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

 /* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $
  *
  *  linux/arch/sh/mm/init.c
  *
  *  Copyright (C) 1999  Niibe Yutaka
  *  Copyright (C) 2002, 2004  Paul Mundt
  *
  *  Based on linux/arch/i386/mm/init.c:
  *   Copyright (C) 1995  Linus Torvalds
  */

 #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/highmem.h>
 #include <linux/bootmem.h>
 #include <linux/pagemap.h>

 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/mmu_context.h>
 #include <asm/io.h>
 #include <asm/tlb.h>
 #include <asm/cacheflush.h>
 #include <asm/cache.h>

 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 pgd_t swapper_pg_dir[PTRS_PER_PGD];

 /*
  * Cache of MMU context last used.
  */
 unsigned long mmu_context_cache = NO_CONTEXT;

 #ifdef CONFIG_MMU
 /* It'd be good if these lines were in the standard header file. */
 #define START_PFN	(NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
 #define MAX_LOW_PFN	(NODE_DATA(0)->bdata->node_low_pfn)
 #endif

 void (*copy_page)(void *from, void *to);
 void (*clear_page)(void *to);

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

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

 static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
 {
 	pgd_t *pgd;
 	pmd_t *pmd;
 	pte_t *pte;

 	pgd = swapper_pg_dir + pgd_index(addr);
 	if (pgd_none(*pgd)) {
 		pgd_ERROR(*pgd);
 		return;
 	}

 	pmd = pmd_offset(pgd, addr);
 	if (pmd_none(*pmd)) {
 		pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
 		set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
 		if (pte != pte_offset_kernel(pmd, 0)) {
 			pmd_ERROR(*pmd);
 			return;
 		}
 	}

 	pte = pte_offset_kernel(pmd, addr);
 	if (!pte_none(*pte)) {
 		pte_ERROR(*pte);
 		return;
 	}

 	set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));

 	__flush_tlb_page(get_asid(), addr);
 }

 /*
  * As a performance optimization, other platforms preserve the fixmap mapping
  * across a context switch, we don't presently do this, but this could be done
  * in a similar fashion as to the wired TLB interface that sh64 uses (by way
  * of the memorry mapped UTLB configuration) -- this unfortunately forces us to
  * give up a TLB entry for each mapping we want to preserve. While this may be
  * viable for a small number of fixmaps, it's not particularly useful for
  * everything and needs to be carefully evaluated. (ie, we may want this for
  * the vsyscall page).
  *
  * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
  * in at __set_fixmap() time to determine the appropriate behavior to follow.
  *
  *					 -- PFM.
  */
 void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
 {
 	unsigned long address = __fix_to_virt(idx);

 	if (idx >= __end_of_fixed_addresses) {
 		BUG();
 		return;
 	}

 	set_pte_phys(address, phys, prot);
 }

 /* References to section boundaries */

 extern char _text, _etext, _edata, __bss_start, _end;
 extern char __init_begin, __init_end;

 /*
  * paging_init() sets up the page tables
  *
  * This routines also unmaps the page at virtual kernel address 0, so
  * that we can trap those pesky NULL-reference errors in the kernel.
  */
 void __init paging_init(void)
 {
 	unsigned long zones_size[MAX_NR_ZONES] = { 0, };

 	/*
 	 * Setup some defaults for the zone sizes.. these should be safe
 	 * regardless of distcontiguous memory or MMU settings.
 	 */
 	zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
 	zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT;
 #ifdef CONFIG_HIGHMEM
 	zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT;
 #endif

 #ifdef CONFIG_MMU
 	/*
 	 * If we have an MMU, and want to be using it .. we need to adjust
 	 * the zone sizes accordingly, in addition to turning it on.
 	 */
 	{
 		unsigned long max_dma, low, start_pfn;
 		pgd_t *pg_dir;
 		int i;

 		/* We don't need kernel mapping as hardware support that. */
 		pg_dir = swapper_pg_dir;

 		for (i = 0; i < PTRS_PER_PGD; i++)
 			pgd_val(pg_dir[i]) = 0;

 		/* Turn on the MMU */
 		enable_mmu();

 		/* Fixup the zone sizes */
 		start_pfn = START_PFN;
 		max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
 		low = MAX_LOW_PFN;

 		if (low < max_dma) {
 			zones_size[ZONE_DMA] = low - start_pfn;
 			zones_size[ZONE_NORMAL] = 0;
 		} else {
 			zones_size[ZONE_DMA] = max_dma - start_pfn;
 			zones_size[ZONE_NORMAL] = low - max_dma;
 		}
 	}

 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
 	/*
 	 * If we don't have CONFIG_MMU set and the processor in question
 	 * still has an MMU, care needs to be taken to make sure it doesn't
 	 * stay on.. Since the boot loader could have potentially already
 	 * turned it on, and we clearly don't want it, we simply turn it off.
 	 *
 	 * We don't need to do anything special for the zone sizes, since the
 	 * default values that were already configured up above should be
 	 * satisfactory.
 	 */
 	disable_mmu();
 #endif
 	NODE_DATA(0)->node_mem_map = NULL;
 	free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
 }

 void __init mem_init(void)
 {
 	extern unsigned long empty_zero_page[1024];
 	int codesize, reservedpages, datasize, initsize;
 	int tmp;
 	extern unsigned long memory_start;

