[S390] Calibrate delay and bogomips.
Preset the bogomips number to the cpu capacity value reported by
store system information in SYSIB 1.2.2. This value is constant
for a particular machine model and can be used to determine
relative performance differences between machines.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 5c7e981..eaed402 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -34,10 +34,6 @@
bool
default y
-config GENERIC_CALIBRATE_DELAY
- bool
- default y
-
config GENERIC_TIME
def_bool y
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2569aaf..2fa866f 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -938,6 +938,7 @@
struct cpuinfo_S390 *cpuinfo;
unsigned long n = (unsigned long) v - 1;
+ s390_adjust_jiffies();
preempt_disable();
if (!n) {
seq_printf(m, "vendor_id : IBM/S390\n"
diff --git a/arch/s390/lib/Makefile b/arch/s390/lib/Makefile
index b5f94cf..7a44fed 100644
--- a/arch/s390/lib/Makefile
+++ b/arch/s390/lib/Makefile
@@ -4,7 +4,7 @@
EXTRA_AFLAGS := -traditional
-lib-y += delay.o string.o uaccess_std.o uaccess_pt.o
+lib-y += delay.o string.o uaccess_std.o uaccess_pt.o qrnnd.o
lib-$(CONFIG_32BIT) += div64.o
lib-$(CONFIG_64BIT) += uaccess_mvcos.o
lib-$(CONFIG_SMP) += spinlock.o
diff --git a/arch/s390/lib/qrnnd.S b/arch/s390/lib/qrnnd.S
new file mode 100644
index 0000000..eb1df63
--- /dev/null
+++ b/arch/s390/lib/qrnnd.S
@@ -0,0 +1,77 @@
+# S/390 __udiv_qrnnd
+
+# r2 : &__r
+# r3 : upper half of 64 bit word n
+# r4 : lower half of 64 bit word n
+# r5 : divisor d
+# the reminder r of the division is to be stored to &__r and
+# the quotient q is to be returned
+
+ .text
+ .globl __udiv_qrnnd
+__udiv_qrnnd:
+ st %r2,24(%r15) # store pointer to reminder for later
+ lr %r0,%r3 # reload n
+ lr %r1,%r4
+ ltr %r2,%r5 # reload and test divisor
+ jp 5f
+ # divisor >= 0x80000000
+ srdl %r0,2 # n/4
+ srl %r2,1 # d/2
+ slr %r1,%r2 # special case if last bit of d is set
+ brc 3,0f # (n/4) div (n/2) can overflow by 1
+ ahi %r0,-1 # trick: subtract n/2, then divide
+0: dr %r0,%r2 # signed division
+ ahi %r1,1 # trick part 2: add 1 to the quotient
+ # now (n >> 2) = (d >> 1) * %r1 + %r0
+ lhi %r3,1
+ nr %r3,%r1 # test last bit of q
+ jz 1f
+ alr %r0,%r2 # add (d>>1) to r
+1: srl %r1,1 # q >>= 1
+ # now (n >> 2) = (d&-2) * %r1 + %r0
+ lhi %r3,1
+ nr %r3,%r5 # test last bit of d
+ jz 2f
+ slr %r0,%r1 # r -= q
+ brc 3,2f # borrow ?
+ alr %r0,%r5 # r += d
+ ahi %r1,-1
+2: # now (n >> 2) = d * %r1 + %r0
+ alr %r1,%r1 # q <<= 1
+ alr %r0,%r0 # r <<= 1
+ brc 12,3f # overflow on r ?
+ slr %r0,%r5 # r -= d
+ ahi %r1,1 # q += 1
+3: lhi %r3,2
+ nr %r3,%r4 # test next to last bit of n
+ jz 4f
+ ahi %r0,1 # r += 1
+4: clr %r0,%r5 # r >= d ?
+ jl 6f
+ slr %r0,%r5 # r -= d
+ ahi %r1,1 # q += 1
+ # now (n >> 1) = d * %r1 + %r0
+ j 6f
+5: # divisor < 0x80000000
+ srdl %r0,1
+ dr %r0,%r2 # signed division
+ # now (n >> 1) = d * %r1 + %r0
+6: alr %r1,%r1 # q <<= 1
+ alr %r0,%r0 # r <<= 1
+ brc 12,7f # overflow on r ?
+ slr %r0,%r5 # r -= d
+ ahi %r1,1 # q += 1
+7: lhi %r3,1
+ nr %r3,%r4 # isolate last bit of n
+ alr %r0,%r3 # r += (n & 1)
+ clr %r0,%r5 # r >= d ?
