[PATCH] s390 (17/19): vt220 console.
From: Martin Schwidefsky
Date: Thu Sep 25 2003 - 12:37:50 EST
Add support for vt220 console over sclp.
diffstat:
arch/s390/defconfig | 1
drivers/s390/Kconfig | 13
drivers/s390/char/Makefile | 1
drivers/s390/char/sclp.h | 2
drivers/s390/char/sclp_cpi.c | 5
drivers/s390/char/sclp_tty.c | 2
drivers/s390/char/sclp_vt220.c | 817 +++++++++++++++++++++++++++++++++++++++++
7 files changed, 838 insertions(+), 3 deletions(-)
diff -urN linux-2.6/arch/s390/defconfig linux-2.6-s390/arch/s390/defconfig
--- linux-2.6/arch/s390/defconfig Thu Sep 25 18:33:28 2003
+++ linux-2.6-s390/arch/s390/defconfig Thu Sep 25 18:33:33 2003
@@ -137,6 +137,7 @@
CONFIG_SCLP=y
CONFIG_SCLP_TTY=y
CONFIG_SCLP_CONSOLE=y
+# CONFIG_SCLP_VT220_TTY is not set
CONFIG_SCLP_CPI=m
CONFIG_S390_TAPE=m
diff -urN linux-2.6/drivers/s390/Kconfig linux-2.6-s390/drivers/s390/Kconfig
--- linux-2.6/drivers/s390/Kconfig Thu Sep 25 18:33:28 2003
+++ linux-2.6-s390/drivers/s390/Kconfig Thu Sep 25 18:33:33 2003
@@ -101,6 +101,19 @@
Include support for using an IBM HWC line-mode terminal as the Linux
system console.
+config SCLP_VT220_TTY
+ bool "Support for SCLP VT220-compatible terminal"
+ depends on SCLP
+ help
+ Include support for an IBM SCLP VT220-compatible terminal.
+
+config SCLP_VT220_CONSOLE
+ bool "Support for console on SCLP VT220-compatible terminal"
+ depends on SCLP_VT220_TTY
+ help
+ Include support for using an IBM SCLP VT220-compatible terminal as a
+ Linux system console.
+
config SCLP_CPI
tristate "Control-Program Identification"
depends on SCLP
diff -urN linux-2.6/drivers/s390/char/Makefile linux-2.6-s390/drivers/s390/char/Makefile
--- linux-2.6/drivers/s390/char/Makefile Mon Sep 8 21:50:03 2003
+++ linux-2.6-s390/drivers/s390/char/Makefile Thu Sep 25 18:33:33 2003
@@ -11,6 +11,7 @@
obj-$(CONFIG_SCLP) += sclp.o sclp_rw.o
obj-$(CONFIG_SCLP_TTY) += sclp_tty.o
obj-$(CONFIG_SCLP_CONSOLE) += sclp_con.o
+obj-$(CONFIG_SCLP_VT220_TTY) += sclp_vt220.o
obj-$(CONFIG_SCLP_CPI) += sclp_cpi.o
obj-$(CONFIG_TN3270) += tub3270.o
tape-$(CONFIG_S390_TAPE_BLOCK) += tape_block.o
diff -urN linux-2.6/drivers/s390/char/sclp.h linux-2.6-s390/drivers/s390/char/sclp.h
--- linux-2.6/drivers/s390/char/sclp.h Mon Sep 8 21:49:54 2003
+++ linux-2.6-s390/drivers/s390/char/sclp.h Thu Sep 25 18:33:33 2003
@@ -26,6 +26,7 @@
#define EvTyp_CntlProgOpCmd 0x20
#define EvTyp_CntlProgIdent 0x0B
#define EvTyp_SigQuiesce 0x1D
+#define EvTyp_VT220Msg 0x1A
#define EvTyp_OpCmd_Mask 0x80000000
#define EvTyp_Msg_Mask 0x40000000
@@ -34,6 +35,7 @@
#define EvTyp_CtlProgOpCmd_Mask 0x00000001
#define EvTyp_CtlProgIdent_Mask 0x00200000
#define EvTyp_SigQuiesce_Mask 0x00000008
+#define EvTyp_VT220Msg_Mask 0x00000040
#define GnrlMsgFlgs_DOM 0x8000
#define GnrlMsgFlgs_SndAlrm 0x4000
diff -urN linux-2.6/drivers/s390/char/sclp_cpi.c linux-2.6-s390/drivers/s390/char/sclp_cpi.c
--- linux-2.6/drivers/s390/char/sclp_cpi.c Mon Sep 8 21:50:06 2003
+++ linux-2.6-s390/drivers/s390/char/sclp_cpi.c Thu Sep 25 18:33:33 2003
@@ -9,6 +9,7 @@
#include <linux/version.h>
#include <linux/kmod.h>
