drm/i915: Markup paired operations on wakerefs

The majority of runtime-pm operations are bounded and scoped within a
function; these are easy to verify that the wakeref are handled
correctly. We can employ the compiler to help us, and reduce the number
of wakerefs tracked when debugging, by passing around cookies provided
by the various rpm_get functions to their rpm_put counterpart. This
makes the pairing explicit, and given the required wakeref cookie the
compiler can verify that we pass an initialised value to the rpm_put
(quite handy for double checking error paths).

For regular builds, the compiler should be able to eliminate the unused
local variables and the program growth should be minimal. Fwiw, it came
out as a net improvement as gcc was able to refactor rpm_get and
rpm_get_if_in_use together,

v2: Just s/rpm_put/rpm_put_unchecked/ everywhere, leaving the manual
mark up for smaller more targeted patches.
v3: Mention the cookie in Returns

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-2-chris@chris-wilson.co.uk

12 files changed, 37 insertions, 37 deletions

diff --git a/drivers/gpu/drm/i915/selftests/huge_pages.c b/drivers/gpu/drm/i915/selftests/huge_pages.c
index 6c10734e948d..a4d8b12be12c 100644
--- a/drivers/gpu/drm/i915/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/selftests/huge_pages.c
@@ -1785,7 +1785,7 @@ int i915_gem_huge_page_live_selftests(struct drm_i915_private *dev_priv)
 	err = i915_subtests(tests, ctx);
 
 out_unlock:
-	intel_runtime_pm_put(dev_priv);
+	intel_runtime_pm_put_unchecked(dev_priv);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
 	mock_file_free(dev_priv, file);
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem.c b/drivers/gpu/drm/i915/selftests/i915_gem.c
index bdcc53e15e75..762e1a7125f5 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem.c
@@ -32,7 +32,7 @@ static int switch_to_context(struct drm_i915_private *i915,
 		i915_request_add(rq);
 	}
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 
 	return err;
 }
@@ -76,7 +76,7 @@ static void simulate_hibernate(struct drm_i915_private *i915)
 	 */
 	trash_stolen(i915);
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 }
 
 static int pm_prepare(struct drm_i915_private *i915)
@@ -98,7 +98,7 @@ static void pm_suspend(struct drm_i915_private *i915)
 	i915_gem_suspend_gtt_mappings(i915);
 	i915_gem_suspend_late(i915);
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 }
 
 static void pm_hibernate(struct drm_i915_private *i915)
@@ -110,7 +110,7 @@ static void pm_hibernate(struct drm_i915_private *i915)
 	i915_gem_freeze(i915);
 	i915_gem_freeze_late(i915);
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 }
 
 static void pm_resume(struct drm_i915_private *i915)
@@ -125,7 +125,7 @@ static void pm_resume(struct drm_i915_private *i915)
 	i915_gem_sanitize(i915);
 	i915_gem_resume(i915);
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 }
 
 static int igt_gem_suspend(void *arg)
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
index f7392c1ffe75..eea4fc2445ae 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_coherency.c
@@ -376,7 +376,7 @@ static int igt_gem_coherency(void *arg)
 		}
 	}
 unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	kfree(offsets);
 	return err;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
index d00cdf3c2939..6e1a0711d201 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_context.c
@@ -243,7 +243,7 @@ static int live_nop_switch(void *arg)
 	}
 
 out_unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	mock_file_free(i915, file);
 	return err;
@@ -609,7 +609,7 @@ static int igt_ctx_exec(void *arg)
 
 			intel_runtime_pm_get(i915);
 			err = gpu_fill(obj, ctx, engine, dw);
-			intel_runtime_pm_put(i915);
+			intel_runtime_pm_put_unchecked(i915);
 			if (err) {
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) in ctx %u [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
@@ -715,7 +715,7 @@ static int igt_ctx_readonly(void *arg)
 
 			intel_runtime_pm_get(i915);
 			err = gpu_fill(obj, ctx, engine, dw);
-			intel_runtime_pm_put(i915);
+			intel_runtime_pm_put_unchecked(i915);
 			if (err) {
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) in ctx %u [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
@@ -1067,7 +1067,7 @@ static int igt_vm_isolation(void *arg)
 		count, RUNTIME_INFO(i915)->num_rings);
 
