arch/arm26/mm/init.c - linux - Git at Google

 /*
  *  linux/arch/arm26/mm/init.c
  *
  *  Copyright (C) 1995-2002 Russell King
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/ptrace.h>
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/smp.h>
 #include <linux/init.h>
 #include <linux/initrd.h>
 #include <linux/bootmem.h>
 #include <linux/blkdev.h>
 #include <linux/pfn.h>

 #include <asm/segment.h>
 #include <asm/mach-types.h>
 #include <asm/dma.h>
 #include <asm/hardware.h>
 #include <asm/setup.h>
 #include <asm/tlb.h>

 #include <asm/map.h>

 struct mmu_gather mmu_gathers[NR_CPUS];

 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern char _stext, _text, _etext, _end, __init_begin, __init_end;
 #ifdef CONFIG_XIP_KERNEL
 extern char _endtext, _sdata;
 #endif
 extern unsigned long phys_initrd_start;
 extern unsigned long phys_initrd_size;

 /*
  * The sole use of this is to pass memory configuration
  * data from paging_init to mem_init.
  */
 static struct meminfo meminfo __initdata = { 0, };

 /*
  * empty_zero_page is a special page that is used for
  * zero-initialized data and COW.
  */
 struct page *empty_zero_page;

 void show_mem(void)
 {
 	int free = 0, total = 0, reserved = 0;
 	int shared = 0, cached = 0, slab = 0;
 	struct page *page, *end;

 	printk("Mem-info:\n");
 	show_free_areas();
 	printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));


 	page = NODE_MEM_MAP(0);
 	end  = page + NODE_DATA(0)->node_spanned_pages;

 	do {
 		total++;
 		if (PageReserved(page))
 			reserved++;
 		else if (PageSwapCache(page))
 			cached++;
 		else if (PageSlab(page))
 			slab++;
 		else if (!page_count(page))
 			free++;
 		else
 			shared += page_count(page) - 1;
 		page++;
 	} while (page < end);

 	printk("%d pages of RAM\n", total);
 	printk("%d free pages\n", free);
 	printk("%d reserved pages\n", reserved);
 	printk("%d slab pages\n", slab);
 	printk("%d pages shared\n", shared);
 	printk("%d pages swap cached\n", cached);
 }

 struct node_info {
 	unsigned int start;
 	unsigned int end;
 	int bootmap_pages;
 };

 /*
  * FIXME: We really want to avoid allocating the bootmap bitmap
  * over the top of the initrd.  Hopefully, this is located towards
  * the start of a bank, so if we allocate the bootmap bitmap at
  * the end, we won't clash.
  */
 static unsigned int __init
 find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
 {
 	unsigned int start_pfn, bootmap_pfn;
 	unsigned int start, end;

 	start_pfn   = PFN_UP((unsigned long)&_end);
 	bootmap_pfn = 0;

 	/* ARM26 machines only have one node */
 	if (mi->bank->node != 0)
 		BUG();

 	start = PFN_UP(mi->bank->start);
 	end   = PFN_DOWN(mi->bank->size + mi->bank->start);

 	if (start < start_pfn)
 		start = start_pfn;

 	if (end <= start)
 		BUG();

 	if (end - start >= bootmap_pages)
 		bootmap_pfn = start;
 	else
 		BUG();

 	return bootmap_pfn;
 }

 /*
  * Scan the memory info structure and pull out:
  *  - the end of memory
  *  - the number of nodes
  *  - the pfn range of each node
  *  - the number of bootmem bitmap pages
  */
 static void __init
 find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 {
 	unsigned int memend_pfn = 0;

 	nodes_clear(node_online_map);
 	node_set_online(0);

 	np->bootmap_pages = 0;

 	if (mi->bank->size == 0) {
 		BUG();
 	}

 	/*
 	 * Get the start and end pfns for this bank
 	 */
 	np->start = PFN_UP(mi->bank->start);
 	np->end   = PFN_DOWN(mi->bank->start + mi->bank->size);

 	if (memend_pfn < np->end)
 		memend_pfn = np->end;

 	/*
 	 * Calculate the number of pages we require to
 	 * store the bootmem bitmaps.
 	 */
 	np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);

 	/*
 	 * This doesn't seem to be used by the Linux memory
 	 * manager any more.  If we can get rid of it, we
 	 * also get rid of some of the stuff above as well.
 	 */
 	max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 	max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
 	mi->end = memend_pfn << PAGE_SHIFT;

