drm/i915: Move context management under GEM

Keep track of the GEM contexts underneath i915->gem.contexts and assign
them their own lock for the purposes of list management.

v2: Focus on lock tracking; ctx->vm is protected by ctx->mutex
v3: Correct split with removal of logical HW ID

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-15-chris@chris-wilson.co.uk

6 files changed, 20 insertions, 31 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem.c b/drivers/gpu/drm/i915/selftests/i915_gem.c
index 0346c3e5b6b6..bfa40a5b6d98 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem.c
@@ -138,11 +138,9 @@ static int igt_gem_suspend(void *arg)
 		return PTR_ERR(file);
 
 	err = -ENOMEM;
-	mutex_lock(&i915->drm.struct_mutex);
 	ctx = live_context(i915, file);
 	if (!IS_ERR(ctx))
 		err = switch_to_context(i915, ctx);
-	mutex_unlock(&i915->drm.struct_mutex);
 	if (err)
 		goto out;
 
@@ -157,9 +155,7 @@ static int igt_gem_suspend(void *arg)
 
 	pm_resume(i915);
 
-	mutex_lock(&i915->drm.struct_mutex);
 	err = switch_to_context(i915, ctx);
-	mutex_unlock(&i915->drm.struct_mutex);
 out:
 	mock_file_free(i915, file);
 	return err;
@@ -177,11 +173,9 @@ static int igt_gem_hibernate(void *arg)
 		return PTR_ERR(file);
 
 	err = -ENOMEM;
-	mutex_lock(&i915->drm.struct_mutex);
 	ctx = live_context(i915, file);
 	if (!IS_ERR(ctx))
 		err = switch_to_context(i915, ctx);
-	mutex_unlock(&i915->drm.struct_mutex);
 	if (err)
 		goto out;
 
@@ -196,9 +190,7 @@ static int igt_gem_hibernate(void *arg)
 
 	pm_resume(i915);
 
-	mutex_lock(&i915->drm.struct_mutex);
 	err = switch_to_context(i915, ctx);
-	mutex_unlock(&i915->drm.struct_mutex);
 out:
 	mock_file_free(i915, file);
 	return err;
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
index f39f0282e78c..0af9a58d011d 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
@@ -473,7 +473,6 @@ static int igt_evict_contexts(void *arg)
 		}
 
 		count = 0;
-		mutex_lock(&i915->drm.struct_mutex);
 		onstack_fence_init(&fence);
 		do {
 			struct i915_request *rq;
@@ -510,8 +509,6 @@ static int igt_evict_contexts(void *arg)
 			count++;
 			err = 0;
 		} while(1);
-		mutex_unlock(&i915->drm.struct_mutex);
-
 		onstack_fence_fini(&fence);
 		pr_info("Submitted %lu contexts/requests on %s\n",
 			count, engine->name);
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index e40e6cfa51f1..8d8121c02161 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1246,6 +1246,7 @@ static int exercise_mock(struct drm_i915_private *i915,
 				     unsigned long end_time))
 {
 	const u64 limit = totalram_pages() << PAGE_SHIFT;
+	struct i915_address_space *vm;
 	struct i915_gem_context *ctx;
 	IGT_TIMEOUT(end_time);
 	int err;
@@ -1254,7 +1255,9 @@ static int exercise_mock(struct drm_i915_private *i915,
 	if (!ctx)
 		return -ENOMEM;
 
-	err = func(i915, ctx->vm, 0, min(ctx->vm->total, limit), end_time);
+	vm = i915_gem_context_get_vm_rcu(ctx);
+	err = func(i915, vm, 0, min(vm->total, limit), end_time);
+	i915_vm_put(vm);
 
 	mock_context_close(ctx);
 	return err;
@@ -1801,15 +1804,15 @@ static int igt_cs_tlb(void *arg)
 		goto out_unlock;
 	}
 
-	vm = ctx->vm;
-	if (!vm)
-		goto out_unlock;
+	vm = i915_gem_context_get_vm_rcu(ctx);
+	if (i915_is_ggtt(vm))
+		goto out_vm;
 
 	/* Create two pages; dummy we prefill the TLB, and intended */
 	bbe = i915_gem_object_create_internal(i915, PAGE_SIZE);
 	if (IS_ERR(bbe)) {
 		err = PTR_ERR(bbe);
-		goto out_unlock;
+		goto out_vm;
 	}
 
 	batch = i915_gem_object_pin_map(bbe, I915_MAP_WC);
@@ -2014,6 +2017,8 @@ out_put_act:
 	i915_gem_object_put(act);
 out_put_bbe:
 	i915_gem_object_put(bbe);
+out_vm:
+	i915_vm_put(vm);
 out_unlock:
 	mutex_unlock(&i915->drm.struct_mutex);
 	mock_file_free(i915, file);
diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index d7d68c6a6bd5..0897a7b04944 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -181,9 +181,7 @@ static int igt_request_rewind(void *arg)
 	struct intel_context *ce;
 	int err = -EINVAL;
 
