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)
{
unsigned long flags, cmdlen;
int return_code, return_len;
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) {
register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
register unsigned long reg3 asm ("3") = (addr_t) response;
register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
register unsigned long reg5 asm ("5") = rlen;
memset(response, 0, rlen);
asm volatile(
#ifndef CONFIG_64BIT
" diag %2,%0,0x8\n"
" brc 8,1f\n"
" ar %1,%4\n"
#else /* CONFIG_64BIT */
" sam31\n"
" diag %2,%0,0x8\n"
" sam64\n"
" brc 8,1f\n"
" agr %1,%4\n"
#endif /* CONFIG_64BIT */
"1:\n"
: "+d" (reg4), "+d" (reg5)
: "d" (reg2), "d" (reg3), "d" (rlen) : "cc");
return_code = (int) reg4;
return_len = (int) reg5;
EBCASC(response, rlen);
} else {
register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
register unsigned long reg3 asm ("3") = cmdlen;
return_len = 0;
asm volatile(
#ifndef CONFIG_64BIT
" diag %1,%0,0x8\n"
#else /* CONFIG_64BIT */
" sam31\n"
" diag %1,%0,0x8\n"
" sam64\n"
#endif /* CONFIG_64BIT */
: "+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;
}
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 */