On Thu, Aug 22, 2024 at 02:15:24AM +0100, Mark Brown wrote: > @@ -512,10 +538,16 @@ static void gcs_thread_switch(struct task_struct *next) > gcs_set_el0_mode(next); > > /* > - * Ensure that GCS changes are observable by/from other PEs in > - * case of migration. > + * Ensure that GCS memory effects of the 'prev' thread are > + * ordered before other memory accesses with release semantics > + * (or preceded by a DMB) on the current PE. In addition, any > + * memory accesses with acquire semantics (or succeeded by a > + * DMB) are ordered before GCS memory effects of the 'next' > + * thread. This will ensure that the GCS memory effects are > + * visible to other PEs in case of migration. > */ > - gcsb_dsync(); > + if (task_gcs_el0_enabled(current) || task_gcs_el0_enabled(next)) > + gcsb_dsync(); > } Ah, the comment turned up in this patch. It looks fine. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
