Re: [PATCH 24/27] drm/i915/guc: Move fields protected by guc->contexts_lock into sub structure

On 8/18/2021 11:16 PM, Matthew Brost wrote:

To make ownership of locking clear move fields (guc_id, guc_id_ref, guc_id_link) to sub structure guc_id in intel_context.

Signed-off-by: Matthew Brost matthew.brost@intel.com

drivers/gpu/drm/i915/gt/intel_context.c | 4 +- drivers/gpu/drm/i915/gt/intel_context_types.h | 18 +-- drivers/gpu/drm/i915/gt/selftest_hangcheck.c | 6 +- .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 106 +++++++++--------- drivers/gpu/drm/i915/i915_trace.h | 4 +- 5 files changed, 70 insertions(+), 68 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c index 0e48939ec85f..87b84c1d5393 100644 --- a/drivers/gpu/drm/i915/gt/intel_context.c +++ b/drivers/gpu/drm/i915/gt/intel_context.c @@ -398,8 +398,8 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine) spin_lock_init(&ce->guc_active.lock); INIT_LIST_HEAD(&ce->guc_active.requests);

• ce->guc_id = GUC_INVALID_LRC_ID;
• INIT_LIST_HEAD(&ce->guc_id_link);

• ce->guc_id.id = GUC_INVALID_LRC_ID;

• INIT_LIST_HEAD(&ce->guc_id.link);

  /*

  • Initialize fence to be complete as this is expected to be complete

diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h index 9fb0480ccf3b..7a1d1537cf67 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -186,16 +186,18 @@ struct intel_context { u32 prio_count[GUC_CLIENT_PRIORITY_NUM]; } guc_active;

• /* GuC LRC descriptor ID */
• u16 guc_id;

• struct {

• /* GuC LRC descriptor ID */
  

• u16 id;
  
  

• /* GuC LRC descriptor reference count */
• atomic_t guc_id_ref;

• /* GuC LRC descriptor reference count */
  

• atomic_t ref;
  
  

• /*

• * GuC ID link - in list when unpinned but guc_id still valid in GuC
  

• */
  

• struct list_head guc_id_link;

• /*
  

•  * GuC ID link - in list when unpinned but guc_id still valid in GuC
  

•  */
  

• struct list_head link;
  

• } guc_id;

Maybe add a

/* protected via guc->contexts_lock */

somewhere in the struct doc?

Reviewed-by: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com

Daniele

#ifdef CONFIG_DRM_I915_SELFTEST /** diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c index 08f011f893b2..bf43bed905db 100644 --- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c +++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c @@ -789,7 +789,7 @@ static int __igt_reset_engine(struct intel_gt *gt, bool active) if (err) pr_err("[%s] Wait for request %lld:%lld [0x%04X] failed: %d!\n", engine->name, rq->fence.context,

• 			       rq->fence.seqno, rq->context->guc_id, err);
  

• 			       rq->fence.seqno, rq->context->guc_id.id, err);
  }
  
  

  skip:

@@ -1098,7 +1098,7 @@ static int __igt_reset_engines(struct intel_gt *gt, if (err) pr_err("[%s] Wait for request %lld:%lld [0x%04X] failed: %d!\n", engine->name, rq->fence.context,

• 			       rq->fence.seqno, rq->context->guc_id, err);
  

• 			       rq->fence.seqno, rq->context->guc_id.id, err);
  }
  
  count++;
  

@@ -1108,7 +1108,7 @@ static int __igt_reset_engines(struct intel_gt *gt, pr_err("i915_reset_engine(%s:%s): failed to reset request %lld:%lld [0x%04X]\n", engine->name, test_name, rq->fence.context,

• 			       rq->fence.seqno, rq->context->guc_id);
  

• 			       rq->fence.seqno, rq->context->guc_id.id);
  		i915_request_put(rq);
  
  		GEM_TRACE_DUMP();
  

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 bb90bedb1305..c4c018348ac0 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -269,12 +269,12 @@ static inline void decr_context_committed_requests(struct intel_context *ce)

static inline bool context_guc_id_invalid(struct intel_context *ce) {

• return ce->guc_id == GUC_INVALID_LRC_ID;

• return ce->guc_id.id == GUC_INVALID_LRC_ID; }

  static inline void set_context_guc_id_invalid(struct intel_context *ce) {

• ce->guc_id = GUC_INVALID_LRC_ID;

• ce->guc_id.id = GUC_INVALID_LRC_ID; }

  static inline struct intel_guc *ce_to_guc(struct intel_context *ce)

@@ -466,14 +466,14 @@ static int guc_add_request(struct intel_guc *guc, struct i915_request *rq) return 0; }

• GEM_BUG_ON(!atomic_read(&ce->guc_id_ref));

• GEM_BUG_ON(!atomic_read(&ce->guc_id.ref)); GEM_BUG_ON(context_guc_id_invalid(ce));

  /*

  • Corner case where the GuC firmware was blown away and reloaded while
  • this context was pinned.

