Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 559 insertions, 0 deletions

diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c
new file mode 100644
index 0000000000..7fabc883e3
--- /dev/null
+++ b/block/blk-crypto-profile.c
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+/**
+ * DOC: blk-crypto profiles
+ *
+ * 'struct blk_crypto_profile' contains all generic inline encryption-related
+ * state for a particular inline encryption device.  blk_crypto_profile serves
+ * as the way that drivers for inline encryption hardware expose their crypto
+ * capabilities and certain functions (e.g., functions to program and evict
+ * keys) to upper layers.  Device drivers that want to support inline encryption
+ * construct a crypto profile, then associate it with the disk's request_queue.
+ *
+ * If the device has keyslots, then its blk_crypto_profile also handles managing
+ * these keyslots in a device-independent way, using the driver-provided
+ * functions to program and evict keys as needed.  This includes keeping track
+ * of which key and how many I/O requests are using each keyslot, getting
+ * keyslots for I/O requests, and handling key eviction requests.
+ *
+ * For more information, see Documentation/block/inline-encryption.rst.
+ */
+
+#define pr_fmt(fmt) "blk-crypto: " fmt
+
+#include <linux/blk-crypto-profile.h>
+#include <linux/device.h>
+#include <linux/atomic.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/wait.h>
+#include <linux/blkdev.h>
+#include <linux/blk-integrity.h>
+#include "blk-crypto-internal.h"
+
+struct blk_crypto_keyslot {
+	atomic_t slot_refs;
+	struct list_head idle_slot_node;
+	struct hlist_node hash_node;
+	const struct blk_crypto_key *key;
+	struct blk_crypto_profile *profile;
+};
+
+static inline void blk_crypto_hw_enter(struct blk_crypto_profile *profile)
+{
+	/*
+	 * Calling into the driver requires profile->lock held and the device
+	 * resumed.  But we must resume the device first, since that can acquire
+	 * and release profile->lock via blk_crypto_reprogram_all_keys().
+	 */
+	if (profile->dev)
+		pm_runtime_get_sync(profile->dev);
+	down_write(&profile->lock);
+}
+
+static inline void blk_crypto_hw_exit(struct blk_crypto_profile *profile)
+{
+	up_write(&profile->lock);
+	if (profile->dev)
+		pm_runtime_put_sync(profile->dev);
+}
+
+/**
+ * blk_crypto_profile_init() - Initialize a blk_crypto_profile
+ * @profile: the blk_crypto_profile to initialize
+ * @num_slots: the number of keyslots
+ *
+ * Storage drivers must call this when starting to set up a blk_crypto_profile,
+ * before filling in additional fields.
+ *
+ * Return: 0 on success, or else a negative error code.
+ */
+int blk_crypto_profile_init(struct blk_crypto_profile *profile,
+			    unsigned int num_slots)
+{
+	unsigned int slot;
+	unsigned int i;
+	unsigned int slot_hashtable_size;
+
+	memset(profile, 0, sizeof(*profile));
+
+	/*
+	 * profile->lock of an underlying device can nest inside profile->lock
+	 * of a device-mapper device, so use a dynamic lock class to avoid
+	 * false-positive lockdep reports.
+	 */
+	lockdep_register_key(&profile->lockdep_key);
+	__init_rwsem(&profile->lock, "&profile->lock", &profile->lockdep_key);
+
+	if (num_slots == 0)
+		return 0;
+
+	/* Initialize keyslot management data. */
+
+	profile->slots = kvcalloc(num_slots, sizeof(profile->slots[0]),
+				  GFP_KERNEL);
+	if (!profile->slots)
+		goto err_destroy;
+
+	profile->num_slots = num_slots;
+
+	init_waitqueue_head(&profile->idle_slots_wait_queue);
+	INIT_LIST_HEAD(&profile->idle_slots);
+
+	for (slot = 0; slot < num_slots; slot++) {
+		profile->slots[slot].profile = profile;
+		list_add_tail(&profile->slots[slot].idle_slot_node,
+			      &profile->idle_slots);
+	}
+
+	spin_lock_init(&profile->idle_slots_lock);
+
+	slot_hashtable_size = roundup_pow_of_two(num_slots);
+	/*
+	 * hash_ptr() assumes bits != 0, so ensure the hash table has at least 2
+	 * buckets.  This only makes a difference when there is only 1 keyslot.
+	 */
+	if (slot_hashtable_size < 2)
+		slot_hashtable_size = 2;
+
+	profile->log_slot_ht_size = ilog2(slot_hashtable_size);
+	profile->slot_hashtable =
+		kvmalloc_array(slot_hashtable_size,
+			       sizeof(profile->slot_hashtable[0]), GFP_KERNEL);
+	if (!profile->slot_hashtable)
+		goto err_destroy;
+	for (i = 0; i < slot_hashtable_size; i++)
+		INIT_HLIST_HEAD(&profile->slot_hashtable[i]);
+
+	return 0;
+
+err_destroy:
+	blk_crypto_profile_destroy(profile);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(blk_crypto_profile_init);
+
+static void blk_crypto_profile_destroy_callback(void *profile)
+{
+	blk_crypto_profile_destroy(profile);
+}
+
+/**
+ * devm_blk_crypto_profile_init() - Resource-managed blk_crypto_profile_init()
+ * @dev: the device which owns the blk_crypto_profile
+ * @profile: the blk_crypto_profile to initialize
+ * @num_slots: the number of keyslots
+ *
+ * Like blk_crypto_profile_init(), but causes blk_crypto_profile_destroy() to be
+ * called automatically on driver detach.
+ *
+ * Return: 0 on success, or else a negative error code.
+ */
+int devm_blk_crypto_profile_init(struct device *dev,
+				 struct blk_crypto_profile *profile,
+				 unsigned int num_slots)
+{
+	int err = blk_crypto_profile_init(profile, num_slots);
+
+	if (err)
+		return err;
+
+	return devm_add_action_or_reset(dev,
+					blk_crypto_profile_destroy_callback,
+					profile);
+}
+EXPORT_SYMBOL_GPL(devm_blk_crypto_profile_init);
+
+static inline struct hlist_head *
+blk_crypto_hash_bucket_for_key(struct blk_crypto_profile *profile,
+			       const struct blk_crypto_key *key)
+{
+	return &profile->slot_hashtable[
+			hash_ptr(key, profile->log_slot_ht_size)];
+}
+
+static void
+blk_crypto_remove_slot_from_lru_list(struct blk_crypto_keyslot *slot)
+{
+	struct blk_crypto_profile *profile = slot->profile;
+	unsigned long flags;
+
+	spin_lock_irqsave(&profile->idle_slots_lock, flags);
+	list_del(&slot->idle_slot_node);
+	spin_unlock_irqrestore(&profile->idle_slots_lock, flags);
+}
+
+static struct blk_crypto_keyslot *
+blk_crypto_find_keyslot(struct blk_crypto_profile *profile,
+			const struct blk_crypto_key *key)
+{
+	const struct hlist_head *head =
+		blk_crypto_hash_bucket_for_key(profile, key);
+	struct blk_crypto_keyslot *slotp;
+
+	hlist_for_each_entry(slotp, head, hash_node) {
+		if (slotp->key == key)
+			return slotp;
+	}
+	return NULL;
+}
+
+static struct blk_crypto_keyslot *
+blk_crypto_find_and_grab_keyslot(struct blk_crypto_profile *profile,
+				 const struct blk_crypto_key *key)
+{
+	struct blk_crypto_keyslot *slot;
+
+	slot = blk_crypto_find_keyslot(profile, key);
+	if (!slot)
+		return NULL;
+	if (atomic_inc_return(&slot->slot_refs) == 1) {
+		/* Took first reference to this slot; remove it from LRU list */
+		blk_crypto_remove_slot_from_lru_list(slot);
+	}
+	return slot;
+}
+
+/**
+ * blk_crypto_keyslot_index() - Get the index of a keyslot
+ * @slot: a keyslot that blk_crypto_get_keyslot() returned
+ *
+ * Return: the 0-based index of the keyslot within the device's keyslots.
