s390/sclp: convert early sclp console code to C

The 31-bit assembler code for the early sclp console is error
prone as git commit fde24b54d976cc123506695c17db01438a11b673
"s390/sclp: clear upper register halves in _sclp_print_early"
has shown.

Convert the assembler code to C.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

7 files changed, 186 insertions, 356 deletions

diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 667b1bca5681..e8d4423e4f85 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -33,6 +33,8 @@ mflags-$(CONFIG_MARCH_Z196)   := -march=z196
 mflags-$(CONFIG_MARCH_ZEC12)  := -march=zEC12
 mflags-$(CONFIG_MARCH_Z13)   := -march=z13
 
+export CC_FLAGS_MARCH := $(mflags-y)
+
 aflags-y += $(mflags-y)
 cflags-y += $(mflags-y)
 
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index c417015c5304..085fb0d3c54e 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -233,6 +233,17 @@ static inline void __load_psw_mask (unsigned long mask)
 }
 
 /*
+ * Extract current PSW mask
+ */
+static inline unsigned long __extract_psw(void)
+{
+	unsigned int reg1, reg2;
+
+	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
+	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
+}
+
+/*
  * Rewind PSW instruction address by specified number of bytes.
  */
 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index f6ff06077631..821dde5f425d 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -79,6 +79,6 @@ int sclp_pci_configure(u32 fid);
 int sclp_pci_deconfigure(u32 fid);
 int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode);
 void sclp_early_detect(void);
-long _sclp_print_early(const char *);
+int _sclp_print_early(const char *);
 
 #endif /* _ASM_S390_SCLP_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index ffb87617a36c..b756c6348ac6 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -28,6 +28,17 @@ CFLAGS_ptrace.o		+= -DUTS_MACHINE='"$(UTS_MACHINE)"'
 
 CFLAGS_sysinfo.o += -w
 
+#
+# Use -march=z900 for sclp.c to be able to print an error message if
+# the kernel is started on a machine which is too old
+#
+CFLAGS_REMOVE_sclp.o = $(CC_FLAGS_FTRACE)
+ifneq ($(CC_FLAGS_MARCH),-march=z900)
+CFLAGS_REMOVE_sclp.o += $(CC_FLAGS_MARCH)
+CFLAGS_sclp.o	+= -march=z900
+endif
+GCOV_PROFILE_sclp.o := n
+
 obj-y	:= traps.o time.o process.o base.o early.o setup.o idle.o vtime.o
 obj-y	+= processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
 obj-y	+= debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o
diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index 59b7c6470567..63c77fdb619e 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -370,6 +370,7 @@ ENTRY(startup_kdump)
 	xc	0x200(256),0x200	# partially clear lowcore
 	xc	0x300(256),0x300
 	xc	0xe00(256),0xe00
+	lctlg	%c0,%c15,0x200(%r0)	# initialize control registers
 	stck	__LC_LAST_UPDATE_CLOCK
 	spt	6f-.LPG0(%r13)
 	mvc	__LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S
deleted file mode 100644
index ada0c07fe1a8..000000000000
--- a/arch/s390/kernel/sclp.S
+++ /dev/null
@@ -1,355 +0,0 @@
-/*
- * Mini SCLP driver.
- *
- * Copyright IBM Corp. 2004, 2009
- *
- *   Author(s):	Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>,
- *		Heiko Carstens <heiko.carstens@de.ibm.com>,
- *
- */
-
-#include <linux/linkage.h>
-#include <asm/irq.h>
-
-LC_EXT_NEW_PSW		= 0x58			# addr of ext int handler
-LC_EXT_NEW_PSW_64	= 0x1b0			# addr of ext int handler 64 bit
-LC_EXT_INT_PARAM	= 0x80			# addr of ext int parameter
-LC_EXT_INT_CODE		= 0x86			# addr of ext int code
-LC_AR_MODE_ID		= 0xa3
-
-#
-# Subroutine which waits synchronously until either an external interruption
-# or a timeout occurs.
