Commit 0a9d947f authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
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s390/cpcmd: use register pair instead of register asm 



Remove register asm usage from diag8_noresponse() since it wasn't
needed at all. There is no requirement for even/odd register pairs for
diag 0x8.

For diag_response() use register pairs to fulfill the rx+1 and ry+1
requirements as required if a response buffer is specified. Also
change the inline asm to return the condition code of the diagnose
instruction and do the conditional handling of response length
calculation in C.

Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 25130c1a

arch/s390/kernel/cpcmd.c

+22 −20
Original line number Diff line number Diff line
@@ -26,33 +26,35 @@ 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(

		"	diag	%1,%0,0x8\n"

		: "+d" (reg3) : "d" (reg2) : "cc");

	return reg3;

		"	diag	%[rx],%[ry],0x8\n"

		: [ry] "+&d" (cmdlen)

		: [rx] "d" ((addr_t) cpcmd_buf)

		: "cc");

	return cmdlen;

}



static int diag8_response(int cmdlen, char *response, int *rlen)

{

	unsigned long _cmdlen = cmdlen | 0x40000000L;

	unsigned long _rlen = *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;

	register unsigned long reg5 asm ("5") = _rlen;

	union register_pair rx, ry;

	int cc;



	rx.even = (addr_t) cpcmd_buf;

	rx.odd	= (addr_t) response;

	ry.even = cmdlen | 0x40000000L;

	ry.odd	= *rlen;

	asm volatile(

		"	diag	%2,%0,0x8\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;

		"	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;

}



/*