diff mbox series

[05/21] drm/i915: Drop the CONTEXT_CLONE API

Message ID 20210423223131.879208-6-jason@jlekstrand.net (mailing list archive)
State New, archived
Headers show
Series drm/i915/gem: ioctl clean-ups | expand

Commit Message

Jason Ekstrand April 23, 2021, 10:31 p.m. UTC
This API allows one context to grab bits out of another context upon
creation.  It can be used as a short-cut for setparam(getparam()) for
things like I915_CONTEXT_PARAM_VM.  However, it's never been used by any
real userspace.  It's used by a few IGT tests and that's it.  Since it
doesn't add any real value (most of the stuff you can CLONE you can copy
in other ways), drop it.

There is one thing that this API allows you to clone which you cannot
clone via getparam/setparam: timelines.  However, timelines are an
implementation detail of i915 and not really something that needs to be
exposed to userspace.  Also, sharing timelines between contexts isn't
obviously useful and supporting it has the potential to complicate i915
internally.  It also doesn't add any functionality that the client can't
get in other ways.  If a client really wants a shared timeline, they can
use a syncobj and set it as an in and out fence on every submit.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_context.c | 199 +-------------------
 include/uapi/drm/i915_drm.h                 |  16 +-
 2 files changed, 6 insertions(+), 209 deletions(-)

Comments

Daniel Vetter April 27, 2021, 9:49 a.m. UTC | #1
On Fri, Apr 23, 2021 at 05:31:15PM -0500, Jason Ekstrand wrote:
> This API allows one context to grab bits out of another context upon
> creation.  It can be used as a short-cut for setparam(getparam()) for
> things like I915_CONTEXT_PARAM_VM.  However, it's never been used by any
> real userspace.  It's used by a few IGT tests and that's it.  Since it
> doesn't add any real value (most of the stuff you can CLONE you can copy
> in other ways), drop it.
> 
> There is one thing that this API allows you to clone which you cannot
> clone via getparam/setparam: timelines.  However, timelines are an
> implementation detail of i915 and not really something that needs to be
> exposed to userspace.  Also, sharing timelines between contexts isn't
> obviously useful and supporting it has the potential to complicate i915
> internally.  It also doesn't add any functionality that the client can't
> get in other ways.  If a client really wants a shared timeline, they can
> use a syncobj and set it as an in and out fence on every submit.
> 
> Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_context.c | 199 +-------------------
>  include/uapi/drm/i915_drm.h                 |  16 +-
>  2 files changed, 6 insertions(+), 209 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 8a77855123cec..2c2fefa912805 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -1958,207 +1958,14 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
>  	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
>  }
>  
> -static int clone_engines(struct i915_gem_context *dst,
> -			 struct i915_gem_context *src)
> +static int invalid_ext(struct i915_user_extension __user *ext, void *data)
>  {
> -	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);

You forgot to gc this function here ^^

> -		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);

Not peeked ahead, but I'm really hoping intel_context_set_gem gets removed
eventually too ...

> -	}
> -	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 a0aaa8298f28d..75a71b6756ed8 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -1887,20 +1887,10 @@ 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

I think we need to put these somewhere else now, here it's just plain
lost. I think in the kerneldoc for
drm_i915_gem_context_create_ext_setparam would be best, with the #define
right above and in the kerneldoc an enumeration of all the values and what
they're for.

I think I'll need to sign up Matt B or you for doing some kerneldoc polish
on these so they're all collected together.
-Daniel

> -	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;
> -- 
> 2.31.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Tvrtko Ursulin April 28, 2021, 3:59 p.m. UTC | #2
On 23/04/2021 23:31, Jason Ekstrand wrote:
> This API allows one context to grab bits out of another context upon
> creation.  It can be used as a short-cut for setparam(getparam()) for
> things like I915_CONTEXT_PARAM_VM.  However, it's never been used by any
> real userspace.  It's used by a few IGT tests and that's it.  Since it
> doesn't add any real value (most of the stuff you can CLONE you can copy
> in other ways), drop it.
> 
> There is one thing that this API allows you to clone which you cannot
> clone via getparam/setparam: timelines.  However, timelines are an
> implementation detail of i915 and not really something that needs to be
> exposed to userspace.  Also, sharing timelines between contexts isn't
> obviously useful and supporting it has the potential to complicate i915
> internally.  It also doesn't add any functionality that the client can't
> get in other ways.  If a client really wants a shared timeline, they can
> use a syncobj and set it as an in and out fence on every submit.
> 
> Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

As mentioned before I have no major problem with removing unused uapi 
apart from disagreeing on when to do it. And the fact I find cloning a 
very plausible equivalent of clone(2). Which is an established nice 
model and all. So a sad ack is all I can give.