 }

 /*
  * Initialise the bootmem allocator for all nodes.  This is called
  * early during the architecture specific initialisation.
  */
 void __init bootmem_init(struct meminfo *mi)
 {
 	struct node_info node_info;
 	unsigned int bootmap_pfn;
 	pg_data_t *pgdat = NODE_DATA(0);

 	find_memend_and_nodes(mi, &node_info);

 	bootmap_pfn   = find_bootmap_pfn(mi, node_info.bootmap_pages);

 	/*
 	 * Note that node 0 must always have some pages.
 	 */
 	if (node_info.end == 0)
 		BUG();

 	/*
 	 * Initialise the bootmem allocator.
 	 */
 	init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);

  	/*
 	 * Register all available RAM in this node with the bootmem allocator.
 	 */
 	free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);

         /*
          * Register the kernel text and data with bootmem.
          * Note: with XIP we dont register .text since
          * its in ROM.
          */
 #ifdef CONFIG_XIP_KERNEL
         reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
 #else
         reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
 #endif

         /*
          * And don't forget to reserve the allocator bitmap,
          * which will be freed later.
          */
         reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
                              node_info.bootmap_pages << PAGE_SHIFT);

         /*
          * These should likewise go elsewhere.  They pre-reserve
          * the screen memory region at the start of main system
          * memory. FIXME - screen RAM is not 512K!
          */
         reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);

 #ifdef CONFIG_BLK_DEV_INITRD
         initrd_start = phys_initrd_start;
         initrd_end = initrd_start + phys_initrd_size;

         /* Achimedes machines only have one node, so initrd is in node 0 */
 #ifdef CONFIG_XIP_KERNEL
 	/* Only reserve initrd space if it is in RAM */
         if(initrd_start && initrd_start < 0x03000000){
 #else
         if(initrd_start){
 #endif
                 reserve_bootmem_node(pgdat, __pa(initrd_start),
                                              initrd_end - initrd_start);
 	}
 #endif   /* CONFIG_BLK_DEV_INITRD */


 }

 /*
  * paging_init() sets up the page tables, initialises the zone memory
  * maps, and sets up the zero page, bad page and bad page tables.
  */
 void __init paging_init(struct meminfo *mi)
 {
 	void *zero_page;
 	unsigned long zone_size[MAX_NR_ZONES];
         unsigned long zhole_size[MAX_NR_ZONES];
         struct bootmem_data *bdata;
         pg_data_t *pgdat;
 	int i;

 	memcpy(&meminfo, mi, sizeof(meminfo));

 	/*
 	 * allocate the zero page.  Note that we count on this going ok.
 	 */
 	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

 	/*
 	 * initialise the page tables.
 	 */
 	memtable_init(mi);
 	flush_tlb_all();

 	/*
 	 * initialise the zones in node 0 (archimedes have only 1 node)
 	 */

 	for (i = 0; i < MAX_NR_ZONES; i++) {
 		zone_size[i]  = 0;
 		zhole_size[i] = 0;
 	}

 	pgdat = NODE_DATA(0);
 	bdata = pgdat->bdata;
 	zone_size[0] = bdata->node_low_pfn -
 			(bdata->node_boot_start >> PAGE_SHIFT);
 	if (!zone_size[0])
 		BUG();
 	pgdat->node_mem_map = NULL;
 	free_area_init_node(0, pgdat, zone_size,
 			bdata->node_boot_start >> PAGE_SHIFT, zhole_size);

 	/*
 	 * finish off the bad pages once
 	 * the mem_map is initialised
 	 */
 	memzero(zero_page, PAGE_SIZE);
 	empty_zero_page = virt_to_page(zero_page);
 }

 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 {
 	unsigned int size = (end - addr) >> 10;

 	for (; addr < end; addr += PAGE_SIZE) {
 		struct page *page = virt_to_page(addr);
 		ClearPageReserved(page);
 		init_page_count(page);
 		free_page(addr);
 		totalram_pages++;
 	}

 	if (size && s)
 		printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
 }

 /*
  * mem_init() marks the free areas in the mem_map and tells us how much
  * memory is free.  This is done after various parts of the system have
  * claimed their memory after the kernel image.
  */
 void __init mem_init(void)
 {
 	unsigned int codepages, datapages, initpages;
 	pg_data_t *pgdat = NODE_DATA(0);
 	extern int sysctl_overcommit_memory;