#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/string.h>
@@ -58,12 +59,12 @@
"or zSeries hardware");
static char *system_name = NULL;
-MODULE_PARM(system_name, "s");
+module_param(system_name, charp, 0);
MODULE_PARM_DESC(system_name, "e.g. hostname - max. 8 characters");
static char *sysplex_name = NULL;
#ifdef ALLOW_SYSPLEX_NAME
-MODULE_PARM(sysplex_name, "s");
+module_param(sysplex_name, charp, 0);
MODULE_PARM_DESC(sysplex_name, "if applicable - max. 8 characters");
#endif
diff -urN linux-2.6/drivers/s390/char/sclp_tty.c linux-2.6-s390/drivers/s390/char/sclp_tty.c
--- linux-2.6/drivers/s390/char/sclp_tty.c Mon Sep 8 21:49:53 2003
+++ linux-2.6-s390/drivers/s390/char/sclp_tty.c Thu Sep 25 18:33:33 2003
@@ -779,7 +779,7 @@
driver->owner = THIS_MODULE;
driver->driver_name = "sclp_line";
- driver->name = "ttyS";
+ driver->name = "sclp_line";
driver->major = TTY_MAJOR;
driver->minor_start = 64;
driver->type = TTY_DRIVER_TYPE_SYSTEM;
diff -urN linux-2.6/drivers/s390/char/sclp_vt220.c linux-2.6-s390/drivers/s390/char/sclp_vt220.c
--- linux-2.6/drivers/s390/char/sclp_vt220.c Thu Jan 1 01:00:00 1970
+++ linux-2.6-s390/drivers/s390/char/sclp_vt220.c Thu Sep 25 18:33:33 2003
@@ -0,0 +1,817 @@
+/*
+ * drivers/s390/char/sclp_vt220.c
+ * SCLP VT220 terminal driver.
+ *
+ * S390 version
+ * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Peter Oberparleiter <Peter.Oberparleiter@xxxxxxxxxx>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/major.h>
+#include <linux/console.h>
+#include <linux/kdev_t.h>
+#include <linux/bootmem.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include "sclp.h"
+
+#define SCLP_VT220_PRINT_HEADER "sclp vt220 tty driver: "
+#define SCLP_VT220_MAJOR TTY_MAJOR
+#define SCLP_VT220_MINOR 65
+#define SCLP_VT220_DRIVER_NAME "sclp_vt220"
+#define SCLP_VT220_DEVICE_NAME "sclp_vt"
+#define SCLP_VT220_CONSOLE_NAME "ttyS"
+#define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */
+
+/* Representation of a single write request */
+struct sclp_vt220_request {
+ struct list_head list;
+ struct sclp_req sclp_req;
+ int retry_count;
+ struct timer_list retry_timer;
+};
+
+/* VT220 SCCB */
+struct sclp_vt220_sccb {
+ struct sccb_header header;
+ struct evbuf_header evbuf;
+};
+
+#define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \
+ sizeof(struct sclp_vt220_request) - \
+ sizeof(struct sclp_vt220_sccb))
+
+/* Structures and data needed to register tty driver */
+static struct tty_driver *sclp_vt220_driver;
+
+/* The tty_struct that the kernel associated with us */
+static struct tty_struct *sclp_vt220_tty;
+
+/* Lock to protect internal data from concurrent access */
+static spinlock_t sclp_vt220_lock;
+
+/* List of empty pages to be used as write request buffers */
+static struct list_head sclp_vt220_empty;
+
+/* List of pending requests */
+static struct list_head sclp_vt220_outqueue;
+
+/* Number of requests in outqueue */
+static int sclp_vt220_outqueue_count;
+
+/* Wait queue used to delay write requests while we've run out of buffers */
+static wait_queue_head_t sclp_vt220_waitq;
