/*
 * Channel subsystem structures and definitions.
 *
 * Copyright 2012 IBM Corp.
 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or (at
 * your option) any later version. See the COPYING file in the top-level
 * directory.
 */

#ifndef CSS_H
#define CSS_H

#include "cpu.h"
#include "hw/s390x/adapter.h"
#include "hw/s390x/s390_flic.h"
#include "hw/s390x/ioinst.h"
#include "sysemu/kvm.h"

/* Channel subsystem constants. */
#define MAX_DEVNO 65535
#define MAX_SCHID 65535
#define MAX_SSID 3
#define MAX_CSSID 255
#define MAX_CHPID 255

#define MAX_ISC 7

#define MAX_CIWS 62

#define VIRTUAL_CSSID 0xfe
#define VIRTIO_CCW_CHPID 0   /* used by convention */

typedef struct CIW {
    uint8_t type;
    uint8_t command;
    uint16_t count;
} QEMU_PACKED CIW;

typedef struct SenseId {
    /* common part */
    uint8_t reserved;        /* always 0x'FF' */
    uint16_t cu_type;        /* control unit type */
    uint8_t cu_model;        /* control unit model */
    uint16_t dev_type;       /* device type */
    uint8_t dev_model;       /* device model */
    uint8_t unused;          /* padding byte */
    /* extended part */
    CIW ciw[MAX_CIWS];       /* variable # of CIWs */
} SenseId;                   /* Note: No QEMU_PACKED due to unaligned members */

/* Channel measurements, from linux/drivers/s390/cio/cmf.c. */
typedef struct CMB {
    uint16_t ssch_rsch_count;
    uint16_t sample_count;
    uint32_t device_connect_time;
    uint32_t function_pending_time;
    uint32_t device_disconnect_time;
    uint32_t control_unit_queuing_time;
    uint32_t device_active_only_time;
    uint32_t reserved[2];
} QEMU_PACKED CMB;

typedef struct CMBE {
    uint32_t ssch_rsch_count;
    uint32_t sample_count;
    uint32_t device_connect_time;
    uint32_t function_pending_time;
    uint32_t device_disconnect_time;
    uint32_t control_unit_queuing_time;
    uint32_t device_active_only_time;
    uint32_t device_busy_time;
    uint32_t initial_command_response_time;
    uint32_t reserved[7];
} QEMU_PACKED CMBE;

typedef enum CcwDataStreamOp {
    CDS_OP_R = 0, /* read, false when used as is_write */
    CDS_OP_W = 1, /* write, true when used as is_write */
    CDS_OP_A = 2  /* advance, should not be used as is_write */
} CcwDataStreamOp;

/* normal usage is via SuchchDev.cds instead of instantiating */
typedef struct CcwDataStream {
#define CDS_F_IDA   0x01
#define CDS_F_MIDA  0x02
#define CDS_F_I2K   0x04
#define CDS_F_C64   0x08
#define CDS_F_FMT   0x10 /* CCW format-1 */
#define CDS_F_STREAM_BROKEN  0x80
    uint8_t flags;
    uint8_t at_idaw;
    uint16_t at_byte;
    uint16_t count;
    uint32_t cda_orig;
    int (*op_handler)(struct CcwDataStream *cds, void *buff, int len,
                      CcwDataStreamOp op);
    hwaddr cda;
} CcwDataStream;

/*
 * IO instructions conclude according to this. Currently we have only
 * cc codes. Valid values are 0, 1, 2, 3 and the generic semantic for
 * IO instructions is described briefly. For more details consult the PoP.
 */
typedef enum IOInstEnding {
    /* produced expected result */
    IOINST_CC_EXPECTED = 0,
    /* status conditions were present or produced alternate result */
    IOINST_CC_STATUS_PRESENT = 1,
    /* inst. ineffective because busy with previously initiated function */
    IOINST_CC_BUSY = 2,
    /* inst. ineffective because not operational */
    IOINST_CC_NOT_OPERATIONAL = 3
} IOInstEnding;