+ */
+unsigned int blk_crypto_keyslot_index(struct blk_crypto_keyslot *slot)
+{
+	return slot - slot->profile->slots;
+}
+EXPORT_SYMBOL_GPL(blk_crypto_keyslot_index);
+
+/**
+ * blk_crypto_get_keyslot() - Get a keyslot for a key, if needed.
+ * @profile: the crypto profile of the device the key will be used on
+ * @key: the key that will be used
+ * @slot_ptr: If a keyslot is allocated, an opaque pointer to the keyslot struct
+ *	      will be stored here.  blk_crypto_put_keyslot() must be called
+ *	      later to release it.  Otherwise, NULL will be stored here.
+ *
+ * If the device has keyslots, this gets a keyslot that's been programmed with
+ * the specified key.  If the key is already in a slot, this reuses it;
+ * otherwise this waits for a slot to become idle and programs the key into it.
+ *
+ * Context: Process context. Takes and releases profile->lock.
+ * Return: BLK_STS_OK on success, meaning that either a keyslot was allocated or
+ *	   one wasn't needed; or a blk_status_t error on failure.
+ */
+blk_status_t blk_crypto_get_keyslot(struct blk_crypto_profile *profile,
+				    const struct blk_crypto_key *key,
+				    struct blk_crypto_keyslot **slot_ptr)
+{
+	struct blk_crypto_keyslot *slot;
+	int slot_idx;
+	int err;
+
+	*slot_ptr = NULL;
+
+	/*
+	 * If the device has no concept of "keyslots", then there is no need to
+	 * get one.
+	 */
+	if (profile->num_slots == 0)
+		return BLK_STS_OK;
+
+	down_read(&profile->lock);
+	slot = blk_crypto_find_and_grab_keyslot(profile, key);
+	up_read(&profile->lock);
+	if (slot)
+		goto success;
+
+	for (;;) {
+		blk_crypto_hw_enter(profile);
+		slot = blk_crypto_find_and_grab_keyslot(profile, key);
+		if (slot) {
+			blk_crypto_hw_exit(profile);
+			goto success;
+		}
+
+		/*
+		 * If we're here, that means there wasn't a slot that was
+		 * already programmed with the key. So try to program it.
+		 */
+		if (!list_empty(&profile->idle_slots))
+			break;
+
+		blk_crypto_hw_exit(profile);
+		wait_event(profile->idle_slots_wait_queue,
+			   !list_empty(&profile->idle_slots));
+	}
+
+	slot = list_first_entry(&profile->idle_slots, struct blk_crypto_keyslot,
+				idle_slot_node);
+	slot_idx = blk_crypto_keyslot_index(slot);
+
+	err = profile->ll_ops.keyslot_program(profile, key, slot_idx);
+	if (err) {
+		wake_up(&profile->idle_slots_wait_queue);
+		blk_crypto_hw_exit(profile);
+		return errno_to_blk_status(err);
+	}
+
+	/* Move this slot to the hash list for the new key. */
+	if (slot->key)
+		hlist_del(&slot->hash_node);
+	slot->key = key;
+	hlist_add_head(&slot->hash_node,
+		       blk_crypto_hash_bucket_for_key(profile, key));
+
+	atomic_set(&slot->slot_refs, 1);
+
+	blk_crypto_remove_slot_from_lru_list(slot);
+
+	blk_crypto_hw_exit(profile);
+success:
+	*slot_ptr = slot;
+	return BLK_STS_OK;
+}
+
+/**
+ * blk_crypto_put_keyslot() - Release a reference to a keyslot
+ * @slot: The keyslot to release the reference of
+ *
+ * Context: Any context.