+
+/* Timer used for delaying write requests to merge subsequent messages into
+ * a single buffer */
+static struct timer_list sclp_vt220_timer;
+
+/* Pointer to current request buffer which has been partially filled but not
+ * yet sent */
+static struct sclp_vt220_request *sclp_vt220_current_request;
+
+/* Number of characters in current request buffer */
+static int sclp_vt220_buffered_chars;
+
+/* Flag indicating whether this driver has already been initialized */
+static int sclp_vt220_initialized = 0;
+
+/* Flag indicating that sclp_vt220_current_request should really
+ * have been already queued but wasn't because the SCLP was processing
+ * another buffer */
+static int sclp_vt220_flush_later;
+
+static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf);
+static void __sclp_vt220_emit(struct sclp_vt220_request *request);
+static void sclp_vt220_emit_current(void);
+
+/* Registration structure for our interest in SCLP event buffers */
+static struct sclp_register sclp_vt220_register = {
+ .send_mask = EvTyp_VT220Msg_Mask,
+ .receive_mask = EvTyp_VT220Msg_Mask,
+ .state_change_fn = NULL,
+ .receiver_fn = sclp_vt220_receiver_fn
+};
+
+
+/*
+ * Put provided request buffer back into queue and check emit pending
+ * buffers if necessary.
+ */
+static void
+sclp_vt220_process_queue(struct sclp_vt220_request *request)
+{
+ unsigned long flags;
+ struct sclp_vt220_request *next;
+ void *page;
+
+ /* Put buffer back to list of empty buffers */
+ page = request->sclp_req.sccb;
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ /* Move request from outqueue to empty queue */
+ list_del(&request->list);
+ sclp_vt220_outqueue_count--;
+ list_add_tail((struct list_head *) page, &sclp_vt220_empty);
+ /* Check if there is a pending buffer on the out queue. */
+ next = NULL;
+ if (!list_empty(&sclp_vt220_outqueue))
+ next = list_entry(sclp_vt220_outqueue.next,
+ struct sclp_vt220_request, list);
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ if (next != NULL)
+ __sclp_vt220_emit(next);
+ else if (sclp_vt220_flush_later)
+ sclp_vt220_emit_current();
+ wake_up(&sclp_vt220_waitq);
+ /* Check if the tty needs a wake up call */
+ if (sclp_vt220_tty != NULL) {
+ if ((sclp_vt220_tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
+ (sclp_vt220_tty->ldisc.write_wakeup != NULL))
+ (sclp_vt220_tty->ldisc.write_wakeup)(sclp_vt220_tty);
+ wake_up_interruptible(&sclp_vt220_tty->write_wait);
+ }
+}
+
+/*
+ * Retry sclp write request after waiting some time for an sclp equipment
+ * check to pass.
+ */
+static void
+sclp_vt220_retry(unsigned long data)
+{
+ struct sclp_vt220_request *request;
+ struct sclp_vt220_sccb *sccb;
+
+ request = (struct sclp_vt220_request *) data;
+ request->sclp_req.status = SCLP_REQ_FILLED;
+ sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+ sccb->header.response_code = 0x0000;
+ sclp_add_request(&request->sclp_req);
+}
+
+#define SCLP_BUFFER_MAX_RETRY 5
+#define SCLP_BUFFER_RETRY_INTERVAL 2
+
+/*
+ * Callback through which the result of a write request is reported by the
+ * SCLP.
