[Intel-gfx] [PATCH 23/51] drm/i915/guc: Direct all breadcrumbs for a class to single breadcrumbs

Matthew Brost
2021-07-16T20:00:31Z

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>
---
drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 41 +++++-------
drivers/gpu/drm/i915/gt/intel_breadcrumbs.h | 16 ++++-
.../gpu/drm/i915/gt/intel_breadcrumbs_types.h | 7 ++
drivers/gpu/drm/i915/gt/intel_engine.h | 3 +
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 28 +++++++-
drivers/gpu/drm/i915/gt/intel_engine_types.h | 2 +-
.../drm/i915/gt/intel_execlists_submission.c | 2 +-
drivers/gpu/drm/i915/gt/mock_engine.c | 4 +-
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 67 +++++++++++++++++--
9 files changed, 133 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
index 38cc42783dfb..2007dc6f6b99 100644
--- 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 3ce5ce270b04..be0d4f379a85 100644
--- 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 3a084ce8ff5e..72dfd3748c4c 100644
--- 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 9fec0aca5f4b..edbde6171bca 100644
--- 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 b7292d5cb7da..d95d666407f5 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -739,7 +739,7 @@ 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;
@@ -948,7 +948,7 @@ 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);
@@ -1265,6 +1265,30 @@ 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 8ad304b2f2e4..03a81e8d87f4 100644
--- 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"
@@ -63,6 +62,7 @@ struct i915_sched_engine;
struct intel_gt;
struct intel_ring;
struct intel_uncore;
+struct intel_breadcrumbs;

typedef u8 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 920707e22eb0..abe48421fd7a 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -3407,7 +3407,7 @@ 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 9203c766db80..fc5a65ab1937 100644
--- 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);
@@ -376,7 +376,7 @@ 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 372e0dc7617a..9f28899ff17f 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -1076,6 +1076,9 @@ 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);
@@ -1366,6 +1369,62 @@ 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;
@@ -1589,6 +1648,7 @@ 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);
@@ -1831,11 +1891,6 @@ 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");

@@ -1884,6 +1939,8 @@ 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;

--
2.28.0