There's quite a fundamental difference between userspace contexts, and
kernel contexts. Latter all share intel_gt->vm, former get their vm
from gem_ctx->vm (on full ppgtt at least).
By splitting context creation for userspace from kernel-internal ones
we can make this all a bit more strict and WARN_ON if there's a vm
already set in intel_context_set_gem().
All this is only possible because gem_ctx cannot chance their VM
anymore since
commit ccbc1b97948ab671335e950271e39766729736c3
Author: Jason Ekstrand <ja...@jlekstrand.net>
Date: Thu Jul 8 10:48:30 2021 -0500
drm/i915/gem: Don't allow changing the VM on running contexts (v4)
Signed-off-by: Daniel Vetter <daniel.vet...@intel.com>
Cc: Jon Bloomfield <jon.bloomfi...@intel.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahti...@linux.intel.com>
Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellst...@linux.intel.com>
Cc: Matthew Auld <matthew.a...@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwer...@intel.com>
Cc: Dave Airlie <airl...@redhat.com>
Cc: Jason Ekstrand <ja...@jlekstrand.net>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 6 ++---
.../gpu/drm/i915/gem/i915_gem_execbuffer.c | 4 +++-
.../gpu/drm/i915/gem/selftests/mock_context.c | 2 +-
drivers/gpu/drm/i915/gt/intel_context.c | 22 +++++++++++++++++--
drivers/gpu/drm/i915/gt/intel_context.h | 2 ++
5 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c
b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 2f3cc73d4710..13358e6749d9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -746,7 +746,7 @@ static int intel_context_set_gem(struct intel_context *ce,
ce->ring_size = SZ_16K;
- i915_vm_put(ce->vm);
+ WARN_ON(ce->vm);
ce->vm = i915_gem_context_get_eb_vm(ctx);
if (ctx->sched.priority >= I915_PRIORITY_NORMAL &&
@@ -856,7 +856,7 @@ static struct i915_gem_engines *default_engines(struct
i915_gem_context *ctx,
GEM_BUG_ON(engine->legacy_idx >= I915_NUM_ENGINES);
GEM_BUG_ON(e->engines[engine->legacy_idx]);
- ce = intel_context_create(engine);
+ ce = intel_context_create_user(engine);
if (IS_ERR(ce)) {
err = ERR_CAST(ce);
goto free_engines;
@@ -897,7 +897,7 @@ static struct i915_gem_engines *user_engines(struct
i915_gem_context *ctx,
switch (pe[n].type) {
case I915_GEM_ENGINE_TYPE_PHYSICAL:
- ce = intel_context_create(pe[n].engine);
+ ce = intel_context_create_user(pe[n].engine);
break;
case I915_GEM_ENGINE_TYPE_BALANCED:
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index bdf2b5785a81..54de94433365 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -30,15 +30,17 @@
struct eb_vma {
struct i915_vma *vma;
+ struct drm_i915_gem_object *obj;
unsigned int flags;
+ u32 handle;
+
/** This vma's place in the execbuf reservation list */
struct drm_i915_gem_exec_object2 *exec;
struct list_head bind_link;
struct list_head reloc_link;
struct hlist_node node;
- u32 handle;
};
enum {
diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c
b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
index fee070df1c97..e5efda1058a3 100644
--- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
@@ -124,7 +124,7 @@ live_context_for_engine(struct intel_engine_cs *engine,
struct file *file)
return ctx;
}
- ce = intel_context_create(engine);
+ ce = intel_context_create_user(engine);
if (IS_ERR(ce)) {
__free_engines(engines, 0);
return ERR_CAST(ce);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c
b/drivers/gpu/drm/i915/gt/intel_context.c
index 745e84c72c90..9e33efb594dd 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -34,6 +34,23 @@ void intel_context_free(struct intel_context *ce)
call_rcu(&ce->rcu, rcu_context_free);
}
+/* for user contexts, callers must set ce->vm correctly */
+struct intel_context *
+intel_context_create_user(struct intel_engine_cs *engine)
+{
+ struct intel_context *ce;
+
+ ce = intel_context_alloc();
+ if (!ce)
+ return ERR_PTR(-ENOMEM);
+
+ intel_context_init(ce, engine);
+
+ trace_intel_context_create(ce);
+ return ce;
+}
+
+/* for kernel-internal users only, sets ce->vm to intel_gt.vm */
struct intel_context *
intel_context_create(struct intel_engine_cs *engine)
{
@@ -44,6 +61,8 @@ intel_context_create(struct intel_engine_cs *engine)
return ERR_PTR(-ENOMEM);
intel_context_init(ce, engine);
+ ce->vm = i915_vm_get(engine->gt->vm);
+
trace_intel_context_create(ce);
return ce;
}
@@ -368,6 +387,7 @@ static int sw_fence_dummy_notify(struct i915_sw_fence *sf,
return NOTIFY_DONE;
}
+/* callers must set ce->vm for user or kernel vm as needed */
void
intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
{
@@ -384,8 +404,6 @@ intel_context_init(struct intel_context *ce, struct
intel_engine_cs *engine)
ewma_runtime_init(&ce->runtime.avg);
- ce->vm = i915_vm_get(engine->gt->vm);
-
/* NB ce->signal_link/lock is used under RCU */
spin_lock_init(&ce->signal_lock);
INIT_LIST_HEAD(&ce->signals);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.h
b/drivers/gpu/drm/i915/gt/intel_context.h
index c41098950746..a80018d53a36 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.h
+++ b/drivers/gpu/drm/i915/gt/intel_context.h
@@ -34,6 +34,8 @@ void intel_context_fini(struct intel_context *ce);
void i915_context_module_exit(void);
int i915_context_module_init(void);
+struct intel_context *
+intel_context_create_user(struct intel_engine_cs *engine);
struct intel_context *
intel_context_create(struct intel_engine_cs *engine);
--
2.32.0
