[linux-2.6-block.git] / mm / pagewalk.c

#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/sched.h>

static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
			  const struct mm_walk *walk, void *private)
{
	pte_t *pte;
	int err = 0;

	pte = pte_offset_map(pmd, addr);
	for (;;) {
		err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
		if (err)
		       break;
		addr += PAGE_SIZE;
		if (addr == end)
			break;
		pte++;
	}

	pte_unmap(pte);
	return err;
}

static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
			  const struct mm_walk *walk, void *private)
{
	pmd_t *pmd;
	unsigned long next;
	int err = 0;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		if (pmd_none_or_clear_bad(pmd)) {
			if (walk->pte_hole)
				err = walk->pte_hole(addr, next, private);
			if (err)
				break;
			continue;
		}
		if (walk->pmd_entry)
			err = walk->pmd_entry(pmd, addr, next, private);
		if (!err && walk->pte_entry)
			err = walk_pte_range(pmd, addr, next, walk, private);
		if (err)
			break;
	} while (pmd++, addr = next, addr != end);

	return err;
}

static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
			  const struct mm_walk *walk, void *private)
{
	pud_t *pud;
	unsigned long next;
	int err = 0;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
		if (pud_none_or_clear_bad(pud)) {
			if (walk->pte_hole)
				err = walk->pte_hole(addr, next, private);
			if (err)
				break;
			continue;
		}
		if (walk->pud_entry)
			err = walk->pud_entry(pud, addr, next, private);
		if (!err && (walk->pmd_entry || walk->pte_entry))
			err = walk_pmd_range(pud, addr, next, walk, private);
		if (err)
			break;
	} while (pud++, addr = next, addr != end);

	return err;
}

/**
 * walk_page_range - walk a memory map's page tables with a callback
 * @mm: memory map to walk
 * @addr: starting address
 * @end: ending address
 * @walk: set of callbacks to invoke for each level of the tree
 * @private: private data passed to the callback function
 *
 * Recursively walk the page table for the memory area in a VMA,
 * calling supplied callbacks. Callbacks are called in-order (first
 * PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
 * etc.). If lower-level callbacks are omitted, walking depth is reduced.
 *
 * Each callback receives an entry pointer, the start and end of the
 * associated range, and a caller-supplied private data pointer.
 *
 * No locks are taken, but the bottom level iterator will map PTE
 * directories from highmem if necessary.
 *
 * If any callback returns a non-zero value, the walk is aborted and
 * the return value is propagated back to the caller. Otherwise 0 is returned.
 */
int walk_page_range(const struct mm_struct *mm,
		    unsigned long addr, unsigned long end,
		    const struct mm_walk *walk, void *private)
{
	pgd_t *pgd;
	unsigned long next;
	int err = 0;

	if (addr >= end)
		return err;

	pgd = pgd_offset(mm, addr);
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd)) {
			if (walk->pte_hole)
				err = walk->pte_hole(addr, next, private);
			if (err)
				break;
			continue;
		}
		if (walk->pgd_entry)
			err = walk->pgd_entry(pgd, addr, next, private);
		if (!err &&
		    (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
			err = walk_pud_range(pgd, addr, next, walk, private);
		if (err)
			break;
	} while (pgd++, addr = next, addr != end);

