Commit 18d1a7f6 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

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: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 83abeffb

drivers/s390/char/sclp_rw.c

+67 −69
Original line number Diff line number Diff line
@@ -47,9 +47,9 @@ struct sclp_buffer * 
sclp_make_buffer(void *page, unsigned short columns, unsigned short htab)

{

	struct sclp_buffer *buffer;

	struct write_sccb *sccb;

	struct sccb_header *sccb;



	sccb = (struct write_sccb *) page;

	sccb = (struct sccb_header *) page;

	/*

	 * We keep the struct sclp_buffer structure at the end

	 * of the sccb page.
@@ -57,24 +57,16 @@ sclp_make_buffer(void *page, unsigned short columns, unsigned short htab) 
	buffer = ((struct sclp_buffer *) ((addr_t) sccb + PAGE_SIZE)) - 1;

	buffer->sccb = sccb;

	buffer->retry_count = 0;

	buffer->mto_number = 0;

	buffer->mto_char_sum = 0;

	buffer->messages = 0;

	buffer->char_sum = 0;

	buffer->current_line = NULL;

	buffer->current_length = 0;

	buffer->columns = columns;

	buffer->htab = htab;



	/* initialize sccb */

	memset(sccb, 0, sizeof(struct write_sccb));

	sccb->header.length = sizeof(struct write_sccb);

	sccb->msg_buf.header.length = sizeof(struct msg_buf);

	sccb->msg_buf.header.type = EVTYP_MSG;

	sccb->msg_buf.mdb.header.length = sizeof(struct mdb);

	sccb->msg_buf.mdb.header.type = 1;

	sccb->msg_buf.mdb.header.tag = 0xD4C4C240;	/* ebcdic "MDB " */

	sccb->msg_buf.mdb.header.revision_code = 1;

	sccb->msg_buf.mdb.go.length = sizeof(struct go);

	sccb->msg_buf.mdb.go.type = 1;

	memset(sccb, 0, sizeof(struct sccb_header));

	sccb->length = sizeof(struct sccb_header);



	return buffer;

}
@@ -90,37 +82,49 @@ sclp_unmake_buffer(struct sclp_buffer *buffer) 
}



/*

 * Initialize a new Message Text Object (MTO) at the end of the provided buffer

 * with enough room for max_len characters. Return 0 on success.

 * Initialize a new message the end of the provided buffer with

 * enough room for max_len characters. Return 0 on success.

 */

static int

sclp_initialize_mto(struct sclp_buffer *buffer, int max_len)

{

	struct write_sccb *sccb;

	struct sccb_header *sccb;

	struct msg_buf *msg;

	struct mdb *mdb;

	struct go *go;

	struct mto *mto;

	int mto_size;

	int msg_size;



	/* max size of new Message Text Object including message text  */

	mto_size = sizeof(struct mto) + max_len;

	/* max size of new message including message text  */

	msg_size = sizeof(struct msg_buf) + max_len;



	/* check if current buffer sccb can contain the mto */

	sccb = buffer->sccb;

	if ((MAX_SCCB_ROOM - sccb->header.length) < mto_size)

	if ((MAX_SCCB_ROOM - sccb->length) < msg_size)

		return -ENOMEM;



	/* find address of new message text object */

	mto = (struct mto *)(((addr_t) sccb) + sccb->header.length);

	msg = (struct msg_buf *)((addr_t) sccb + sccb->length);

	memset(msg, 0, sizeof(struct msg_buf));

	msg->header.length = sizeof(struct msg_buf);

	msg->header.type = EVTYP_MSG;



