From: Heiko Carstens Date: Mon, 4 Dec 2006 14:40:30 +0000 (+0100) Subject: [S390] cpcmd <-> __cpcmd calling issues X-Git-Tag: v2.6.20-rc1~34^2~40^2~15^2~16 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=740b5706b9c4b3767f597b3ea76654c6f2a800b2;p=linux-2.6 [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 Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/kernel/cpcmd.c b/arch/s390/kernel/cpcmd.c index 1eae74e72f..a5972f1541 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 77f4aff630..101b003cfa 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 2aa13e8e00..9bbef0c655 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); } diff --git a/include/asm-s390/cpcmd.h b/include/asm-s390/cpcmd.h index 1fcf65be7a..48a9eab164 100644 --- a/include/asm-s390/cpcmd.h +++ b/include/asm-s390/cpcmd.h @@ -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 */