Patch to add SysRq handling to 3270 console

[Pete Zaitcev <zaitcev@redhat.com>]

The 3270 console is superior to 3215 in several respects:
- It shows brackets correctly
- It allows for passwords to be not echoed
- It permits full screen applications
- Its users do not need to hit Enter twice for every line

Its only deficiency was that SysRq was not implemented.
The attached patch rectifies that and allows to start
migration from 3215 for VM users.

Matin et. al., please consider.

I am going to look into tub sleeping with spinlocks soonish,
but please don't hold this patch for that problem.

Yours,
-- Pete

diff -urN -X dontdiff linux-2.5.69-bk12/arch/s390/kernel/s390_ksyms.c linux-2.5.69-bk12-s390/arch/s390/kernel/s390_ksyms.c
--- linux-2.5.69-bk12/arch/s390/kernel/s390_ksyms.c	2003-05-17 10:02:23.000000000 -0700
+++ linux-2.5.69-bk12-s390/arch/s390/kernel/s390_ksyms.c	2003-05-22 15:31:35.000000000 -0700
@@ -13,6 +13,7 @@
 #include <asm/delay.h>
 #include <asm/pgalloc.h>
 #include <asm/setup.h>
+#include <asm/ctrlchar.h>
 #ifdef CONFIG_IP_MULTICAST
 #include <net/arp.h>
 #endif
@@ -85,3 +86,5 @@
 EXPORT_SYMBOL(console_device);
 EXPORT_SYMBOL_NOVERS(do_call_softirq);
 EXPORT_SYMBOL(sys_wait4);
+EXPORT_SYMBOL(ctrlchar_init);
+EXPORT_SYMBOL(ctrlchar_handle);
diff -urN -X dontdiff linux-2.5.69-bk12/drivers/s390/char/con3215.c linux-2.5.69-bk12-s390/drivers/s390/char/con3215.c
--- linux-2.5.69-bk12/drivers/s390/char/con3215.c	2003-05-11 12:56:33.000000000 -0700
+++ linux-2.5.69-bk12-s390/drivers/s390/char/con3215.c	2003-05-22 13:57:25.000000000 -0700
@@ -32,8 +32,7 @@
 #include <asm/delay.h>
 #include <asm/cpcmd.h>
 #include <asm/setup.h>
-
-#include "ctrlchar.h"
+#include <asm/ctrlchar.h>
 
 #define NR_3215		    1
 #define NR_3215_REQ	    (4*NR_3215)
@@ -441,7 +440,7 @@
 			if (count >= TTY_FLIPBUF_SIZE - tty->flip.count)
 				count = TTY_FLIPBUF_SIZE - tty->flip.count - 1;
 			EBCASC(raw->inbuf, count);
-			cchar = ctrlchar_handle(raw->inbuf, count, tty);
+			cchar = ctrlchar_handle(raw->inbuf, count, tty, 1);
 			switch (cchar & CTRLCHAR_MASK) {
 			case CTRLCHAR_SYSRQ:
 				break;
diff -urN -X dontdiff linux-2.5.69-bk12/drivers/s390/char/ctrlchar.c linux-2.5.69-bk12-s390/drivers/s390/char/ctrlchar.c
--- linux-2.5.69-bk12/drivers/s390/char/ctrlchar.c	2003-03-24 14:01:49.000000000 -0800
+++ linux-2.5.69-bk12-s390/drivers/s390/char/ctrlchar.c	2003-05-22 13:57:25.000000000 -0700
@@ -13,7 +13,7 @@
 #include <linux/sysrq.h>
 #include <linux/ctype.h>
 
-#include "ctrlchar.h"
+#include <asm/ctrlchar.h>
 
 #ifdef CONFIG_MAGIC_SYSRQ
 static int ctrlchar_sysrq_key;
@@ -40,7 +40,8 @@
  *         with CTRLCHAR_CTRL
  */
 unsigned int
-ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty)
+ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty,
+    int is_console)
 {
 	if ((len < 2) || (len > 3))
 		return CTRLCHAR_NONE;
@@ -52,7 +53,7 @@
 
 #ifdef CONFIG_MAGIC_SYSRQ
 	/* racy */
-	if (len == 3 && buf[1] == '-') {
+	if (is_console && len == 3 && buf[1] == '-') {
 		ctrlchar_sysrq_key = buf[2];
 		ctrlchar_work.data = tty;
 		schedule_work(&ctrlchar_work);
diff -urN -X dontdiff linux-2.5.69-bk12/drivers/s390/char/ctrlchar.h linux-2.5.69-bk12-s390/drivers/s390/char/ctrlchar.h
--- linux-2.5.69-bk12/drivers/s390/char/ctrlchar.h	2003-03-24 14:01:46.000000000 -0800
+++ linux-2.5.69-bk12-s390/drivers/s390/char/ctrlchar.h	1969-12-31 16:00:00.000000000 -0800
@@ -1,20 +0,0 @@
-/*
- *  drivers/s390/char/ctrlchar.c
- *  Unified handling of special chars.
- *
- *    Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
- *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
- *
- */
-
-#include <linux/tty.h>
-
-extern unsigned int
-ctrlchar_handle(const unsigned char *buf, int len, struct tty_struct *tty);
-
-
-#define CTRLCHAR_NONE  (1 << 8)
-#define CTRLCHAR_CTRL  (2 << 8)
-#define CTRLCHAR_SYSRQ (3 << 8)
-
-#define CTRLCHAR_MASK (~0xffu)
diff -urN -X dontdiff linux-2.5.69-bk12/drivers/s390/char/sclp_tty.c linux-2.5.69-bk12-s390/drivers/s390/char/sclp_tty.c
--- linux-2.5.69-bk12/drivers/s390/char/sclp_tty.c	2003-05-11 12:56:33.000000000 -0700
+++ linux-2.5.69-bk12-s390/drivers/s390/char/sclp_tty.c	2003-05-22 13:57:45.000000000 -0700
@@ -17,8 +17,8 @@
 #include <linux/wait.h>
 #include <linux/slab.h>
 #include <asm/uaccess.h>
+#include <asm/ctrlchar.h>
 
