[PATCH 5/8] drm/panthor: Minor scheduler refactoring

Ketil Johnsen
2026-05-05T14:05:52Z

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>
---
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);
}
}
--
2.43.0