linux-toradex.git/arch/s390/include/asm, branch master

Merge tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux

2026-06-15T23:38:13+00:00

Pull s390 updates from Alexander Gordeev:

 - Use CIO device online variable instead of the internal FSM state to
   determine device availability during purge operations

 - Remove extra check of task_stack_page() because try_get_task_stack()
   already takes care of that when reading /proc//wchan

 - Allow user-space to use the new SCLP action qualifier 4 for to
   provide NVMe SMART log data to the platform.

 - Send AP CHANGE uevents on successful bind and successful association
   to notify user-space about SE operations on AP queue devices

 - Add an s390dbf kernel parameter to configure debug log levels and
   area sizes during early boot

 - On arm64 the empty zero page is going to be mapped read-only. Do the
   same for s390 with an explicit set_memory_ro() call

 - Improve s390-specific bcr_serialize() and cpu_relax() implementations

 - Remove all unused variables to avoid allmodconfig W=1 build fails
   with latest clang-23

 - Cleanup default Kconfig values for s390 selftests

 - Add a s390-tod trace clock to allow comparing trace timestamps
   between different systems or virtual machines on s390

 - Remove the s390 implementation of strlcat() in favor of the generic
   variant

 - Make consistent the calling order between
   page_table_check_pte_clear() and secure page conversion across all
   code paths

 - Rearrange some fields within AP and zcrypt structs to reduce memory
   consumption and unused holes

 - Shorten GR_NUM and VX_NUM macros and move them to a separate header

 - Replace __get_free_page() with kmalloc() in few sources

 - Introduce an infrastructure for more efficient this_cpu operations.
   Eliminate conditional branches when PREEMPT_NONE is removed

 - Enable Rust support

 - Use z10 as minimum architecture level, similar to the boot code, to
   enforce a defined architecture level set

 - Improve and convert various mem*() helper functions to C. For that
   add .noinstr.text section to avoid orphaned warnings from the linker

 - Fix the function pointer type in __ret_from_fork() to correct the
   indirect call to match kernel thread return type of int

 - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception
   loop on read from donated Ultravisor pages at unaligned addresses

* tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits)
  s390: Revert support for DCACHE_WORD_ACCESS
  s390/process: Fix kernel thread function pointer type
  s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
  s390/memmove: Optimize backward copy case
  s390/string: Convert memset(16|32|64)() to C
  s390/string: Convert memcpy() to C
  s390/string: Convert memset() to C
  s390/string: Convert memmove() to C
  s390/string: Add -ffreestanding compile option to string.o
  s390: Add .noinstr.text to boot and purgatory linker scripts
  s390/purgatory: Enforce z10 minimum architecture level
  s390: Enable Rust support
  s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
  rust: helpers: Add memchr wrapper for string operations
  rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts
  s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
  s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
  s390/ap: Fix locking issue in SE bind and associate sysfs functions
  s390/percpu: Provide arch_this_cpu_write() implementation
  s390/percpu: Provide arch_this_cpu_read() implementation
  ...

Merge tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

2026-06-15T08:18:52+00:00

Pull NOHZ updates from Thomas Gleixner:

 - Fix a long standing TOCTOU in get_cpu_sleep_time_us()

 - Make the CPU offline NOHZ handling more robust by disabling NOHZ on
   the outgoing CPU early instead of creating unneeded state which needs
   to be undone.

 - Unify idle CPU time accounting instead of having two different
   accounting mechanisms. These two different mechanisms are not really
   independent, but the different properties can in the worst case cause
   that gloabl idle time can be observed going backwards.

 - Consolidate the idle/iowait time retrieval interfaces instead of
   converting back and forth between them.

 - Make idle interrupt time accounting more robust. The original code
   assumes that interrupt time accouting is enabled and therefore stops
   elapsing idle time while an interrupt is handled in NOHZ dyntick
   state. That assumption is not correct as interrupt time accounting
   can be disabled at compile and runtime.

 - Fix an accounting error between dyntick idle time and dyntick idle
   steal time. The stolen time is not accounted and therefore idle time
   becomes inaccurate. The stolen time is now accounted after the fact
   as there is no way to predict the steal time upfront.

* tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  sched/cputime: Handle dyntick-idle steal time correctly
  sched/cputime: Handle idle irqtime gracefully
  sched/cputime: Provide get_cpu_[idle|iowait]_time_us() off-case
  tick/sched: Consolidate idle time fetching APIs
  tick/sched: Account tickless idle cputime only when tick is stopped
  tick/sched: Remove unused fields
  tick/sched: Move dyntick-idle cputime accounting to cputime code
  tick/sched: Remove nohz disabled special case in cputime fetch
  tick/sched: Unify idle cputime accounting
  s390/time: Prepare to stop elapsing in dynticks-idle
  powerpc/time: Prepare to stop elapsing in dynticks-idle
  sched/cputime: Correctly support generic vtime idle time
  sched/cputime: Remove superfluous and error prone kcpustat_field() parameter
  sched/idle: Handle offlining first in idle loop
  tick/sched: Fix TOCTOU in nohz idle time fetch

s390: Revert support for DCACHE_WORD_ACCESS

2026-06-12T09:30:25+00:00

load_unaligned_zeropad() reads eight bytes from unaligned addresses and may
cross page boundaries. It handles exceptions which may happen if reading
from the second page results in an exception.

For pages which are donated to the Ultravisor for secure execution purposes
the do_secure_storage_access() exception handler however does not handle
such exceptions correctly. Such an exception may result in an endless
exception loop which will never be resolved.

An attempt to fix this [1] turned out to be not sufficient. For now revert
load_unaligned_zeropad() until this problem has been resolved in a proper
way.

Note that the implementation of load_unaligned_zeropad() itself is
correct. The revert is just a temporary workaround until there is complete
fix for secure storage access exceptions.

[1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory")

Fixes: 802ba53eefc5 ("s390: add support for DCACHE_WORD_ACCESS")
Cc: stable@vger.kernel.org
Acked-by: Christian Borntraeger 
Signed-off-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev

s390/tishift: Convert ashlti3(), ashrti3(), __lshrti3() to C

2026-06-10T14:55:22+00:00

There is no reason to have __ashlti3(), __ashrti3(), and __lshrti3()
implemented in assembler. Convert them all to C, which allows the
compiler to optimize the code if newer instructions allow that.

Reviewed-by: Juergen Christ 
Signed-off-by: Heiko Carstens 
Signed-off-by: Alexander Gordeev

Merge branch 'rust-for-s390' into features

2026-06-10T14:53:23+00:00

Jan Polensky says:

===================
Rust support on s390 requires a small set of architecture-specific pieces
before the generic Rust kernel infrastructure can be used.

The series wires up s390 as a Rust-capable 64-bit architecture, adds the
missing assembly interfaces needed by Rust for WARN/BUG reporting and for
static branches, adjusts bindgen parameters to avoid repr layout conflicts
caused by packed and aligned s390 structures, and fixes issues discovered
during testing.

s390 currently requires rustc with support for -Zpacked-stack, and the
minimum tool version gating is adjusted accordingly.

Link: https://github.com/Rust-for-Linux/linux/issues/2

Tested against: rustc 1.96.0 (ac68faa20 2026-05-25)
===================

Signed-off-by: Alexander Gordeev

s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers

2026-06-10T14:25:13+00:00

The __arch_cmpxchg1, __arch_cmpxchg2, __arch_xchg1, and __arch_xchg2
functions emulate 1-byte and 2-byte atomic operations using 4-byte
cmpxchg instructions, since s390 lacks native 1/2-byte cmpxchg support.

When KASAN is enabled, the READ_ONCE() operations in these functions
trigger stack-out-of-bounds warnings because they perform 4-byte reads
when only 1 or 2 bytes should be accessed.

Mark these functions as __no_sanitize_or_inline to prevent KASAN
instrumentation while maintaining correct functionality.

This resolves the following KASAN error during rust_atomics KUnit tests:

  BUG: KASAN: stack-out-of-bounds in rust_helper_atomic_i8_xchg+0xb2/0xc0
  Read of size 4 at addr 001bff7ffdbefcf0 by task kunit_try_catch/142

Reported-by: Miguel Ojeda 
Link: https://lore.kernel.org/rust-for-linux/CANiq72m4GVWFYqnxNtCHTPu7XcGewHB5LNwOoayTfnXs9pPbNg@mail.gmail.com/
Suggested-by: Gary Guo 
Link: https://lore.kernel.org/rust-for-linux/DITFTAVVHTNQ.380OHUHGTOI6M@garyguo.net/
Acked-by: Heiko Carstens 
Acked-by: Gary Guo 
Signed-off-by: Jan Polensky 
Signed-off-by: Alexander Gordeev

s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros

2026-06-10T14:25:13+00:00

Rust static branch support needs the s390 jump label instruction sequence
and __jump_table emission in a reusable form. The current implementation
embeds the sequence directly in the C asm goto blocks, which cannot be
shared with Rust.

