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* Merge tag 's390-6.12-2' of ↵Linus Torvalds2024-09-282-50/+40
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Vasily Gorbik: - Clean up and improve vdso code: use SYM_* macros for function and data annotations, add CFI annotations to fix GDB unwinding, optimize the chacha20 implementation - Add vfio-ap driver feature advertisement for use by libvirt and mdevctl * tag 's390-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/vfio-ap: Driver feature advertisement s390/vdso: Use one large alternative instead of an alternative branch s390/vdso: Use SYM_DATA_START_LOCAL()/SYM_DATA_END() for data objects tools: Add additional SYM_*() stubs to linkage.h s390/vdso: Use macros for annotation of asm functions s390/vdso: Add CFI annotations to __arch_chacha20_blocks_nostack() s390/vdso: Fix comment within __arch_chacha20_blocks_nostack() s390/vdso: Get rid of permutation constants
| * s390/vdso: Use one large alternative instead of an alternative branchHeiko Carstens2024-09-231-19/+16
| | | | | | | | | | | | | | | | | | | | Replace the alternative branch with a larger alternative that contains both paths. That way the two paths are closer together and it is easier to change both paths if the need should arise. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/vdso: Use SYM_DATA_START_LOCAL()/SYM_DATA_END() for data objectsHeiko Carstens2024-09-231-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use SYM_DATA_START_LOCAL()/SYM_DATA_END() in vgetrandom-chacha.S so that the constants end up in an object with correct size: readelf -Ws vgetrandom-chacha.o Num: Value Size Type Bind Vis Ndx Name ... 5: 0000000000000000 32 OBJECT LOCAL DEFAULT 5 chacha20_constants Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/vdso: Use macros for annotation of asm functionsJens Remus2024-09-231-10/+4
| | | | | | | | | | | | | | | | | | | | Use the macros SYM_FUNC_START() and SYM_FUNC_END() to annotate the functions in assembly. Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/vdso: Add CFI annotations to __arch_chacha20_blocks_nostack()Jens Remus2024-09-231-0/+3
| | | | | | | | | | | | | | | | | | | | This allows proper unwinding, for instance when using a debugger such as GDB. Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/vdso: Fix comment within __arch_chacha20_blocks_nostack()Heiko Carstens2024-09-231-4/+4
| | | | | | | | | | | | | | | | | | Fix comment within __arch_chacha20_blocks_nostack() so the comment reflects what the code is doing. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * s390/vdso: Get rid of permutation constantsHeiko Carstens2024-09-231-15/+10
| | | | | | | | | | | | | | | | | | | | The three byte masks for VECTOR PERMUTE are not needed, since the instruction VECTOR SHIFT LEFT DOUBLE BY BYTE can be used to implement the required "rotate left" easily. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
* | [tree-wide] finally take no_llseek outAl Viro2024-09-273-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\<no_llseek\>/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge tag 'asm-generic-6.12' of ↵Linus Torvalds2024-09-261-2/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic updates from Arnd Bergmann: "These are only two small patches, one cleanup for arch/alpha and a preparation patch cleaning up the handling of runtime constants in the linker scripts" * tag 'asm-generic-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: runtime constants: move list of constants to vmlinux.lds.h alpha: no need to include asm/xchg.h twice
| * runtime constants: move list of constants to vmlinux.lds.hJann Horn2024-08-191-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | Refactor the list of constant variables into a macro. This should make it easier to add more constants in the future. Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* | Merge tag 's390-6.12-1' of ↵Linus Torvalds2024-09-2123-370/+1137
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Optimize ftrace and kprobes code patching and avoid stop machine for kprobes if sequential instruction fetching facility is available - Add hiperdispatch feature to dynamically adjust CPU capacity in vertical polarization to improve scheduling efficiency and overall performance. Also add infrastructure for handling warning track interrupts (WTI), allowing for graceful CPU preemption - Rework crypto code pkey module and split it into separate, independent modules for sysfs, PCKMO, CCA, and EP11, allowing modules to load only when the relevant hardware is available - Add hardware acceleration for HMAC modes and the full AES-XTS cipher, utilizing message-security assist extensions (MSA) 10 and 11. It introduces new shash implementations for HMAC-SHA224/256/384/512 and registers the hardware-accelerated AES-XTS cipher as the preferred option. Also add clear key token support - Add MSA 10 and 11 processor activity instrumentation counters to perf and update PAI Extension 1 NNPA counters - Cleanup cpu sampling facility code and rework debug/WARN_ON_ONCE statements - Add support for SHA3 performance enhancements introduced with MSA 12 - Add support for the query authentication information feature of MSA 13 and introduce the KDSA CPACF instruction. Provide query and query authentication information in sysfs, enabling tools like cpacfinfo to present this data in a human-readable form - Update kernel disassembler instructions - Always enable EXPOLINE_EXTERN if supported by the compiler to ensure kpatch compatibility - Add missing warning handling and relocated lowcore support to the early program check handler - Optimize ftrace_return_address() and avoid calling unwinder - Make modules use kernel ftrace trampolines - Strip relocs from the final vmlinux ELF file to make it roughly 2 times smaller - Dump register contents and call trace