/*
 * linux/drivers/s390/crypto/ap_bus.h
 *
 * Copyright (C) 2006 IBM Corporation
 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *            Martin Schwidefsky <schwidefsky@de.ibm.com>
 *            Ralph Wuerthner <rwuerthn@de.ibm.com>
 *            Felix Beck <felix.beck@de.ibm.com>
 *            Holger Dengler <hd@linux.vnet.ibm.com>
 *
 * Adjunct processor bus header file.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef _AP_BUS_H_
#define _AP_BUS_H_

#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/types.h>

#define AP_DEVICES 64           /* Number of AP devices. */
#define AP_DOMAINS 16           /* Number of AP domains. */
#define AP_MAX_RESET 90         /* Maximum number of resets. */
#define AP_RESET_TIMEOUT (HZ/2) /* Time in ticks for reset timeouts. */
#define AP_CONFIG_TIME 30       /* Time in seconds between AP bus rescans. */
#define AP_POLL_TIME 1          /* Time in ticks between receive polls. */

extern int ap_domain_index;

/**
 * The ap_qid_t identifier of an ap queue. It contains a
 * 6 bit device index and a 4 bit queue index (domain).
 */
typedef unsigned int ap_qid_t;

#define AP_MKQID(_device,_queue) (((_device) & 63) << 8 | ((_queue) & 15))
#define AP_QID_DEVICE(_qid) (((_qid) >> 8) & 63)
#define AP_QID_QUEUE(_qid) ((_qid) & 15)

/**
 * structy ap_queue_status - Holds the AP queue status.
 * @queue_empty: Shows if queue is empty
 * @replies_waiting: Waiting replies
 * @queue_full: Is 1 if the queue is full
 * @pad: A 4 bit pad
 * @int_enabled: Shows if interrupts are enabled for the AP
 * @response_conde: Holds the 8 bit response code
 * @pad2: A 16 bit pad
 *
 * The ap queue status word is returned by all three AP functions
 * (PQAP, NQAP and DQAP).  There's a set of flags in the first
 * byte, followed by a 1 byte response code.
 */
struct ap_queue_status {
        unsigned int queue_empty        : 1;
        unsigned int replies_waiting    : 1;
        unsigned int queue_full         : 1;
        unsigned int pad1               : 4;
        unsigned int int_enabled        : 1;
        unsigned int response_code      : 8;
        unsigned int pad2               : 16;
} __packed;

#define AP_QUEUE_STATUS_INVALID \
                { 1, 1, 1, 0xF, 1, 0xFF, 0xFFFF }

static inline
int ap_queue_status_invalid_test(struct ap_queue_status *status)
{
        struct ap_queue_status invalid = AP_QUEUE_STATUS_INVALID;
        return !(memcmp(status, &invalid, sizeof(struct ap_queue_status)));
}

#define MAX_AP_FACILITY 31

static inline int test_ap_facility(unsigned int function, unsigned int nr)
{
        if (nr > MAX_AP_FACILITY)
                return 0;
        return function & (unsigned int)(0x80000000 >> nr);
}

#define AP_RESPONSE_NORMAL              0x00
#define AP_RESPONSE_Q_NOT_AVAIL         0x01
#define AP_RESPONSE_RESET_IN_PROGRESS   0x02
#define AP_RESPONSE_DECONFIGURED        0x03
#define AP_RESPONSE_CHECKSTOPPED        0x04
#define AP_RESPONSE_BUSY                0x05
#define AP_RESPONSE_INVALID_ADDRESS     0x06
#define AP_RESPONSE_OTHERWISE_CHANGED   0x07
#define AP_RESPONSE_Q_FULL              0x10
#define AP_RESPONSE_NO_PENDING_REPLY    0x10
#define AP_RESPONSE_INDEX_TOO_BIG       0x11
#define AP_RESPONSE_NO_FIRST_PART       0x13
#define AP_RESPONSE_MESSAGE_TOO_BIG     0x15
#define AP_RESPONSE_REQ_FAC_NOT_INST    0x16