-	mutex_lock(&i915->drm.struct_mutex);
 	ctx[0] = mock_context(i915, "A");
-	mutex_unlock(&i915->drm.struct_mutex);
 
 	ce = i915_gem_context_get_engine(ctx[0], RCS0);
 	GEM_BUG_ON(IS_ERR(ce));
@@ -197,9 +195,7 @@ static int igt_request_rewind(void *arg)
 	i915_request_get(request);
 	i915_request_add(request);
 
-	mutex_lock(&i915->drm.struct_mutex);
 	ctx[1] = mock_context(i915, "B");
-	mutex_unlock(&i915->drm.struct_mutex);
 
 	ce = i915_gem_context_get_engine(ctx[1], RCS0);
 	GEM_BUG_ON(IS_ERR(ce));
@@ -438,9 +434,7 @@ static int mock_breadcrumbs_smoketest(void *arg)
 	}
 
 	for (n = 0; n < t.ncontexts; n++) {
-		mutex_lock(&t.engine->i915->drm.struct_mutex);
 		t.contexts[n] = mock_context(t.engine->i915, "mock");
-		mutex_unlock(&t.engine->i915->drm.struct_mutex);
 		if (!t.contexts[n]) {
 			ret = -ENOMEM;
 			goto out_contexts;
@@ -734,9 +728,9 @@ out_batch:
 static struct i915_vma *recursive_batch(struct drm_i915_private *i915)
 {
 	struct i915_gem_context *ctx = i915->kernel_context;
-	struct i915_address_space *vm = ctx->vm ?: &i915->ggtt.vm;
 	struct drm_i915_gem_object *obj;
 	const int gen = INTEL_GEN(i915);
+	struct i915_address_space *vm;
 	struct i915_vma *vma;
 	u32 *cmd;
 	int err;
@@ -745,7 +739,9 @@ static struct i915_vma *recursive_batch(struct drm_i915_private *i915)
 	if (IS_ERR(obj))
 		return ERR_CAST(obj);
 
+	vm = i915_gem_context_get_vm_rcu(ctx);
 	vma = i915_vma_instance(obj, vm, NULL);
+	i915_vm_put(vm);
 	if (IS_ERR(vma)) {
 		err = PTR_ERR(vma);
 		goto err;
@@ -1220,9 +1216,7 @@ static int live_breadcrumbs_smoketest(void *arg)
 	}
 
 	for (n = 0; n < t[0].ncontexts; n++) {
-		mutex_lock(&i915->drm.struct_mutex);
 		t[0].contexts[n] = live_context(i915, file);
-		mutex_unlock(&i915->drm.struct_mutex);
 		if (!t[0].contexts[n]) {
 			ret = -ENOMEM;
 			goto out_contexts;
diff --git a/drivers/gpu/drm/i915/selftests/i915_vma.c b/drivers/gpu/drm/i915/selftests/i915_vma.c
index ac1ff558eb90..58b5f40a07dd 100644
--- a/drivers/gpu/drm/i915/selftests/i915_vma.c
+++ b/drivers/gpu/drm/i915/selftests/i915_vma.c
@@ -24,6 +24,7 @@
 
 #include <linux/prime_numbers.h>
 
+#include "gem/i915_gem_context.h"
 #include "gem/selftests/mock_context.h"
 
 #include "i915_scatterlist.h"
@@ -38,7 +39,7 @@ static bool assert_vma(struct i915_vma *vma,
 {
 	bool ok = true;
 
-	if (vma->vm != ctx->vm) {
+	if (vma->vm != rcu_access_pointer(ctx->vm)) {
 		pr_err("VMA created with wrong VM\n");
 		ok = false;
 	}
@@ -113,11 +114,13 @@ static int create_vmas(struct drm_i915_private *i915,
 	list_for_each_entry(obj, objects, st_link) {
 		for (pinned = 0; pinned <= 1; pinned++) {
 			list_for_each_entry(ctx, contexts, link) {
-				struct i915_address_space *vm = ctx->vm;
+				struct i915_address_space *vm;
 				struct i915_vma *vma;
 				int err;
 
+				vm = i915_gem_context_get_vm_rcu(ctx);
 				vma = checked_vma_instance(obj, vm, NULL);
+				i915_vm_put(vm);
 				if (IS_ERR(vma))
 					return PTR_ERR(vma);
 
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index 4e6cde0d4859..335f37ba98de 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -59,11 +59,9 @@ static void mock_device_release(struct drm_device *dev)
 
 	i915_gem_drain_workqueue(i915);
 
-	mutex_lock(&i915->drm.struct_mutex);
 	for_each_engine(engine, i915, id)
 		mock_engine_free(engine);
-	i915_gem_contexts_fini(i915);
-	mutex_unlock(&i915->drm.struct_mutex);
+	i915_gem_driver_release__contexts(i915);
 
 	intel_timelines_fini(i915);
 
@@ -206,7 +204,7 @@ struct drm_i915_private *mock_gem_device(void)
 	return i915;
 
 err_context:
-	i915_gem_contexts_fini(i915);
+	i915_gem_driver_release__contexts(i915);
 err_engine:
 	mock_engine_free(i915->engine[RCS0]);
 err_unlock: