linux-dev/arch/s390/kernel/Makefile, branch master

Merge tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2022-10-10T19:00:45Z

Pull Kbuild updates from Masahiro Yamada: - Remove potentially incomplete targets when Kbuid is interrupted by SIGINT etc in case GNU Make may miss to do that when stderr is piped to another program. - Rewrite the single target build so it works more correctly. - Fix rpm-pkg builds with V=1. - List top-level subdirectories in ./Kbuild. - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms. - Avoid two different modules in lib/zstd/ having shared code, which potentially causes building the common code as build-in and modular back-and-forth. - Unify two modpost invocations to optimize the build process. - Remove head-y syntax in favor of linker scripts for placing particular sections in the head of vmlinux. - Bump the minimal GNU Make version to 3.82. - Clean up misc Makefiles and scripts. * tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits) docs: bump minimal GNU Make version to 3.82 ia64: simplify esi object addition in Makefile Revert "kbuild: Check if linker supports the -X option" kbuild: rebuild .vmlinux.export.o when its prerequisite is updated kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o zstd: Fixing mixed module-builtin objects kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols kallsyms: take the input file instead of reading stdin kallsyms: drop duplicated ignore patterns from kallsyms.c kbuild: reuse mksysmap output for kallsyms mksysmap: update comment about __crc_* kbuild: remove head-y syntax kbuild: use obj-y instead extra-y for objects placed at the head kbuild: hide error checker logs for V=1 builds kbuild: re-run modpost when it is updated kbuild: unify two modpost invocations kbuild: move vmlinux.o rule to the top Makefile kbuild: move .vmlinux.objs rule to Makefile.modpost kbuild: list sub-directories in ./Kbuild Makefile.compiler: replace cc-ifversion with compiler-specific macros ...

kbuild: use obj-y instead extra-y for objects placed at the head

2022-10-02T09:04:05Z

The objects placed at the head of vmlinux need special treatments: - arch/$(SRCARCH)/Makefile adds them to head-y in order to place them before other archives in the linker command line. - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of obj-y to avoid them going into built-in.a. This commit gets rid of the latter. Create vmlinux.a to collect all the objects that are unconditionally linked to vmlinux. The objects listed in head-y are moved to the head of vmlinux.a by using 'ar m'. With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y for builtin objects. There is no *.o that is directly linked to vmlinux. Drop unneeded code in scripts/clang-tools/gen_compile_commands.py. $(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested by Nathan Chancellor [1]. [1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/ Signed-off-by: Masahiro Yamada Tested-by: Nick Desaulniers Reviewed-by: Nicolas Schier

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/smp: rework absolute lowcore access

2022-09-14T14:46:00Z

Temporary unsetting of the prefix page in memcpy_absolute() routine poses a risk of executing code path with unexpectedly disabled prefix page. This rework avoids the prefix page uninstalling and disabling of normal and machine check interrupts when accessing the absolute zero memory. Although memcpy_absolute() routine can access the whole memory, it is only used to update the absolute zero lowcore. This rework therefore introduces a new mechanism for the absolute zero lowcore access and scraps memcpy_absolute() routine for good. Instead, an area is reserved in the virtual memory that is used for the absolute lowcore access only. That area holds an array of 8KB virtual mappings - one per CPU. Whenever a CPU is brought online, the corresponding item is mapped to the real address of the previously installed prefix page. The absolute zero lowcore access works like this: a CPU calls the new primitive get_abs_lowcore() to obtain its 8KB mapping as a pointer to the struct lowcore. Virtual address references to that pointer get translated to the real addresses of the prefix page, which in turn gets swapped with the absolute zero memory addresses due to prefixing. Once the pointer is not needed it must be released with put_abs_lowcore() primitive: struct lowcore *abs_lc; unsigned long flags; abs_lc = get_abs_lowcore(&flags); abs_lc->... = ...; put_abs_lowcore(abs_lc, flags); To ensure the described mechanism works large segment- and region- table entries must be avoided for the 8KB mappings. Failure to do so results in usage of Region-Frame Absolute Address (RFAA) or Segment-Frame Absolute Address (SFAA) large page fields. In that case absolute addresses would be used to address the prefix page instead of the real ones and the prefixing would get bypassed. Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

Revert "s390/smp: rework absolute lowcore access"

2022-08-06T07:24:07Z

This reverts commit 7d06fed77b7d8fc9f6cc41b4e3f2823d32532ad8. This introduced vmem_mutex locking from vmem_map_4k_page() function called from smp_reinit_ipl_cpu() with interrupts disabled. While it is a pre-SMP early initcall no other CPUs running in parallel nor other code taking vmem_mutex on this boot stage - it still needs to be fixed. Signed-off-by: Alexander Gordeev

s390/smp: rework absolute lowcore access

2022-07-28T16:05:23Z

s390/cpufeature: rework to allow more than only hwcap bits

2022-07-19T14:18:49Z

Rework cpufeature implementation to allow for various cpu feature indications, which is not only limited to hwcap bits. This is achieved by adding a sequential list of cpu feature numbers, where each of them is mapped to an entry which indicates what this number is about. Each entry contains a type member, which indicates what feature name space to look into (e.g. hwcap, or cpu facility). If wanted this allows also to automatically load modules only in e.g. z/VM configurations. Signed-off-by: Heiko Carstens Signed-off-by: Steffen Eiden Reviewed-by: Claudio Imbrenda Reviewed-by: Hendrik Brueckner Link: https://lore.kernel.org/r/20220713125644.16121-2-seiden@linux.ibm.com Signed-off-by: Alexander Gordeev

s390: simplify early program check handler

2022-05-25T09:46:02Z

Due to historic reasons the base program check handler calls a configurable function. Given that there is only the early program check handler left, simplify the code by directly calling that function. The only other user was removed with commit d485235b0054 ("s390: assume diag308 set always works"). Also rename all functions and the asm file to reflect this. Reviewed-by: Sven Schnelle Signed-off-by: Heiko Carstens

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/kprobes: Avoid additional kprobe in kretprobe handling

2022-03-10T14:58:17Z

So far, s390 registered a krobe on __kretprobe_trampoline which is called everytime a kretprobe fires. This kprobe would then determine the correct return address and adjust the psw accordingly, such that the kretprobe would branch to the appropriate address after completion. Some other archs handle kretprobes without such an additional kprobe. This approach is adopted to s390 with this patch. Furthermore, the __kretprobe_trampoline now uses an assembler function to correctly gather the register and psw content to be passed to the registered kretprobe handler as struct pt_regs. After completion, the register content and the psw are set based on the contents of said pt_regs struct. Note that a change to the psw address in struct pt_regs will not have an impact, as the probe will still return to the original return address of the probed function. The return address is now recovered by using the appropriate function arch_kretprobe_fixup_return. The no longer needed kprobe is removed. Reviewed-by: Vasily Gorbik Signed-off-by: Tobias Huschle Signed-off-by: Vasily Gorbik