Quoting Tvrtko Ursulin (2019-09-18 11:26:57)
>
> On 18/09/2019 10:23, Chris Wilson wrote:
> > Preliminary stub to add engines underneath /sys/class/drm/cardN/, so
> > that we can expose properties on each engine to the sysadmin.
>
> Do we also envisage a need for these future things we'll expose to be
> per-context-engine and not just per physical engine?
At the moment, I only have plans for sysadmin controls of physical
engines. I expect users to configure their own contexts from ioctls,
with restrictions imposed by cgroups, which should cover per-context-engines.
> > To start with we have basic analogues of the i915_query ioctl so that we
> > can pretty print engine discovery from the shell, and flesh out the
> > directory structure. Later we will add writeable sysadmin properties such
> > as per-engine timeout controls.
>
> It would be good to show an example of the layout in commit text.
/sys/class/drm/card0
└── engine
├── bcs0
│ ├── class
│ ├── heartbeat_interval_ms
│ ├── instance
│ ├── mmio_base
│ └── name
├── rcs0
│ ├── class
│ ├── heartbeat_interval_ms
│ ├── instance
│ ├── mmio_base
│ └── name
├── vcs0
│ ├── class
│ ├── heartbeat_interval_ms
│ ├── instance
│ ├── mmio_base
│ └── name
└── vecs0
├── class
├── heartbeat_interval_ms
├── instance
├── mmio_base
└── name
>
> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
> > Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
> > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/i915/Makefile | 3 +-
> > drivers/gpu/drm/i915/gt/intel_engine_sysfs.c | 113 +++++++++++++++++++
> > drivers/gpu/drm/i915/gt/intel_engine_sysfs.h | 14 +++
> > drivers/gpu/drm/i915/i915_sysfs.c | 4 +
> > 4 files changed, 133 insertions(+), 1 deletion(-)
> > create mode 100644 drivers/gpu/drm/i915/gt/intel_engine_sysfs.c
> > create mode 100644 drivers/gpu/drm/i915/gt/intel_engine_sysfs.h
> >
> > diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> > index 658b930d34a8..bbea0d4dadd6 100644
> > --- a/drivers/gpu/drm/i915/Makefile
> > +++ b/drivers/gpu/drm/i915/Makefile
> > @@ -76,8 +76,9 @@ gt-y += \
> > gt/intel_breadcrumbs.o \
> > gt/intel_context.o \
> > gt/intel_engine_cs.o \
> > - gt/intel_engine_pool.o \
> > gt/intel_engine_pm.o \
> > + gt/intel_engine_pool.o \
> > + gt/intel_engine_sysfs.o \
> > gt/intel_engine_user.o \
> > gt/intel_gt.o \
> > gt/intel_gt_irq.o \
> > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_sysfs.c b/drivers/gpu/drm/i915/gt/intel_engine_sysfs.c
> > new file mode 100644
> > index 000000000000..51b4b3f2a808
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/gt/intel_engine_sysfs.c
> > @@ -0,0 +1,113 @@
> > +/*
> > + * SPDX-License-Identifier: MIT
> > + *
> > + * Copyright © 2019 Intel Corporation
> > + */
> > +
> > +#include <linux/kobject.h>
> > +#include <linux/sysfs.h>
> > +
> > +#include "i915_drv.h"
> > +#include "intel_engine.h"
> > +#include "intel_engine_sysfs.h"
> > +
> > +struct kobj_engine {
> > + struct kobject base;
> > + struct intel_engine_cs *engine;
> > +};
> > +
> > +static struct intel_engine_cs *kobj_to_engine(struct kobject *kobj)
> > +{
> > + return container_of(kobj, struct kobj_engine, base)->engine;
> > +}
> > +
> > +static ssize_t
> > +name_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "%s\n", kobj_to_engine(kobj)->name);
>
> Name contains our internal instance number which I think we don't want
> to export.
No it doesn't :-p
> On the other hand we could think of dmesg as user visible so could
> consider tweaking engine->name to be built from uabi components.
Already done.
> > +}
> > +
> > +static ssize_t
> > +class_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "%d\n", kobj_to_engine(kobj)->uabi_class);
> > +}
> > +
> > +static ssize_t
> > +inst_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "%d\n", kobj_to_engine(kobj)->uabi_instance);
> > +}
> > +
> > +static ssize_t
> > +mmio_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
> > +{
> > + return sprintf(buf, "0x%x\n", kobj_to_engine(kobj)->mmio_base);
> > +}
>
> Nice try ;) but I suggest you leave adding mmio for a separate patch.
