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Commit 9c203239 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390: calculate loops_per_jiffies with fp instructions 



Implement calculation of loops_per_jiffies with fp instructions which
are available on all 64 bit machines.
To save and restore floating point register context use the new vx support
functions.

Reviewed-by: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent a086171a

arch/s390/kernel/sysinfo.c

+21 −17
Original line number Diff line number Diff line
@@ -16,11 +16,7 @@ 
#include <asm/sysinfo.h>

#include <asm/cpcmd.h>

#include <asm/topology.h>



/* Sigh, math-emu. Don't ask. */

#include <asm/sfp-util.h>

#include <math-emu/soft-fp.h>

#include <math-emu/single.h>

#include <asm/fpu/api.h>



int topology_max_mnest;
@@ -414,10 +410,8 @@ subsys_initcall(create_proc_service_level); 
void s390_adjust_jiffies(void)

{

	struct sysinfo_1_2_2 *info;

	const unsigned int fmil = 0x4b189680;	/* 1e7 as 32-bit float. */

	FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);

	FP_DECL_EX;

	unsigned int capability;

	unsigned long capability;

	struct kernel_fpu fpu;



	info = (void *) get_zeroed_page(GFP_KERNEL);

	if (!info)
@@ -433,15 +427,25 @@ void s390_adjust_jiffies(void) 
		 * higher cpu capacity. Bogomips are the other way round.

		 * To get to a halfway suitable number we divide 1e7

		 * by the cpu capability number. Yes, that means a floating

		 * point division .. math-emu here we come :-)

		 * point division ..

		 */

		FP_UNPACK_SP(SA, &fmil);

		if ((info->capability >> 23) == 0)

			FP_FROM_INT_S(SB, (long) info->capability, 64, long);

		else

			FP_UNPACK_SP(SB, &info->capability);

		FP_DIV_S(SR, SA, SB);

		FP_TO_INT_S(capability, SR, 32, 0);

		kernel_fpu_begin(&fpu, KERNEL_FPR);

		asm volatile(

			"	sfpc	%3\n"

			"	l	%0,%1\n"

			"	tmlh	%0,0xff80\n"

			"	jnz	0f\n"

			"	cefbr	%%f2,%0\n"

			"	j	1f\n"

			"0:	le	%%f2,%1\n"

			"1:	cefbr	%%f0,%2\n"

			"	debr	%%f0,%%f2\n"

			"	cgebr	%0,5,%%f0\n"

			: "=&d" (capability)

			: "Q" (info->capability), "d" (10000000), "d" (0)

			: "cc"

			);

		kernel_fpu_end(&fpu);

	} else

		/*

		 * Really old machine without stsi block for basic