+ */
+static void
+sclp_vt220_callback(struct sclp_req *request, void *data)
+{
+ struct sclp_vt220_request *vt220_request;
+ struct sclp_vt220_sccb *sccb;
+
+ vt220_request = (struct sclp_vt220_request *) data;
+ if (request->status == SCLP_REQ_FAILED) {
+ sclp_vt220_process_queue(vt220_request);
+ return;
+ }
+ sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb;
+
+ /* Check SCLP response code and choose suitable action */
+ switch (sccb->header.response_code) {
+ case 0x0020 :
+ break;
+
+ case 0x05f0: /* Target resource in improper state */
+ break;
+
+ case 0x0340: /* Contained SCLP equipment check */
+ if (vt220_request->retry_count++ > SCLP_BUFFER_MAX_RETRY)
+ break;
+ /* 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;
+ vt220_request->sclp_req.status = SCLP_REQ_FILLED;
+ sclp_add_request(request);
+ return;
+ }
+ break;
+
+ case 0x0040: /* SCLP equipment check */
+ if (vt220_request->retry_count++ > SCLP_BUFFER_MAX_RETRY)
+ break;
+ /* Wait some time, then retry request */
+ vt220_request->retry_timer.function = sclp_vt220_retry;
+ vt220_request->retry_timer.data =
+ (unsigned long) vt220_request;
+ vt220_request->retry_timer.expires =
+ jiffies + SCLP_BUFFER_RETRY_INTERVAL*HZ;
+ add_timer(&vt220_request->retry_timer);
+ return;
+
+ default:
+ break;
+ }
+ sclp_vt220_process_queue(vt220_request);
+}
+
+/*
+ * Emit vt220 request buffer to SCLP.
+ */
+static void
+__sclp_vt220_emit(struct sclp_vt220_request *request)
+{
+ if (!(sclp_vt220_register.sclp_send_mask & EvTyp_VT220Msg_Mask)) {
+ request->sclp_req.status = SCLP_REQ_FAILED;
+ sclp_vt220_callback(&request->sclp_req, (void *) request);
+ return;
+ }
+ request->sclp_req.command = SCLP_CMDW_WRITEDATA;
+ request->sclp_req.status = SCLP_REQ_FILLED;
+ request->sclp_req.callback = sclp_vt220_callback;
+ request->sclp_req.callback_data = (void *) request;
+
+ sclp_add_request(&request->sclp_req);
+}
+
+/*
+ * Queue and emit given request.
+ */
+static void
+sclp_vt220_emit(struct sclp_vt220_request *request)
+{
+ unsigned long flags;
+ int count;
+
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ list_add_tail(&request->list, &sclp_vt220_outqueue);
+ count = sclp_vt220_outqueue_count++;
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ /* Emit only the first buffer immediately - callback takes care of
+ * the rest */
+ if (count == 0)
+ __sclp_vt220_emit(request);
+}
+
+/*
+ * Queue and emit current request.
+ */
+static void
+sclp_vt220_emit_current(void)
+{
+ unsigned long flags;
+ struct sclp_vt220_request *request;
+ struct sclp_vt220_sccb *sccb;
+
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ request = NULL;
+ if (sclp_vt220_current_request != NULL) {
+ sccb = (struct sclp_vt220_sccb *)
+ sclp_vt220_current_request->sclp_req.sccb;
+ /* Only emit buffers with content */
+ if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) {
+ request = sclp_vt220_current_request;
+ sclp_vt220_current_request = NULL;
+ if (timer_pending(&sclp_vt220_timer))
+ del_timer(&sclp_vt220_timer);
+ }
+ sclp_vt220_flush_later = 0;
+ }
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ if (request != NULL)
+ sclp_vt220_emit(request);
+}
+
+#define SCLP_NORMAL_WRITE 0x00
+
+/*
+ * Helper function to initialize a page with the sclp request structure.
