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2024-12-10s390/Kconfig: Select VMAP_STACK unconditionallyHeiko Carstens1-18/+2
There is no point in supporting !VMAP_STACK kernel builds. VMAP_STACK has proven to work since many years. Also, since KASAN_VMALLOC is supported, kernels built with !VMAP_STACK are completely untested. Therefore select VMAP_STACK unconditionally and remove all config options and code required for !VMAP_STACK builds. Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-11-21s390/entry: Mark IRQ entries to fix stack depot warningsVasily Gorbik1-0/+4
The stack depot filters out everything outside of the top interrupt context as an uninteresting or irrelevant part of the stack traces. This helps with stack trace de-duplication, avoiding an explosion of saved stack traces that share the same IRQ context code path but originate from different randomly interrupted points, eventually exhausting the stack depot. Filtering uses in_irqentry_text() to identify functions within the .irqentry.text and .softirqentry.text sections, which then become the last stack trace entries being saved. While __do_softirq() is placed into the .softirqentry.text section by common code, populating .irqentry.text is architecture-specific. Currently, the .irqentry.text section on s390 is empty, which prevents stack depot filtering and de-duplication and could result in warnings like: Stack depot reached limit capacity WARNING: CPU: 0 PID: 286113 at lib/stackdepot.c:252 depot_alloc_stack+0x39a/0x3c8 with PREEMPT and KASAN enabled. Fix this by moving the IO/EXT interrupt handlers from .kprobes.text into the .irqentry.text section and updating the kprobes blacklist to include the .irqentry.text section. This is done only for asynchronous interrupts and explicitly not for program checks, which are synchronous and where the context beyond the program check is important to preserve. Despite machine checks being somewhat in between, they are extremely rare, and preserving context when possible is also of value. SVCs and Restart Interrupts are not relevant, one being always at the boundary to user space and the other being a one-time thing. IRQ entries filtering is also optionally used in ftrace function graph, where the same logic applies. Cc: stable@vger.kernel.org # 5.15+ Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm/fault: Handle guest-related program interrupts in KVMClaudio Imbrenda1-23/+1
Any program interrupt that happens in the host during the execution of a KVM guest will now short circuit the fault handler and return to KVM immediately. Guest fault handling (including pfault) will happen entirely inside KVM. When sie64a() returns zero, current->thread.gmap_int_code will contain the program interrupt number that caused the exit, or zero if the exit was not caused by a host program interrupt. KVM will now take care of handling all guest faults in vcpu_post_run(). Since gmap faults will not be visible by the rest of the kernel, remove GMAP_FAULT, the linux fault handlers for secure execution faults, the exception table entries for the sie instruction, the nop padding after the sie instruction, and all other references to guest faults from the s390 code. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-6-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/entry: Remove __GMAP_ASCE and use _PIF_GUEST_FAULT againClaudio Imbrenda1-12/+14
Now that the guest ASCE is passed as a parameter to __sie64a(), _PIF_GUEST_FAULT can be used again to determine whether the fault was a guest or host fault. Since the guest ASCE will not be taken from the gmap pointer in lowcore anymore, __GMAP_ASCE can be removed. For the same reason the guest ASCE needs now to be saved into the cr1 save area unconditionally. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-2-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-09-21Merge tag 's390-6.12-1' of ↵Linus Torvalds1-9/+27
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 ...
