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-rw-r--r--include/linux/keyslot-manager.h106
1 files changed, 106 insertions, 0 deletions
diff --git a/include/linux/keyslot-manager.h b/include/linux/keyslot-manager.h
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+++ b/include/linux/keyslot-manager.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#ifndef __LINUX_KEYSLOT_MANAGER_H
+#define __LINUX_KEYSLOT_MANAGER_H
+
+#include <linux/bio.h>
+#include <linux/blk-crypto.h>
+
+struct blk_keyslot_manager;
+
+/**
+ * struct blk_ksm_ll_ops - functions to manage keyslots in hardware
+ * @keyslot_program: Program the specified key into the specified slot in the
+ * inline encryption hardware.
+ * @keyslot_evict: Evict key from the specified keyslot in the hardware.
+ * The key is provided so that e.g. dm layers can evict
+ * keys from the devices that they map over.
+ * Returns 0 on success, -errno otherwise.
+ *
+ * This structure should be provided by storage device drivers when they set up
+ * a keyslot manager - this structure holds the function ptrs that the keyslot
+ * manager will use to manipulate keyslots in the hardware.
+ */
+struct blk_ksm_ll_ops {
+ int (*keyslot_program)(struct blk_keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ unsigned int slot);
+ int (*keyslot_evict)(struct blk_keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ unsigned int slot);
+};
+
+struct blk_keyslot_manager {
+ /*
+ * The struct blk_ksm_ll_ops that this keyslot manager will use
+ * to perform operations like programming and evicting keys on the
+ * device
+ */
+ struct blk_ksm_ll_ops ksm_ll_ops;
+
+ /*
+ * The maximum number of bytes supported for specifying the data unit
+ * number.
+ */
+ unsigned int max_dun_bytes_supported;
+
+ /*
+ * Array of size BLK_ENCRYPTION_MODE_MAX of bitmasks that represents
+ * whether a crypto mode and data unit size are supported. The i'th
+ * bit of crypto_mode_supported[crypto_mode] is set iff a data unit
+ * size of (1 << i) is supported. We only support data unit sizes
+ * that are powers of 2.
+ */
+ unsigned int crypto_modes_supported[BLK_ENCRYPTION_MODE_MAX];
+
+ /* Device for runtime power management (NULL if none) */
+ struct device *dev;
+
+ /* Here onwards are *private* fields for internal keyslot manager use */
+
+ unsigned int num_slots;
+
+ /* Protects programming and evicting keys from the device */
+ struct rw_semaphore lock;
+
+ /* List of idle slots, with least recently used slot at front */
+ wait_queue_head_t idle_slots_wait_queue;
+ struct list_head idle_slots;
+ spinlock_t idle_slots_lock;
+
+ /*
+ * Hash table which maps struct *blk_crypto_key to keyslots, so that we
+ * can find a key's keyslot in O(1) time rather than O(num_slots).
+ * Protected by 'lock'.
+ */
+ struct hlist_head *slot_hashtable;
+ unsigned int log_slot_ht_size;
+
+ /* Per-keyslot data */
+ struct blk_ksm_keyslot *slots;
+};
+
+int blk_ksm_init(struct blk_keyslot_manager *ksm, unsigned int num_slots);
+
+blk_status_t blk_ksm_get_slot_for_key(struct blk_keyslot_manager *ksm,
+ const struct blk_crypto_key *key,
+ struct blk_ksm_keyslot **slot_ptr);
+
+unsigned int blk_ksm_get_slot_idx(struct blk_ksm_keyslot *slot);
+
+void blk_ksm_put_slot(struct blk_ksm_keyslot *slot);
+
+bool blk_ksm_crypto_cfg_supported(struct blk_keyslot_manager *ksm,
+ const struct blk_crypto_config *cfg);
+
+int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
+ const struct blk_crypto_key *key);
+
+void blk_ksm_reprogram_all_keys(struct blk_keyslot_manager *ksm);
+
+void blk_ksm_destroy(struct blk_keyslot_manager *ksm);
+
+#endif /* __LINUX_KEYSLOT_MANAGER_H */