 0, reserved = 0;
 	unsigned long shared = 0, cached = 0;
 	unsigned long highmem = 0;
 	struct page *page;
 	pg_data_t *pgdat;
 	unsigned long i;

 	printk("Mem-info:\n");
 	show_free_areas();
 	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 	for_each_online_pgdat(pgdat) {
 		unsigned long flags;
 		pgdat_resize_lock(pgdat, &flags);
 		for (i = 0; i < pgdat->node_spanned_pages; i++) {
 			if (!pfn_valid(pgdat->node_start_pfn + i))
 				continue;
 			page = pgdat_page_nr(pgdat, i);
 			total++;
 			if (PageHighMem(page))
 				highmem++;
 			if (PageReserved(page))
 				reserved++;
 			else if (PageSwapCache(page))
 				cached++;
 			else if (page_count(page))
 				shared += page_count(page) - 1;
 		}
 		pgdat_resize_unlock(pgdat, &flags);
 	}
 	printk("%ld pages of RAM\n", total);
 #ifdef CONFIG_HIGHMEM
 	printk("%ld pages of HIGHMEM\n", highmem);
 #endif
 	printk("%ld reserved pages\n", reserved);
 	printk("%ld pages shared\n", shared);
 	printk("%ld pages swap cached\n", cached);
 }

 /*
  * Initialize the bootmem system and give it all the memory we
  * have available.  If we are using highmem, we only put the
  * lowmem into the bootmem system.
  */
 #ifndef CONFIG_NEED_MULTIPLE_NODES
 void __init do_init_bootmem(void)
 {
 	unsigned long i;
 	unsigned long start, bootmap_pages;
 	unsigned long total_pages;
 	int boot_mapsize;

 	max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
 #ifdef CONFIG_HIGHMEM
 	total_pages = total_lowmem >> PAGE_SHIFT;
 #endif

 	/*
 	 * Find an area to use for the bootmem bitmap.  Calculate the size of
 	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
 	 * Add 1 additional page in case the address isn't page-aligned.
 	 */
 	bootmap_pages = bootmem_bootmap_pages(total_pages);

 	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);

 	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);

 	/* Add active regions with valid PFNs */
 	for (i = 0; i < lmb.memory.cnt; i++) {
 		unsigned long start_pfn, end_pfn;
 		start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
 		end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
 		add_active_range(0, start_pfn, end_pfn);
 	}

 	/* Add all physical memory to the bootmem map, mark each area
 	 * present.
 	 */
 #ifdef CONFIG_HIGHMEM
 	free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);

 	/* reserve the sections we're already using */
 	for (i = 0; i < lmb.reserved.cnt; i++) {
 		unsigned long addr = lmb.reserved.region[i].base +
 				     lmb_size_bytes(&lmb.reserved, i) - 1;
 		if (addr < total_lowmem)
 			reserve_bootmem(lmb.reserved.region[i].base,
 					lmb_size_bytes(&lmb.reserved, i),
 					BOOTMEM_DEFAULT);
 		else if (lmb.reserved.region[i].base < total_lowmem) {
 			unsigned long adjusted_size = total_lowmem -
 				      lmb.reserved.region[i].base;
 			reserve_bootmem(lmb.reserved.region[i].base,
 					adjusted_size, BOOTMEM_DEFAULT);
 		}
 	}
 #else
 	free_bootmem_with_active_regions(0, max_pfn);

 	/* reserve the sections we're already using */
 	for (i = 0; i < lmb.reserved.cnt; i++)
 		reserve_bootmem(lmb.reserved.region[i].base,
 				lmb_size_bytes(&lmb.reserved, i),
 				BOOTMEM_DEFAULT);

 #endif
 	/* XXX need to clip this if using highmem? */
 	sparse_memory_present_with_active_regions(0);

 	init_bootmem_done = 1;
 }

 /* mark pages that don't exist as nosave */
 static int __init mark_nonram_nosave(void)
 {
 	unsigned long lmb_next_region_start_pfn,
 		      lmb_region_max_pfn;
 	int i;

 	for (i = 0; i < lmb.memory.cnt - 1; i++) {
 		lmb_region_max_pfn =
 			(lmb.memory.region[i].base >> PAGE_SHIFT) +
 			(lmb.memory.region[i].size >> PAGE_SHIFT);
 		lmb_next_region_start_pfn =
 			lmb.memory.region[i+1].base >> PAGE_SHIFT;

 		if (lmb_region_max_pfn < lmb_next_region_start_pfn)
 			register_nosave_region(lmb_region_max_pfn,
 					       lmb_next_region_start_pfn);
 	}

 	return 0;
 }

 /*
  * paging_init() sets up the page tables - in fact we've already done this.
  */
 void __init paging_init(void)
 {
 	unsigned long total_ram = lmb_phys_mem_size();
 	unsigned long top_of_ram = lmb_end_of_DRAM();
 	unsigned long max_zone_pfns[MAX_NR_ZONES];

