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		f47807f359
		
	
	
	
	
		
			
			Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl> Cc: Ian Molton <spyro@f2s.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			404 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			404 lines
		
	
	
		
			9.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  linux/arch/arm26/mm/init.c
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|  *
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|  *  Copyright (C) 1995-2002 Russell King
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  */
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| #include <linux/signal.h>
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| #include <linux/sched.h>
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| #include <linux/kernel.h>
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| #include <linux/errno.h>
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| #include <linux/string.h>
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| #include <linux/types.h>
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| #include <linux/ptrace.h>
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| #include <linux/mman.h>
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| #include <linux/mm.h>
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| #include <linux/swap.h>
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| #include <linux/smp.h>
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| #include <linux/init.h>
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| #include <linux/initrd.h>
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| #include <linux/bootmem.h>
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| #include <linux/blkdev.h>
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| #include <linux/pfn.h>
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| 
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| #include <asm/segment.h>
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| #include <asm/mach-types.h>
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| #include <asm/dma.h>
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| #include <asm/hardware.h>
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| #include <asm/setup.h>
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| #include <asm/tlb.h>
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| 
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| #include <asm/map.h>
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| 
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| struct mmu_gather mmu_gathers[NR_CPUS];
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| 
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| extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
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| extern char _stext, _text, _etext, _end, __init_begin, __init_end;
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| #ifdef CONFIG_XIP_KERNEL
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| extern char _endtext, _sdata;
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| #endif
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| extern unsigned long phys_initrd_start;
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| extern unsigned long phys_initrd_size;
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| 
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| /*
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|  * The sole use of this is to pass memory configuration
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|  * data from paging_init to mem_init.
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|  */
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| static struct meminfo meminfo __initdata = { 0, };
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| 
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| /*
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|  * empty_zero_page is a special page that is used for
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|  * zero-initialized data and COW.
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|  */
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| struct page *empty_zero_page;
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| 
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| void show_mem(void)
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| {
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| 	int free = 0, total = 0, reserved = 0;
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| 	int shared = 0, cached = 0, slab = 0;
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| 	struct page *page, *end;
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| 
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| 	printk("Mem-info:\n");
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| 	show_free_areas();
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| 	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
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| 
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| 
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| 	page = NODE_MEM_MAP(0);
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| 	end  = page + NODE_DATA(0)->node_spanned_pages;
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| 
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| 	do {
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| 		total++;
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| 		if (PageReserved(page))
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| 			reserved++;
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| 		else if (PageSwapCache(page))
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| 			cached++;
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| 		else if (PageSlab(page))
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| 			slab++;
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| 		else if (!page_count(page))
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| 			free++;
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| 		else
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| 			shared += page_count(page) - 1;
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| 		page++;
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| 	} while (page < end);
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| 
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| 	printk("%d pages of RAM\n", total);
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| 	printk("%d free pages\n", free);
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| 	printk("%d reserved pages\n", reserved);
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| 	printk("%d slab pages\n", slab);
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| 	printk("%d pages shared\n", shared);
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| 	printk("%d pages swap cached\n", cached);
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| }
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| 
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| struct node_info {
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| 	unsigned int start;
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| 	unsigned int end;
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| 	int bootmap_pages;
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| };
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| 
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| /*
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|  * FIXME: We really want to avoid allocating the bootmap bitmap
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|  * over the top of the initrd.  Hopefully, this is located towards
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|  * the start of a bank, so if we allocate the bootmap bitmap at
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|  * the end, we won't clash.
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|  */
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| static unsigned int __init
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| find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
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| {
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| 	unsigned int start_pfn, bootmap_pfn;
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| 	unsigned int start, end;
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| 
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| 	start_pfn   = PFN_UP((unsigned long)&_end);
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| 	bootmap_pfn = 0;
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| 
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| 	/* ARM26 machines only have one node */
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| 	if (mi->bank->node != 0)
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| 		BUG();
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| 
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| 	start = PFN_UP(mi->bank->start);
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| 	end   = PFN_DOWN(mi->bank->size + mi->bank->start);
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| 
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| 	if (start < start_pfn)
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| 		start = start_pfn;
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| 
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| 	if (end <= start)
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| 		BUG();
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| 
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| 	if (end - start >= bootmap_pages) 
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| 		bootmap_pfn = start;
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| 	else
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| 		BUG();
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| 
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| 	return bootmap_pfn;
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| }
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| 
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| /*
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|  * Scan the memory info structure and pull out:
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|  *  - the end of memory