Regards,

Tvrtko

> ---
>   drivers/gpu/drm/i915/gem/i915_gem_context.c | 199 +-------------------
>   include/uapi/drm/i915_drm.h                 |  16 +-
>   2 files changed, 6 insertions(+), 209 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index 8a77855123cec..2c2fefa912805 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -1958,207 +1958,14 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
>   	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
>   }
>   
> -static int clone_engines(struct i915_gem_context *dst,
> -			 struct i915_gem_context *src)
> +static int invalid_ext(struct i915_user_extension __user *ext, void *data)
>   {
> -	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);
> -	}
> -	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 a0aaa8298f28d..75a71b6756ed8 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -1887,20 +1887,10 @@ 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;
>
Jason Ekstrand April 28, 2021, 5:38 p.m. UTC | #3
On Tue, Apr 27, 2021 at 4:49 AM Daniel Vetter <daniel@ffwll.ch> wrote:
>
> On Fri, Apr 23, 2021 at 05:31:15PM -0500, Jason Ekstrand wrote:
> > This API allows one context to grab bits out of another context upon
> > creation.  It can be used as a short-cut for setparam(getparam()) for
> > things like I915_CONTEXT_PARAM_VM.  However, it's never been used by any
> > real userspace.  It's used by a few IGT tests and that's it.  Since it
> > doesn't add any real value (most of the stuff you can CLONE you can copy
> > in other ways), drop it.
> >
> > There is one thing that this API allows you to clone which you cannot
> > clone via getparam/setparam: timelines.  However, timelines are an
> > implementation detail of i915 and not really something that needs to be
> > exposed to userspace.  Also, sharing timelines between contexts isn't
> > obviously useful and supporting it has the potential to complicate i915
> > internally.  It also doesn't add any functionality that the client can't
> > get in other ways.  If a client really wants a shared timeline, they can
> > use a syncobj and set it as an in and out fence on every submit.
> >
> > Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> > ---
> >  drivers/gpu/drm/i915/gem/i915_gem_context.c | 199 +-------------------
> >  include/uapi/drm/i915_drm.h                 |  16 +-
> >  2 files changed, 6 insertions(+), 209 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > index 8a77855123cec..2c2fefa912805 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> > @@ -1958,207 +1958,14 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
> >       return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
> >  }
> >
> > -static int clone_engines(struct i915_gem_context *dst,
> > -                      struct i915_gem_context *src)
> > +static int invalid_ext(struct i915_user_extension __user *ext, void *data)
> >  {
> > -     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);
>
> You forgot to gc this function here ^^

Done, with pleasure!

> > -             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);
>
> Not peeked ahead, but I'm really hoping intel_context_set_gem gets removed
> eventually too ...

I've not gotten rid of it yet but it's on my list of things to clean
up.  The problem is that there are a pile of parameters we want to set
for user engines which we don't set for internal engines:

 - VM
 - priority
 - hangcheck timeout
 - gem_context back-pointer (I'd love to drop this one!)
 - a bunch more when we start shifting more stuff into intel_context

And there are a bunch of places where we create non-user engines.  The
end result being that we have four ugly options:

 1. Set them after the fact as per intel_context_set_gem
 2. Touch all 79 instances of intel_context_create( for each new
create param we add
 3. Add a new struct intel_context_create_args which contains all the
extra stuff and make NULL mean "use the defaults"
 4. Add a new struct i915_gem_engine which is used for client-visible
engines.  When we switch to an engine-based uAPI, this is probably
what would be exposed to userspace.

I'm happy to hear opinions on which of those is the best option. 2. is
clearly a bad idea.


> > -     }
> > -     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 a0aaa8298f28d..75a71b6756ed8 100644
> > --- a/include/uapi/drm/i915_drm.h
> > +++ b/include/uapi/drm/i915_drm.h
> > @@ -1887,20 +1887,10 @@ 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
>
> I think we need to put these somewhere else now, here it's just plain
> lost. I think in the kerneldoc for
> drm_i915_gem_context_create_ext_setparam would be best, with the #define
> right above and in the kerneldoc an enumeration of all the values and what
> they're for.

I fully agree it's not great.  But I'm not sure create_ext_setparam
makes sense either.  This is it's own extension that's unrelated to
ext_setparam.

--Jason


> I think I'll need to sign up Matt B or you for doing some kerneldoc polish
> on these so they're all collected together.
> -Daniel
>
> > -     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;
> > --
> > 2.31.1
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 8a77855123cec..2c2fefa912805 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -1958,207 +1958,14 @@  static int create_setparam(struct i915_user_extension __user *ext, void *data)
 	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
 }
 
-static int clone_engines(struct i915_gem_context *dst,
-			 struct i915_gem_context *src)
+static int invalid_ext(struct i915_user_extension __user *ext, void *data)
 {
-	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);
-	}
-	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 a0aaa8298f28d..75a71b6756ed8 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1887,20 +1887,10 @@  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;