kernel/linux.git/arch/arm64/include/asm/processor.h, branch v6.6.132

locking: remove spin_lock_prefetch

2023-08-12T16:18:47+00:00

The only remaining consumer is new_inode, where it showed up in 2001 as commit c37fa164f793 ("v2.4.9.9 -> v2.4.9.10") in a historical repo [1] with a changelog which does not mention it. Since then the line got only touched up to keep compiling. While it may have been of benefit back in the day, it is guaranteed to at best not get in the way in the multicore setting -- as the code performs *a lot* of work between the prefetch and actual lock acquire, any contention means the cacheline is already invalid by the time the routine calls spin_lock(). It adds spurious traffic, for short. On top of it prefetch is notoriously tricky to use for single-threaded purposes, making it questionable from the get go. As such, remove it. I admit upfront I did not see value in benchmarking this change, but I can do it if that is deemed appropriate. Removal from new_inode and of the entire thing are in the same patch as requested by Linus, so whatever weird looks can be directed at that guy. Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/fs/inode.c?id=c37fa164f793735b32aa3f53154ff1a7659e6442 [1] Signed-off-by: Mateusz Guzik Signed-off-by: Linus Torvalds

arm64/sme: Rename za_state to sme_state

2023-01-20T12:23:05+00:00

In preparation for adding support for storage for ZT0 to the thread_struct rename za_state to sme_state. Since ZT0 is accessible when PSTATE.ZA is set just like ZA itself we will extend the allocation done for ZA to cover it, avoiding the need to further expand task_struct for non-SME tasks. No functional changes. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-1-f2fa0aef982f@kernel.org Signed-off-by: Catalin Marinas

Merge branch 'for-next/trivial' into for-next/core

2022-12-06T11:33:29+00:00

* for-next/trivial: arm64: alternatives: add __init/__initconst to some functions/variables arm64/asm: Remove unused assembler DAIF save/restore macros arm64/kpti: Move DAIF masking to C code Revert "arm64/mm: Drop redundant BUG_ON(!pgtable_alloc)" arm64/mm: Drop unused restore_ttbr1 arm64: alternatives: make apply_alternatives_vdso() static arm64/mm: Drop idmap_pg_end[] declaration arm64/mm: Drop redundant BUG_ON(!pgtable_alloc) arm64: make is_ttbrX_addr() noinstr-safe arm64/signal: Document our convention for choosing magic numbers arm64: atomics: lse: remove stale dependency on JUMP_LABEL arm64: paravirt: remove conduit check in has_pv_steal_clock arm64: entry: Fix typo arm64/booting: Add missing colon to FA64 entry arm64/mm: Drop ARM64_KERNEL_USES_PMD_MAPS arm64/asm: Remove unused enable_da macro

Merge branch 'for-next/sve-state' into for-next/core

2022-12-06T11:27:28+00:00

* for-next/sve-state: arm64/fp: Use a struct to pass data to fpsimd_bind_state_to_cpu() arm64/sve: Leave SVE enabled on syscall if we don't context switch arm64/fpsimd: SME no longer requires SVE register state arm64/fpsimd: Load FP state based on recorded data type arm64/fpsimd: Stop using TIF_SVE to manage register saving in KVM arm64/fpsimd: Have KVM explicitly say which FP registers to save arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE KVM: arm64: Discard any SVE state when entering KVM guests

arm64/fpsimd: Have KVM explicitly say which FP registers to save

2022-11-29T15:01:56+00:00

In order to avoid needlessly saving and restoring the guest registers KVM relies on the host FPSMID code to save the guest registers when we context switch away from the guest. This is done by binding the KVM guest state to the CPU on top of the task state that was originally there, then carefully managing the TIF_SVE flag for the task to cause the host to save the full SVE state when needed regardless of the needs of the host task. This works well enough but isn't terribly direct about what is going on and makes it much more complicated to try to optimise what we're doing with the SVE register state. Let's instead have KVM pass in the register state it wants saving when it binds to the CPU. We introduce a new FP_STATE_CURRENT for use during normal task binding to indicate that we should base our decisions on the current task. This should not be used when actually saving. Ideally we might want to use a separate enum for the type to save but this enum and the enum values would then need to be named which has problems with clarity and ambiguity. In order to ease any future debugging that might be required this patch does not actually update any of the decision making about what to save, it merely starts tracking the new information and warns if the requested state is not what we would otherwise have decided to save. Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20221115094640.112848-4-broonie@kernel.org Signed-off-by: Will Deacon

arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE

2022-11-29T15:01:56+00:00

When we save the state for the floating point registers this can be done in the form visible through either the FPSIMD V registers or the SVE Z and P registers. At present we track which format is currently used based on TIF_SVE and the SME streaming mode state but particularly in the SVE case this limits our options for optimising things, especially around syscalls. Introduce a new enum which we place together with saved floating point state in both thread_struct and the KVM guest state which explicitly states which format is active and keep it up to date when we change it. At present we do not use this state except to verify that it has the expected value when loading the state, future patches will introduce functional changes. Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20221115094640.112848-3-broonie@kernel.org Signed-off-by: Will Deacon

arm64: move on_thread_stack() to

2022-11-18T14:36:47+00:00

Currently on_thread_stack() is defined in , depending upon definitiong from despite this header not being included. This ends up being fragile, and any user of on_thread_stack() must include both and . We organised things this way due to header dependencies back in commit: 0b3e336601b82c6a ("arm64: Add support for STACKLEAK gcc plugin") ... but now that we no longer use current_top_of_stack(), and given that stackleak includes via , we no longer need the definition to live in . Move on_thread_stack() to , where all its dependencies are guaranteed to be defined. This requires having arm64's irq.c explicitly include , and I've taken the opportunity to sort the includes, which were slightly out of order. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Kees Cook Cc: Will Deacon Reviewed-by: Kees Cook Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20221117120902.3974163-3-mark.rutland@arm.com Signed-off-by: Will Deacon

arm64: remove current_top_of_stack()

2022-11-18T14:36:47+00:00

We no longer use current_top_of_stack() on arm64, so it can be removed. We introduced current_top_of_stack() for STACKLEAK in commit: 0b3e336601b82c6a ("arm64: Add support for STACKLEAK gcc plugin") ... then we figured out the intended semantics were unclear, and reworked it in commit: e85094c31ddb794a ("arm64: stackleak: fix current_top_of_stack()") ... then we removed the only user in commit: 0cfa2ccd285d98ad ("stackleak: rework stack high bound handling") Given that it's no longer used, and it's very easy to misuse, this patch removes current_top_of_stack(). For the moment, on_thread_stack() is left where it is as moving it will change some header dependencies. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Kees Cook Cc: Will Deacon Reviewed-by: Kees Cook Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20221117120902.3974163-2-mark.rutland@arm.com Signed-off-by: Will Deacon

arm64: make is_ttbrX_addr() noinstr-safe

2022-11-15T13:06:40+00:00

We use is_ttbr0_addr() in noinstr code, but as it's only marked as inline, it's theoretically possible for the compiler to place it out-of-line and instrument it, which would be problematic. Mark is_ttbr0_addr() as __always_inline such that that can safely be used from noinstr code. For consistency, do the same to is_ttbr1_addr(). Note that while is_ttbr1_addr() calls arch_kasan_reset_tag(), this is a macro (and its callees are either macros or __always_inline), so there is not a risk of transient instrumentation. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Link: https://lore.kernel.org/r/20221114144042.3001140-1-mark.rutland@arm.com Signed-off-by: Will Deacon

Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-10-12T18:00:22+00:00

Pull non-MM updates from Andrew Morton: - hfs and hfsplus kmap API modernization (Fabio Francesco) - make crash-kexec work properly when invoked from an NMI-time panic (Valentin Schneider) - ntfs bugfixes (Hawkins Jiawei) - improve IPC msg scalability by replacing atomic_t's with percpu counters (Jiebin Sun) - nilfs2 cleanups (Minghao Chi) - lots of other single patches all over the tree! * tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits) include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype proc: test how it holds up with mapping'less process mailmap: update Frank Rowand email address ia64: mca: use strscpy() is more robust and safer init/Kconfig: fix unmet direct dependencies ia64: update config files nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure fork: remove duplicate included header files init/main.c: remove unnecessary (void*) conversions proc: mark more files as permanent nilfs2: remove the unneeded result variable nilfs2: delete unnecessary checks before brelse() checkpatch: warn for non-standard fixes tag style usr/gen_init_cpio.c: remove unnecessary -1 values from int file ipc/msg: mitigate the lock contention with percpu counter percpu: add percpu_counter_add_local and percpu_counter_sub_local fs/ocfs2: fix repeated words in comments relay: use kvcalloc to alloc page array in relay_alloc_page_array proc: make config PROC_CHILDREN depend on PROC_FS fs: uninline inode_maybe_inc_iversion() ...