[Linaro-mm-sig] Re: [PATCH 5/8] drm/panthor: Minor scheduler refactoring

On Tue, 5 May 2026 16:05:11 +0200 Ketil Johnsen ketil.johnsen@arm.com wrote:

From: Florent Tomasin florent.tomasin@arm.com

Refactor parts of the group scheduling logic into new helper functions. This will simplify addition of the protected mode feature.

Remove redundant assignments of csg_slot.

Signed-off-by: Florent Tomasin florent.tomasin@arm.com Co-developed-by: Ketil Johnsen ketil.johnsen@arm.com Signed-off-by: Ketil Johnsen ketil.johnsen@arm.com

Glad to see this big tick_ctx_apply() function split into smaller pieces.

Reviewed-by: Boris Brezillon boris.brezillon@collabora.com

---

drivers/gpu/drm/panthor/panthor_sched.c | 135 +++++++++++++++--------- 1 file changed, 86 insertions(+), 49 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c index 5ee386338005c..987072bd867c4 100644 --- a/drivers/gpu/drm/panthor/panthor_sched.c +++ b/drivers/gpu/drm/panthor/panthor_sched.c @@ -1934,6 +1934,12 @@ static void csgs_upd_ctx_init(struct panthor_csg_slots_upd_ctx *ctx) memset(ctx, 0, sizeof(*ctx)); } +static void csgs_upd_ctx_ring_doorbell(struct panthor_csg_slots_upd_ctx *ctx,

• 		       u32 csg_id)
  

+{

• ctx->update_mask |= BIT(csg_id);

+}

static void csgs_upd_ctx_queue_reqs(struct panthor_device *ptdev, struct panthor_csg_slots_upd_ctx *ctx, u32 csg_id, u32 value, u32 mask) @@ -1944,7 +1950,8 @@ static void csgs_upd_ctx_queue_reqs(struct panthor_device *ptdev, ctx->requests[csg_id].value = (ctx->requests[csg_id].value & ~mask) | (value & mask); ctx->requests[csg_id].mask |= mask;

• ctx->update_mask |= BIT(csg_id);

• csgs_upd_ctx_ring_doorbell(ctx, csg_id);

} static int csgs_upd_ctx_apply_locked(struct panthor_device *ptdev, @@ -1961,8 +1968,12 @@ static int csgs_upd_ctx_apply_locked(struct panthor_device *ptdev, while (update_slots) { struct panthor_fw_csg_iface *csg_iface; u32 csg_id = ffs(update_slots) - 1;

• u32 req_mask = ctx->requests[csg_id].mask;
  

update_slots &= ~BIT(csg_id);

• if (!req_mask)
  

• 	continue;
  

• csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id); panthor_fw_update_reqs(csg_iface, req, ctx->requests[csg_id].value,

@@ -1979,6 +1990,9 @@ static int csgs_upd_ctx_apply_locked(struct panthor_device *ptdev, int ret; update_slots &= ~BIT(csg_id);

• if (!req_mask)
  

• 	continue;
  

• csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);

ret = panthor_fw_csg_wait_acks(ptdev, csg_id, req_mask, &acked, 100); @@ -2266,12 +2280,76 @@ tick_ctx_cleanup(struct panthor_scheduler *sched, } } +static void +tick_ctx_evict_group(struct panthor_scheduler *sched,

•      struct panthor_csg_slots_upd_ctx *upd_ctx,
  

•      struct panthor_group *group)
  

+{

• struct panthor_device *ptdev = sched->ptdev;
• if (drm_WARN_ON(&ptdev->base, group->csg_id < 0))

• return;
  

• csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, group->csg_id,

• 		group_can_run(group) ?
  

• 		CSG_STATE_SUSPEND : CSG_STATE_TERMINATE,
  

• 		CSG_STATE_MASK);
  

+}

+static void +tick_ctx_reschedule_group(struct panthor_scheduler *sched,

• 	  struct panthor_csg_slots_upd_ctx *upd_ctx,
  

• 	  struct panthor_group *group,
  

• 	  int new_csg_prio)
  

+{

• struct panthor_device *ptdev = sched->ptdev;
• struct panthor_fw_csg_iface *csg_iface;
• struct panthor_csg_slot *csg_slot;
• if (group->csg_id < 0)

• return;
  

• csg_iface = panthor_fw_get_csg_iface(ptdev, group->csg_id);
• csg_slot = &sched->csg_slots[group->csg_id];
• if (csg_slot->priority != new_csg_prio) {

