include/linux/hugetlb.h

#ifndef _LINUX_HUGETLB_H
#define _LINUX_HUGETLB_H

#include <linux/fs.h>

#ifdef CONFIG_HUGETLB_PAGE

#include <linux/mempolicy.h>
#include <linux/shm.h>
#include <asm/tlbflush.h>

struct ctl_table;

static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
{
	return vma->vm_flags & VM_HUGETLB;
}

void reset_vma_resv_huge_pages(struct vm_area_struct *vma);
int hugetlb_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
int hugetlb_overcommit_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
int hugetlb_treat_movable_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *);
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int, int);
void unmap_hugepage_range(struct vm_area_struct *,
			unsigned long, unsigned long, struct page *);
void __unmap_hugepage_range(struct vm_area_struct *,
			unsigned long, unsigned long, struct page *);
int hugetlb_prefault(struct address_space *, struct vm_area_struct *);
int hugetlb_report_meminfo(char *);
int hugetlb_report_node_meminfo(int, char *);
unsigned long hugetlb_total_pages(void);
int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
			unsigned long address, int write_access);
int hugetlb_reserve_pages(struct inode *inode, long from, long to,
						struct vm_area_struct *vma);
void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);

extern unsigned long hugepages_treat_as_movable;
extern const unsigned long hugetlb_zero, hugetlb_infinity;
extern int sysctl_hugetlb_shm_group;

/* arch callbacks */

pte_t *huge_pte_alloc(struct mm_struct *mm,
			unsigned long addr, unsigned long sz);
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr);
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep);
struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
			      int write);
struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
				pmd_t *pmd, int write);
int pmd_huge(pmd_t pmd);
void hugetlb_change_protection(struct vm_area_struct *vma,
		unsigned long address, unsigned long end, pgprot_t newprot);

#else /* !CONFIG_HUGETLB_PAGE */

static inline int is_vm_hugetlb_page(struct vm_area_struct *vma)
{
	return 0;
}

static inline void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
{
}

static inline unsigned long hugetlb_total_pages(void)
{
	return 0;
}

#define follow_hugetlb_page(m,v,p,vs,a,b,i,w)	({ BUG(); 0; })
#define follow_huge_addr(mm, addr, write)	ERR_PTR(-EINVAL)
#define copy_hugetlb_page_range(src, dst, vma)	({ BUG(); 0; })
#define hugetlb_prefault(mapping, vma)		({ BUG(); 0; })
#define unmap_hugepage_range(vma, start, end, page)	BUG()
#define hugetlb_report_meminfo(buf)		0
#define hugetlb_report_node_meminfo(n, buf)	0
#define follow_huge_pmd(mm, addr, pmd, write)	NULL
#define prepare_hugepage_range(file, addr, len)	(-EINVAL)
#define pmd_huge(x)	0
#define is_hugepage_only_range(mm, addr, len)	0
#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
#define hugetlb_fault(mm, vma, addr, write)	({ BUG(); 0; })

#define hugetlb_change_protection(vma, address, end, newprot)

#ifndef HPAGE_MASK
#define HPAGE_MASK	PAGE_MASK		/* Keep the compiler happy */
#define HPAGE_SIZE	PAGE_SIZE
#endif

#endif /* !CONFIG_HUGETLB_PAGE */

#ifdef CONFIG_HUGETLBFS
struct hugetlbfs_config {
	uid_t   uid;
	gid_t   gid;
	umode_t mode;
	long	nr_blocks;
	long	nr_inodes;
};

struct hugetlbfs_sb_info {
	long	max_blocks;   /* blocks allowed */
	long	free_blocks;  /* blocks free */
	long	max_inodes;   /* inodes allowed */
	long	free_inodes;  /* inodes free */
	spinlock_t	stat_lock;
};


struct hugetlbfs_inode_info {
	struct shared_policy policy;
	struct inode vfs_inode;
};

