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Commit d90cbd46 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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[S390] add mini sclp driver 



This adds a mini sclp device driver for very early use. The primary
and probably only use will be to emit a message to the console if the
cpu doesn't provide the minimum required capabilities to run the kernel.
After printing the message a disabled wait will be loaded and the
machine stops operating.
Printing the message is also part of this patch.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 8c4caa4f

arch/s390/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w 
obj-y	:=  bitmap.o traps.o time.o process.o base.o early.o setup.o \

	    processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o \

	    s390_ext.o debug.o irq.o ipl.o dis.o diag.o mem_detect.o \

	    vdso.o vtime.o sysinfo.o nmi.o

	    vdso.o vtime.o sysinfo.o nmi.o sclp.o



obj-y	+= $(if $(CONFIG_64BIT),entry64.o,entry.o)

obj-y	+= $(if $(CONFIG_64BIT),reipl64.o,reipl.o)

arch/s390/kernel/head.S

+14 −4
Original line number Diff line number Diff line 
/*

 *  arch/s390/kernel/head.S

 *

 * Copyright (C) IBM Corp. 1999,2006

 * Copyright IBM Corp. 1999,2009

 *

 *    Author(s): Hartmut Penner <hp@de.ibm.com>

 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
@@ -494,7 +492,19 @@ startup:basr %r13,0 # get base 
	n	%r0,2f+12-.LPG0(%r13)

	cl	%r0,2f+12-.LPG0(%r13)

	je	3f

1:	lpsw	2f-.LPG0(13)		# machine type not good enough, crash

1:	l	%r15,.Lstack-.LPG0(%r13)

	ahi	%r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE

	ahi	%r15,-96

	la	%r2,.Lals_string-.LPG0(%r13)

	l	%r3,.Lsclp_print-.LPG0(%r13)

	basr	%r14,%r3

	lpsw	2f-.LPG0(%r13)		# machine type not good enough, crash

.Lals_string:

	.asciz	"The Linux kernel requires more recent processor hardware"

.Lsclp_print:

	.long	_sclp_print_early

.Lstack:

	.long	init_thread_union

	.align 16

2:	.long	0x000a0000,0x8badcccc

#if defined(CONFIG_64BIT)

arch/s390/kernel/sclp.S

0 → 100644
+327 −0
Original line number Diff line number Diff line 
/*

 * Mini SCLP driver.

 *

 * Copyright IBM Corp. 2004,2009

 *

 *   Author(s):	Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>,

 *		Heiko Carstens <heiko.carstens@de.ibm.com>,

 *

 */



LC_EXT_NEW_PSW		= 0x58			# addr of ext int handler

LC_EXT_INT_PARAM	= 0x80			# addr of ext int parameter

LC_EXT_INT_CODE		= 0x86			# addr of ext int code



#

# 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

#



.section ".init.text","ax"



_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

	mvc	.LoldpswS1-.LbaseS1(8,%r13),0(%r8)

	mvc	0(8,%r8),.LextpswS1-.LbaseS1(%r13)

	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	%r7,0x1004			# timeout?

	je	.LtimeoutS1

	chi	%r7,0x2401			# 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(8,%r8),.LoldpswS1-.LbaseS1(%r13)

	lm	%r6,%r15,120(%r15)		# restore registers

	br	%r14				# return to caller



	.align	8

.LoldpswS1:

	.long	0, 0				# old ext int PSW

.LextpswS1:

	.long	0x00080000, 0x80000000+.LwaitS1	# PSW to handle ext int

.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	%r0,0x15			# 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 adress

	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

#



	.globl _sclp_print_early

_sclp_print_early:

	stm	%r6,%r15,24(%r15)		# save registers

	ahi	%r15,-96			# create stack frame

	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:

	lm	%r6,%r15,120(%r15)		# restore registers

	br	%r14



.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

.previous



.section ".init.data","a"

	.balign 4096

_sclp_work_area:

	.fill	4096

.previous