 #ifdef CONFIG_HIGHMEM
 	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
 	pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 			(PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
 	map_page(KMAP_FIX_BEGIN, 0, 0);	/* XXX gross */
 	kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
 			(KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
 			 KMAP_FIX_BEGIN);
 	kmap_prot = PAGE_KERNEL;
 #endif /* CONFIG_HIGHMEM */

 	printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
 	       top_of_ram, total_ram);
 	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 	       (top_of_ram - total_ram) >> 20);
 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 #ifdef CONFIG_HIGHMEM
 	max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
 	max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
 #else
 	max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
 #endif
 	free_area_init_nodes(max_zone_pfns);

 	mark_nonram_nosave();
 }
 #endif /* ! CONFIG_NEED_MULTIPLE_NODES */

 void __init mem_init(void)
 {
 #ifdef CONFIG_NEED_MULTIPLE_NODES
 	int nid;
 #endif
 	pg_data_t *pgdat;
 	unsigned long i;
 	struct page *page;
 	unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;

 	num_physpages = lmb.memory.size >> PAGE_SHIFT;
 	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);

 #ifdef CONFIG_NEED_MULTIPLE_NODES
         for_each_online_node(nid) {
 		if (NODE_DATA(nid)->node_spanned_pages != 0) {
 			printk("freeing bootmem node %d\n", nid);
 			totalram_pages +=
 				free_all_bootmem_node(NODE_DATA(nid));
 		}
 	}
 #else
 	max_mapnr = max_pfn;
 	totalram_pages += free_all_bootmem();
 #endif
 	for_each_online_pgdat(pgdat) {
 		for (i = 0; i < pgdat->node_spanned_pages; i++) {
 			if (!pfn_valid(pgdat->node_start_pfn + i))
 				continue;
 			page = pgdat_page_nr(pgdat, i);
 			if (PageReserved(page))
 				reservedpages++;
 		}
 	}

 	codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
 	datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
 	initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
 	bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;

 #ifdef CONFIG_HIGHMEM
 	{
 		unsigned long pfn, highmem_mapnr;

 		highmem_mapnr = total_lowmem >> PAGE_SHIFT;
 		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 			struct page *page = pfn_to_page(pfn);
 			if (lmb_is_reserved(pfn << PAGE_SHIFT))
 				continue;
 			ClearPageReserved(page);
 			init_page_count(page);
 			__free_page(page);
 			totalhigh_pages++;
 			reservedpages--;
 		}
 		totalram_pages += totalhigh_pages;
 		printk(KERN_DEBUG "High memory: %luk\n",
 		       totalhigh_pages << (PAGE_SHIFT-10));
 	}
 #endif /* CONFIG_HIGHMEM */

 	printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
 	       "%luk reserved, %luk data, %luk bss, %luk init)\n",
 		(unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
 		num_physpages << (PAGE_SHIFT-10),
 		codesize >> 10,
 		reservedpages << (PAGE_SHIFT-10),
 		datasize >> 10,
 		bsssize >> 10,
 		initsize >> 10);

 	mem_init_done = 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)
 {
 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 		return;
 	/* avoid an atomic op if possible */
 	if (test_bit(PG_arch_1, &page->flags))
 		clear_bit(PG_arch_1, &page->flags);
 }
 EXPORT_SYMBOL(flush_dcache_page);

 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) || defined(CONFIG_PPC64)
 	/* 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);

 	/*
 	 * We shouldnt have to do this, but some versions of glibc
 	 * require it (ld.so assumes zero filled pages are icache clean)
 	 * - Anton
 	 */
 	flush_dcache_page(pg);
 }
 EXPORT_SYMBOL(clear_user_page);

 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 		    struct page *pg)
 {
 	copy_page(vto, vfrom);

