drm/i915/guc: Direct all breadcrumbs for a class to single breadcrumbs

With GuC virtual engines the physical engine which a request executes
and completes on isn't known to the i915. Therefore we can't attach a
request to a physical engines breadcrumbs. To work around this we create
a single breadcrumbs per engine class when using GuC submission and
direct all physical engine interrupts to this breadcrumbs.

v2:
 (John H)
  - Rework header file structure so intel_engine_mask_t can be in
    intel_engine_types.h

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
CC: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-6-matthew.brost@intel.com

diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
index 38cc427..2007dc6 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
@@ -15,28 +15,14 @@
 #include "intel_gt_pm.h"
 #include "intel_gt_requests.h"
 
-static bool irq_enable(struct intel_engine_cs *engine)
+static bool irq_enable(struct intel_breadcrumbs *b)
 {
-       if (!engine->irq_enable)
-               return false;
-
-       /* Caller disables interrupts */
-       spin_lock(&engine->gt->irq_lock);
-       engine->irq_enable(engine);
-       spin_unlock(&engine->gt->irq_lock);
-
-       return true;
+       return intel_engine_irq_enable(b->irq_engine);
 }
 
-static void irq_disable(struct intel_engine_cs *engine)
+static void irq_disable(struct intel_breadcrumbs *b)
 {
-       if (!engine->irq_disable)
-               return;
-
-       /* Caller disables interrupts */
-       spin_lock(&engine->gt->irq_lock);
-       engine->irq_disable(engine);
-       spin_unlock(&engine->gt->irq_lock);
+       intel_engine_irq_disable(b->irq_engine);
 }
 
 static void __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
@@ -57,7 +43,7 @@ static void __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
        WRITE_ONCE(b->irq_armed, true);
 
        /* Requests may have completed before we could enable the interrupt. */
-       if (!b->irq_enabled++ && irq_enable(b->irq_engine))
+       if (!b->irq_enabled++ && b->irq_enable(b))
                irq_work_queue(&b->irq_work);
 }
 
@@ -76,7 +62,7 @@ static void __intel_breadcrumbs_disarm_irq(struct intel_breadcrumbs *b)
 {
        GEM_BUG_ON(!b->irq_enabled);
        if (!--b->irq_enabled)
-               irq_disable(b->irq_engine);
+               b->irq_disable(b);
 
        WRITE_ONCE(b->irq_armed, false);
        intel_gt_pm_put_async(b->irq_engine->gt);
@@ -281,7 +267,7 @@ intel_breadcrumbs_create(struct intel_engine_cs *irq_engine)
        if (!b)
                return NULL;
 
-       b->irq_engine = irq_engine;
+       kref_init(&b->ref);
 
        spin_lock_init(&b->signalers_lock);
        INIT_LIST_HEAD(&b->signalers);
@@ -290,6 +276,10 @@ intel_breadcrumbs_create(struct intel_engine_cs *irq_engine)
        spin_lock_init(&b->irq_lock);
        init_irq_work(&b->irq_work, signal_irq_work);
 
+       b->irq_engine = irq_engine;
+       b->irq_enable = irq_enable;
+       b->irq_disable = irq_disable;
+
        return b;
 }
 
@@ -303,9 +293,9 @@ void intel_breadcrumbs_reset(struct intel_breadcrumbs *b)
        spin_lock_irqsave(&b->irq_lock, flags);
 
        if (b->irq_enabled)
-               irq_enable(b->irq_engine);
+               b->irq_enable(b);
        else
-               irq_disable(b->irq_engine);
+               b->irq_disable(b);
 
        spin_unlock_irqrestore(&b->irq_lock, flags);
 }
@@ -325,11 +315,14 @@ void __intel_breadcrumbs_park(struct intel_breadcrumbs *b)
        }
 }
 
-void intel_breadcrumbs_free(struct intel_breadcrumbs *b)
+void intel_breadcrumbs_free(struct kref *kref)
 {
+       struct intel_breadcrumbs *b = container_of(kref, typeof(*b), ref);
+
        irq_work_sync(&b->irq_work);
        GEM_BUG_ON(!list_empty(&b->signalers));
        GEM_BUG_ON(b->irq_armed);
+
        kfree(b);
 }
 

diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h
index 3ce5ce2..be0d4f3 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h
@@ -9,7 +9,7 @@
 #include <linux/atomic.h>
 #include <linux/irq_work.h>
 
-#include "intel_engine_types.h"
+#include "intel_breadcrumbs_types.h"
 
 struct drm_printer;
 struct i915_request;
@@ -17,7 +17,7 @@ struct intel_breadcrumbs;
 
 struct intel_breadcrumbs *
 intel_breadcrumbs_create(struct intel_engine_cs *irq_engine);
-void intel_breadcrumbs_free(struct intel_breadcrumbs *b);
+void intel_breadcrumbs_free(struct kref *kref);
 
 void intel_breadcrumbs_reset(struct intel_breadcrumbs *b);
 void __intel_breadcrumbs_park(struct intel_breadcrumbs *b);
@@ -48,4 +48,16 @@ void i915_request_cancel_breadcrumb(struct i915_request *request);
 void intel_context_remove_breadcrumbs(struct intel_context *ce,
                                      struct intel_breadcrumbs *b);
 
+static inline struct intel_breadcrumbs *
+intel_breadcrumbs_get(struct intel_breadcrumbs *b)
+{
+       kref_get(&b->ref);
+       return b;
+}
+
+static inline void intel_breadcrumbs_put(struct intel_breadcrumbs *b)
+{
+       kref_put(&b->ref, intel_breadcrumbs_free);
+}
+
 #endif /* __INTEL_BREADCRUMBS__ */

diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs_types.h b/drivers/gpu/drm/i915/gt/intel_breadcrumbs_types.h
index 3a084ce..72dfd37 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs_types.h
@@ -7,10 +7,13 @@
 #define __INTEL_BREADCRUMBS_TYPES__
 
 #include <linux/irq_work.h>
+#include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
+#include "intel_engine_types.h"
+
 /*
  * Rather than have every client wait upon all user interrupts,
  * with the herd waking after every interrupt and each doing the
@@ -29,6 +32,7 @@
  * the overhead of waking that client is much preferred.
  */
 struct intel_breadcrumbs {
+       struct kref ref;
        atomic_t active;
 
        spinlock_t signalers_lock; /* protects the list of signalers */
@@ -42,7 +46,10 @@ struct intel_breadcrumbs {
        bool irq_armed;
 
        /* Not all breadcrumbs are attached to physical HW */
+       intel_engine_mask_t     engine_mask;
        struct intel_engine_cs *irq_engine;
+       bool    (*irq_enable)(struct intel_breadcrumbs *b);
+       void    (*irq_disable)(struct intel_breadcrumbs *b);
 };
 
 #endif /* __INTEL_BREADCRUMBS_TYPES__ */

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 13bfb7e..8fc76dc 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -212,6 +212,9 @@ void intel_engine_get_instdone(const struct intel_engine_cs *engine,
 
 void intel_engine_init_execlists(struct intel_engine_cs *engine);
 
+bool intel_engine_irq_enable(struct intel_engine_cs *engine);
+void intel_engine_irq_disable(struct intel_engine_cs *engine);
+
 static inline void __intel_engine_reset(struct intel_engine_cs *engine,
                                        bool stalled)
 {

