/*
 * Copyright 2016 Broadcom
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation (the "GPL").
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 (GPLv2) for more details.
 *
 * You should have received a copy of the GNU General Public License
 * version 2 (GPLv2) along with this source code.
 */

#ifndef _CIPHER_H
#define _CIPHER_H

#include <linux/atomic.h>
#include <linux/mailbox/brcm-message.h>
#include <linux/mailbox_client.h>
#include <crypto/aes.h>
#include <crypto/internal/hash.h>
#include <crypto/aead.h>
#include <crypto/gcm.h>
#include <crypto/sha.h>
#include <crypto/sha3.h>

#include "spu.h"
#include "spum.h"
#include "spu2.h"

/* Driver supports up to MAX_SPUS SPU blocks */
#define MAX_SPUS 16

#define ARC4_MIN_KEY_SIZE   1
#define ARC4_MAX_KEY_SIZE   256
#define ARC4_BLOCK_SIZE     1
#define ARC4_STATE_SIZE     4

#define CCM_AES_IV_SIZE    16
#define CCM_ESP_IV_SIZE     8
#define RFC4543_ICV_SIZE   16

#define MAX_KEY_SIZE    ARC4_MAX_KEY_SIZE
#define MAX_IV_SIZE     AES_BLOCK_SIZE
#define MAX_DIGEST_SIZE SHA3_512_DIGEST_SIZE
#define MAX_ASSOC_SIZE  512

/* size of salt value for AES-GCM-ESP and AES-CCM-ESP */
#define GCM_ESP_SALT_SIZE   4
#define CCM_ESP_SALT_SIZE   3
#define MAX_SALT_SIZE       GCM_ESP_SALT_SIZE
#define GCM_ESP_SALT_OFFSET 0
#define CCM_ESP_SALT_OFFSET 1

#define GCM_ESP_DIGESTSIZE 16

#define MAX_HASH_BLOCK_SIZE SHA512_BLOCK_SIZE

/*
 * Maximum number of bytes from a non-final hash request that can be deferred
 * until more data is available. With new crypto API framework, this
 * can be no more than one block of data.
 */
#define HASH_CARRY_MAX  MAX_HASH_BLOCK_SIZE

/* Force at least 4-byte alignment of all SPU message fields */
#define SPU_MSG_ALIGN  4

/* Number of times to resend mailbox message if mb queue is full */
#define SPU_MB_RETRY_MAX  1000

/* op_counts[] indexes */
enum op_type {
        SPU_OP_CIPHER,
        SPU_OP_HASH,
        SPU_OP_HMAC,
        SPU_OP_AEAD,
        SPU_OP_NUM
};

enum spu_spu_type {
        SPU_TYPE_SPUM,
        SPU_TYPE_SPU2,
};

/*
 * SPUM_NS2 and SPUM_NSP are the SPU-M block on Northstar 2 and Northstar Plus,
 * respectively.
 */
enum spu_spu_subtype {
        SPU_SUBTYPE_SPUM_NS2,
        SPU_SUBTYPE_SPUM_NSP,
        SPU_SUBTYPE_SPU2_V1,
        SPU_SUBTYPE_SPU2_V2
};

struct spu_type_subtype {
        enum spu_spu_type type;
        enum spu_spu_subtype subtype;
};

struct cipher_op {
        enum spu_cipher_alg alg;
        enum spu_cipher_mode mode;
};

struct auth_op {
        enum hash_alg alg;
        enum hash_mode mode;
};

struct iproc_alg_s {
        u32 type;
        union {
                struct crypto_alg crypto;
                struct ahash_alg hash;
                struct aead_alg aead;
        } alg;
        struct cipher_op cipher_info;
        struct auth_op auth_info;
        bool auth_first;
        bool registered;
};

/*
 * Buffers for a SPU request/reply message pair. All part of one structure to
 * allow a single alloc per request.
 */
struct spu_msg_buf {
        /* Request message fragments */

        /*
         * SPU request message header. For SPU-M, holds MH, EMH, SCTX, BDESC,
         * and BD header. For SPU2, holds FMD, OMD.
         */
        u8 bcm_spu_req_hdr[ALIGN(SPU2_HEADER_ALLOC_LEN, SPU_MSG_ALIGN)];

