Re: [PATCH v1 02/13] arm64: mm: Introduce a C wrapper for by-range TLB invalidation

Linu Cherian
2026-01-05T05:33:39Z

Ryan,

On Tue, Dec 16, 2025 at 02:45:47PM +0000, Ryan Roberts wrote:
> As part of efforts to reduce our reliance on complex preprocessor macros
> for TLB invalidation routines, introduce a new C wrapper for by-range
> TLB invalidation which can be used instead of the __tlbi() macro and can
> additionally be called from C code.
>
> Each specific tlbi range op is implemented as a C function and the
> appropriate function pointer is passed to __tlbi_range(). Since
> everything is declared inline and is statically resolvable, the compiler
> will convert the indirect function call to a direct inline execution.
>
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
> arch/arm64/include/asm/tlbflush.h | 33 ++++++++++++++++++++++++++++++-
> 1 file changed, 32 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
> index 13a59cf28943..c5111d2afc66 100644
> --- a/arch/arm64/include/asm/tlbflush.h
> +++ b/arch/arm64/include/asm/tlbflush.h
> @@ -459,6 +459,37 @@ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
> * operations can only span an even number of pages. We save this for last to
> * ensure 64KB start alignment is maintained for the LPA2 case.
> */
> +static __always_inline void rvae1is(u64 arg)
> +{
> + __tlbi(rvae1is, arg);
> +}
> +
> +static __always_inline void rvale1(u64 arg)
> +{
> + __tlbi(rvale1, arg);
> + __tlbi_user(rvale1, arg);

Should this __tlbi_user be added as part of patch 3 ?

> +}
> +
> +static __always_inline void rvale1is(u64 arg)
> +{
> + __tlbi(rvale1is, arg);
> +}
> +
> +static __always_inline void rvaale1is(u64 arg)
> +{
> + __tlbi(rvaale1is, arg);
> +}
> +
> +static __always_inline void ripas2e1is(u64 arg)
> +{
> + __tlbi(ripas2e1is, arg);
> +}
> +
> +static __always_inline void __tlbi_range(tlbi_op op, u64 arg)
> +{
> + op(arg);
> +}
> +
> #define __flush_tlb_range_op(op, start, pages, stride, \
> asid, tlb_level, tlbi_user, lpa2) \
> do { \
> @@ -486,7 +517,7 @@ do { \
> if (num >= 0) { \
> addr = __TLBI_VADDR_RANGE(__flush_start >> shift, asid, \
> scale, num, tlb_level); \
> - __tlbi(r##op, addr); \
> + __tlbi_range(r##op, addr); \
> if (tlbi_user) \
> __tlbi_user(r##op, addr); \
> __flush_start += __TLBI_RANGE_PAGES(num, scale) << PAGE_SHIFT; \
> --
> 2.43.0
>