Commit 740b5706 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky

[S390] cpcmd <-> __cpcmd calling issues

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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent a1a392f0
...@@ -21,14 +21,15 @@ static DEFINE_SPINLOCK(cpcmd_lock); ...@@ -21,14 +21,15 @@ static DEFINE_SPINLOCK(cpcmd_lock);
static char cpcmd_buf[241]; 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) int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{ {
unsigned long flags, cmdlen; unsigned cmdlen;
int return_code, return_len; int return_code, return_len;
spin_lock_irqsave(&cpcmd_lock, flags);
cmdlen = strlen(cmd); cmdlen = strlen(cmd);
BUG_ON(cmdlen > 240); BUG_ON(cmdlen > 240);
memcpy(cpcmd_buf, cmd, cmdlen); memcpy(cpcmd_buf, cmd, cmdlen);
...@@ -74,7 +75,6 @@ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) ...@@ -74,7 +75,6 @@ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
: "+d" (reg3) : "d" (reg2) : "cc"); : "+d" (reg3) : "d" (reg2) : "cc");
return_code = (int) reg3; return_code = (int) reg3;
} }
spin_unlock_irqrestore(&cpcmd_lock, flags);
if (response_code != NULL) if (response_code != NULL)
*response_code = return_code; *response_code = return_code;
return return_len; return return_len;
...@@ -82,15 +82,18 @@ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) ...@@ -82,15 +82,18 @@ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
EXPORT_SYMBOL(__cpcmd); EXPORT_SYMBOL(__cpcmd);
#ifdef CONFIG_64BIT
int cpcmd(const char *cmd, char *response, int rlen, int *response_code) int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{ {
char *lowbuf; char *lowbuf;
int len; int len;
unsigned long flags;
if ((rlen == 0) || (response == NULL) 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); len = __cpcmd(cmd, response, rlen, response_code);
spin_unlock_irqrestore(&cpcmd_lock, flags);
}
else { else {
lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
if (!lowbuf) { if (!lowbuf) {
...@@ -98,7 +101,9 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code) ...@@ -98,7 +101,9 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
"cpcmd: could not allocate response buffer\n"); "cpcmd: could not allocate response buffer\n");
return -ENOMEM; return -ENOMEM;
} }
spin_lock_irqsave(&cpcmd_lock, flags);
len = __cpcmd(cmd, lowbuf, rlen, response_code); len = __cpcmd(cmd, lowbuf, rlen, response_code);
spin_unlock_irqrestore(&cpcmd_lock, flags);
memcpy(response, lowbuf, rlen); memcpy(response, lowbuf, rlen);
kfree(lowbuf); kfree(lowbuf);
} }
...@@ -106,4 +111,3 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code) ...@@ -106,4 +111,3 @@ int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
} }
EXPORT_SYMBOL(cpcmd); EXPORT_SYMBOL(cpcmd);
#endif /* CONFIG_64BIT */
...@@ -677,7 +677,7 @@ void do_reipl(void) ...@@ -677,7 +677,7 @@ void do_reipl(void)
else else
sprintf(buf, "IPL %X LOADPARM '%s'", sprintf(buf, "IPL %X LOADPARM '%s'",
reipl_block_ccw->ipl_info.ccw.devno, loadparm); reipl_block_ccw->ipl_info.ccw.devno, loadparm);
cpcmd(buf, NULL, 0, NULL); __cpcmd(buf, NULL, 0, NULL);
break; break;
case IPL_METHOD_CCW_DIAG: case IPL_METHOD_CCW_DIAG:
diag308(DIAG308_SET, reipl_block_ccw); diag308(DIAG308_SET, reipl_block_ccw);
...@@ -691,12 +691,12 @@ void do_reipl(void) ...@@ -691,12 +691,12 @@ void do_reipl(void)
diag308(DIAG308_IPL, NULL); diag308(DIAG308_IPL, NULL);
break; break;
case IPL_METHOD_FCP_RO_VM: case IPL_METHOD_FCP_RO_VM:
cpcmd("IPL", NULL, 0, NULL); __cpcmd("IPL", NULL, 0, NULL);
