// 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 pr_fmt(fmt) "cpcmd: " 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>#include <asm/asm.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"		CC_IPM(cc)		: CC_OUT(cc, cc), [ry] "+d" (ry.pair)		: [rx] "d" (rx.pair)		: CC_CLOBBER);	if (CC_TRANSFORM(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);