[PATCH v3] drm/xe/xe_guc_ads: save/restore OA registers

[Lucas De Marchi]

On Tue, Oct 29, 2024 at 10:15:54AM -0700, Ashutosh Dixit wrote:
>On Tue, 29 Oct 2024 09:23:49 -0700, Lucas De Marchi wrote:
>>
>> On Wed, Oct 23, 2024 at 08:07:15PM +0000, Jonathan Cavitt wrote:
>> > Several OA registers and allowlist registers were missing from the
>> > save/restore list for GuC and could be lost during an engine reset.  Add
>> > them to the list.
>> >
>> > v2:
>> > - Fix commit message (Umesh)
>> > - Add missing closes (Ashutosh)
>> >
>> > v3:
>> > - Add missing fixes (Ashutosh)
>> >
>> > Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2249
>> > Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
>> > Suggested-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>> > Suggested-by: John Harrison <john.c.harrison at intel.com>
>> > Signed-off-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
>> > CC: stable at vger.kernel.org # v6.11+
>> > Acked-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
>> > Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
>> > ---
>> > drivers/gpu/drm/xe/xe_guc_ads.c | 14 ++++++++++++++
>> > 1 file changed, 14 insertions(+)
>> >
>> > diff --git a/drivers/gpu/drm/xe/xe_guc_ads.c b/drivers/gpu/drm/xe/xe_guc_ads.c
>> > index 4e746ae98888..a196c4fb90fc 100644
>> > --- a/drivers/gpu/drm/xe/xe_guc_ads.c
>> > +++ b/drivers/gpu/drm/xe/xe_guc_ads.c
>> > @@ -15,6 +15,7 @@
>> > #include "regs/xe_engine_regs.h"
>> > #include "regs/xe_gt_regs.h"
>> > #include "regs/xe_guc_regs.h"
>> > +#include "regs/xe_oa_regs.h"
>> > #include "xe_bo.h"
>> > #include "xe_gt.h"
>> > #include "xe_gt_ccs_mode.h"
>> > @@ -740,6 +741,11 @@ static unsigned int guc_mmio_regset_write(struct xe_guc_ads *ads,
>> >		guc_mmio_regset_write_one(ads, regset_map, e->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++);
>>
>> this is not the proper place. See drivers/gpu/drm/xe/xe_reg_whitelist.c.
>
>Yikes, this got merged yesterday.
>
>>
>> The loop just before these added lines should be sufficient to go over
>> all engine save/restore register and give them to guc.
>
>You probably mean this one?
>
>	xa_for_each(&hwe->reg_sr.xa, idx, entry)
>		guc_mmio_regset_write_one(ads, regset_map, entry->reg, count++);
>
>But then how come this patch fixed GL #2249?

it fixes, it just doesn't put it in the right place according to the
driver arch. Whitelists should be in that other file so it shows up in
debugfs, (/sys/kernel/debug/dri/*/*/register-save-restore), detect
clashes when we try to add the same register, etc.


Lucas De Marchi

>
>Ashutosh