        /* IV or counter. Size to include salt. Also used for XTS tweek. */
        u8 iv_ctr[ALIGN(2 * AES_BLOCK_SIZE, SPU_MSG_ALIGN)];

        /* Hash digest. request and response. */
        u8 digest[ALIGN(MAX_DIGEST_SIZE, SPU_MSG_ALIGN)];

        /* SPU request message padding */
        u8 spu_req_pad[ALIGN(SPU_PAD_LEN_MAX, SPU_MSG_ALIGN)];

        /* SPU-M request message STATUS field */
        u8 tx_stat[ALIGN(SPU_TX_STATUS_LEN, SPU_MSG_ALIGN)];

        /* Response message fragments */

        /* SPU response message header */
        u8 spu_resp_hdr[ALIGN(SPU2_HEADER_ALLOC_LEN, SPU_MSG_ALIGN)];

        /* SPU response message STATUS field padding */
        u8 rx_stat_pad[ALIGN(SPU_STAT_PAD_MAX, SPU_MSG_ALIGN)];

        /* SPU response message STATUS field */
        u8 rx_stat[ALIGN(SPU_RX_STATUS_LEN, SPU_MSG_ALIGN)];

        union {
                /* Buffers only used for ablkcipher */
                struct {
                        /*
                         * Field used for either SUPDT when RC4 is used
                         * -OR- tweak value when XTS/AES is used
                         */
                        u8 supdt_tweak[ALIGN(SPU_SUPDT_LEN, SPU_MSG_ALIGN)];
                } c;

                /* Buffers only used for aead */
                struct {
                        /* SPU response pad for GCM data */
                        u8 gcmpad[ALIGN(AES_BLOCK_SIZE, SPU_MSG_ALIGN)];

                        /* SPU request msg padding for GCM AAD */
                        u8 req_aad_pad[ALIGN(SPU_PAD_LEN_MAX, SPU_MSG_ALIGN)];

                        /* SPU response data to be discarded */
                        u8 resp_aad[ALIGN(MAX_ASSOC_SIZE + MAX_IV_SIZE,
                                          SPU_MSG_ALIGN)];
                } a;
        };
};

struct iproc_ctx_s {
        u8 enckey[MAX_KEY_SIZE + ARC4_STATE_SIZE];
        unsigned int enckeylen;

        u8 authkey[MAX_KEY_SIZE + ARC4_STATE_SIZE];
        unsigned int authkeylen;

        u8 salt[MAX_SALT_SIZE];
        unsigned int salt_len;
        unsigned int salt_offset;
        u8 iv[MAX_IV_SIZE];

        unsigned int digestsize;

        struct iproc_alg_s *alg;
        bool is_esp;

        struct cipher_op cipher;
        enum spu_cipher_type cipher_type;

        struct auth_op auth;
        bool auth_first;

        /*
         * The maximum length in bytes of the payload in a SPU message for this
         * context. For SPU-M, the payload is the combination of AAD and data.
         * For SPU2, the payload is just data. A value of SPU_MAX_PAYLOAD_INF
         * indicates that there is no limit to the length of the SPU message
         * payload.
         */
        unsigned int max_payload;

        struct crypto_aead *fallback_cipher;

        /* auth_type is determined during processing of request */

        u8 ipad[MAX_HASH_BLOCK_SIZE];
        u8 opad[MAX_HASH_BLOCK_SIZE];

        /*
         * Buffer to hold SPU message header template. Template is created at
         * setkey time for ablkcipher requests, since most of the fields in the
         * header are known at that time. At request time, just fill in a few
         * missing pieces related to length of data in the request and IVs, etc.
         */
        u8 bcm_spu_req_hdr[ALIGN(SPU2_HEADER_ALLOC_LEN, SPU_MSG_ALIGN)];

        /* Length of SPU request header */
        u16 spu_req_hdr_len;

        /* Expected length of SPU response header */
        u16 spu_resp_hdr_len;

        /*
         * shash descriptor - needed to perform incremental hashing in
         * in software, when hw doesn't support it.
         */
        struct shash_desc *shash;

        bool is_rfc4543;        /* RFC 4543 style of GMAC */
};