+ jl 8f
+ slr %r0,%r5 # r -= d
+ ahi %r1,1 # q += 1
+8: # now n = d * %r1 + %r0
+ l %r2,24(%r15)
+ st %r0,0(%r2)
+ lr %r2,%r1
+ br %r14
+ .end __udiv_qrnnd
diff --git a/arch/s390/math-emu/Makefile b/arch/s390/math-emu/Makefile
index c10df14..73b3e72 100644
--- a/arch/s390/math-emu/Makefile
+++ b/arch/s390/math-emu/Makefile
@@ -2,7 +2,7 @@
# Makefile for the FPU instruction emulation.
#
-obj-$(CONFIG_MATHEMU) := math.o qrnnd.o
+obj-$(CONFIG_MATHEMU) := math.o
EXTRA_CFLAGS := -I$(src) -Iinclude/math-emu -w
EXTRA_AFLAGS := -traditional
diff --git a/arch/s390/math-emu/math.c b/arch/s390/math-emu/math.c
index 6b9aec5..3ee78cc 100644
--- a/arch/s390/math-emu/math.c
+++ b/arch/s390/math-emu/math.c
@@ -15,7 +15,7 @@
#include <asm/uaccess.h>
#include <asm/lowcore.h>
-#include "sfp-util.h"
+#include <asm/sfp-util.h>
#include <math-emu/soft-fp.h>
#include <math-emu/single.h>
#include <math-emu/double.h>
diff --git a/arch/s390/math-emu/qrnnd.S b/arch/s390/math-emu/qrnnd.S
deleted file mode 100644
index b01c2b6..0000000
--- a/arch/s390/math-emu/qrnnd.S
+++ /dev/null
@@ -1,77 +0,0 @@
-# S/390 __udiv_qrnnd
-
-# r2 : &__r
-# r3 : upper half of 64 bit word n
-# r4 : lower half of 64 bit word n
-# r5 : divisor d
-# the reminder r of the division is to be stored to &__r and
-# the quotient q is to be returned
-
- .text
- .globl __udiv_qrnnd
-__udiv_qrnnd:
- st %r2,24(%r15) # store pointer to reminder for later
- lr %r0,%r3 # reload n
- lr %r1,%r4
- ltr %r2,%r5 # reload and test divisor
- jp 5f
- # divisor >= 0x80000000
- srdl %r0,2 # n/4
- srl %r2,1 # d/2
- slr %r1,%r2 # special case if last bit of d is set
- brc 3,0f # (n/4) div (n/2) can overflow by 1
- ahi %r0,-1 # trick: subtract n/2, then divide
-0: dr %r0,%r2 # signed division
- ahi %r1,1 # trick part 2: add 1 to the quotient
- # now (n >> 2) = (d >> 1) * %r1 + %r0
- lhi %r3,1
- nr %r3,%r1 # test last bit of q
- jz 1f
- alr %r0,%r2 # add (d>>1) to r
-1: srl %r1,1 # q >>= 1
- # now (n >> 2) = (d&-2) * %r1 + %r0
- lhi %r3,1
- nr %r3,%r5 # test last bit of d
- jz 2f
- slr %r0,%r1 # r -= q
- brc 3,2f # borrow ?
- alr %r0,%r5 # r += d
- ahi %r1,-1
-2: # now (n >> 2) = d * %r1 + %r0
- alr %r1,%r1 # q <<= 1
- alr %r0,%r0 # r <<= 1
- brc 12,3f # overflow on r ?
- slr %r0,%r5 # r -= d
- ahi %r1,1 # q += 1
-3: lhi %r3,2
- nr %r3,%r4 # test next to last bit of n
- jz 4f
- ahi %r0,1 # r += 1
-4: clr %r0,%r5 # r >= d ?
- jl 6f
- slr %r0,%r5 # r -= d
- ahi %r1,1 # q += 1
- # now (n >> 1) = d * %r1 + %r0
- j 6f
-5: # divisor < 0x80000000
- srdl %r0,1
- dr %r0,%r2 # signed division
- # now (n >> 1) = d * %r1 + %r0
-6: alr %r1,%r1 # q <<= 1
- alr %r0,%r0 # r <<= 1
- brc 12,7f # overflow on r ?
- slr %r0,%r5 # r -= d
- ahi %r1,1 # q += 1
-7: lhi %r3,1
- nr %r3,%r4 # isolate last bit of n
- alr %r0,%r3 # r += (n & 1)
- clr %r0,%r5 # r >= d ?
- jl 8f
- slr %r0,%r5 # r -= d
- ahi %r1,1 # q += 1
-8: # now n = d * %r1 + %r0
- l %r2,24(%r15)
- st %r0,0(%r2)
- lr %r2,%r1
- br %r14
- .end __udiv_qrnnd
diff --git a/drivers/s390/Makefile b/drivers/s390/Makefile
index 9803c93..5a88870 100644
--- a/drivers/s390/Makefile
+++ b/drivers/s390/Makefile
@@ -2,6 +2,8 @@
# Makefile for the S/390 specific device drivers
#
+CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w
+
obj-y += s390mach.o sysinfo.o s390_rdev.o
obj-y += cio/ block/ char/ crypto/ net/ scsi/
diff --git a/drivers/s390/sysinfo.c b/drivers/s390/sysinfo.c
index 1e788e8..090743d 100644
--- a/drivers/s390/sysinfo.c
+++ b/drivers/s390/sysinfo.c
@@ -9,8 +9,14 @@
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
+#include <linux/delay.h>
#include <asm/ebcdic.h>
+/* Sigh, math-emu. Don't ask. */
+#include <asm/sfp-util.h>
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+
struct sysinfo_1_1_1 {
char reserved_0[32];
char manufacturer[16];
@@ -198,7 +204,7 @@
* if the higher order 8 bits are not zero. Printing
* a floating point number in the kernel is a no-no,
* always print the number as 32 bit unsigned integer.
- * The user-space needs to know about the stange
+ * The user-space needs to know about the strange
* encoding of the alternate cpu capability.
*/
len += sprintf(page + len, "Capability: %u %u\n",
@@ -351,3 +357,58 @@
__initcall(create_proc_sysinfo);
+/*
+ * CPU capability might have changed. Therefore recalculate loops_per_jiffy.
+ */
+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;
+
+ info = (void *) get_zeroed_page(GFP_KERNEL);
+ if (!info)
+ return;
+
+ if (stsi(info, 1, 2, 2) != -ENOSYS) {
+ /*
+ * Major sigh. The cpu capability encoding is "special".
+ * If the first 9 bits of info->capability are 0 then it
+ * is a 32 bit unsigned integer in the range 0 .. 2^23.
+ * If the first 9 bits are != 0 then it is a 32 bit float.
+ * In addition a lower value indicates a proportionally
+ * 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 :-)
+ */
+ FP_UNPACK_SP(SA, &fmil);
+ if ((info->capability >> 23) == 0)
+ FP_FROM_INT_S(SB, info->capability, 32, int);
+ else
+ FP_UNPACK_SP(SB, &info->capability);
+ FP_DIV_S(SR, SA, SB);
+ FP_TO_INT_S(capability, SR, 32, 0);
+ } else
+ /*
+ * Really old machine without stsi block for basic
+ * cpu information. Report 42.0 bogomips.
+ */
+ capability = 42;
+ loops_per_jiffy = capability * (500000/HZ);
+ free_page((unsigned long) info);
+}
+
+/*
+ * calibrate the delay loop
+ */
+void __init calibrate_delay(void)
+{
+ s390_adjust_jiffies();
+ /* Print the good old Bogomips line .. */
+ printk(KERN_DEBUG "Calibrating delay loop (skipped)... "
+ "%lu.%02lu BogoMIPS preset\n", loops_per_jiffy/(500000/HZ),
+ (loops_per_jiffy/(5000/HZ)) % 100);
+}
diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index 5af8535..cf71c54 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -50,6 +50,7 @@
unsigned long pgtable_cache_sz;
};
+extern void s390_adjust_jiffies(void);
extern void print_cpu_info(struct cpuinfo_S390 *);
/* Lazy FPU handling on uni-processor */
diff --git a/arch/s390/math-emu/sfp-util.h b/include/asm-s390/sfp-util.h
similarity index 90%
rename from arch/s390/math-emu/sfp-util.h
rename to include/asm-s390/sfp-util.h
index 5b6ca45..8cabcd2 100644
--- a/arch/s390/math-emu/sfp-util.h
+++ b/include/asm-s390/sfp-util.h
@@ -52,12 +52,12 @@
})
#define udiv_qrnnd(q, r, n1, n0, d) \
- do { unsigned long __r; \
+ do { unsigned int __r; \
(q) = __udiv_qrnnd (&__r, (n1), (n0), (d)); \
(r) = __r; \
} while (0)
-extern unsigned long __udiv_qrnnd (unsigned long *, unsigned long,
- unsigned long , unsigned long);
+extern unsigned long __udiv_qrnnd (unsigned int *, unsigned int,
+ unsigned int , unsigned int);
#define UDIV_NEEDS_NORMALIZATION 0