-#
-# Parameters:
-#   R2	= 0 for no timeout, non-zero for timeout in (approximated) seconds
-#
-# Returns:
-#   R2	= 0 on interrupt, 2 on timeout
-#   R3	= external interruption parameter if R2=0
-#
-
-_sclp_wait_int:
-	stm	%r6,%r15,24(%r15)		# save registers
-	basr	%r13,0				# get base register
-.LbaseS1:
-	ahi	%r15,-96			# create stack frame
-	la	%r8,LC_EXT_NEW_PSW		# register int handler
-	la	%r9,.LextpswS1-.LbaseS1(%r13)
-	tm	LC_AR_MODE_ID,1
-	jno	.Lesa1
-	la	%r8,LC_EXT_NEW_PSW_64		# register int handler 64 bit
-	la	%r9,.LextpswS1_64-.LbaseS1(%r13)
-.Lesa1:
-	mvc	.LoldpswS1-.LbaseS1(16,%r13),0(%r8)
-	mvc	0(16,%r8),0(%r9)
-	epsw	%r6,%r7				# set current addressing mode
-	nill	%r6,0x1				# in new psw (31 or 64 bit mode)
-	nilh	%r7,0x8000
-	stm	%r6,%r7,0(%r8)
-	lhi	%r6,0x0200			# cr mask for ext int (cr0.54)
-	ltr	%r2,%r2
-	jz	.LsetctS1
-	ahi	%r6,0x0800			# cr mask for clock int (cr0.52)
-	stck	.LtimeS1-.LbaseS1(%r13)		# initiate timeout
-	al	%r2,.LtimeS1-.LbaseS1(%r13)
-	st	%r2,.LtimeS1-.LbaseS1(%r13)
-	sckc	.LtimeS1-.LbaseS1(%r13)
-
-.LsetctS1:
-	stctl	%c0,%c0,.LctlS1-.LbaseS1(%r13)	# enable required interrupts
-	l	%r0,.LctlS1-.LbaseS1(%r13)
-	lhi	%r1,~(0x200 | 0x800)		# clear old values
-	nr	%r1,%r0
-	or	%r1,%r6				# set new value
-	st	%r1,.LctlS1-.LbaseS1(%r13)
-	lctl	%c0,%c0,.LctlS1-.LbaseS1(%r13)
-	st	%r0,.LctlS1-.LbaseS1(%r13)
-	lhi	%r2,2				# return code for timeout
-.LloopS1:
-	lpsw	.LwaitpswS1-.LbaseS1(%r13)	# wait until interrupt
-.LwaitS1:
-	lh	%r7,LC_EXT_INT_CODE
-	chi	%r7,EXT_IRQ_CLK_COMP		# timeout?
-	je	.LtimeoutS1
-	chi	%r7,EXT_IRQ_SERVICE_SIG		# service int?
-	jne	.LloopS1
-	sr	%r2,%r2
-	l	%r3,LC_EXT_INT_PARAM
-.LtimeoutS1:
-	lctl	%c0,%c0,.LctlS1-.LbaseS1(%r13)	# restore interrupt setting
-	# restore old handler
-	mvc	0(16,%r8),.LoldpswS1-.LbaseS1(%r13)
-	lm	%r6,%r15,120(%r15)		# restore registers
-	br	%r14				# return to caller
-
-	.align	8
-.LoldpswS1:
-	.long	0, 0, 0, 0			# old ext int PSW
-.LextpswS1:
-	.long	0x00080000, 0x80000000+.LwaitS1	# PSW to handle ext int
-.LextpswS1_64:
-	.quad	0, .LwaitS1			# PSW to handle ext int, 64 bit
-.LwaitpswS1:
-	.long	0x010a0000, 0x00000000+.LloopS1	# PSW to wait for ext int
-.LtimeS1:
-	.quad	0				# current time
-.LctlS1:
-	.long	0				# CT0 contents
-
-#
-# Subroutine to synchronously issue a service call.