 #ifdef CONFIG_MMU
 	high_memory = (void *)__va(MAX_LOW_PFN * PAGE_SIZE);
 #else
 	extern unsigned long memory_end;

 	high_memory = (void *)(memory_end & PAGE_MASK);
 #endif

 	max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start);

 	/* clear the zero-page */
 	memset(empty_zero_page, 0, PAGE_SIZE);
 	__flush_wback_region(empty_zero_page, PAGE_SIZE);

 	/*
 	 * Setup wrappers for copy/clear_page(), these will get overridden
 	 * later in the boot process if a better method is available.
 	 */
 	copy_page = copy_page_slow;
 	clear_page = clear_page_slow;

 	/* this will put all low memory onto the freelists */
 	totalram_pages += free_all_bootmem_node(NODE_DATA(0));
 	reservedpages = 0;
 	for (tmp = 0; tmp < num_physpages; tmp++)
 		/*
 		 * Only count reserved RAM pages
 		 */
 		if (PageReserved(mem_map+tmp))
 			reservedpages++;

 	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;

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

 	p3_cache_init();
 }

 void free_initmem(void)
 {
 	unsigned long addr;

 	addr = (unsigned long)(&__init_begin);
 	for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 		ClearPageReserved(virt_to_page(addr));
 		init_page_count(virt_to_page(addr));
 		free_page(addr);
 		totalram_pages++;
 	}
 	printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
 }

 #ifdef CONFIG_BLK_DEV_INITRD
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 	unsigned long p;
 	for (p = start; p < end; p += PAGE_SIZE) {
 		ClearPageReserved(virt_to_page(p));
 		init_page_count(virt_to_page(p));
 		free_page(p);
 		totalram_pages++;
 	}
 	printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 }
 #endif
	/* $Id: init.c,v 1.19 2004/02/21 04:42:16 kkojima Exp $
	*
	* linux/arch/sh/mm/init.c
	*
	* Copyright (C) 1999 Niibe Yutaka
	* Copyright (C) 2002, 2004 Paul Mundt
	*
	* Based on linux/arch/i386/mm/init.c:
	* Copyright (C) 1995 Linus Torvalds
	*/

	#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/highmem.h>
	#include <linux/bootmem.h>
	#include <linux/pagemap.h>

	#include <asm/processor.h>
	#include <asm/system.h>
	#include <asm/uaccess.h>
	#include <asm/pgtable.h>
	#include <asm/pgalloc.h>
	#include <asm/mmu_context.h>
	#include <asm/io.h>
	#include <asm/tlb.h>
	#include <asm/cacheflush.h>
	#include <asm/cache.h>

	DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
	pgd_t swapper_pg_dir[PTRS_PER_PGD];

	/*
	* Cache of MMU context last used.
	*/
	unsigned long mmu_context_cache = NO_CONTEXT;

	#ifdef CONFIG_MMU
	/* It'd be good if these lines were in the standard header file. */
	#define START_PFN (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
	#define MAX_LOW_PFN (NODE_DATA(0)->bdata->node_low_pfn)
	#endif

	void (copy_page)(void from, void *to);
	void (clear_page)(void to);

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

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

	static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
	{
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;

	pgd = swapper_pg_dir + pgd_index(addr);
	if (pgd_none(*pgd)) {
	pgd_ERROR(*pgd);
	return;
	}

	pmd = pmd_offset(pgd, addr);
	if (pmd_none(*pmd)) {
	pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
	set_pmd(pmd, __pmd(__pa(pte) \| _KERNPG_TABLE \| _PAGE_USER));
	if (pte != pte_offset_kernel(pmd, 0)) {
	pmd_ERROR(*pmd);
	return;
	}
	}

	pte = pte_offset_kernel(pmd, addr);
	if (!pte_none(*pte)) {
	pte_ERROR(*pte);
	return;
	}

	set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));

	__flush_tlb_page(get_asid(), addr);
	}

	/*
	* As a performance optimization, other platforms preserve the fixmap mapping
	* across a context switch, we don't presently do this, but this could be done
	* in a similar fashion as to the wired TLB interface that sh64 uses (by way
	* of the memorry mapped UTLB configuration) -- this unfortunately forces us to
	* give up a TLB entry for each mapping we want to preserve. While this may be
	* viable for a small number of fixmaps, it's not particularly useful for
	* everything and needs to be carefully evaluated. (ie, we may want this for
	* the vsyscall page).
	*
	* XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
	* in at __set_fixmap() time to determine the appropriate behavior to follow.
	*
	* -- PFM.
	*/
	void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
	{
	unsigned long address = __fix_to_virt(idx);

	if (idx >= __end_of_fixed_addresses) {
	BUG();
	return;
	}

	set_pte_phys(address, phys, prot);
	}

	/* References to section boundaries */

	extern char _text, _etext, _edata, __bss_start, _end;
	extern char __init_begin, __init_end;

