1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
413 lines
9.9 KiB
C
413 lines
9.9 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/config.h>
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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 <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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#include <asm/map.h>
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#define TABLE_SIZE PTRS_PER_PTE * sizeof(pte_t))
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struct mmu_gather mmu_gathers[NR_CPUS];
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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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* 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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* 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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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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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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page = NODE_MEM_MAP(0);
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end = page + NODE_DATA(0)->node_spanned_pages;
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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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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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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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#define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
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#define PFN_UP(x) (PAGE_ALIGN(x) >> PAGE_SHIFT)
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#define PFN_SIZE(x) ((x) >> PAGE_SHIFT)
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#define PFN_RANGE(s,e) PFN_SIZE(PAGE_ALIGN((unsigned long)(e)) - \
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(((unsigned long)(s)) & PAGE_MASK))
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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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start_pfn = PFN_UP((unsigned long)&_end);
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bootmap_pfn = 0;
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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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start = PFN_UP(mi->bank->start);
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end = PFN_DOWN(mi->bank->size + mi->bank->start);
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if (start < start_pfn)
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start = start_pfn;
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if (end <= start)
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BUG();
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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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return bootmap_pfn;
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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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nodes_clear(node_online_map);
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node_set_online(0);
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np->bootmap_pages = 0;
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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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* 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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if (memend_pfn < np->end)
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memend_pfn = np->end;
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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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* 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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* 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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find_memend_and_nodes(mi, &node_info);
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bootmap_pfn = find_bootmap_pfn(mi, node_info.bootmap_pages);
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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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* 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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* 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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* 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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* 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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* 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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#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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/* 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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* 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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memcpy(&meminfo, mi, sizeof(meminfo));
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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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* 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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* initialise the zones in node 0 (archimedes have only 1 node)
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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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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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* 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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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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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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set_page_count(page, 1);
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free_page(addr);
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totalram_pages++;
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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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* 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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/* 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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high_memory = (void *)__va(meminfo.end);
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max_mapnr = virt_to_page(high_memory) - mem_map;
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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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num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;
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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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* 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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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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#ifdef CONFIG_BLK_DEV_INITRD
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static int keep_initrd;
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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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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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__setup("keepinitrd", keepinitrd_setup);
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#endif
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