linux-dev/arch/s390/include/asm/timex.h, branch linus/master

s390: define get_cycles macro for arch-override

2022-05-13T21:59:23Z

S390x defines a get_cycles() function, but it does not do the usual `#define get_cycles get_cycles` dance, making it impossible for generic code to see if an arch-specific function was defined. While the get_cycles() ifdef is not currently used, the following timekeeping patch in this series will depend on the macro existing (or not existing) when defining random_get_entropy(). Cc: Thomas Gleixner Cc: Arnd Bergmann Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Acked-by: Heiko Carstens Signed-off-by: Jason A. Donenfeld

s390: convert ".insn" encoding to instruction names

2022-03-10T14:58:17Z

With z10 as minimum supported machine generation many ".insn" encodings could be now converted to instruction names. There are couple of exceptions - stfle is used from the als code built for z900 and cannot be converted - few ".insn" directives encode unsupported instruction formats The generated code is identical before/after this change. Acked-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: raise minimum supported machine generation to z10

2022-03-10T14:58:17Z

Machine generations up to z9 (released in May 2006) have been officially out of service for several years now (z9 end of service - January 31, 2019). No distributions build kernels supporting those old machine generations anymore, except Debian, which seems to pick the oldest supported generation. The team supporting Debian on s390 has been notified about the change. Raising minimum supported machine generation to z10 helps to reduce maintenance cost and effectively remove code, which is not getting enough testing coverage due to lack of older hardware and distributions support. Besides that this unblocks some optimization opportunities and allows to use wider instruction set in asm files for future features implementation. Due to this change spectre mitigation and usercopy implementations could be drastically simplified and many newer instructions could be converted from ".insn" encoding to instruction names. Acked-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/timex: get rid of register asm

2021-06-28T09:18:28Z

Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/time,idle: get rid of unsigned long long

2021-03-08T09:46:27Z

Get rid of unsigned long long, and use unsigned long instead everywhere. The usage of unsigned long long is a leftover from 31 bit kernel support. Signed-off-by: Heiko Carstens

s390/time: remove get_tod_clock_ext()

2021-02-13T16:17:55Z

Remove get_tod_clock_ext() and the STORE_CLOCK_EXT_SIZE define. This enforces all users of the existing low level functions to use a union tod_clock. This way there is now a compile time check for the correct time and therefore also if the size of the argument matches what will be written to by the STORE CLOCK EXTENDED instruction. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/time: convert tod_clock_base to union

2021-02-13T16:17:54Z

Convert tod_clock_base to union tod_clock. This simplifies quite a bit of code and also fixes a bug in read_persistent_clock64(); void read_persistent_clock64(struct timespec64 *ts) { __u64 delta; delta = initial_leap_seconds + TOD_UNIX_EPOCH; get_tod_clock_ext(clk); *(__u64 *) &clk[1] -= delta; if (*(__u64 *) &clk[1] > delta) clk[0]--; ext_to_timespec64(clk, ts); } Assume &clk[1] == 3 and delta == 2; then after the substraction the if condition becomes true and the epoch part of the clock is decremented by one because of an assumed overflow, even though there is none. Fix this by using 128 bit arithmetics and let the compiler do the right thing: void read_persistent_clock64(struct timespec64 *ts) { union tod_clock clk; u64 delta; delta = initial_leap_seconds + TOD_UNIX_EPOCH; store_tod_clock_ext(&clk); clk.eitod -= delta; ext_to_timespec64(&clk, ts); } Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/time: introduce new store_tod_clock_ext()

2021-02-13T16:17:54Z

Introduce new store_tod_clock_ext() function, which is the same like store_tod_clock_ext_cc() except that it doesn't return a condition code. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/time: rename store_tod_clock_ext() and use union tod_clock

2021-02-13T16:17:54Z

Rename store_tod_clock_ext() to store_tod_clock_ext_cc() to reflect that it returns a condition code and also use union tod_clock as parameter. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/time: introduce union tod_clock

2021-02-13T16:17:54Z

Introduce union tod_clock which is supposed to be used to decode and access various fields of the result of STORE CLOCK EXTENDED. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik