linux-stable/arch/s390/kernel/cpcmd.c
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

123 lines
3 KiB
C

/*
* S390 version
* Copyright IBM Corp. 1999, 2007
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Christian Borntraeger (cborntra@de.ibm.com),
*/
#define KMSG_COMPONENT "cpcmd"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#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/io.h>
static DEFINE_SPINLOCK(cpcmd_lock);
static char cpcmd_buf[241];
static int diag8_noresponse(int cmdlen)
{
register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
register unsigned long reg3 asm ("3") = cmdlen;
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 reg3;
}
static int diag8_response(int cmdlen, char *response, int *rlen)
{
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;
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");
*rlen = reg5;
return reg4;
}
/*
* __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 cmdlen;
int rc;
int response_len;
cmdlen = strlen(cmd);
BUG_ON(cmdlen > 240);
memcpy(cpcmd_buf, cmd, cmdlen);
ASCEBC(cpcmd_buf, cmdlen);
if (response) {
memset(response, 0, rlen);
response_len = rlen;
rc = diag8_response(cmdlen, response, &rlen);
EBCASC(response, response_len);
} else {
rc = diag8_noresponse(cmdlen);
}
if (response_code)
*response_code = rc;
return rlen;
}
EXPORT_SYMBOL(__cpcmd);
int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
{
char *lowbuf;
int len;
unsigned long flags;
if ((virt_to_phys(response) != (unsigned long) response) ||
(((unsigned long)response + rlen) >> 31)) {
lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
if (!lowbuf) {
pr_warning("The cpcmd kernel function failed to "
"allocate a 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);
} else {
spin_lock_irqsave(&cpcmd_lock, flags);
len = __cpcmd(cmd, response, rlen, response_code);
spin_unlock_irqrestore(&cpcmd_lock, flags);
}
return len;
}
EXPORT_SYMBOL(cpcmd);