Re: [PATCH v3 0/4] sparc64: D-cache alias flushing fixes

[Andreas Larsson]

On 2026-10-22 01:33, Imre Kaloz wrote:
> These fix D-cache alias flushing on sparc64 CPUs with a virtually
> indexed L1 D-cache (Spitfire and Cheetah).
> 
> 1/4 makes xcall_deliver() bail out before it touches the trap block
> when there is no other CPU to call, so an early cross call, before
> init_IRQ() sets up the mondo blocks, can't end up writing to physical
> address 0.
> 
> 2/4 flushes only the page a PTE maps instead of its whole folio, which
> removes about a million redundant page flushes from a colour-changing
> mremap() of a large folio (7.3 s on a Sun Fire V240).
> 
> 3/4 implements flush_cache_vmap() and flush_cache_vunmap(), which have
> been no-ops. Stale vmalloc lines corrupt BPF programs and module data
> on UltraSPARC III.
> 
> 4/4 passes the number of PTEs to move_pte(), as Andreas suggested. It
> touches mm/mremap.c and include/linux/pgtable.h, so it needs an ack
> from the mm folks.
> 
> 1-3 don't depend on 4 and can go in on their own. 2 and 3 are for
> stable (3 needs 2), 1 and 4 aren't. The series is on top of the sparc
> for-next branch.
> 
> Changes in v3:
> - new 1/4 and 4/4, following Andreas' review
> - 2/4: reworded the message and the move_pte() comment, marked the
>   UP #endif
> - 3/4: reworded the message, dropped the Suggested-by (I have no
>   email address for nsafran1217, the Link credits them), noted the
>   stable dependency on 2/4
> - picked up Stian's and Adrian's Tested-by tags
> 
> v2: https://lore.kernel.org/r/20260928132102.1707-1-kaloz@xxxxxxxxxx
> 
> Imre Kaloz (4):
>   sparc64: skip the trap block in xcall_deliver() when there is no
>     target
>   sparc64: flush only the aliased page, not its whole folio
>   sparc64: flush vmalloc ranges from the D-cache on map and unmap
>   mm: pass the number of PTEs to move_pte()
> 
>  arch/sparc/include/asm/cacheflush_64.h |  9 ++--
>  arch/sparc/include/asm/pgtable_64.h    | 14 ++++--
>  arch/sparc/kernel/smp_64.c             | 51 +++++++++++++++-----
>  arch/sparc/mm/init_64.c                | 65 ++++++++++++++++++++++++++
>  arch/sparc/mm/tlb.c                    |  2 +-
>  arch/sparc/mm/ultra.S                  | 25 ++++++++++
>  include/linux/pgtable.h                |  2 +-
>  mm/mremap.c                            |  2 +-
>  8 files changed, 148 insertions(+), 22 deletions(-)
> 
> 
> base-commit: 2bc58762a3d74e42de129d717ae3ba10ecf0ab96

Reviewed-by: Andreas Larsson <andreas@xxxxxxxxxxx>

Picking patches 1-3 to my for-next. I won't pick number 4 up at this
point without confirmation from the mm folks.

Thanks,
Andreas