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
......@@ -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
*
* 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)
......
/*
* 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
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