+ */
+static struct sclp_vt220_request *
+sclp_vt220_initialize_page(void *page)
+{
+ struct sclp_vt220_request *request;
+ struct sclp_vt220_sccb *sccb;
+
+ /* Place request structure at end of page */
+ request = ((struct sclp_vt220_request *)
+ ((addr_t) page + PAGE_SIZE)) - 1;
+ init_timer(&request->retry_timer);
+ request->retry_count = 0;
+ request->sclp_req.sccb = page;
+ /* SCCB goes at start of page */
+ sccb = (struct sclp_vt220_sccb *) page;
+ memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb));
+ sccb->header.length = sizeof(struct sclp_vt220_sccb);
+ sccb->header.function_code = SCLP_NORMAL_WRITE;
+ sccb->header.response_code = 0x0000;
+ sccb->evbuf.type = EvTyp_VT220Msg;
+ sccb->evbuf.length = sizeof(struct evbuf_header);
+
+ return request;
+}
+
+static inline unsigned int
+sclp_vt220_space_left(struct sclp_vt220_request *request)
+{
+ struct sclp_vt220_sccb *sccb;
+ sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+ return PAGE_SIZE - sizeof(struct sclp_vt220_request) -
+ sccb->header.length;
+}
+
+static inline unsigned int
+sclp_vt220_chars_stored(struct sclp_vt220_request *request)
+{
+ struct sclp_vt220_sccb *sccb;
+ sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+ return sccb->evbuf.length - sizeof(struct evbuf_header);
+}
+
+/*
+ * Add msg to buffer associated with request. Return the number of characters
+ * added or -EFAULT on error.
+ */
+static int
+sclp_vt220_add_msg(struct sclp_vt220_request *request,
+ const unsigned char *msg, int count, int from_user,
+ int convertlf)
+{
+ struct sclp_vt220_sccb *sccb;
+ void *buffer;
+ unsigned char c;
+ int from;
+ int to;
+
+ if (count > sclp_vt220_space_left(request))
+ count = sclp_vt220_space_left(request);
+ if (count <= 0)
+ return 0;
+
+ sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
+ buffer = (void *) ((addr_t) sccb + sccb->header.length);
+
+ if (convertlf) {
+ /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/
+ for (from=0, to=0;
+ (from < count) && (to < sclp_vt220_space_left(request));
+ from++) {
+ /* Retrieve character */
+ if (from_user) {
+ if (get_user(c, msg + from) != 0)
+ return -EFAULT;
+ } else
+ c = msg[from];
+ /* Perform conversion */
+ if (c == 0x0a) {
+ if (to + 1 < sclp_vt220_space_left(request)) {
+ ((unsigned char *) buffer)[to++] = c;
+ ((unsigned char *) buffer)[to++] = 0x0d;
+ } else
+ break;
+
+ } else
+ ((unsigned char *) buffer)[to++] = c;
+ }
+ sccb->header.length += to;
+ sccb->evbuf.length += to;
+ return from;
+ } else {
+ if (from_user) {
+ if (copy_from_user(buffer, (void *) msg, count) != 0)
+ return -EFAULT;
+ }
+ else
+ memcpy(buffer, (const void *) msg, count);
+ sccb->header.length += count;
+ sccb->evbuf.length += count;
+ return count;
+ }
+}
+
+/*
+ * Emit buffer after having waited long enough for more data to arrive.
+ */
+static void
+sclp_vt220_timeout(unsigned long data)
+{
+ sclp_vt220_emit_current();
+}
+
+#define BUFFER_MAX_DELAY HZ/2
+
+/*
+ * Internal implementation of the write function. Write COUNT bytes of data
+ * from memory at BUF which may reside in user space (specified by FROM_USER)
+ * to the SCLP interface. In case that the data does not fit into the current
+ * write buffer, emit the current one and allocate a new one. If there are no
+ * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
+ * is non-zero, the buffer will be scheduled for emitting after a timeout -
+ * otherwise the user has to explicitly call the flush function.
+ * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message
+ * buffer should be converted to 0x0a 0x0d. After completion, return the number
+ * of bytes written.
