From 31ee4b2f40994e8b21691f85cdd4052551a789b7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 5 Feb 2007 21:18:31 +0100 Subject: [PATCH] [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 --- arch/s390/Kconfig | 4 - arch/s390/kernel/setup.c | 1 + arch/s390/lib/Makefile | 2 +- arch/s390/lib/qrnnd.S | 77 +++++++++++++++++++ arch/s390/math-emu/Makefile | 2 +- arch/s390/math-emu/math.c | 2 +- arch/s390/math-emu/qrnnd.S | 77 ------------------- drivers/s390/Makefile | 2 + drivers/s390/sysinfo.c | 63 ++++++++++++++- include/asm-s390/processor.h | 1 + .../math-emu => include/asm-s390}/sfp-util.h | 6 +- 11 files changed, 149 insertions(+), 88 deletions(-) create mode 100644 arch/s390/lib/qrnnd.S delete mode 100644 arch/s390/math-emu/qrnnd.S rename {arch/s390/math-emu => include/asm-s390}/sfp-util.h (91%) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 5c7e981c115b..eaed402ad346 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -34,10 +34,6 @@ config GENERIC_HWEIGHT 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 2569aafcc543..2fa866f6f711 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -938,6 +938,7 @@ static int show_cpuinfo(struct seq_file *m, void *v) 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 b5f94cf3bde8..7a44fed21b35 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 000000000000..eb1df632e749 --- /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 c10df144f2ab..73b3e72efc46 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 6b9aec5a2c18..3ee78ccb617d 100644 --- a/arch/s390/math-emu/math.c +++ b/arch/s390/math-emu/math.c @@ -15,7 +15,7 @@ #include #include -#include "sfp-util.h" +#include #include #include #include diff --git a/arch/s390/math-emu/qrnnd.S b/arch/s390/math-emu/qrnnd.S deleted file mode 100644 index b01c2b648e22..000000000000 --- 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 9803c9352d78..5a888704a8d0 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 1e788e815ce7..090743d2f914 100644 --- a/drivers/s390/sysinfo.c +++ b/drivers/s390/sysinfo.c @@ -9,8 +9,14 @@ #include #include #include +#include #include +/* Sigh, math-emu. Don't ask. */ +#include +#include +#include + struct sysinfo_1_1_1 { char reserved_0[32]; char manufacturer[16]; @@ -198,7 +204,7 @@ static int stsi_1_2_2(struct sysinfo_1_2_2 *info, char *page, int len) * 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 @@ static __init int create_proc_sysinfo(void) __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 5af853576cbd..cf71c5449240 100644 --- a/include/asm-s390/processor.h +++ b/include/asm-s390/processor.h @@ -50,6 +50,7 @@ struct cpuinfo_S390 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 91% rename from arch/s390/math-emu/sfp-util.h rename to include/asm-s390/sfp-util.h index 5b6ca4570ea4..8cabcd23d976 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 -- 2.20.1