-#
-# Parameters:
-#   R2	= command word
-#   R3	= sccb address
-#
-# Returns:
-#   R2	= 0 on success, 1 on failure
-#   R3	= sccb response code if R2 = 0
-#
-
-_sclp_servc:
-	stm	%r6,%r15,24(%r15)		# save registers
-	ahi	%r15,-96			# create stack frame
-	lr	%r6,%r2				# save command word
-	lr	%r7,%r3				# save sccb address
-.LretryS2:
-	lhi	%r2,1				# error return code
-	.insn	rre,0xb2200000,%r6,%r7		# servc
-	brc	1,.LendS2			# exit if not operational
-	brc	8,.LnotbusyS2			# go on if not busy
-	sr	%r2,%r2				# wait until no longer busy
-	bras	%r14,_sclp_wait_int
-	j	.LretryS2			# retry
-.LnotbusyS2:
-	sr	%r2,%r2				# wait until result
-	bras	%r14,_sclp_wait_int
-	sr	%r2,%r2
-	lh	%r3,6(%r7)
-.LendS2:
-	lm	%r6,%r15,120(%r15)		# restore registers
-	br	%r14
-
-#
-# Subroutine to set up the SCLP interface.
-#
-# Parameters:
-#   R2	= 0 to activate, non-zero to deactivate
-#
-# Returns:
-#   R2	= 0 on success, non-zero on failure
-#
-
-_sclp_setup:
-	stm	%r6,%r15,24(%r15)		# save registers
-	ahi	%r15,-96			# create stack frame
-	basr	%r13,0				# get base register
-.LbaseS3:
-	l	%r6,.LsccbS0-.LbaseS3(%r13)	# prepare init mask sccb
-	mvc	0(.LinitendS3-.LinitsccbS3,%r6),.LinitsccbS3-.LbaseS3(%r13)
-	ltr	%r2,%r2				# initialization?
-	jz	.LdoinitS3			# go ahead
-	# clear masks
-	xc	.LinitmaskS3-.LinitsccbS3(8,%r6),.LinitmaskS3-.LinitsccbS3(%r6)
-.LdoinitS3:
-	l	%r2,.LwritemaskS3-.LbaseS3(%r13)# get command word
-	lr	%r3,%r6				# get sccb address
-	bras	%r14,_sclp_servc		# issue service call
-	ltr	%r2,%r2				# servc successful?
-	jnz	.LerrorS3
-	chi	%r3,0x20			# write mask successful?
-	jne	.LerrorS3
-	# check masks
-	la	%r2,.LinitmaskS3-.LinitsccbS3(%r6)
-	l	%r1,0(%r2)			# receive mask ok?
-	n	%r1,12(%r2)
-	cl	%r1,0(%r2)
-	jne	.LerrorS3
-	l	%r1,4(%r2)			# send mask ok?
-	n	%r1,8(%r2)
-	cl	%r1,4(%r2)
-	sr	%r2,%r2
-	je	.LendS3
-.LerrorS3:
-	lhi	%r2,1				# error return code
-.LendS3:
-	lm	%r6,%r15,120(%r15)		# restore registers
-	br	%r14
-.LwritemaskS3:
-	.long	0x00780005			# SCLP command for write mask
-.LinitsccbS3:
-	.word	.LinitendS3-.LinitsccbS3
-	.byte	0,0,0,0
-	.word	0
-	.word	0
-	.word	4
-.LinitmaskS3:
-	.long	0x80000000
-	.long	0x40000000
-	.long	0
-	.long	0
-.LinitendS3:
-
-#
-# Subroutine which prints a given text to the SCLP console.