+ */
+static int
+__sclp_vt220_write(int from_user, const unsigned char *buf, int count,
+ int do_schedule, int convertlf)
+{
+ unsigned long flags;
+ void *page;
+ int written;
+ int overall_written;
+
+ if (count <= 0)
+ return 0;
+ overall_written = 0;
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ do {
+ /* Create a sclp output buffer if none exists yet */
+ if (sclp_vt220_current_request == NULL) {
+ while (list_empty(&sclp_vt220_empty)) {
+ spin_unlock_irqrestore(&sclp_vt220_lock,
+ flags);
+ if (in_interrupt())
+ sclp_sync_wait();
+ else
+ wait_event(sclp_vt220_waitq,
+ !list_empty(&sclp_vt220_empty));
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ }
+ page = (void *) sclp_vt220_empty.next;
+ list_del((struct list_head *) page);
+ sclp_vt220_current_request =
+ sclp_vt220_initialize_page(page);
+ }
+ /* Try to write the string to the current request buffer */
+ written = sclp_vt220_add_msg(sclp_vt220_current_request,
+ buf, count, from_user, convertlf);
+ if (written > 0)
+ overall_written += written;
+ if (written == -EFAULT || written == count)
+ break;
+ /*
+ * Not all characters could be written to the current
+ * output buffer. Emit the buffer, create a new buffer
+ * and then output the rest of the string.
+ */
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ sclp_vt220_emit_current();
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ buf += written;
+ count -= written;
+ } while (count > 0);
+ /* Setup timer to output current console buffer after some time */
+ if (sclp_vt220_current_request != NULL &&
+ !timer_pending(&sclp_vt220_timer) && do_schedule) {
+ sclp_vt220_timer.function = sclp_vt220_timeout;
+ sclp_vt220_timer.data = 0UL;
+ sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY;
+ add_timer(&sclp_vt220_timer);
+ }
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ return overall_written;
+}
+
+/*
+ * This routine is called by the kernel to write a series of
+ * characters to the tty device. The characters may come from
+ * user space or kernel space. This routine will return the
+ * number of characters actually accepted for writing.
+ */
+static int
+sclp_vt220_write(struct tty_struct *tty, int from_user,
+ const unsigned char *buf, int count)
+{
+ return __sclp_vt220_write(from_user, buf, count, 1, 0);
+}
+
+#define SCLP_VT220_SESSION_ENDED 0x01
+#define SCLP_VT220_SESSION_STARTED 0x80
+#define SCLP_VT220_SESSION_DATA 0x00
+
+/*
+ * Called by the SCLP to report incoming event buffers.
+ */
+static void
+sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
+{
+ char *buffer;
+ unsigned int count;
+
+ /* Ignore input if device is not open */
+ if (sclp_vt220_tty == NULL)
+ return;
+
+ buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header));
+ count = evbuf->length - sizeof(struct evbuf_header);
+
+ switch (*buffer) {
+ case SCLP_VT220_SESSION_ENDED:
+ case SCLP_VT220_SESSION_STARTED:
+ break;
+ case SCLP_VT220_SESSION_DATA:
+ /* Send input to line discipline */
+ buffer++;
+ count--;
+ /* Prevent buffer overrun by discarding input. Note that
+ * because buffer_push works asynchronously, we cannot wait
+ * for the buffer to be emptied. */
+ if (count + sclp_vt220_tty->flip.count > TTY_FLIPBUF_SIZE)
+ count = TTY_FLIPBUF_SIZE - sclp_vt220_tty->flip.count;
+ memcpy(sclp_vt220_tty->flip.char_buf_ptr, buffer, count);
+ memset(sclp_vt220_tty->flip.flag_buf_ptr, TTY_NORMAL, count);
+ sclp_vt220_tty->flip.char_buf_ptr += count;
+ sclp_vt220_tty->flip.flag_buf_ptr += count;
+ sclp_vt220_tty->flip.count += count;
+ tty_flip_buffer_push(sclp_vt220_tty);
+ break;
+ }
+}
+
+/*
+ * This routine is called when a particular tty device is opened.
+ */
+static int
+sclp_vt220_open(struct tty_struct *tty, struct file *filp)
+{
+ sclp_vt220_tty = tty;
+ tty->driver_data = NULL;
+ tty->low_latency = 0;
+ return 0;
+}
+
+/*
+ * This routine is called when a particular tty device is closed.