typedef struct SubchDev SubchDev;
struct SubchDev {
    /* channel-subsystem related things: */
    SCHIB curr_status;           /* Needs alignment and thus must come first */
    ORB orb;
    uint8_t cssid;
    uint8_t ssid;
    uint16_t schid;
    uint16_t devno;
    uint8_t sense_data[32];
    hwaddr channel_prog;
    CCW1 last_cmd;
    bool last_cmd_valid;
    bool ccw_fmt_1;
    bool thinint_active;
    uint8_t ccw_no_data_cnt;
    uint16_t migrated_schid; /* used for missmatch detection */
    CcwDataStream cds;
    /* transport-provided data: */
    int (*ccw_cb) (SubchDev *, CCW1);
    void (*disable_cb)(SubchDev *);
    IOInstEnding (*do_subchannel_work) (SubchDev *);
    SenseId id;
    void *driver_data;
};

static inline void sch_gen_unit_exception(SubchDev *sch)
{
    sch->curr_status.scsw.ctrl &= ~SCSW_ACTL_START_PEND;
    sch->curr_status.scsw.ctrl |= SCSW_STCTL_PRIMARY |
                                  SCSW_STCTL_SECONDARY |
                                  SCSW_STCTL_ALERT |
                                  SCSW_STCTL_STATUS_PEND;
    sch->curr_status.scsw.cpa = sch->channel_prog + 8;
    sch->curr_status.scsw.dstat =  SCSW_DSTAT_UNIT_EXCEP;
}

extern const VMStateDescription vmstate_subch_dev;

/*
 * Identify a device within the channel subsystem.
 * Note that this can be used to identify either the subchannel or
 * the attached I/O device, as there's always one I/O device per
 * subchannel.
 */
typedef struct CssDevId {
    uint8_t cssid;
    uint8_t ssid;
    uint16_t devid;
    bool valid;
} CssDevId;

extern const PropertyInfo css_devid_propinfo;

#define DEFINE_PROP_CSS_DEV_ID(_n, _s, _f) \
    DEFINE_PROP(_n, _s, _f, css_devid_propinfo, CssDevId)

typedef struct IndAddr {
    hwaddr addr;
    uint64_t map;
    unsigned long refcnt;
    int32_t len;
    QTAILQ_ENTRY(IndAddr) sibling;
} IndAddr;

extern const VMStateDescription vmstate_ind_addr;

#define VMSTATE_PTR_TO_IND_ADDR(_f, _s)                                   \
    VMSTATE_STRUCT(_f, _s, 1, vmstate_ind_addr, IndAddr*)

IndAddr *get_indicator(hwaddr ind_addr, int len);
void release_indicator(AdapterInfo *adapter, IndAddr *indicator);
int map_indicator(AdapterInfo *adapter, IndAddr *indicator);

typedef SubchDev *(*css_subch_cb_func)(uint8_t m, uint8_t cssid, uint8_t ssid,
                                       uint16_t schid);
int css_create_css_image(uint8_t cssid, bool default_image);
bool css_devno_used(uint8_t cssid, uint8_t ssid, uint16_t devno);
void css_subch_assign(uint8_t cssid, uint8_t ssid, uint16_t schid,
                      uint16_t devno, SubchDev *sch);
void css_sch_build_virtual_schib(SubchDev *sch, uint8_t chpid, uint8_t type);
int css_sch_build_schib(SubchDev *sch, CssDevId *dev_id);
unsigned int css_find_free_chpid(uint8_t cssid);
uint16_t css_build_subchannel_id(SubchDev *sch);
void copy_scsw_to_guest(SCSW *dest, const SCSW *src);
void css_inject_io_interrupt(SubchDev *sch);
void css_reset(void);
void css_reset_sch(SubchDev *sch);
void css_queue_crw(uint8_t rsc, uint8_t erc, int solicited,
                   int chain, uint16_t rsid);
void css_generate_sch_crws(uint8_t cssid, uint8_t ssid, uint16_t schid,
                           int hotplugged, int add);
void css_generate_chp_crws(uint8_t cssid, uint8_t chpid);
void css_generate_css_crws(uint8_t cssid);
void css_clear_sei_pending(void);
IOInstEnding s390_ccw_cmd_request(SubchDev *sch);
IOInstEnding do_subchannel_work_virtual(SubchDev *sub);
IOInstEnding do_subchannel_work_passthrough(SubchDev *sub);

typedef enum {
    CSS_IO_ADAPTER_VIRTIO = 0,
    CSS_IO_ADAPTER_PCI = 1,
    CSS_IO_ADAPTER_TYPE_NUMS,
} CssIoAdapterType;

void css_adapter_interrupt(CssIoAdapterType type, uint8_t isc);
int css_do_sic(CPUS390XState *env, uint8_t isc, uint16_t mode);
uint32_t css_get_adapter_id(CssIoAdapterType type, uint8_t isc);
void css_register_io_adapters(CssIoAdapterType type, bool swap, bool maskable,
                              uint8_t flags, Error **errp);