-#
-# Parameters:
-#   R2	= address of nil-terminated ASCII text
-#
-# Returns:
-#   R2	= 0 on success, 1 on failure
-#
-
-_sclp_print:
-	stm	%r6,%r15,24(%r15)		# save registers
-	ahi	%r15,-96			# create stack frame
-	basr	%r13,0				# get base register
-.LbaseS4:
-	l	%r8,.LsccbS0-.LbaseS4(%r13)	# prepare write data sccb
-	mvc	0(.LmtoS4-.LwritesccbS4,%r8),.LwritesccbS4-.LbaseS4(%r13)
-	la	%r7,.LmtoS4-.LwritesccbS4(%r8)	# current mto addr
-	sr	%r0,%r0
-	l	%r10,.Lascebc-.LbaseS4(%r13)	# address of translation table
-.LinitmtoS4:
-	# initialize mto
-	mvc	0(.LmtoendS4-.LmtoS4,%r7),.LmtoS4-.LbaseS4(%r13)
-	lhi	%r6,.LmtoendS4-.LmtoS4		# current mto length
-.LloopS4:
-	ic	%r0,0(%r2)			# get character
-	ahi	%r2,1
-	ltr	%r0,%r0				# end of string?
-	jz	.LfinalizemtoS4
-	chi	%r0,0x0a			# end of line (NL)?
-	jz	.LfinalizemtoS4
-	stc	%r0,0(%r6,%r7)			# copy to mto
-	la	%r11,0(%r6,%r7)
-	tr	0(1,%r11),0(%r10)		# translate to EBCDIC
-	ahi	%r6,1
-	j	.LloopS4
-.LfinalizemtoS4:
-	sth	%r6,0(%r7)			# update mto length
-	lh	%r9,.LmdbS4-.LwritesccbS4(%r8)	# update mdb length
-	ar	%r9,%r6
-	sth	%r9,.LmdbS4-.LwritesccbS4(%r8)
-	lh	%r9,.LevbufS4-.LwritesccbS4(%r8)# update evbuf length
-	ar	%r9,%r6
-	sth	%r9,.LevbufS4-.LwritesccbS4(%r8)
-	lh	%r9,0(%r8)			# update sccb length
-	ar	%r9,%r6
-	sth	%r9,0(%r8)
-	ar	%r7,%r6				# update current mto address
-	ltr	%r0,%r0				# more characters?
-	jnz	.LinitmtoS4
-	l	%r2,.LwritedataS4-.LbaseS4(%r13)# write data
-	lr	%r3,%r8
-	bras	%r14,_sclp_servc
-	ltr	%r2,%r2				# servc successful?
-	jnz	.LendS4
-	chi	%r3,0x20			# write data successful?
-	je	.LendS4
-	lhi	%r2,1				# error return code
-.LendS4:
-	lm	%r6,%r15,120(%r15)		# restore registers
-	br	%r14
-
-#
-# Function which prints a given text to the SCLP console.
