[net-next-2.6.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,
			  struct mm_walk *walk)
{
	pte_t *pte;
	int err = 0;

	pte = pte_offset_map(pmd, addr);
	for (;;) {
		err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
		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,
			  struct mm_walk *walk)
{
	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, walk);
			if (err)
				break;
			continue;
		}
		if (walk->pmd_entry)
			err = walk->pmd_entry(pmd, addr, next, walk);
		if (!err && walk->pte_entry)
			err = walk_pte_range(pmd, addr, next, walk);
		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,
			  struct mm_walk *walk)
{
	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, walk);
			if (err)
				break;
			continue;
		}
		if (walk->pud_entry)
			err = walk->pud_entry(pud, addr, next, walk);
		if (!err && (walk->pmd_entry || walk->pte_entry))
			err = walk_pmd_range(pud, addr, next, walk);
		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
 *
 * 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 and the start and end of the
 * associated range, and a copy of the original mm_walk for access to
 * the ->private or ->mm fields.
 *
 * 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(unsigned long addr, unsigned long end,
		    struct mm_walk *walk)
{
	pgd_t *pgd;
	unsigned long next;
	int err = 0;

	if (addr >= end)
		return err;

	if (!walk->mm)
		return -EINVAL;

	pgd = pgd_offset(walk->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, walk);
			if (err)
				break;
			continue;
		}
		if (walk->pgd_entry)
			err = walk->pgd_entry(pgd, addr, next, walk);
		if (!err &&
		    (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
			err = walk_pud_range(pgd, addr, next, walk);
		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,
2165009b	6	struct mm_walk *walk)
e6473092 MM	7	{
	8	pte_t *pte;
	9	int err = 0;
	10
	11	pte = pte_offset_map(pmd, addr);
556637cd	12	for (;;) {
2165009b	13	err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
e6473092 MM	14	if (err)
e6473092 MM	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,
2165009b	27	struct mm_walk *walk)
e6473092 MM	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)
2165009b	38	err = walk->pte_hole(addr, next, walk);
e6473092 MM	39	if (err)
	40	break;
	41	continue;
	42	}
	43	if (walk->pmd_entry)
2165009b	44	err = walk->pmd_entry(pmd, addr, next, walk);
e6473092	45	if (!err && walk->pte_entry)
2165009b	46	err = walk_pte_range(pmd, addr, next, walk);
e6473092 MM	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,
2165009b	55	struct mm_walk *walk)
e6473092 MM	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)
2165009b	66	err = walk->pte_hole(addr, next, walk);
e6473092 MM	67	if (err)
	68	break;
	69	continue;
	70	}
	71	if (walk->pud_entry)
2165009b	72	err = walk->pud_entry(pud, addr, next, walk);
e6473092	73	if (!err && (walk->pmd_entry \|\| walk->pte_entry))
2165009b	74	err = walk_pmd_range(pud, addr, next, walk);
e6473092 MM	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
e6473092 MM	88	*
	89	* Recursively walk the page table for the memory area in a VMA,
	90	* calling supplied callbacks. Callbacks are called in-order (first
	91	* PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
	92	* etc.). If lower-level callbacks are omitted, walking depth is reduced.
	93	*
2165009b DH	94	* Each callback receives an entry pointer and the start and end of the
	95	* associated range, and a copy of the original mm_walk for access to
	96	* the ->private or ->mm fields.
e6473092 MM	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	*/
2165009b DH	104	int walk_page_range(unsigned long addr, unsigned long end,
2165009b DH	105	struct mm_walk *walk)
e6473092 MM	106	{
	107	pgd_t *pgd;
	108	unsigned long next;
	109	int err = 0;
	110
	111	if (addr >= end)
	112	return err;
	113
2165009b DH	114	if (!walk->mm)
	115	return -EINVAL;
	116
	117	pgd = pgd_offset(walk->mm, addr);
e6473092 MM	118	do {
	119	next = pgd_addr_end(addr, end);
	120	if (pgd_none_or_clear_bad(pgd)) {
	121	if (walk->pte_hole)
2165009b	122	err = walk->pte_hole(addr, next, walk);
e6473092 MM	123	if (err)
	124	break;
	125	continue;
	126	}
	127	if (walk->pgd_entry)
2165009b	128	err = walk->pgd_entry(pgd, addr, next, walk);
e6473092 MM	129	if (!err &&
e6473092 MM	130	(walk->pud_entry \|\| walk->pmd_entry \|\| walk->pte_entry))
2165009b	131	err = walk_pud_range(pgd, addr, next, walk);
e6473092 MM	132	if (err)
	133	break;
	134	} while (pgd++, addr = next, addr != end);
	135
	136	return err;
	137	}