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File: [Development] / linux-2.6-xfs / lib / genalloc.c (download)

Revision 1.6, Wed Sep 12 17:09:56 2007 UTC (10 years, 1 month ago) by tes.longdrop.melbourne.sgi.com
Branch: MAIN
CVS Tags: HEAD
Changes since 1.5: +1 -2 lines

Update 2.6.x-xfs to 2.6.23-rc4.

Also update fs/xfs with external mainline changes.
There were 12 such missing commits that I detected:

--------
commit ad690ef9e690f6c31f7d310b09ef1314bcec9033
Author: Al Viro <viro@ftp.linux.org.uk>
    xfs ioctl __user annotations

commit 20c2df83d25c6a95affe6157a4c9cac4cf5ffaac
Author: Paul Mundt <lethal@linux-sh.org>
    mm: Remove slab destructors from kmem_cache_create().

commit d0217ac04ca6591841e5665f518e38064f4e65bd
Author: Nick Piggin <npiggin@suse.de>
    mm: fault feedback #1

commit 54cb8821de07f2ffcd28c380ce9b93d5784b40d7
Author: Nick Piggin <npiggin@suse.de>
    mm: merge populate and nopage into fault (fixes nonlinear)

commit d00806b183152af6d24f46f0c33f14162ca1262a
Author: Nick Piggin <npiggin@suse.de>
    mm: fix fault vs invalidate race for linear mappings

commit a569425512253992cc64ebf8b6d00a62f986db3e
Author: Christoph Hellwig <hch@infradead.org>
    knfsd: exportfs: add exportfs.h header

commit 831441862956fffa17b9801db37e6ea1650b0f69
Author: Rafael J. Wysocki <rjw@sisk.pl>
    Freezer: make kernel threads nonfreezable by default

commit 8e1f936b73150f5095448a0fee6d4f30a1f9001d
Author: Rusty Russell <rusty@rustcorp.com.au>
    mm: clean up and kernelify shrinker registration

commit 5ffc4ef45b3b0a57872f631b4e4ceb8ace0d7496
Author: Jens Axboe <jens.axboe@oracle.com>
    sendfile: remove .sendfile from filesystems that use generic_file_sendfile()

commit 8bb7844286fb8c9fce6f65d8288aeb09d03a5e0d
Author: Rafael J. Wysocki <rjw@sisk.pl>
    Add suspend-related notifications for CPU hotplug

commit 59c51591a0ac7568824f541f57de967e88adaa07
Author: Michael Opdenacker <michael@free-electrons.com>
    Fix occurrences of "the the "

commit 0ceb331433e8aad9c5f441a965d7c681f8b9046f
Author: Dmitriy Monakhov <dmonakhov@openvz.org>
    mm: move common segment checks to separate helper function
--------
Merge of 2.6.x-xfs-melb:linux:29656b by kenmcd.

/*
 * Basic general purpose allocator for managing special purpose memory
 * not managed by the regular kmalloc/kfree interface.
 * Uses for this includes on-device special memory, uncached memory
 * etc.
 *
 * Copyright 2005 (C) Jes Sorensen <jes@trained-monkey.org>
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2.  See the file COPYING for more details.
 */

#include <linux/module.h>
#include <linux/genalloc.h>


/**
 * gen_pool_create - create a new special memory pool
 * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
 * @nid: node id of the node the pool structure should be allocated on, or -1
 *
 * Create a new special memory pool that can be used to manage special purpose
 * memory not managed by the regular kmalloc/kfree interface.
 */
struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
{
	struct gen_pool *pool;

	pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
	if (pool != NULL) {
		rwlock_init(&pool->lock);
		INIT_LIST_HEAD(&pool->chunks);
		pool->min_alloc_order = min_alloc_order;
	}
	return pool;
}
EXPORT_SYMBOL(gen_pool_create);

