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[S390] cpcmd <-> __cpcmd calling issues

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In case of reipl cpcmd gets called when all other cpus are not running
anymore. To prevent deadlocks change __cpcmd so that it doesn't take
any locks and call cpcmd or __cpcmd, whatever is correct in the current
context.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2006-12-04 15:40:30 +01:00 committed by Martin Schwidefsky
parent a1a392f0b4
commit 740b5706b9
4 changed files with 24 additions and 24 deletions
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18
arch/s390/kernel/cpcmd.c
View file

@ -21,14 +21,15 @@ static DEFINE_SPINLOCK(cpcmd_lock);
static char cpcmd_buf[241];
/*
* the caller of __cpcmd has to ensure that the response buffer is below 2 GB
* __cpcmd has some restrictions over cpcmd
* - the response buffer must reside below 2GB (if any)
* - __cpcmd is unlocked and therefore not SMP-safe
*/
int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{
unsigned long flags, cmdlen;
unsigned cmdlen;
int return_code, return_len;
spin_lock_irqsave(&cpcmd_lock, flags);
cmdlen = strlen(cmd);
BUG_ON(cmdlen > 240);
memcpy(cpcmd_buf, cmd, cmdlen);
@ -74,7 +75,6 @@ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
: "+d" (reg3) : "d" (reg2) : "cc");
return_code = (int) reg3;
}
spin_unlock_irqrestore(&cpcmd_lock, flags);
if (response_code != NULL)
*response_code = return_code;
return return_len;
@ -82,15 +82,18 @@ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
EXPORT_SYMBOL(__cpcmd);
#ifdef CONFIG_64BIT
int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{
char *lowbuf;
int len;
unsigned long flags;
if ((rlen == 0) || (response == NULL)
|| !((unsigned long)response >> 31))
|| !((unsigned long)response >> 31)) {
spin_lock_irqsave(&cpcmd_lock, flags);
len = __cpcmd(cmd, response, rlen, response_code);
spin_unlock_irqrestore(&cpcmd_lock, flags);
}
else {
lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
if (!lowbuf) {
@ -98,7 +101,9 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
"cpcmd: could not allocate response buffer\n");
return -ENOMEM;
}
spin_lock_irqsave(&cpcmd_lock, flags);
len = __cpcmd(cmd, lowbuf, rlen, response_code);
spin_unlock_irqrestore(&cpcmd_lock, flags);
memcpy(response, lowbuf, rlen);
kfree(lowbuf);
}
@ -106,4 +111,3 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
}
EXPORT_SYMBOL(cpcmd);
#endif /* CONFIG_64BIT */

10
arch/s390/kernel/ipl.c
View file

@ -677,7 +677,7 @@ void do_reipl(void)
else
sprintf(buf, "IPL %X LOADPARM '%s'",
reipl_block_ccw->ipl_info.ccw.devno, loadparm);
cpcmd(buf, NULL, 0, NULL);
__cpcmd(buf, NULL, 0, NULL);
break;
case IPL_METHOD_CCW_DIAG:
diag308(DIAG308_SET, reipl_block_ccw);
@ -691,12 +691,12 @@ void do_reipl(void)
diag308(DIAG308_IPL, NULL);
break;
case IPL_METHOD_FCP_RO_VM:
cpcmd("IPL", NULL, 0, NULL);
__cpcmd("IPL", NULL, 0, NULL);
break;
case IPL_METHOD_NONE:
default:
if (MACHINE_IS_VM)
cpcmd("IPL", NULL, 0, NULL);
__cpcmd("IPL", NULL, 0, NULL);
diag308(DIAG308_IPL, NULL);
break;
}
@ -732,9 +732,9 @@ static void do_dump(void)
case IPL_METHOD_CCW_VM:
dump_smp_stop_all();
sprintf(buf, "STORE STATUS");
cpcmd(buf, NULL, 0, NULL);
__cpcmd(buf, NULL, 0, NULL);
sprintf(buf, "IPL %X", dump_block_ccw->ipl_info.ccw.devno);
cpcmd(buf, NULL, 0, NULL);
__cpcmd(buf, NULL, 0, NULL);
break;
case IPL_METHOD_CCW_DIAG:
diag308(DIAG308_SET, dump_block_ccw);

10
arch/s390/kernel/setup.c
View file

@ -229,11 +229,11 @@ static void __init conmode_default(void)
char *ptr;
if (MACHINE_IS_VM) {
__cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
ptr = strstr(query_buffer, "SUBCHANNEL =");
console_irq = simple_strtoul(ptr + 13, NULL, 16);
__cpcmd("QUERY TERM", query_buffer, 1024, NULL);
cpcmd("QUERY TERM", query_buffer, 1024, NULL);
ptr = strstr(query_buffer, "CONMODE");
/*
* Set the conmode to 3215 so that the device recognition
@ -242,7 +242,7 @@ static void __init conmode_default(void)
* 3215 and the 3270 driver will try to access the console
* device (3215 as console and 3270 as normal tty).
*/
__cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
if (ptr == NULL) {
#if defined(CONFIG_SCLP_CONSOLE)
SET_CONSOLE_SCLP;
@ -299,14 +299,14 @@ static void do_machine_restart_nonsmp(char * __unused)
static void do_machine_halt_nonsmp(void)
{
if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0)
cpcmd(vmhalt_cmd, NULL, 0, NULL);
__cpcmd(vmhalt_cmd, NULL, 0, NULL);
signal_processor(smp_processor_id(), sigp_stop_and_store_status);
}
static void do_machine_power_off_nonsmp(void)
{
if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0)
cpcmd(vmpoff_cmd, NULL, 0, NULL);
__cpcmd(vmpoff_cmd, NULL, 0, NULL);
signal_processor(smp_processor_id(), sigp_stop_and_store_status);
}

10
include/asm-s390/cpcmd.h
View file

@ -7,8 +7,8 @@
* Christian Borntraeger (cborntra@de.ibm.com),
*/
#ifndef __CPCMD__
#define __CPCMD__
#ifndef _ASM_S390_CPCMD_H
#define _ASM_S390_CPCMD_H
/*
* the lowlevel function for cpcmd
@ -16,9 +16,6 @@
*/
extern int __cpcmd(const char *cmd, char *response, int rlen, int *response_code);
#ifndef __s390x__
#define cpcmd __cpcmd
#else
/*
* cpcmd is the in-kernel interface for issuing CP commands
*
@ -33,6 +30,5 @@ extern int __cpcmd(const char *cmd, char *response, int rlen, int *response_code
* NOTE: If the response buffer is not below 2 GB, cpcmd can sleep
*/
extern int cpcmd(const char *cmd, char *response, int rlen, int *response_code);
#endif /*__s390x__*/
#endif
#endif /* _ASM_S390_CPCMD_H */