/* SPDX-License-Identifier: GPL-2.0 */
  /*
   * Copyright 2019 Google LLC
   */
  
  #ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
  #define __LINUX_BLK_CRYPTO_INTERNAL_H
  
  #include <linux/bio.h>
  #include <linux/blkdev.h>
  
  /* Represents a crypto mode supported by blk-crypto  */
  struct blk_crypto_mode {

  	const char *cipher_str; /* crypto API name (for fallback case) */

  	unsigned int keysize; /* key size in bytes */
  	unsigned int ivsize; /* iv size in bytes */
  };

  extern const struct blk_crypto_mode blk_crypto_modes[];

  #ifdef CONFIG_BLK_INLINE_ENCRYPTION
  
  void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
  			     unsigned int inc);
  
  bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
  
  bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
  			     struct bio_crypt_ctx *bc2);
  
  static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
  						struct bio *bio)
  {
  	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
  				       bio->bi_crypt_context);
  }
  
  static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
  						 struct bio *bio)
  {
  	return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
  				       bio->bi_iter.bi_size, req->crypt_ctx);
  }
  
  static inline bool bio_crypt_ctx_merge_rq(struct request *req,
  					  struct request *next)
  {
  	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
  				       next->crypt_ctx);
  }
  
  static inline void blk_crypto_rq_set_defaults(struct request *rq)
  {
  	rq->crypt_ctx = NULL;
  	rq->crypt_keyslot = NULL;
  }
  
  static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
  {
  	return rq->crypt_ctx;
  }
  
  #else /* CONFIG_BLK_INLINE_ENCRYPTION */
  
  static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
  					       struct bio *bio)
  {
  	return true;
  }
  
  static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
  						 struct bio *bio)
  {
  	return true;
  }
  
  static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
  						struct bio *bio)
  {
  	return true;
  }
  
  static inline bool bio_crypt_ctx_merge_rq(struct request *req,
  					  struct request *next)
  {
  	return true;
  }
  
  static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
  
  static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
  {
  	return false;
  }
  
  #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
  
  void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
  static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
  {
  	if (bio_has_crypt_ctx(bio))
  		__bio_crypt_advance(bio, bytes);
  }
  
  void __bio_crypt_free_ctx(struct bio *bio);
  static inline void bio_crypt_free_ctx(struct bio *bio)
  {
  	if (bio_has_crypt_ctx(bio))
  		__bio_crypt_free_ctx(bio);
  }
  
  static inline void bio_crypt_do_front_merge(struct request *rq,
  					    struct bio *bio)
  {
  #ifdef CONFIG_BLK_INLINE_ENCRYPTION
  	if (bio_has_crypt_ctx(bio))
  		memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
  		       sizeof(rq->crypt_ctx->bc_dun));
  #endif
  }
  
  bool __blk_crypto_bio_prep(struct bio **bio_ptr);
  static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
  {
  	if (bio_has_crypt_ctx(*bio_ptr))
  		return __blk_crypto_bio_prep(bio_ptr);
  	return true;
  }
  
  blk_status_t __blk_crypto_init_request(struct request *rq);
  static inline blk_status_t blk_crypto_init_request(struct request *rq)
  {
  	if (blk_crypto_rq_is_encrypted(rq))
  		return __blk_crypto_init_request(rq);
  	return BLK_STS_OK;
  }
  
  void __blk_crypto_free_request(struct request *rq);
  static inline void blk_crypto_free_request(struct request *rq)
  {
  	if (blk_crypto_rq_is_encrypted(rq))
  		__blk_crypto_free_request(rq);
  }

  int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
  			     gfp_t gfp_mask);
  /**
   * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
   *			    is inserted
   * @rq: The request to prepare
   * @bio: The first bio being inserted into the request
   * @gfp_mask: Memory allocation flags
   *
   * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
   *	   @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
   */
  static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
  					 gfp_t gfp_mask)

  {
  	if (bio_has_crypt_ctx(bio))

  		return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
  	return 0;

  }
  
  /**
   * blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted
   *				      into a request queue.
   * @rq: the request being queued
   *
   * Return: BLK_STS_OK on success, nonzero on error.
   */
  static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
  {
  
  	if (blk_crypto_rq_is_encrypted(rq))
  		return blk_crypto_init_request(rq);
  	return BLK_STS_OK;
  }

  #ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
  
  int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
  
  bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
  
  int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
  
  #else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
  
  static inline int
  blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
  {
  	pr_warn_once("crypto API fallback is disabled
  ");
  	return -ENOPKG;
  }
  
  static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
  {
  	pr_warn_once("crypto API fallback disabled; failing request.
  ");
  	(*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
  	return false;
  }
  
  static inline int
  blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
  {
  	return 0;
  }
  
  #endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */

  #endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */