Development tree for the kernel CSPRNG https://git.zx2c4.com/linux-rng/atom/tools/testing?h=master 2025-12-03T01:03:55Z 2025-12-03T01:03:55Z Linus Torvalds torvalds@linux-foundation.org 2025-12-03T01:03:55Z urn:sha1:44fc84337b6eae580a51cf6f7ca6a22ef1349556 Pull arm64 updates from Catalin Marinas: "These are the arm64 updates for 6.19. The biggest part is the Arm MPAM driver under drivers/resctrl/. There's a patch touching mm/ to handle spurious faults for huge pmd (similar to the pte version). The corresponding arm64 part allows us to avoid the TLB maintenance if a (huge) page is reused after a write fault. There's EFI refactoring to allow runtime services with preemption enabled and the rest is the usual perf/PMU updates and several cleanups/typos. Summary: Core features: - Basic Arm MPAM (Memory system resource Partitioning And Monitoring) driver under drivers/resctrl/ which makes use of the fs/rectrl/ API Perf and PMU: - Avoid cycle counter on multi-threaded CPUs - Extend CSPMU device probing and add additional filtering support for NVIDIA implementations - Add support for the PMUs on the NoC S3 interconnect - Add additional compatible strings for new Cortex and C1 CPUs - Add support for data source filtering to the SPE driver - Add support for i.MX8QM and "DB" PMU in the imx PMU driver Memory managemennt: - Avoid broadcast TLBI if page reused in write fault - Elide TLB invalidation if the old PTE was not valid - Drop redundant cpu_set_*_tcr_t0sz() macros - Propagate pgtable_alloc() errors outside of __create_pgd_mapping() - Propagate return value from __change_memory_common() ACPI and EFI: - Call EFI runtime services without disabling preemption - Remove unused ACPI function Miscellaneous: - ptrace support to disable streaming on SME-only systems - Improve sysreg generation to include a 'Prefix' descriptor - Replace __ASSEMBLY__ with __ASSEMBLER__ - Align register dumps in the kselftest zt-test - Remove some no longer used macros/functions - Various spelling corrections" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits) arm64/mm: Document why linear map split failure upon vm_reset_perms is not problematic arm64/pageattr: Propagate return value from __change_memory_common arm64/sysreg: Remove unused define ARM64_FEATURE_FIELD_BITS KVM: arm64: selftests: Consider all 7 possible levels of cache KVM: arm64: selftests: Remove ARM64_FEATURE_FIELD_BITS and its last user arm64: atomics: lse: Remove unused parameters from ATOMIC_FETCH_OP_AND macros Documentation/arm64: Fix the typo of register names ACPI: GTDT: Get rid of acpi_arch_timer_mem_init() perf: arm_spe: Add support for filtering on data source perf: Add perf_event_attr::config4 perf/imx_ddr: Add support for PMU in DB (system interconnects) perf/imx_ddr: Get and enable optional clks perf/imx_ddr: Move ida_alloc() from ddr_perf_init() to ddr_perf_probe() dt-bindings: perf: fsl-imx-ddr: Add compatible string for i.MX8QM, i.MX8QXP and i.MX8DXL arm64: remove duplicate ARCH_HAS_MEM_ENCRYPT arm64: mm: use untagged address to calculate page index MAINTAINERS: new entry for MPAM Driver arm_mpam: Add kunit tests for props_mismatch() arm_mpam: Add kunit test for bitmap reset arm_mpam: Add helper to reset saved mbwu state ... 2025-12-03T00:37:00Z Linus Torvalds torvalds@linux-foundation.org 2025-12-03T00:37:00Z urn:sha1:2547f79b0b0cd969ae6f736890af4ebd9368cda5 Pull s390 updates from Heiko Carstens: - Provide a new interface for dynamic configuration and deconfiguration of hotplug memory, allowing with and without memmap_on_memory support. This makes the way memory hotplug is handled on s390 much more similar to other architectures - Remove compat support. There shouldn't be any compat user space around anymore, therefore get rid of a lot of code which also doesn't need to be tested anymore - Add stackprotector support. GCC 16 will get new compiler options, which allow to generate code required for kernel stackprotector support - Merge pai_crypto and pai_ext PMU drivers into a new driver. This removes a lot of duplicated code. The new driver is also extendable and allows to support new PMUs - Add driver override support for AP queues - Rework and extend zcrypt and AP trace events to allow for tracing of crypto requests - Support block sizes larger than 65535 bytes for CCW tape devices - Since the rework of the virtual kernel address space the module area and the kernel image are within the same 4GB area. This eliminates the need of weak per cpu variables. Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU - Various other small improvements and fixes * tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (92 commits) watchdog: diag288_wdt: Remove KMSG_COMPONENT macro s390/entry: Use lay instead of aghik s390/vdso: Get rid of -m64 flag handling s390/vdso: Rename vdso64 to vdso s390: Rename head64.S to head.S s390/vdso: Use common STABS_DEBUG and DWARF_DEBUG macros s390: Add stackprotector support s390/modules: Simplify module_finalize() slightly s390: Remove KMSG_COMPONENT macro s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU s390/ap: Restrict driver_override versus apmask and aqmask use s390/ap: Rename mutex ap_perms_mutex to ap_attr_mutex s390/ap: Support driver_override for AP queue devices s390/ap: Use all-bits-one apmask/aqmask for vfio in_use() checks s390/debug: Update description of resize operation s390/syscalls: Switch to generic system call table generation s390/syscalls: Remove system call table pointer from thread_struct s390/uapi: Remove 31 bit support from uapi header files s390: Remove compat support tools: Remove s390 compat support ... 2025-12-02T22:48:08Z Linus Torvalds torvalds@linux-foundation.org 2025-12-02T22:48:08Z urn:sha1:d61f1cc5db799f4e44a63418b2dc19396787427b Pull x86 CPU feature updates from Dave Hansen: "The biggest thing of note here is Linear Address Space Separation (LASS). It represents the first time I can think of that the upper=>kernel/lower=>user address space convention is actually recognized by the hardware on x86. It ensures that userspace can not even get the hardware to _start_ page walks for the kernel address space. This, of course, is a really nice generic side channel defense. This is really only a down payment on LASS support. There are still some details to work out in its interaction with EFI calls and vsyscall emulation. For now, LASS is disabled if either of those features is compiled in (which is almost always the case). There's also one straggler commit in here which converts an under-utilized AMD CPU feature leaf into a generic Linux-defined leaf so more feature can be packed in there. Summary: - Enable Linear Address Space Separation (LASS) - Change X86_FEATURE leaf 17 from an AMD leaf to Linux-defined" * tag 'x86_cpu_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Enable LASS during CPU initialization selftests/x86: Update the negative vsyscall tests to expect a #GP x86/traps: Communicate a LASS violation in #GP message x86/kexec: Disable LASS during relocate kernel x86/alternatives: Disable LASS when patching kernel code x86/asm: Introduce inline memcpy and memset x86/cpu: Add an LASS dependency on SMAP x86/cpufeatures: Enumerate the LASS feature bits x86/cpufeatures: Make X86_FEATURE leaf 17 Linux-specific 2025-12-02T17:58:33Z Linus Torvalds torvalds@linux-foundation.org 2025-12-02T17:58:33Z urn:sha1:d42e504a555d0da2a10001e697f0c8a7f633fb05 Pull timer core updates from Thomas Gleixner: - Prevent a thundering herd problem when the timekeeper CPU is delayed and a large number of CPUs compete to acquire jiffies_lock to do the update. Limit it to one CPU with a separate "uncontended" atomic variable. - A set of improvements for the timer migration mechanism: - Support imbalanced NUMA trees correctly - Support dynamic exclusion of CPUs from the migrator duty to allow the cpuset/isolation mechanism to exclude them from handling timers of remote idle CPUs - The usual small updates, cleanups and enhancements * tag 'timers-core-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers/migration: Exclude isolated cpus from hierarchy cpumask: Add initialiser to use cleanup helpers sched/isolation: Force housekeeping if isolcpus and nohz_full don't leave any cgroup/cpuset: Rename update_unbound_workqueue_cpumask() to update_isolation_cpumasks() timers/migration: Use scoped_guard on available flag set/clear timers/migration: Add mask for CPUs available in the hierarchy timers/migration: Rename 'online' bit to 'available' selftests/timers/nanosleep: Add tests for return of remaining time selftests/timers: Clean up kernel version check in posix_timers time: Fix a few typos in time[r] related code comments time: tick-oneshot: Add missing Return and parameter descriptions to kernel-doc hrtimer: Store time as ktime_t in restart block timers/migration: Remove dead code handling idle CPU checking for remote timers timers/migration: Remove unused "cpu" parameter from tmigr_get_group() timers/migration: Assert that hotplug preparing CPU is part of stable active hierarchy timers/migration: Fix imbalanced NUMA trees timers/migration: Remove locking on group connection timers/migration: Convert "while" loops to use "for" tick/sched: Limit non-timekeeper CPUs calling jiffies update 2025-12-01T18:17:39Z Linus Torvalds torvalds@linux-foundation.org 2025-12-01T18:17:39Z urn:sha1:212c4053a1502e5117d8cbbbd1c15579ce1839bb Pull pidfd and coredump updates from Christian Brauner: "Features: - Expose coredump signal via pidfd Expose the signal that caused the coredump through the pidfd interface. The recent changes to rework coredump handling to rely on unix sockets are in the process of being used in systemd. The previous systemd coredump container interface requires the coredump file descriptor and basic information including the signal number to be sent to the container. This means the signal number needs to be available before sending the coredump to the container. - Add supported_mask field to pidfd Add a new supported_mask field to struct pidfd_info that indicates which information fields are supported by the running kernel. This allows userspace to detect feature availability without relying on error codes or kernel version checks. Cleanups: - Drop struct pidfs_exit_info and prepare to drop exit_info pointer, simplifying the internal publication mechanism for exit and coredump information retrievable via the pidfd ioctl - Use guard() for task_lock in pidfs - Reduce wait_pidfd lock scope - Add missing PIDFD_INFO_SIZE_VER1 constant - Add missing BUILD_BUG_ON() assert on struct pidfd_info Fixes: - Fix PIDFD_INFO_COREDUMP handling Selftests: - Split out coredump socket tests and common helpers into separate files for better organization - Fix userspace coredump client detection issues - Handle edge-triggered epoll correctly - Ignore ENOSPC errors in tests - Add debug logging to coredump socket tests, socket protocol tests, and test helpers - Add tests for PIDFD_INFO_COREDUMP_SIGNAL - Add tests for supported_mask field - Update pidfd header for selftests" * tag 'vfs-6.19-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits) pidfs: reduce wait_pidfd lock scope selftests/coredump: add second PIDFD_INFO_COREDUMP_SIGNAL test selftests/coredump: add first PIDFD_INFO_COREDUMP_SIGNAL test selftests/coredump: ignore ENOSPC errors selftests/coredump: add debug logging to coredump socket protocol tests selftests/coredump: add debug logging to coredump socket tests selftests/coredump: add debug logging to test helpers selftests/coredump: handle edge-triggered epoll correctly selftests/coredump: fix userspace coredump client detection selftests/coredump: fix userspace client detection selftests/coredump: split out coredump socket tests selftests/coredump: split out common helpers selftests/pidfd: add second supported_mask test selftests/pidfd: add first supported_mask test selftests/pidfd: update pidfd header pidfs: expose coredump signal pidfs: drop struct pidfs_exit_info pidfs: prepare to drop exit_info pointer pidfd: add a new supported_mask field pidfs: add missing BUILD_BUG_ON() assert on struct pidfd_info ... 2025-12-01T17:47:41Z Linus Torvalds torvalds@linux-foundation.org 2025-12-01T17:47:41Z urn:sha1:415d34b92c1f921a9ff3c38f56319cbc5536f642 Pull namespace updates from Christian Brauner: "This contains substantial namespace infrastructure changes including a new system call, active reference counting, and extensive header cleanups. The branch depends on the shared kbuild branch for -fms-extensions support. Features: - listns() system call Add a new listns() system call that allows userspace to iterate through namespaces in the system. This provides a programmatic interface to discover and inspect namespaces, addressing longstanding limitations: Currently, there is no direct way for userspace to enumerate namespaces. Applications must resort to scanning /proc/*/ns/ across all processes, which is: - Inefficient - requires iterating over all processes - Incomplete - misses namespaces not attached to any running process but kept alive by file descriptors, bind mounts, or parent references - Permission-heavy - requires access to /proc for many processes - No ordering or ownership information - No filtering per namespace type The listns() system call solves these problems: ssize_t listns(const struct ns_id_req *req, u64 *ns_ids, size_t nr_ns_ids, unsigned int flags); struct ns_id_req { __u32 size; __u32 spare; __u64 ns_id; struct /* listns */ { __u32 ns_type; __u32 spare2; __u64 user_ns_id; }; }; Features include: - Pagination support for large namespace sets - Filtering by namespace type (MNT_NS, NET_NS, USER_NS, etc.) - Filtering by owning user namespace - Permission checks respecting namespace isolation - Active Reference Counting Introduce an active reference count that tracks namespace visibility to userspace. A namespace is visible in the following cases: - The namespace is in use by a task - The namespace is persisted through a VFS object (namespace file descriptor or bind-mount) - The namespace is a hierarchical type and is the parent of child namespaces The active reference count does not regulate lifetime (that's still done by the normal reference count) - it only regulates visibility to namespace file handles and listns(). This prevents resurrection of namespaces that are pinned only for internal kernel reasons (e.g., user namespaces held by file->f_cred, lazy TLB references on idle CPUs, etc.) which should not be accessible via (1)-(3). - Unified Namespace Tree Introduce a unified tree structure for all namespaces with: - Fixed IDs assigned to initial namespaces - Lookup based solely on inode number - Maintained list of owned namespaces per user namespace - Simplified rbtree comparison helpers Cleanups - Header Reorganization: - Move namespace types into separate header (ns_common_types.h) - Decouple nstree from ns_common header - Move nstree types into separate header - Switch to new ns_tree_{node,root} structures with helper functions - Use guards for ns_tree_lock - Initial Namespace Reference Count Optimization - Make all reference counts on initial namespaces a nop to avoid pointless cacheline ping-pong for namespaces that can never go away - Drop custom reference count initialization for initial namespaces - Add NS_COMMON_INIT() macro and use it for all namespaces - pid: rely on common reference count behavior - Miscellaneous Cleanups - Rename exit_task_namespaces() to exit_nsproxy_namespaces() - Rename is_initial_namespace() and make argument const - Use boolean to indicate anonymous mount namespace - Simplify owner list iteration in nstree - nsfs: raise SB_I_NODEV, SB_I_NOEXEC, and DCACHE_DONTCACHE explicitly - nsfs: use inode_just_drop() - pidfs: raise DCACHE_DONTCACHE explicitly - pidfs: simplify PIDFD_GET__NAMESPACE ioctls - libfs: allow to specify s_d_flags - cgroup: add cgroup namespace to tree after owner is set - nsproxy: fix free_nsproxy() and simplify create_new_namespaces() Fixes: - setns(pidfd, ...) race condition Fix a subtle race when using pidfds with setns(). When the target task exits after prepare_nsset() but before commit_nsset(), the namespace's active reference count might have been dropped. If setns() then installs the namespaces, it would bump the active reference count from zero without taking the required reference on the owner namespace, leading to underflow when later decremented. The fix resurrects the ownership chain if necessary - if the caller succeeded in grabbing passive references, the setns() should succeed even if the target task exits or gets reaped. - Return EFAULT on put_user() error instead of success - Make sure references are dropped outside of RCU lock (some namespaces like mount namespace sleep when putting the last reference) - Don't skip active reference count initialization for network namespace - Add asserts for active refcount underflow - Add asserts for initial namespace reference counts (both passive and active) - ipc: enable is_ns_init_id() assertions - Fix kernel-doc comments for internal nstree functions - Selftests - 15 active reference count tests - 9 listns() functionality tests - 7 listns() permission tests - 12 inactive namespace resurrection tests - 3 threaded active reference count tests - commit_creds() active reference tests - Pagination and stress tests - EFAULT handling test - nsid tests fixes" * tag 'namespace-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (103 commits) pidfs: simplify PIDFD_GET_<type>_NAMESPACE ioctls nstree: fix kernel-doc comments for internal functions nsproxy: fix free_nsproxy() and simplify create_new_namespaces() selftests/namespaces: fix nsid tests ns: drop custom reference count initialization for initial namespaces pid: rely on common reference count behavior ns: add asserts for initial namespace active reference counts ns: add asserts for initial namespace reference counts ns: make all reference counts on initial namespace a nop ipc: enable is_ns_init_id() assertions fs: use boolean to indicate anonymous mount namespace ns: rename is_initial_namespace() ns: make is_initial_namespace() argument const nstree: use guards for ns_tree_lock nstree: simplify owner list iteration nstree: switch to new structures nstree: add helper to operate on struct ns_tree_{node,root} nstree: move nstree types into separate header nstree: decouple from ns_common header ns: move namespace types into separate header ... 2025-11-28T15:47:53Z Catalin Marinas catalin.marinas@arm.com 2025-11-28T15:47:53Z urn:sha1:52c4d1d62424c574fa048235598ce37bd4ed1e32 * for-next/sysreg: : arm64 sysreg updates/cleanups arm64/sysreg: Remove unused define ARM64_FEATURE_FIELD_BITS KVM: arm64: selftests: Consider all 7 possible levels of cache KVM: arm64: selftests: Remove ARM64_FEATURE_FIELD_BITS and its last user arm64/sysreg: Add ICH_VMCR_EL2 arm64/sysreg: Move generation of RES0/RES1/UNKN to function arm64/sysreg: Support feature-specific fields with 'Prefix' descriptor arm64/sysreg: Fix checks for incomplete sysreg definitions arm64/sysreg: Replace TCR_EL1 field macros 2025-11-28T15:47:12Z Catalin Marinas catalin.marinas@arm.com 2025-11-28T15:47:12Z urn:sha1:17c05cb0ef212d1a3c1bbbb67693a89cd9f0fb44 * arm64/for-next/perf: perf: arm_spe: Add support for filtering on data source perf: Add perf_event_attr::config4 perf/imx_ddr: Add support for PMU in DB (system interconnects) perf/imx_ddr: Get and enable optional clks perf/imx_ddr: Move ida_alloc() from ddr_perf_init() to ddr_perf_probe() dt-bindings: perf: fsl-imx-ddr: Add compatible string for i.MX8QM, i.MX8QXP and i.MX8DXL arch_topology: Provide a stub topology_core_has_smt() for !CONFIG_GENERIC_ARCH_TOPOLOGY perf/arm-ni: Fix and optimise register offset calculation perf: arm_pmuv3: Add new Cortex and C1 CPU PMUs perf: arm_cspmu: fix error handling in arm_cspmu_impl_unregister() perf/arm-ni: Add NoC S3 support perf/arm_cspmu: nvidia: Add pmevfiltr2 support perf/arm_cspmu: nvidia: Add revision id matching perf/arm_cspmu: Add pmpidr support perf/arm_cspmu: Add callback to reset filter config perf: arm_pmuv3: Don't use PMCCNTR_EL0 on SMT cores * for-next/misc: : Miscellaneous patches arm64: atomics: lse: Remove unused parameters from ATOMIC_FETCH_OP_AND macros arm64: remove duplicate ARCH_HAS_MEM_ENCRYPT arm64: mm: use untagged address to calculate page index arm64: mm: make linear mapping permission update more robust for patial range arm64/mm: Elide TLB flush in certain pte protection transitions arm64/mm: Rename try_pgd_pgtable_alloc_init_mm arm64/mm: Allow __create_pgd_mapping() to propagate pgtable_alloc() errors arm64: add unlikely hint to MTE async fault check in el0_svc_common arm64: acpi: add newline to deferred APEI warning arm64: entry: Clean out some indirection arm64/mm: Ensure PGD_SIZE is aligned to 64 bytes when PA_BITS = 52 arm64/mm: Drop cpu_set_[default|idmap]_tcr_t0sz() arm64: remove unused