[linux-2.6-block.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),
 */

#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/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) {
			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);
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
2f526e5a CB	10	#define KMSG_COMPONENT "cpcmd"
	11	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	12
1da177e4 LT	13	#include <linux/kernel.h>
	14	#include <linux/module.h>
	15	#include <linux/slab.h>
	16	#include <linux/spinlock.h>
	17	#include <linux/stddef.h>
	18	#include <linux/string.h>
	19	#include <asm/ebcdic.h>
	20	#include <asm/cpcmd.h>
	21	#include <asm/system.h>
bda3563f	22	#include <asm/io.h>
1da177e4 LT	23
1da177e4 LT	24	static DEFINE_SPINLOCK(cpcmd_lock);
6b979de3	25	static char cpcmd_buf[241];
1da177e4	26
a004fb0c HC	27	static int diag8_noresponse(int cmdlen)
	28	{
	29	register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
	30	register unsigned long reg3 asm ("3") = cmdlen;
	31
	32	asm volatile(
	33	#ifndef CONFIG_64BIT
	34	" diag %1,%0,0x8\n"
	35	#else /* CONFIG_64BIT */
	36	" sam31\n"
	37	" diag %1,%0,0x8\n"
	38	" sam64\n"
	39	#endif /* CONFIG_64BIT */
	40	: "+d" (reg3) : "d" (reg2) : "cc");
	41	return reg3;
	42	}
	43
	44	static int diag8_response(int cmdlen, char response, int rlen)
	45	{
	46	register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
	47	register unsigned long reg3 asm ("3") = (addr_t) response;
	48	register unsigned long reg4 asm ("4") = cmdlen \| 0x40000000L;
	49	register unsigned long reg5 asm ("5") = *rlen;
	50
	51	asm volatile(
	52	#ifndef CONFIG_64BIT
	53	" diag %2,%0,0x8\n"
	54	" brc 8,1f\n"
	55	" ar %1,%4\n"
	56	#else /* CONFIG_64BIT */
	57	" sam31\n"
	58	" diag %2,%0,0x8\n"
	59	" sam64\n"
	60	" brc 8,1f\n"
	61	" agr %1,%4\n"
	62	#endif /* CONFIG_64BIT */
	63	"1:\n"
	64	: "+d" (reg4), "+d" (reg5)
	65	: "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
	66	*rlen = reg5;
	67	return reg4;
	68	}
	69
1da177e4	70	/*
740b5706 HC	71	* __cpcmd has some restrictions over cpcmd
	72	* - the response buffer must reside below 2GB (if any)
	73	* - __cpcmd is unlocked and therefore not SMP-safe
1da177e4	74	*/
6b979de3	75	int __cpcmd(const char cmd, char response, int rlen, int *response_code)
1da177e4	76	{
a004fb0c HC	77	int cmdlen;
	78	int rc;
	79	int response_len;
1da177e4	80
1da177e4 LT	81	cmdlen = strlen(cmd);
1da177e4 LT	82	BUG_ON(cmdlen > 240);
6b979de3	83	memcpy(cpcmd_buf, cmd, cmdlen);
1da177e4 LT	84	ASCEBC(cpcmd_buf, cmdlen);
1da177e4 LT	85
a004fb0c	86	if (response) {
1da177e4	87	memset(response, 0, rlen);
a004fb0c HC	88	response_len = rlen;
	89	rc = diag8_response(cmdlen, response, &rlen);
	90	EBCASC(response, response_len);
1da177e4	91	} else {
a004fb0c	92	rc = diag8_noresponse(cmdlen);
1da177e4	93	}
a004fb0c HC	94	if (response_code)
	95	*response_code = rc;
	96	return rlen;
1da177e4	97	}
1da177e4 LT	98	EXPORT_SYMBOL(__cpcmd);
1da177e4 LT	99
6b979de3	100	int cpcmd(const char cmd, char response, int rlen, int *response_code)
1da177e4 LT	101	{
1da177e4 LT	102	char *lowbuf;
6b979de3	103	int len;
740b5706	104	unsigned long flags;
6b979de3	105
bda3563f CB	106	if ((virt_to_phys(response) != (unsigned long) response) \|\|
bda3563f CB	107	(((unsigned long)response + rlen) >> 31)) {
1da177e4 LT	108	lowbuf = kmalloc(rlen, GFP_KERNEL \| GFP_DMA);
1da177e4 LT	109	if (!lowbuf) {
2f526e5a CB	110	pr_warning("The cpcmd kernel function failed to "
2f526e5a CB	111	"allocate a response buffer\n");
6b979de3	112	return -ENOMEM;
1da177e4	113	}
740b5706	114	spin_lock_irqsave(&cpcmd_lock, flags);
6b979de3	115	len = __cpcmd(cmd, lowbuf, rlen, response_code);
740b5706	116	spin_unlock_irqrestore(&cpcmd_lock, flags);
1da177e4 LT	117	memcpy(response, lowbuf, rlen);
1da177e4 LT	118	kfree(lowbuf);
bda3563f CB	119	} else {
	120	spin_lock_irqsave(&cpcmd_lock, flags);
	121	len = __cpcmd(cmd, response, rlen, response_code);
	122	spin_unlock_irqrestore(&cpcmd_lock, flags);
1da177e4	123	}
6b979de3	124	return len;
1da177e4	125	}
1da177e4	126	EXPORT_SYMBOL(cpcmd);