+ */
+void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot)
+{
+	struct blk_crypto_profile *profile = slot->profile;
+	unsigned long flags;
+
+	if (atomic_dec_and_lock_irqsave(&slot->slot_refs,
+					&profile->idle_slots_lock, flags)) {
+		list_add_tail(&slot->idle_slot_node, &profile->idle_slots);
+		spin_unlock_irqrestore(&profile->idle_slots_lock, flags);
+		wake_up(&profile->idle_slots_wait_queue);
+	}
+}
+
+/**
+ * __blk_crypto_cfg_supported() - Check whether the given crypto profile
+ *				  supports the given crypto configuration.
+ * @profile: the crypto profile to check
+ * @cfg: the crypto configuration to check for
+ *
+ * Return: %true if @profile supports the given @cfg.
+ */
+bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile,
+				const struct blk_crypto_config *cfg)
+{
+	if (!profile)
+		return false;
+	if (!(profile->modes_supported[cfg->crypto_mode] & cfg->data_unit_size))
+		return false;
+	if (profile->max_dun_bytes_supported < cfg->dun_bytes)
+		return false;
+	return true;
+}
+
+/*
+ * This is an internal function that evicts a key from an inline encryption
+ * device that can be either a real device or the blk-crypto-fallback "device".
+ * It is used only by blk_crypto_evict_key(); see that function for details.
+ */
+int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
+			   const struct blk_crypto_key *key)
+{
+	struct blk_crypto_keyslot *slot;
+	int err;
+
+	if (profile->num_slots == 0) {
+		if (profile->ll_ops.keyslot_evict) {
+			blk_crypto_hw_enter(profile);
+			err = profile->ll_ops.keyslot_evict(profile, key, -1);
+			blk_crypto_hw_exit(profile);
+			return err;
+		}
+		return 0;
+	}
+
+	blk_crypto_hw_enter(profile);
+	slot = blk_crypto_find_keyslot(profile, key);
+	if (!slot) {
+		/*
+		 * Not an error, since a key not in use by I/O is not guaranteed
+		 * to be in a keyslot.  There can be more keys than keyslots.
+		 */
+		err = 0;
+		goto out;
+	}
+
+	if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {
+		/* BUG: key is still in use by I/O */
+		err = -EBUSY;
+		goto out_remove;
+	}
+	err = profile->ll_ops.keyslot_evict(profile, key,
+					    blk_crypto_keyslot_index(slot));
+out_remove:
+	/*
+	 * Callers free the key even on error, so unlink the key from the hash
+	 * table and clear slot->key even on error.
+	 */
+	hlist_del(&slot->hash_node);
+	slot->key = NULL;
+out:
+	blk_crypto_hw_exit(profile);
+	return err;
+}
+
+/**
+ * blk_crypto_reprogram_all_keys() - Re-program all keyslots.
+ * @profile: The crypto profile
+ *
+ * Re-program all keyslots that are supposed to have a key programmed.  This is
+ * intended only for use by drivers for hardware that loses its keys on reset.
+ *
+ * Context: Process context. Takes and releases profile->lock.
+ */
+void blk_crypto_reprogram_all_keys(struct blk_crypto_profile *profile)
+{
+	unsigned int slot;
+
+	if (profile->num_slots == 0)
+		return;
+
+	/* This is for device initialization, so don't resume the device */
+	down_write(&profile->lock);
+	for (slot = 0; slot < profile->num_slots; slot++) {
+		const struct blk_crypto_key *key = profile->slots[slot].key;
+		int err;
+
+		if (!key)
+			continue;
+
+		err = profile->ll_ops.keyslot_program(profile, key, slot);
+		WARN_ON(err);
+	}
+	up_write(&profile->lock);
+}
+EXPORT_SYMBOL_GPL(blk_crypto_reprogram_all_keys);
+
+void blk_crypto_profile_destroy(struct blk_crypto_profile *profile)
+{
+	if (!profile)
+		return;
+	lockdep_unregister_key(&profile->lockdep_key);
+	kvfree(profile->slot_hashtable);
+	kvfree_sensitive(profile->slots,
+			 sizeof(profile->slots[0]) * profile->num_slots);
+	memzero_explicit(profile, sizeof(*profile));
+}
+EXPORT_SYMBOL_GPL(blk_crypto_profile_destroy);
+
+bool blk_crypto_register(struct blk_crypto_profile *profile,
+			 struct request_queue *q)
+{
+	if (blk_integrity_queue_supports_integrity(q)) {
+		pr_warn("Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n");
+		return false;
+	}
+	q->crypto_profile = profile;
+	return true;
+}
+EXPORT_SYMBOL_GPL(blk_crypto_register);
+
+/**
+ * blk_crypto_intersect_capabilities() - restrict supported crypto capabilities
+ *					 by child device
+ * @parent: the crypto profile for the parent device
+ * @child: the crypto profile for the child device, or NULL
+ *
+ * This clears all crypto capabilities in @parent that aren't set in @child.  If
+ * @child is NULL, then this clears all parent capabilities.
