From: Michel Thierry <michel.thie...@intel.com>

Emit the required commands into the ring buffer for starting and
stopping the watchdog timer before/after batch buffer start during
batch buffer submission.

v2: Support watchdog threshold per context engine, merge lri commands,
and move watchdog commands emission to emit_bb_start. Request space of
combined start_watchdog, bb_start and stop_watchdog to avoid any error
after emitting bb_start.

v3: There were too many req->engine in emit_bb_start.
Use GEM_BUG_ON instead of returning a very late EINVAL in the remote
case of watchdog misprogramming; set correct LRI cmd size in
emit_stop_watchdog. (Chris)

v4: Rebase.
v5: use to_intel_context instead of ctx->engine.
v6: Rebase.
v7: Rebase,
    Store gpu watchdog capability in engine flag (Tvrtko)
    Store WATCHDOG_DISABLE magic # in engine (Tvrtko)
    No need to declare emit_{start|stop}_watchdog as vfuncs (Tvrtko)
    Replace flag watchdog_running with enable_watchdog (Tvrtko)
    Emit a single MI_NOOP by conditionally checking whether the #
    of emitted OPs is odd (Tvrtko)
v8: Rebase

Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Antonio Argenziano <antonio.argenzi...@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursu...@linux.intel.com>
Signed-off-by: Michel Thierry <michel.thie...@intel.com>
Signed-off-by: Carlos Santa <carlos.sa...@intel.com>
---
 drivers/gpu/drm/i915/intel_context_types.h |  4 +
 drivers/gpu/drm/i915/intel_engine_cs.c     |  2 +
 drivers/gpu/drm/i915/intel_engine_types.h  | 17 ++++-
 drivers/gpu/drm/i915/intel_lrc.c           | 89 +++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_lrc.h           |  2 +
 5 files changed, 106 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_context_types.h 
b/drivers/gpu/drm/i915/intel_context_types.h
index 6dc9b4b9067b..e56fc263568e 100644
--- a/drivers/gpu/drm/i915/intel_context_types.h
+++ b/drivers/gpu/drm/i915/intel_context_types.h
@@ -51,6 +51,10 @@ struct intel_context {
        u64 lrc_desc;
 
        atomic_t pin_count;
+       /** watchdog_threshold: hw watchdog threshold value,
+        * in clock counts
+        */
+       u32 watchdog_threshold;
        struct mutex pin_mutex; /* guards pinning and associated on-gpuing */
 
        /**
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c 
b/drivers/gpu/drm/i915/intel_engine_cs.c
index 88cf0fc07623..d4ea07b70904 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -324,6 +324,8 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
        if (engine->context_size)
                DRIVER_CAPS(dev_priv)->has_logical_contexts = true;
 
+       engine->watchdog_disable_id = get_watchdog_disable(engine);
+
        /* Nothing to do here, execute in order of dependencies */
        engine->schedule = NULL;
 
diff --git a/drivers/gpu/drm/i915/intel_engine_types.h 
b/drivers/gpu/drm/i915/intel_engine_types.h
index c4f66b774e7c..1f99b536471d 100644
--- a/drivers/gpu/drm/i915/intel_engine_types.h
+++ b/drivers/gpu/drm/i915/intel_engine_types.h
@@ -260,6 +260,7 @@ struct intel_engine_cs {
        unsigned int guc_id;
        intel_engine_mask_t mask;
 
+       u32 watchdog_disable_id;
        u8 uabi_class;
 
        u8 class;
@@ -422,10 +423,12 @@ struct intel_engine_cs {
 
        struct intel_engine_hangcheck hangcheck;
 
-#define I915_ENGINE_NEEDS_CMD_PARSER BIT(0)
-#define I915_ENGINE_SUPPORTS_STATS   BIT(1)
-#define I915_ENGINE_HAS_PREEMPTION   BIT(2)
-#define I915_ENGINE_HAS_SEMAPHORES   BIT(3)
+#define I915_ENGINE_NEEDS_CMD_PARSER  BIT(0)
+#define I915_ENGINE_SUPPORTS_STATS    BIT(1)
+#define I915_ENGINE_HAS_PREEMPTION    BIT(2)
+#define I915_ENGINE_HAS_SEMAPHORES    BIT(3)
+#define I915_ENGINE_SUPPORTS_WATCHDOG BIT(4)
+
        unsigned int flags;
 
        /*
@@ -509,6 +512,12 @@ intel_engine_has_semaphores(const struct intel_engine_cs 
*engine)
        return engine->flags & I915_ENGINE_HAS_SEMAPHORES;
 }
 
+static inline bool
+intel_engine_supports_watchdog(const struct intel_engine_cs *engine)
+{
+       return engine->flags & I915_ENGINE_SUPPORTS_WATCHDOG;
+}
+
 #define instdone_slice_mask(dev_priv__) \
        (IS_GEN(dev_priv__, 7) ? \
         1 : RUNTIME_INFO(dev_priv__)->sseu.slice_mask)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 85785a94f6ae..78ea54a5dbc3 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2036,16 +2036,75 @@ static void execlists_reset_finish(struct 
intel_engine_cs *engine)
                  atomic_read(&execlists->tasklet.count));
 }
 
