arch/sh/mm/init.c - kernel/prism - Git at Google

 /*
  * linux/arch/sh/mm/init.c
  *
  *  Copyright (C) 1999  Niibe Yutaka
  *  Copyright (C) 2002 - 2007  Paul Mundt
  *
  *  Based on linux/arch/i386/mm/init.c:
  *   Copyright (C) 1995  Linus Torvalds
  */
 #include <linux/mm.h>
 #include <linux/swap.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/proc_fs.h>
 #include <linux/pagemap.h>
 #include <linux/percpu.h>
 #include <linux/io.h>
 #include <asm/mmu_context.h>
 #include <asm/tlb.h>
 #include <asm/cacheflush.h>
 #include <asm/sections.h>
 #include <asm/cache.h>

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

 #ifdef CONFIG_SUPERH32
 /*
  * Handle trivial transitions between cached and uncached
  * segments, making use of the 1:1 mapping relationship in
  * 512MB lowmem.
  *
  * This is the offset of the uncached section from its cached alias.
  * Default value only valid in 29 bit mode, in 32bit mode will be
  * overridden in pmb_init.
  */
 unsigned long cached_to_uncached = P2SEG - P1SEG;
 #endif

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

 	pgd = pgd_offset_k(addr);
 	if (pgd_none(*pgd)) {
 		pgd_ERROR(*pgd);
 		return;
 	}

 	pud = pud_alloc(NULL, pgd, addr);
 	if (unlikely(!pud)) {
 		pud_ERROR(*pud);
 		return;
 	}

 	pmd = pmd_alloc(NULL, pud, addr);
 	if (unlikely(!pmd)) {
 		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));
 	local_flush_tlb_one(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 memory 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);
 }

 void __init page_table_range_init(unsigned long start, unsigned long end,
 					 pgd_t *pgd_base)
 {
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
 	int i, j, k;
 	unsigned long vaddr;

 	vaddr = start;
 	i = __pgd_offset(vaddr);
 	j = __pud_offset(vaddr);
 	k = __pmd_offset(vaddr);
 	pgd = pgd_base + i;

 	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 		pud = (pud_t *)pgd;
 		for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 			pmd = (pmd_t *)pud;
 			for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 				if (pmd_none(*pmd)) {
 					pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 					pmd_populate_kernel(&init_mm, pmd, pte);
 					BUG_ON(pte != pte_offset_kernel(pmd, 0));
 				}
 				vaddr += PMD_SIZE;
 			}
 			k = 0;
 		}
 		j = 0;
 	}
 }
 #endif	/* CONFIG_MMU */

 /*
  * paging_init() sets up the page tables
  */
 void __init paging_init(void)
 {
 	unsigned long max_zone_pfns[MAX_NR_ZONES];
 	unsigned long vaddr, end;
 	int nid;

 	/* We don't need to map the kernel through the TLB, as
 	 * it is permanatly mapped using P1. So clear the
 	 * entire pgd. */
 	memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));

 	/* Set an initial value for the MMU.TTB so we don't have to
 	 * check for a null value. */
 	set_TTB(swapper_pg_dir);

 	/*
 	 * Populate the relevant portions of swapper_pg_dir so that
 	 * we can use the fixmap entries without calling kmalloc.
 	 * pte's will be filled in by __set_fixmap().
 	 */
 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 	end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 	page_table_range_init(vaddr, end, swapper_pg_dir);

 	kmap_coherent_init();

 	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));

 	for_each_online_node(nid) {
 		pg_data_t *pgdat = NODE_DATA(nid);
 		unsigned long low, start_pfn;

 		start_pfn = pgdat->bdata->node_min_pfn;
 		low = pgdat->bdata->node_low_pfn;

 		if (max_zone_pfns[ZONE_NORMAL] < low)
 			max_zone_pfns[ZONE_NORMAL] = low;

 		printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 		       nid, start_pfn, low);
 	}

 	free_area_init_nodes(max_zone_pfns);

 	/* Set up the uncached fixmap */
 	set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
 }

 void __init mem_init(void)
 {
 	int codesize, datasize, initsize;
 	int nid;

 	num_physpages = 0;
 	high_memory = NULL;

 	for_each_online_node(nid) {
 		pg_data_t *pgdat = NODE_DATA(nid);
 		unsigned long node_pages = 0;
 		void *node_high_memory;

 		num_physpages += pgdat->node_present_pages;

 		if (pgdat->node_spanned_pages)
 			node_pages = free_all_bootmem_node(pgdat);

 		totalram_pages += node_pages;

 		node_high_memory = (void *)__va((pgdat->node_start_pfn +
 						 pgdat->node_spanned_pages) <<
 						 PAGE_SHIFT);
 		if (node_high_memory > high_memory)
 			high_memory = node_high_memory;
 	}