#ifndef CONFIG_KVM
#define S390_ADAPTER_SUPPRESSIBLE 0x01
#else
#define S390_ADAPTER_SUPPRESSIBLE KVM_S390_ADAPTER_SUPPRESSIBLE
#endif

#ifndef CONFIG_USER_ONLY
SubchDev *css_find_subch(uint8_t m, uint8_t cssid, uint8_t ssid,
                         uint16_t schid);
bool css_subch_visible(SubchDev *sch);
void css_conditional_io_interrupt(SubchDev *sch);
int css_do_stsch(SubchDev *sch, SCHIB *schib);
bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid);
IOInstEnding css_do_msch(SubchDev *sch, const SCHIB *schib);
IOInstEnding css_do_xsch(SubchDev *sch);
IOInstEnding css_do_csch(SubchDev *sch);
IOInstEnding css_do_hsch(SubchDev *sch);
IOInstEnding css_do_ssch(SubchDev *sch, ORB *orb);
int css_do_tsch_get_irb(SubchDev *sch, IRB *irb, int *irb_len);
void css_do_tsch_update_subch(SubchDev *sch);
int css_do_stcrw(CRW *crw);
void css_undo_stcrw(CRW *crw);
int css_collect_chp_desc(int m, uint8_t cssid, uint8_t f_chpid, uint8_t l_chpid,
                         int rfmt, void *buf);
void css_do_schm(uint8_t mbk, int update, int dct, uint64_t mbo);
int css_enable_mcsse(void);
int css_enable_mss(void);
IOInstEnding css_do_rsch(SubchDev *sch);
int css_do_rchp(uint8_t cssid, uint8_t chpid);
bool css_present(uint8_t cssid);
#endif

extern const PropertyInfo css_devid_ro_propinfo;

#define DEFINE_PROP_CSS_DEV_ID_RO(_n, _s, _f) \
    DEFINE_PROP(_n, _s, _f, css_devid_ro_propinfo, CssDevId)

/**
 * Create a subchannel for the given bus id.
 *
 * If @p bus_id is valid, verify that it is not already in use, and find a
 * free devno for it.
 * If @p bus_id is not valid find a free subchannel id and device number
 * across all subchannel sets and all css images starting from the default
 * css image.
 *
 * If either of the former actions succeed, allocate a subchannel structure,
 * initialise it with the bus id, subchannel id and device number, register
 * it with the CSS and return it. Otherwise return NULL.
 *
 * The caller becomes owner of the returned subchannel structure and
 * is responsible for unregistering and freeing it.
 */
SubchDev *css_create_sch(CssDevId bus_id, Error **errp);

/** Turn on css migration */
void css_register_vmstate(void);


void ccw_dstream_init(CcwDataStream *cds, CCW1 const *ccw, ORB const *orb);

static inline void ccw_dstream_rewind(CcwDataStream *cds)
{
    cds->at_byte = 0;
    cds->at_idaw = 0;
    cds->cda = cds->cda_orig;
}

static inline bool ccw_dstream_good(CcwDataStream *cds)
{
    return !(cds->flags & CDS_F_STREAM_BROKEN);
}

static inline uint16_t ccw_dstream_residual_count(CcwDataStream *cds)
{
    return cds->count - cds->at_byte;
}

static inline uint16_t ccw_dstream_avail(CcwDataStream *cds)
{
    return ccw_dstream_good(cds) ? ccw_dstream_residual_count(cds) : 0;
}

static inline int ccw_dstream_advance(CcwDataStream *cds, int len)
{
    return cds->op_handler(cds, NULL, len, CDS_OP_A);
}

static inline int ccw_dstream_write_buf(CcwDataStream *cds, void *buff, int len)
{
    return cds->op_handler(cds, buff, len, CDS_OP_W);
}

static inline int ccw_dstream_read_buf(CcwDataStream *cds, void *buff, int len)
{
    return cds->op_handler(cds, buff, len, CDS_OP_R);
}

#define ccw_dstream_read(cds, v) ccw_dstream_read_buf((cds), &(v), sizeof(v))
#define ccw_dstream_write(cds, v) ccw_dstream_write_buf((cds), &(v), sizeof(v))

#endif