linux/arch/s390/kernel/cpcmd.c

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/*
* arch/s390/kernel/cpcmd.c
*
* S390 version
* Copyright (C) 1999,2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Christian Borntraeger (cborntra@de.ibm.com),
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <asm/ebcdic.h>
#include <asm/cpcmd.h>
#include <asm/system.h>
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
*/
int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{
const int mask = 0x40000000L;
unsigned long flags;
int return_code;
int return_len;
int cmdlen;
spin_lock_irqsave(&cpcmd_lock, flags);
cmdlen = strlen(cmd);
BUG_ON(cmdlen > 240);
memcpy(cpcmd_buf, cmd, cmdlen);
ASCEBC(cpcmd_buf, cmdlen);
if (response != NULL && rlen > 0) {
memset(response, 0, rlen);
#ifndef CONFIG_64BIT
asm volatile ( "lra 2,0(%2)\n"
"lr 4,%3\n"
"o 4,%6\n"
"lra 3,0(%4)\n"
"lr 5,%5\n"
"diag 2,4,0x8\n"
"brc 8, 1f\n"
"ar 5, %5\n"
"1: \n"
"lr %0,4\n"
"lr %1,5\n"
: "=d" (return_code), "=d" (return_len)
: "a" (cpcmd_buf), "d" (cmdlen),
"a" (response), "d" (rlen), "m" (mask)
: "cc", "2", "3", "4", "5" );
#else /* CONFIG_64BIT */
asm volatile ( "lrag 2,0(%2)\n"
"lgr 4,%3\n"
"o 4,%6\n"
"lrag 3,0(%4)\n"
"lgr 5,%5\n"
"sam31\n"
"diag 2,4,0x8\n"
"sam64\n"
"brc 8, 1f\n"
"agr 5, %5\n"
"1: \n"
"lgr %0,4\n"
"lgr %1,5\n"
: "=d" (return_code), "=d" (return_len)
: "a" (cpcmd_buf), "d" (cmdlen),
"a" (response), "d" (rlen), "m" (mask)
: "cc", "2", "3", "4", "5" );
#endif /* CONFIG_64BIT */
EBCASC(response, rlen);
} else {
return_len = 0;
#ifndef CONFIG_64BIT
asm volatile ( "lra 2,0(%1)\n"
"lr 3,%2\n"
"diag 2,3,0x8\n"
"lr %0,3\n"
: "=d" (return_code)
: "a" (cpcmd_buf), "d" (cmdlen)
: "2", "3" );
#else /* CONFIG_64BIT */
asm volatile ( "lrag 2,0(%1)\n"
"lgr 3,%2\n"
"sam31\n"
"diag 2,3,0x8\n"
"sam64\n"
"lgr %0,3\n"
: "=d" (return_code)
: "a" (cpcmd_buf), "d" (cmdlen)
: "2", "3" );
#endif /* CONFIG_64BIT */
}
spin_unlock_irqrestore(&cpcmd_lock, flags);
if (response_code != NULL)
*response_code = return_code;
return return_len;
}
EXPORT_SYMBOL(__cpcmd);
#ifdef CONFIG_64BIT
int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{
char *lowbuf;
int len;
if ((rlen == 0) || (response == NULL)
|| !((unsigned long)response >> 31))
len = __cpcmd(cmd, response, rlen, response_code);
else {
lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
if (!lowbuf) {
printk(KERN_WARNING
"cpcmd: could not allocate response buffer\n");
return -ENOMEM;
}
len = __cpcmd(cmd, lowbuf, rlen, response_code);
memcpy(response, lowbuf, rlen);
kfree(lowbuf);
}
return len;
}
EXPORT_SYMBOL(cpcmd);
#endif /* CONFIG_64BIT */