kernel/git/stable/linux.git/arch/alpha/Kconfig, branch master

alpha: enable lockdep hardirq state tracking

2026-07-19T11:16:26+00:00

Alpha masks interrupts through the PAL IPL state, so lockdep cannot infer hardirq state transitions from generic code alone. Add explicit hardirq on/off annotations to the low-level entry and return paths so lockdep's IRQ state follows the hardware IPL state. Annotate the PAL IPL transitions and the shared return-to-user/kernel paths where interrupts become enabled or disabled. With the preceding irqflags, raw-lock, sysfs, and ftrace return-address preparations in place, select LOCKDEP_SUPPORT and TRACE_IRQFLAGS_SUPPORT for Alpha. This keeps CONFIG_PROVE_LOCKING usable on Alpha instead of disabling debug_locks due to IRQ-state mismatches. Reviewed-by: Matt Turner Tested-by: Matt Turner Signed-off-by: Magnus Lindholm Link: https://lore.kernel.org/r/20260706170019.2941459-7-linmag7@gmail.com Signed-off-by: Magnus Lindholm

alpha: add ARCH_STACKWALK-based stacktrace support

2026-07-19T11:15:54+00:00

Implement arch_stack_walk() for Alpha using a simple kernel stack scanning walker. Start from regs+1 for current tasks to skip pt_regs and use pcb.ksp for blocked tasks. Filter candidates with __kernel_text_address() and stop at stack bounds via kstack_end(). Enable CONFIG_STACKTRACE_SUPPORT and CONFIG_ARCH_STACKWALK so generic stacktrace users (dump_stack(), /proc/*/stack, SysRq backtraces, etc.) work on Alpha. This provides functional in-kernel stack traces without requiring frame pointer unwinding. Reviewed-by: Matt Turner Tested-by: Matt Turner Signed-off-by: Magnus Lindholm Link: https://lore.kernel.org/r/20260706170019.2941459-3-linmag7@gmail.com Signed-off-by: Magnus Lindholm

alpha: enable regset-based ptrace and core dumps

2026-07-19T11:15:40+00:00

Add a user_regset_view for Alpha and switch ELF core dumping to CORE_DUMP_USE_REGSET. General-purpose registers are exported in ELF gregs layout, including callee-saved registers and a correct user stack pointer. The user stack pointer is not preserved in pt_regs on Alpha, so expose it from the PCB, or via rdusp() for the current task, when building the ELF register image. This makes the user stack pointer consistent for core dumps, ptrace regsets, and PTRACE_GET_SYSCALL_INFO. Implement regset get/set callbacks for both NT_PRSTATUS and NT_PRFPREG. The callbacks translate between Alpha's pt_regs/thread state and the ELF-visible register layouts, while the common ptrace regset code handles PTRACE_GETREGSET and PTRACE_SETREGSET iovec semantics. This avoids duplicating subtle short-buffer and oversized-buffer behavior in arch_ptrace(). With these changes Alpha satisfies the requirements for HAVE_ARCH_TRACEHOOK and selects it, enabling generic tracehook and ptrace syscall-info code paths without changing the existing syscall entry ABI. Reviewed-by: Matt Turner Tested-by: Matt Turner Signed-off-by: Magnus Lindholm Link: https://lore.kernel.org/r/20260706170019.2941459-2-linmag7@gmail.com Signed-off-by: Magnus Lindholm

alpha: add support for SECCOMP and SECCOMP_FILTER

2026-04-12T17:13:59+00:00

Add SECCOMP and SECCOMP_FILTER support to the Alpha architecture and fix syscall entry and ptrace issues uncovered by the seccomp-bpf selftests. The syscall entry path is reworked to consistently track syscall state using r0, r1 and r2: - r1 holds the active syscall number - r2 preserves the original syscall number for restart - r0 carries the return value, with r19 (a3) indicating success/error This allows syscall restarts to be permitted only for valid ERESTART* return codes and prevents kernel-internal restart values from leaking to userspace. The syscall tracing error marker is corrected to use the saved syscall number slot, matching the Alpha ABI. Additionally, implement minimal PTRACE_GETREGSET and PTRACE_SETREGSET support for NT_PRSTATUS, exporting struct pt_regs directly. This fixes ptrace-based seccomp tests that previously failed with -EIO. With these changes, seccomp-bpf and ptrace syscall tests pass reliably on Alpha. Tested-by: Michael Cree Signed-off-by: Magnus Lindholm Link: https://lore.kernel.org/r/20260409171439.8759-2-linmag7@gmail.com Signed-off-by: Magnus Lindholm

alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE

2026-02-06T23:47:17+00:00

On a 64-bit system, madvise(MADV_DONTNEED) may cause a large number of empty PTE page table pages (such as 100GB+). To resolve this problem, first enable MMU_GATHER_RCU_TABLE_FREE to prepare for enabling the PT_RECLAIM feature, which resolves this problem. Link: https://lkml.kernel.org/r/3380f40a89b73c488202c85f9a8abf99fb08543b.1769515122.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: Magnus Lindholm [alpha] Cc: Richard Henderson Cc: Matt Turner Cc: Andreas Larsson Cc: "Aneesh Kumar K.V" Cc: Anton Ivanov Cc: Borislav Petkov Cc: Dave Hansen Cc: David Hildenbrand (Red Hat) Cc: Dev Jain Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Johannes Berg Cc: Lance Yang Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Richard Weinberger Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: WANG Xuerui Cc: Wei Yang Cc: Will Deacon Signed-off-by: Andrew Morton

mm/percpu: conditionally define _shared_alloc_tag via CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU

2025-07-10T05:42:15+00:00

Recently discovered this entry while checking kallsyms on ARM64: ffff800083e509c0 D _shared_alloc_tag If ARCH_NEEDS_WEAK_PER_CPU is not defined(it is only defined for s390 and alpha architectures), there's no need to statically define the percpu variable _shared_alloc_tag. Therefore, we need to implement isolation for this purpose. When building the core kernel code for s390 or alpha architectures, ARCH_NEEDS_WEAK_PER_CPU remains undefined (as it is gated by #if defined(MODULE)). However, when building modules for these architectures, the macro is explicitly defined. Therefore, we remove all instances of ARCH_NEEDS_WEAK_PER_CPU from the code and introduced CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU to replace the relevant logic. We can now conditionally define the perpcu variable _shared_alloc_tag based on CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU. This allows architectures (such as s390/alpha) that require weak definitions for percpu variables in modules to include the definition, while others can omit it via compile-time exclusion. Link: https://lkml.kernel.org/r/20250618015809.1235761-1-hao.ge@linux.dev Signed-off-by: Hao Ge Suggested-by: Suren Baghdasaryan Acked-by: Alexander Gordeev [s390] Acked-by: Mike Rapoport (Microsoft) Cc: Chistoph Lameter Cc: Christian Borntraeger Cc: David Hildenbrand Cc: Dennis Zhou Cc: Heiko Carstens Cc: Kent Overstreet Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Matt Turner Cc: Richard Henderson Cc: Sven Schnelle Cc: Tejun Heo Cc: Vasily Gorbik Cc: Vlastimil Babka Signed-off-by: Andrew Morton

dma-mapping: clearly mark DMA ops as an architecture feature

2024-09-04T04:08:51+00:00

DMA ops are a helper for architectures and not for drivers to override the DMA implementation. Unfortunately driver authors keep ignoring this. Make the fact more clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers overriding their dma_ops depend on that. These drivers should probably be marked broken, but we can give them a bit of a grace period for that. Signed-off-by: Christoph Hellwig Reviewed-by: Thomas Gleixner Acked-by: Sakari Ailus # for IPU6 Acked-by: Robin Murphy

alpha: drop pre-EV56 support

2024-05-06T10:05:00+00:00

All EV4 machines are already gone, and the remaining EV5 based machines all support the slightly more modern EV56 generation as well. Debian only supports EV56 and later. Drop both of these and build kernels optimized for EV56 and higher when the "generic" options is selected, tuning for an out-of-order EV6 pipeline, same as Debian userspace. Since this was the only supported architecture without 8-bit and 16-bit stores, common kernel code no longer has to worry about aligning struct members, and existing workarounds from the block and tty layers can be removed. The alpha memory management code no longer needs an abstraction for the differences between EV4 and EV5+. Link: https://lists.debian.org/debian-alpha/2023/05/msg00009.html Acked-by: Paul E. McKenney Acked-by: Matt Turner Signed-off-by: Arnd Bergmann

alpha: cabriolet: remove EV5 CPU support

2024-05-03T20:10:03+00:00

The sys_cabriolet.c file includes support for multiple evaluation boards. pc164 and lx164 are for ev56 CPUs, while the eb164 is now the last supported machine that only supports ev5 but not ev56. Acked-by: Paul E. McKenney Acked-by: Matt Turner Signed-off-by: Arnd Bergmann

alpha: remove LCA and APECS based machines

2024-05-03T20:09:59+00:00

APECS is the DECchip 21071x chipset for the EV4 and EV45 generation, while LCA is the integrated I/O support on the corresponding low-cost alpha machines of that generation. All of these CPUs lack the BWX extension for byte and word access, so drop the chipset support and all associated machines. Acked-by: Paul E. McKenney Acked-by: Matt Turner Signed-off-by: Arnd Bergmann