	/*
	* paging_init() sets up the page tables
	*
	* This routines also unmaps the page at virtual kernel address 0, so
	* that we can trap those pesky NULL-reference errors in the kernel.
	*/
	void __init paging_init(void)
	{
	unsigned long zones_size[MAX_NR_ZONES] = { 0, };

	/*
	* Setup some defaults for the zone sizes.. these should be safe
	* regardless of distcontiguous memory or MMU settings.
	*/
	zones_size[ZONE_DMA] = 0 >> PAGE_SHIFT;
	zones_size[ZONE_NORMAL] = __MEMORY_SIZE >> PAGE_SHIFT;
	#ifdef CONFIG_HIGHMEM
	zones_size[ZONE_HIGHMEM] = 0 >> PAGE_SHIFT;
	#endif

	#ifdef CONFIG_MMU
	/*
	* If we have an MMU, and want to be using it .. we need to adjust
	* the zone sizes accordingly, in addition to turning it on.
	*/
	{
	unsigned long max_dma, low, start_pfn;
	pgd_t *pg_dir;
	int i;

	/* We don't need kernel mapping as hardware support that. */
	pg_dir = swapper_pg_dir;

	for (i = 0; i < PTRS_PER_PGD; i++)
	pgd_val(pg_dir[i]) = 0;

	/* Turn on the MMU */
	enable_mmu();

	/* Fixup the zone sizes */
	start_pfn = START_PFN;
	max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
	low = MAX_LOW_PFN;

	if (low < max_dma) {
	zones_size[ZONE_DMA] = low - start_pfn;
	zones_size[ZONE_NORMAL] = 0;
	} else {
	zones_size[ZONE_DMA] = max_dma - start_pfn;
	zones_size[ZONE_NORMAL] = low - max_dma;
	}
	}

	#elif defined(CONFIG_CPU_SH3) \|\| defined(CONFIG_CPU_SH4)
	/*
	* If we don't have CONFIG_MMU set and the processor in question
	* still has an MMU, care needs to be taken to make sure it doesn't
	* stay on.. Since the boot loader could have potentially already
	* turned it on, and we clearly don't want it, we simply turn it off.
	*
	* We don't need to do anything special for the zone sizes, since the
	* default values that were already configured up above should be
	* satisfactory.
	*/
	disable_mmu();
	#endif
	NODE_DATA(0)->node_mem_map = NULL;
	free_area_init_node(0, NODE_DATA(0), zones_size, __MEMORY_START >> PAGE_SHIFT, 0);
	}

	void __init mem_init(void)
	{
	extern unsigned long empty_zero_page[1024];
	int codesize, reservedpages, datasize, initsize;
	int tmp;
	extern unsigned long memory_start;

	#ifdef CONFIG_MMU
	high_memory = (void )__va(MAX_LOW_PFN PAGE_SIZE);
	#else
	extern unsigned long memory_end;

	high_memory = (void *)(memory_end & PAGE_MASK);
	#endif

	max_mapnr = num_physpages = MAP_NR(high_memory) - MAP_NR(memory_start);

	/* clear the zero-page */
	memset(empty_zero_page, 0, PAGE_SIZE);
	__flush_wback_region(empty_zero_page, PAGE_SIZE);

	/*
	* Setup wrappers for copy/clear_page(), these will get overridden
	* later in the boot process if a better method is available.
	*/
	copy_page = copy_page_slow;
	clear_page = clear_page_slow;

	/* this will put all low memory onto the freelists */
	totalram_pages += free_all_bootmem_node(NODE_DATA(0));
	reservedpages = 0;
	for (tmp = 0; tmp < num_physpages; tmp++)
	/*
	* Only count reserved RAM pages
	*/
	if (PageReserved(mem_map+tmp))
	reservedpages++;

	codesize = (unsigned long) &_etext - (unsigned long) &_text;
	datasize = (unsigned long) &_edata - (unsigned long) &_etext;
	initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;

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

	p3_cache_init();
	}

	void free_initmem(void)
	{
	unsigned long addr;

	addr = (unsigned long)(&__init_begin);
	for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
	ClearPageReserved(virt_to_page(addr));
	init_page_count(virt_to_page(addr));
	free_page(addr);
	totalram_pages++;
	}
	printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
	}

	#ifdef CONFIG_BLK_DEV_INITRD
	void free_initrd_mem(unsigned long start, unsigned long end)
	{
	unsigned long p;
	for (p = start; p < end; p += PAGE_SIZE) {
	ClearPageReserved(virt_to_page(p));
	init_page_count(virt_to_page(p));
	free_page(p);
	totalram_pages++;
	}
	printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
	}
	#endif