static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)
{
	return container_of(inode, struct hugetlbfs_inode_info, vfs_inode);
}

static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
{
	return sb->s_fs_info;
}

extern const struct file_operations hugetlbfs_file_operations;
extern struct vm_operations_struct hugetlb_vm_ops;
struct file *hugetlb_file_setup(const char *name, size_t);
int hugetlb_get_quota(struct address_space *mapping, long delta);
void hugetlb_put_quota(struct address_space *mapping, long delta);

static inline int is_file_hugepages(struct file *file)
{
	if (file->f_op == &hugetlbfs_file_operations)
		return 1;
	if (is_file_shm_hugepages(file))
		return 1;

	return 0;
}

static inline void set_file_hugepages(struct file *file)
{
	file->f_op = &hugetlbfs_file_operations;
}
#else /* !CONFIG_HUGETLBFS */

#define is_file_hugepages(file)		0
#define set_file_hugepages(file)	BUG()
#define hugetlb_file_setup(name,size)	ERR_PTR(-ENOSYS)

#endif /* !CONFIG_HUGETLBFS */

#ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
					unsigned long len, unsigned long pgoff,
					unsigned long flags);
#endif /* HAVE_ARCH_HUGETLB_UNMAPPED_AREA */

#ifdef CONFIG_HUGETLB_PAGE

/* Defines one hugetlb page size */
struct hstate {
	int hugetlb_next_nid;
	unsigned int order;
	unsigned long mask;
	unsigned long max_huge_pages;
	unsigned long nr_huge_pages;
	unsigned long free_huge_pages;
	unsigned long resv_huge_pages;
	unsigned long surplus_huge_pages;
	unsigned long nr_overcommit_huge_pages;
	struct list_head hugepage_freelists[MAX_NUMNODES];
	unsigned int nr_huge_pages_node[MAX_NUMNODES];
	unsigned int free_huge_pages_node[MAX_NUMNODES];
	unsigned int surplus_huge_pages_node[MAX_NUMNODES];
};

void __init hugetlb_add_hstate(unsigned order);
struct hstate *size_to_hstate(unsigned long size);

#ifndef HUGE_MAX_HSTATE
#define HUGE_MAX_HSTATE 1
#endif

extern struct hstate hstates[HUGE_MAX_HSTATE];
extern unsigned int default_hstate_idx;

#define default_hstate (hstates[default_hstate_idx])

static inline struct hstate *hstate_vma(struct vm_area_struct *vma)
{
	return &default_hstate;
}

static inline struct hstate *hstate_file(struct file *f)
{
	return &default_hstate;
}

static inline struct hstate *hstate_inode(struct inode *i)
{
	return &default_hstate;
}

static inline unsigned long huge_page_size(struct hstate *h)
{
	return (unsigned long)PAGE_SIZE << h->order;
}

static inline unsigned long huge_page_mask(struct hstate *h)
{
	return h->mask;
}

static inline unsigned int huge_page_order(struct hstate *h)
{
	return h->order;
}

static inline unsigned huge_page_shift(struct hstate *h)
{
	return h->order + PAGE_SHIFT;
}

static inline unsigned int pages_per_huge_page(struct hstate *h)
{
	return 1 << h->order;
}

static inline unsigned int blocks_per_huge_page(struct hstate *h)
{
	return huge_page_size(h) / 512;
}

#include <asm/hugetlb.h>

static inline struct hstate *page_hstate(struct page *page)
{
	return size_to_hstate(PAGE_SIZE << compound_order(page));
}

#else
struct hstate {};
#define hstate_file(f) NULL
#define hstate_vma(v) NULL
#define hstate_inode(i) NULL
#define huge_page_size(h) PAGE_SIZE
#define huge_page_mask(h) PAGE_MASK
#define huge_page_order(h) 0
#define huge_page_shift(h) PAGE_SHIFT
#define pages_per_huge_page(h) 1
#endif

#endif /* _LINUX_HUGETLB_H */