	/*

	 * fill the new Message-Text Object,

	 * starting behind the former last byte of the SCCB

	 */

	memset(mto, 0, sizeof(struct mto));

	mdb = &msg->mdb;

	mdb->header.length = sizeof(struct mdb);

	mdb->header.type = 1;

	mdb->header.tag = 0xD4C4C240;	/* ebcdic "MDB " */

	mdb->header.revision_code = 1;



	go = &mdb->go;

	go->length = sizeof(struct go);

	go->type = 1;



	mto = &mdb->mto;

	mto->length = sizeof(struct mto);

	mto->type = 4;	/* message text object */

	mto->line_type_flags = LNTPFLGS_ENDTEXT; /* end text */



	/* set pointer to first byte after struct mto. */

	buffer->current_msg = msg;

	buffer->current_line = (char *) (mto + 1);

	buffer->current_length = 0;
@@ -128,45 +132,37 @@ sclp_initialize_mto(struct sclp_buffer *buffer, int max_len) 
}



/*

 * Finalize MTO initialized by sclp_initialize_mto(), updating the sizes of

 * MTO, enclosing MDB, event buffer and SCCB.

 * Finalize message initialized by sclp_initialize_mto(),

 * updating the sizes of MTO, enclosing MDB, event buffer and SCCB.

 */

static void

sclp_finalize_mto(struct sclp_buffer *buffer)

{

	struct write_sccb *sccb;

	struct mto *mto;

	int str_len, mto_size;



	str_len = buffer->current_length;

	buffer->current_line = NULL;

	buffer->current_length = 0;



	/* real size of new Message Text Object including message text	*/

	mto_size = sizeof(struct mto) + str_len;



	/* find address of new message text object */

	sccb = buffer->sccb;

	mto = (struct mto *)(((addr_t) sccb) + sccb->header.length);



	/* set size of message text object */

	mto->length = mto_size;

	struct sccb_header *sccb;

	struct msg_buf *msg;



	/*

	 * update values of sizes

	 * (SCCB, Event(Message) Buffer, Message Data Block)

	 */

	sccb->header.length += mto_size;

	sccb->msg_buf.header.length += mto_size;

	sccb->msg_buf.mdb.header.length += mto_size;

	sccb = buffer->sccb;

	msg = buffer->current_msg;

	msg->header.length += buffer->current_length;

	msg->mdb.header.length += buffer->current_length;

	msg->mdb.mto.length += buffer->current_length;

	sccb->length += msg->header.length;



	/*

	 * count number of buffered messages (= number of Message Text

	 * Objects) and number of buffered characters

	 * for the SCCB currently used for buffering and at all

	 */

	buffer->mto_number++;

	buffer->mto_char_sum += str_len;

	buffer->messages++;

	buffer->char_sum += buffer->current_length;



	buffer->current_line = NULL;

	buffer->current_length = 0;

	buffer->current_msg = NULL;

}



/*
@@ -218,7 +214,13 @@ sclp_write(struct sclp_buffer *buffer, const unsigned char *msg, int count) 
			break;

		case '\a':	/* bell, one for several times	*/

			/* set SCLP sound alarm bit in General Object */

			buffer->sccb->msg_buf.mdb.go.general_msg_flags |=

			if (buffer->current_line == NULL) {

				rc = sclp_initialize_mto(buffer,

							 buffer->columns);

				if (rc)

					return i_msg;

			}

			buffer->current_msg->mdb.go.general_msg_flags |=

				GNRLMSGFLGS_SNDALRM;

			break;

		case '\t':	/* horizontal tabulator	 */
@@ -309,11 +311,13 @@ sclp_write(struct sclp_buffer *buffer, const unsigned char *msg, int count) 
int

sclp_buffer_space(struct sclp_buffer *buffer)

{

	struct sccb_header *sccb;

	int count;



	count = MAX_SCCB_ROOM - buffer->sccb->header.length;

	sccb = buffer->sccb;

	count = MAX_SCCB_ROOM - sccb->length;

	if (buffer->current_line != NULL)

		count -= sizeof(struct mto) + buffer->current_length;

		count -= sizeof(struct msg_buf) + buffer->current_length;

	return count;

}
@@ -325,7 +329,7 @@ sclp_chars_in_buffer(struct sclp_buffer *buffer) 
{

	int count;



	count = buffer->mto_char_sum;

	count = buffer->char_sum;

	if (buffer->current_line != NULL)

		count += buffer->current_length;

	return count;
@@ -378,7 +382,7 @@ sclp_writedata_callback(struct sclp_req *request, void *data) 
{

	int rc;

	struct sclp_buffer *buffer;

	struct write_sccb *sccb;

	struct sccb_header *sccb;



	buffer = (struct sclp_buffer *) data;

	sccb = buffer->sccb;
@@ -389,7 +393,7 @@ sclp_writedata_callback(struct sclp_req *request, void *data) 
		return;

	}

	/* check SCLP response code and choose suitable action	*/

	switch (sccb->header.response_code) {

	switch (sccb->response_code) {

	case 0x0020 :

		/* Normal completion, buffer processed, message(s) sent */

		rc = 0;
@@ -403,7 +407,7 @@ sclp_writedata_callback(struct sclp_req *request, void *data) 
		/* remove processed buffers and requeue rest */

		if (sclp_remove_processed((struct sccb_header *) sccb) > 0) {

			/* not all buffers were processed */

			sccb->header.response_code = 0x0000;

			sccb->response_code = 0x0000;

			buffer->request.status = SCLP_REQ_FILLED;

			rc = sclp_add_request(request);

			if (rc == 0)
@@ -419,14 +423,14 @@ sclp_writedata_callback(struct sclp_req *request, void *data) 
			break;

		}

		/* retry request */

		sccb->header.response_code = 0x0000;

		sccb->response_code = 0x0000;

		buffer->request.status = SCLP_REQ_FILLED;

		rc = sclp_add_request(request);

		if (rc == 0)

			return;

		break;

	default:

		if (sccb->header.response_code == 0x71f0)

		if (sccb->response_code == 0x71f0)

			rc = -ENOMEM;

		else

			rc = -EINVAL;
@@ -445,25 +449,19 @@ int 
sclp_emit_buffer(struct sclp_buffer *buffer,

		 void (*callback)(struct sclp_buffer *, int))

{

	struct write_sccb *sccb;



	/* add current line if there is one */

	if (buffer->current_line != NULL)

		sclp_finalize_mto(buffer);



	/* Are there messages in the output buffer ? */

	if (buffer->mto_number == 0)

	if (buffer->messages == 0)

		return -EIO;



	sccb = buffer->sccb;

	/* Use normal write message */

	sccb->msg_buf.header.type = EVTYP_MSG;



	buffer->request.command = SCLP_CMDW_WRITE_EVENT_DATA;

	buffer->request.status = SCLP_REQ_FILLED;

	buffer->request.callback = sclp_writedata_callback;

	buffer->request.callback_data = buffer;

	buffer->request.sccb = sccb;

	buffer->request.sccb = buffer->sccb;

	buffer->callback = callback;

	return sclp_add_request(&buffer->request);

}

drivers/s390/char/sclp_rw.h

+7 −10
Original line number Diff line number Diff line
@@ -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);

};

drivers/s390/char/sclp_tty.c

+4 −4
Original line number Diff line number Diff line
@@ -84,8 +84,8 @@ sclp_tty_close(struct tty_struct *tty, struct file *filp) 
 * to change as output buffers get emptied, or if the output flow

 * control is acted. This is not an exact number because not every

 * character needs the same space in the sccb. The worst case is

 * a string of newlines. Every newlines creates a new mto which

 * needs 8 bytes.

 * a string of newlines. Every newline creates a new message which

 * needs 82 bytes.

 */

static int

sclp_tty_write_room (struct tty_struct *tty)
@@ -97,9 +97,9 @@ sclp_tty_write_room (struct tty_struct *tty) 
	spin_lock_irqsave(&sclp_tty_lock, flags);

	count = 0;

	if (sclp_ttybuf != NULL)

		count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto);

		count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct msg_buf);

	list_for_each(l, &sclp_tty_pages)

		count += NR_EMPTY_MTO_PER_SCCB;

		count += NR_EMPTY_MSG_PER_SCCB;

	spin_unlock_irqrestore(&sclp_tty_lock, flags);

	return count;

}

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