linux/drivers/s390/char/sclp_rw.h
Martin Schwidefsky 18d1a7f675 s390/sclp: avoid merged message output
The sclp console and tty code currently uses several message text
objects in a single message event to print several lines with one
SCCB. This causes the output of these lines to be fused into a
block which is noticeable when selecting text in the operating system
message panel.

Instead use several message events with a single message text object
each to print every line on its own. This changes the SCCB layout
from

    struct sccb_header
        struct evbuf_header
            struct mdb_header
                struct go
                struct mto
		...
		struct mto

to

    struct sccb_header
        struct evbuf_header
            struct mdb_header
                struct go
                struct mto
	...
        struct evbuf_header
            struct mdb_header
                struct go
                struct mto

Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14 14:32:10 +02:00

99 lines
2.5 KiB
C

/*
* 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));
void sclp_set_columns(struct sclp_buffer *, unsigned short);
void sclp_set_htab(struct sclp_buffer *, unsigned short);
int sclp_chars_in_buffer(struct sclp_buffer *);
#ifdef CONFIG_SCLP_CONSOLE
void sclp_console_pm_event(enum sclp_pm_event sclp_pm_event);
#else
static inline void sclp_console_pm_event(enum sclp_pm_event sclp_pm_event) { }
#endif
#endif /* __SCLP_RW_H__ */