Introduce ARCH_STATIC_BRANCH_ASM and ARCH_STATIC_BRANCH_JUMP_ASM to
describe the brcl sequences for the likely-false and likely-true cases
and to emit the same __jump_table entries as before. Switch the existing
C helpers to use the new macros to avoid duplication without changing
the generated code.

Acked-by: Gary Guo 
Acked-by: Miguel Ojeda 
Acked-by: Heiko Carstens 
Reviewed-by: Alice Ryhl 
Signed-off-by: Jan Polensky 
Signed-off-by: Alexander Gordeev

s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support

2026-06-10T14:25:12+00:00

Rust WARN and BUG support relies on ARCH_WARN_ASM to emit __bug_table
entries. On s390 the macro is missing, so Rust code cannot generate
proper WARN/BUG metadata for the kernel's bug reporting infrastructure.

Define ARCH_WARN_ASM to produce the same assembly sequence and
__bug_table entry format as the existing s390 BUG handling, including
the monitor call. Define ARCH_WARN_REACHABLE as empty since s390 does
not provide reachability analysis for warning paths.

Acked-by: Gary Guo 
Acked-by: Miguel Ojeda 
Acked-by: Heiko Carstens 
Signed-off-by: Jan Polensky 
Signed-off-by: Alexander Gordeev

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2026-06-05T17:38:45+00:00

Pull kvm fixes from Paolo Bonzini:
 "arm64:
   - Correctly drop the ITS translation cache reference when it actually
     gets invalidated

   - Take the SRCU lock for SW page table walks

   - Restore POR_EL0 access to host EL0, avoiding POR_EL0 becoming
     inaccessible from EL0 after running a guest

   - Reassign nested_mmus array behind mmu_lock, ensuring that vcpu init
     and MMU notifiers are mutually exclusive

   - Correctly handle FEAT_XNX at stage-2

  s390:
   - More fixes for the new page table management and nested
     virtualization

  x86:
   - More fixes for GHCB issues:
      - Read start/end indices of page size change requests exactly once
        per vmexit
      - Unmap and unpin the GHCB as needed on vCPU free"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (23 commits)
  KVM: arm64: Correctly identify executable PTEs at stage-2
  KVM: arm64: nv: Fix handling of XN[0] when !FEAT_XNX
  KVM: arm64: Reassign nested_mmus array behind mmu_lock
  KVM: arm64: Restore POR_EL0 access to host EL0
  KVM: arm64: Take the SRCU lock for page table walks in fault injection and AT emulation
  KVM: arm64: vgic-its: Drop the translation cache reference only for the erased entry
  KVM: SEV: Unmap and unpin the GHCB as needed on vCPU free
  KVM: SEV: Decouple the need to sync the GHCB SA from the need to free the SA
  KVM: SEV: Move sev_free_vcpu() down below sev_es_unmap_ghcb()
  KVM: Don't WARN if memory is dirtied without a vCPU when the VM is dying
  KVM: SEV: Read start/end indices of PSC requests exactly once per #VMGEXIT
  KVM: SEV: Add an anonymous "psc" struct to track current PSC metadata
  KVM: SEV: Make it more obvious when KVM is writing back the current PSC index
  KVM: s390: Remove ptep_zap_softleaf_entry()
  KVM: s390: Fix possible reference leak in fault-in code
  KVM: s390: Prevent memslots outside the ASCE range
  KVM: s390: Lock pte when making page secure
  KVM: s390: Fix fault-in code
  KVM: s390: vsie: Fix rmap handling in _do_shadow_crste()
  KVM: s390: Fix guest / virtual address confusion in _essa_clear_cbrl()
  ...

Merge tag 's390-7.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2026-06-04T19:31:20+00:00

Pull s390 fixes from Alexander Gordeev:

 - Enable IOMMUFD and VFIO cdev such that PCI pass-through to
   QEMU/KVM can optionally utilize native IOMMUFD

 - With HAVE_ARCH_BUG_FORMAT enabled the BUG infrastructure might
   misinterpret flags or fault. Fix this by moving the "format"
   field emission into __BUG_ENTRY()

 - The generic version of _THIS_IP_ is known to be brittle and may
   break with current and future GCC and Clang optimizations.  Fix
   it by overriding _THIS_IP_

* tag 's390-7.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: Implement _THIS_IP_ using inline asm
  s390/bug: Always emit format word in __BUG_ENTRY
  s390/configs: Enable IOMMUFD and VFIO cdev in defconfigs