aboutsummaryrefslogtreecommitdiff
path: root/arch/s390/kernel
diff options
context:
space:
mode:
authorHeiko Carstens <heiko.carstens@de.ibm.com>2009-06-12 10:26:24 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-06-12 10:27:30 +0200
commitd90cbd469c9c7c1494fc2084af9319e6a557368b (patch)
treeefb312e668fa596a0493f5318c19d07795e3a8b0 /arch/s390/kernel
parent8c4caa4fbfc18aa50d9d682f502303a8e0d72726 (diff)
[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: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/Makefile2
-rw-r--r--arch/s390/kernel/head.S18
-rw-r--r--arch/s390/kernel/sclp.S327
3 files changed, 342 insertions, 5 deletions
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 228e3105ded..0657de7944f 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -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)
diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index bf8cf1caeff..6d227413cbe 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -1,7 +1,5 @@
/*
- * 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)
diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S
new file mode 100644
index 00000000000..20639dfe0c4
--- /dev/null
+++ b/arch/s390/kernel/sclp.S
@@ -0,0 +1,327 @@
+/*
+ * 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