On Mon, Jul 26, 2021 at 10:49:37AM -0700, Daniele Ceraolo Spurio wrote: > > > On 7/22/2021 4:54 PM, Matthew Brost wrote: > > This adds GuC backend support for i915_request_cancel(), which in turn > > makes CONFIG_DRM_I915_REQUEST_TIMEOUT work. > > > > This implemenation makes use of fence while there is likely simplier > > options. A fence was choosen because of another feature coming soon > > which requires a user to block on a context until scheduling is > > disabled. In that case we return the fence to the user and the user can > > wait on that fence. > > > > v2: > > (Daniele) > > - A comment about locking the blocked incr / decr > > - A comments about the use of the fence > > - Update commit message explaining why fence > > - Delete redundant check blocked count in unblock function > > - Ring buffer implementation > > - Comment about blocked in submission path > > - Shorter rpm path > > > > Signed-off-by: Matthew Brost <matthew.br...@intel.com> > > Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com> > > --- > > drivers/gpu/drm/i915/gt/intel_context.c | 13 ++ > > drivers/gpu/drm/i915/gt/intel_context.h | 7 + > > drivers/gpu/drm/i915/gt/intel_context_types.h | 7 + > > .../drm/i915/gt/intel_execlists_submission.c | 18 ++ > > .../gpu/drm/i915/gt/intel_ring_submission.c | 16 ++ > > .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 175 ++++++++++++++++++ > > drivers/gpu/drm/i915/i915_request.c | 14 +- > > 7 files changed, 237 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/intel_context.c > > b/drivers/gpu/drm/i915/gt/intel_context.c > > index 237b70e98744..477c42d7d693 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_context.c > > +++ b/drivers/gpu/drm/i915/gt/intel_context.c > > @@ -366,6 +366,12 @@ static int __intel_context_active(struct i915_active > > *active) > > return 0; > > } > > +static int sw_fence_dummy_notify(struct i915_sw_fence *sf, > > + enum i915_sw_fence_notify state) > > +{ > > + return NOTIFY_DONE; > > +} > > + > > void > > intel_context_init(struct intel_context *ce, struct intel_engine_cs > > *engine) > > { > > @@ -399,6 +405,13 @@ intel_context_init(struct intel_context *ce, struct > > intel_engine_cs *engine) > > ce->guc_id = GUC_INVALID_LRC_ID; > > INIT_LIST_HEAD(&ce->guc_id_link); > > + /* > > + * Initialize fence to be complete as this is expected to be complete > > + * unless there is a pending schedule disable outstanding. > > + */ > > + i915_sw_fence_init(&ce->guc_blocked, sw_fence_dummy_notify); > > + i915_sw_fence_commit(&ce->guc_blocked); > > + > > i915_active_init(&ce->active, > > __intel_context_active, __intel_context_retire, 0); > > } > > diff --git a/drivers/gpu/drm/i915/gt/intel_context.h > > b/drivers/gpu/drm/i915/gt/intel_context.h > > index 814d9277096a..876bdb08303c 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_context.h > > +++ b/drivers/gpu/drm/i915/gt/intel_context.h > > @@ -70,6 +70,13 @@ intel_context_is_pinned(struct intel_context *ce) > > return atomic_read(&ce->pin_count); > > } > > +static inline void intel_context_cancel_request(struct intel_context *ce, > > + struct i915_request *rq) > > +{ > > + GEM_BUG_ON(!ce->ops->cancel_request); > > + return ce->ops->cancel_request(ce, rq); > > +} > > + > > /** > > * intel_context_unlock_pinned - Releases the earlier locking of 'pinned' > > status > > * @ce - the context > > diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h > > b/drivers/gpu/drm/i915/gt/intel_context_types.h > > index 57c19ee3e313..005a64f2afa7 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_context_types.h > > +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h > > @@ -13,6 +13,7 @@ > > #include <linux/types.h> > > #include "i915_active_types.h" > > +#include "i915_sw_fence.h" > > #include "i915_utils.h" > > #include "intel_engine_types.h" > > #include "intel_sseu.h" > > @@ -42,6 +43,9 @@ struct intel_context_ops { > > void (*unpin)(struct intel_context *ce); > > void (*post_unpin)(struct intel_context *ce); > > + void (*cancel_request)(struct intel_context *ce, > > + struct i915_request *rq); > > + > > void (*enter)(struct intel_context *ce); > > void (*exit)(struct intel_context *ce); > > @@ -184,6 +188,9 @@ struct intel_context { > > * GuC ID link - in list when unpinned but guc_id still valid in GuC > > */ > > struct list_head guc_id_link; > > + > > + /* GuC context blocked fence */ > > + struct i915_sw_fence guc_blocked; > > }; > > #endif /* __INTEL_CONTEXT_TYPES__ */ > > diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > index 60427b106bad..e7b42222b71d 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c > > @@ -114,6 +114,7 @@ > > #include "gen8_engine_cs.h" > > #include "intel_breadcrumbs.h" > > #include "intel_context.h" > > +#include "intel_engine_heartbeat.h" > > #include "intel_engine_pm.h" > > #include "intel_engine_stats.h" > > #include "intel_execlists_submission.h" > > @@ -2587,11 +2588,26 @@ static int execlists_context_alloc(struct > > intel_context *ce) > > return lrc_alloc(ce, ce->engine); > > } > > +static void execlists_context_cancel_request(struct intel_context *ce, > > + struct i915_request *rq) > > +{ > > + struct intel_engine_cs *engine = NULL; > > + > > + i915_request_active_engine(rq, &engine); > > + > > + if (engine && intel_engine_pulse(engine)) > > + intel_gt_handle_error(engine->gt, engine->mask, 0, > > + "request cancellation by %s", > > + current->comm); > > +} > > + > > static const struct intel_context_ops execlists_context_ops = { > > .flags = COPS_HAS_INFLIGHT, > > .alloc = execlists_context_alloc, > > + .cancel_request = execlists_context_cancel_request, > > + > > .pre_pin = execlists_context_pre_pin, > > .pin = execlists_context_pin, > > .unpin = lrc_unpin, > > @@ -3604,6 +3620,8 @@ static const struct intel_context_ops > > virtual_context_ops = { > > .alloc = virtual_context_alloc, > > + .cancel_request = execlists_context_cancel_request, > > + > > .pre_pin = virtual_context_pre_pin, > > .pin = virtual_context_pin, > > .unpin = lrc_unpin, > > diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c > > b/drivers/gpu/drm/i915/gt/intel_ring_submission.c > > index 05bb9f449df1..2958e2fae380 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c > > +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c > > @@ -16,6 +16,7 @@ > > #include "intel_reset.h" > > #include "intel_ring.h" > > #include "shmem_utils.h" > > +#include "intel_engine_heartbeat.h" > > /* Rough estimate of the typical request size, performing a flush, > > * set-context and then emitting the batch. > > @@ -604,9 +605,24 @@ static void ring_context_ban(struct intel_context *ce, > > } > > } > > +static void ring_context_cancel_request(struct intel_context *ce, > > + struct i915_request *rq) > > +{ > > + struct intel_engine_cs *engine = NULL; > > + > > + i915_request_active_engine(rq, &engine); > > + > > + if (engine && intel_engine_pulse(engine)) > > + intel_gt_handle_error(engine->gt, engine->mask, 0, > > + "request cancellation by %s", > > + current->comm); > > +} > > + > > static const struct intel_context_ops ring_context_ops = { > > .alloc = ring_context_alloc, > > + .cancel_request = ring_context_cancel_request, > > + > > .ban = ring_context_ban, > > .pre_pin = ring_context_pre_pin, > > 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 3b9ba3bdd425..a26754b9b940 100644 > > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > > @@ -81,6 +81,11 @@ guc_create_virtual(struct intel_engine_cs **siblings, > > unsigned int count); > > */ > > #define SCHED_STATE_NO_LOCK_ENABLED BIT(0) > > #define SCHED_STATE_NO_LOCK_PENDING_ENABLE BIT(1) > > +#define SCHED_STATE_NO_LOCK_BLOCKED_SHIFT 2 > > +#define SCHED_STATE_NO_LOCK_BLOCKED \ > > + BIT(SCHED_STATE_NO_LOCK_BLOCKED_SHIFT) > > +#define SCHED_STATE_NO_LOCK_BLOCKED_MASK \ > > + (0xffff << SCHED_STATE_NO_LOCK_BLOCKED_SHIFT) > > static inline bool context_enabled(struct intel_context *ce) > > { > > return (atomic_read(&ce->guc_sched_state_no_lock) & > > @@ -116,6 +121,30 @@ static inline void clr_context_pending_enable(struct > > intel_context *ce) > > &ce->guc_sched_state_no_lock); > > } > > +static inline u32 context_blocked(struct intel_context *ce) > > +{ > > + return (atomic_read(&ce->guc_sched_state_no_lock) & > > + SCHED_STATE_NO_LOCK_BLOCKED_MASK) >> > > + SCHED_STATE_NO_LOCK_BLOCKED_SHIFT; > > +} > > + > > +static inline void incr_context_blocked(struct intel_context *ce) > > +{ > > + lockdep_assert_held(&ce->engine->sched_engine->lock); > > + atomic_add(SCHED_STATE_NO_LOCK_BLOCKED, > > + &ce->guc_sched_state_no_lock); > > + GEM_BUG_ON(!context_blocked(ce)); /* Overflow check */ > > +} > > + > > +static inline void decr_context_blocked(struct intel_context *ce) > > +{ > > + lockdep_assert_held(&ce->engine->sched_engine->lock); > > + GEM_BUG_ON(!context_blocked(ce)); > > + > > + atomic_sub(SCHED_STATE_NO_LOCK_BLOCKED, > > + &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 > > @@ -404,6 +433,14 @@ static int guc_add_request(struct intel_guc *guc, > > struct i915_request *rq) > > if (unlikely(err)) > > goto out; > > } > > + > > + /* > > + * The request / context will be run on the hardware when scheduling > > + * gets enabled in the unblock. > > + */ > > + if (unlikely(context_blocked(ce))) > > + goto out; > > + > > enabled = context_enabled(ce); > > if (!enabled) { > > @@ -532,6 +569,7 @@ static void __guc_context_destroy(struct intel_context > > *ce); > > static void release_guc_id(struct intel_guc *guc, struct intel_context > > *ce); > > static void guc_signal_context_fence(struct intel_context *ce); > > static void guc_cancel_context_requests(struct intel_context *ce); > > +static void guc_blocked_fence_complete(struct intel_context *ce); > > static void scrub_guc_desc_for_outstanding_g2h(struct intel_guc *guc) > > { > > @@ -579,6 +617,10 @@ static void scrub_guc_desc_for_outstanding_g2h(struct > > intel_guc *guc) > > } > > intel_context_sched_disable_unpin(ce); > > atomic_dec(&guc->outstanding_submission_g2h); > > + spin_lock_irqsave(&ce->guc_state.lock, flags); > > + guc_blocked_fence_complete(ce); > > + spin_unlock_irqrestore(&ce->guc_state.lock, flags); > > + > > intel_context_put(ce); > > } > > } > > @@ -1353,6 +1395,21 @@ static void guc_context_post_unpin(struct > > intel_context *ce) > > lrc_post_unpin(ce); > > } > > +static void __guc_context_sched_enable(struct intel_guc *guc, > > + struct intel_context *ce) > > +{ > > + u32 action[] = { > > + INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET, > > + ce->guc_id, > > + GUC_CONTEXT_ENABLE > > + }; > > + > > + trace_intel_context_sched_enable(ce); > > + > > + guc_submission_send_busy_loop(guc, action, ARRAY_SIZE(action), > > + G2H_LEN_DW_SCHED_CONTEXT_MODE_SET, true); > > +} > > + > > static void __guc_context_sched_disable(struct intel_guc *guc, > > struct intel_context *ce, > > u16 guc_id) > > @@ -1371,17 +1428,130 @@ static void __guc_context_sched_disable(struct > > intel_guc *guc, > > G2H_LEN_DW_SCHED_CONTEXT_MODE_SET, true); > > } > > +static void guc_blocked_fence_complete(struct intel_context *ce) > > +{ > > + lockdep_assert_held(&ce->guc_state.lock); > > + > > + if (!i915_sw_fence_done(&ce->guc_blocked)) > > + i915_sw_fence_complete(&ce->guc_blocked); > > +} > > + > > +static void guc_blocked_fence_reinit(struct intel_context *ce) > > +{ > > + lockdep_assert_held(&ce->guc_state.lock); > > + GEM_BUG_ON(!i915_sw_fence_done(&ce->guc_blocked)); > > + > > + /* > > + * This fence is always complete unless a pending schedule disable is > > + * outstanding. We arm the fence here and complete it when we receive > > + * the pending schedule disable complete message. > > + */ > > + i915_sw_fence_fini(&ce->guc_blocked); > > + i915_sw_fence_reinit(&ce->guc_blocked); > > + i915_sw_fence_await(&ce->guc_blocked); > > + i915_sw_fence_commit(&ce->guc_blocked); > > +} > > + > > 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); > > + guc_blocked_fence_reinit(ce); > > intel_context_get(ce); > > return ce->guc_id; > > } > > +static struct i915_sw_fence *guc_context_block(struct intel_context *ce) > > +{ > > + struct intel_guc *guc = ce_to_guc(ce); > > + struct i915_sched_engine *sched_engine = ce->engine->sched_engine; > > + unsigned long flags; > > + struct intel_runtime_pm *runtime_pm = ce->engine->uncore->rpm; > > + intel_wakeref_t wakeref; > > + u16 guc_id; > > + bool enabled; > > + > > + /* Sync with submission path and unblock */ > > + spin_lock_irqsave(&sched_engine->lock, flags); > > + incr_context_blocked(ce); > > + spin_unlock_irqrestore(&sched_engine->lock, flags); > > + > > + spin_lock_irqsave(&ce->guc_state.lock, flags); > > + enabled = context_enabled(ce); > > + if (unlikely(!enabled || submission_disabled(guc))) { > > + if (enabled) > > + clr_context_enabled(ce); > > + spin_unlock_irqrestore(&ce->guc_state.lock, flags); > > + return &ce->guc_blocked; > > + } > > + > > + /* > > + * We add +2 here as the schedule disable complete CTB handler calls > > + * intel_context_sched_disable_unpin (-2 to pin_count). > > + */ > > + atomic_add(2, &ce->pin_count); > > + > > + 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 &ce->guc_blocked; > > +} > > + > > +static void guc_context_unblock(struct intel_context *ce) > > +{ > > + struct intel_guc *guc = ce_to_guc(ce); > > + struct i915_sched_engine *sched_engine = ce->engine->sched_engine; > > + unsigned long flags; > > + struct intel_runtime_pm *runtime_pm = ce->engine->uncore->rpm; > > + intel_wakeref_t wakeref; > > + > > + GEM_BUG_ON(context_enabled(ce)); > > + > > + spin_lock_irqsave(&ce->guc_state.lock, flags); > > + if (unlikely(submission_disabled(guc) || > > + !intel_context_is_pinned(ce) || > > + context_pending_disable(ce) || > > + context_blocked(ce) > 1)) { > > + spin_unlock_irqrestore(&ce->guc_state.lock, flags); > > + goto