With GuC scheduling, it isn't safe to unpin a context while scheduling is enabled for that context as the GuC may touch some of the pinned state (e.g. LRC). To ensure scheduling isn't enabled when an unpin is done, a call back is added to intel_context_unpin when pin count == 1 to disable scheduling for that context. When the response CTB is received it is safe to do the final unpin.
Future patches may add a heuristic / delay to schedule the disable call back to avoid thrashing on schedule enable / disable.
Cc: John Harrison john.c.harrison@intel.com Signed-off-by: Matthew Brost matthew.brost@intel.com Reviewed-by: John Harrison John.C.Harrison@Intel.com --- drivers/gpu/drm/i915/gt/intel_context.c | 4 +- drivers/gpu/drm/i915/gt/intel_context.h | 27 +++- drivers/gpu/drm/i915/gt/intel_context_types.h | 2 + drivers/gpu/drm/i915/gt/uc/intel_guc.h | 2 + drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c | 3 + .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 147 +++++++++++++++++- 6 files changed, 181 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index ad7197c5910f..3d5b4116617f 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -306,9 +306,9 @@ int __intel_context_do_pin(struct intel_context *ce) return err; }
-void intel_context_unpin(struct intel_context *ce) +void __intel_context_do_unpin(struct intel_context *ce, int sub) { - if (!atomic_dec_and_test(&ce->pin_count)) + if (!atomic_sub_and_test(sub, &ce->pin_count)) return;
CE_TRACE(ce, "unpin\n"); diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h index b10cbe8fee99..974ef85320c2 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.h +++ b/drivers/gpu/drm/i915/gt/intel_context.h @@ -113,7 +113,32 @@ static inline void __intel_context_pin(struct intel_context *ce) atomic_inc(&ce->pin_count); }
-void intel_context_unpin(struct intel_context *ce); +void __intel_context_do_unpin(struct intel_context *ce, int sub); + +static inline void intel_context_sched_disable_unpin(struct intel_context *ce) +{ + __intel_context_do_unpin(ce, 2); +} + +static inline void intel_context_unpin(struct intel_context *ce) +{ + if (!ce->ops->sched_disable) { + __intel_context_do_unpin(ce, 1); + } else { + /* + * Move ownership of this pin to the scheduling disable which is + * an async operation. When that operation completes the above + * intel_context_sched_disable_unpin is called potentially + * unpinning the context. + */ + while (!atomic_add_unless(&ce->pin_count, -1, 1)) { + if (atomic_cmpxchg(&ce->pin_count, 1, 2) == 1) { + ce->ops->sched_disable(ce); + break; + } + } + } +}
void intel_context_enter_engine(struct intel_context *ce); void intel_context_exit_engine(struct intel_context *ce); diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h index e0e3a937f709..4a5518d295c2 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -43,6 +43,8 @@ struct intel_context_ops { void (*enter)(struct intel_context *ce); void (*exit)(struct intel_context *ce);
+ void (*sched_disable)(struct intel_context *ce); + void (*reset)(struct intel_context *ce); void (*destroy)(struct kref *kref); }; diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h index 30773cd699f5..03b7222b04a2 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h @@ -241,6 +241,8 @@ int intel_guc_reset_engine(struct intel_guc *guc,
int intel_guc_deregister_done_process_msg(struct intel_guc *guc, const u32 *msg, u32 len); +int intel_guc_sched_done_process_msg(struct intel_guc *guc, + const u32 *msg, u32 len);
void intel_guc_load_status(struct intel_guc *guc, struct drm_printer *p);
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c index 28ff82c5be45..019b25ff1888 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_ct.c @@ -932,6 +932,9 @@ static int ct_process_request(struct intel_guc_ct *ct, struct ct_incoming_msg *r ret = intel_guc_deregister_done_process_msg(guc, payload, len); break; + case INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_DONE: + ret = intel_guc_sched_done_process_msg(guc, payload, len); + break; default: ret = -EOPNOTSUPP; break; diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index a438aecfe93f..5519c988a6ca 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -70,6 +70,7 @@ * possible for some of the bits to changing at the same time though. */ #define SCHED_STATE_NO_LOCK_ENABLED BIT(0) +#define SCHED_STATE_NO_LOCK_PENDING_ENABLE BIT(1) static inline bool context_enabled(struct intel_context *ce) { return (atomic_read(&ce->guc_sched_state_no_lock) & @@ -87,6 +88,24 @@ static inline void clr_context_enabled(struct intel_context *ce) &ce->guc_sched_state_no_lock); }
