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>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/s390/char/sclp_rw.h b/drivers/s390/char/sclp_rw.h
index 7a7bfc947d97..e3b0290995ba 100644
--- a/drivers/s390/char/sclp_rw.h
+++ b/drivers/s390/char/sclp_rw.h
@@ -45,6 +45,7 @@ struct mdb_header {
 struct mdb {
 	struct mdb_header header;
 	struct go go;
+	struct mto mto;
 } __attribute__((packed));
 
 struct msg_buf {
@@ -52,14 +53,9 @@ struct msg_buf {
 	struct mdb mdb;
 } __attribute__((packed));
 
-struct write_sccb {
-	struct sccb_header header;
-	struct msg_buf msg_buf;
-} __attribute__((packed));
-
 /* The number of empty mto buffers that can be contained in a single sccb. */
-#define NR_EMPTY_MTO_PER_SCCB ((PAGE_SIZE - sizeof(struct sclp_buffer) - \
-			sizeof(struct write_sccb)) / sizeof(struct mto))
+#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),
@@ -68,7 +64,8 @@ struct write_sccb {
 struct sclp_buffer {
 	struct list_head list;		/* list_head for sccb_info chain */
 	struct sclp_req request;
-	struct write_sccb *sccb;
+	void *sccb;
+	struct msg_buf *current_msg;
 	char *current_line;
 	int current_length;
 	int retry_count;
@@ -76,8 +73,8 @@ struct sclp_buffer {
 	unsigned short columns;
 	unsigned short htab;
 	/* statistics about this buffer */
-	unsigned int mto_char_sum;	/* # chars in sccb */
-	unsigned int mto_number;	/* # mtos in sccb */
+	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);
 };