-#
-# Parameters:
-#   R2	= address of nil-terminated ASCII text
-#
-# Returns:
-#   R2	= 0 on success, 1 on failure
-#
-
-ENTRY(_sclp_print_early)
-	stm	%r6,%r15,24(%r15)		# save registers
-	ahi	%r15,-96			# create stack frame
-	tm	LC_AR_MODE_ID,1
-	jno	.Lesa2
-	ahi	%r15,-80
-	stmh	%r6,%r15,96(%r15)		# store upper register halves
-	basr	%r13,0
-	lmh	%r0,%r15,.Lzeroes-.(%r13)	# clear upper register halves
-.Lesa2:
-	lr	%r10,%r2			# save string pointer
-	lhi	%r2,0
-	bras	%r14,_sclp_setup		# enable console
-	ltr	%r2,%r2
-	jnz	.LendS5
-	lr	%r2,%r10
-	bras	%r14,_sclp_print		# print string
-	ltr	%r2,%r2
-	jnz	.LendS5
-	lhi	%r2,1
-	bras	%r14,_sclp_setup		# disable console
-.LendS5:
-	tm	LC_AR_MODE_ID,1
-	jno	.Lesa3
-	lgfr	%r2,%r2				# sign extend return value
-	lmh	%r6,%r15,96(%r15)		# restore upper register halves
-	ahi	%r15,80
-.Lesa3:
-	lm	%r6,%r15,120(%r15)		# restore registers
-	br	%r14
-.Lzeroes:
-	.fill	64,4,0
-
-.LwritedataS4:
-	.long	0x00760005			# SCLP command for write data
-.LwritesccbS4:
-	# sccb
-	.word	.LmtoS4-.LwritesccbS4
-	.byte	0
-	.byte	0,0,0
-	.word	0
-
-	# evbuf
-.LevbufS4:
-	.word	.LmtoS4-.LevbufS4
-	.byte	0x02
-	.byte	0
-	.word	0
-
-.LmdbS4:
-	# mdb
-	.word	.LmtoS4-.LmdbS4
-	.word	1
-	.long	0xd4c4c240
-	.long	1
-
-	# go
-.LgoS4:
-	.word	.LmtoS4-.LgoS4
-	.word	1
-	.long	0
-	.byte	0,0,0,0,0,0,0,0
-	.byte	0,0,0
-	.byte	0
-	.byte	0,0,0,0,0,0,0
-	.byte	0
-	.word	0
-	.byte	0,0,0,0,0,0,0,0,0,0
-	.byte	0,0,0,0,0,0,0,0
-	.byte	0,0,0,0,0,0,0,0
-
-.LmtoS4:
-	.word	.LmtoendS4-.LmtoS4
-	.word	4
-	.word	0x1000
-	.byte	0
-	.byte	0,0,0
-.LmtoendS4:
-
-	# Global constants
-.LsccbS0:
-	.long	_sclp_work_area
-.Lascebc:
-	.long	_ascebc
-
-.section .data,"aw",@progbits
-	.balign 4096
-_sclp_work_area:
-	.fill	4096
-.previous
diff --git a/arch/s390/kernel/sclp.c b/arch/s390/kernel/sclp.c
new file mode 100644
index 000000000000..fa0bdff1d413
--- /dev/null
+++ b/arch/s390/kernel/sclp.c
@@ -0,0 +1,160 @@
+/*
+ *    Copyright IBM Corp. 2015
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+#include <linux/kernel.h>
+#include <asm/ebcdic.h>
+#include <asm/irq.h>
+#include <asm/lowcore.h>
+#include <asm/processor.h>
+#include <asm/sclp.h>
+
+static char _sclp_work_area[4096] __aligned(PAGE_SIZE);
+
+static void _sclp_wait_int(void)
+{
+	unsigned long cr0, cr0_new, psw_mask, addr;
+	psw_t psw_ext_save, psw_wait;
+
+	__ctl_store(cr0, 0, 0);
+	cr0_new = cr0 | 0x200;
+	__ctl_load(cr0_new, 0, 0);
+
+	psw_ext_save = S390_lowcore.external_new_psw;
+	psw_mask = __extract_psw() & (PSW_MASK_EA | PSW_MASK_BA);
+	S390_lowcore.external_new_psw.mask = psw_mask;
+	psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
+	S390_lowcore.ext_int_code = 0;
+
+	do {
+		asm volatile(
+			"	larl	%[addr],0f\n"
+			"	stg	%[addr],%[psw_wait_addr]\n"
+			"	stg	%[addr],%[psw_ext_addr]\n"
+			"	lpswe	%[psw_wait]\n"
+			"0:\n"
+			: [addr] "=&d" (addr),
+			  [psw_wait_addr] "=Q" (psw_wait.addr),
+			  [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
+			: [psw_wait] "Q" (psw_wait)
+			: "cc", "memory");
+	} while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
+
