Re: [PATCH v3] drm/xe/xe_guc_ads: Add nonpriv registers to write list

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Fri, 22 Nov 2024 10:08:26 -0800, Jonathan Cavitt wrote:
>
> When performing a guc_mmio_regset_write, we add all the registers in the
> reg_sr list to the save/restore list, but do not do the same for the
> nonpriv registers.  Add them in.
>
> v2:
> - Add all NONPRIV registers to avoid undefined behavior (Harrison)
> - s/whitelist/nonpriv
>
> v3:
> - Rebase
>
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/issues/2249
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> CC: Lucas de Marchi <lucas.demarchi@intel.com>
> CC: Matt Roper <matthew.d.roper@intel.com>
> CC: John Harrison <john.c.harrison@intel.com>
> CC: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> CC: Ashutosh Dixit <ashutosh.dixit@intel.com>
> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_ads.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
> index 943146e5b460..b0afb89d9d90 100644
> --- a/drivers/gpu/drm/xe/xe_guc_ads.c
> +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
> @@ -243,6 +243,8 @@ static size_t calculate_regset_size(struct xe_gt *gt)
>		xa_for_each(&hwe->reg_sr.xa, sr_idx, sr_entry)
>			count++;
>
> +	count += RING_MAX_NONPRIV_SLOTS * XE_NUM_HW_ENGINES;
> +
>	count += ADS_REGSET_EXTRA_MAX * XE_NUM_HW_ENGINES;
>
>	if (XE_WA(gt, 1607983814))
> @@ -727,6 +729,11 @@ static unsigned int guc_mmio_regset_write(struct xe_guc_ads *ads,
>	xa_for_each(&hwe->reg_sr.xa, idx, entry)
>		guc_mmio_regset_write_one(ads, regset_map, entry->reg, count++);
>
> +	for (i = 0; i < RING_MAX_NONPRIV_SLOTS; i++)
> +		guc_mmio_regset_write_one(ads, regset_map,
> +					  RING_FORCE_TO_NONPRIV(hwe->mmio_base, i),
> +					  count++);
> +

What about the EU_PERF_CNTL registers which were there in the original
patch? Those are not needed?

>	for (e = extra_regs; e < extra_regs + ARRAY_SIZE(extra_regs); e++) {
>		if (e->skip)
>			continue;
> --
> 2.43.0
>