Just look the other way for once.
> > +static struct kobj_attribute name_attr = __ATTR(name, 0444, name_show, NULL);
> > +static struct kobj_attribute class_attr = __ATTR(class, 0444, class_show, NULL);
> > +static struct kobj_attribute inst_attr = __ATTR(instance, 0444, inst_show, NULL);
> > +static struct kobj_attribute mmio_attr = __ATTR(instance, 0444, mmio_show, NULL);
> > +
> > +static void kobj_engine_release(struct kobject *kobj)
> > +{
> > + kfree(kobj);
> > +}
> > +
> > +static struct kobj_type kobj_engine_type = {
> > + .release = kobj_engine_release,
> > + .sysfs_ops = &kobj_sysfs_ops
> > +};
> > +
> > +static struct kobject *
> > +kobj_engine(struct kobject *dir, struct intel_engine_cs *engine)
> > +{
> > + struct kobj_engine *ke;
> > +
> > + ke = kzalloc(sizeof(*ke), GFP_KERNEL);
> > + if (!ke)
> > + return NULL;
>
> Could embed kobj into the engine?
My thinking was if we did that, the natural hierarchy would be
i915->gt->engine, and I wasn't ready to fully commit to that level of
detail.
>
> > +
> > + kobject_init(&ke->base, &kobj_engine_type);
> > + ke->engine = engine;
> > +
> > + if (kobject_add(&ke->base, dir, "%s", engine->name)) {
> > + kobject_put(&ke->base);
> > + return NULL;
> > + }
> > +
> > + return &ke->base;
> > +}
> > +
> > +void intel_engines_add_sysfs(struct drm_i915_private *i915)
> > +{
> > + static const struct attribute *files[] = {
> > + &name_attr.attr,
> > + &class_attr.attr,
> > + &inst_attr.attr,
> > + &mmio_attr.attr,
> > + };
> > +
> > + struct device *kdev = i915->drm.primary->kdev;
> > + struct intel_engine_cs *engine;
> > + struct kobject *dir;
> > +
> > + dir = kobject_create_and_add("engine", &kdev->kobj);
> > + if (!dir)
> > + return;
> > +
> > + for_each_uabi_engine(engine, i915) {
> > + struct kobject *kobj;
> > +
> > + kobj = kobj_engine(dir, engine);
> > + if (!kobj)
> > + continue;
>
> Could be consistent and log an error in this case as well.
We didn't need to log an error for create_files, sysfs does itself as
well. It just has a __must_check even though its author went on a
crusade saying "it's not fatal, stop propagating the error!". Grr.
> > + if (sysfs_create_files(kobj, files)) {
> > + dev_err(kdev, "Failed to add sysfs engine '%s'\n",
> > + engine->name);
> > + break;
>
> Leaks kobj.
kobj is hooked into and owned by the sysfs tree.
(Or I may be leaking it in the kobject_add...)
> > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_sysfs.h b/drivers/gpu/drm/i915/gt/intel_engine_sysfs.h
> > new file mode 100644
> > index 000000000000..ef44a745b70a
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/gt/intel_engine_sysfs.h
> > @@ -0,0 +1,14 @@
> > +/*
> > + * SPDX-License-Identifier: MIT
> > + *
> > + * Copyright © 2019 Intel Corporation
> > + */
> > +
> > +#ifndef INTEL_ENGINE_SYSFS_H
> > +#define INTEL_ENGINE_SYSFS_H
> > +
> > +struct drm_i915_private;
> > +
> > +void intel_engines_add_sysfs(struct drm_i915_private *i915);
> > +
> > +#endif /* INTEL_ENGINE_SYSFS_H */
> > diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
> > index d8a3b180c084..6b88d934927a 100644
> > --- a/drivers/gpu/drm/i915/i915_sysfs.c
> > +++ b/drivers/gpu/drm/i915/i915_sysfs.c
> > @@ -30,6 +30,8 @@
> > #include <linux/stat.h>
> > #include <linux/sysfs.h>
> >
> > +#include "gt/intel_engine_sysfs.h"
> > +
> > #include "i915_drv.h"
> > #include "i915_sysfs.h"
> > #include "intel_pm.h"
> > @@ -618,6 +620,8 @@ void i915_setup_sysfs(struct drm_i915_private *dev_priv)
> > DRM_ERROR("RPS sysfs setup failed\n");
> >
> > i915_setup_error_capture(kdev);
> > +
> > + intel_engines_add_sysfs(dev_priv);
>
> Or gt?
We want the flat uabi engine list which is tucked away under i915.
-Chris
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
