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>
This commit is contained in:
Martin Schwidefsky 2015-07-08 10:20:04 +02:00
parent 1d2334cb7d
commit 22362a0e23
7 changed files with 186 additions and 356 deletions

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@ -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)

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@ -232,6 +232,17 @@ static inline void __load_psw_mask (unsigned long mask)
: "=&d" (addr), "=Q" (psw) : "Q" (psw) : "memory", "cc");
}
/*
* 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.
*/

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@ -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 */

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@ -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

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@ -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)

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@ -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

160
arch/s390/kernel/sclp.c Normal file
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@ -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);
}