+static inline bool context_pending_enable(struct intel_context *ce) +{ + return (atomic_read(&ce->guc_sched_state_no_lock) & + SCHED_STATE_NO_LOCK_PENDING_ENABLE); +} + +static inline void set_context_pending_enable(struct intel_context *ce) +{ + atomic_or(SCHED_STATE_NO_LOCK_PENDING_ENABLE, + &ce->guc_sched_state_no_lock); +} + +static inline void clr_context_pending_enable(struct intel_context *ce) +{ + atomic_and((u32)~SCHED_STATE_NO_LOCK_PENDING_ENABLE, + &ce->guc_sched_state_no_lock); +} + /* * Below is a set of functions which control the GuC scheduling state which * require a lock, aside from the special case where the functions are called @@ -95,6 +114,7 @@ static inline void clr_context_enabled(struct intel_context *ce) */ #define SCHED_STATE_WAIT_FOR_DEREGISTER_TO_REGISTER BIT(0) #define SCHED_STATE_DESTROYED BIT(1) +#define SCHED_STATE_PENDING_DISABLE BIT(2) static inline void init_sched_state(struct intel_context *ce) { /* Only should be called from guc_lrc_desc_pin() */ @@ -139,6 +159,24 @@ set_context_destroyed(struct intel_context *ce) ce->guc_state.sched_state |= SCHED_STATE_DESTROYED; }
+static inline bool context_pending_disable(struct intel_context *ce) +{ + return (ce->guc_state.sched_state & SCHED_STATE_PENDING_DISABLE); +} + +static inline void set_context_pending_disable(struct intel_context *ce) +{ + lockdep_assert_held(&ce->guc_state.lock); + ce->guc_state.sched_state |= SCHED_STATE_PENDING_DISABLE; +} + +static inline void clr_context_pending_disable(struct intel_context *ce) +{ + lockdep_assert_held(&ce->guc_state.lock); + ce->guc_state.sched_state = + (ce->guc_state.sched_state & ~SCHED_STATE_PENDING_DISABLE); +} + static inline bool context_guc_id_invalid(struct intel_context *ce) { return (ce->guc_id == GUC_INVALID_LRC_ID); @@ -231,6 +269,8 @@ static int guc_add_request(struct intel_guc *guc, struct i915_request *rq) action[len++] = INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET; action[len++] = ce->guc_id; action[len++] = GUC_CONTEXT_ENABLE; + set_context_pending_enable(ce); + intel_context_get(ce); } else { action[len++] = INTEL_GUC_ACTION_SCHED_CONTEXT; action[len++] = ce->guc_id; @@ -238,8 +278,12 @@ static int guc_add_request(struct intel_guc *guc, struct i915_request *rq)
err = intel_guc_send_nb(guc, action, len);
- if (!enabled && !err) + if (!enabled && !err) { set_context_enabled(ce); + } else if (!enabled) { + clr_context_pending_enable(ce); + intel_context_put(ce); + }
return err; } @@ -833,6 +877,62 @@ static void guc_context_post_unpin(struct intel_context *ce) lrc_post_unpin(ce); }
+static void __guc_context_sched_disable(struct intel_guc *guc, + struct intel_context *ce, + u16 guc_id) +{ + u32 action[] = { + INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET, + guc_id, /* ce->guc_id not stable */ + GUC_CONTEXT_DISABLE + }; + + GEM_BUG_ON(guc_id == GUC_INVALID_LRC_ID); + + intel_context_get(ce); + + intel_guc_send_busy_loop(guc, action, ARRAY_SIZE(action), true); +} + +static u16 prep_context_pending_disable(struct intel_context *ce) +{ + lockdep_assert_held(&ce->guc_state.lock); + + set_context_pending_disable(ce); + clr_context_enabled(ce); + + return ce->guc_id; +} + +static void guc_context_sched_disable(struct intel_context *ce) +{ + struct intel_guc *guc = ce_to_guc(ce); + struct intel_runtime_pm *runtime_pm = &ce->engine->gt->i915->runtime_pm; + unsigned long flags; + u16 guc_id; + intel_wakeref_t wakeref; + + if (context_guc_id_invalid(ce) || + !lrc_desc_registered(guc, ce->guc_id)) { + clr_context_enabled(ce); + goto unpin; + } + + if (!context_enabled(ce)) + goto unpin; + + spin_lock_irqsave(&ce->guc_state.lock, flags); + guc_id = prep_context_pending_disable(ce); + spin_unlock_irqrestore(&ce->guc_state.lock, flags); + + with_intel_runtime_pm(runtime_pm, wakeref) + __guc_context_sched_disable(guc, ce, guc_id); + + return; +unpin: + intel_context_sched_disable_unpin(ce); +} + static inline void guc_lrc_desc_unpin(struct intel_context *ce) { struct intel_engine_cs *engine = ce->engine; @@ -841,6 +941,7 @@ static inline void guc_lrc_desc_unpin(struct intel_context *ce)
GEM_BUG_ON(!lrc_desc_registered(guc, ce->guc_id)); GEM_BUG_ON(ce != __get_context(guc, ce->guc_id)); + GEM_BUG_ON(context_enabled(ce));
spin_lock_irqsave(&ce->guc_state.lock, flags); set_context_destroyed(ce); @@ -922,6 +1023,8 @@ static const struct intel_context_ops guc_context_ops = { .enter = intel_context_enter_engine, .exit = intel_context_exit_engine,
+ .sched_disable = guc_context_sched_disable, + .reset = lrc_reset, .destroy = guc_context_destroy, }; @@ -1354,3 +1457,45 @@ int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
return 0; } + +int intel_guc_sched_done_process_msg(struct intel_guc *guc, + const u32 *msg, + u32 len) +{ + struct intel_context *ce; + unsigned long flags; + u32 desc_idx = msg[0]; + + if (unlikely(len < 2)) { + drm_dbg(&guc_to_gt(guc)->i915->drm, "Invalid length %u", len); + return -EPROTO; + } + + ce = g2h_context_lookup(guc, desc_idx); + if (unlikely(!ce)) + return -EPROTO; + + if (unlikely(context_destroyed(ce) || + (!context_pending_enable(ce) && + !context_pending_disable(ce)))) { + drm_dbg(&guc_to_gt(guc)->i915->drm, + "Bad context sched_state 0x%x, 0x%x, desc_idx %u", + atomic_read(&ce->guc_sched_state_no_lock), + ce->guc_state.sched_state, desc_idx); + return -EPROTO; + } + + if (context_pending_enable(ce)) { + clr_context_pending_enable(ce); + } else if (context_pending_disable(ce)) { + intel_context_sched_disable_unpin(ce); + + spin_lock_irqsave(&ce->guc_state.lock, flags); + clr_context_pending_disable(ce); + spin_unlock_irqrestore(&ce->guc_state.lock, flags); + } + + intel_context_put(ce); + + return 0; +}