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 6a7edc8..1eaa658 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -798,7 +798,7 @@ static int engine_setup_common(struct intel_engine_cs *engine)
 err_cmd_parser:
        i915_sched_engine_put(engine->sched_engine);
 err_sched_engine:
-       intel_breadcrumbs_free(engine->breadcrumbs);
+       intel_breadcrumbs_put(engine->breadcrumbs);
 err_status:
        cleanup_status_page(engine);
        return err;
@@ -1007,7 +1007,7 @@ void intel_engine_cleanup_common(struct intel_engine_cs *engine)
        GEM_BUG_ON(!list_empty(&engine->sched_engine->requests));
 
        i915_sched_engine_put(engine->sched_engine);
-       intel_breadcrumbs_free(engine->breadcrumbs);
+       intel_breadcrumbs_put(engine->breadcrumbs);
 
        intel_engine_fini_retire(engine);
        intel_engine_cleanup_cmd_parser(engine);
@@ -1324,6 +1324,30 @@ bool intel_engines_are_idle(struct intel_gt *gt)
        return true;
 }
 
+bool intel_engine_irq_enable(struct intel_engine_cs *engine)
+{
+       if (!engine->irq_enable)
+               return false;
+
+       /* Caller disables interrupts */
+       spin_lock(&engine->gt->irq_lock);
+       engine->irq_enable(engine);
+       spin_unlock(&engine->gt->irq_lock);
+
+       return true;
+}
+
+void intel_engine_irq_disable(struct intel_engine_cs *engine)
+{
+       if (!engine->irq_disable)
+               return;
+
+       /* Caller disables interrupts */
+       spin_lock(&engine->gt->irq_lock);
+       engine->irq_disable(engine);
+       spin_unlock(&engine->gt->irq_lock);
+}
+
 void intel_engines_reset_default_submission(struct intel_gt *gt)
 {
        struct intel_engine_cs *engine;

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
index 75a34cd..e55776e 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
@@ -21,7 +21,6 @@
 #include "i915_pmu.h"
 #include "i915_priolist_types.h"
 #include "i915_selftest.h"
-#include "intel_breadcrumbs_types.h"
 #include "intel_sseu.h"
 #include "intel_timeline_types.h"
 #include "intel_uncore.h"
@@ -52,6 +51,7 @@ struct i915_sched_engine;
 struct intel_gt;
 struct intel_ring;
 struct intel_uncore;
+struct intel_breadcrumbs;
 
 typedef u32 intel_engine_mask_t;
 #define ALL_ENGINES ((intel_engine_mask_t)~0ul)

diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 1e76768..6e4959e 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -3457,7 +3457,7 @@ static void rcu_virtual_context_destroy(struct work_struct *wrk)
        intel_context_fini(&ve->context);
 
        if (ve->base.breadcrumbs)
-               intel_breadcrumbs_free(ve->base.breadcrumbs);
+               intel_breadcrumbs_put(ve->base.breadcrumbs);
        if (ve->base.sched_engine)
                i915_sched_engine_put(ve->base.sched_engine);
        intel_engine_free_request_pool(&ve->base);

diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
index 6897039..2ddaacb 100644 (file)
--- a/drivers/gpu/drm/i915/gt/mock_engine.c
+++ b/drivers/gpu/drm/i915/gt/mock_engine.c
@@ -284,7 +284,7 @@ static void mock_engine_release(struct intel_engine_cs *engine)
        GEM_BUG_ON(timer_pending(&mock->hw_delay));
 
        i915_sched_engine_put(engine->sched_engine);
-       intel_breadcrumbs_free(engine->breadcrumbs);
+       intel_breadcrumbs_put(engine->breadcrumbs);
 
        intel_context_unpin(engine->kernel_context);
        intel_context_put(engine->kernel_context);
@@ -370,7 +370,7 @@ int mock_engine_init(struct intel_engine_cs *engine)
        return 0;
 
 err_breadcrumbs:
-       intel_breadcrumbs_free(engine->breadcrumbs);
+       intel_breadcrumbs_put(engine->breadcrumbs);
 err_schedule:
        i915_sched_engine_put(engine->sched_engine);
        return -ENOMEM;

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 6b08221..60a73d9 100644 (file)
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1087,6 +1087,9 @@ static void __guc_context_destroy(struct intel_context *ce)
                struct guc_virtual_engine *ve =
                        container_of(ce, typeof(*ve), context);
 
