linux/arch/s390/kernel/sclp.S
Heiko Carstens 99e639b791 s390/sclp: fix addressing mode clobber
The early mini sclp driver may be called in zArch mode either in
31 or 64 bit addressing mode.
If called in 31 bit addressing mode the new external interrupt psw
however would switch to 64 bit addressing mode. This would cause an
addressing exception within the interrupt handler, since the code
didn't expect the zArch/31 bit addressing mode combination.

Fix this by setting the new psw addressing mode bits so they fit
the current addressing mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-06 22:39:51 +01:00

360 lines
8.1 KiB
ArmAsm

/*
* 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>
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)
#ifdef CONFIG_64BIT
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:
#endif
mvc .LoldpswS1-.LbaseS1(16,%r13),0(%r8)
mvc 0(16,%r8),0(%r9)
#ifdef CONFIG_64BIT
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)
#endif
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(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
#ifdef CONFIG_64BIT
.LextpswS1_64:
.quad 0, .LwaitS1 # PSW to handle ext int, 64 bit
#endif
.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 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
#ifdef CONFIG_64BIT
tm LC_AR_MODE_ID,1
jno .Lesa2
ahi %r15,-80
stmh %r6,%r15,96(%r15) # store upper register halves
.Lesa2:
#endif
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:
#ifdef CONFIG_64BIT
tm LC_AR_MODE_ID,1
jno .Lesa3
lmh %r6,%r15,96(%r15) # store upper register halves
ahi %r15,80
.Lesa3:
#endif
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
.section .data,"aw",@progbits
.balign 4096
_sclp_work_area:
.fill 4096
.previous