2024-09-13s390/alternatives: Remove ALT_FACILITY_EARLYHeiko Carstens1-1/+1
Patch all alternatives which depend on facilities from the decompressor. There is no technical reason which enforces to split patching of such alternatives to the decompressor and the kernel. This simplifies alternative handling a bit, since one alternative type is removed. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-08-29s390/entry: Unify save_area_sync and save_area_asyncSven Schnelle1-11/+11
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>
2024-08-07s390/entry: Move early_pgm_check_handler() to init text sectionHeiko Carstens1-0/+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>
2024-08-07s390/entry: Make early program check handler relocated lowcore awareHeiko Carstens1-5/+6
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>
2024-08-07s390/entry: Move early program check handler to entry.SHeiko Carstens1-0/+15
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>
2024-07-23s390/entry: Make system_call() ready for lowcore relocationSven Schnelle1-10/+11
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in system_call(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make ret_from_fork() ready for lowcore relocationSven Schnelle1-3/+4
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in ret_from_fork(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make __switch_to() ready for lowcore relocationSven Schnelle1-4/+5
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in __switch_to(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make restart_int_handler() ready for lowcore relocationSven Schnelle1-6/+8
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in restart_int_handler(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make mchk_int_handler() ready for lowcore relocationSven Schnelle1-23/+25
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in mcck_int_handler(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make int handlers ready for lowcore relocationSven Schnelle1-15/+16
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in the ext/io interrupt handlers. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make pgm_check_handler() ready for lowcore relocationSven Schnelle1-21/+26
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in pgm_check_handler(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Add base register to CHECK_VMAP_STACK/CHECK_STACK macroSven Schnelle1-12/+12
In preparation of having lowcore at different address than zero, add the base register to CHECK_VMAP_STACK and CHECK_STACK. No functional change, because %r0 is passed to the macro. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Add base register to SIEEXIT macroSven Schnelle1-8/+8
In preparation of having lowcore at different address than zero, add the base register to SIEEXIT. No functional change, because %r0 is passed to the macro. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Add base register to MBEAR macroSven Schnelle1-4/+5
In preparation of having lowcore at different address than zero, add the base register to MBEAR. No functional change, because %r0 is passed to the macro. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Make __sie64a() ready for lowcore relocationSven Schnelle1-3/+6
In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in __sie64a(). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/entry: Move SIE indicator flag to thread infoHeiko Carstens1-8/+12
CIF_SIE indicates if a thread is running in SIE context. This is the state of a thread and not the CPU. Therefore move this indicator to thread info. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/nmi: Simplify ptregs setupHeiko Carstens1-3/+2
The low level machine check handler code fills the ptregs structure partially with the register contents present at machine check handler entry and partially with contents from the machine check save area. In case of a machine check the contents of all general purpose registers are saved by the CPU to the machine check save area. Therefore simplify the code and fill the ptregs structure by only using the machine check save area as source. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-23s390/nospec: Push down alternative handlingHeiko Carstens1-4/+4
The nospec implementation is deeply integrated into the alternatives code: only for nospec an alternative facility list is implemented and used by the alternative code, while it is modified by nospec specific needs. Push down the nospec alternative handling into the nospec by introducing a new alternative type and a specific nospec callback to decide if alternatives should be applied. Also introduce a new global nobp variable which together with facility 82 can be used to decide if nobp is enabled or not. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-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>
2024-07-23s390/alternatives: Rework to allow for callbacksHeiko Carstens1-11/+11
Rework alternatives to allow for callbacks. With this every alternative entry has additional data encoded: - When (aka context) an alternative is supposed to be applied - The type of an alternative, which allows for type specific handling and callbacks - Extra type specific payload (patch information), which can be passed to callbacks in order to decide if an alternative should be applied or not With this only the "late" context is implemented, which means there is no change to the previous behaviour. All code is just converted to the more generic new infrastructure. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-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>