+               if (ve->base.breadcrumbs)
+                       intel_breadcrumbs_put(ve->base.breadcrumbs);
+
                kfree(ve);
        } else {
                intel_context_free(ce);
@@ -1378,6 +1381,62 @@ static const struct intel_context_ops virtual_guc_context_ops = {
        .get_sibling = guc_virtual_get_sibling,
 };
 
+static bool
+guc_irq_enable_breadcrumbs(struct intel_breadcrumbs *b)
+{
+       struct intel_engine_cs *sibling;
+       intel_engine_mask_t tmp, mask = b->engine_mask;
+       bool result = false;
+
+       for_each_engine_masked(sibling, b->irq_engine->gt, mask, tmp)
+               result |= intel_engine_irq_enable(sibling);
+
+       return result;
+}
+
+static void
+guc_irq_disable_breadcrumbs(struct intel_breadcrumbs *b)
+{
+       struct intel_engine_cs *sibling;
+       intel_engine_mask_t tmp, mask = b->engine_mask;
+
+       for_each_engine_masked(sibling, b->irq_engine->gt, mask, tmp)
+               intel_engine_irq_disable(sibling);
+}
+
+static void guc_init_breadcrumbs(struct intel_engine_cs *engine)
+{
+       int i;
+
+       /*
+        * In GuC submission mode we do not know which physical engine a request
+        * will be scheduled on, this creates a problem because the breadcrumb
+        * interrupt is per physical engine. To work around this we attach
+        * requests and direct all breadcrumb interrupts to the first instance
+        * of an engine per class. In addition all breadcrumb interrupts are
+        * enabled / disabled across an engine class in unison.
+        */
+       for (i = 0; i < MAX_ENGINE_INSTANCE; ++i) {
+               struct intel_engine_cs *sibling =
+                       engine->gt->engine_class[engine->class][i];
+
+               if (sibling) {
+                       if (engine->breadcrumbs != sibling->breadcrumbs) {
+                               intel_breadcrumbs_put(engine->breadcrumbs);
+                               engine->breadcrumbs =
+                                       intel_breadcrumbs_get(sibling->breadcrumbs);
+                       }
+                       break;
+               }
+       }
+
+       if (engine->breadcrumbs) {
+               engine->breadcrumbs->engine_mask |= engine->mask;
+               engine->breadcrumbs->irq_enable = guc_irq_enable_breadcrumbs;
+               engine->breadcrumbs->irq_disable = guc_irq_disable_breadcrumbs;
+       }
+}
+
 static void sanitize_hwsp(struct intel_engine_cs *engine)
 {
        struct intel_timeline *tl;
@@ -1590,6 +1649,7 @@ int intel_guc_submission_setup(struct intel_engine_cs *engine)
 
        guc_default_vfuncs(engine);
        guc_default_irqs(engine);
+       guc_init_breadcrumbs(engine);
 
        if (engine->class == RENDER_CLASS)
                rcs_submission_override(engine);
@@ -1832,11 +1892,6 @@ guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
        ve->base.instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
        ve->base.uabi_instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
        ve->base.saturated = ALL_ENGINES;
-       ve->base.breadcrumbs = intel_breadcrumbs_create(&ve->base);
-       if (!ve->base.breadcrumbs) {
-               kfree(ve);
-               return ERR_PTR(-ENOMEM);
-       }
 
        snprintf(ve->base.name, sizeof(ve->base.name), "virtual");
 
@@ -1885,6 +1940,8 @@ guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
                                sibling->emit_fini_breadcrumb;
                        ve->base.emit_fini_breadcrumb_dw =
                                sibling->emit_fini_breadcrumb_dw;
+                       ve->base.breadcrumbs =
+                               intel_breadcrumbs_get(sibling->breadcrumbs);
 
                        ve->base.flags |= sibling->flags;