drm/i915: Introduce execlist context status change notification

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.

v10:

- Fix the identation. (Joonas)

v8:

- Remove the boolean flag in struct i915_gem_context. (Joonas)

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)

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v8)
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-8-git-send-email-zhi.a.wang@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Zhi Wang 2016-06-16 08:07:03 -04:00 committed by Chris Wilson
parent c01fc53229
commit 3c7ba6359d
4 changed files with 29 additions and 0 deletions

View File

@ -882,6 +882,7 @@ struct i915_gem_context {
} engine[I915_NUM_ENGINES];
u32 ring_size;
u32 desc_template;
struct atomic_notifier_head status_notifier;
struct list_head link;

View File

@ -298,6 +298,7 @@ __create_hw_context(struct drm_device *dev,
ctx->ring_size = 4 * PAGE_SIZE;
ctx->desc_template = GEN8_CTX_ADDRESSING_MODE(dev_priv) <<
GEN8_CTX_ADDRESSING_MODE_SHIFT;
ATOMIC_INIT_NOTIFIER_HEAD(&ctx->status_notifier);
return ctx;

View File

@ -404,6 +404,20 @@ 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;
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 +453,12 @@ 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 +497,8 @@ 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);

View File

@ -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);