This patch introduces an approach to track the execlist context status
change.
GVT-g uses GVT context as the "shadow context". The content inside GVT
context will be copied back to guest after the context is idle. And GVT-g
has to know the status of the execlist context.
This function is configurable when creating a new GEM context. Currently,
Only GVT-g will create the "status-change-notification" enabled GEM
context.
v7:
- Remove per-engine ctx status notifiers. Use one status notifier for all
engines. (Joonas)
- Add prefix "INTEL_" for related definitions. (Joonas)
- Refine the comments in execlists_context_status_change(). (Joonas)
v6:
- When !CONFIG_DRM_I915_GVT, make GVT code as dead code then compiler
could automatically eliminate them for us. (Chris)
- Always initialize the notifier header, so it could be switched on/off
at runtime. (Chris)
v5:
- Only compile this feature when CONFIG_DRM_I915_GVT is enabled.(Tvrtko)
Signed-off-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.h | 2 ++
drivers/gpu/drm/i915/i915_gem_context.c | 1 +
drivers/gpu/drm/i915/intel_lrc.c | 25 +++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_lrc.h | 5 +++++
4 files changed, 33 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a3ef3eb..4ab4cf7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -880,6 +880,8 @@ struct i915_gem_context {
} engine[I915_NUM_ENGINES];
u32 lrc_ring_buffer_size;
u32 lrc_addressing_mode_bits;
+ struct atomic_notifier_head status_notifier;
+ bool enable_lrc_status_change_notification;
struct list_head link;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index d9d7779..b0e82a1 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -298,6 +298,7 @@ __create_hw_context(struct drm_device *dev,
ctx->lrc_ring_buffer_size = 4 * PAGE_SIZE;
ctx->lrc_addressing_mode_bits = GEN8_CTX_ADDRESSING_MODE(dev_priv) <<
GEN8_CTX_ADDRESSING_MODE_SHIFT;
+ ATOMIC_INIT_NOTIFIER_HEAD(&ctx->status_notifier);
return ctx;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index ffb436c..956585d 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -404,6 +404,23 @@ static void execlists_submit_requests(struct drm_i915_gem_request *rq0,
spin_unlock_irq(&dev_priv->uncore.lock);
}
+static inline void execlists_context_status_change(
+ struct drm_i915_gem_request *rq,
+ unsigned long status)
+{
+ /*
+ * Only used when GVT-g is enabled now. When GVT-g is disabled,
+ * The compiler should eliminate this function as dead-code.
+ */
+ if (!IS_ENABLED(CONFIG_DRM_I915_GVT))
+ return;
+
+ if (!rq->ctx->enable_lrc_status_change_notification)
+ return;
+
+ atomic_notifier_call_chain(&rq->ctx->status_notifier, status, rq);
+}
+
static void execlists_context_unqueue(struct intel_engine_cs *engine)
{
struct drm_i915_gem_request *req0 = NULL, *req1 = NULL;
@@ -439,6 +456,12 @@ static void execlists_context_unqueue(struct intel_engine_cs *engine)
if (unlikely(!req0))
return;
+ execlists_context_status_change(req0, INTEL_CONTEXT_SCHEDULE_IN);
+
+ if (req1)
+ execlists_context_status_change(req1,
+ INTEL_CONTEXT_SCHEDULE_IN);
+
if (req0->elsp_submitted & engine->idle_lite_restore_wa) {
/*
* WaIdleLiteRestore: make sure we never cause a lite restore
@@ -477,6 +500,8 @@ execlists_check_remove_request(struct intel_engine_cs *engine, u32 ctx_id)
if (--head_req->elsp_submitted > 0)
return 0;
+ execlists_context_status_change(head_req, INTEL_CONTEXT_SCHEDULE_OUT);
+
list_del(&head_req->execlist_link);
i915_gem_request_unreference(head_req);
diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h
index a8db42a..2b8255c 100644
--- a/drivers/gpu/drm/i915/intel_lrc.h
+++ b/drivers/gpu/drm/i915/intel_lrc.h
@@ -57,6 +57,11 @@
#define GEN8_CSB_READ_PTR(csb_status) \
(((csb_status) & GEN8_CSB_READ_PTR_MASK) >> 8)
+enum {
+ INTEL_CONTEXT_SCHEDULE_IN = 0,
+ INTEL_CONTEXT_SCHEDULE_OUT,
+};
+
/* Logical Rings */
int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request);
int intel_logical_ring_reserve_space(struct drm_i915_gem_request *request);
--
1.9.1
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