  */

• if (unlikely(!lrc_desc_registered(guc, ce->guc_id))) {

• if (unlikely(!lrc_desc_registered(guc, ce->guc_id.id))) { err = guc_lrc_desc_pin(ce, false); if (unlikely(err)) return err;

@@ -492,14 +492,14 @@ static int guc_add_request(struct intel_guc *guc, struct i915_request *rq)

if (!enabled) { action[len++] = INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET;

• action[len++] = ce->guc_id;
  

• action[len++] = ce->guc_id.id;
  

  action[len++] = GUC_CONTEXT_ENABLE; set_context_pending_enable(ce); intel_context_get(ce); g2h_len_dw = G2H_LEN_DW_SCHED_CONTEXT_MODE_SET; } else { action[len++] = INTEL_GUC_ACTION_SCHED_CONTEXT;

• action[len++] = ce->guc_id;
  

• action[len++] = ce->guc_id.id;
  

  }

  err = intel_guc_send_nb(guc, action, len, g2h_len_dw);

@@ -1150,12 +1150,12 @@ static int new_guc_id(struct intel_guc *guc) static void __release_guc_id(struct intel_guc *guc, struct intel_context *ce) { if (!context_guc_id_invalid(ce)) {

• ida_simple_remove(&guc->guc_ids, ce->guc_id);
  

• reset_lrc_desc(guc, ce->guc_id);
  

• ida_simple_remove(&guc->guc_ids, ce->guc_id.id);
  

• reset_lrc_desc(guc, ce->guc_id.id);
  

  set_context_guc_id_invalid(ce); }

• if (!list_empty(&ce->guc_id_link))

• list_del_init(&ce->guc_id_link);
  

• if (!list_empty(&ce->guc_id.link))

• list_del_init(&ce->guc_id.link);
  

  }

  static void release_guc_id(struct intel_guc *guc, struct intel_context *ce)

@@ -1177,13 +1177,13 @@ static int steal_guc_id(struct intel_guc *guc) if (!list_empty(&guc->guc_id_list)) { ce = list_first_entry(&guc->guc_id_list, struct intel_context,

• 		      guc_id_link);
  

• 		      guc_id.link);
  
  

• GEM_BUG_ON(atomic_read(&ce->guc_id_ref));
  

• GEM_BUG_ON(atomic_read(&ce->guc_id.ref));
  

  GEM_BUG_ON(context_guc_id_invalid(ce));

• list_del_init(&ce->guc_id_link);
  

• guc_id = ce->guc_id;
  

• list_del_init(&ce->guc_id.link);
  

• guc_id = ce->guc_id.id;
  
  

  spin_lock(&ce->guc_state.lock); clr_context_registered(ce);

@@ -1219,7 +1219,7 @@ static int pin_guc_id(struct intel_guc *guc, struct intel_context *ce) int ret = 0; unsigned long flags, tries = PIN_GUC_ID_TRIES;

• GEM_BUG_ON(atomic_read(&ce->guc_id_ref));

• GEM_BUG_ON(atomic_read(&ce->guc_id.ref));

  try_again: spin_lock_irqsave(&guc->contexts_lock, flags);

@@ -1227,20 +1227,20 @@ static int pin_guc_id(struct intel_guc *guc, struct intel_context *ce) might_lock(&ce->guc_state.lock);

if (context_guc_id_invalid(ce)) {

• ret = assign_guc_id(guc, &ce->guc_id);
  

• ret = assign_guc_id(guc, &ce->guc_id.id);
  

  if (ret) goto out_unlock; ret = 1; /* Indidcates newly assigned guc_id */ }

• if (!list_empty(&ce->guc_id_link))

• list_del_init(&ce->guc_id_link);
  

• atomic_inc(&ce->guc_id_ref);

• if (!list_empty(&ce->guc_id.link))