+ *
+ * Only use this when setting up the crypto profile for a layered device, before
+ * it's been exposed yet.
+ */
+void blk_crypto_intersect_capabilities(struct blk_crypto_profile *parent,
+				       const struct blk_crypto_profile *child)
+{
+	if (child) {
+		unsigned int i;
+
+		parent->max_dun_bytes_supported =
+			min(parent->max_dun_bytes_supported,
+			    child->max_dun_bytes_supported);
+		for (i = 0; i < ARRAY_SIZE(child->modes_supported); i++)
+			parent->modes_supported[i] &= child->modes_supported[i];
+	} else {
+		parent->max_dun_bytes_supported = 0;
+		memset(parent->modes_supported, 0,
+		       sizeof(parent->modes_supported));
+	}
+}
+EXPORT_SYMBOL_GPL(blk_crypto_intersect_capabilities);
+
+/**
+ * blk_crypto_has_capabilities() - Check whether @target supports at least all
+ *				   the crypto capabilities that @reference does.
+ * @target: the target profile
+ * @reference: the reference profile
+ *
+ * Return: %true if @target supports all the crypto capabilities of @reference.
+ */
+bool blk_crypto_has_capabilities(const struct blk_crypto_profile *target,
+				 const struct blk_crypto_profile *reference)
+{
+	int i;
+
+	if (!reference)
+		return true;
+
+	if (!target)
+		return false;
+
+	for (i = 0; i < ARRAY_SIZE(target->modes_supported); i++) {
+		if (reference->modes_supported[i] & ~target->modes_supported[i])
+			return false;
+	}
+
+	if (reference->max_dun_bytes_supported >
+	    target->max_dun_bytes_supported)
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(blk_crypto_has_capabilities);
+
+/**
+ * blk_crypto_update_capabilities() - Update the capabilities of a crypto
+ *				      profile to match those of another crypto
+ *				      profile.
+ * @dst: The crypto profile whose capabilities to update.
+ * @src: The crypto profile whose capabilities this function will update @dst's
+ *	 capabilities to.
+ *
+ * Blk-crypto requires that crypto capabilities that were
+ * advertised when a bio was created continue to be supported by the
+ * device until that bio is ended. This is turn means that a device cannot
+ * shrink its advertised crypto capabilities without any explicit
+ * synchronization with upper layers. So if there's no such explicit
+ * synchronization, @src must support all the crypto capabilities that
+ * @dst does (i.e. we need blk_crypto_has_capabilities(@src, @dst)).
+ *
+ * Note also that as long as the crypto capabilities are being expanded, the
+ * order of updates becoming visible is not important because it's alright
+ * for blk-crypto to see stale values - they only cause blk-crypto to
+ * believe that a crypto capability isn't supported when it actually is (which
+ * might result in blk-crypto-fallback being used if available, or the bio being
+ * failed).
+ */
+void blk_crypto_update_capabilities(struct blk_crypto_profile *dst,
+				    const struct blk_crypto_profile *src)
+{
+	memcpy(dst->modes_supported, src->modes_supported,
+	       sizeof(dst->modes_supported));
+
+	dst->max_dun_bytes_supported = src->max_dun_bytes_supported;
+}
+EXPORT_SYMBOL_GPL(blk_crypto_update_capabilities);