-#include "ctrlchar.h"
 #include "sclp.h"
 #include "sclp_rw.h"
 #include "sclp_tty.h"
@@ -485,7 +485,7 @@
 	 */
 	if (sclp_tty == NULL)
 		return;
-	cchar = ctrlchar_handle(buf, count, sclp_tty);
+	cchar = ctrlchar_handle(buf, count, sclp_tty, 1);
 	switch (cchar & CTRLCHAR_MASK) {
 	case CTRLCHAR_SYSRQ:
 		break;
diff -urN -X dontdiff linux-2.5.69-bk12/drivers/s390/char/tubtty.c linux-2.5.69-bk12-s390/drivers/s390/char/tubtty.c
--- linux-2.5.69-bk12/drivers/s390/char/tubtty.c	2003-05-17 10:02:33.000000000 -0700
+++ linux-2.5.69-bk12-s390/drivers/s390/char/tubtty.c	2003-05-22 13:57:46.000000000 -0700
@@ -10,6 +10,7 @@
  *  Author:  Richard Hitt
  */
 #include <linux/config.h>
+#include <asm/ctrlchar.h>
 #include "tubio.h"
 
 /* Initialization & uninitialization for tubtty */
@@ -119,6 +120,8 @@
 	td->read_proc = tty3270_read_proc;
 	td->write_proc = tty3270_write_proc;
 
+	ctrlchar_init();
+
 	rc = tty_register_driver(td);
 	if (rc) {
 		printk(KERN_ERR "tty3270 registration failed with %d\n", rc);
@@ -865,23 +868,22 @@
 {
 	struct tty_struct *tty;
 	int func = -1;
+	int is_console = 0;
+	unsigned int cchar;
 
 	if ((tty = tubp->tty) == NULL)
 		return;
 	if (count < 0)
 		return;
-	if (count == 2 && (cp[0] == '^' || cp[0] == '\252')) {
-		switch(cp[1]) {
-		case 'c':  case 'C':
-			func = INTR_CHAR(tty);
-			break;
-		case 'd':  case 'D':
-			func = EOF_CHAR(tty);
-			break;
-		case 'z':  case 'Z':
-			func = SUSP_CHAR(tty);
-			break;
-		}
+#ifdef CONFIG_TN3270_CONSOLE
+	if (CONSOLE_IS_3270 && tub3270_con_tubp == tubp)
+		is_console = 1;
+#endif
+	cchar = ctrlchar_handle(cp, count, tty, is_console);
+	if ((cchar & CTRLCHAR_MASK) != CTRLCHAR_NONE) {
+		if ((cchar & CTRLCHAR_MASK) != CTRLCHAR_CTRL)
+			return;
+		func = cchar & 0xFF;
 	} else if (count == 2 && cp[0] == 0x1b) {        /* if ESC */
 		int inc = 0;
 		char buf[GEOM_INPLEN + 1];
diff -urN -X dontdiff linux-2.5.69-bk12/include/asm-s390/ctrlchar.h linux-2.5.69-bk12-s390/include/asm-s390/ctrlchar.h
--- linux-2.5.69-bk12/include/asm-s390/ctrlchar.h	1969-12-31 16:00:00.000000000 -0800
+++ linux-2.5.69-bk12-s390/include/asm-s390/ctrlchar.h	2003-05-22 13:57:46.000000000 -0700
@@ -0,0 +1,20 @@
+/*
+ *  Implemented in drivers/s390/char/ctrlchar.c
+ *  Unified handling of special chars.
+ *
+ *    Copyright (C) 2001 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Fritz Elfert <felfert@millenux.com> <elfert@de.ibm.com>
+ *
+ */
+
+struct tty_struct;
+
+extern unsigned int ctrlchar_handle(const unsigned char *buf, int len,
+    struct tty_struct *tty, int is_console);
+extern void ctrlchar_init(void);
+
+#define CTRLCHAR_CTRL  (0 << 8)
+#define CTRLCHAR_NONE  (1 << 8)
+#define CTRLCHAR_SYSRQ (2 << 8)
+
+#define CTRLCHAR_MASK (~0xffu)