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path: root/crypto/ablkcipher.c

Age	Commit message (Expand)	Author
2016-07-18	crypto: skcipher - Remove top-level givcipher interface	Herbert Xu
2016-06-07	crypto: skcipher - remove unused header cpumask.h	Geliang Tang
2015-12-09	crypto: skcipher - Copy iv from desc even for 0-len walks	Jason A. Donenfeld
2015-10-20	crypto: api - Only abort operations on fatal signal	Herbert Xu
2015-06-22	crypto: skcipher - Allow givencrypt to be NULL	Herbert Xu
2015-05-25	crypto: skcipher - Use tmpl->create	Herbert Xu
2015-04-26	crypto: skcipher - Fix corner case in crypto_lookup_skcipher	Herbert Xu
2015-01-26	crypto: replace scatterwalk_sg_next with sg_next	Cristian Stoica
2014-12-22	crypto: ablkcipher - fixed style errors in ablkcipher.c	Joshua I. James
2013-10-30	crypto: skcipher - Use eseqiv even on UP machines	Herbert Xu
2013-02-19	crypto: user - fix info leaks in report API	Mathias Krause
2012-04-10	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	David S. Miller
2012-04-02	crypto: Stop using NLA_PUT*().	David S. Miller
2012-03-29	crypto: user - Fix lookup of algorithms with IV generator	Steffen Klassert
2011-11-11	crypto: algapi - Fix build problem with NET disabled	Herbert Xu
2011-10-21	crypto: Add userspace report for givcipher type algorithms	Steffen Klassert
2011-10-21	crypto: Add userspace report for ablkcipher type algorithms	Steffen Klassert
2011-01-29	crypto: skcipher - remove redundant NULL check	Davidlohr Bueso
2010-06-23	crypto: skcipher - avoid NULL dereference	Jiri Slaby
2010-05-19	crypto: skcipher - Add ablkcipher_walk interfaces	David S. Miller
2010-02-16	crypto: ablkcipher - Fix checkpatch errors	Richard Hartmann
2009-08-14	crypto: blkcipher - Do not use eseqiv on stream ciphers	Herbert Xu
2009-06-25	crypto: skcipher - Change default sync geniv on SMP to eseqiv	Herbert Xu
2009-06-25	crypto: skcipher - Fix request for sync algorithms	Herbert Xu
2009-02-18	crypto: skcipher - Avoid infinite loop when cipher fails selftest	Herbert Xu
2008-02-23	[CRYPTO] skcipher: Move chainiv/seqiv into crypto_blkcipher module	Herbert Xu
2008-01-11	[CRYPTO] api: Show async type	Herbert Xu
2008-01-11	[CRYPTO] skcipher: Create default givcipher instances	Herbert Xu
2008-01-11	[CRYPTO] skcipher: Add skcipher_geniv_alloc/skcipher_geniv_free	Herbert Xu
2008-01-11	[CRYPTO] skcipher: Added geniv field	Herbert Xu
2008-01-11	[CRYPTO] skcipher: Add givcrypt operations and givcipher type	Herbert Xu
2008-01-11	[CRYPTO] skcipher: Add crypto_grab_skcipher interface	Herbert Xu
2007-10-10	[CRYPTO] ablkcipher: Remove queue pointer from common alg object	Herbert Xu
2007-10-10	[CRYPTO] api: Add missing headers for setkey_unaligned	Herbert Xu
2007-08-06	[CRYPTO] api: fix writting into unallocated memory in setkey_aligned	Sebastian Siewior
2007-07-11	[CRYPTO] api: Allow ablkcipher with no queues	Sebastian Siewior
2007-07-11	[CRYPTO] api: Handle unaligned keys in setkey	Sebastian Siewior
2007-05-02	[CRYPTO] api: Add async blkcipher type	Herbert Xu

generated by cgit v1.2.3 (git 2.25.1) at 2024-09-09 20:55:10 +0000

// SPDX-License-Identifier: GPL-2.0
/*
 * Manage cache of swap slots to be used for and returned from
 * swap.
 *
 * Copyright(c) 2016 Intel Corporation.
 *
 * Author: Tim Chen <tim.c.chen@linux.intel.com>
 *
 * We allocate the swap slots from the global pool and put
 * it into local per cpu caches.  This has the advantage
 * of no needing to acquire the swap_info lock every time
 * we need a new slot.
 *
 * There is also opportunity to simply return the slot
 * to local caches without needing to acquire swap_info
 * lock.  We do not reuse the returned slots directly but
 * move them back to the global pool in a batch.  This
 * allows the slots to coaellesce and reduce fragmentation.
 *
 * The swap entry allocated is marked with SWAP_HAS_CACHE
 * flag in map_count that prevents it from being allocated
 * again from the global pool.
 *
 * The swap slots cache is protected by a mutex instead of
 * a spin lock as when we search for slots with scan_swap_map,
 * we can possibly sleep.
 */

