[PATCH 4/5] drm/i915: Drop the CONTEXT_CLONE API

Jason Ekstrand jason at jlekstrand.net
Wed Mar 17 23:40:13 UTC 2021


It's never been used by any real userspace.  It's used by IGT as a
short-cut for sharing VMs and other stuff between contexts.

Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 217 +-------------------
 include/uapi/drm/i915_drm.h                 |  16 +-
 2 files changed, 6 insertions(+), 227 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index ca37d93ef5e78..92256f4e50764 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -2103,225 +2103,14 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
 	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
 }
 
-static int copy_ring_size(struct intel_context *dst,
-			  struct intel_context *src)
+static int invalid_ext(struct i915_user_extension __user *ext, void *data)
 {
-	long sz;
-
-	sz = intel_context_get_ring_size(src);
-	if (sz < 0)
-		return sz;
-
-	return intel_context_set_ring_size(dst, sz);
-}
-
-static int clone_engines(struct i915_gem_context *dst,
-			 struct i915_gem_context *src)
-{
-	struct i915_gem_engines *clone, *e;
-	bool user_engines;
-	unsigned long n;
-
-	e = __context_engines_await(src, &user_engines);
-	if (!e)
-		return -ENOENT;
-
-	clone = alloc_engines(e->num_engines);
-	if (!clone)
-		goto err_unlock;
-
-	for (n = 0; n < e->num_engines; n++) {
-		struct intel_engine_cs *engine;
-
-		if (!e->engines[n]) {
-			clone->engines[n] = NULL;
-			continue;
-		}
-		engine = e->engines[n]->engine;
-
-		/*
-		 * Virtual engines are singletons; they can only exist
-		 * inside a single context, because they embed their
-		 * HW context... As each virtual context implies a single
-		 * timeline (each engine can only dequeue a single request
-		 * at any time), it would be surprising for two contexts
-		 * to use the same engine. So let's create a copy of
-		 * the virtual engine instead.
-		 */
-		if (intel_engine_is_virtual(engine))
-			clone->engines[n] =
-				intel_execlists_clone_virtual(engine);
-		else
-			clone->engines[n] = intel_context_create(engine);
-		if (IS_ERR_OR_NULL(clone->engines[n])) {
-			__free_engines(clone, n);
-			goto err_unlock;
-		}
-
-		intel_context_set_gem(clone->engines[n], dst);
-
-		/* Copy across the preferred ringsize */
-		if (copy_ring_size(clone->engines[n], e->engines[n])) {
-			__free_engines(clone, n + 1);
-			goto err_unlock;
-		}
-	}
-	clone->num_engines = n;
-	i915_sw_fence_complete(&e->fence);
-
-	/* Serialised by constructor */
-	engines_idle_release(dst, rcu_replace_pointer(dst->engines, clone, 1));
-	if (user_engines)
-		i915_gem_context_set_user_engines(dst);
-	else
-		i915_gem_context_clear_user_engines(dst);
-	return 0;
-
-err_unlock:
-	i915_sw_fence_complete(&e->fence);
-	return -ENOMEM;
-}
-
-static int clone_flags(struct i915_gem_context *dst,
-		       struct i915_gem_context *src)
-{
-	dst->user_flags = src->user_flags;
-	return 0;
-}
-
-static int clone_schedattr(struct i915_gem_context *dst,
-			   struct i915_gem_context *src)
-{
-	dst->sched = src->sched;
-	return 0;
-}
-
-static int clone_sseu(struct i915_gem_context *dst,
-		      struct i915_gem_context *src)
-{
-	struct i915_gem_engines *e = i915_gem_context_lock_engines(src);
-	struct i915_gem_engines *clone;
-	unsigned long n;
-	int err;
-
-	/* no locking required; sole access under constructor*/
-	clone = __context_engines_static(dst);
-	if (e->num_engines != clone->num_engines) {
-		err = -EINVAL;
-		goto unlock;
-	}
-
-	for (n = 0; n < e->num_engines; n++) {
-		struct intel_context *ce = e->engines[n];
-
-		if (clone->engines[n]->engine->class != ce->engine->class) {
-			/* Must have compatible engine maps! */
-			err = -EINVAL;
-			goto unlock;
-		}
-
-		/* serialises with set_sseu */
-		err = intel_context_lock_pinned(ce);
-		if (err)
-			goto unlock;
-
-		clone->engines[n]->sseu = ce->sseu;
-		intel_context_unlock_pinned(ce);
-	}
-
-	err = 0;
-unlock:
-	i915_gem_context_unlock_engines(src);
-	return err;
-}
-
-static int clone_timeline(struct i915_gem_context *dst,
-			  struct i915_gem_context *src)
-{
-	if (src->timeline)
-		__assign_timeline(dst, src->timeline);
-
-	return 0;
-}
-
-static int clone_vm(struct i915_gem_context *dst,
-		    struct i915_gem_context *src)
-{
-	struct i915_address_space *vm;
-	int err = 0;
-
-	if (!rcu_access_pointer(src->vm))
-		return 0;
-
-	rcu_read_lock();
-	vm = context_get_vm_rcu(src);
-	rcu_read_unlock();
-
-	if (!mutex_lock_interruptible(&dst->mutex)) {
-		__assign_ppgtt(dst, vm);
-		mutex_unlock(&dst->mutex);
-	} else {
-		err = -EINTR;
-	}
-
-	i915_vm_put(vm);
-	return err;
-}
-
-static int create_clone(struct i915_user_extension __user *ext, void *data)
-{
-	static int (* const fn[])(struct i915_gem_context *dst,
-				  struct i915_gem_context *src) = {
-#define MAP(x, y) [ilog2(I915_CONTEXT_CLONE_##x)] = y
-		MAP(ENGINES, clone_engines),
-		MAP(FLAGS, clone_flags),
-		MAP(SCHEDATTR, clone_schedattr),
-		MAP(SSEU, clone_sseu),
-		MAP(TIMELINE, clone_timeline),
-		MAP(VM, clone_vm),
-#undef MAP
-	};
-	struct drm_i915_gem_context_create_ext_clone local;
-	const struct create_ext *arg = data;
-	struct i915_gem_context *dst = arg->ctx;
-	struct i915_gem_context *src;
-	int err, bit;
-
-	if (copy_from_user(&local, ext, sizeof(local)))
-		return -EFAULT;
-
-	BUILD_BUG_ON(GENMASK(BITS_PER_TYPE(local.flags) - 1, ARRAY_SIZE(fn)) !=
-		     I915_CONTEXT_CLONE_UNKNOWN);
-
-	if (local.flags & I915_CONTEXT_CLONE_UNKNOWN)
-		return -EINVAL;
-
-	if (local.rsvd)
-		return -EINVAL;
-
-	rcu_read_lock();
-	src = __i915_gem_context_lookup_rcu(arg->fpriv, local.clone_id);
-	rcu_read_unlock();
-	if (!src)
-		return -ENOENT;
-
-	GEM_BUG_ON(src == dst);
-
-	for (bit = 0; bit < ARRAY_SIZE(fn); bit++) {
-		if (!(local.flags & BIT(bit)))
-			continue;
-
-		err = fn[bit](dst, src);
-		if (err)
-			return err;
-	}
-
-	return 0;
+	return -EINVAL;
 }
 