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|  *  - the number of nodes
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|  *  - the pfn range of each node
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|  *  - the number of bootmem bitmap pages
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|  */
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| static void __init
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| find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
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| {
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| 	unsigned int memend_pfn = 0;
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| 
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| 	nodes_clear(node_online_map);
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| 	node_set_online(0);
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| 
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| 	np->bootmap_pages = 0;
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| 
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| 	if (mi->bank->size == 0) {
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| 		BUG();
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| 	}
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| 
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| 	/*
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| 	 * Get the start and end pfns for this bank
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| 	 */
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| 	np->start = PFN_UP(mi->bank->start);
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| 	np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);
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| 
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| 	if (memend_pfn < np->end)
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| 		memend_pfn = np->end;
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| 
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| 	/*
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| 	 * Calculate the number of pages we require to
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| 	 * store the bootmem bitmaps.
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| 	 */
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| 	np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);
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| 
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| 	/*
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| 	 * This doesn't seem to be used by the Linux memory
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| 	 * manager any more.  If we can get rid of it, we
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| 	 * also get rid of some of the stuff above as well.
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| 	 */
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| 	max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
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| 	max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
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| 	mi->end = memend_pfn << PAGE_SHIFT;
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| 
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| }
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| 
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| /*
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|  * Initialise the bootmem allocator for all nodes.  This is called
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|  * early during the architecture specific initialisation.
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|  */
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| void __init bootmem_init(struct meminfo *mi)
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| {
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| 	struct node_info node_info;
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| 	unsigned int bootmap_pfn;
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| 	pg_data_t *pgdat = NODE_DATA(0);
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| 
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| 	find_memend_and_nodes(mi, &node_info);
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| 
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| 	bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);
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| 
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| 	/*
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| 	 * Note that node 0 must always have some pages.
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| 	 */
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| 	if (node_info.end == 0)
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| 		BUG();
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| 
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| 	/*
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| 	 * Initialise the bootmem allocator.
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| 	 */
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| 	init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);
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| 
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|  	/*
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| 	 * Register all available RAM in this node with the bootmem allocator. 
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| 	 */
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| 	free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);
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| 
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|         /*
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|          * Register the kernel text and data with bootmem.
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|          * Note: with XIP we dont register .text since
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|          * its in ROM.
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|          */
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| #ifdef CONFIG_XIP_KERNEL
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|         reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
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| #else
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|         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
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| #endif
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| 
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|         /*
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|          * And don't forget to reserve the allocator bitmap,
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|          * which will be freed later.
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|          */
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|         reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
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|                              node_info.bootmap_pages << PAGE_SHIFT);
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| 
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|         /*
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|          * These should likewise go elsewhere.  They pre-reserve
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|          * the screen memory region at the start of main system
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|          * memory. FIXME - screen RAM is not 512K!
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|          */
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|         reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);
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| 
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| #ifdef CONFIG_BLK_DEV_INITRD
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|         initrd_start = phys_initrd_start;
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|         initrd_end = initrd_start + phys_initrd_size;
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| 
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|         /* Achimedes machines only have one node, so initrd is in node 0 */
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| #ifdef CONFIG_XIP_KERNEL
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| 	/* Only reserve initrd space if it is in RAM */
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|         if(initrd_start && initrd_start < 0x03000000){
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| #else
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|         if(initrd_start){
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| #endif
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|                 reserve_bootmem_node(pgdat, __pa(initrd_start),
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|                                              initrd_end - initrd_start);
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| 	}
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| #endif   /* CONFIG_BLK_DEV_INITRD */
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| 
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| 
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| }
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| 
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| /*
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|  * paging_init() sets up the page tables, initialises the zone memory
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|  * maps, and sets up the zero page, bad page and bad page tables.
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|  */
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| void __init paging_init(struct meminfo *mi)
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| {
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| 	void *zero_page;
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| 	unsigned long zone_size[MAX_NR_ZONES];
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|         unsigned long zhole_size[MAX_NR_ZONES];
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|         struct bootmem_data *bdata;
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|         pg_data_t *pgdat;