+static u32 *gen8_emit_start_watchdog(struct i915_request *rq, u32 *cs)
+{
+       struct intel_engine_cs *engine = rq->engine;
+       struct i915_gem_context *ctx = rq->gem_context;
+       struct intel_context *ce = intel_context_lookup(ctx, engine);
+
+       GEM_BUG_ON(!intel_engine_supports_watchdog(engine));
+
+       /*
+        * watchdog register must never be programmed to zero. This would
+        * cause the watchdog counter to exceed and not allow the engine to
+        * go into IDLE state
+        */
+       GEM_BUG_ON(ce->watchdog_threshold == 0);
+
+       /* Set counter period */
+       *cs++ = MI_LOAD_REGISTER_IMM(2);
+       *cs++ = i915_mmio_reg_offset(RING_THRESH(engine->mmio_base));
+       *cs++ = ce->watchdog_threshold;
+       /* Start counter */
+       *cs++ = i915_mmio_reg_offset(RING_CNTR(engine->mmio_base));
+       *cs++ = GEN8_WATCHDOG_ENABLE;
+
+       return cs;
+}
+
+static u32 *gen8_emit_stop_watchdog(struct i915_request *rq, u32 *cs)
+{
+       struct intel_engine_cs *engine = rq->engine;
+
+       GEM_BUG_ON(!intel_engine_supports_watchdog(engine));
+
+       *cs++ = MI_LOAD_REGISTER_IMM(1);
+       *cs++ = i915_mmio_reg_offset(RING_CNTR(engine->mmio_base));
+       *cs++ = engine->watchdog_disable_id;
+
+       return cs;
+}
+
 static int gen8_emit_bb_start(struct i915_request *rq,
                              u64 offset, u32 len,
                              const unsigned int flags)
 {
+       struct intel_engine_cs *engine = rq->engine;
+       struct i915_gem_context *ctx = rq->gem_context;
+       struct intel_context *ce = intel_context_lookup(ctx, engine);
        u32 *cs;
+       u32 num_dwords;
+       bool enable_watchdog = false;
 
-       cs = intel_ring_begin(rq, 6);
+       /* bb_start only */
+       num_dwords = 6;
+
+       /* check if watchdog will be required */
+       if (ce->watchdog_threshold != 0) {
+               /* + start_watchdog (6) + stop_watchdog (4) */
+               num_dwords += 10;
+               enable_watchdog = true;
+       }
+
+       cs = intel_ring_begin(rq, num_dwords);
        if (IS_ERR(cs))
                return PTR_ERR(cs);
 
+       if (enable_watchdog) {
+               /* Start watchdog timer */
+               cs = gen8_emit_start_watchdog(rq, cs);
+       }
+
        /*
         * WaDisableCtxRestoreArbitration:bdw,chv
         *
@@ -2072,10 +2131,16 @@ static int gen8_emit_bb_start(struct i915_request *rq,
        *cs++ = upper_32_bits(offset);
 
        *cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
-       *cs++ = MI_NOOP;
 
-       intel_ring_advance(rq, cs);
+       if (enable_watchdog) {
+               /* Cancel watchdog timer */
+               cs = gen8_emit_stop_watchdog(rq, cs);
+       }
+
+       if (*cs%2 != 0)
+               *cs++ = MI_NOOP;
 
+       intel_ring_advance(rq, cs);
        return 0;
 }
 
@@ -2195,6 +2260,15 @@ static int gen8_emit_flush_render(struct i915_request 
*request,
        return 0;
 }
 
+/* From GEN9 onwards, all engines use the same RING_CNTR format */
+u32 get_watchdog_disable(struct intel_engine_cs *engine)
+{
+       if (engine->id == RCS0 || INTEL_GEN(engine->i915) >= 9)
+               return GEN8_WATCHDOG_DISABLE;
+       else
+               return GEN8_XCS_WATCHDOG_DISABLE;
+}
+
 static void gen8_watchdog_tasklet(unsigned long data)
 {
        struct intel_engine_cs *engine = (struct intel_engine_cs *)data;
@@ -2357,6 +2431,9 @@ void intel_execlists_set_default_submission(struct 
intel_engine_cs *engine)
        engine->flags |= I915_ENGINE_SUPPORTS_STATS;
        if (engine->preempt_context)
                engine->flags |= I915_ENGINE_HAS_PREEMPTION;
+
+       if(engine->id != BCS0)
+               engine->flags |= I915_ENGINE_SUPPORTS_WATCHDOG;
 }
 
 static void
@@ -2531,6 +2608,9 @@ int logical_xcs_ring_init(struct intel_engine_cs *engine)
        if (err)
                return err;
 
+       /* BCS engine does not have a watchdog-expired irq */
+       GEM_BUG_ON(!intel_engine_supports_watchdog(engine));
+
        return logical_ring_init(engine);
 }
 
@@ -2666,7 +2746,7 @@ u32 gen8_make_rpcs(struct drm_i915_private *i915, struct 
intel_sseu *req_sseu)
        return rpcs;
 }
 
-static u32 intel_lr_indirect_ctx_offset(struct intel_engine_cs *engine)
+u32 intel_lr_indirect_ctx_offset(struct intel_engine_cs *engine)
 {
        u32 indirect_ctx_offset;
 
@@ -2693,6 +2773,7 @@ static u32 intel_lr_indirect_ctx_offset(struct 
intel_engine_cs *engine)
        }
 
        return indirect_ctx_offset;
+
 }
 
 static void execlists_init_reg_state(u32 *regs,
diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
index f1aec8a6986f..4ce97fd5bb2e 100644
--- a/drivers/gpu/drm/i915/intel_lrc.h
+++ b/drivers/gpu/drm/i915/intel_lrc.h
@@ -114,4 +114,6 @@ void intel_execlists_show_requests(struct intel_engine_cs 
*engine,
 
 u32 gen8_make_rpcs(struct drm_i915_private *i915, struct intel_sseu *ctx_sseu);
 
+u32 get_watchdog_disable(struct intel_engine_cs *engine);
+
 #endif /* _INTEL_LRC_H_ */
-- 
2.17.1

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