 	/* Note: data pages includes BSS */
 #ifdef CONFIG_XIP_KERNEL
 	codepages = &_endtext - &_text;
 	datapages = &_end - &_sdata;
 #else
 	codepages = &_etext - &_text;
 	datapages = &_end - &_etext;
 #endif
 	initpages = &__init_end - &__init_begin;

 	high_memory = (void *)__va(meminfo.end);
 	max_mapnr   = virt_to_page(high_memory) - mem_map;

 	/* this will put all unused low memory onto the freelists */
 	if (pgdat->node_spanned_pages != 0)
 		totalram_pages += free_all_bootmem_node(pgdat);

 	num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;

 	printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
 	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
 		"%dK data, %dK init)\n",
 		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 		codepages >> 10, datapages >> 10, initpages >> 10);

 	/*
 	 * Turn on overcommit on tiny machines
 	 */
 	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
 		sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 		printk("Turning on overcommit\n");
 	}
 }

 void free_initmem(void){
 #ifndef CONFIG_XIP_KERNEL
 	free_area((unsigned long)(&__init_begin),
 		  (unsigned long)(&__init_end),
 		  "init");
 #endif
 }

 #ifdef CONFIG_BLK_DEV_INITRD

 static int keep_initrd;

 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 #ifdef CONFIG_XIP_KERNEL
 	/* Only bin initrd if it is in RAM... */
 	if(!keep_initrd && start < 0x03000000)
 #else
 	if (!keep_initrd)
 #endif
 		free_area(start, end, "initrd");
 }

 static int __init keepinitrd_setup(char *__unused)
 {
 	keep_initrd = 1;
 	return 1;
 }

 __setup("keepinitrd", keepinitrd_setup);
 #endif
	/*
	* linux/arch/arm26/mm/init.c
	*
	* Copyright (C) 1995-2002 Russell King
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#include <linux/signal.h>
	#include <linux/sched.h>
	#include <linux/kernel.h>
	#include <linux/errno.h>
	#include <linux/string.h>
	#include <linux/types.h>
	#include <linux/ptrace.h>
	#include <linux/mman.h>
	#include <linux/mm.h>
	#include <linux/swap.h>
	#include <linux/smp.h>
	#include <linux/init.h>
	#include <linux/initrd.h>
	#include <linux/bootmem.h>
	#include <linux/blkdev.h>
	#include <linux/pfn.h>

	#include <asm/segment.h>
	#include <asm/mach-types.h>
	#include <asm/dma.h>
	#include <asm/hardware.h>
	#include <asm/setup.h>
	#include <asm/tlb.h>

	#include <asm/map.h>

	struct mmu_gather mmu_gathers[NR_CPUS];

	extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
	extern char _stext, _text, _etext, _end, __init_begin, __init_end;
	#ifdef CONFIG_XIP_KERNEL
	extern char _endtext, _sdata;
	#endif
	extern unsigned long phys_initrd_start;
	extern unsigned long phys_initrd_size;

	/*
	* The sole use of this is to pass memory configuration
	* data from paging_init to mem_init.
	*/
	static struct meminfo meminfo __initdata = { 0, };

	/*
	* empty_zero_page is a special page that is used for
	* zero-initialized data and COW.
	*/
	struct page *empty_zero_page;

	void show_mem(void)
	{
	int free = 0, total = 0, reserved = 0;
	int shared = 0, cached = 0, slab = 0;
	struct page page, end;

	printk("Mem-info:\n");
	show_free_areas();
	printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));


	page = NODE_MEM_MAP(0);
	end = page + NODE_DATA(0)->node_spanned_pages;

	do {
	total++;
	if (PageReserved(page))
	reserved++;
	else if (PageSwapCache(page))
	cached++;
	else if (PageSlab(page))
	slab++;
	else if (!page_count(page))
	free++;
	else
	shared += page_count(page) - 1;
	page++;
	} while (page < end);

	printk("%d pages of RAM\n", total);
	printk("%d free pages\n", free);
	printk("%d reserved pages\n", reserved);
	printk("%d slab pages\n", slab);
	printk("%d pages shared\n", shared);
	printk("%d pages swap cached\n", cached);
	}

	struct node_info {
	unsigned int start;
	unsigned int end;
	int bootmap_pages;
	};

