[net-next-2.6.git] / fs / proc / page.c

#include <linux/bootmem.h>
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ksm.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/hugetlb.h>
#include <linux/kernel-page-flags.h>
#include <asm/uaccess.h>
#include "internal.h"

#define KPMSIZE sizeof(u64)
#define KPMMASK (KPMSIZE - 1)

/* /proc/kpagecount - an array exposing page counts
 *
 * Each entry is a u64 representing the corresponding
 * physical page count.
 */
static ssize_t kpagecount_read(struct file *file, char __user *buf,
			     size_t count, loff_t *ppos)
{
	u64 __user *out = (u64 __user *)buf;
	struct page *ppage;
	unsigned long src = *ppos;
	unsigned long pfn;
	ssize_t ret = 0;
	u64 pcount;

	pfn = src / KPMSIZE;
	count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
	if (src & KPMMASK || count & KPMMASK)
		return -EINVAL;

	while (count > 0) {
		if (pfn_valid(pfn))
			ppage = pfn_to_page(pfn);
		else
			ppage = NULL;
		if (!ppage)
			pcount = 0;
		else
			pcount = page_mapcount(ppage);

		if (put_user(pcount, out)) {
			ret = -EFAULT;
			break;
		}

		pfn++;
		out++;
		count -= KPMSIZE;
	}

	*ppos += (char __user *)out - buf;
	if (!ret)
		ret = (char __user *)out - buf;
	return ret;
}

static const struct file_operations proc_kpagecount_operations = {
	.llseek = mem_lseek,
	.read = kpagecount_read,
};

/* /proc/kpageflags - an array exposing page flags
 *
 * Each entry is a u64 representing the corresponding
 * physical page flags.
 */

static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
{
	return ((kflags >> kbit) & 1) << ubit;
}

u64 stable_page_flags(struct page *page)
{
	u64 k;
	u64 u;

	/*
	 * pseudo flag: KPF_NOPAGE
	 * it differentiates a memory hole from a page with no flags
	 */
	if (!page)
		return 1 << KPF_NOPAGE;

	k = page->flags;
	u = 0;

	/*
	 * pseudo flags for the well known (anonymous) memory mapped pages
	 *
	 * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
	 * simple test in page_mapped() is not enough.
	 */
	if (!PageSlab(page) && page_mapped(page))
		u |= 1 << KPF_MMAP;
	if (PageAnon(page))
		u |= 1 << KPF_ANON;
	if (PageKsm(page))
		u |= 1 << KPF_KSM;

	/*
	 * compound pages: export both head/tail info
	 * they together define a compound page's start/end pos and order
	 */
	if (PageHead(page))
		u |= 1 << KPF_COMPOUND_HEAD;
	if (PageTail(page))
		u |= 1 << KPF_COMPOUND_TAIL;
	if (PageHuge(page))
		u |= 1 << KPF_HUGE;

	u |= kpf_copy_bit(k, KPF_LOCKED,	PG_locked);

	/*
	 * Caveats on high order pages:
	 * PG_buddy will only be set on the head page; SLUB/SLQB do the same
	 * for PG_slab; SLOB won't set PG_slab at all on compound pages.
	 */
	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);
	u |= kpf_copy_bit(k, KPF_BUDDY,		PG_buddy);

	u |= kpf_copy_bit(k, KPF_ERROR,		PG_error);
	u |= kpf_copy_bit(k, KPF_DIRTY,		PG_dirty);
	u |= kpf_copy_bit(k, KPF_UPTODATE,	PG_uptodate);
	u |= kpf_copy_bit(k, KPF_WRITEBACK,	PG_writeback);

	u |= kpf_copy_bit(k, KPF_LRU,		PG_lru);
	u |= kpf_copy_bit(k, KPF_REFERENCED,	PG_referenced);
	u |= kpf_copy_bit(k, KPF_ACTIVE,	PG_active);
	u |= kpf_copy_bit(k, KPF_RECLAIM,	PG_reclaim);

	u |= kpf_copy_bit(k, KPF_SWAPCACHE,	PG_swapcache);
	u |= kpf_copy_bit(k, KPF_SWAPBACKED,	PG_swapbacked);

	u |= kpf_copy_bit(k, KPF_UNEVICTABLE,	PG_unevictable);
	u |= kpf_copy_bit(k, KPF_MLOCKED,	PG_mlocked);

#ifdef CONFIG_MEMORY_FAILURE
	u |= kpf_copy_bit(k, KPF_HWPOISON,	PG_hwpoison);
#endif

