On 13.02.2026 17:28, Oleksii Kurochko wrote:
> Introduce a function pointer for sbi_set_timer(), since different OpenSBI
> versions may implement the TIME extension with different extension IDs
> and/or function IDs.
>
> If the TIME extension is not available, fall back to the legacy timer
> mechanism. This is useful when Xen runs as a guest under another Xen,
> because the TIME extension is not currently virtualised and therefore
> will not appear as available.
> Despite of the fact that sbi_set_timer_v01 is introduced and used as
> fall back, SBI v0.1 still isn't fully supported (with the current SBI
> calls usage, sbi_rfence_v01 should be introduced too), so panic()
> in sbi_init() isn't removed.
>
> The sbi_set_timer() pointer will be used by reprogram_timer() to program
> Xen’s physical timer as without SSTC extension there is no any other
> option except SBI call to do that as only M-timer is available for us.
>
> Use dprintk() for all the cases to print that a speicifc SBI extension
> is available as it isn't really necessary in case of release builds.
>
> Signed-off-by: Oleksii Kurochko <[email protected]>
> Acked-by: Jan Beulich <[email protected]>
> ---
> Changes in v4:
> - Add "stime_value is in absolute time" to the comment above declaration
> of sbi_set_timer() function pointer.
Yet it still ...
> @@ -134,6 +138,23 @@ int sbi_remote_hfence_gvma(const cpumask_t *cpu_mask,
> vaddr_t start,
> int sbi_remote_hfence_gvma_vmid(const cpumask_t *cpu_mask, vaddr_t start,
> size_t size, unsigned long vmid);
>
> +/*
> + * Programs the clock for next event after stime_value time. stime_value is
> in
> + * absolute time. This function must clear the pending timer interrupt bit as
> + * well.
... says "after" when, as per my understanding, it's "at or after". At which
point the final "time" in the sentence becomes bogus (says me as a non-
native speaker). Which in turn is what my v3 comment was triggered by, as
"after stime_value time" to me suggests something relative ("this amount of
time needs to pass"), when that's not what is meant, as the added sentence
now tries to clarify.
Jan
