#define KPF_BYTES	8

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

/* copied from kpageflags_read() */

enum { 
        KPF_LOCKED,             /*  0 */
        KPF_ERROR,              /*  1 */
        KPF_REFERENCED,         /*  2 */
        KPF_UPTODATE,           /*  3 */
        KPF_DIRTY,              /*  4 */
        KPF_LRU,                /*  5 */
        KPF_ACTIVE,             /*  6 */
        KPF_SLAB,               /*  7 */
        KPF_WRITEBACK,          /*  8 */
        KPF_RECLAIM,            /*  9 */
        KPF_BUDDY,              /* 10 */
        KPF_MMAP,               /* 11 */
        KPF_SWAPCACHE,          /* 12 */
        KPF_SWAPBACKED,         /* 13 */
        KPF_MAPPEDTODISK,       /* 14 */
        KPF_RESERVED,           /* 15 */
        KPF_PRIVATE,            /* 16 */
        KPF_PRIVATE2,           /* 17 */
        KPF_OWNER_PRIVATE,      /* 18 */
        KPF_COMPOUND_HEAD,      /* 19 */
        KPF_COMPOUND_TAIL,      /* 20 */
        KPF_UNEVICTABLE,        /* 21 */
        KPF_MLOCKED,            /* 22 */
        KPF_POISON,             /* 23 */
        KPF_NOPAGE,             /* 24 */
        KPF_NUM
};

static char *page_flag_names[] = {
	[KPF_LOCKED]		= "L:locked",
	[KPF_ERROR]		= "E:error",
	[KPF_REFERENCED]	= "R:referenced",
	[KPF_UPTODATE]		= "U:uptodate",
	[KPF_DIRTY]		= "D:dirty",
	[KPF_LRU]		= "l:lru",
	[KPF_ACTIVE]		= "A:active",
	[KPF_SLAB]		= "S:slab",
	[KPF_WRITEBACK]		= "W:writeback",
	[KPF_RECLAIM]		= "x:reclaim",
	[KPF_BUDDY]		= "B:buddy",
	[KPF_RESERVED]		= "r:reserved",
	[KPF_SWAPCACHE]		= "c:swapcache",
	[KPF_SWAPBACKED]	= "b:swapbacked",
	[KPF_MAPPEDTODISK]	= "d:mappedtodisk",
	[KPF_PRIVATE]		= "P:private",
	[KPF_PRIVATE2]		= "p:private_2",
	[KPF_OWNER_PRIVATE]	= "O:owner_private",
	[KPF_COMPOUND_HEAD]	= "H:head",
	[KPF_COMPOUND_TAIL]	= "T:tail",
	[KPF_UNEVICTABLE]	= "u:unevictable",
	[KPF_MLOCKED]		= "M:mlocked",
	[KPF_MMAP]		= "m:mmap",
	[KPF_POISON]		= "X:poison",
	[KPF_NOPAGE]		= "n:nopage",
};

static unsigned long page_count[(1 << KPF_NUM)];
static unsigned long nr_pages;
static uint64_t kpageflags[KPF_BYTES * (16<<20)]; /* 64GB */

char *page_flag_name(uint64_t flags)
{
	int i;
	static char buf[64];

	for (i = 0; i < ARRAY_SIZE(page_flag_names); i++)
		buf[i] = (flags & (1 << i)) ? page_flag_names[i][0] : '_';

	return buf;
}

char *page_flag_longname(uint64_t flags)
{
	int i, n;
	static char buf[1024];

	for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++)
		if (flags & (1<<i))
		       n += snprintf(buf + n, sizeof(buf) - n, "%s,",
				       page_flag_names[i] + 2);
	if (n)
		n--;
	buf[n] = '\0';

	return buf;
}

static unsigned long pages2kb(unsigned long pages)
{
	return (pages * getpagesize()) >> 10;
}

static unsigned long pages2mb(unsigned long pages)
{
	return (pages * getpagesize()) >> 20;
}