#ifdef CONFIG_ARCH_USES_PG_UNCACHED
	u |= kpf_copy_bit(k, KPF_UNCACHED,	PG_uncached);
#endif

	u |= kpf_copy_bit(k, KPF_RESERVED,	PG_reserved);
	u |= kpf_copy_bit(k, KPF_MAPPEDTODISK,	PG_mappedtodisk);
	u |= kpf_copy_bit(k, KPF_PRIVATE,	PG_private);
	u |= kpf_copy_bit(k, KPF_PRIVATE_2,	PG_private_2);
	u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE,	PG_owner_priv_1);
	u |= kpf_copy_bit(k, KPF_ARCH,		PG_arch_1);

	return u;
};

static ssize_t kpageflags_read(struct file *file, char __user *buf,
			     size_t count, loff_t *ppos)
{
	u64 __user *out = (u64 __user *)buf;
	struct page *ppage;
	unsigned long src = *ppos;
	unsigned long pfn;
	ssize_t ret = 0;

	pfn = src / KPMSIZE;
	count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
	if (src & KPMMASK || count & KPMMASK)
		return -EINVAL;

	while (count > 0) {
		if (pfn_valid(pfn))
			ppage = pfn_to_page(pfn);
		else
			ppage = NULL;

		if (put_user(stable_page_flags(ppage), out)) {
			ret = -EFAULT;
			break;
		}

		pfn++;
		out++;
		count -= KPMSIZE;
	}

	*ppos += (char __user *)out - buf;
	if (!ret)
		ret = (char __user *)out - buf;
	return ret;
}

static const struct file_operations proc_kpageflags_operations = {
	.llseek = mem_lseek,
	.read = kpageflags_read,
};