 	/*
 	 * We should be able to use the following optimisation, however
 	 * there are two problems.
 	 * Firstly a bug in some versions of binutils meant PLT sections
 	 * were not marked executable.
 	 * Secondly the first word in the GOT section is blrl, used
 	 * to establish the GOT address. Until recently the GOT was
 	 * not marked executable.
 	 * - Anton
 	 */
 #if 0
 	if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 		return;
 #endif

 	flush_dcache_page(pg);
 }

 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);
 }
 EXPORT_SYMBOL(flush_icache_user_range);

 /*
  * 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.
  *
  * This must always be called with the pte lock held.
  */
 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
 		      pte_t pte)
 {
 #ifdef CONFIG_PPC_STD_MMU
 	unsigned long access = 0, trap;
 #endif
 	unsigned long pfn = pte_pfn(pte);

 	/* handle i-cache coherency */
 	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 	    !cpu_has_feature(CPU_FTR_NOEXECUTE) &&
 	    pfn_valid(pfn)) {
 		struct page *page = pfn_to_page(pfn);
 #ifdef CONFIG_8xx
 		/* On 8xx, cache control instructions (particularly
 		 * "dcbst" from flush_dcache_icache) fault as write
 		 * operation if there is an unpopulated TLB entry
 		 * for the address in question. To workaround that,
 		 * we invalidate the TLB here, thus avoiding dcbst
 		 * misbehaviour.
 		 */
 		_tlbie(address, 0 /* 8xx doesn't care about PID */);
 #endif
 		/* The _PAGE_USER test should really be _PAGE_EXEC, but
 		 * older glibc versions execute some code from no-exec
 		 * pages, which for now we are supporting.  If exec-only
 		 * pages are ever implemented, this will have to change.
 		 */
 		if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER)
 		    && !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 (!pte_young(pte) || address >= TASK_SIZE)
 		return;

 	/* We try to figure out if we are coming from an instruction
 	 * access fault and pass that down to __hash_page so we avoid
 	 * double-faulting on execution of fresh text. We have to test
 	 * for regs NULL since init will get here first thing at boot
 	 *
 	 * We also avoid filling the hash if not coming from a fault
 	 */
 	if (current->thread.regs == NULL)
 		return;
 	trap = TRAP(current->thread.regs);
 	if (trap == 0x400)
 		access |= _PAGE_EXEC;
 	else if (trap != 0x300)
 		return;
 	hash_preload(vma->vm_mm, address, access, trap);
 #endif /* CONFIG_PPC_STD_MMU */
 }
	/*
	* 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 <linux/suspend.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/lmb.h>
	#include <asm/sections.h>
	#include <asm/vdso.h>

	#include "mmu_decl.h"

	#ifndef CPU_FTR_COHERENT_ICACHE
	#define CPU_FTR_COHERENT_ICACHE 0 /* XXX for now */
	#define CPU_FTR_NOEXECUTE 0
	#endif

	int init_bootmem_done;
	int mem_init_done;
	unsigned long memory_limit;

	int page_is_ram(unsigned long pfn)
	{
	unsigned long paddr = (pfn << PAGE_SHIFT);

	#ifndef CONFIG_PPC64 /* XXX for now */
	return paddr < __pa(high_memory);
	#else
	int i;
	for (i=0; i < lmb.memory.cnt; i++) {
	unsigned long base;

	base = lmb.memory.region[i].base;

	if ((paddr >= base) &&
	(paddr < (base + lmb.memory.region[i].size))) {
	return 1;
	}
	}

	return 0;
	#endif
	}

	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);

	#ifdef CONFIG_MEMORY_HOTPLUG

	void online_page(struct page *page)
	{
	ClearPageReserved(page);
	init_page_count(page);
	__free_page(page);
	totalram_pages++;
	num_physpages++;
	}

	#ifdef CONFIG_NUMA
	int memory_add_physaddr_to_nid(u64 start)
	{
	return hot_add_scn_to_nid(start);
	}
	#endif

	int __devinit arch_add_memory(int nid, u64 start, u64 size)
	{
	struct pglist_data *pgdata;
	struct zone *zone;
	unsigned long start_pfn = start >> PAGE_SHIFT;
	unsigned long nr_pages = size >> PAGE_SHIFT;

	pgdata = NODE_DATA(nid);

	start = (unsigned long)__va(start);
	create_section_mapping(start, start + size);