/*
 * Known device types
 */
#define AP_DEVICE_TYPE_PCICC    3
#define AP_DEVICE_TYPE_PCICA    4
#define AP_DEVICE_TYPE_PCIXCC   5
#define AP_DEVICE_TYPE_CEX2A    6
#define AP_DEVICE_TYPE_CEX2C    7
#define AP_DEVICE_TYPE_CEX3A    8
#define AP_DEVICE_TYPE_CEX3C    9

/*
 * AP reset flag states
 */
#define AP_RESET_IGNORE 0       /* request timeout will be ignored */
#define AP_RESET_ARMED  1       /* request timeout timer is active */
#define AP_RESET_DO     2       /* AP reset required */

struct ap_device;
struct ap_message;

struct ap_driver {
        struct device_driver driver;
        struct ap_device_id *ids;

        int (*probe)(struct ap_device *);
        void (*remove)(struct ap_device *);
        /* receive is called from tasklet context */
        void (*receive)(struct ap_device *, struct ap_message *,
                        struct ap_message *);
        int request_timeout;            /* request timeout in jiffies */
};

#define to_ap_drv(x) container_of((x), struct ap_driver, driver)

int ap_driver_register(struct ap_driver *, struct module *, char *);
void ap_driver_unregister(struct ap_driver *);

struct ap_device {
        struct device device;
        struct ap_driver *drv;          /* Pointer to AP device driver. */
        spinlock_t lock;                /* Per device lock. */
        struct list_head list;          /* private list of all AP devices. */

        ap_qid_t qid;                   /* AP queue id. */
        int queue_depth;                /* AP queue depth.*/
        int device_type;                /* AP device type. */
        int unregistered;               /* marks AP device as unregistered */
        struct timer_list timeout;      /* Timer for request timeouts. */
        int reset;                      /* Reset required after req. timeout. */

        int queue_count;                /* # messages currently on AP queue. */

        struct list_head pendingq;      /* List of message sent to AP queue. */
        int pendingq_count;             /* # requests on pendingq list. */
        struct list_head requestq;      /* List of message yet to be sent. */
        int requestq_count;             /* # requests on requestq list. */
        int total_request_count;        /* # requests ever for this AP device. */

        struct ap_message *reply;       /* Per device reply message. */

        void *private;                  /* ap driver private pointer. */
};

#define to_ap_dev(x) container_of((x), struct ap_device, device)

struct ap_message {
        struct list_head list;          /* Request queueing. */
        unsigned long long psmid;       /* Message id. */
        void *message;                  /* Pointer to message buffer. */
        size_t length;                  /* Message length. */

        void *private;                  /* ap driver private pointer. */
        unsigned int special:1;         /* Used for special commands. */
};

#define AP_DEVICE(dt)                                   \
        .dev_type=(dt),                                 \
        .match_flags=AP_DEVICE_ID_MATCH_DEVICE_TYPE,

/**
 * ap_init_message() - Initialize ap_message.
 * Initialize a message before using. Otherwise this might result in
 * unexpected behaviour.
 */
static inline void ap_init_message(struct ap_message *ap_msg)
{
        ap_msg->psmid = 0;
        ap_msg->length = 0;
        ap_msg->special = 0;
}

/*
 * Note: don't use ap_send/ap_recv after using ap_queue_message
 * for the first time. Otherwise the ap message queue will get
 * confused.
 */
int ap_send(ap_qid_t, unsigned long long, void *, size_t);
int ap_recv(ap_qid_t, unsigned long long *, void *, size_t);

void ap_queue_message(struct ap_device *ap_dev, struct ap_message *ap_msg);
void ap_cancel_message(struct ap_device *ap_dev, struct ap_message *ap_msg);
void ap_flush_queue(struct ap_device *ap_dev);

int ap_module_init(void);
void ap_module_exit(void);

int ap_4096_commands_available(ap_qid_t qid);

#endif /* _AP_BUS_H_ */