/*
 * mm/percpu-km.c - kernel memory based chunk allocation
 *
 * Copyright (C) 2010		SUSE Linux Products GmbH
 * Copyright (C) 2010		Tejun Heo <tj@kernel.org>
 *
 * This file is released under the GPLv2.
 *
 * Chunks are allocated as a contiguous kernel memory using gfp
 * allocation.  This is to be used on nommu architectures.
 *
 * To use percpu-km,
 *
 * - define CONFIG_NEED_PER_CPU_KM from the arch Kconfig.
 *
 * - CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK must not be defined.  It's
 *   not compatible with PER_CPU_KM.  EMBED_FIRST_CHUNK should work
 *   fine.
 *
 * - NUMA is not supported.  When setting up the first chunk,
 *   @cpu_distance_fn should be NULL or report all CPUs to be nearer
 *   than or at LOCAL_DISTANCE.
 *
 * - It's best if the chunk size is power of two multiple of
 *   PAGE_SIZE.  Because each chunk is allocated as a contiguous
 *   kernel memory block using alloc_pages(), memory will be wasted if
 *   chunk size is not aligned.  percpu-km code will whine about it.
 */

#if defined(CONFIG_SMP) && defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)
#error "contiguous percpu allocation is incompatible with paged first chunk"
#endif

#include <linux/log2.h>

static int pcpu_populate_chunk(struct pcpu_chunk *chunk,
			       int page_start, int page_end)
{
	return 0;
}

static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk,
				  int page_start, int page_end)
{
	/* nada */
}

static struct pcpu_chunk *pcpu_create_chunk(void)
{
	const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;
	struct pcpu_chunk *chunk;
	struct page *pages;
	int i;

	chunk = pcpu_alloc_chunk();
	if (!chunk)
		return NULL;

	pages = alloc_pages(GFP_KERNEL, order_base_2(nr_pages));
	if (!pages) {
		pcpu_free_chunk(chunk);
		return NULL;
	}

	for (i = 0; i < nr_pages; i++)
		pcpu_set_page_chunk(nth_page(pages, i), chunk);

	chunk->data = pages;
	chunk->base_addr = page_address(pages) - pcpu_group_offsets[0];

	spin_lock_irq(&pcpu_lock);
	pcpu_chunk_populated(chunk, 0, nr_pages);
	spin_unlock_irq(&pcpu_lock);

	return chunk;
}

static void pcpu_destroy_chunk(struct pcpu_chunk *chunk)
{
	const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT;

	if (chunk && chunk->data)
		__free_pages(chunk->data, order_base_2(nr_pages));
	pcpu_free_chunk(chunk);
}

static struct page *pcpu_addr_to_page(void *addr)
{
	return virt_to_page(addr);
}

static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai)
{
	size_t nr_pages, alloc_pages;

	/* all units must be in a single group */
	if (ai->nr_groups != 1) {
		pr_crit("can't handle more than one group\n");
		return -EINVAL;
	}

	nr_pages = (ai->groups[0].nr_units * ai->unit_size) >> PAGE_SHIFT;
	alloc_pages = roundup_pow_of_two(nr_pages);

	if (alloc_pages > nr_pages)
		pr_warn("wasting %zu pages per chunk\n",
			alloc_pages - nr_pages);

	return 0;
}
 href='/cgit.cgi/linux/net-next.git/log/?h=nds-private-remove&amp;id=473153291b8a131c86787fd9b076a529573e2c19'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/include?h=nds-private-remove&amp;id=473153291b8a131c86787fd9b076a529573e2c19'>include</a>/<a href='/cgit.cgi/linux/net-next.git/log/include/xen?h=nds-private-remove&amp;id=473153291b8a131c86787fd9b076a529573e2c19'>xen</a>/<a href='/cgit.cgi/linux/net-next.git/log/include/xen/xen.h?h=nds-private-remove&amp;id=473153291b8a131c86787fd9b076a529573e2c19'>xen.h</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/include/xen/xen.h?h=nds-private-remove&amp;id=473153291b8a131c86787fd9b076a529573e2c19&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
ion><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-15 16:09:50 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-15 16:09:50 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bridge/br_forward.c?id=99421c1cb27fb837e93b517036fab4500fe39de5'>99421c1cb27fb837e93b517036fab4500fe39de5</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/bridge/br_forward.c?id=99421c1cb27fb837e93b517036fab4500fe39de5'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=99421c1cb27fb837e93b517036fab4500fe39de5'>de5fc5bacb671223f389793ad643cebe520bc292</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/bridge/br_forward.c?id=99421c1cb27fb837e93b517036fab4500fe39de5'>net/bridge/br_forward.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bridge/br_forward.c?id=c92816275674c1491ce228ee49aa030a5fa1be04'>c92816275674c1491ce228ee49aa030a5fa1be04</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/bridge/br_forward.c?id=99421c1cb27fb837e93b517036fab4500fe39de5&amp;id2=c92816275674c1491ce228ee49aa030a5fa1be04'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bridge/br_forward.c?id=93362fa47fe98b62e4a34ab408c4a418432e7939'>93362fa47fe98b62e4a34ab408c4a418432e7939</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/bridge/br_forward.c?id=99421c1cb27fb837e93b517036fab4500fe39de5&amp;id2=93362fa47fe98b62e4a34ab408c4a418432e7939'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace</div><div class='commit-msg'>Pull namespace fixes from Eric Biederman:
 "This tree contains 4 fixes.

  The first is a fix for a race that can causes oopses under the right
  circumstances, and that someone just recently encountered.

  Past that are several small trivial correct fixes. A real issue that
  was blocking development of an out of tree driver, but does not appear
  to have caused any actual problems for in-tree code. A potential
  deadlock that was reported by lockdep. And a deadlock people have
  experienced and took the time to track down caused by a cleanup that
  removed the code to drop a reference count"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sysctl: Drop reference added by grab_header in proc_sys_readdir
  pid: fix lockdep deadlock warning due to ucount_lock
  libfs: Modify mount_pseudo_xattr to be clear it is not a userspace mount
  mnt: Protect the mountpoint hashtable with mount_lock
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=99421c1cb27fb837e93b517036fab4500fe39de5'>Diffstat</a> (limited to 'net/bridge/br_forward.c')</div><table summary='diffstat' class='diffstat'>