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| 	int i;
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| 
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| 	memcpy(&meminfo, mi, sizeof(meminfo));
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| 
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| 	/*
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| 	 * allocate the zero page.  Note that we count on this going ok.
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| 	 */
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| 	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
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| 
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| 	/*
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| 	 * initialise the page tables.
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| 	 */
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| 	memtable_init(mi);
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| 	flush_tlb_all();
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| 
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| 	/*
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| 	 * initialise the zones in node 0 (archimedes have only 1 node)
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| 	 */
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| 
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| 	for (i = 0; i < MAX_NR_ZONES; i++) {
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| 		zone_size[i]  = 0;
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| 		zhole_size[i] = 0;
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| 	}
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| 
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| 	pgdat = NODE_DATA(0);
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| 	bdata = pgdat->bdata;
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| 	zone_size[0] = bdata->node_low_pfn -
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| 			(bdata->node_boot_start >> PAGE_SHIFT);
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| 	if (!zone_size[0])
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| 		BUG();
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| 	pgdat->node_mem_map = NULL;
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| 	free_area_init_node(0, pgdat, zone_size,
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| 			bdata->node_boot_start >> PAGE_SHIFT, zhole_size);
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| 
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| 	/*
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| 	 * finish off the bad pages once
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| 	 * the mem_map is initialised
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| 	 */
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| 	memzero(zero_page, PAGE_SIZE);
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| 	empty_zero_page = virt_to_page(zero_page);
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| }
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| 
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| static inline void free_area(unsigned long addr, unsigned long end, char *s)
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| {
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| 	unsigned int size = (end - addr) >> 10;
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| 
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| 	for (; addr < end; addr += PAGE_SIZE) {
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| 		struct page *page = virt_to_page(addr);
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| 		ClearPageReserved(page);
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| 		init_page_count(page);
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| 		free_page(addr);
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| 		totalram_pages++;
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| 	}
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| 
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| 	if (size && s)
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| 		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
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| }
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| 
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| /*
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|  * mem_init() marks the free areas in the mem_map and tells us how much
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|  * memory is free.  This is done after various parts of the system have
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|  * claimed their memory after the kernel image.
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|  */
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| void __init mem_init(void)
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| {
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| 	unsigned int codepages, datapages, initpages;
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| 	pg_data_t *pgdat = NODE_DATA(0);
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| 	extern int sysctl_overcommit_memory;
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| 
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| 
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| 	/* Note: data pages includes BSS */
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| #ifdef CONFIG_XIP_KERNEL
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| 	codepages = &_endtext - &_text;
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| 	datapages = &_end - &_sdata;
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| #else
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| 	codepages = &_etext - &_text;
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| 	datapages = &_end - &_etext;
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| #endif
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| 	initpages = &__init_end - &__init_begin;
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| 
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| 	high_memory = (void *)__va(meminfo.end);
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| 	max_mapnr   = virt_to_page(high_memory) - mem_map;
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| 
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| 	/* this will put all unused low memory onto the freelists */
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| 	if (pgdat->node_spanned_pages != 0)
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| 		totalram_pages += free_all_bootmem_node(pgdat);
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| 
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| 	num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
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| 
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| 	printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
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| 	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
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| 		"%dK data, %dK init)\n",
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| 		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
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| 		codepages >> 10, datapages >> 10, initpages >> 10);
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| 
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| 	/*
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| 	 * Turn on overcommit on tiny machines
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| 	 */
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| 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
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| 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
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| 		printk("Turning on overcommit\n");
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| 	}
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| }
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| 
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| void free_initmem(void){
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| #ifndef CONFIG_XIP_KERNEL
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| 	free_area((unsigned long)(&__init_begin),
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| 		  (unsigned long)(&__init_end),
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| 		  "init");
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| #endif
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| }
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| 
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| #ifdef CONFIG_BLK_DEV_INITRD
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| 
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| static int keep_initrd;
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| 
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| void free_initrd_mem(unsigned long start, unsigned long end)
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| {
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| #ifdef CONFIG_XIP_KERNEL
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| 	/* Only bin initrd if it is in RAM... */
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| 	if(!keep_initrd && start < 0x03000000)
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| #else
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| 	if (!keep_initrd)
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| #endif
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| 		free_area(start, end, "initrd");
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| }
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| 
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| static int __init keepinitrd_setup(char *__unused)
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| {
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| 	keep_initrd = 1;
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| 	return 1;
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| }
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| 
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| __setup("keepinitrd", keepinitrd_setup);
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| #endif
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