• panthor_fw_update_reqs(csg_iface, endpoint_req,
  

• 		       CSG_EP_REQ_PRIORITY(new_csg_prio),
  

• 		       CSG_EP_REQ_PRIORITY_MASK);
  

• csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, group->csg_id,
  

• 			csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
  

• 			CSG_ENDPOINT_CONFIG);
  

• }

+}

+static void +tick_ctx_schedule_group(struct panthor_scheduler *sched,

• 	struct panthor_sched_tick_ctx *ctx,
  

• 	struct panthor_csg_slots_upd_ctx *upd_ctx,
  

• 	struct panthor_group *group,
  

• 	int csg_id, int csg_prio)
  

+{

• struct panthor_device *ptdev = sched->ptdev;
• struct panthor_fw_csg_iface *csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
• group_bind_locked(group, csg_id);
• csg_slot_prog_locked(ptdev, csg_id, csg_prio);
• csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, csg_id,

• 		group->state == PANTHOR_CS_GROUP_SUSPENDED ?
  

• 		CSG_STATE_RESUME : CSG_STATE_START,
  

• 		CSG_STATE_MASK);
  

• csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, csg_id,

• 		csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
  

• 		CSG_ENDPOINT_CONFIG);
  

+}

static void tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *ctx) { struct panthor_group *group, *tmp; struct panthor_device *ptdev = sched->ptdev;

• struct panthor_csg_slot *csg_slot; int prio, new_csg_prio = MAX_CSG_PRIO, i; u32 free_csg_slots = 0; struct panthor_csg_slots_upd_ctx upd_ctx;

@@ -2282,42 +2360,12 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) { /* Suspend or terminate evicted groups. */ list_for_each_entry(group, &ctx->old_groups[prio], run_node) {

• 	bool term = !group_can_run(group);
  

• 	int csg_id = group->csg_id;
  

• 	if (drm_WARN_ON(&ptdev->base, csg_id < 0))
  

• 		continue;
  

• 	csg_slot = &sched->csg_slots[csg_id];
  

• 	csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
  

• 				term ? CSG_STATE_TERMINATE : CSG_STATE_SUSPEND,
  

• 				CSG_STATE_MASK);
  

• 	tick_ctx_evict_group(sched, &upd_ctx, group);
  

  }

/* Update priorities on already running groups. */ list_for_each_entry(group, &ctx->groups[prio], run_node) {

• 	struct panthor_fw_csg_iface *csg_iface;
  

• 	int csg_id = group->csg_id;
  

• 	if (csg_id < 0) {
  

• 		new_csg_prio--;
  

• 		continue;
  

• 	}
  

• 	csg_slot = &sched->csg_slots[csg_id];
  

• 	csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
  

• 	if (csg_slot->priority == new_csg_prio) {
  

• 		new_csg_prio--;
  

• 		continue;
  

• 	}
  

• 	panthor_fw_csg_endpoint_req_update(ptdev, csg_iface,
  

• 					   CSG_EP_REQ_PRIORITY(new_csg_prio),
  

• 					   CSG_EP_REQ_PRIORITY_MASK);
  

• 	csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
  

• 				csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
  

• 				CSG_ENDPOINT_CONFIG);
  

• 	new_csg_prio--;
  

• 	tick_ctx_reschedule_group(sched, &upd_ctx, group, new_csg_prio--);
  

  } }

@@ -2354,28 +2402,17 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) { list_for_each_entry(group, &ctx->groups[prio], run_node) { int csg_id = group->csg_id;

• 	struct panthor_fw_csg_iface *csg_iface;
  

• 	int csg_prio = new_csg_prio--;
  

• 	if (csg_id >= 0) {
  

• 		new_csg_prio--;
  

• 	if (csg_id >= 0)
  	continue;
  

• 	}
  

csg_id = ffs(free_csg_slots) - 1; if (drm_WARN_ON(&ptdev->base, csg_id < 0)) break;

• 	csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
  

• 	csg_slot = &sched->csg_slots[csg_id];
  

• 	group_bind_locked(group, csg_id);
  

• 	csg_slot_prog_locked(ptdev, csg_id, new_csg_prio--);
  

• 	csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
  

• 				group->state == PANTHOR_CS_GROUP_SUSPENDED ?
  

• 				CSG_STATE_RESUME : CSG_STATE_START,
  

• 				CSG_STATE_MASK);
  

• 	csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
  

• 				csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
  

• 				CSG_ENDPOINT_CONFIG);
  

• 	tick_ctx_schedule_group(sched, ctx, &upd_ctx, group, csg_id, csg_prio);
  

• free_csg_slots &= ~BIT(csg_id);
  

  } }