drm/i915: Use explicit flag to mark unreachable intel_context

I need to keep the GEM context around a bit longer so adding an explicit
flag for syncing execbuf with closed/abandonded contexts.

v2:
 * Use already available context flags. (Chris)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200319170707.8262-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index c0e476f..50e7580 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -574,7 +574,7 @@ static void engines_idle_release(struct i915_gem_context *ctx,
                int err = 0;
 
                /* serialises with execbuf */
-               RCU_INIT_POINTER(ce->gem_context, NULL);
+               set_bit(CONTEXT_CLOSED_BIT, &ce->flags);
                if (!intel_context_pin_if_active(ce))
                        continue;
 

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index d3f4f28..36d0695 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -2316,7 +2316,7 @@ static void eb_request_add(struct i915_execbuffer *eb)
        prev = __i915_request_commit(rq);
 
        /* Check that the context wasn't destroyed before submission */
-       if (likely(rcu_access_pointer(eb->context->gem_context))) {
+       if (likely(!intel_context_is_closed(eb->context))) {
                attr = eb->gem_context->sched;
 
                /*

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 01474d3..aea992e 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -97,6 +97,8 @@ int __intel_context_do_pin(struct intel_context *ce)
 {
        int err;
 
+       GEM_BUG_ON(intel_context_is_closed(ce));
+
        if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
                err = intel_context_alloc_state(ce);
                if (err)

diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
index 18efad2..07be021 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -173,6 +173,11 @@ static inline bool intel_context_is_barrier(const struct intel_context *ce)
        return test_bit(CONTEXT_BARRIER_BIT, &ce->flags);
 }
 
+static inline bool intel_context_is_closed(const struct intel_context *ce)
+{
+       return test_bit(CONTEXT_CLOSED_BIT, &ce->flags);
+}
+
 static inline bool intel_context_use_semaphores(const struct intel_context *ce)
 {
        return test_bit(CONTEXT_USE_SEMAPHORES, &ce->flags);

diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 0f3b68b..07cb83a 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -62,10 +62,11 @@ struct intel_context {
 #define CONTEXT_BARRIER_BIT            0
 #define CONTEXT_ALLOC_BIT              1
 #define CONTEXT_VALID_BIT              2
-#define CONTEXT_USE_SEMAPHORES         3
-#define CONTEXT_BANNED                 4
-#define CONTEXT_FORCE_SINGLE_SUBMISSION        5
-#define CONTEXT_NOPREEMPT              6
+#define CONTEXT_CLOSED_BIT             3
+#define CONTEXT_USE_SEMAPHORES         4
+#define CONTEXT_BANNED                 5
+#define CONTEXT_FORCE_SINGLE_SUBMISSION        6
+#define CONTEXT_NOPREEMPT              7
 
        u32 *lrc_reg_state;
        u64 lrc_desc;