	/* this should work for most non-highmem platforms */
	zone = pgdata->node_zones;

	return __add_pages(zone, start_pfn, nr_pages);
	}

	#ifdef CONFIG_MEMORY_HOTREMOVE
	int remove_memory(u64 start, u64 size)
	{
	unsigned long start_pfn, end_pfn;
	int ret;

	start_pfn = start >> PAGE_SHIFT;
	end_pfn = start_pfn + (size >> PAGE_SHIFT);
	ret = offline_pages(start_pfn, end_pfn, 120 * HZ);
	if (ret)
	goto out;
	/* Arch-specific calls go here - next patch */
	out:
	return ret;
	}
	#endif /* CONFIG_MEMORY_HOTREMOVE */

	/*
	* walk_memory_resource() needs to make sure there is no holes in a given
	* memory range. On PPC64, since this range comes from /sysfs, the range
	* is guaranteed to be valid, non-overlapping and can not contain any
	* holes. By the time we get here (memory add or remove), /proc/device-tree
	* is updated and correct. Only reason we need to check against device-tree
	* would be if we allow user-land to specify a memory range through a
	* system call/ioctl etc. instead of doing offline/online through /sysfs.
	*/
	int
	walk_memory_resource(unsigned long start_pfn, unsigned long nr_pages, void *arg,
	int (func)(unsigned long, unsigned long, void ))
	{
	return (*func)(start_pfn, nr_pages, arg);
	}

	#endif /* CONFIG_MEMORY_HOTPLUG */

	void show_mem(void)
	{
	unsigned long total = 0, reserved = 0;
	unsigned long shared = 0, cached = 0;
	unsigned long highmem = 0;
	struct page *page;
	pg_data_t *pgdat;
	unsigned long i;

	printk("Mem-info:\n");
	show_free_areas();
	printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
	for_each_online_pgdat(pgdat) {
	unsigned long flags;
	pgdat_resize_lock(pgdat, &flags);
	for (i = 0; i < pgdat->node_spanned_pages; i++) {
	if (!pfn_valid(pgdat->node_start_pfn + i))
	continue;
	page = pgdat_page_nr(pgdat, i);
	total++;
	if (PageHighMem(page))
	highmem++;
	if (PageReserved(page))
	reserved++;
	else if (PageSwapCache(page))
	cached++;
	else if (page_count(page))
	shared += page_count(page) - 1;
	}
	pgdat_resize_unlock(pgdat, &flags);
	}
	printk("%ld pages of RAM\n", total);
	#ifdef CONFIG_HIGHMEM
	printk("%ld pages of HIGHMEM\n", highmem);
	#endif
	printk("%ld reserved pages\n", reserved);
	printk("%ld pages shared\n", shared);
	printk("%ld pages swap cached\n", cached);
	}

	/*
	* Initialize the bootmem system and give it all the memory we
	* have available. If we are using highmem, we only put the
	* lowmem into the bootmem system.
	*/
	#ifndef CONFIG_NEED_MULTIPLE_NODES
	void __init do_init_bootmem(void)
	{
	unsigned long i;
	unsigned long start, bootmap_pages;
	unsigned long total_pages;
	int boot_mapsize;

	max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
	#ifdef CONFIG_HIGHMEM
	total_pages = total_lowmem >> PAGE_SHIFT;
	#endif

	/*
	* Find an area to use for the bootmem bitmap. Calculate the size of
	* bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
	* Add 1 additional page in case the address isn't page-aligned.
	*/
	bootmap_pages = bootmem_bootmap_pages(total_pages);

	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);

	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);

	/* Add active regions with valid PFNs */
	for (i = 0; i < lmb.memory.cnt; i++) {
	unsigned long start_pfn, end_pfn;
	start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
	end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
	add_active_range(0, start_pfn, end_pfn);
	}

	/* Add all physical memory to the bootmem map, mark each area
	* present.
	*/
	#ifdef CONFIG_HIGHMEM
	free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);