ARCH_PFN_OFFSET arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack arm64: Remove assertion on CONFIG_VMAP_STACK * for-next/kselftest: : arm64 kselftest patches kselftest/arm64: Align zt-test register dumps * for-next/efi-preempt: : arm64: Make EFI calls preemptible arm64/efi: Call EFI runtime services without disabling preemption arm64/efi: Move uaccess en/disable out of efi_set_pgd() arm64/efi: Drop efi_rt_lock spinlock from EFI arch wrapper arm64/fpsimd: Permit kernel mode NEON with IRQs off arm64/fpsimd: Don't warn when EFI execution context is preemptible efi/runtime-wrappers: Keep track of the efi_runtime_lock owner efi: Add missing static initializer for efi_mm::cpus_allowed_lock * for-next/assembler-macro: : arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in headers arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headers arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in uapi headers * for-next/typos: : Random typo/spelling fixes arm64: Fix double word in comments arm64: Fix typos and spelling errors in comments * for-next/sme-ptrace-disable: : Support disabling streaming mode via ptrace on SME only systems kselftest/arm64: Cover disabling streaming mode without SVE in fp-ptrace kselftst/arm64: Test NT_ARM_SVE FPSIMD format writes on non-SVE systems arm64/sme: Support disabling streaming mode via ptrace on SME only systems * for-next/local-tlbi-page-reused: : arm64, mm: avoid TLBI broadcast if page reused in write fault arm64, tlbflush: don't TLBI broadcast if page reused in write fault mm: add spurious fault fixing support for huge pmd * for-next/mpam: (34 commits) : Basic Arm MPAM driver (more to follow) MAINTAINERS: new entry for MPAM Driver arm_mpam: Add kunit tests for props_mismatch() arm_mpam: Add kunit test for bitmap reset arm_mpam: Add helper to reset saved mbwu state arm_mpam: Use long MBWU counters if supported arm_mpam: Probe for long/lwd mbwu counters arm_mpam: Consider overflow in bandwidth counter state arm_mpam: Track bandwidth counter state for power management arm_mpam: Add mpam_msmon_read() to read monitor value arm_mpam: Add helpers to allocate monitors arm_mpam: Probe and reset the rest of the features arm_mpam: Allow configuration to be applied and restored during cpu online arm_mpam: Use a static key to indicate when mpam is enabled arm_mpam: Register and enable IRQs arm_mpam: Extend reset logic to allow devices to be reset any time arm_mpam: Add a helper to touch an MSC from any CPU arm_mpam: Reset MSC controls from cpuhp callbacks arm_mpam: Merge supported features during mpam_enable() into mpam_class arm_mpam: Probe the hardware features resctrl supports arm_mpam: Add helpers for managing the locking around the mon_sel registers ... * for-next/acpi: : arm64 acpi updates ACPI: GTDT: Get rid of acpi_arch_timer_mem_init() * for-next/documentation: : arm64 Documentation updates Documentation/arm64: Fix the typo of register names 2025-11-27T18:16:46Z Ben Horgan ben.horgan@arm.com 2025-11-25T10:12:07Z urn:sha1:4138cc63d3efdd77de799aafb0bd183e1d655a0f In test_clidr() if an empty cache level is not found then the TEST_ASSERT will not fire. Fix this by considering all 7 possible levels when iterating through the hierarchy. Found by inspection. Signed-off-by: Ben Horgan <ben.horgan@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Oliver Upton <oupton@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2025-11-27T18:16:46Z Ben Horgan ben.horgan@arm.com 2025-11-25T10:12:06Z urn:sha1:bf09ee918053edec7efeb2f9977b53b02e029553 ARM64_FEATURE_FIELD_BITS is set to 4 but not all ID register fields are 4 bits. See for instance ID_AA64SMFR0_EL1. The last user of this define, ARM64_FEATURE_FIELD_BITS, is the set_id_regs selftest. Its logic assumes the fields aren't a single bits; assert that's the case and stop using the define. As there are no more users, ARM64_FEATURE_FIELD_BITS is removed from the arm64 tools sysreg.h header. A separate commit removes this from the kernel version of the header. Signed-off-by: Ben Horgan <ben.horgan@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Oliver Upton <oupton@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>