static int __init proc_page_init(void)
{
	proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
	proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
	return 0;
}
module_init(proc_page_init);
Commit	Line	Data
6d80e53f AD	1	#include <linux/bootmem.h>
	2	#include <linux/compiler.h>
	3	#include <linux/fs.h>
	4	#include <linux/init.h>
9a840895	5	#include <linux/ksm.h>
6d80e53f AD	6	#include <linux/mm.h>
	7	#include <linux/mmzone.h>
	8	#include <linux/proc_fs.h>
	9	#include <linux/seq_file.h>
20a0307c	10	#include <linux/hugetlb.h>
1a9b5b7f	11	#include <linux/kernel-page-flags.h>
6d80e53f AD	12	#include <asm/uaccess.h>
	13	#include "internal.h"
	14
	15	#define KPMSIZE sizeof(u64)
	16	#define KPMMASK (KPMSIZE - 1)
ed7ce0f1	17
6d80e53f AD	18	/* /proc/kpagecount - an array exposing page counts
	19	*
	20	* Each entry is a u64 representing the corresponding
	21	* physical page count.
	22	*/
	23	static ssize_t kpagecount_read(struct file file, char __user buf,
	24	size_t count, loff_t *ppos)
	25	{
	26	u64 __user out = (u64 __user )buf;
	27	struct page *ppage;
	28	unsigned long src = *ppos;
	29	unsigned long pfn;
	30	ssize_t ret = 0;
	31	u64 pcount;
	32
	33	pfn = src / KPMSIZE;
	34	count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
	35	if (src & KPMMASK \|\| count & KPMMASK)
	36	return -EINVAL;
	37
	38	while (count > 0) {
6d80e53f AD	39	if (pfn_valid(pfn))
6d80e53f AD	40	ppage = pfn_to_page(pfn);
ed7ce0f1 WF	41	else
ed7ce0f1 WF	42	ppage = NULL;
6d80e53f AD	43	if (!ppage)
	44	pcount = 0;
	45	else
	46	pcount = page_mapcount(ppage);
	47
ed7ce0f1	48	if (put_user(pcount, out)) {
6d80e53f AD	49	ret = -EFAULT;
	50	break;
	51	}
	52
ed7ce0f1 WF	53	pfn++;
ed7ce0f1 WF	54	out++;
6d80e53f AD	55	count -= KPMSIZE;
	56	}
	57
	58	ppos += (char __user )out - buf;
	59	if (!ret)
	60	ret = (char __user *)out - buf;
	61	return ret;
	62	}
	63
	64	static const struct file_operations proc_kpagecount_operations = {
	65	.llseek = mem_lseek,
	66	.read = kpagecount_read,
	67	};
	68
	69	/* /proc/kpageflags - an array exposing page flags
	70	*
	71	* Each entry is a u64 representing the corresponding
	72	* physical page flags.
	73	*/
	74
17797549 WF	75	static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
	76	{
	77	return ((kflags >> kbit) & 1) << ubit;
	78	}
	79
1a9b5b7f	80	u64 stable_page_flags(struct page *page)
17797549 WF	81	{
	82	u64 k;
	83	u64 u;
	84
	85	/*
	86	* pseudo flag: KPF_NOPAGE
	87	* it differentiates a memory hole from a page with no flags
	88	*/
	89	if (!page)
	90	return 1 << KPF_NOPAGE;
	91
	92	k = page->flags;
	93	u = 0;
	94
	95	/*
	96	* pseudo flags for the well known (anonymous) memory mapped pages
	97	*
	98	* Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
	99	* simple test in page_mapped() is not enough.
	100	*/
	101	if (!PageSlab(page) && page_mapped(page))
	102	u \|= 1 << KPF_MMAP;
	103	if (PageAnon(page))
	104	u \|= 1 << KPF_ANON;
9a840895 HD	105	if (PageKsm(page))
9a840895 HD	106	u \|= 1 << KPF_KSM;
17797549 WF	107
	108	/*
	109	* compound pages: export both head/tail info
	110	* they together define a compound page's start/end pos and order
	111	*/
	112	if (PageHead(page))
	113	u \|= 1 << KPF_COMPOUND_HEAD;
	114	if (PageTail(page))
	115	u \|= 1 << KPF_COMPOUND_TAIL;
	116	if (PageHuge(page))
	117	u \|= 1 << KPF_HUGE;
	118
	119	u \|= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
	120
	121	/*
	122	* Caveats on high order pages:
	123	* PG_buddy will only be set on the head page; SLUB/SLQB do the same
	124	* for PG_slab; SLOB won't set PG_slab at all on compound pages.
	125	*/
	126	u \|= kpf_copy_bit(k, KPF_SLAB, PG_slab);
	127	u \|= kpf_copy_bit(k, KPF_BUDDY, PG_buddy);
	128
	129	u \|= kpf_copy_bit(k, KPF_ERROR, PG_error);
	130	u \|= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
	131	u \|= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
	132	u \|= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
	133
	134	u \|= kpf_copy_bit(k, KPF_LRU, PG_lru);
	135	u \|= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
	136	u \|= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
	137	u \|= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
	138
	139	u \|= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
	140	u \|= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
	141
17797549 WF	142	u \|= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
17797549 WF	143	u \|= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
17797549	144
253fb02d WF	145	#ifdef CONFIG_MEMORY_FAILURE
	146	u \|= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
	147	#endif
	148
ed430fec	149	#ifdef CONFIG_ARCH_USES_PG_UNCACHED
17797549 WF	150	u \|= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
	151	#endif
	152
	153	u \|= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
	154	u \|= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
	155	u \|= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
	156	u \|= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
	157	u \|= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
	158	u \|= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
	159
	160	return u;
	161	};
6d80e53f AD	162
	163	static ssize_t kpageflags_read(struct file file, char __user buf,
	164	size_t count, loff_t *ppos)
	165	{
	166	u64 __user out = (u64 __user )buf;
	167	struct page *ppage;
	168	unsigned long src = *ppos;
	169	unsigned long pfn;
	170	ssize_t ret = 0;
6d80e53f AD	171
	172	pfn = src / KPMSIZE;
	173	count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
	174	if (src & KPMMASK \|\| count & KPMMASK)
	175	return -EINVAL;
	176
	177	while (count > 0) {
6d80e53f AD	178	if (pfn_valid(pfn))
6d80e53f AD	179	ppage = pfn_to_page(pfn);
ed7ce0f1 WF	180	else
ed7ce0f1 WF	181	ppage = NULL;
17797549	182
1a9b5b7f	183	if (put_user(stable_page_flags(ppage), out)) {
6d80e53f AD	184	ret = -EFAULT;
	185	break;
	186	}
	187
ed7ce0f1 WF	188	pfn++;
ed7ce0f1 WF	189	out++;
6d80e53f AD	190	count -= KPMSIZE;
	191	}
	192
	193	ppos += (char __user )out - buf;
	194	if (!ret)
	195	ret = (char __user *)out - buf;
	196	return ret;
	197	}
	198
	199	static const struct file_operations proc_kpageflags_operations = {
	200	.llseek = mem_lseek,
	201	.read = kpageflags_read,
	202	};
	203
	204	static int __init proc_page_init(void)
	205	{
	206	proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
	207	proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
	208	return 0;
	209	}
	210	module_init(proc_page_init);