 	/* Set this up early, so we can take care of the zero page */
 	cpu_cache_init();

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

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

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

 	/* Initialize the vDSO */
 	vsyscall_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: %ldk freed\n",
 	       ((unsigned long)&__init_end -
 	        (unsigned long)&__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

 #if THREAD_SHIFT < PAGE_SHIFT
 static struct kmem_cache *thread_info_cache;

 struct thread_info *alloc_thread_info(struct task_struct *tsk)
 {
 	struct thread_info *ti;

 	ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
 	if (unlikely(ti == NULL))
 		return NULL;
 #ifdef CONFIG_DEBUG_STACK_USAGE
 	memset(ti, 0, THREAD_SIZE);
 #endif
 	return ti;
 }

 void free_thread_info(struct thread_info *ti)
 {
 	kmem_cache_free(thread_info_cache, ti);
 }

 void thread_info_cache_init(void)
 {
 	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
 					      THREAD_SIZE, 0, NULL);
 	BUG_ON(thread_info_cache == NULL);
 }
 #endif /* THREAD_SHIFT < PAGE_SHIFT */

 #ifdef CONFIG_MEMORY_HOTPLUG
 int arch_add_memory(int nid, u64 start, u64 size)
 {
 	pg_data_t *pgdat;
 	unsigned long start_pfn = start >> PAGE_SHIFT;
 	unsigned long nr_pages = size >> PAGE_SHIFT;
 	int ret;

 	pgdat = NODE_DATA(nid);

 	/* We only have ZONE_NORMAL, so this is easy.. */
 	ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
 				start_pfn, nr_pages);
 	if (unlikely(ret))
 		printk("%s: Failed, __add_pages() == %d\n", __func__, ret);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(arch_add_memory);

 #ifdef CONFIG_NUMA
 int memory_add_physaddr_to_nid(u64 addr)
 {
 	/* Node 0 for now.. */
 	return 0;
 }
 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 #endif
 #endif /* CONFIG_MEMORY_HOTPLUG */
	/*
	* linux/arch/sh/mm/init.c
	*
	* Copyright (C) 1999 Niibe Yutaka
	* Copyright (C) 2002 - 2007 Paul Mundt
	*
	* Based on linux/arch/i386/mm/init.c:
	* Copyright (C) 1995 Linus Torvalds
	*/
	#include <linux/mm.h>
	#include <linux/swap.h>
	#include <linux/init.h>
	#include <linux/bootmem.h>
	#include <linux/proc_fs.h>
	#include <linux/pagemap.h>
	#include <linux/percpu.h>
	#include <linux/io.h>
	#include <asm/mmu_context.h>
	#include <asm/tlb.h>
	#include <asm/cacheflush.h>
	#include <asm/sections.h>
	#include <asm/cache.h>

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

	#ifdef CONFIG_SUPERH32
	/*
	* Handle trivial transitions between cached and uncached
	* segments, making use of the 1:1 mapping relationship in
	* 512MB lowmem.
	*
	* This is the offset of the uncached section from its cached alias.
	* Default value only valid in 29 bit mode, in 32bit mode will be
	* overridden in pmb_init.
	*/
	unsigned long cached_to_uncached = P2SEG - P1SEG;
	#endif

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

	pgd = pgd_offset_k(addr);
	if (pgd_none(*pgd)) {
	pgd_ERROR(*pgd);
	return;
	}

	pud = pud_alloc(NULL, pgd, addr);
	if (unlikely(!pud)) {
	pud_ERROR(*pud);
	return;
	}

	pmd = pmd_alloc(NULL, pud, addr);
	if (unlikely(!pmd)) {
	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));
	local_flush_tlb_one(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 memory 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);
	}

	void __init page_table_range_init(unsigned long start, unsigned long end,
	pgd_t *pgd_base)
	{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
	int i, j, k;
	unsigned long vaddr;

	vaddr = start;
	i = __pgd_offset(vaddr);
	j = __pud_offset(vaddr);
	k = __pmd_offset(vaddr);
	pgd = pgd_base + i;

	for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
	pud = (pud_t *)pgd;
	for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
	pmd = (pmd_t *)pud;
	for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
	if (pmd_none(*pmd)) {
	pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
	pmd_populate_kernel(&init_mm, pmd, pte);
	BUG_ON(pte != pte_offset_kernel(pmd, 0));
	}
	vaddr += PMD_SIZE;
	}
	k = 0;
	}
	j = 0;
	}
	}
	#endif /* CONFIG_MMU */