#include <linux/swap_slots.h>
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/vmalloc.h>
#include <linux/mutex.h>
#include <linux/mm.h>

static DEFINE_PER_CPU(struct swap_slots_cache, swp_slots);
static bool	swap_slot_cache_active;
bool	swap_slot_cache_enabled;
static bool	swap_slot_cache_initialized;
static DEFINE_MUTEX(swap_slots_cache_mutex);
/* Serialize swap slots cache enable/disable operations */
static DEFINE_MUTEX(swap_slots_cache_enable_mutex);

static void __drain_swap_slots_cache(unsigned int type);
static void deactivate_swap_slots_cache(void);
static void reactivate_swap_slots_cache(void);

#define use_swap_slot_cache (swap_slot_cache_active && \
		swap_slot_cache_enabled && swap_slot_cache_initialized)
#define SLOTS_CACHE 0x1
#define SLOTS_CACHE_RET 0x2

static void deactivate_swap_slots_cache(void)
{
	mutex_lock(&swap_slots_cache_mutex);
	swap_slot_cache_active = false;
	__drain_swap_slots_cache(SLOTS_CACHE|SLOTS_CACHE_RET);
	mutex_unlock(&swap_slots_cache_mutex);
}

static void reactivate_swap_slots_cache(void)
{
	mutex_lock(&swap_slots_cache_mutex);
	swap_slot_cache_active = true;
	mutex_unlock(&swap_slots_cache_mutex);
}

/* Must not be called with cpu hot plug lock */
void disable_swap_slots_cache_lock(void)
{
	mutex_lock(&swap_slots_cache_enable_mutex);
	swap_slot_cache_enabled = false;
	if (swap_slot_cache_initialized) {
		/* serialize with cpu hotplug operations */
		get_online_cpus();
		__drain_swap_slots_cache(SLOTS_CACHE|SLOTS_CACHE_RET);
		put_online_cpus();
	}
}

static void __reenable_swap_slots_cache(void)
{
	swap_slot_cache_enabled = has_usable_swap();
}

void reenable_swap_slots_cache_unlock(void)
{
	__reenable_swap_slots_cache();
	mutex_unlock(&swap_slots_cache_enable_mutex);
}

static bool check_cache_active(void)
{
	long pages;

	if (!swap_slot_cache_enabled || !swap_slot_cache_initialized)
		return false;

	pages = get_nr_swap_pages();
	if (!swap_slot_cache_active) {
		if (pages > num_online_cpus() *
		    THRESHOLD_ACTIVATE_SWAP_SLOTS_CACHE)
			reactivate_swap_slots_cache();
		goto out;
	}

	/* if global pool of slot caches too low, deactivate cache */
	if (pages < num_online_cpus() * THRESHOLD_DEACTIVATE_SWAP_SLOTS_CACHE)
		deactivate_swap_slots_cache();
out:
	return swap_slot_cache_active;
}

static int alloc_swap_slot_cache(unsigned int cpu)
{
	struct swap_slots_cache *cache;
	swp_entry_t *slots, *slots_ret;

	/*
	 * Do allocation outside swap_slots_cache_mutex
	 * as kvzalloc could trigger reclaim and get_swap_page,
	 * which can lock swap_slots_cache_mutex.
	 */
	slots = kvcalloc(SWAP_SLOTS_CACHE_SIZE, sizeof(swp_entry_t),
			 GFP_KERNEL);
	if (!slots)
		return -ENOMEM;

	slots_ret = kvcalloc(SWAP_SLOTS_CACHE_SIZE, sizeof(swp_entry_t),
			     GFP_KERNEL);
	if (!slots_ret) {
		kvfree(slots);
		return -ENOMEM;
	}

	mutex_lock(&swap_slots_cache_mutex);
	cache = &per_cpu(swp_slots, cpu);
	if (cache->slots || cache->slots_ret)
		/* cache already allocated */
		goto out;
	if (!cache->lock_initialized) {
		mutex_init(&cache->alloc_lock);
		spin_lock_init(&cache->free_lock);
		cache->lock_initialized = true;
	}
	cache->nr = 0;
	cache->cur = 0;
	cache->n_ret = 0;
	/*
	 * We initialized alloc_lock and free_lock earlier.  We use
	 * !cache->slots or !cache->slots_ret to know if it is safe to acquire
	 * the corresponding lock and use the cache.  Memory barrier below
	 * ensures the assumption.
	 */
	mb();
	cache->slots = slots;
	slots = NULL;
	cache->slots_ret = slots_ret;
	slots_ret = NULL;
out:
	mutex_unlock(&swap_slots_cache_mutex);
	if (slots)
		kvfree(slots);
	if (slots_ret)
		kvfree(slots_ret);
	return 0;
}

static void drain_slots_cache_cpu(unsigned int cpu, unsigned int type,
				  bool free_slots)
{
	struct swap_slots_cache *cache;
	swp_entry_t *slots = NULL;

	cache = &per_cpu(swp_slots, cpu);
	if ((type & SLOTS_CACHE) && cache->slots) {
		mutex_lock(&cache->alloc_lock);
		swapcache_free_entries(cache->slots + cache->cur, cache->nr);
		cache->cur = 0;
		cache->nr = 0;
		if (free_slots && cache->slots) {
			kvfree(cache->slots);
			cache->slots = NULL;
		}
		mutex_unlock(&cache->alloc_lock);
	}
	if ((type & SLOTS_CACHE_RET) && cache->slots_ret) {
		spin_lock_irq(&cache->free_lock);
		swapcache_free_entries(cache->slots_ret, cache->n_ret);
		cache->n_ret = 0;
		if (free_slots && cache->slots_ret) {
			slots = cache->slots_ret;
			cache->slots_ret = NULL;
		}
		spin_unlock_irq(&cache->free_lock);
		if (slots)
			kvfree(slots);
	}
}

static void __drain_swap_slots_cache(unsigned int type)
{
	unsigned int cpu;

