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linux-next/arch/s390/kernel/cpcmd.c
Heiko Carstens 5a79859ae0 s390: remove 31 bit support
Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e58 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-03-25 11:49:33 +01:00

114 lines
2.7 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(
" sam31\n"
" diag %1,%0,0x8\n"
" sam64\n"
: "+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(
" sam31\n"
" diag %2,%0,0x8\n"
" sam64\n"
" brc 8,1f\n"
" agr %1,%4\n"
"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);