wireguard-linux/arch/arm/kernel/entry-armv.S, branch update-toolchain

ARM: 9404/1: arm32: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION

2024-06-10T11:01:33Z

The current arm32 architecture does not yet support the HAVE_LD_DEAD_CODE_DATA_ELIMINATION feature. arm32 is widely used in embedded scenarios, and enabling this feature would be beneficial for reducing the size of the kernel image. In order to make this work, we keep the necessary tables by annotating them with KEEP, also it requires further changes to linker script to KEEP some tables and wildcard compiler generated sections into the right place. When using ld.lld for linking, KEEP is not recognized within the OVERLAY command, and Ard proposed a concise method to solve this problem. It boots normally with defconfig, vexpress_defconfig and tinyconfig. The size comparison of zImage is as follows: defconfig vexpress_defconfig tinyconfig 5137712 5138024 424192 no dce 5032560 4997824 298384 dce 2.0% 2.7% 29.7% shrink When using smaller config file, there is a significant reduction in the size of the zImage. We also tested this patch on a commercially available single-board computer, and the comparison is as follows: a15eb_config 2161384 no dce 2092240 dce 3.2% shrink The zImage size has been reduced by approximately 3.2%, which is 70KB on 2.1M. Signed-off-by: Yuntao Liu Tested-by: Arnd Bergmann Reviewed-by: Arnd Bergmann Reviewed-by: Linus Walleij Signed-off-by: Russell King (Oracle)

Merge branch 'devel-stable' into for-next

2023-08-14T11:18:06Z

Merge tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2023-07-06T17:06:04Z

Pull asm-generic updates from Arnd Bergmann: "These are cleanups for architecture specific header files: - the comments in include/linux/syscalls.h have gone out of sync and are really pointless, so these get removed - The asm/bitsperlong.h header no longer needs to be architecture specific on modern compilers, so use a generic version for newer architectures that use new enough userspace compilers - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking, forcing the use of pointers" * tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: syscalls: Remove file path comments from headers tools arch: Remove uapi bitsperlong.h of hexagon and microblaze asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch m68k/mm: Make pfn accessors static inlines arm64: memory: Make virt_to_pfn() a static inline ARM: mm: Make virt_to_pfn() a static inline asm-generic/page.h: Make pfn accessors static inlines xen/netback: Pass (void *) to virt_to_page() netfs: Pass a pointer to virt_to_page() cifs: Pass a pointer to virt_to_page() in cifsglob cifs: Pass a pointer to virt_to_page() riscv: mm: init: Pass a pointer to virt_to_page() ARC: init: Pass a pointer to virt_to_pfn() in init m68k: Pass a pointer to virt_to_pfn() virt_to_page() fs/proc/kcore.c: Pass a pointer to virt_addr_valid()

arm: update in-source documentation references

2023-06-12T12:33:48Z

The Arm documentation has moved to Documentation/arch/arm; update references within arch/arm to match. Cc: Russell King Cc: Alim Akhtar Cc: Patrice Chotard Cc: linux-doc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Signed-off-by: Jonathan Corbet

ARM: mm: Make virt_to_pfn() a static inline

2023-05-29T09:27:08Z

Making virt_to_pfn() a static inline taking a strongly typed (const void *) makes the contract of a passing a pointer of that type to the function explicit and exposes any misuse of the macro virt_to_pfn() acting polymorphic and accepting many types such as (void *), (unitptr_t) or (unsigned long) as arguments without warnings. Doing this is a bit intrusive: virt_to_pfn() requires PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in , so this must be included *before* . The use of macros were obscuring the unclear inclusion order here, as the macros would eventually be resolved, but a static inline like this cannot be compiled with unresolved macros. The naive solution to include at the top of does not work, because sometimes includes at the end of itself, which would create a confusing inclusion loop. So instead, take the approach to always unconditionally include at the end of arch/arm uses explicitly in a lot of places, however it turns out that if we just unconditionally include into and switch all inclusions of to instead, we enforce the right order and will always have access to the definitions. Put an inclusion guard in place making it impossible to include explicitly. Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/ Signed-off-by: Linus Walleij

ARM: entry: Make asm coproc dispatch code NWFPE only

2023-05-17T13:08:22Z

Now that we can dispatch all VFP and iWMMXT related undef exceptions using undef hooks implemented in C code, we no longer need the asm entry code that takes care of this unless we are using FPE, so we can move it into the FPE entry code. As this means it is ARM only, we can remove the Thumb2 specific decorations as well. It also means the non-standard, asm-only calling convention where returning via LR means failure and returning via R9 means success is now only used on legacy platforms that lack any kind of function return prediction, avoiding the associated performance impact. Reviewed-by: Linus Walleij Signed-off-by: Ard Biesheuvel

ARM: iwmmxt: Use undef hook to enable coprocessor for task

2023-05-17T13:08:22Z

Define a undef hook to deal with undef exceptions triggered by iwmmxt instructions that were issued with the coprocessor disabled. This removes the dependency on the coprocessor dispatch code in entry-armv.S, which will be made NWFPE-only in a subsequent patch. Reviewed-by: Linus Walleij Signed-off-by: Ard Biesheuvel

ARM: entry: Disregard Thumb undef exception in coproc dispatch

2023-05-17T13:08:22Z

Now that the only remaining coprocessor instructions being handled via the dispatch in entry-armv.S are ones that only exist in a ARM (A32) encoding, we can simplify the handling of Thumb undef exceptions, and send them straight to the undefined instruction handlers in C code. This also means we can drop the code that partially decodes the instruction to decide whether it is a 16-bit or 32-bit Thumb instruction: this is all taken care of by the undef hook. Acked-by: Linus Walleij Signed-off-by: Ard Biesheuvel

ARM: vfp: Use undef hook for handling VFP exceptions

2023-05-17T13:08:22Z

Now that the VFP support code has been reimplemented as a C function that takes a struct pt_regs pointer and an opcode, we can use the existing undef_hook framework to deal with undef exceptions triggered by VFP instructions instead of having special handling in assembler. Reviewed-by: Linus Walleij Signed-off-by: Ard Biesheuvel

ARM: kernel: Get rid of thread_info::used_cp[] array

2023-05-17T13:08:22Z

We keep track of which coprocessor triggered a fault in the used_cp[] array in thread_info, but this data is never used anywhere. So let's remove it. Linus did some digging and found out that the last user of this field was removed in commit bb1a773d5b6b ("kill unused dump_fpu() instances"). Reviewed-by: Linus Walleij Signed-off-by: Ard Biesheuvel