• list_del_init(&ce->guc_id.link);
  

• atomic_inc(&ce->guc_id.ref);

  out_unlock: spin_unlock_irqrestore(&guc->contexts_lock, flags);

  /*

• * -EAGAIN indicates no guc_ids are available, let's retire any
  

• * -EAGAIN indicates no guc_id are available, let's retire any
  

  • outstanding requests to see if that frees up a guc_id. If the first
  • retire didn't help, insert a sleep with the timeslice duration before
  • attempting to retire more requests. Double the sleep period each

@@ -1268,15 +1268,15 @@ static void unpin_guc_id(struct intel_guc *guc, struct intel_context *ce) { unsigned long flags;

• GEM_BUG_ON(atomic_read(&ce->guc_id_ref) < 0);

• GEM_BUG_ON(atomic_read(&ce->guc_id.ref) < 0);

  if (unlikely(context_guc_id_invalid(ce))) return;

  spin_lock_irqsave(&guc->contexts_lock, flags);

• if (!context_guc_id_invalid(ce) && list_empty(&ce->guc_id_link) &&

•    !atomic_read(&ce->guc_id_ref))
  

• list_add_tail(&ce->guc_id_link, &guc->guc_id_list);
  

• if (!context_guc_id_invalid(ce) && list_empty(&ce->guc_id.link) &&

•    !atomic_read(&ce->guc_id.ref))
  

• list_add_tail(&ce->guc_id.link, &guc->guc_id_list);
  

  spin_unlock_irqrestore(&guc->contexts_lock, flags); }

@@ -1299,12 +1299,12 @@ static int register_context(struct intel_context *ce, bool loop) { struct intel_guc *guc = ce_to_guc(ce); u32 offset = intel_guc_ggtt_offset(guc, guc->lrc_desc_pool) +

• ce->guc_id * sizeof(struct guc_lrc_desc);
  

• ce->guc_id.id * sizeof(struct guc_lrc_desc);
  

  int ret;

  trace_intel_context_register(ce);

• ret = __guc_action_register_context(guc, ce->guc_id, offset, loop);

• ret = __guc_action_register_context(guc, ce->guc_id.id, offset, loop); if (likely(!ret)) { unsigned long flags;

@@ -1374,7 +1374,7 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop) struct intel_engine_cs *engine = ce->engine; struct intel_runtime_pm *runtime_pm = engine->uncore->rpm; struct intel_guc *guc = &engine->gt->uc.guc;

• u32 desc_idx = ce->guc_id;

• u32 desc_idx = ce->guc_id.id; struct guc_lrc_desc *desc; bool context_registered; intel_wakeref_t wakeref;

@@ -1437,7 +1437,7 @@ static int guc_lrc_desc_pin(struct intel_context *ce, bool loop) * context whose guc_id was stolen. */ with_intel_runtime_pm(runtime_pm, wakeref)

• 	ret = deregister_context(ce, ce->guc_id, loop);
  

• 	ret = deregister_context(ce, ce->guc_id.id, loop);
  

  if (unlikely(ret == -ENODEV)) { ret = 0; /* Will get registered later */ }

@@ -1509,7 +1509,7 @@ static void __guc_context_sched_enable(struct intel_guc *guc, { u32 action[] = { INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET,

• ce->guc_id,
  

• ce->guc_id.id,
  

  GUC_CONTEXT_ENABLE };

@@ -1525,7 +1525,7 @@ static void __guc_context_sched_disable(struct intel_guc *guc, { u32 action[] = { INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET,

• guc_id,	/* ce->guc_id not stable */
  

• guc_id,	/* ce->guc_id.id not stable */
  

  GUC_CONTEXT_DISABLE };

@@ -1570,7 +1570,7 @@ static u16 prep_context_pending_disable(struct intel_context *ce) guc_blocked_fence_reinit(ce); intel_context_get(ce);

• return ce->guc_id;

• return ce->guc_id.id; }

  static struct i915_sw_fence *guc_context_block(struct intel_context *ce)

@@ -1625,7 +1625,7 @@ static void guc_context_unblock(struct intel_context *ce) if (unlikely(submission_disabled(guc) || intel_context_is_banned(ce) || context_guc_id_invalid(ce) ||

•      !lrc_desc_registered(guc, ce->guc_id) ||
  

•      !lrc_desc_registered(guc, ce->guc_id.id) ||
  !intel_context_is_pinned(ce) ||
  context_pending_disable(ce) ||
  context_blocked(ce) > 1)) {
  

