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authorHeiko Carstens <heiko.carstens@de.ibm.com>2015-07-01 13:19:19 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2016-06-15 16:37:10 +0200
commit9c203239c5970354536acb3c01000e925bee0270 (patch)
tree664a55151ca9f5f53f3e517c5843edfc4486db8c /arch
parenta086171ad88685f265b0e42894fcdefa3919cdb2 (diff)
downloadlinux-9c203239c5970354536acb3c01000e925bee0270.tar.bz2
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: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/kernel/sysinfo.c38
1 files changed, 21 insertions, 17 deletions
diff --git a/arch/s390/kernel/sysinfo.c b/arch/s390/kernel/sysinfo.c
index f7dba3887a54..96d81502e599 100644
--- a/arch/s390/kernel/sysinfo.c
+++ b/arch/s390/kernel/sysinfo.c
@@ -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