/* state from iproc_reqctx_s necessary for hash state export/import */
struct spu_hash_export_s {
        unsigned int total_todo;
        unsigned int total_sent;
        u8 hash_carry[HASH_CARRY_MAX];
        unsigned int hash_carry_len;
        u8 incr_hash[MAX_DIGEST_SIZE];
        bool is_sw_hmac;
};

struct iproc_reqctx_s {
        /* general context */
        struct crypto_async_request *parent;

        /* only valid after enqueue() */
        struct iproc_ctx_s *ctx;

        u8 chan_idx;   /* Mailbox channel to be used to submit this request */

        /* total todo, rx'd, and sent for this request */
        unsigned int total_todo;
        unsigned int total_received;    /* only valid for ablkcipher */
        unsigned int total_sent;

        /*
         * num bytes sent to hw from the src sg in this request. This can differ
         * from total_sent for incremental hashing. total_sent includes previous
         * init() and update() data. src_sent does not.
         */
        unsigned int src_sent;

        /*
         * For AEAD requests, start of associated data. This will typically
         * point to the beginning of the src scatterlist from the request,
         * since assoc data is at the beginning of the src scatterlist rather
         * than in its own sg.
         */
        struct scatterlist *assoc;

        /*
         * scatterlist entry and offset to start of data for next chunk. Crypto
         * API src scatterlist for AEAD starts with AAD, if present. For first
         * chunk, src_sg is sg entry at beginning of input data (after AAD).
         * src_skip begins at the offset in that sg entry where data begins.
         */
        struct scatterlist *src_sg;
        int src_nents;          /* Number of src entries with data */
        u32 src_skip;           /* bytes of current sg entry already used */

        /*
         * Same for destination. For AEAD, if there is AAD, output data must
         * be written at offset following AAD.
         */
        struct scatterlist *dst_sg;
        int dst_nents;          /* Number of dst entries with data */
        u32 dst_skip;           /* bytes of current sg entry already written */

        /* Mailbox message used to send this request to PDC driver */
        struct brcm_message mb_mssg;

        bool bd_suppress;       /* suppress BD field in SPU response? */

        /* cipher context */
        bool is_encrypt;

        /*
         * CBC mode: IV.  CTR mode: counter.  Else empty. Used as a DMA
         * buffer for AEAD requests. So allocate as DMAable memory. If IV
         * concatenated with salt, includes the salt.
         */
        u8 *iv_ctr;
        /* Length of IV or counter, in bytes */
        unsigned int iv_ctr_len;

        /*
         * Hash requests can be of any size, whether initial, update, or final.
         * A non-final request must be submitted to the SPU as an integral
         * number of blocks. This may leave data at the end of the request
         * that is not a full block. Since the request is non-final, it cannot
         * be padded. So, we write the remainder to this hash_carry buffer and
         * hold it until the next request arrives. The carry data is then
         * submitted at the beginning of the data in the next SPU msg.
         * hash_carry_len is the number of bytes currently in hash_carry. These
         * fields are only used for ahash requests.
         */
        u8 hash_carry[HASH_CARRY_MAX];
        unsigned int hash_carry_len;
        unsigned int is_final;  /* is this the final for the hash op? */

        /*
         * Digest from incremental hash is saved here to include in next hash
         * operation. Cannot be stored in req->result for truncated hashes,
         * since result may be sized for final digest. Cannot be saved in
         * msg_buf because that gets deleted between incremental hash ops
         * and is not saved as part of export().
         */
        u8 incr_hash[MAX_DIGEST_SIZE];

        /* hmac context */
        bool is_sw_hmac;

        /* aead context */
        struct crypto_tfm *old_tfm;
        crypto_completion_t old_complete;
        void *old_data;

        gfp_t gfp;

        /* Buffers used to build SPU request and response messages */
        struct spu_msg_buf msg_buf;
};