@@ -1730,7 +1730,7 @@ static void guc_context_ban(struct intel_context *ce, struct i915_request *rq) if (!context_guc_id_invalid(ce)) with_intel_runtime_pm(runtime_pm, wakeref) __guc_context_set_preemption_timeout(guc,

• 						     ce->guc_id,
  

• 						     ce->guc_id.id,
  					     1);
  

  spin_unlock_irqrestore(&ce->guc_state.lock, flags); }

@@ -1746,7 +1746,7 @@ static void guc_context_sched_disable(struct intel_context *ce) bool enabled;

if (submission_disabled(guc) || context_guc_id_invalid(ce) ||

•    !lrc_desc_registered(guc, ce->guc_id)) {
  

•    !lrc_desc_registered(guc, ce->guc_id.id)) {
  

  spin_lock_irqsave(&ce->guc_state.lock, flags); clr_context_enabled(ce); spin_unlock_irqrestore(&ce->guc_state.lock, flags);

@@ -1793,11 +1793,11 @@ static inline void guc_lrc_desc_unpin(struct intel_context *ce) { struct intel_guc *guc = ce_to_guc(ce);

• GEM_BUG_ON(!lrc_desc_registered(guc, ce->guc_id));
• GEM_BUG_ON(ce != __get_context(guc, ce->guc_id));

• GEM_BUG_ON(!lrc_desc_registered(guc, ce->guc_id.id));
• GEM_BUG_ON(ce != __get_context(guc, ce->guc_id.id)); GEM_BUG_ON(context_enabled(ce));

• deregister_context(ce, ce->guc_id, true);

• deregister_context(ce, ce->guc_id.id, true); }

  static void __guc_context_destroy(struct intel_context *ce)

@@ -1842,7 +1842,7 @@ static void guc_context_destroy(struct kref *kref) __guc_context_destroy(ce); return; } else if (submission_disabled(guc) ||

•    !lrc_desc_registered(guc, ce->guc_id)) {
  

•    !lrc_desc_registered(guc, ce->guc_id.id)) {
  

  release_guc_id(guc, ce); __guc_context_destroy(ce); return;

@@ -1851,10 +1851,10 @@ static void guc_context_destroy(struct kref *kref) /* * We have to acquire the context spinlock and check guc_id again, if it * is valid it hasn't been stolen and needs to be deregistered. We

• * delete this context from the list of unpinned guc_ids available to
  

• * delete this context from the list of unpinned guc_id available to
  

  • steal to seal a race with guc_lrc_desc_pin(). When the G2H CTB
  • returns indicating this context has been deregistered the guc_id is

• * returned to the pool of available guc_ids.
  

• * returned to the pool of available guc_id.
  

  */ spin_lock_irqsave(&guc->contexts_lock, flags); if (context_guc_id_invalid(ce)) {

@@ -1863,8 +1863,8 @@ static void guc_context_destroy(struct kref *kref) return; }

• if (!list_empty(&ce->guc_id_link))

• list_del_init(&ce->guc_id_link);
  

• if (!list_empty(&ce->guc_id.link))

• list_del_init(&ce->guc_id.link);
  

  spin_unlock_irqrestore(&guc->contexts_lock, flags);

  /* Seal race with Reset */

@@ -1909,7 +1909,7 @@ static void guc_context_set_prio(struct intel_guc *guc, { u32 action[] = { INTEL_GUC_ACTION_SET_CONTEXT_PRIORITY,

• ce->guc_id,
  

• ce->guc_id.id,
  

  prio, };

@@ -2044,7 +2044,7 @@ static void remove_from_context(struct i915_request *rq) decr_context_committed_requests(ce); spin_unlock_irq(&ce->guc_state.lock);

• atomic_dec(&ce->guc_id_ref);

• atomic_dec(&ce->guc_id.ref); i915_request_notify_execute_cb_imm(rq); }

@@ -2111,7 +2111,7 @@ static void guc_signal_context_fence(struct intel_context *ce) static bool context_needs_register(struct intel_context *ce, bool new_guc_id) { return (new_guc_id || test_bit(CONTEXT_LRCA_DIRTY, &ce->flags) ||

