1 files changed, 106 insertions, 0 deletions
diff --git a/include/linux/keyslot-manager.h b/include/linux/keyslot-manager.h
new file mode 100644
index 000000000000..18f3f5346843
--- /dev/null
+++ b/include/linux/keyslot-manager.h
@@ -0,0 +1,106 @@
+/* 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 */