 out_rpm:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 out_unlock:
 	if (end_live_test(&t))
 		err = -EIO;
@@ -1200,7 +1200,7 @@ out_unlock:
 	if (igt_flush_test(i915, I915_WAIT_LOCKED))
 		err = -EIO;
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 
 	kernel_context_close(ctx);
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
index 4365979d8222..8d22f73a9b63 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
@@ -464,7 +464,7 @@ out_locked:
 	}
 	if (drm_mm_node_allocated(&hole))
 		drm_mm_remove_node(&hole);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 
 	return err;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index a9ed0ecc94e2..87cb0602a5fc 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -295,7 +295,7 @@ static int lowlevel_hole(struct drm_i915_private *i915,
 
 			intel_runtime_pm_get(i915);
 			vm->insert_entries(vm, &mock_vma, I915_CACHE_NONE, 0);
-			intel_runtime_pm_put(i915);
+			intel_runtime_pm_put_unchecked(i915);
 		}
 		count = n;
 
@@ -1216,7 +1216,7 @@ static int igt_ggtt_page(void *arg)
 	kfree(order);
 out_remove:
 	ggtt->vm.clear_range(&ggtt->vm, tmp.start, tmp.size);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	drm_mm_remove_node(&tmp);
 out_unpin:
 	i915_gem_object_unpin_pages(obj);
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_object.c b/drivers/gpu/drm/i915/selftests/i915_gem_object.c
index be7ecb66ad11..b03890c590d7 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_object.c
@@ -444,7 +444,7 @@ next_tiling: ;
 	}
 
 out_unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	i915_gem_object_unpin_pages(obj);
 out:
@@ -508,7 +508,7 @@ static void disable_retire_worker(struct drm_i915_private *i915)
 	if (!i915->gt.active_requests++) {
 		intel_runtime_pm_get(i915);
 		i915_gem_unpark(i915);
-		intel_runtime_pm_put(i915);
+		intel_runtime_pm_put_unchecked(i915);
 	}
 	mutex_unlock(&i915->drm.struct_mutex);
 	cancel_delayed_work_sync(&i915->gt.retire_work);
@@ -590,7 +590,7 @@ static int igt_mmap_offset_exhaustion(void *arg)
 		mutex_lock(&i915->drm.struct_mutex);
 		intel_runtime_pm_get(i915);
 		err = make_obj_busy(obj);
-		intel_runtime_pm_put(i915);
+		intel_runtime_pm_put_unchecked(i915);
 		mutex_unlock(&i915->drm.struct_mutex);
 		if (err) {
 			pr_err("[loop %d] Failed to busy the object\n", loop);
diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 07e557815308..e8880cabd5c7 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -403,7 +403,7 @@ static int live_nop_request(void *arg)
 	}
 
 out_unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
@@ -553,7 +553,7 @@ out_batch:
 	i915_vma_unpin(batch);
 	i915_vma_put(batch);
 out_unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
@@ -731,7 +731,7 @@ out_request:
 	i915_vma_unpin(batch);
 	i915_vma_put(batch);
 out_unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
@@ -860,7 +860,7 @@ out_request:
 		i915_request_put(request[id]);
 	}
 out_unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
diff --git a/drivers/gpu/drm/i915/selftests/intel_guc.c b/drivers/gpu/drm/i915/selftests/intel_guc.c
index 32cba4cae31a..3590ba3d8897 100644
--- a/drivers/gpu/drm/i915/selftests/intel_guc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_guc.c
@@ -225,7 +225,7 @@ out:
 	guc_clients_create(guc);
 	guc_clients_enable(guc);
 unlock:
-	intel_runtime_pm_put(dev_priv);
+	intel_runtime_pm_put_unchecked(dev_priv);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 	return err;
 }
@@ -337,7 +337,7 @@ out:
 			guc_client_free(clients[i]);
 		}
 unlock:
-	intel_runtime_pm_put(dev_priv);
+	intel_runtime_pm_put_unchecked(dev_priv);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 	return err;
 }
diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
index 797cf5e6d6d4..58cba8188bd2 100644
--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -402,7 +402,7 @@ static int igt_wedged_reset(void *arg)
 	i915_reset(i915, ALL_ENGINES, NULL);
 	GEM_BUG_ON(test_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags));
 