out; > > + } > > + > > + set_context_pending_enable(ce); > > + set_context_enabled(ce); > > + intel_context_get(ce); > > + spin_unlock_irqrestore(&ce->guc_state.lock, flags); > > + > > + with_intel_runtime_pm(runtime_pm, wakeref) > > + __guc_context_sched_enable(guc, ce); > > + > > +out: > > + spin_lock_irqsave(&sched_engine->lock, flags); > > + decr_context_blocked(ce); > > + spin_unlock_irqrestore(&sched_engine->lock, flags);. > > As we discussed offline, it might be better to cover the whole block/unblock > logic with ce->guc_state.lock. That way we can make sure we're not racing > the incr/decr calls with the swapping locks. > Apart from this, the patch LGTM. >
Yep, agree. The fact I had to look at this code for about 10 minutes to convince myself it was safe isn't good. Much better to have it covered by ce->guc_state.lock. Will fix. Matt > Daniele > > > +} > > + > > +static void guc_context_cancel_request(struct intel_context *ce, > > + struct i915_request *rq) > > +{ > > + if (i915_sw_fence_signaled(&rq->submit)) { > > + struct i915_sw_fence *fence = guc_context_block(ce); > > + > > + i915_sw_fence_wait(fence); > > + if (!i915_request_completed(rq)) { > > + __i915_request_skip(rq); > > + guc_reset_state(ce, intel_ring_wrap(ce->ring, rq->head), > > + true); > > + } > > + guc_context_unblock(ce); > > + } > > +} > > + > > static void __guc_context_set_preemption_timeout(struct intel_guc *guc, > > u16 guc_id, > > u32 preemption_timeout) > > @@ -1641,6 +1811,8 @@ static const struct intel_context_ops guc_context_ops > > = { > > .ban = guc_context_ban, > > + .cancel_request = guc_context_cancel_request, > > + > > .enter = intel_context_enter_engine, > > .exit = intel_context_exit_engine, > > @@ -1836,6 +2008,8 @@ static const struct intel_context_ops > > virtual_guc_context_ops = { > > .ban = guc_context_ban, > > + .cancel_request = guc_context_cancel_request, > > + > > .enter = guc_virtual_context_enter, > > .exit = guc_virtual_context_exit, > > @@ -2294,6 +2468,7 @@ int intel_guc_sched_done_process_msg(struct intel_guc > > *guc, > > clr_context_banned(ce); > > clr_context_pending_disable(ce); > > __guc_signal_context_fence(ce); > > + guc_blocked_fence_complete(ce); > > spin_unlock_irqrestore(&ce->guc_state.lock, flags); > > if (banned) { > > diff --git a/drivers/gpu/drm/i915/i915_request.c > > b/drivers/gpu/drm/i915/i915_request.c > > index 28f38b02a5d2..541a20371502 100644 > > --- a/drivers/gpu/drm/i915/i915_request.c > > +++ b/drivers/gpu/drm/i915/i915_request.c > > @@ -710,18 +710,6 @@ void i915_request_unsubmit(struct i915_request > > *request) > > spin_unlock_irqrestore(&engine->sched_engine->lock, flags); > > } > > -static void __cancel_request(struct i915_request *rq) > > -{ > > - struct intel_engine_cs *engine = NULL; > > - > > - i915_request_active_engine(rq, &engine); > > - > > - if (engine && intel_engine_pulse(engine)) > > - intel_gt_handle_error(engine->gt, engine->mask, 0, > > - "request cancellation by %s", > > - current->comm); > > -} > > - > > void i915_request_cancel(struct i915_request *rq, int error) > > { > > if (!i915_request_set_error_once(rq, error)) > > @@ -729,7 +717,7 @@ void i915_request_cancel(struct i915_request *rq, int > > error) > > set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags); > > - __cancel_request(rq); > > + intel_context_cancel_request(rq->context, rq); > > } > > static int __i915_sw_fence_call >