1 // SPDX-License-Identifier: GPL-2.0
65 /* Must not be called with cpu hot plug lock */
124 		return -ENOMEM;  in alloc_swap_slot_cache()
128 	if (cache->slots) {  in alloc_swap_slot_cache()
137 	if (!cache->lock_initialized) {  in alloc_swap_slot_cache()
138 		mutex_init(&cache->alloc_lock);  in alloc_swap_slot_cache()
139 		cache->lock_initialized = true;  in alloc_swap_slot_cache()
141 	cache->nr = 0;  in alloc_swap_slot_cache()
142 	cache->cur = 0;  in alloc_swap_slot_cache()
143 	cache->n_ret = 0;  in alloc_swap_slot_cache()
146 	 * !cache->slots or !cache->slots_ret to know if it is safe to acquire  in alloc_swap_slot_cache()
151 	cache->slots = slots;  in alloc_swap_slot_cache()
161 	if (cache->slots) {  in drain_slots_cache_cpu()
162 		mutex_lock(&cache->alloc_lock);  in drain_slots_cache_cpu()
163 		swapcache_free_entries(cache->slots + cache->cur, cache->nr);  in drain_slots_cache_cpu()
164 		cache->cur = 0;  in drain_slots_cache_cpu()
165 		cache->nr = 0;  in drain_slots_cache_cpu()
166 		if (free_slots && cache->slots) {  in drain_slots_cache_cpu()
167 			kvfree(cache->slots);  in drain_slots_cache_cpu()
168 			cache->slots = NULL;  in drain_slots_cache_cpu()
170 		mutex_unlock(&cache->alloc_lock);  in drain_slots_cache_cpu()
187 	 * We cannot acquire cpu hot plug lock here as  in __drain_swap_slots_cache()
189 	 * hot plug path:  in __drain_swap_slots_cache()
190 	 * cpu_up -> lock cpu_hotplug -> cpu hotplug state callback  in __drain_swap_slots_cache()
191 	 *   -> memory allocation -> direct reclaim -> folio_alloc_swap  in __drain_swap_slots_cache()
192 	 *   -> drain_swap_slots_cache  in __drain_swap_slots_cache()
239 	cache->cur = 0;  in refill_swap_slots_cache()
241 		cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,  in refill_swap_slots_cache()
242 					   cache->slots, 0);  in refill_swap_slots_cache()
244 	return cache->nr;  in refill_swap_slots_cache()
263 	 * accesses to the per-CPU data structure are protected by the  in folio_alloc_swap()
264 	 * mutex cache->alloc_lock.  in folio_alloc_swap()
266 	 * The alloc path here does not touch cache->slots_ret  in folio_alloc_swap()
267 	 * so cache->free_lock is not taken.  in folio_alloc_swap()
271 	if (likely(check_cache_active() && cache->slots)) {  in folio_alloc_swap()
272 		mutex_lock(&cache->alloc_lock);  in folio_alloc_swap()
273 		if (cache->slots) {  in folio_alloc_swap()
275 			if (cache->nr) {  in folio_alloc_swap()
276 				entry = cache->slots[cache->cur];  in folio_alloc_swap()
277 				cache->slots[cache->cur++].val = 0;  in folio_alloc_swap()
278 				cache->nr--;  in folio_alloc_swap()
283 		mutex_unlock(&cache->alloc_lock);  in folio_alloc_swap()