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	igt_global_reset_unlock(i915);
 
@@ -1636,7 +1636,7 @@ out:
 	force_reset(i915);
 
 unlock:
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	igt_global_reset_unlock(i915);
 
@@ -1679,7 +1679,7 @@ int intel_hangcheck_live_selftests(struct drm_i915_private *i915)
 	mutex_unlock(&i915->drm.struct_mutex);
 
 	i915_modparams.enable_hangcheck = saved_hangcheck;
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 
 	return err;
 }
diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c
index 00caaa00f02f..ac1b18a17f3c 100644
--- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
@@ -65,7 +65,7 @@ err_spin:
 	igt_spinner_fini(&spin);
 err_unlock:
 	igt_flush_test(i915, I915_WAIT_LOCKED);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
@@ -158,7 +158,7 @@ err_spin_hi:
 	igt_spinner_fini(&spin_hi);
 err_unlock:
 	igt_flush_test(i915, I915_WAIT_LOCKED);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
@@ -251,7 +251,7 @@ err_spin_hi:
 	igt_spinner_fini(&spin_hi);
 err_unlock:
 	igt_flush_test(i915, I915_WAIT_LOCKED);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 
@@ -374,7 +374,7 @@ err_spin_hi:
 	igt_spinner_fini(&spin_hi);
 err_unlock:
 	igt_flush_test(i915, I915_WAIT_LOCKED);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 	return err;
 }
@@ -627,7 +627,7 @@ err_ctx:
 err_batch:
 	i915_gem_object_put(smoke.batch);
 err_unlock:
-	intel_runtime_pm_put(smoke.i915);
+	intel_runtime_pm_put_unchecked(smoke.i915);
 	mutex_unlock(&smoke.i915->drm.struct_mutex);
 	kfree(smoke.contexts);
 
diff --git a/drivers/gpu/drm/i915/selftests/intel_workarounds.c b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
index 8b3f3200a3bd..b1b39c70c702 100644
--- a/drivers/gpu/drm/i915/selftests/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
@@ -94,7 +94,7 @@ read_nonprivs(struct i915_gem_context *ctx, struct intel_engine_cs *engine)
 
 	intel_runtime_pm_get(engine->i915);
 	rq = i915_request_alloc(engine, ctx);
-	intel_runtime_pm_put(engine->i915);
+	intel_runtime_pm_put_unchecked(engine->i915);
 	if (IS_ERR(rq)) {
 		err = PTR_ERR(rq);
 		goto err_pin;
@@ -241,7 +241,7 @@ switch_to_scratch_context(struct intel_engine_cs *engine,
 	else
 		rq = i915_request_alloc(engine, ctx);
 
-	intel_runtime_pm_put(engine->i915);
+	intel_runtime_pm_put_unchecked(engine->i915);
 
 	kernel_context_close(ctx);
 
@@ -300,7 +300,7 @@ static int check_whitelist_across_reset(struct intel_engine_cs *engine,
 
 	intel_runtime_pm_get(i915);
 	err = reset(engine);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 
 	if (want_spin) {
 		igt_spinner_end(&spin);
@@ -414,7 +414,7 @@ live_gpu_reset_gt_engine_workarounds(void *arg)
 
 out:
 	reference_lists_fini(i915, &lists);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	igt_global_reset_unlock(i915);
 
 	return ok ? 0 : -ESRCH;
@@ -496,7 +496,7 @@ live_engine_reset_gt_engine_workarounds(void *arg)
 
 err:
 	reference_lists_fini(i915, &lists);
-	intel_runtime_pm_put(i915);
+	intel_runtime_pm_put_unchecked(i915);
 	igt_global_reset_unlock(i915);
 	kernel_context_close(ctx);