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authorHeiko Carstens <heiko.carstens@de.ibm.com>2006-12-04 15:40:30 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-12-04 15:40:30 +0100
commit740b5706b9c4b3767f597b3ea76654c6f2a800b2 (patch)
tree370dc09ec8f3abaecc742003ed9d28eecf636c3b /arch/s390
parenta1a392f0b4f27604811bf8aa8d7636b3b4bc3803 (diff)
[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: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/cpcmd.c18
-rw-r--r--arch/s390/kernel/ipl.c10
-rw-r--r--arch/s390/kernel/setup.c10
3 files changed, 21 insertions, 17 deletions
diff --git a/arch/s390/kernel/cpcmd.c b/arch/s390/kernel/cpcmd.c
index 1eae74e72f9..a5972f1541f 100644
--- a/arch/s390/kernel/cpcmd.c
+++ b/arch/s390/kernel/cpcmd.c
@@ -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 */
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 77f4aff630f..101b003cfab 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -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);
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2aa13e8e000..9bbef0c6558 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -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);
}