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// SPDX-License-Identifier: GPL-2.0
/*
* 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/export.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <asm/diag.h>
#include <asm/ebcdic.h>
#include <asm/cpcmd.h>
static DEFINE_SPINLOCK(cpcmd_lock);
static char cpcmd_buf[241];
static int diag8_noresponse(int cmdlen)
{
asm volatile(
" diag %[rx],%[ry],0x8\n"
: [ry] "+&d" (cmdlen)
: [rx] "d" (__pa(cpcmd_buf))
: "cc");
return cmdlen;
}
static int diag8_response(int cmdlen, char *response, int *rlen)
{
union register_pair rx, ry;
int cc;
rx.even = __pa(cpcmd_buf);
rx.odd = __pa(response);
ry.even = cmdlen | 0x40000000L;
ry.odd = *rlen;
asm volatile(
" diag %[rx],%[ry],0x8\n"
" ipm %[cc]\n"
" srl %[cc],28\n"
: [cc] "=&d" (cc), [ry] "+&d" (ry.pair)
: [rx] "d" (rx.pair)
: "cc");
if (cc)
*rlen += ry.odd;
else
*rlen = ry.odd;
return ry.even;
}
/*
* __cpcmd has some restrictions over cpcmd
* - __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);
diag_stat_inc(DIAG_STAT_X008);
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)
{
unsigned long flags;
char *lowbuf;
int len;
if (is_vmalloc_or_module_addr(response)) {
lowbuf = kmalloc(rlen, GFP_KERNEL);
if (!lowbuf) {
pr_warn("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);
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