/**
 * gen_pool_add - add a new chunk of special memory to the pool
 * @pool: pool to add new memory chunk to
 * @addr: starting address of memory chunk to add to pool
 * @size: size in bytes of the memory chunk to add to pool
 * @nid: node id of the node the chunk structure and bitmap should be
 *       allocated on, or -1
 *
 * Add a new chunk of special memory to the specified pool.
 */
int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
		 int nid)
{
	struct gen_pool_chunk *chunk;
	int nbits = size >> pool->min_alloc_order;
	int nbytes = sizeof(struct gen_pool_chunk) +
				(nbits + BITS_PER_BYTE - 1) / BITS_PER_BYTE;

	chunk = kmalloc_node(nbytes, GFP_KERNEL | __GFP_ZERO, nid);
	if (unlikely(chunk == NULL))
		return -1;

	spin_lock_init(&chunk->lock);
	chunk->start_addr = addr;
	chunk->end_addr = addr + size;

	write_lock(&pool->lock);
	list_add(&chunk->next_chunk, &pool->chunks);
	write_unlock(&pool->lock);

	return 0;
}
EXPORT_SYMBOL(gen_pool_add);

/**
 * gen_pool_destroy - destroy a special memory pool
 * @pool: pool to destroy
 *
 * Destroy the specified special memory pool. Verifies that there are no
 * outstanding allocations.
 */
void gen_pool_destroy(struct gen_pool *pool)
{
	struct list_head *_chunk, *_next_chunk;
	struct gen_pool_chunk *chunk;
	int order = pool->min_alloc_order;
	int bit, end_bit;


	write_lock(&pool->lock);
	list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
		chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
		list_del(&chunk->next_chunk);

		end_bit = (chunk->end_addr - chunk->start_addr) >> order;
		bit = find_next_bit(chunk->bits, end_bit, 0);
		BUG_ON(bit < end_bit);

		kfree(chunk);
	}
	kfree(pool);
	return;
}
EXPORT_SYMBOL(gen_pool_destroy);

/**
 * gen_pool_alloc - allocate special memory from the pool
 * @pool: pool to allocate from
 * @size: number of bytes to allocate from the pool
 *
 * Allocate the requested number of bytes from the specified pool.
 * Uses a first-fit algorithm.
 */
unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
{
	struct list_head *_chunk;
	struct gen_pool_chunk *chunk;
	unsigned long addr, flags;
	int order = pool->min_alloc_order;
	int nbits, bit, start_bit, end_bit;

	if (size == 0)
		return 0;

	nbits = (size + (1UL << order) - 1) >> order;

	read_lock(&pool->lock);
	list_for_each(_chunk, &pool->chunks) {
		chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);

		end_bit = (chunk->end_addr - chunk->start_addr) >> order;
		end_bit -= nbits + 1;

		spin_lock_irqsave(&chunk->lock, flags);
		bit = -1;
		while (bit + 1 < end_bit) {
			bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
			if (bit >= end_bit)
				break;

			start_bit = bit;
			if (nbits > 1) {
				bit = find_next_bit(chunk->bits, bit + nbits,
							bit + 1);
				if (bit - start_bit < nbits)
					continue;
			}

			addr = chunk->start_addr +
					    ((unsigned long)start_bit << order);
			while (nbits--)
				__set_bit(start_bit++, chunk->bits);
			spin_unlock_irqrestore(&chunk->lock, flags);
			read_unlock(&pool->lock);
			return addr;
		}
		spin_unlock_irqrestore(&chunk->lock, flags);
	}
	read_unlock(&pool->lock);
	return 0;
}
EXPORT_SYMBOL(gen_pool_alloc);

/**
 * gen_pool_free - free allocated special memory back to the pool
 * @pool: pool to free to
 * @addr: starting address of memory to free back to pool
 * @size: size in bytes of memory to free
 *
 * Free previously allocated special memory back to the specified pool.
 */
void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
{
	struct list_head *_chunk;
	struct gen_pool_chunk *chunk;
	unsigned long flags;
	int order = pool->min_alloc_order;
	int bit, nbits;

	nbits = (size + (1UL << order) - 1) >> order;

	read_lock(&pool->lock);
	list_for_each(_chunk, &pool->chunks) {
		chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);

		if (addr >= chunk->start_addr && addr < chunk->end_addr) {
			BUG_ON(addr + size > chunk->end_addr);
			spin_lock_irqsave(&chunk->lock, flags);
			bit = (addr - chunk->start_addr) >> order;
			while (nbits--)
				__clear_bit(bit++, chunk->bits);
			spin_unlock_irqrestore(&chunk->lock, flags);
			break;
		}
	}
	BUG_ON(nbits > 0);
	read_unlock(&pool->lock);
}
EXPORT_SYMBOL(gen_pool_free);