[mirror_ubuntu-artful-kernel.git] / arch / s390 / kernel / cpcmd.c

/*
 *  arch/s390/kernel/cpcmd.c
 *
 *  S390 version
 *    Copyright IBM Corp. 1999,2007
 *    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>
#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) {
			printk(KERN_WARNING
				"cpcmd: could not allocate 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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/s390/kernel/cpcmd.c
	3	*
	4	* S390 version
a004fb0c	5	* Copyright IBM Corp. 1999,2007
1da177e4 LT	6	* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
	7	* Christian Borntraeger (cborntra@de.ibm.com),
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/slab.h>
	13	#include <linux/spinlock.h>
	14	#include <linux/stddef.h>
	15	#include <linux/string.h>
	16	#include <asm/ebcdic.h>
	17	#include <asm/cpcmd.h>
	18	#include <asm/system.h>
bda3563f	19	#include <asm/io.h>
1da177e4 LT	20
1da177e4 LT	21	static DEFINE_SPINLOCK(cpcmd_lock);
6b979de3	22	static char cpcmd_buf[241];
1da177e4	23
a004fb0c HC	24	static int diag8_noresponse(int cmdlen)
	25	{
	26	register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
	27	register unsigned long reg3 asm ("3") = cmdlen;
	28
	29	asm volatile(
	30	#ifndef CONFIG_64BIT
	31	" diag %1,%0,0x8\n"
	32	#else /* CONFIG_64BIT */
	33	" sam31\n"
	34	" diag %1,%0,0x8\n"
	35	" sam64\n"
	36	#endif /* CONFIG_64BIT */
	37	: "+d" (reg3) : "d" (reg2) : "cc");
	38	return reg3;
	39	}
	40
	41	static int diag8_response(int cmdlen, char response, int rlen)
	42	{
	43	register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
	44	register unsigned long reg3 asm ("3") = (addr_t) response;
	45	register unsigned long reg4 asm ("4") = cmdlen \| 0x40000000L;
	46	register unsigned long reg5 asm ("5") = *rlen;
	47
	48	asm volatile(
	49	#ifndef CONFIG_64BIT
	50	" diag %2,%0,0x8\n"
	51	" brc 8,1f\n"
	52	" ar %1,%4\n"
	53	#else /* CONFIG_64BIT */
	54	" sam31\n"
	55	" diag %2,%0,0x8\n"
	56	" sam64\n"
	57	" brc 8,1f\n"
	58	" agr %1,%4\n"
	59	#endif /* CONFIG_64BIT */
	60	"1:\n"
	61	: "+d" (reg4), "+d" (reg5)
	62	: "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
	63	*rlen = reg5;
	64	return reg4;
	65	}
	66
1da177e4	67	/*
740b5706 HC	68	* __cpcmd has some restrictions over cpcmd
	69	* - the response buffer must reside below 2GB (if any)
	70	* - __cpcmd is unlocked and therefore not SMP-safe
1da177e4	71	*/
6b979de3	72	int __cpcmd(const char cmd, char response, int rlen, int *response_code)
1da177e4	73	{
a004fb0c HC	74	int cmdlen;
	75	int rc;
	76	int response_len;
1da177e4	77
1da177e4 LT	78	cmdlen = strlen(cmd);
1da177e4 LT	79	BUG_ON(cmdlen > 240);
6b979de3	80	memcpy(cpcmd_buf, cmd, cmdlen);
1da177e4 LT	81	ASCEBC(cpcmd_buf, cmdlen);
1da177e4 LT	82
a004fb0c	83	if (response) {
1da177e4	84	memset(response, 0, rlen);
a004fb0c HC	85	response_len = rlen;
	86	rc = diag8_response(cmdlen, response, &rlen);
	87	EBCASC(response, response_len);
1da177e4	88	} else {
a004fb0c	89	rc = diag8_noresponse(cmdlen);
1da177e4	90	}
a004fb0c HC	91	if (response_code)
	92	*response_code = rc;
	93	return rlen;
1da177e4	94	}
1da177e4 LT	95	EXPORT_SYMBOL(__cpcmd);
1da177e4 LT	96
6b979de3	97	int cpcmd(const char cmd, char response, int rlen, int *response_code)
1da177e4 LT	98	{
1da177e4 LT	99	char *lowbuf;
6b979de3	100	int len;
740b5706	101	unsigned long flags;
6b979de3	102
bda3563f CB	103	if ((virt_to_phys(response) != (unsigned long) response) \|\|
bda3563f CB	104	(((unsigned long)response + rlen) >> 31)) {
1da177e4 LT	105	lowbuf = kmalloc(rlen, GFP_KERNEL \| GFP_DMA);
	106	if (!lowbuf) {
	107	printk(KERN_WARNING
	108	"cpcmd: could not allocate response buffer\n");
6b979de3	109	return -ENOMEM;
1da177e4	110	}
740b5706	111	spin_lock_irqsave(&cpcmd_lock, flags);
6b979de3	112	len = __cpcmd(cmd, lowbuf, rlen, response_code);
740b5706	113	spin_unlock_irqrestore(&cpcmd_lock, flags);
1da177e4 LT	114	memcpy(response, lowbuf, rlen);
1da177e4 LT	115	kfree(lowbuf);
bda3563f CB	116	} else {
	117	spin_lock_irqsave(&cpcmd_lock, flags);
	118	len = __cpcmd(cmd, response, rlen, response_code);
	119	spin_unlock_irqrestore(&cpcmd_lock, flags);
1da177e4	120	}
6b979de3	121	return len;
1da177e4	122	}
1da177e4	123	EXPORT_SYMBOL(cpcmd);