	/*
	 * This function is called during
	 *	1) swapoff, when we have to make sure no
	 *	   left over slots are in cache when we remove
	 *	   a swap device;
	 *      2) disabling of swap slot cache, when we run low
	 *	   on swap slots when allocating memory and need
	 *	   to return swap slots to global pool.
	 *
	 * We cannot acquire cpu hot plug lock here as
	 * this function can be invoked in the cpu
	 * hot plug path:
	 * cpu_up -> lock cpu_hotplug -> cpu hotplug state callback
	 *   -> memory allocation -> direct reclaim -> get_swap_page
	 *   -> drain_swap_slots_cache
	 *
	 * Hence the loop over current online cpu below could miss cpu that
	 * is being brought online but not yet marked as online.
	 * That is okay as we do not schedule and run anything on a
	 * cpu before it has been marked online. Hence, we will not
	 * fill any swap slots in slots cache of such cpu.
	 * There are no slots on such cpu that need to be drained.
	 */
	for_each_online_cpu(cpu)
		drain_slots_cache_cpu(cpu, type, false);
}

static int free_slot_cache(unsigned int cpu)
{
	mutex_lock(&swap_slots_cache_mutex);
	drain_slots_cache_cpu(cpu, SLOTS_CACHE | SLOTS_CACHE_RET, true);
	mutex_unlock(&swap_slots_cache_mutex);
	return 0;
}

int enable_swap_slots_cache(void)
{
	int ret = 0;

	mutex_lock(&swap_slots_cache_enable_mutex);
	if (swap_slot_cache_initialized) {
		__reenable_swap_slots_cache();
		goto out_unlock;
	}

	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "swap_slots_cache",
				alloc_swap_slot_cache, free_slot_cache);
	if (WARN_ONCE(ret < 0, "Cache allocation failed (%s), operating "
			       "without swap slots cache.\n", __func__))
		goto out_unlock;

	swap_slot_cache_initialized = true;
	__reenable_swap_slots_cache();
out_unlock:
	mutex_unlock(&swap_slots_cache_enable_mutex);
	return 0;
}

/* called with swap slot cache's alloc lock held */
static int refill_swap_slots_cache(struct swap_slots_cache *cache)
{
	if (!use_swap_slot_cache || cache->nr)
		return 0;

	cache->cur = 0;
	if (swap_slot_cache_active)
		cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
					   cache->slots, 1);

	return cache->nr;
}

int free_swap_slot(swp_entry_t entry)
{
	struct swap_slots_cache *cache;

	cache = raw_cpu_ptr(&swp_slots);
	if (likely(use_swap_slot_cache && cache->slots_ret)) {
		spin_lock_irq(&cache->free_lock);
		/* Swap slots cache may be deactivated before acquiring lock */
		if (!use_swap_slot_cache || !cache->slots_ret) {
			spin_unlock_irq(&cache->free_lock);
			goto direct_free;
		}
		if (cache->n_ret >= SWAP_SLOTS_CACHE_SIZE) {
			/*
			 * Return slots to global pool.
			 * The current swap_map value is SWAP_HAS_CACHE.
			 * Set it to 0 to indicate it is available for
			 * allocation in global pool
			 */
			swapcache_free_entries(cache->slots_ret, cache->n_ret);
			cache->n_ret = 0;
		}
		cache->slots_ret[cache->n_ret++] = entry;
		spin_unlock_irq(&cache->free_lock);
	} else {
direct_free:
		swapcache_free_entries(&entry, 1);
	}

	return 0;
}

swp_entry_t get_swap_page(struct page *page)
{
	swp_entry_t entry, *pentry;
	struct swap_slots_cache *cache;

	entry.val = 0;

	if (PageTransHuge(page)) {
		if (IS_ENABLED(CONFIG_THP_SWAP))
			get_swap_pages(1, &entry, HPAGE_PMD_NR);
		goto out;
	}

	/*
	 * Preemption is allowed here, because we may sleep
	 * in refill_swap_slots_cache().  But it is safe, because
	 * accesses to the per-CPU data structure are protected by the
	 * mutex cache->alloc_lock.
	 *
	 * The alloc path here does not touch cache->slots_ret
	 * so cache->free_lock is not taken.
	 */
	cache = raw_cpu_ptr(&swp_slots);

	if (likely(check_cache_active() && cache->slots)) {
		mutex_lock(&cache->alloc_lock);
		if (cache->slots) {
repeat:
			if (cache->nr)