/* SPDX-License-Identifier: GPL-2.0 */
/*
 * interface to the SCLP-read/write driver
 *
 * Copyright IBM Corporation 1999, 2009
 *
 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
 *            Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#ifndef __SCLP_RW_H__
#define __SCLP_RW_H__

#include <linux/list.h>

struct mto {
        u16 length;
        u16 type;
        u16 line_type_flags;
        u8  alarm_control;
        u8  _reserved[3];
} __attribute__((packed));

struct go {
        u16 length;
        u16 type;
        u32 domid;
        u8  hhmmss_time[8];
        u8  th_time[3];
        u8  reserved_0;
        u8  dddyyyy_date[7];
        u8  _reserved_1;
        u16 general_msg_flags;
        u8  _reserved_2[10];
        u8  originating_system_name[8];
        u8  job_guest_name[8];
} __attribute__((packed));

struct mdb_header {
        u16 length;
        u16 type;
        u32 tag;
        u32 revision_code;
} __attribute__((packed));

struct mdb {
        struct mdb_header header;
        struct go go;
        struct mto mto;
} __attribute__((packed));

struct msg_buf {
        struct evbuf_header header;
        struct mdb mdb;
} __attribute__((packed));

/* The number of empty mto buffers that can be contained in a single sccb. */
#define NR_EMPTY_MSG_PER_SCCB ((PAGE_SIZE - sizeof(struct sclp_buffer) - \
                        sizeof(struct sccb_header)) / sizeof(struct msg_buf))

/*
 * data structure for information about list of SCCBs (only for writing),
 * will be located at the end of a SCCBs page
 */
struct sclp_buffer {
        struct list_head list;          /* list_head for sccb_info chain */
        struct sclp_req request;
        void *sccb;
        struct msg_buf *current_msg;
        char *current_line;
        int current_length;
        int retry_count;
        /* output format settings */
        unsigned short columns;
        unsigned short htab;
        /* statistics about this buffer */
        unsigned int char_sum;          /* # chars in sccb */
        unsigned int messages;          /* # messages in sccb */
        /* Callback that is called after reaching final status. */
        void (*callback)(struct sclp_buffer *, int);
};

int sclp_rw_init(void);
struct sclp_buffer *sclp_make_buffer(void *, unsigned short, unsigned short);
void *sclp_unmake_buffer(struct sclp_buffer *);
int sclp_buffer_space(struct sclp_buffer *);
int sclp_write(struct sclp_buffer *buffer, const unsigned char *, int);
int sclp_emit_buffer(struct sclp_buffer *,void (*)(struct sclp_buffer *,int));
unsigned int sclp_chars_in_buffer(struct sclp_buffer *);

#endif  /* __SCLP_RW_H__ */