drm/i915: Record the default hw state after reset upon load
Take a copy of the HW state after a reset upon module loading by
executing a context switch from a blank context to the kernel context,
thus saving the default hw state over the blank context image.
We can then use the default hw state to initialise any future context,
ensuring that each starts with the default view of hw state.
v2: Unmap our default state from the GTT after stealing it from the
context. This should stop us from accidentally overwriting it via the
GTT (and frees up some precious GTT space).
Testcase: igt/gem_ctx_isolation
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171110142634.10551-7-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 6d0b381..868c07a 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -687,6 +687,9 @@ void intel_engine_cleanup_common(struct intel_engine_cs *engine)
intel_engine_cleanup_cmd_parser(engine);
i915_gem_batch_pool_fini(&engine->batch_pool);
+ if (engine->default_state)
+ i915_gem_object_put(engine->default_state);
+
if (HAS_LOGICAL_RING_PREEMPTION(engine->i915))
engine->context_unpin(engine, engine->i915->preempt_context);
engine->context_unpin(engine, engine->i915->kernel_context);
@@ -1705,6 +1708,20 @@ bool intel_engine_can_store_dword(struct intel_engine_cs *engine)
}
}
+unsigned int intel_engines_has_context_isolation(struct drm_i915_private *i915)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ unsigned int which;
+
+ which = 0;
+ for_each_engine(engine, i915, id)
+ if (engine->default_state)
+ which |= BIT(engine->uabi_class);
+
+ return which;
+}
+
static void print_request(struct drm_printer *m,
struct drm_i915_gem_request *rq,
const char *prefix)