break; break;
case IPL_METHOD_NONE: case IPL_METHOD_NONE:
default: default:
if (MACHINE_IS_VM) if (MACHINE_IS_VM)
cpcmd("IPL", NULL, 0, NULL); __cpcmd("IPL", NULL, 0, NULL);
diag308(DIAG308_IPL, NULL); diag308(DIAG308_IPL, NULL);
break; break;
} }
...@@ -732,9 +732,9 @@ static void do_dump(void) ...@@ -732,9 +732,9 @@ static void do_dump(void)
case IPL_METHOD_CCW_VM: case IPL_METHOD_CCW_VM:
dump_smp_stop_all(); dump_smp_stop_all();
sprintf(buf, "STORE STATUS"); 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); sprintf(buf, "IPL %X", dump_block_ccw->ipl_info.ccw.devno);
cpcmd(buf, NULL, 0, NULL); __cpcmd(buf, NULL, 0, NULL);
break; break;
case IPL_METHOD_CCW_DIAG: case IPL_METHOD_CCW_DIAG:
diag308(DIAG308_SET, dump_block_ccw); diag308(DIAG308_SET, dump_block_ccw);
......
...@@ -229,11 +229,11 @@ static void __init conmode_default(void) ...@@ -229,11 +229,11 @@ static void __init conmode_default(void)
char *ptr; char *ptr;
if (MACHINE_IS_VM) { 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); console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
ptr = strstr(query_buffer, "SUBCHANNEL ="); ptr = strstr(query_buffer, "SUBCHANNEL =");
console_irq = simple_strtoul(ptr + 13, NULL, 16); 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"); ptr = strstr(query_buffer, "CONMODE");
/* /*
* Set the conmode to 3215 so that the device recognition * Set the conmode to 3215 so that the device recognition
...@@ -242,7 +242,7 @@ static void __init conmode_default(void) ...@@ -242,7 +242,7 @@ static void __init conmode_default(void)
* 3215 and the 3270 driver will try to access the console * 3215 and the 3270 driver will try to access the console
* device (3215 as console and 3270 as normal tty). * 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 (ptr == NULL) {
#if defined(CONFIG_SCLP_CONSOLE) #if defined(CONFIG_SCLP_CONSOLE)
SET_CONSOLE_SCLP; SET_CONSOLE_SCLP;
...@@ -299,14 +299,14 @@ static void do_machine_restart_nonsmp(char * __unused) ...@@ -299,14 +299,14 @@ static void do_machine_restart_nonsmp(char * __unused)
static void do_machine_halt_nonsmp(void) static void do_machine_halt_nonsmp(void)
{ {
if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0) 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); signal_processor(smp_processor_id(), sigp_stop_and_store_status);
} }
static void do_machine_power_off_nonsmp(void) static void do_machine_power_off_nonsmp(void)
{ {
if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0) 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); signal_processor(smp_processor_id(), sigp_stop_and_store_status);
} }
......
...@@ -7,8 +7,8 @@ ...@@ -7,8 +7,8 @@
* Christian Borntraeger (cborntra@de.ibm.com), * Christian Borntraeger (cborntra@de.ibm.com),
*/ */
#ifndef __CPCMD__ #ifndef _ASM_S390_CPCMD_H
#define __CPCMD__ #define _ASM_S390_CPCMD_H
/* /*
* the lowlevel function for cpcmd * the lowlevel function for cpcmd
...@@ -16,9 +16,6 @@ ...@@ -16,9 +16,6 @@
*/ */
extern int __cpcmd(const char *cmd, char *response, int rlen, int *response_code); 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 * 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 ...@@ -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 * 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); extern int cpcmd(const char *cmd, char *response, int rlen, int *response_code);
#endif /*__s390x__*/
#endif #endif /* _ASM_S390_CPCMD_H */
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