for early crashes to the console - Generate ptdump address marker array dynamically - Fix rcu_sched stalls that might occur when adding or removing large amounts of pages at once to or from the CMM balloon - Fix deadlock caused by recursive lock of the AP bus scan mutex - Unify sync and async register save areas in entry code - Cleanup debug prints in crypto code - Various cleanup and sanitizing patches for the decompressor - Various small ftrace cleanups * tag 's390-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (84 commits) s390/crypto: Display Query and Query Authentication Information in sysfs s390/crypto: Add Support for Query Authentication Information s390/crypto: Rework RRE and RRF CPACF inline functions s390/crypto: Add KDSA CPACF Instruction s390/disassembler: Remove duplicate instruction format RSY_RDRU s390/boot: Move boot_printk() code to own file s390/boot: Use boot_printk() instead of sclp_early_printk() s390/boot: Rename decompressor_printk() to boot_printk() s390/boot: Compile all files with the same march flag s390: Use MARCH_HAS_*_FEATURES defines s390: Provide MARCH_HAS_*_FEATURES defines s390/facility: Disable compile time optimization for decompressor code s390/boot: Increase minimum architecture to z10 s390/als: Remove obsolete comment s390/sha3: Fix SHA3 selftests failures s390/pkey: Add AES xts and HMAC clear key token support s390/cpacf: Add MSA 10 and 11 new PCKMO functions s390/mm: Add cond_resched() to cmm_alloc/free_pages() s390/pai_ext: Update PAI extension 1 counters s390/pai_crypto: Add support for MSA 10 and 11 pai counters ...
| * | s390/crypto: Display Query and Query Authentication Information in sysfsFinn Callies2024-09-122-0/+120
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Displays the query (fc=0) and query authentication information (fc=127) as binary in sysfs per CPACF instruction. Files are located in /sys/devices/system/cpu/cpacf/. These information can be fetched via asm already except for PCKMO because this instruction is privileged. To offer a unified interface all CPACF instructions will have this information displayed in sysfs in files <instruction>_query_raw and <instruction>_query_auth_info_raw. A new tool introduced into s390-tools called cpacfinfo will use this information to convert and display in human readable form. Suggested-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Finn Callies <fcallies@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/disassembler: Remove duplicate instruction format RSY_RDRUJens Remus2024-09-121-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instruction format RSY_RDRU is a duplicate of RSY_RURD2. Use the latter, as it follows the s390-specific conventions for instruction format naming used in binutils. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390: Use MARCH_HAS_*_FEATURES definesHeiko Carstens2024-09-071-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Replace CONFIG_HAVE_MARCH_*_FEATURES with MARCH_HAS_*_FEATURES everywhere so code gets compiled correctly depending on if the target is the kernel or the decompressor. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai_ext: Update PAI extension 1 countersThomas Richter2024-09-051-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the internal array of PAI extension 1 NNPA counter string table to support specialized processor instrumentation assist instructions. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pai_crypto: Add support for MSA 10 and 11 pai countersThomas Richter2024-09-051-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the internal array of PAI crypto counter string table with new counters supported with Message Security Assist extension (MSA) 10 and MSA 11. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Finn Callies <fcallies@linux.ibm.com> Tested-by: Finn Callies <fcallies@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/hiperdispatch: Add hiperdispatch debug countersMete Durlu2024-08-291-0/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add three counters to follow and understand hiperdispatch behavior; * adjustment_count (amount of capacity adjustments triggered) * greedy_time_ms (time spent while all cpus are on high capacity) * conservative_time_ms (time spent while only entitled cpus are on high capacity) These counters can be found under /sys/kernel/debug/s390/hiperdispatch/ Time counters are in <msec> format and only cover the time spent when hiperdispatch is active. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/hiperdispatch: Add hiperdispatch debug attributesMete Durlu2024-08-291-2/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add two attributes for debug purposes. They can be found under; /sys/devices/system/cpu/hiperdispatch/ * hd_stime_threshold : allows user to adjust steal time threshold * hd_delay_factor : allows user to adjust delay factor of hiperdispatch work (after topology updates, delayed work is always delayed extra by this factor) hd_stime_threshold can have values between 0-100 as it represents a percentage value. hd_delay_factor can have values greater than 1. It is multiplied with the default delay to achieve a longer interval, pushing back the next hiperdispatch adjustment after a topology update. Ex: if delay interval is 250ms and the delay factor is 4; delayed interval is now 1000ms(1sec). After each capacity adjustment or topology change, work has a delayed interval of 1 sec for one interval. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/hiperdispatch: Add hiperdispatch sysctl interfaceMete Durlu2024-08-291-0/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Expose hiperdispatch controls via sysctl. The user can now toggle hiperdispatch via assigning 0 or 1 to s390.hiperdispatch attribute. When hiperdipatch is toggled on, it tries to adjust CPU capacities, while system is in vertical polarization to gain performance benefits from different CPU polarizations. Disabling hiperdispatch reverts the CPU capacities to their default (HIGH_CAPACITY) and stops the dynamic adjustments. Introduce a kconfig option HIPERDISPATCH_ON which allows users to use hiperdispatch by default on vertical polarization. Using the sysctl attribute s390.hiperdispatch would overwrite this behavior. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/hiperdispatch: Add trace eventsMete Durlu2024-08-291-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add trace events to debug hiperdispatch behavior and track domain rebuilding. Two events provide information about the decision making of hiperdispatch and the adjustments made. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Co-developed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/hiperdispatch: Add steal time averagingMete Durlu2024-08-291-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The measurements done by hiperdispatch can have sudden spikes and dips during run time. To prevent these outliers effecting the decision making process and causing adjustment overhead, use weighted average of the steal time. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Co-developed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/hiperdispatch: Introduce hiperdispatchMete Durlu2024-08-293-5/+214
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When LPAR is in vertical polarization, CPUs get different polarization values, namely vertical high, vertical medium and vertical low. These values represent the likelyhood of the CPU getting physical runtime. Vertical high CPUs will always get runtime and others get varying runtime depending on the load the CEC is under. Vertical high and vertical medium CPUs are considered the CPUs which the current LPAR has the entitlement to run on. The vertical lows are on the other hand are borrowed CPUs which would only be given to the LPAR by hipervisor when the other LPARs are not utilizing them. Using the CPU capacities, hint linux scheduler when it should prioritise vertical high and vertical medium CPUs over vertical low CPUs. By tracking various system statistics hiperdispatch determines when to adjust cpu capacities. After each adjustment, rebuilding of scheduler domains is necessary to notify the scheduler about capacity changes but since this operation is costly it should be done as sparsely as possible. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Co-developed-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/smp: Add cpu capacitiesMete Durlu2024-08-291-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux scheduler allows architectures to assign capacity values to individual CPUs. This hints scheduler the performance difference between CPUs and allows more efficient task distribution them. Implement helper methods to set and get CPU capacities for s390. This is particularly helpful in vertical polarization configurations of LPARs. On vertical polarization an LPARs CPUs can get different polarization values depending on the CEC configuration. CPUs with different polarization values can perform different from each other, using CPU capacities this can be reflected to linux scheduler. Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/topology: Add config option to switch to vertical during bootTobias Huschle2024-08-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By default, all systems on s390 start in horizontal cpu polarization. Selecting the new config option SCHED_TOPOLOGY_VERTICAL allows to build a kernel that switches to vertical polarization during boot. Acked-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/topology: Add sysctl handler for polarizationTobias Huschle2024-08-291-13/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide an additional path to set the polarization of the system, such that a user no longer relies on the sysfs interface only and is able configure the polarization for every reboot via sysctl control files. The new sysctl can be set as follows: - s390.polarization=0 for horizontal polarization - s390.polarization=1 for vertical polarization Acked-by: Heiko Carstens <hca@linux.ibm.com> Tested-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/wti: Add debugfs file to display missed grace periods per cpuTobias Huschle2024-08-291-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new debug file which allows to determine how many warning track grace periods were missed on each CPU. The new file can be found as /sys/kernel/debug/s390/wti It is formatted as: CPU0 CPU1 [...] CPUx xyz xyz [...] xyz Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/wti: Add wti accounting for missed grace periodsTobias Huschle2024-08-291-1/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A virtual CPU that has received a warning-track interrupt may fail to acknowledge the interrupt within the warning-track grace period. While this is usually not a problem, it will become necessary to investigate if there is a large number of such missed warning-track interrupts. Therefore, it is necessary to track these events. The information is tracked through the s390 debug facility and can be found under /sys/kernel/debug/s390dbf/wti/. The hex_ascii output is formatted as: <pid> <symbol> The values pid and current psw are collected when a warning track interrupt is received. Symbol is either the kernel symbol matching the collected psw or redacted to <user> when running in user space. Each line represents the currently executing process when a warning track interrupt was received which was then not acknowledged within its grace period. Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/wti: Prepare graceful CPU pre-emption on wti receptionTobias Huschle2024-08-292-1/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a warning track interrupt is received, the kernel has only a very limited amount of time to make sure, that the CPU can be yielded as gracefully as possible before being pre-empted by the hypervisor. The interrupt handler for the wti therefore unparks a kernel thread which has being created on boot re-using the CPU hotplug kernel thread infrastructure. These threads exist per CPU and are assigned the highest possible real-time priority. This makes sure, that said threads will execute as soon as possible as the scheduler should pre-empt any other running user tasks to run the real-time thread. Furthermore, the interrupt handler disables all I/O interrupts to prevent additional interrupt processing on the soon-preempted CPU. Interrupt handlers are likely to take kernel locks, which in the worst case, will be kept while the interrupt handler is pre-empted from itself underlying physical CPU. In that case, all tasks or interrupt handlers on other CPUs would have to wait for the pre-empted CPU being dispatched again. By preventing further interrupt processing, this risk is minimized. Once the CPU gets dispatched again, the real-time kernel thread regains control, reenables interrupts and parks itself again. Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/wti: Introduce infrastructure for warning track interruptTobias Huschle2024-08-292-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The warning-track interrupt (wti) provides a notification that the receiving CPU will be pre-empted from its physical CPU within a short time frame. This time frame is called grace period and depends on the machine type. Giving up the CPU on time may prevent a task to get stuck while holding a resource. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Mete Durlu <meted@linux.ibm.com> Signed-off-by: Tobias Huschle <huschle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/ftrace: Avoid extra serialization for graph caller patchingVasily Gorbik2024-08-291-14/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only context where ftrace_enable_ftrace_graph_caller() or ftrace_disable_ftrace_graph_caller() is called also calls ftrace_arch_code_modify_post_process(), which already performs text_poke_sync_lock(). ftrace_run_update_code() arch_ftrace_update_code() ftrace_modify_all_code() ftrace_enable_ftrace_graph_caller()/ftrace_disable_ftrace_graph_caller() ftrace_arch_code_modify_post_process() text_poke_sync_lock() Remove the redundant serialization. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/ftrace: Use get/copy_from_kernel_nofault consistentlyVasily Gorbik2024-08-291-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use get/copy_from_kernel_nofault to access the kernel text consistently. Replace memcmp() in ftrace_init_nop() to ensure that in case of inconsistencies in the 'mcount' table, the kernel reports a failure instead of potentially crashing. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/ftrace: Avoid trampolines if possibleVasily Gorbik2024-08-291-6/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | When a sequential instruction fetching facility is present, it is safe to patch ftrace NOPs in function prologues. All of them are 8-byte aligned. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/kprobes: Avoid stop machine if possibleVasily Gorbik2024-08-291-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | Avoid stop machine on kprobes arm/disarm when sequential instruction fetching is present. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/setup: Recognize sequential instruction fetching facilityVasily Gorbik2024-08-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When sequential instruction fetching facility is present, certain guarantees are provided for code patching. In particular, atomic overwrites within 8 aligned bytes is safe from an instruction-fetching point of view. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/entry: Unify save_area_sync and save_area_asyncSven Schnelle2024-08-292-13/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the past two save areas existed because interrupt handlers and system call / program check handlers where entered with interrupts enabled. To prevent a handler from overwriting the save areas from the previous handler, interrupts used the async save area, while system call and program check handler used the sync save area. Since the removal of critical section cleanup from entry.S, handlers are entered with interrupts disabled. When the interrupts are re-enabled, the save area is no longer need. Therefore merge both save areas into one. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/disassembler: Add instructionsVasily Gorbik2024-08-291-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | Add more instructions to the kernel disassembler. Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/disassembler: Use proper format specifiers for operand valuesJens Remus2024-08-291-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Treat register numbers as unsigned. Treat signed operand values as signed. This resolves multiple instances of the Cppcheck warning: warning: %i in format string (no. 1) requires 'int' but the argument type is 'unsigned int'. [invalidPrintfArgType_sint] Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/ftrace: Avoid calling unwinder in ftrace_return_address()Vasily Gorbik2024-08-271-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ftrace_return_address() is called extremely often from performance-critical code paths when debugging features like CONFIG_TRACE_IRQFLAGS are enabled. For example, with debug_defconfig, ftrace selftests on my LPAR currently execute ftrace_return_address() as follows: ftrace_return_address(0) - 0 times (common code uses __builtin_return_address(0) instead) ftrace_return_address(1) - 2,986,805,401 times (with this patch applied) ftrace_return_address(2) - 140 times ftrace_return_address(>2) - 0 times The use of __builtin_return_address(n) was replaced by return_address() with an unwinder call by commit cae74ba8c295 ("s390/ftrace: Use unwinder instead of __builtin_return_address()") because __builtin_return_address(n) simply walks the stack backchain and doesn't check for reaching the stack top. For shallow stacks with fewer than "n" frames, this results in reads at low addresses and random memory accesses. While calling the fully functional unwinder "works", it is very slow for this purpose. Moreover, potentially following stack switches and walking past IRQ context is simply wrong thing to do for ftrace_return_address(). Reimplement return_address() to essentially be __builtin_return_address(n) with checks for reaching the stack top. Since the ftrace_return_address(n) argument is always a constant, keep the implementation in the header, allowing both GCC and Clang to unroll the loop and optimize it to the bare minimum. Fixes: cae74ba8c295 ("s390/ftrace: Use unwinder instead of __builtin_return_address()") Cc: stable@vger.kernel.org Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/ftrace: Use kernel ftrace trampoline for modulesVasily Gorbik2024-08-271-24/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that both the kernel modules area and the kernel image itself are located within 4 GB, there is no longer a need to maintain a separate ftrace_plt trampoline. Use the existing trampoline in the kernel. Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/ftrace: Remove unused ftrace_plt_template*Vasily Gorbik2024-08-271-2/+0
| | | | | | | | | | | | | | | | | | | | | Unused since commit b860b9346e2d ("s390/ftrace: remove dead code"). Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/early: Dump register contents and call trace for early crashesHeiko Carstens2024-08-222-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the early program check handler cannot resolve a program check dump register contents and a call trace to the console before loading a disabled wait psw. This makes debugging much easier. Emit an extra message with early_printk() for cases where regular printk() via the early console is not yet working so that at least some information is available. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/early: Add __init to __do_early_pgm_check()Heiko Carstens2024-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | __do_early_pgm_check() is a function which is only needed during early setup code. Mark it __init in order to save a few bytes. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/cpum_sf: Remove WARN_ON_ONCE statementsThomas Richter2024-08-221-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove WARN_ON_ONCE statements. These have not triggered in the past. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/cpum_sf: Rework debug_sprintf_event() messagesThomas Richter2024-08-221-137/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rework debug messages: - Remove most of the debug_sprintf_event() invocations. - Do not split string format statements - Remove colon after function name. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/cpum_sf: Ignore qsi() return codeThomas Richter2024-08-211-51/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | qsi() executes the instruction qsi (query sample information) and stores the result of the query in a sample information block pointed to by the function argument. The instruction does not change the condition code register. The return code is always zero. No need to check for errors. Remove now unreferenced macros PMC_FAILURE and RS_INIT_FAILURE_QSI. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/cpum_sf: Ignore lsctl() return code in sf_disable()Thomas Richter2024-08-211-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sf_disable() returns the condition code of instruction lsctl (load sampling controls). However the parameter to lsctl() in sf_disable() is a sample control block containing all zeroes. This invocation of lsctl() does not fail and returns always zero even when there is no authorization for sampling on the machine. In short, sampling can be always turned off. Ignore the return code of sf_disable() and change the function return to void. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/entry: Move early_pgm_check_handler() to init text sectionHeiko Carstens2024-08-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Save some bytes and move early_pgm_check_handler() to init text section. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/traps: Handle early warnings gracefullyHeiko Carstens2024-08-071-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add missing warning handling to the early program check handler. This way a warning is printed to the console as soon as the early console is setup, and the kernel continues to boot. Before this change a disabled wait psw was loaded instead and the machine was silently stopped without giving an idea about what happened. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/entry: Make early program check handler relocated lowcore awareHeiko Carstens2024-08-072-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the missing pieces so the early program check handler also works with a relocated lowcore. Right now the result of an early program check in case of a relocated lowcore would be a program check loop. Fixes: 8f1e70adb1a3 ("s390/boot: Add cmdline option to relocate lowcore") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| * | s390/entry: Move early program check handler to entry.SHeiko Carstens2024-08-073-24/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | Have all program check handlers in one file to make future changes easy. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-23 14:07:17 +0000