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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>
This commit is contained in:
Martin Schwidefsky 2015-10-01 14:11:35 +02:00
parent 83abeffbd5
commit 18d1a7f675
3 changed files with 78 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

136
drivers/s390/char/sclp_rw.c
View File

@ -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);
}

17
drivers/s390/char/sclp_rw.h
View File

@ -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);
};

8
drivers/s390/char/sclp_tty.c
View File

@ -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;
}