• !lrc_desc_registered(ce_to_guc(ce), ce->guc_id)) &&
  

• !lrc_desc_registered(ce_to_guc(ce), ce->guc_id.id)) &&
  

  !submission_disabled(ce_to_guc(ce)); }

@@ -2166,11 +2166,11 @@ static int guc_request_alloc(struct i915_request *rq) /* * Call pin_guc_id here rather than in the pinning step as with * dma_resv, contexts can be repeatedly pinned / unpinned trashing the

• * guc_ids and creating horrible race conditions. This is especially bad
  

• * when guc_ids are being stolen due to over subscription. By the time
  

• * guc_id and creating horrible race conditions. This is especially bad
  

• * when guc_id are being stolen due to over subscription. By the time
  

  • this function is reached, it is guaranteed that the guc_id will be
  • persistent until the generated request is retired. Thus, sealing these

• * race conditions. It is still safe to fail here if guc_ids are
  

• * race conditions. It is still safe to fail here if guc_id are
  

  • exhausted and return -EAGAIN to the user indicating that they can try
  • again in the future.

@@ -2180,7 +2180,7 @@ static int guc_request_alloc(struct i915_request *rq) * decremented on each retire. When it is zero, a lock around the * increment (in pin_guc_id) is needed to seal a race with unpin_guc_id. */

• if (atomic_add_unless(&ce->guc_id_ref, 1, 0))

• if (atomic_add_unless(&ce->guc_id.ref, 1, 0)) goto out;

  ret = pin_guc_id(guc, ce); /* returns 1 if new guc_id assigned */

@@ -2193,7 +2193,7 @@ static int guc_request_alloc(struct i915_request *rq) disable_submission(guc); goto out; /* GPU will be reset */ }

• 	atomic_dec(&ce->guc_id_ref);
  

• 	atomic_dec(&ce->guc_id.ref);
  unpin_guc_id(guc, ce);
  return ret;
  

  }

@@ -3028,7 +3028,7 @@ void intel_guc_submission_print_info(struct intel_guc *guc,

priolist_for_each_request(rq, pl)
	drm_printf(p, "guc_id=%u, seqno=%llu\n",

• 		   rq->context->guc_id,
  

• 		   rq->context->guc_id.id,
  	   rq->fence.seqno);
  

  } spin_unlock_irqrestore(&sched_engine->lock, flags);

@@ -3059,7 +3059,7 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc,

xa_lock_irqsave(&guc->context_lookup, flags); xa_for_each(&guc->context_lookup, index, ce) {

• drm_printf(p, "GuC lrc descriptor %u:\n", ce->guc_id);
  

• drm_printf(p, "GuC lrc descriptor %u:\n", ce->guc_id.id);
  

  drm_printf(p, "\tHW Context Desc: 0x%08x\n", ce->lrc.lrca); drm_printf(p, "\t\tLRC Head: Internal %u, Memory %u\n", ce->ring->head,

@@ -3070,7 +3070,7 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc, drm_printf(p, "\t\tContext Pin Count: %u\n", atomic_read(&ce->pin_count)); drm_printf(p, "\t\tGuC ID Ref Count: %u\n",

• 	   atomic_read(&ce->guc_id_ref));
  

• 	   atomic_read(&ce->guc_id.ref));
  

  drm_printf(p, "\t\tSchedule State: 0x%x\n\n", ce->guc_state.sched_state);

diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h index 6f882e72ed11..0574f5c7a985 100644 --- a/drivers/gpu/drm/i915/i915_trace.h +++ b/drivers/gpu/drm/i915/i915_trace.h @@ -805,7 +805,7 @@ DECLARE_EVENT_CLASS(i915_request, __entry->dev = rq->engine->i915->drm.primary->index; __entry->class = rq->engine->uabi_class; __entry->instance = rq->engine->uabi_instance;

• 	   __entry->guc_id = rq->context->guc_id;
  

• 	   __entry->guc_id = rq->context->guc_id.id;
     __entry->ctx = rq->fence.context;
     __entry->seqno = rq->fence.seqno;
     __entry->tail = rq->tail;
  

@@ -907,7 +907,7 @@ DECLARE_EVENT_CLASS(intel_context, ),

    TP_fast_assign(

• 	   __entry->guc_id = ce->guc_id;
  

• 	   __entry->guc_id = ce->guc_id.id;
     __entry->pin_count = atomic_read(&ce->pin_count);
     __entry->sched_state = ce->guc_state.sched_state;
     __entry->guc_prio = ce->guc_active.prio;