1 // SPDX-License-Identifier: GPL-2.0
7  * DOC: blk-crypto profiles
9  * 'struct blk_crypto_profile' contains all generic inline encryption-related
17  * these keyslots in a device-independent way, using the driver-provided
19  * of which key and how many I/O requests are using each keyslot, getting
20  * keyslots for I/O requests, and handling key eviction requests.
22  * For more information, see Documentation/block/inline-encryption.rst.
25 #define pr_fmt(fmt) "blk-crypto: " fmt
27 #include <linux/blk-crypto-profile.h>
34 #include <linux/blk-integrity.h>
35 #include "blk-crypto-internal.h"
41 	const struct blk_crypto_key *key;  member
48 	 * Calling into the driver requires profile->lock held and the device  in blk_crypto_hw_enter()
50 	 * and release profile->lock via blk_crypto_reprogram_all_keys().  in blk_crypto_hw_enter()
52 	if (profile->dev)  in blk_crypto_hw_enter()
53 		pm_runtime_get_sync(profile->dev);  in blk_crypto_hw_enter()
54 	down_write(&profile->lock);  in blk_crypto_hw_enter()
59 	up_write(&profile->lock);  in blk_crypto_hw_exit()
60 	if (profile->dev)  in blk_crypto_hw_exit()
61 		pm_runtime_put_sync(profile->dev);  in blk_crypto_hw_exit()
65  * blk_crypto_profile_init() - Initialize a blk_crypto_profile
84 	 * profile->lock of an underlying device can nest inside profile->lock  in blk_crypto_profile_init()
85 	 * of a device-mapper device, so use a dynamic lock class to avoid  in blk_crypto_profile_init()
86 	 * false-positive lockdep reports.  in blk_crypto_profile_init()
88 	lockdep_register_key(&profile->lockdep_key);  in blk_crypto_profile_init()
89 	__init_rwsem(&profile->lock, "&profile->lock", &profile->lockdep_key);  in blk_crypto_profile_init()
96 	profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),  in blk_crypto_profile_init()
98 	if (!profile->slots)  in blk_crypto_profile_init()
101 	profile->num_slots = num_slots;  in blk_crypto_profile_init()
103 	init_waitqueue_head(&profile->idle_slots_wait_queue);  in blk_crypto_profile_init()
104 	INIT_LIST_HEAD(&profile->idle_slots);  in blk_crypto_profile_init()
107 		profile->slots[slot].profile = profile;  in blk_crypto_profile_init()
108 		list_add_tail(&profile->slots[slot].idle_slot_node,  in blk_crypto_profile_init()
109 			      &profile->idle_slots);  in blk_crypto_profile_init()
112 	spin_lock_init(&profile->idle_slots_lock);  in blk_crypto_profile_init()
122 	profile->log_slot_ht_size = ilog2(slot_hashtable_size);  in blk_crypto_profile_init()
123 	profile->slot_hashtable =  in blk_crypto_profile_init()
125 			       sizeof(profile->slot_hashtable[0]), GFP_KERNEL);  in blk_crypto_profile_init()
126 	if (!profile->slot_hashtable)  in blk_crypto_profile_init()
129 		INIT_HLIST_HEAD(&profile->slot_hashtable[i]);  in blk_crypto_profile_init()
135 	return -ENOMEM;  in blk_crypto_profile_init()
145  * devm_blk_crypto_profile_init() - Resource-managed blk_crypto_profile_init()
172 			       const struct blk_crypto_key *key)  in blk_crypto_hash_bucket_for_key()  argument
174 	return &profile->slot_hashtable[  in blk_crypto_hash_bucket_for_key()
175 			hash_ptr(key, profile->log_slot_ht_size)];  in blk_crypto_hash_bucket_for_key()
181 	struct blk_crypto_profile *profile = slot->profile;  in blk_crypto_remove_slot_from_lru_list()
184 	spin_lock_irqsave(&profile->idle_slots_lock, flags);  in blk_crypto_remove_slot_from_lru_list()
185 	list_del(&slot->idle_slot_node);  in blk_crypto_remove_slot_from_lru_list()
186 	spin_unlock_irqrestore(&profile->idle_slots_lock, flags);  in blk_crypto_remove_slot_from_lru_list()
191 			const struct blk_crypto_key *key)  in blk_crypto_find_keyslot()  argument
194 		blk_crypto_hash_bucket_for_key(profile, key);  in blk_crypto_find_keyslot()
198 		if (slotp->key == key)  in blk_crypto_find_keyslot()
206 				 const struct blk_crypto_key *key)  in blk_crypto_find_and_grab_keyslot()  argument
210 	slot = blk_crypto_find_keyslot(profile, key);  in blk_crypto_find_and_grab_keyslot()
213 	if (atomic_inc_return(&slot->slot_refs) == 1) {  in blk_crypto_find_and_grab_keyslot()
221  * blk_crypto_keyslot_index() - Get the index of a keyslot
224  * Return: the 0-based index of the keyslot within the device's keyslots.