 static const i915_user_extension_fn create_extensions[] = {
 	[I915_CONTEXT_CREATE_EXT_SETPARAM] = create_setparam,
-	[I915_CONTEXT_CREATE_EXT_CLONE] = create_clone,
+	[I915_CONTEXT_CREATE_EXT_CLONE] = invalid_ext,
 };
 
 static bool client_is_banned(struct drm_i915_file_private *file_priv)
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index ddc47bbf48b6d..0ed1b88afedd5 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1853,20 +1853,10 @@ struct drm_i915_gem_context_create_ext_setparam {
 	struct drm_i915_gem_context_param param;
 };
 
-struct drm_i915_gem_context_create_ext_clone {
+/* This API has been removed.  On the off chance someone somewhere has
+ * attempted to use it, never re-use this extension number.
+ */
 #define I915_CONTEXT_CREATE_EXT_CLONE 1
-	struct i915_user_extension base;
-	__u32 clone_id;
-	__u32 flags;
-#define I915_CONTEXT_CLONE_ENGINES	(1u << 0)
-#define I915_CONTEXT_CLONE_FLAGS	(1u << 1)
-#define I915_CONTEXT_CLONE_SCHEDATTR	(1u << 2)
-#define I915_CONTEXT_CLONE_SSEU		(1u << 3)
-#define I915_CONTEXT_CLONE_TIMELINE	(1u << 4)
-#define I915_CONTEXT_CLONE_VM		(1u << 5)
-#define I915_CONTEXT_CLONE_UNKNOWN -(I915_CONTEXT_CLONE_VM << 1)
-	__u64 rsvd;
-};
 
 struct drm_i915_gem_context_destroy {
 	__u32 ctx_id;
-- 
2.29.2



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