2024-07-23s390/alternatives: Merge both alternative header filesHeiko Carstens1-1/+1
The two alternative header files must stay in sync. This is easier to achieve within one header file. Therefore merge both of them and have only one file, like most other architectures. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Tested-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>
2024-07-23s390: Move CIF flags to struct pcpuSven Schnelle1-1/+2
To allow testing flags for offline CPUs, move the CIF flags to struct pcpu. To avoid having to calculate the array index for each access, add a pointer to the pcpu member for the current cpu to lowcore. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-10s390/entry: Pass the asce as parameter to sie64a()Claudio Imbrenda1-5/+3
Pass the guest ASCE explicitly as parameter, instead of having sie64a() take it from lowcore. This removes hidden state from lowcore, and makes things look cleaner. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Link: https://lore.kernel.org/r/20240703155900.103783-2-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-05-14s390/idle: Rewrite psw_idle() in CSven Schnelle1-23/+0
To ease maintenance and further enhancements, convert the psw_idle() function to C. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17s390/mm: Fix NULL pointer dereferenceSven Schnelle1-1/+2
The recently added check to figure out if a fault happened on gmap ASCE dereferences the gmap pointer in lowcore without checking that it is not NULL. For all non-KVM processes the pointer is NULL, so that some value from lowcore will be read. With the current layouts of struct gmap and struct lowcore the read value (aka ASCE) is zero, so that this doesn't lead to any observable bug; at least currently. Fix this by adding the missing NULL pointer check. Fixes: 64c3431808bd ("s390/entry: compare gmap asce to determine guest/host fault") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-03s390/entry: align system call table on 8 bytesSumanth Korikkar1-0/+1
Align system call table on 8 bytes. With sys_call_table entry size of 8 bytes that eliminates the possibility of a system call pointer crossing cache line boundary. Cc: stable@kernel.org Suggested-by: Ulrich Weigand <ulrich.weigand@de.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-03-17s390/entry: compare gmap asce to determine guest/host faultSven Schnelle1-16/+15
With the current implementation, there are some cornercases where a host fault would be treated as a guest fault, for example when the sie instruction causes a program check. Therefore store the gmap asce in ptregs, and use that to compare the primary asce from the fault instead of matching instruction addresses. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-17s390/entry: remove OUTSIDE macroSven Schnelle1-25/+4
With only one OUTSIDE user left, remove the macro and move the code directly to the machine check handler. This has the advantage that it is much easier to determine which registers are used. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-03-17s390/entry: add CIF_SIE flag and remove sie64a() address checkSven Schnelle1-3/+14
When a program check, interrupt or machine check is triggered, the PSW address is compared to a certain range of the sie64a() function to figure out whether SIE was interrupted and a cleanup of SIE is needed. This doesn't work with kprobes: If kprobes probes an instruction, it copies the instruction to the kprobes instruction page and overwrites the original instruction with an undefind instruction (Opcode 00). When this instruction is hit later, kprobes single-steps the instruction on the kprobes_instruction page. However, if this instruction is a relative branch instruction it will now point to a different location in memory due to being moved to the kprobes instruction page. If the new branch target points into sie64a() the kernel assumes it interrupted SIE when processing the breakpoint and will crash trying to access the SIE control block. Instead of comparing the address, introduce a new CIF_SIE flag which indicates whether SIE was interrupted. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16s390/kvm: convert to regular kernel fpu userHeiko Carstens1-2/+0
KVM modifies the kernel fpu's regs pointer to its own area to implement its custom version of preemtible kernel fpu context. With general support for preemptible kernel fpu context there is no need for the extra complexity in KVM code anymore. Therefore convert KVM to a regular kernel fpu user. In particular this means that all TIF_FPU checks can be removed, since the fpu register context will never be changed by other kernel fpu users, and also the fpu register context will be restored if a thread is preempted. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16s390/fpu: convert FPU CIF flag to regular TIF flagHeiko Carstens1-1/+1
The FPU state, as represented by the CIF_FPU flag reflects the FPU state of a task, not the CPU it is running on. Therefore convert the flag to a regular TIF flag. This removes the magic in switch_to() where a save_fpu_regs() call for the currently (previous) running task sets the per-cpu CIF_FPU flag, which is required to restore FPU register contents of the next task, when it returns to user space. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16s390/fpu: move, rename, and merge header filesHeiko Carstens1-1/+1