	/* reserve the sections we're already using */
	for (i = 0; i < lmb.reserved.cnt; i++) {
	unsigned long addr = lmb.reserved.region[i].base +
	lmb_size_bytes(&lmb.reserved, i) - 1;
	if (addr < total_lowmem)
	reserve_bootmem(lmb.reserved.region[i].base,
	lmb_size_bytes(&lmb.reserved, i),
	BOOTMEM_DEFAULT);
	else if (lmb.reserved.region[i].base < total_lowmem) {
	unsigned long adjusted_size = total_lowmem -
	lmb.reserved.region[i].base;
	reserve_bootmem(lmb.reserved.region[i].base,
	adjusted_size, BOOTMEM_DEFAULT);
	}
	}
	#else
	free_bootmem_with_active_regions(0, max_pfn);

	/* reserve the sections we're already using */
	for (i = 0; i < lmb.reserved.cnt; i++)
	reserve_bootmem(lmb.reserved.region[i].base,
	lmb_size_bytes(&lmb.reserved, i),
	BOOTMEM_DEFAULT);

	#endif
	/* XXX need to clip this if using highmem? */
	sparse_memory_present_with_active_regions(0);

	init_bootmem_done = 1;
	}

	/* mark pages that don't exist as nosave */
	static int __init mark_nonram_nosave(void)
	{
	unsigned long lmb_next_region_start_pfn,
	lmb_region_max_pfn;
	int i;

	for (i = 0; i < lmb.memory.cnt - 1; i++) {
	lmb_region_max_pfn =
	(lmb.memory.region[i].base >> PAGE_SHIFT) +
	(lmb.memory.region[i].size >> PAGE_SHIFT);
	lmb_next_region_start_pfn =
	lmb.memory.region[i+1].base >> PAGE_SHIFT;

	if (lmb_region_max_pfn < lmb_next_region_start_pfn)
	register_nosave_region(lmb_region_max_pfn,
	lmb_next_region_start_pfn);
	}

	return 0;
	}

	/*
	* paging_init() sets up the page tables - in fact we've already done this.
	*/
	void __init paging_init(void)
	{
	unsigned long total_ram = lmb_phys_mem_size();
	unsigned long top_of_ram = lmb_end_of_DRAM();
	unsigned long max_zone_pfns[MAX_NR_ZONES];

	#ifdef CONFIG_HIGHMEM
	map_page(PKMAP_BASE, 0, 0); /* XXX gross */
	pkmap_page_table = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
	(PKMAP_BASE), PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
	map_page(KMAP_FIX_BEGIN, 0, 0); /* XXX gross */
	kmap_pte = pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k
	(KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN),
	KMAP_FIX_BEGIN);
	kmap_prot = PAGE_KERNEL;
	#endif /* CONFIG_HIGHMEM */

	printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
	top_of_ram, total_ram);
	printk(KERN_DEBUG "Memory hole size: %ldMB\n",
	(top_of_ram - total_ram) >> 20);
	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
	#ifdef CONFIG_HIGHMEM
	max_zone_pfns[ZONE_DMA] = total_lowmem >> PAGE_SHIFT;
	max_zone_pfns[ZONE_HIGHMEM] = top_of_ram >> PAGE_SHIFT;
	#else
	max_zone_pfns[ZONE_DMA] = top_of_ram >> PAGE_SHIFT;
	#endif
	free_area_init_nodes(max_zone_pfns);

	mark_nonram_nosave();
	}
	#endif /* ! CONFIG_NEED_MULTIPLE_NODES */

	void __init mem_init(void)
	{
	#ifdef CONFIG_NEED_MULTIPLE_NODES
	int nid;
	#endif
	pg_data_t *pgdat;
	unsigned long i;
	struct page *page;
	unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;

	num_physpages = lmb.memory.size >> PAGE_SHIFT;
	high_memory = (void ) __va(max_low_pfn PAGE_SIZE);

	#ifdef CONFIG_NEED_MULTIPLE_NODES
	for_each_online_node(nid) {
	if (NODE_DATA(nid)->node_spanned_pages != 0) {
	printk("freeing bootmem node %d\n", nid);
	totalram_pages +=
	free_all_bootmem_node(NODE_DATA(nid));
	}
	}
	#else
	max_mapnr = max_pfn;
	totalram_pages += free_all_bootmem();
	#endif
	for_each_online_pgdat(pgdat) {
	for (i = 0; i < pgdat->node_spanned_pages; i++) {
	if (!pfn_valid(pgdat->node_start_pfn + i))
	continue;
	page = pgdat_page_nr(pgdat, i);
	if (PageReserved(page))
	reservedpages++;
	}
	}

	codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
	datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
	initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
	bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;

