From d9f7a745d55527d0d41684b22506a86c4381f7f1 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 28 Sep 2006 16:55:39 +0200 Subject: [S390] __div64_32 for 31 bit. The clocksource infrastructure introduced with commit ad596171ed635c51a9eef829187af100cbf8dcf7 broke 31 bit s390. The reason is that the do_div() primitive for 31 bit always had a restriction: it could only divide an unsigned 64 bit integer by an unsigned 31 bit integer. The clocksource code now uses do_div() with a base value that has the most significant bit set. The result is that clock->cycle_interval has a funny value which causes the linux time to jump around like mad. The solution is "obvious": implement a proper __div64_32 function for 31 bit s390. Signed-off-by: Martin Schwidefsky --- include/asm-s390/div64.h | 48 ------------------------------------------------ 1 file changed, 48 deletions(-) (limited to 'include/asm-s390') diff --git a/include/asm-s390/div64.h b/include/asm-s390/div64.h index af098dc3cf59..6cd978cefb28 100644 --- a/include/asm-s390/div64.h +++ b/include/asm-s390/div64.h @@ -1,49 +1 @@ -#ifndef __S390_DIV64 -#define __S390_DIV64 - -#ifndef __s390x__ - -/* for do_div "base" needs to be smaller than 2^31-1 */ -#define do_div(n, base) ({ \ - unsigned long long __n = (n); \ - unsigned long __r; \ - \ - asm (" slr 0,0\n" \ - " l 1,%1\n" \ - " srdl 0,1\n" \ - " dr 0,%2\n" \ - " alr 1,1\n" \ - " alr 0,0\n" \ - " lhi 2,1\n" \ - " n 2,%1\n" \ - " alr 0,2\n" \ - " clr 0,%2\n" \ - " jl 0f\n" \ - " slr 0,%2\n" \ - " ahi 1,1\n" \ - "0: st 1,%1\n" \ - " l 1,4+%1\n" \ - " srdl 0,1\n" \ - " dr 0,%2\n" \ - " alr 1,1\n" \ - " alr 0,0\n" \ - " lhi 2,1\n" \ - " n 2,4+%1\n" \ - " alr 0,2\n" \ - " clr 0,%2\n" \ - " jl 1f\n" \ - " slr 0,%2\n" \ - " ahi 1,1\n" \ - "1: st 1,4+%1\n" \ - " lr %0,0" \ - : "=d" (__r), "=m" (__n) \ - : "d" (base), "m" (__n) : "0", "1", "2", "cc" ); \ - (n) = (__n); \ - __r; \ -}) - -#else /* __s390x__ */ #include -#endif /* __s390x__ */ - -#endif -- cgit v1.2.2