Move, rename, and merge the fpu and vx header files. This way fpu header files have a consistent naming scheme (fpu*.h). Also get rid of the fpu subdirectory and move header files to asm directory, so that all fpu and vx header files can be found at the same location. Merge internal.h header file into other header files, since the internal helpers are used at many locations. so those helper functions are really not internal. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-16s390/nmi: remove register validation codeHeiko Carstens1-5/+0
Remove the historic machine check handler code which validates registers. Registers are automatically validated as part of the machine check handling sequence (see Principles of Operation, Machine-Check Handling chapter, Validation). Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-12s390/switch_to: use generic header fileHeiko Carstens1-5/+5
Move the switch_to() implementation to process.c and use the generic switch_to.h header file instead, like some other architectures. This addresses also the oddity that the old switch_to() implementation assigns the return value of __switch_to() to 'prev' instead of 'last', like it should. Remove also all includes of switch_to.h from C files, except process.c. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-09s390: replace #include <asm/export.h> with #include <linux/export.h>Masahiro Yamada1-1/+1
Commit ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost") deprecated <asm/export.h>, which is now a wrapper of <linux/export.h>. Replace #include <asm/export.h> with #include <linux/export.h>. After all the <asm/export.h> lines are converted, <asm/export.h> and <asm-generic/export.h> will be removed. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20230806151641.394720-2-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-03s390/entry: remove mcck clockSven Schnelle1-1/+0
In the past machine checks where accounted as irq time. With the conversion to generic entry, it was decided to account machine checks to the current context. The stckf at the beginning of the machine check handler and the lowcore member is no longer required, therefore remove it. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-07-03s390/entry: rework entering DAT-on mode on CPU restartAlexander Gordeev1-3/+8
Instead of enforcing PSW_MASK_DAT bit on previously stored in lowcore restart_psw.mask use the PSW_KERNEL_BITS mask (which contains PSW_MASK_DAT) directly. As result, the PSW mask stored in lowcore is only used to enter the CPU restart routine, while PSW_KERNEL_BITS is used to enter the kernel code - similarily to commit 64ea2977add2 ("s390/mm: start kernel with DAT enabled"). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-06-28s390: consistently use .balign instead of .alignHeiko Carstens1-1/+1
The .align directive has inconsistent behavior across architectures. Use .balign instead everywhere. This is a no-op for s390, but with this there is no mix in using .align and .balign anymore. Future code is supposed to use only .balign. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-04-19s390/entry: use SYM* macros instead of ENTRY(), etc.Heiko Carstens1-35/+34
Consistently use the SYM* family of macros instead of the deprecated ENTRY(), ENDPROC(), etc. family of macros. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-04s390: enable HAVE_ARCH_STACKLEAKHeiko Carstens1-0/+10
Add support for the stackleak feature. Whenever the kernel returns to user space the kernel stack is filled with a poison value. Enabling this feature is quite expensive: e.g. after instrumenting the getpid() system call function to have a 4kb stack the result is an increased runtime of the system call by a factor of 3. Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-04s390/stack: use STACK_INIT_OFFSET where possibleHeiko Carstens1-8/+4
Make STACK_INIT_OFFSET also available for assembler code, and use it everywhere instead of open-coding it at several places. Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-04-04s390/entry: rely on long-displacement facilityVasily Gorbik1-5/+3
Since commit 4efd417f298b ("s390: raise minimum supported machine generation to z10"), the long-displacement facility is assumed and required for the kernel. Clean up a couple of places in the entry code, where long-displacement could be used directly instead of using a base register. However, there are still a few other places where a base register has to be used to extend short-displacement for the second lowcore page access. Notably, boot/head.S still has to be built for z900, and in mcck_int_handler, spt and lbear, which don't have long-displacements, but need to access save areas at the second lowcore page. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-03-13s390/bp: remove __bpon()Heiko Carstens1-12/+6
There is no point in changing branch prediction state of a cpu shortly before it enters stop state. Therefore remove __bpon(). Acked-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>
2023-03-13s390/bp: remove TIF_ISOLATE_BPHeiko Carstens1-23/+13
TIF_ISOLATE_BP is unused since it was introduced with commit 6b73044b2b00 ("s390: run user space and KVM guests with modified branch prediction"). Given that there is no use case remove it again. Acked-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>
2023-03-13s390/bp: add missing BPENTER to program check handlerHeiko Carstens1-0/+1
When leaving interpretive execution because of a program check BPENTER should be called like it is done on interrupt exit as well. Acked-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 2.39.1) at 2025-02-27 21:44:39 +0000