	/*
	* FIXME: We really want to avoid allocating the bootmap bitmap
	* over the top of the initrd. Hopefully, this is located towards
	* the start of a bank, so if we allocate the bootmap bitmap at
	* the end, we won't clash.
	*/
	static unsigned int __init
	find_bootmap_pfn(struct meminfo *mi, unsigned int bootmap_pages)
	{
	unsigned int start_pfn, bootmap_pfn;
	unsigned int start, end;

	start_pfn = PFN_UP((unsigned long)&_end);
	bootmap_pfn = 0;

	/* ARM26 machines only have one node */
	if (mi->bank->node != 0)
	BUG();

	start = PFN_UP(mi->bank->start);
	end = PFN_DOWN(mi->bank->size + mi->bank->start);

	if (start < start_pfn)
	start = start_pfn;

	if (end <= start)
	BUG();

	if (end - start >= bootmap_pages)
	bootmap_pfn = start;
	else
	BUG();

	return bootmap_pfn;
	}

	/*
	* Scan the memory info structure and pull out:
	* - the end of memory
	* - the number of nodes
	* - the pfn range of each node
	* - the number of bootmem bitmap pages
	*/
	static void __init
	find_memend_and_nodes(struct meminfo mi, struct node_info np)
	{
	unsigned int memend_pfn = 0;

	nodes_clear(node_online_map);
	node_set_online(0);

	np->bootmap_pages = 0;

	if (mi->bank->size == 0) {
	BUG();
	}

	/*
	* Get the start and end pfns for this bank
	*/
	np->start = PFN_UP(mi->bank->start);
	np->end = PFN_DOWN(mi->bank->start + mi->bank->size);

	if (memend_pfn < np->end)
	memend_pfn = np->end;

	/*
	* Calculate the number of pages we require to
	* store the bootmem bitmaps.
	*/
	np->bootmap_pages = bootmem_bootmap_pages(np->end - np->start);

	/*
	* This doesn't seem to be used by the Linux memory
	* manager any more. If we can get rid of it, we
	* also get rid of some of the stuff above as well.
	*/
	max_low_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
	max_pfn = memend_pfn - PFN_DOWN(PHYS_OFFSET);
	mi->end = memend_pfn << PAGE_SHIFT;

	}

	/*
	* Initialise the bootmem allocator for all nodes. This is called
	* early during the architecture specific initialisation.
	*/
	void __init bootmem_init(struct meminfo *mi)
	{
	struct node_info node_info;
	unsigned int bootmap_pfn;
	pg_data_t *pgdat = NODE_DATA(0);

	find_memend_and_nodes(mi, &node_info);

	bootmap_pfn = find_bootmap_pfn(mi, node_info.bootmap_pages);

	/*
	* Note that node 0 must always have some pages.
	*/
	if (node_info.end == 0)
	BUG();

	/*
	* Initialise the bootmem allocator.
	*/
	init_bootmem_node(pgdat, bootmap_pfn, node_info.start, node_info.end);

	/*
	* Register all available RAM in this node with the bootmem allocator.
	*/
	free_bootmem_node(pgdat, mi->bank->start, mi->bank->size);

	/*
	* Register the kernel text and data with bootmem.
	* Note: with XIP we dont register .text since
	* its in ROM.
	*/
	#ifdef CONFIG_XIP_KERNEL
	reserve_bootmem_node(pgdat, __pa(&_sdata), &_end - &_sdata);
	#else
	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
	#endif

	/*
	* And don't forget to reserve the allocator bitmap,
	* which will be freed later.
	*/
	reserve_bootmem_node(pgdat, bootmap_pfn << PAGE_SHIFT,
	node_info.bootmap_pages << PAGE_SHIFT);

	/*
	* These should likewise go elsewhere. They pre-reserve
	* the screen memory region at the start of main system
	* memory. FIXME - screen RAM is not 512K!
	*/
	reserve_bootmem_node(pgdat, 0x02000000, 0x00080000);

	#ifdef CONFIG_BLK_DEV_INITRD
	initrd_start = phys_initrd_start;
	initrd_end = initrd_start + phys_initrd_size;

	/* Achimedes machines only have one node, so initrd is in node 0 */
	#ifdef CONFIG_XIP_KERNEL
	/* Only reserve initrd space if it is in RAM */
	if(initrd_start && initrd_start < 0x03000000){
	#else
	if(initrd_start){
	#endif
	reserve_bootmem_node(pgdat, __pa(initrd_start),
	initrd_end - initrd_start);
	}
	#endif /* CONFIG_BLK_DEV_INITRD */