+	__ctl_load(cr0, 0, 0);
+	S390_lowcore.external_new_psw = psw_ext_save;
+}
+
+static int _sclp_servc(unsigned int cmd, char *sccb)
+{
+	unsigned int cc;
+
+	do {
+		asm volatile(
+			"	.insn	rre,0xb2200000,%1,%2\n"
+			"	ipm	%0\n"
+			: "=d" (cc) : "d" (cmd), "a" (sccb)
+			: "cc", "memory");
+		cc >>= 28;
+		if (cc == 3)
+			return -EINVAL;
+		_sclp_wait_int();
+	} while (cc != 0);
+	return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
+}
+
+static int _sclp_setup(int disable)
+{
+	static unsigned char init_sccb[] = {
+		0x00, 0x1c,
+		0x00, 0x00, 0x00, 0x00,	0x00, 0x00, 0x00, 0x00,
+		0x00, 0x04,
+		0x80, 0x00, 0x00, 0x00,	0x40, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00,	0x00, 0x00, 0x00, 0x00
+	};
+	unsigned int *masks;
+	int rc;
+
+	memcpy(_sclp_work_area, init_sccb, 28);
+	masks = (unsigned int *)(_sclp_work_area + 12);
+	if (disable)
+		memset(masks, 0, 16);
+	/* SCLP write mask */
+	rc = _sclp_servc(0x00780005, _sclp_work_area);
+	if (rc)
+		return rc;
+	if ((masks[0] & masks[3]) != masks[0] ||
+	    (masks[1] & masks[2]) != masks[1])
+		return -EIO;
+	return 0;
+}
+
+static int _sclp_print(const char *str)
+{
+	static unsigned char write_head[] = {
+		/* sccb header */
+		0x00, 0x52,					/* 0 */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00,		/* 2 */
+		/* evbuf */
+		0x00, 0x4a,					/* 8 */
+		0x02, 0x00, 0x00, 0x00,				/* 10 */
+		/* mdb */
+		0x00, 0x44,					/* 14 */
+		0x00, 0x01,					/* 16 */
+		0xd4, 0xc4, 0xc2, 0x40,				/* 18 */
+		0x00, 0x00, 0x00, 0x01,				/* 22 */
+		/* go */
+		0x00, 0x38,					/* 26 */
+		0x00, 0x01,					/* 28 */
+		0x00, 0x00, 0x00, 0x00,				/* 30 */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 34 */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 42 */
+		0x00, 0x00, 0x00, 0x00,				/* 50 */
+		0x00, 0x00,					/* 54 */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 56 */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 64 */
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 72 */
+		0x00, 0x00,					/* 80 */
+	};
+	static unsigned char write_mto[] = {
+		/* mto	*/
+		0x00, 0x0a,					/* 0 */
+		0x00, 0x04,					/* 2 */
+		0x10, 0x00,					/* 4 */
+		0x00, 0x00, 0x00, 0x00				/* 6 */
+	};
+	unsigned char *ptr, ch;
+	unsigned int count;
+
+	memcpy(_sclp_work_area, write_head, sizeof(write_head));
+	ptr = _sclp_work_area + sizeof(write_head);
+	do {
+		memcpy(ptr, write_mto, sizeof(write_mto));
+		for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
+			if (ch == 0x0a)
+				break;
+			ptr[count] = _ascebc[ch];
+		}
+		/* Update length fields in mto, mdb, evbuf and sccb */
+		*(unsigned short *) ptr = count;
+		*(unsigned short *)(_sclp_work_area + 14) += count;
+		*(unsigned short *)(_sclp_work_area + 8) += count;
+		*(unsigned short *)(_sclp_work_area + 0) += count;
+		ptr += count;
+	} while (ch != 0);
+
+	/* SCLP write data */
+	return _sclp_servc(0x00760005, _sclp_work_area);
+}
+
+int _sclp_print_early(const char *str)
+{
+	int rc;
+
+	rc = _sclp_setup(0);
+	if (rc)
+		return rc;
+	rc = _sclp_print(str);
+	if (rc)
+		return rc;
+	return _sclp_setup(1);
+}