	/*
	* paging_init() sets up the page tables
	*/
	void __init paging_init(void)
	{
	unsigned long max_zone_pfns[MAX_NR_ZONES];
	unsigned long vaddr, end;
	int nid;

	/* We don't need to map the kernel through the TLB, as
	* it is permanatly mapped using P1. So clear the
	* entire pgd. */
	memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));

	/* Set an initial value for the MMU.TTB so we don't have to
	* check for a null value. */
	set_TTB(swapper_pg_dir);

	/*
	* Populate the relevant portions of swapper_pg_dir so that
	* we can use the fixmap entries without calling kmalloc.
	* pte's will be filled in by __set_fixmap().
	*/
	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
	end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
	page_table_range_init(vaddr, end, swapper_pg_dir);

	kmap_coherent_init();

	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));

	for_each_online_node(nid) {
	pg_data_t *pgdat = NODE_DATA(nid);
	unsigned long low, start_pfn;

	start_pfn = pgdat->bdata->node_min_pfn;
	low = pgdat->bdata->node_low_pfn;

	if (max_zone_pfns[ZONE_NORMAL] < low)
	max_zone_pfns[ZONE_NORMAL] = low;

	printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
	nid, start_pfn, low);
	}

	free_area_init_nodes(max_zone_pfns);

	/* Set up the uncached fixmap */
	set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
	}

	void __init mem_init(void)
	{
	int codesize, datasize, initsize;
	int nid;

	num_physpages = 0;
	high_memory = NULL;

	for_each_online_node(nid) {
	pg_data_t *pgdat = NODE_DATA(nid);
	unsigned long node_pages = 0;
	void *node_high_memory;

	num_physpages += pgdat->node_present_pages;

	if (pgdat->node_spanned_pages)
	node_pages = free_all_bootmem_node(pgdat);

	totalram_pages += node_pages;

	node_high_memory = (void *)__va((pgdat->node_start_pfn +
	pgdat->node_spanned_pages) <<
	PAGE_SHIFT);
	if (node_high_memory > high_memory)
	high_memory = node_high_memory;
	}

	/* Set this up early, so we can take care of the zero page */
	cpu_cache_init();

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

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

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

	/* Initialize the vDSO */
	vsyscall_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: %ldk freed\n",
	((unsigned long)&__init_end -
	(unsigned long)&__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

	#if THREAD_SHIFT < PAGE_SHIFT
	static struct kmem_cache *thread_info_cache;

	struct thread_info alloc_thread_info(struct task_struct tsk)
	{
	struct thread_info *ti;

	ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
	if (unlikely(ti == NULL))
	return NULL;
	#ifdef CONFIG_DEBUG_STACK_USAGE
	memset(ti, 0, THREAD_SIZE);
	#endif
	return ti;
	}

	void free_thread_info(struct thread_info *ti)
	{
	kmem_cache_free(thread_info_cache, ti);
	}

	void thread_info_cache_init(void)
	{
	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
	THREAD_SIZE, 0, NULL);
	BUG_ON(thread_info_cache == NULL);
	}
	#endif /* THREAD_SHIFT < PAGE_SHIFT */

	#ifdef CONFIG_MEMORY_HOTPLUG
	int arch_add_memory(int nid, u64 start, u64 size)
	{
	pg_data_t *pgdat;
	unsigned long start_pfn = start >> PAGE_SHIFT;
	unsigned long nr_pages = size >> PAGE_SHIFT;
	int ret;

	pgdat = NODE_DATA(nid);

	/* We only have ZONE_NORMAL, so this is easy.. */
	ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
	start_pfn, nr_pages);
	if (unlikely(ret))
	printk("%s: Failed, __add_pages() == %d\n", __func__, ret);

	return ret;
	}
	EXPORT_SYMBOL_GPL(arch_add_memory);

	#ifdef CONFIG_NUMA
	int memory_add_physaddr_to_nid(u64 addr)
	{
	/* Node 0 for now.. */
	return 0;
	}
	EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
	#endif
	#endif /* CONFIG_MEMORY_HOTPLUG */