[mirror_ubuntu-artful-kernel.git] / 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/diag.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);

	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)
{
	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_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);
Commit	Line	Data
1da177e4	1	/*
1da177e4	2	* S390 version
a53c8fab	3	* Copyright IBM Corp. 1999, 2007
1da177e4 LT	4	* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
	5	* Christian Borntraeger (cborntra@de.ibm.com),
	6	*/
	7
2f526e5a CB	8	#define KMSG_COMPONENT "cpcmd"
	9	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
	10
1da177e4 LT	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/spinlock.h>
	15	#include <linux/stddef.h>
	16	#include <linux/string.h>
1ec2772e	17	#include <asm/diag.h>
1da177e4 LT	18	#include <asm/ebcdic.h>
1da177e4 LT	19	#include <asm/cpcmd.h>
bda3563f	20	#include <asm/io.h>
1da177e4 LT	21
1da177e4 LT	22	static DEFINE_SPINLOCK(cpcmd_lock);
6b979de3	23	static char cpcmd_buf[241];
1da177e4	24
a004fb0c HC	25	static int diag8_noresponse(int cmdlen)
	26	{
	27	register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
	28	register unsigned long reg3 asm ("3") = cmdlen;
	29
	30	asm volatile(
a004fb0c HC	31	" sam31\n"
	32	" diag %1,%0,0x8\n"
	33	" sam64\n"
a004fb0c HC	34	: "+d" (reg3) : "d" (reg2) : "cc");
	35	return reg3;
	36	}
	37
	38	static int diag8_response(int cmdlen, char response, int rlen)
	39	{
	40	register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
	41	register unsigned long reg3 asm ("3") = (addr_t) response;
	42	register unsigned long reg4 asm ("4") = cmdlen \| 0x40000000L;
	43	register unsigned long reg5 asm ("5") = *rlen;
	44
	45	asm volatile(
a004fb0c HC	46	" sam31\n"
	47	" diag %2,%0,0x8\n"
	48	" sam64\n"
	49	" brc 8,1f\n"
	50	" agr %1,%4\n"
a004fb0c HC	51	"1:\n"
	52	: "+d" (reg4), "+d" (reg5)
	53	: "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
	54	*rlen = reg5;
	55	return reg4;
	56	}
	57
1da177e4	58	/*
740b5706 HC	59	* __cpcmd has some restrictions over cpcmd
	60	* - the response buffer must reside below 2GB (if any)
	61	* - __cpcmd is unlocked and therefore not SMP-safe
1da177e4	62	*/
6b979de3	63	int __cpcmd(const char cmd, char response, int rlen, int *response_code)
1da177e4	64	{
a004fb0c HC	65	int cmdlen;
	66	int rc;
	67	int response_len;
1da177e4	68
1da177e4 LT	69	cmdlen = strlen(cmd);
1da177e4 LT	70	BUG_ON(cmdlen > 240);
6b979de3	71	memcpy(cpcmd_buf, cmd, cmdlen);
1da177e4 LT	72	ASCEBC(cpcmd_buf, cmdlen);
1da177e4 LT	73
1ec2772e	74	diag_stat_inc(DIAG_STAT_X008);
a004fb0c	75	if (response) {
1da177e4	76	memset(response, 0, rlen);
a004fb0c HC	77	response_len = rlen;
	78	rc = diag8_response(cmdlen, response, &rlen);
	79	EBCASC(response, response_len);
1da177e4	80	} else {
a004fb0c	81	rc = diag8_noresponse(cmdlen);
1da177e4	82	}
a004fb0c HC	83	if (response_code)
	84	*response_code = rc;
	85	return rlen;
1da177e4	86	}
1da177e4 LT	87	EXPORT_SYMBOL(__cpcmd);
1da177e4 LT	88
6b979de3	89	int cpcmd(const char cmd, char response, int rlen, int *response_code)
1da177e4 LT	90	{
1da177e4 LT	91	char *lowbuf;
6b979de3	92	int len;
740b5706	93	unsigned long flags;
6b979de3	94
bda3563f CB	95	if ((virt_to_phys(response) != (unsigned long) response) \|\|
bda3563f CB	96	(((unsigned long)response + rlen) >> 31)) {
1da177e4 LT	97	lowbuf = kmalloc(rlen, GFP_KERNEL \| GFP_DMA);
1da177e4 LT	98	if (!lowbuf) {
baebc70a	99	pr_warn("The cpcmd kernel function failed to allocate a response buffer\n");
6b979de3	100	return -ENOMEM;
1da177e4	101	}
740b5706	102	spin_lock_irqsave(&cpcmd_lock, flags);
6b979de3	103	len = __cpcmd(cmd, lowbuf, rlen, response_code);
740b5706	104	spin_unlock_irqrestore(&cpcmd_lock, flags);
1da177e4 LT	105	memcpy(response, lowbuf, rlen);
1da177e4 LT	106	kfree(lowbuf);
bda3563f CB	107	} else {
	108	spin_lock_irqsave(&cpcmd_lock, flags);
	109	len = __cpcmd(cmd, response, rlen, response_code);
	110	spin_unlock_irqrestore(&cpcmd_lock, flags);
1da177e4	111	}
6b979de3	112	return len;
1da177e4	113	}
1da177e4	114	EXPORT_SYMBOL(cpcmd);