	return err;
}
Commit	Line	Data
e6473092 MM	1	#include <linux/mm.h>
	2	#include <linux/highmem.h>
	3	#include <linux/sched.h>
	4
	5	static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
	6	const struct mm_walk walk, void private)
	7	{
	8	pte_t *pte;
	9	int err = 0;
	10
	11	pte = pte_offset_map(pmd, addr);
556637cd	12	for (;;) {
e6473092 MM	13	err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
	14	if (err)
	15	break;
556637cd JW	16	addr += PAGE_SIZE;
	17	if (addr == end)
	18	break;
	19	pte++;
	20	}
e6473092 MM	21
	22	pte_unmap(pte);
	23	return err;
	24	}
	25
	26	static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
	27	const struct mm_walk walk, void private)
	28	{
	29	pmd_t *pmd;
	30	unsigned long next;
	31	int err = 0;
	32
	33	pmd = pmd_offset(pud, addr);
	34	do {
	35	next = pmd_addr_end(addr, end);
	36	if (pmd_none_or_clear_bad(pmd)) {
	37	if (walk->pte_hole)
	38	err = walk->pte_hole(addr, next, private);
	39	if (err)
	40	break;
	41	continue;
	42	}
	43	if (walk->pmd_entry)
	44	err = walk->pmd_entry(pmd, addr, next, private);
	45	if (!err && walk->pte_entry)
	46	err = walk_pte_range(pmd, addr, next, walk, private);
	47	if (err)
	48	break;
	49	} while (pmd++, addr = next, addr != end);
	50
	51	return err;
	52	}
	53
	54	static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
	55	const struct mm_walk walk, void private)
	56	{
	57	pud_t *pud;
	58	unsigned long next;
	59	int err = 0;
	60
	61	pud = pud_offset(pgd, addr);
	62	do {
	63	next = pud_addr_end(addr, end);
	64	if (pud_none_or_clear_bad(pud)) {
	65	if (walk->pte_hole)
	66	err = walk->pte_hole(addr, next, private);
	67	if (err)
	68	break;
	69	continue;
	70	}
	71	if (walk->pud_entry)
	72	err = walk->pud_entry(pud, addr, next, private);
	73	if (!err && (walk->pmd_entry \|\| walk->pte_entry))
	74	err = walk_pmd_range(pud, addr, next, walk, private);
	75	if (err)
	76	break;
	77	} while (pud++, addr = next, addr != end);
	78
	79	return err;
	80	}
	81
	82	/**
	83	* walk_page_range - walk a memory map's page tables with a callback
7682486b RD	84	* @mm: memory map to walk
	85	* @addr: starting address
	86	* @end: ending address
	87	* @walk: set of callbacks to invoke for each level of the tree
	88	* @private: private data passed to the callback function
e6473092 MM	89	*
	90	* Recursively walk the page table for the memory area in a VMA,
	91	* calling supplied callbacks. Callbacks are called in-order (first
	92	* PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
	93	* etc.). If lower-level callbacks are omitted, walking depth is reduced.
	94	*
	95	* Each callback receives an entry pointer, the start and end of the
	96	* associated range, and a caller-supplied private data pointer.
	97	*
	98	* No locks are taken, but the bottom level iterator will map PTE
	99	* directories from highmem if necessary.
	100	*
	101	* If any callback returns a non-zero value, the walk is aborted and
	102	* the return value is propagated back to the caller. Otherwise 0 is returned.
	103	*/
	104	int walk_page_range(const struct mm_struct *mm,
	105	unsigned long addr, unsigned long end,
	106	const struct mm_walk walk, void private)
	107	{
	108	pgd_t *pgd;
	109	unsigned long next;
	110	int err = 0;
	111
	112	if (addr >= end)
	113	return err;
	114
	115	pgd = pgd_offset(mm, addr);
	116	do {
	117	next = pgd_addr_end(addr, end);
	118	if (pgd_none_or_clear_bad(pgd)) {
	119	if (walk->pte_hole)
	120	err = walk->pte_hole(addr, next, private);
	121	if (err)
	122	break;
	123	continue;
	124	}
	125	if (walk->pgd_entry)
	126	err = walk->pgd_entry(pgd, addr, next, private);
	127	if (!err &&
	128	(walk->pud_entry \|\| walk->pmd_entry \|\| walk->pte_entry))
	129	err = walk_pud_range(pgd, addr, next, walk, private);
	130	if (err)
	131	break;
	132	} while (pgd++, addr = next, addr != end);
	133
	134	return err;
	135	}