228 	return slot - slot->profile->slots;  in blk_crypto_keyslot_index()
233  * blk_crypto_get_keyslot() - Get a keyslot for a key, if needed.
234  * @profile: the crypto profile of the device the key will be used on
235  * @key: the key that will be used
238  *	      later to release it.  Otherwise, NULL will be stored here.
241  * the specified key.  If the key is already in a slot, this reuses it;
242  * otherwise this waits for a slot to become idle and programs the key into it.
244  * Context: Process context. Takes and releases profile->lock.
249 				    const struct blk_crypto_key *key,  in blk_crypto_get_keyslot()  argument
262 	if (profile->num_slots == 0)  in blk_crypto_get_keyslot()
265 	down_read(&profile->lock);  in blk_crypto_get_keyslot()
266 	slot = blk_crypto_find_and_grab_keyslot(profile, key);  in blk_crypto_get_keyslot()
267 	up_read(&profile->lock);  in blk_crypto_get_keyslot()
273 		slot = blk_crypto_find_and_grab_keyslot(profile, key);  in blk_crypto_get_keyslot()
281 		 * already programmed with the key. So try to program it.  in blk_crypto_get_keyslot()
283 		if (!list_empty(&profile->idle_slots))  in blk_crypto_get_keyslot()
287 		wait_event(profile->idle_slots_wait_queue,  in blk_crypto_get_keyslot()
288 			   !list_empty(&profile->idle_slots));  in blk_crypto_get_keyslot()
291 	slot = list_first_entry(&profile->idle_slots, struct blk_crypto_keyslot,  in blk_crypto_get_keyslot()
295 	err = profile->ll_ops.keyslot_program(profile, key, slot_idx);  in blk_crypto_get_keyslot()
297 		wake_up(&profile->idle_slots_wait_queue);  in blk_crypto_get_keyslot()
302 	/* Move this slot to the hash list for the new key. */  in blk_crypto_get_keyslot()
303 	if (slot->key)  in blk_crypto_get_keyslot()
304 		hlist_del(&slot->hash_node);  in blk_crypto_get_keyslot()
305 	slot->key = key;  in blk_crypto_get_keyslot()
306 	hlist_add_head(&slot->hash_node,  in blk_crypto_get_keyslot()
307 		       blk_crypto_hash_bucket_for_key(profile, key));  in blk_crypto_get_keyslot()
309 	atomic_set(&slot->slot_refs, 1);  in blk_crypto_get_keyslot()
320  * blk_crypto_put_keyslot() - Release a reference to a keyslot
321  * @slot: The keyslot to release the reference of
327 	struct blk_crypto_profile *profile = slot->profile;  in blk_crypto_put_keyslot()
330 	if (atomic_dec_and_lock_irqsave(&slot->slot_refs,  in blk_crypto_put_keyslot()
331 					&profile->idle_slots_lock, flags)) {  in blk_crypto_put_keyslot()
332 		list_add_tail(&slot->idle_slot_node, &profile->idle_slots);  in blk_crypto_put_keyslot()
333 		spin_unlock_irqrestore(&profile->idle_slots_lock, flags);  in blk_crypto_put_keyslot()
334 		wake_up(&profile->idle_slots_wait_queue);  in blk_crypto_put_keyslot()
339  * __blk_crypto_cfg_supported() - Check whether the given crypto profile
351 	if (!(profile->modes_supported[cfg->crypto_mode] & cfg->data_unit_size))  in __blk_crypto_cfg_supported()
353 	if (profile->max_dun_bytes_supported < cfg->dun_bytes)  in __blk_crypto_cfg_supported()
359  * This is an internal function that evicts a key from an inline encryption
360  * device that can be either a real device or the blk-crypto-fallback "device".
