/* SPDX-License-Identifier: GPL-2.0+ */
/*
 *  Copyright IBM Corp. 2001, 2019
 *  Author(s): Robert Burroughs
 *             Eric Rossman (edrossma@us.ibm.com)
 *             Cornelia Huck <cornelia.huck@de.ibm.com>
 *
 *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
 *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
 *                                Ralph Wuerthner <rwuerthn@de.ibm.com>
 *  MSGTYPE restruct:             Holger Dengler <hd@linux.vnet.ibm.com>
 */

#ifndef _ZCRYPT_API_H_
#define _ZCRYPT_API_H_

#include <linux/atomic.h>
#include <asm/debug.h>
#include <asm/zcrypt.h>
#include "ap_bus.h"

/**
 * Supported device types
 */
#define ZCRYPT_CEX2C            5
#define ZCRYPT_CEX2A            6
#define ZCRYPT_CEX3C            7
#define ZCRYPT_CEX3A            8
#define ZCRYPT_CEX4            10
#define ZCRYPT_CEX5            11
#define ZCRYPT_CEX6            12
#define ZCRYPT_CEX7            13

/**
 * Large random numbers are pulled in 4096 byte chunks from the crypto cards
 * and stored in a page. Be careful when increasing this buffer due to size
 * limitations for AP requests.
 */
#define ZCRYPT_RNG_BUFFER_SIZE  4096

/**
 * The zcrypt_wait_api_operational() function waits this
 * amount in milliseconds for ap_wait_aqpn_bindings_complete().
 * Also on a cprb send failure with ENODEV the send functions
 * trigger an ap bus rescan and wait this time in milliseconds
 * for ap_wait_aqpn_bindings_complete() before resending.
 */
#define ZCRYPT_WAIT_BINDINGS_COMPLETE_MS 30000

/*
 * Identifier for Crypto Request Performance Index
 */
enum crypto_ops {
        MEX_1K,
        MEX_2K,
        MEX_4K,
        CRT_1K,
        CRT_2K,
        CRT_4K,
        HWRNG,
        SECKEY,
        NUM_OPS
};

struct zcrypt_queue;

/* struct to hold tracking information for a userspace request/response */
struct zcrypt_track {
        int again_counter;              /* retry attempts counter */
        int last_qid;                   /* last qid used */
        int last_rc;                    /* last return code */
};

/* defines related to message tracking */
#define TRACK_AGAIN_MAX 10
#define TRACK_AGAIN_CARD_WEIGHT_PENALTY  1000
#define TRACK_AGAIN_QUEUE_WEIGHT_PENALTY 10000

/*
 * xflags - to be used with zcrypt_send_cprb() and
 * zcrypt_send_ep11_cprb() for the xflags parameter.
 */
#define ZCRYPT_XFLAG_USERSPACE  0x0001  /* data ptrs address userspace */
#define ZCRYPT_XFLAG_NOMEMALLOC 0x0002  /* do not allocate memory via kmalloc */

struct zcrypt_ops {
        long (*rsa_modexpo)(struct zcrypt_queue *, struct ica_rsa_modexpo *,
                            struct ap_message *);
        long (*rsa_modexpo_crt)(struct zcrypt_queue *,
                                struct ica_rsa_modexpo_crt *,
                                struct ap_message *);
        long (*send_cprb)(bool userspace, struct zcrypt_queue *, struct ica_xcRB *,
                          struct ap_message *);
        long (*send_ep11_cprb)(bool userspace, struct zcrypt_queue *, struct ep11_urb *,
                               struct ap_message *);
        long (*rng)(struct zcrypt_queue *, char *, struct ap_message *);
        struct list_head list;          /* zcrypt ops list. */
        struct module *owner;
        int variant;
        char name[128];
};

struct zcrypt_card {
        struct list_head list;          /* Device list. */
        struct list_head zqueues;       /* List of zcrypt queues */
        struct kref refcount;           /* device refcounting */
        struct ap_card *card;           /* The "real" ap card device. */
        int online;                     /* User online/offline */

        int user_space_type;            /* User space device id. */
        char *type_string;              /* User space device name. */
        int min_mod_size;               /* Min number of bits. */
        int max_mod_size;               /* Max number of bits. */
        int max_exp_bit_length;
        const int *speed_rating;        /* Speed idx of crypto ops. */
        atomic_t load;                  /* Utilization of the crypto device */

        int request_count;              /* # current requests. */
};

struct zcrypt_queue {
        struct list_head list;          /* Device list. */
        struct kref refcount;           /* device refcounting */
        struct zcrypt_card *zcard;
        struct zcrypt_ops *ops;         /* Crypto operations. */
        struct ap_queue *queue;         /* The "real" ap queue device. */
        int online;                     /* User online/offline */

        atomic_t load;                  /* Utilization of the crypto device */

        int request_count;              /* # current requests. */

        struct ap_message reply;        /* Per-device reply structure. */
};

/* transport layer rescanning */
extern atomic_t zcrypt_rescan_req;

extern spinlock_t zcrypt_list_lock;
extern struct list_head zcrypt_card_list;

extern unsigned int zcrypt_mempool_threshold;

#define for_each_zcrypt_card(_zc) \
        list_for_each_entry(_zc, &zcrypt_card_list, list)

#define for_each_zcrypt_queue(_zq, _zc) \
        list_for_each_entry(_zq, &(_zc)->zqueues, list)

struct zcrypt_card *zcrypt_card_alloc(void);
void zcrypt_card_free(struct zcrypt_card *);
void zcrypt_card_get(struct zcrypt_card *);
int zcrypt_card_put(struct zcrypt_card *);
int zcrypt_card_register(struct zcrypt_card *);
void zcrypt_card_unregister(struct zcrypt_card *);

struct zcrypt_queue *zcrypt_queue_alloc(size_t);
void zcrypt_queue_free(struct zcrypt_queue *);
void zcrypt_queue_get(struct zcrypt_queue *);
int zcrypt_queue_put(struct zcrypt_queue *);
int zcrypt_queue_register(struct zcrypt_queue *);
void zcrypt_queue_unregister(struct zcrypt_queue *);
bool zcrypt_queue_force_online(struct zcrypt_queue *zq, int online);

int zcrypt_rng_device_add(void);
void zcrypt_rng_device_remove(void);

void zcrypt_msgtype_register(struct zcrypt_ops *);
void zcrypt_msgtype_unregister(struct zcrypt_ops *);
struct zcrypt_ops *zcrypt_msgtype(unsigned char *, int);
int zcrypt_api_init(void);
void zcrypt_api_exit(void);
long zcrypt_send_cprb(struct ica_xcRB *xcRB, u32 xflags);
long zcrypt_send_ep11_cprb(struct ep11_urb *urb, u32 xflags);
void zcrypt_device_status_mask_ext(struct zcrypt_device_status_ext *devstatus,
                                   int maxcard, int maxqueue);
int zcrypt_device_status_ext(int card, int queue,
                             struct zcrypt_device_status_ext *devstatus);

int zcrypt_wait_api_operational(void);

static inline unsigned long z_copy_from_user(bool userspace,
                                             void *to,
                                             const void __user *from,
                                             unsigned long n)
{
        if (likely(userspace))
                return copy_from_user(to, from, n);
        memcpy(to, (void __force *)from, n);
        return 0;
}

static inline unsigned long z_copy_to_user(bool userspace,
                                           void __user *to,
                                           const void *from,
                                           unsigned long n)
{
        if (likely(userspace))
                return copy_to_user(to, from, n);
        memcpy((void __force *)to, from, n);
        return 0;
}

#endif /* _ZCRYPT_API_H_ */