	#ifdef CONFIG_HIGHMEM
	{
	unsigned long pfn, highmem_mapnr;

	highmem_mapnr = total_lowmem >> PAGE_SHIFT;
	for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
	struct page *page = pfn_to_page(pfn);
	if (lmb_is_reserved(pfn << PAGE_SHIFT))
	continue;
	ClearPageReserved(page);
	init_page_count(page);
	__free_page(page);
	totalhigh_pages++;
	reservedpages--;
	}
	totalram_pages += totalhigh_pages;
	printk(KERN_DEBUG "High memory: %luk\n",
	totalhigh_pages << (PAGE_SHIFT-10));
	}
	#endif /* CONFIG_HIGHMEM */

	printk(KERN_INFO "Memory: %luk/%luk available (%luk kernel code, "
	"%luk reserved, %luk data, %luk bss, %luk init)\n",
	(unsigned long)nr_free_pages() << (PAGE_SHIFT-10),
	num_physpages << (PAGE_SHIFT-10),
	codesize >> 10,
	reservedpages << (PAGE_SHIFT-10),
	datasize >> 10,
	bsssize >> 10,
	initsize >> 10);

	mem_init_done = 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)
	{
	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
	return;
	/* avoid an atomic op if possible */
	if (test_bit(PG_arch_1, &page->flags))
	clear_bit(PG_arch_1, &page->flags);
	}
	EXPORT_SYMBOL(flush_dcache_page);

	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) \|\| defined(CONFIG_PPC64)
	/* 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);

	/*
	* We shouldnt have to do this, but some versions of glibc
	* require it (ld.so assumes zero filled pages are icache clean)
	* - Anton
	*/
	flush_dcache_page(pg);
	}
	EXPORT_SYMBOL(clear_user_page);

	void copy_user_page(void vto, void vfrom, unsigned long vaddr,
	struct page *pg)
	{
	copy_page(vto, vfrom);

	/*
	* We should be able to use the following optimisation, however
	* there are two problems.
	* Firstly a bug in some versions of binutils meant PLT sections
	* were not marked executable.
	* Secondly the first word in the GOT section is blrl, used
	* to establish the GOT address. Until recently the GOT was
	* not marked executable.
	* - Anton
	*/
	#if 0
	if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
	return;
	#endif

	flush_dcache_page(pg);
	}

	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);
	}
	EXPORT_SYMBOL(flush_icache_user_range);

	/*
	* 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.
	*
	* This must always be called with the pte lock held.
	*/
	void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
	pte_t pte)
	{
	#ifdef CONFIG_PPC_STD_MMU
	unsigned long access = 0, trap;
	#endif
	unsigned long pfn = pte_pfn(pte);

	/* handle i-cache coherency */
	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
	!cpu_has_feature(CPU_FTR_NOEXECUTE) &&
	pfn_valid(pfn)) {
	struct page *page = pfn_to_page(pfn);
	#ifdef CONFIG_8xx
	/* On 8xx, cache control instructions (particularly
	* "dcbst" from flush_dcache_icache) fault as write
	* operation if there is an unpopulated TLB entry
	* for the address in question. To workaround that,
	* we invalidate the TLB here, thus avoiding dcbst
	* misbehaviour.
	*/
	_tlbie(address, 0 /* 8xx doesn't care about PID */);
	#endif
	/* The _PAGE_USER test should really be _PAGE_EXEC, but
	* older glibc versions execute some code from no-exec
	* pages, which for now we are supporting. If exec-only
	* pages are ever implemented, this will have to change.
	*/
	if (!PageReserved(page) && (pte_val(pte) & _PAGE_USER)
	&& !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 (!pte_young(pte) \|\| address >= TASK_SIZE)
	return;

	/* We try to figure out if we are coming from an instruction
	* access fault and pass that down to __hash_page so we avoid
	* double-faulting on execution of fresh text. We have to test
	* for regs NULL since init will get here first thing at boot
	*
	* We also avoid filling the hash if not coming from a fault
	*/
	if (current->thread.regs == NULL)
	return;
	trap = TRAP(current->thread.regs);
	if (trap == 0x400)
	access \|= _PAGE_EXEC;
	else if (trap != 0x300)
	return;
	hash_preload(vma->vm_mm, address, access, trap);
	#endif /* CONFIG_PPC_STD_MMU */
	}