/*
 * Structure encapsulates a set of function pointers specific to the type of
 * SPU hardware running. These functions handling creation and parsing of
 * SPU request messages and SPU response messages. Includes hardware-specific
 * values read from device tree.
 */
struct spu_hw {
        void (*spu_dump_msg_hdr)(u8 *buf, unsigned int buf_len);
        u32 (*spu_ctx_max_payload)(enum spu_cipher_alg cipher_alg,
                                   enum spu_cipher_mode cipher_mode,
                                   unsigned int blocksize);
        u32 (*spu_payload_length)(u8 *spu_hdr);
        u16 (*spu_response_hdr_len)(u16 auth_key_len, u16 enc_key_len,
                                    bool is_hash);
        u16 (*spu_hash_pad_len)(enum hash_alg hash_alg,
                                enum hash_mode hash_mode, u32 chunksize,
                                u16 hash_block_size);
        u32 (*spu_gcm_ccm_pad_len)(enum spu_cipher_mode cipher_mode,
                                   unsigned int data_size);
        u32 (*spu_assoc_resp_len)(enum spu_cipher_mode cipher_mode,
                                  unsigned int assoc_len,
                                  unsigned int iv_len, bool is_encrypt);
        u8 (*spu_aead_ivlen)(enum spu_cipher_mode cipher_mode,
                             u16 iv_len);
        enum hash_type (*spu_hash_type)(u32 src_sent);
        u32 (*spu_digest_size)(u32 digest_size, enum hash_alg alg,
                               enum hash_type);
        u32 (*spu_create_request)(u8 *spu_hdr,
                                  struct spu_request_opts *req_opts,
                                  struct spu_cipher_parms *cipher_parms,
                                  struct spu_hash_parms *hash_parms,
                                  struct spu_aead_parms *aead_parms,
                                  unsigned int data_size);
        u16 (*spu_cipher_req_init)(u8 *spu_hdr,
                                   struct spu_cipher_parms *cipher_parms);
        void (*spu_cipher_req_finish)(u8 *spu_hdr,
                                      u16 spu_req_hdr_len,
                                      unsigned int is_inbound,
                                      struct spu_cipher_parms *cipher_parms,
                                      bool update_key,
                                      unsigned int data_size);
        void (*spu_request_pad)(u8 *pad_start, u32 gcm_padding,
                                u32 hash_pad_len, enum hash_alg auth_alg,
                                enum hash_mode auth_mode,
                                unsigned int total_sent, u32 status_padding);
        u8 (*spu_xts_tweak_in_payload)(void);
        u8 (*spu_tx_status_len)(void);
        u8 (*spu_rx_status_len)(void);
        int (*spu_status_process)(u8 *statp);
        void (*spu_ccm_update_iv)(unsigned int digestsize,
                                  struct spu_cipher_parms *cipher_parms,
                                  unsigned int assoclen, unsigned int chunksize,
                                  bool is_encrypt, bool is_esp);
        u32 (*spu_wordalign_padlen)(u32 data_size);

        /* The base virtual address of the SPU hw registers */
        void __iomem *reg_vbase[MAX_SPUS];

        /* Version of the SPU hardware */
        enum spu_spu_type spu_type;

        /* Sub-version of the SPU hardware */
        enum spu_spu_subtype spu_subtype;

        /* The number of SPUs on this platform */
        u32 num_spu;

        /* The number of SPU channels on this platform */
        u32 num_chan;
};

struct device_private {
        struct platform_device *pdev;

        struct spu_hw spu;

        atomic_t session_count; /* number of streams active */
        atomic_t stream_count;  /* monotonic counter for streamID's */

        /* Length of BCM header. Set to 0 when hw does not expect BCM HEADER. */
        u8 bcm_hdr_len;

        /* The index of the channel to use for the next crypto request */
        atomic_t next_chan;

        struct dentry *debugfs_dir;
        struct dentry *debugfs_stats;

        /* Number of request bytes processed and result bytes returned */
        atomic64_t bytes_in;
        atomic64_t bytes_out;

        /* Number of operations of each type */
        atomic_t op_counts[SPU_OP_NUM];

        atomic_t cipher_cnt[CIPHER_ALG_LAST][CIPHER_MODE_LAST];
        atomic_t hash_cnt[HASH_ALG_LAST];
        atomic_t hmac_cnt[HASH_ALG_LAST];
        atomic_t aead_cnt[AEAD_TYPE_LAST];

        /* Number of calls to setkey() for each operation type */
        atomic_t setkey_cnt[SPU_OP_NUM];

        /* Number of times request was resubmitted because mb was full */
        atomic_t mb_no_spc;

        /* Number of mailbox send failures */
        atomic_t mb_send_fail;

        /* Number of ICV check failures for AEAD messages */
        atomic_t bad_icv;

        struct mbox_client mcl;

        /* Array of mailbox channel pointers, one for each channel */
        struct mbox_chan **mbox;
};

extern struct device_private iproc_priv;

#endif