kernel/arch/s390/include/asm/lowcore.h, branch linux-6.2.y

s390/pai: Add support for PAI Extension 1 NNPA counters

2022-09-16T16:36:25Z

PMU device driver perf_paiext supports Processor Activity Instrumentation Extension (PAIE1), available with IBM z16: - maps a 512 byte block to lowcore address 0x1508 called PAIE1 control block. - maps a 1024 byte block at PAIE1 control block entry with index 2. - uses control register bit 14 to enable PAIE1 control block lookup. - turn PAIE1 nnpa counting on and off by setting bit 63 in PAIE1 control block entry with index 2. - creates a sample with raw data on each context switch out when at context switch some mapped counters have a value of nonzero. This device driver only supports CPU wide context, no task context is allowed. Support for counting: - one or more counters can be specified using perf stat -e pai_ext/xxx/ where xxx stands for the counter event name. Multiple invocation of this command is possible. The counter names are listed in /sys/devices/pai_ext/events directory. - one special counters can be specified using perf stat -e pai_ext/NNPA_ALL/ which returns the sum of all incremented nnpa counters. - multiple counting events can run in parallel. Support for Sampling: - one event pai_ext/NNPA_ALL/ is reserved for sampling. The event collects data at context switch out and saves them in the ring buffer. - no multiple invocations are possible. The PAIE1 nnpa counter events are system wide. No task context is supported. Therefore some restrictions documented in function paiext_busy() apply. Extend qpaci assembly instruction to query supported memory mapped nnpa counters. It returns the number of counters (no holes allowed in that range). PAIE1 nnpa counter events can not be created when a CPU hot plug add is processed. This means a CPU hot plug add does not get the necessary PAIE1 event to record PAIE1 nnpa counter increments on the newly added CPU. CPU hot plug remove removes the event and terminates the counting of PAIE1 counters immediately. Signed-off-by: Thomas Richter Reviewed-by: Sumanth Korikkar Reviewed-by: Sven Schnelle Signed-off-by: Vasily Gorbik

s390/pai: add support for cryptography counters

2022-05-09T09:50:01Z

PMU device driver perf_pai_crypto supports Processor Activity Instrumentation (PAI), available with IBM z16: - maps a full page to lowcore address 0x1500. - uses CR0 bit 13 to turn PAI crypto counting on and off. - creates a sample with raw data on each context switch out when at context switch some mapped counters have a value of nonzero. This device driver only supports CPU wide context, no task context is allowed. Support for counting: - one or more counters can be specified using perf stat -e pai_crypto/xxx/ where xxx stands for the counter event name. Multiple invocation of this command is possible. The counter names are listed in /sys/devices/pai_crypto/events directory. - one special counters can be specified using perf stat -e pai_crypto/CRYPTO_ALL/ which returns the sum of all incremented crypto counters. - one event pai_crypto/CRYPTO_ALL/ is reserved for sampling. No multiple invocations are possible. The event collects data at context switch out and saves them in the ring buffer. Add qpaci assembly instruction to query supported memory mapped crypto counters. It returns the number of counters (no holes allowed in that range). The PAI crypto counter events are system wide and can not be executed in parallel. Therefore some restrictions documented in function paicrypt_busy apply. In particular event CRYPTO_ALL for sampling must run exclusive. Only counting events can run in parallel. PAI crypto counter events can not be created when a CPU hot plug add is processed. This means a CPU hot plug add does not get the necessary PAI event to record PAI cryptography counter increments on the newly added CPU. CPU hot plug remove removes the event and terminates the counting of PAI counters immediately. Co-developed-by: Sven Schnelle Signed-off-by: Sven Schnelle Reviewed-by: Juergen Christ Signed-off-by: Thomas Richter Link: https://lore.kernel.org/r/20220504062351.2954280-3-tmricht@linux.ibm.com Signed-off-by: Heiko Carstens

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/traps: get rid of magic cast for per code

2022-03-07T23:33:01Z

Add a proper union in lowcore to reflect architecture and get rid of a "magic" cast in order to read the full per code. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/traps: get rid of magic cast for program interruption code

2022-03-07T23:33:01Z

Add a proper union in lowcore to reflect architecture and get rid of a "magic" cast in order to read the full program interruption code. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: add support for BEAR enhancement facility

2021-10-26T13:21:29Z

The Breaking-Event-Address-Register (BEAR) stores the address of the last breaking event instruction. Breaking events are usually instructions that change the program flow - for example branches, and instructions that modify the address in the PSW like lpswe. This is useful for debugging wild branches, because one could easily figure out where the wild branch was originating from. What is problematic is that lpswe is considered a breaking event, and therefore overwrites BEAR on kernel exit. The BEAR enhancement facility adds new instructions that allow to save/restore BEAR and also an lpswey instruction that doesn't cause a breaking event. So we can save BEAR on kernel entry and restore it on exit to user space. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: rename last_break to pgm_last_break

2021-10-26T13:21:28Z

With the upcoming BEAR enhancements last_break isn't really unique, so rename it to pgm_last_break. This way it should be more obvious that this is the last_break value that is written by the hardware when a program check occurs. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/smp: enable DAT before CPU restart callback is called

2021-08-26T18:22:12Z

The restart interrupt is triggered whenever a secondary CPU is brought online, a remote function call dispatched from another CPU or a manual PSW restart is initiated and causes the system to kdump. The handling routine is always called with DAT turned off. It then initializes the stack frame and invokes a callback. The existing callbacks handle DAT as follows: * __do_restart() and __machine_kexec() turn in on upon entry; * __ipl_run(), __reipl_run() and __dump_run() do not turn it right away, but all of them call diag308() - which turns DAT on, but only if kasan is enabled; In addition to the described complexity all callbacks (and the functions they call) should avoid kasan instrumentation while DAT is off. This update enables DAT in the assembler restart handler and relieves any callbacks (which are mostly C functions) from dealing with DAT altogether. There are four types of CPU restart that initialize control registers in different ways: 1. Start of secondary CPU on boot - control registers are inherited from the IPL CPU; 2. Restart of online CPU - control registers of the CPU being restarted are kept; 3. Hotplug of offline CPU - control registers are inherited from the starting CPU; 4. Start of offline CPU triggered by manual PSW restart - the control registers are read from the absolute lowcore and contain the boot time IPL CPU values updated with all follow-up calls of smp_ctl_set_bit() and smp_ctl_clear_bit() routines; In first three cases contents of the control registers is the most recent. In the latter case control registers are good enough to facilitate successful completion of kdump operation. Suggested-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/lowcore: remove superfluous __packed annotations

2021-06-07T15:07:01Z

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

s390: use struct tpi_info in lowcore.h

2021-06-07T15:07:01Z

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