+ */
+static void
+sclp_vt220_close(struct tty_struct *tty, struct file *filp)
+{
+ if (tty->count > 1)
+ return;
+ sclp_vt220_tty = NULL;
+}
+
+/*
+ * This routine is called by the kernel to write a single
+ * character to the tty device. If the kernel uses this routine,
+ * it must call the flush_chars() routine (if defined) when it is
+ * done stuffing characters into the driver.
+ *
+ * NOTE: include/linux/tty_driver.h specifies that a character should be
+ * ignored if there is no room in the queue. This driver implements a different
+ * semantic in that it will block when there is no more room left.
+ */
+static void
+sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
+{
+ __sclp_vt220_write(0, &ch, 1, 0, 0);
+}
+
+/*
+ * This routine is called by the kernel after it has written a
+ * series of characters to the tty device using put_char().
+ */
+static void
+sclp_vt220_flush_chars(struct tty_struct *tty)
+{
+ if (sclp_vt220_outqueue_count == 0)
+ sclp_vt220_emit_current();
+ else
+ sclp_vt220_flush_later = 1;
+}
+
+/*
+ * This routine returns the numbers of characters the tty driver
+ * will accept for queuing to be written. This number is subject
+ * to change as output buffers get emptied, or if the output flow
+ * control is acted.
+ */
+static int
+sclp_vt220_write_room(struct tty_struct *tty)
+{
+ unsigned long flags;
+ struct list_head *l;
+ int count;
+
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ count = 0;
+ if (sclp_vt220_current_request != NULL)
+ count = sclp_vt220_space_left(sclp_vt220_current_request);
+ list_for_each(l, &sclp_vt220_empty)
+ count += SCLP_VT220_MAX_CHARS_PER_BUFFER;
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ return count;
+}
+
+/*
+ * Return number of buffered chars.
+ */
+static int
+sclp_vt220_chars_in_buffer(struct tty_struct *tty)
+{
+ unsigned long flags;
+ struct list_head *l;
+ struct sclp_vt220_request *r;
+ int count;
+
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ count = 0;
+ if (sclp_vt220_current_request != NULL)
+ count = sclp_vt220_chars_stored(sclp_vt220_current_request);
+ list_for_each(l, &sclp_vt220_outqueue) {
+ r = list_entry(l, struct sclp_vt220_request, list);
+ count += sclp_vt220_chars_stored(r);
+ }
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ return count;
+}
+
+static void
+__sclp_vt220_flush_buffer(void)
+{
+ unsigned long flags;
+
+ sclp_vt220_emit_current();
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ if (timer_pending(&sclp_vt220_timer))
+ del_timer(&sclp_vt220_timer);
+ while (sclp_vt220_outqueue_count > 0) {
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+ sclp_sync_wait();
+ spin_lock_irqsave(&sclp_vt220_lock, flags);
+ }
+ spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+}
+
+/*
+ * Pass on all buffers to the hardware. Return only when there are no more
+ * buffers pending.
+ */
+static void
+sclp_vt220_flush_buffer(struct tty_struct *tty)
+{
+ sclp_vt220_emit_current();
+}
+
+/*
+ * Initialize all relevant components and register driver with system.
+ */
+static int
+__sclp_vt220_init(int early)
+{
+ void *page;
+ int i;
+
+ if (sclp_vt220_initialized)
+ return 0;
+ sclp_vt220_initialized = 1;
+ spin_lock_init(&sclp_vt220_lock);
+ INIT_LIST_HEAD(&sclp_vt220_empty);
+ INIT_LIST_HEAD(&sclp_vt220_outqueue);
+ init_waitqueue_head(&sclp_vt220_waitq);
+ init_timer(&sclp_vt220_timer);
+ sclp_vt220_current_request = NULL;
+ sclp_vt220_buffered_chars = 0;
+ sclp_vt220_outqueue_count = 0;
+ sclp_vt220_tty = NULL;
+ sclp_vt220_flush_later = 0;
+
+ /* Allocate pages for output buffering */
+ for (i = 0; i < (early ? MAX_CONSOLE_PAGES : MAX_KMEM_PAGES); i++) {
+ if (early)
+ page = alloc_bootmem_low_pages(PAGE_SIZE);
+ else
+ page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+ if (!page)
+ return -ENOMEM;
+ list_add_tail((struct list_head *) page, &sclp_vt220_empty);
+ }
+ return 0;
+}
+
+static struct tty_operations sclp_vt220_ops = {
+ .open = sclp_vt220_open,
+ .close = sclp_vt220_close,
+ .write = sclp_vt220_write,
+ .put_char = sclp_vt220_put_char,
+ .flush_chars = sclp_vt220_flush_chars,
+ .write_room = sclp_vt220_write_room,
+ .chars_in_buffer = sclp_vt220_chars_in_buffer,
+ .flush_buffer = sclp_vt220_flush_buffer
+};
+
+/*
+ * Register driver with SCLP and Linux and initialize internal tty structures.
+ */
+int __init
+sclp_vt220_tty_init(void)
+{
+ struct tty_driver *driver;
+ int rc;
+
+ /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
+ * symmetry between VM and LPAR systems regarding ttyS1. */
+ driver = alloc_tty_driver(1);
+ if (!driver)
+ return -ENOMEM;
+ rc = __sclp_vt220_init(0);
+ if (rc) {
+ put_tty_driver(driver);
+ return rc;
+ }
+ rc = sclp_register(&sclp_vt220_register);
+ if (rc) {
+ printk(KERN_ERR SCLP_VT220_PRINT_HEADER
+ "could not register tty - "
+ "sclp_register returned %d\n", rc);
+ put_tty_driver(driver);
+ return rc;
+ }
+
+ driver->owner = THIS_MODULE;
+ driver->driver_name = SCLP_VT220_DRIVER_NAME;
+ driver->name = SCLP_VT220_DEVICE_NAME;
+ driver->major = SCLP_VT220_MAJOR;
+ driver->minor_start = SCLP_VT220_MINOR;
+ driver->type = TTY_DRIVER_TYPE_SYSTEM;
+ driver->subtype = SYSTEM_TYPE_TTY;
+ driver->init_termios = tty_std_termios;
+ driver->flags = TTY_DRIVER_REAL_RAW;
+ tty_set_operations(driver, &sclp_vt220_ops);
+
+ rc = tty_register_driver(driver);
+ if (rc) {
+ printk(KERN_ERR SCLP_VT220_PRINT_HEADER
+ "could not register tty - "
+ "tty_register_driver returned %d\n", rc);
+ put_tty_driver(driver);
+ return rc;
+ }
+ sclp_vt220_driver = driver;
+ return 0;
+}
+
+module_init(sclp_vt220_tty_init);
+
+#ifdef CONFIG_SCLP_VT220_CONSOLE
+
+static void
+sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
+{
+ __sclp_vt220_write(0, (const unsigned char *) buf, count, 1, 1);
+}
+
+static struct tty_driver *
+sclp_vt220_con_device(struct console *c, int *index)
+{
+ *index = 0;
+ return sclp_vt220_driver;
+}
+
+/*
+ * This routine is called from panic when the kernel is going to give up.
+ * We have to make sure that all buffers will be flushed to the SCLP.
+ * Note that this function may be called from within an interrupt context.
+ */
+static void
+sclp_vt220_con_unblank(void)
+{
+ __sclp_vt220_flush_buffer();
+}
+
+/* Structure needed to register with printk */
+static struct console sclp_vt220_console =
+{
+ .name = SCLP_VT220_CONSOLE_NAME,
+ .write = sclp_vt220_con_write,
+ .device = sclp_vt220_con_device,
+ .unblank = sclp_vt220_con_unblank,
+ .flags = CON_PRINTBUFFER,
+ .index = SCLP_VT220_CONSOLE_INDEX
+};
+
+static int __init
+sclp_vt220_con_init(void)
+{
+ int rc;
+
+ if (!CONSOLE_IS_SCLP)
+ return 0;
+ rc = __sclp_vt220_init(1);
+ if (rc)
+ return rc;
+ /* Attach linux console */
+ register_console(&sclp_vt220_console);
+ return 0;
+}
+
+console_initcall(sclp_vt220_con_init);
+#endif /* CONFIG_SCLP_VT220_CONSOLE */
+
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/