364 			   const struct blk_crypto_key *key)  in __blk_crypto_evict_key()  argument
369 	if (profile->num_slots == 0) {  in __blk_crypto_evict_key()
370 		if (profile->ll_ops.keyslot_evict) {  in __blk_crypto_evict_key()
372 			err = profile->ll_ops.keyslot_evict(profile, key, -1);  in __blk_crypto_evict_key()
380 	slot = blk_crypto_find_keyslot(profile, key);  in __blk_crypto_evict_key()
383 		 * Not an error, since a key not in use by I/O is not guaranteed  in __blk_crypto_evict_key()
390 	if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {  in __blk_crypto_evict_key()
391 		/* BUG: key is still in use by I/O */  in __blk_crypto_evict_key()
392 		err = -EBUSY;  in __blk_crypto_evict_key()
395 	err = profile->ll_ops.keyslot_evict(profile, key,  in __blk_crypto_evict_key()
399 	 * Callers free the key even on error, so unlink the key from the hash  in __blk_crypto_evict_key()
400 	 * table and clear slot->key even on error.  in __blk_crypto_evict_key()
402 	hlist_del(&slot->hash_node);  in __blk_crypto_evict_key()
403 	slot->key = NULL;  in __blk_crypto_evict_key()
410  * blk_crypto_reprogram_all_keys() - Re-program all keyslots.
413  * Re-program all keyslots that are supposed to have a key programmed.  This is
416  * Context: Process context. Takes and releases profile->lock.
422 	if (profile->num_slots == 0)  in blk_crypto_reprogram_all_keys()
426 	down_write(&profile->lock);  in blk_crypto_reprogram_all_keys()
427 	for (slot = 0; slot < profile->num_slots; slot++) {  in blk_crypto_reprogram_all_keys()
428 		const struct blk_crypto_key *key = profile->slots[slot].key;  in blk_crypto_reprogram_all_keys()  local
431 		if (!key)  in blk_crypto_reprogram_all_keys()
434 		err = profile->ll_ops.keyslot_program(profile, key, slot);  in blk_crypto_reprogram_all_keys()
437 	up_write(&profile->lock);  in blk_crypto_reprogram_all_keys()
445 	lockdep_unregister_key(&profile->lockdep_key);  in blk_crypto_profile_destroy()
446 	kvfree(profile->slot_hashtable);  in blk_crypto_profile_destroy()
447 	kvfree_sensitive(profile->slots,  in blk_crypto_profile_destroy()
448 			 sizeof(profile->slots[0]) * profile->num_slots);  in blk_crypto_profile_destroy()
460 	q->crypto_profile = profile;  in blk_crypto_register()
466  * blk_crypto_intersect_capabilities() - restrict supported crypto capabilities
483 		parent->max_dun_bytes_supported =  in blk_crypto_intersect_capabilities()
484 			min(parent->max_dun_bytes_supported,  in blk_crypto_intersect_capabilities()
485 			    child->max_dun_bytes_supported);  in blk_crypto_intersect_capabilities()
486 		for (i = 0; i < ARRAY_SIZE(child->modes_supported); i++)  in blk_crypto_intersect_capabilities()
487 			parent->modes_supported[i] &= child->modes_supported[i];  in blk_crypto_intersect_capabilities()
489 		parent->max_dun_bytes_supported = 0;  in blk_crypto_intersect_capabilities()
490 		memset(parent->modes_supported, 0,  in blk_crypto_intersect_capabilities()
491 		       sizeof(parent->modes_supported));  in blk_crypto_intersect_capabilities()
497  * blk_crypto_has_capabilities() - Check whether @target supports at least all
515 	for (i = 0; i < ARRAY_SIZE(target->modes_supported); i++) {  in blk_crypto_has_capabilities()
516 		if (reference->modes_supported[i] & ~target->modes_supported[i])  in blk_crypto_has_capabilities()
520 	if (reference->max_dun_bytes_supported >  in blk_crypto_has_capabilities()
521 	    target->max_dun_bytes_supported)  in blk_crypto_has_capabilities()
529  * blk_crypto_update_capabilities() - Update the capabilities of a crypto
536  * Blk-crypto requires that crypto capabilities that were
546  * for blk-crypto to see stale values - they only cause blk-crypto to
548  * might result in blk-crypto-fallback being used if available, or the bio being
554 	memcpy(dst->modes_supported, src->modes_supported,  in blk_crypto_update_capabilities()
555 	       sizeof(dst->modes_supported));  in blk_crypto_update_capabilities()
557 	dst->max_dun_bytes_supported = src->max_dun_bytes_supported;  in blk_crypto_update_capabilities()