	}

	/*
	* paging_init() sets up the page tables, initialises the zone memory
	* maps, and sets up the zero page, bad page and bad page tables.
	*/
	void __init paging_init(struct meminfo *mi)
	{
	void *zero_page;
	unsigned long zone_size[MAX_NR_ZONES];
	unsigned long zhole_size[MAX_NR_ZONES];
	struct bootmem_data *bdata;
	pg_data_t *pgdat;
	int i;

	memcpy(&meminfo, mi, sizeof(meminfo));

	/*
	* allocate the zero page. Note that we count on this going ok.
	*/
	zero_page = alloc_bootmem_low_pages(PAGE_SIZE);

	/*
	* initialise the page tables.
	*/
	memtable_init(mi);
	flush_tlb_all();

	/*
	* initialise the zones in node 0 (archimedes have only 1 node)
	*/

	for (i = 0; i < MAX_NR_ZONES; i++) {
	zone_size[i] = 0;
	zhole_size[i] = 0;
	}

	pgdat = NODE_DATA(0);
	bdata = pgdat->bdata;
	zone_size[0] = bdata->node_low_pfn -
	(bdata->node_boot_start >> PAGE_SHIFT);
	if (!zone_size[0])
	BUG();
	pgdat->node_mem_map = NULL;
	free_area_init_node(0, pgdat, zone_size,
	bdata->node_boot_start >> PAGE_SHIFT, zhole_size);

	/*
	* finish off the bad pages once
	* the mem_map is initialised
	*/
	memzero(zero_page, PAGE_SIZE);
	empty_zero_page = virt_to_page(zero_page);
	}

	static inline void free_area(unsigned long addr, unsigned long end, char *s)
	{
	unsigned int size = (end - addr) >> 10;

	for (; addr < end; addr += PAGE_SIZE) {
	struct page *page = virt_to_page(addr);
	ClearPageReserved(page);
	init_page_count(page);
	free_page(addr);
	totalram_pages++;
	}

	if (size && s)
	printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);
	}

	/*
	* mem_init() marks the free areas in the mem_map and tells us how much
	* memory is free. This is done after various parts of the system have
	* claimed their memory after the kernel image.
	*/
	void __init mem_init(void)
	{
	unsigned int codepages, datapages, initpages;
	pg_data_t *pgdat = NODE_DATA(0);
	extern int sysctl_overcommit_memory;


	/* Note: data pages includes BSS */
	#ifdef CONFIG_XIP_KERNEL
	codepages = &_endtext - &_text;
	datapages = &_end - &_sdata;
	#else
	codepages = &_etext - &_text;
	datapages = &_end - &_etext;
	#endif
	initpages = &__init_end - &__init_begin;

	high_memory = (void *)__va(meminfo.end);
	max_mapnr = virt_to_page(high_memory) - mem_map;

	/* this will put all unused low memory onto the freelists */
	if (pgdat->node_spanned_pages != 0)
	totalram_pages += free_all_bootmem_node(pgdat);

	num_physpages = meminfo.bank[0].size >> PAGE_SHIFT;

	printk(KERN_INFO "Memory: %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));
	printk(KERN_NOTICE "Memory: %luKB available (%dK code, "
	"%dK data, %dK init)\n",
	(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
	codepages >> 10, datapages >> 10, initpages >> 10);

	/*
	* Turn on overcommit on tiny machines
	*/
	if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
	sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
	printk("Turning on overcommit\n");
	}
	}

	void free_initmem(void){
	#ifndef CONFIG_XIP_KERNEL
	free_area((unsigned long)(&__init_begin),
	(unsigned long)(&__init_end),
	"init");
	#endif
	}

	#ifdef CONFIG_BLK_DEV_INITRD

	static int keep_initrd;

	void free_initrd_mem(unsigned long start, unsigned long end)
	{
	#ifdef CONFIG_XIP_KERNEL
	/* Only bin initrd if it is in RAM... */
	if(!keep_initrd && start < 0x03000000)
	#else
	if (!keep_initrd)
	#endif
	free_area(start, end, "initrd");
	}

	static int __init keepinitrd_setup(char *__unused)
	{
	keep_initrd = 1;
	return 1;
	}

	__setup("keepinitrd", keepinitrd_setup);
	#endif