[S390] sclp: Get rid of in_atomic() use.

Reintroduces in_interrupt() check in sclp_tty code. Add may_schedule
parameter to vt220 write function, so we can let the write function
know if it may schedule or not. So we disallow scheduling for all
console calls and may allow them for tty calls.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

drivers/s390/char/sclp_tty.c

@@ -332,7 +332,7 @@ sclp_tty_write_string(const unsigned char *str, int count)
 		if (sclp_ttybuf == NULL) {
 			while (list_empty(&sclp_tty_pages)) {
 				spin_unlock_irqrestore(&sclp_tty_lock, flags);
-				if (in_atomic())
+				if (in_interrupt())
 					sclp_sync_wait();
 				else
 					wait_event(sclp_tty_waitq,

drivers/s390/char/sclp_vt220.c

@@ -383,7 +383,7 @@ sclp_vt220_timeout(unsigned long data)
  */
 static int
 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
-		   int convertlf)
+		   int convertlf, int may_schedule)
 {
 	unsigned long flags;
 	void *page;
@@ -398,9 +398,8 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
 		/* 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_atomic())
+				spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+				if (in_interrupt() || !may_schedule)
 					sclp_sync_wait();
 				else
 					wait_event(sclp_vt220_waitq,
@@ -450,7 +449,7 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
 static int
 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
 {
-	return __sclp_vt220_write(buf, count, 1, 0);
+	return __sclp_vt220_write(buf, count, 1, 0, 1);
 }
 
 #define SCLP_VT220_SESSION_ENDED	0x01
@@ -529,7 +528,7 @@ sclp_vt220_close(struct tty_struct *tty, struct file *filp)
 static void
 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
 {
-	__sclp_vt220_write(&ch, 1, 0, 0);
+	__sclp_vt220_write(&ch, 1, 0, 0, 1);
 }
 
 /*
@@ -746,7 +745,7 @@ __initcall(sclp_vt220_tty_init);
 static void
 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
 {
-	__sclp_vt220_write((const unsigned char *) buf, count, 1, 1);
+	__sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0);
 }
 
 static struct tty_driver *