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/* *  linux/mm/vmalloc.c * *  Copyright (C) 1993  Linus Torvalds *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 *  SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000 *  Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 *  Numa awareness, Christoph Lameter, SGI, June 2005 */ #include <linux/mm.h>#include <linux/module.h>#include <linux/highmem.h>#include <linux/slab.h>#include <linux/spinlock.h>#include <linux/interrupt.h> #include <linux/vmalloc.h> #include <asm/uaccess.h>#include <asm/tlbflush.h>  DEFINE_RWLOCK(vmlist_lock);struct vm_struct *vmlist; static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,			    int node); static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end){	pte_t *pte; 	pte = pte_offset_kernel(pmd, addr);	do {		pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);		WARN_ON(!pte_none(ptent) && !pte_present(ptent));	} while (pte++, addr += PAGE_SIZE, addr != end);} static inline void vunmap_pmd_range(pud_t *pud, unsigned long addr,						unsigned long end){	pmd_t *pmd;	unsigned long next; 	pmd = pmd_offset(pud, addr);	do {		next = pmd_addr_end(addr, end);		if (pmd_none_or_clear_bad(pmd))			continue;		vunmap_pte_range(pmd, addr, next);	} while (pmd++, addr = next, addr != end);} static inline void vunmap_pud_range(pgd_t *pgd, unsigned long addr,						unsigned long end){	pud_t *pud;	unsigned long next; 	pud = pud_offset(pgd, addr);	do {		next = pud_addr_end(addr, end);		if (pud_none_or_clear_bad(pud))			continue;		vunmap_pmd_range(pud, addr, next);	} while (pud++, addr = next, addr != end);} void unmap_kernel_range(unsigned long addr, unsigned long size){	pgd_t *pgd;	unsigned long next;	unsigned long start = addr;	unsigned long end = addr + size; 	BUG_ON(addr >= end);	pgd = pgd_offset_k(addr);	flush_cache_vunmap(addr, end);	do {		next = pgd_addr_end(addr, end);		if (pgd_none_or_clear_bad(pgd))			continue;		vunmap_pud_range(pgd, addr, next);	} while (pgd++, addr = next, addr != end);	flush_tlb_kernel_range(start, end);} static void unmap_vm_area(struct vm_struct *area){	unmap_kernel_range((unsigned long)area->addr, area->size);} static int vmap_pte_range(pmd_t *pmd, unsigned long addr,			unsigned long end, pgprot_t prot, struct page ***pages){	pte_t *pte; 	pte = pte_alloc_kernel(pmd, addr);	if (!pte)		return -ENOMEM;	do {		struct page *page = **pages;		WARN_ON(!pte_none(*pte));		if (!page)			return -ENOMEM;		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));		(*pages)++;	} while (pte++, addr += PAGE_SIZE, addr != end);	return 0;} static inline int vmap_pmd_range(pud_t *pud, unsigned long addr,			unsigned long end, pgprot_t prot, struct page ***pages){	pmd_t *pmd;	unsigned long next; 	pmd = pmd_alloc(&init_mm, pud, addr);	if (!pmd)		return -ENOMEM;	do {		next = pmd_addr_end(addr, end);		if (vmap_pte_range(pmd, addr, next, prot, pages))			return -ENOMEM;	} while (pmd++, addr = next, addr != end);	return 0;} static inline int vmap_pud_range(pgd_t *pgd, unsigned long addr,			unsigned long end, pgprot_t prot, struct page ***pages){	pud_t *pud;	unsigned long next; 	pud = pud_alloc(&init_mm, pgd, addr);	if (!pud)		return -ENOMEM;	do {		next = pud_addr_end(addr, end);		if (vmap_pmd_range(pud, addr, next, prot, pages))			return -ENOMEM;	} while (pud++, addr = next, addr != end);	return 0;} int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages){	pgd_t *pgd;	unsigned long next;	unsigned long addr = (unsigned long) area->addr;	unsigned long end = addr + area->size - PAGE_SIZE;	int err; 	BUG_ON(addr >= end);	pgd = pgd_offset_k(addr);	do {		next = pgd_addr_end(addr, end);		err = vmap_pud_range(pgd, addr, next, prot, pages);		if (err)			break;	} while (pgd++, addr = next, addr != end);	flush_cache_vmap((unsigned long) area->addr, end);	return err;}EXPORT_SYMBOL_GPL(map_vm_area); /* * Map a vmalloc()-space virtual address to the physical page. */struct page *vmalloc_to_page(const void *vmalloc_addr){	unsigned long addr = (unsigned long) vmalloc_addr;	struct page *page = NULL;	pgd_t *pgd = pgd_offset_k(addr);	pud_t *pud;	pmd_t *pmd;	pte_t *ptep, pte; 	if (!pgd_none(*pgd)) {		pud = pud_offset(pgd, addr);		if (!pud_none(*pud)) {			pmd = pmd_offset(pud, addr);			if (!pmd_none(*pmd)) {				ptep = pte_offset_map(pmd, addr);				pte = *ptep;				if (pte_present(pte))					page = pte_page(pte);				pte_unmap(ptep);			}		}	}	return page;}EXPORT_SYMBOL(vmalloc_to_page); /* * Map a vmalloc()-space virtual address to the physical page frame number. */unsigned long vmalloc_to_pfn(const void *vmalloc_addr){	return page_to_pfn(vmalloc_to_page(vmalloc_addr));}EXPORT_SYMBOL(vmalloc_to_pfn); static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,					    unsigned long start, unsigned long end,					    int node, gfp_t gfp_mask){	struct vm_struct **p, *tmp, *area;	unsigned long align = 1;	unsigned long addr; 	BUG_ON(in_interrupt());	if (flags & VM_IOREMAP) {		int bit = fls(size); 		if (bit > IOREMAP_MAX_ORDER)			bit = IOREMAP_MAX_ORDER;		else if (bit < PAGE_SHIFT)			bit = PAGE_SHIFT; 		align = 1ul << bit;	}	addr = ALIGN(start, align);	size = PAGE_ALIGN(size);	if (unlikely(!size))		return NULL; 	area = kmalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); 	if (unlikely(!area))		return NULL; 	/*	 * We always allocate a guard page.	 */	size += PAGE_SIZE; 	write_lock(&vmlist_lock);	for (p = &vmlist; (tmp = *p) != NULL ;p = &tmp->next) {		if ((unsigned long)tmp->addr < addr) {			if((unsigned long)tmp->addr + tmp->size >= addr)				addr = ALIGN(tmp->size + 					     (unsigned long)tmp->addr, align);			continue;		}		if ((size + addr) < addr)			goto out;		if (size + addr <= (unsigned long)tmp->addr)			goto found;		addr = ALIGN(tmp->size + (unsigned long)tmp->addr, align);		if (addr > end - size)			goto out;	}	if ((size + addr) < addr)		goto out;	if (addr > end - size)		goto out; found:	area->next = *p;	*p = area; 	area->flags = flags;	area->addr = (void *)addr;	area->size = size;	area->pages = NULL;	area->nr_pages = 0;	area->phys_addr = 0;	write_unlock(&vmlist_lock); 	return area; out:	write_unlock(&vmlist_lock);	kfree(area);	if (printk_ratelimit())		printk(KERN_WARNING "allocation failed: out of vmalloc space - use vmalloc=<size> to increase size.\n");	return NULL;} struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,				unsigned long start, unsigned long end){	return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL);}EXPORT_SYMBOL_GPL(__get_vm_area); /** *	get_vm_area  -  reserve a contiguous kernel virtual area *	@size:		size of the area *	@flags:		%VM_IOREMAP for I/O mappings or VM_ALLOC * *	Search an area of @size in the kernel virtual mapping area, *	and reserved it for out purposes.  Returns the area descriptor *	on success or %NULL on failure. */struct vm_struct *get_vm_area(unsigned long size, unsigned long flags){	return __get_vm_area(size, flags, VMALLOC_START, VMALLOC_END);} struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags,				   int node, gfp_t gfp_mask){	return __get_vm_area_node(size, flags, VMALLOC_START, VMALLOC_END, node,				  gfp_mask);} /* Caller must hold vmlist_lock */static struct vm_struct *__find_vm_area(const void *addr){	struct vm_struct *tmp; 	for (tmp = vmlist; tmp != NULL; tmp = tmp->next) {		 if (tmp->addr == addr)			break;	} 	return tmp;} /* Caller must hold vmlist_lock */static struct vm_struct *__remove_vm_area(const void *addr){	struct vm_struct **p, *tmp; 	for (p = &vmlist ; (tmp = *p) != NULL ;p = &tmp->next) {		 if (tmp->addr == addr)			 goto found;	}	return NULL; found:	unmap_vm_area(tmp);	*p = tmp->next; 	/*	 * Remove the guard page.	 */	tmp->size -= PAGE_SIZE;	return tmp;} /** *	remove_vm_area  -  find and remove a continuous kernel virtual area *	@addr:		base address * *	Search for the kernel VM area starting at @addr, and remove it. *	This function returns the found VM area, but using it is NOT safe *	on SMP machines, except for its size or flags. */struct vm_struct *remove_vm_area(const void *addr){	struct vm_struct *v;	write_lock(&vmlist_lock);	v = __remove_vm_area(addr);	write_unlock(&vmlist_lock);	return v;} static void __vunmap(const void *addr, int deallocate_pages){	struct vm_struct *area; 	if (!addr)		return; 	if ((PAGE_SIZE-1) & (unsigned long)addr) {		printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr);		WARN_ON(1);		return;	} 	area = remove_vm_area(addr);	if (unlikely(!area)) {		printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",				addr);		WARN_ON(1);		return;	} 	debug_check_no_locks_freed(addr, area->size); 	if (deallocate_pages) {		int i; 		for (i = 0; i < area->nr_pages; i++) {			struct page *page = area->pages[i]; 			BUG_ON(!page);			__free_page(page);		} 		if (area->flags & VM_VPAGES)			vfree(area->pages);		else			kfree(area->pages);	} 	kfree(area);	return;} /** *	vfree  -  release memory allocated by vmalloc() *	@addr:		memory base address * *	Free the virtually continuous memory area starting at @addr, as *	obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is *	NULL, no operation is performed. * *	Must not be called in interrupt context. */void vfree(const void *addr){	BUG_ON(in_interrupt());	__vunmap(addr, 1);}EXPORT_SYMBOL(vfree); /** *	vunmap  -  release virtual mapping obtained by vmap() *	@addr:		memory base address * *	Free the virtually contiguous memory area starting at @addr, *	which was created from the page array passed to vmap(). * *	Must not be called in interrupt context. */void vunmap(const void *addr){	BUG_ON(in_interrupt());	__vunmap(addr, 0);}EXPORT_SYMBOL(vunmap); /** *	vmap  -  map an array of pages into virtually contiguous space *	@pages:		array of page pointers *	@count:		number of pages to map *	@flags:		vm_area->flags *	@prot:		page protection for the mapping * *	Maps @count pages from @pages into contiguous kernel virtual *	space. */void *vmap(struct page **pages, unsigned int count,		unsigned long flags, pgprot_t prot){	struct vm_struct *area; 	if (count > num_physpages)		return NULL; 	area = get_vm_area((count << PAGE_SHIFT), flags);	if (!area)		return NULL;	if (map_vm_area(area, prot, &pages)) {		vunmap(area->addr);		return NULL;	} 	return area->addr;}EXPORT_SYMBOL(vmap); static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,				 pgprot_t prot, int node){	struct page **pages;	unsigned int nr_pages, array_size, i; 	nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;	array_size = (nr_pages * sizeof(struct page *)); 	area->nr_pages = nr_pages;	/* Please note that the recursion is strictly bounded. */	if (array_size > PAGE_SIZE) {		pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO,					PAGE_KERNEL, node);		area->flags |= VM_VPAGES;	} else {		pages = kmalloc_node(array_size,				(gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO,				node);	}	area->pages = pages;	if (!area->pages) {		remove_vm_area(area->addr);		kfree(area);		return NULL;	} 	for (i = 0; i < area->nr_pages; i++) {		struct page *page; 		if (node < 0)

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