Commit 4ec76dbe authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gt: Expose engine properties via sysfs 



Preliminary stub to add engines underneath /sys/class/drm/cardN/, so
that we can expose properties on each engine to the sysadmin.

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.

An example tree of the engine properties on Braswell:
    /sys/class/drm/card0
    └── engine
        ├── bcs0
        │   ├── capabilities
        │   ├── class
        │   ├── instance
        │   ├── known_capabilities
        │   └── name
        ├── rcs0
        │   ├── capabilities
        │   ├── class
        │   ├── instance
        │   ├── known_capabilities
        │   └── name
        ├── vcs0
        │   ├── capabilities
        │   ├── class
        │   ├── instance
        │   ├── known_capabilities
        │   └── name
        └── vecs0
            ├── capabilities
            ├── class
            ├── instance
            ├── known_capabilities
            └── name

v2: Include stringified capabilities
v3: Include all known capabilities for futureproofing.
v4: Combine the two caps loops into one

v5: Hide underneath Kconfig.unstable for wider discussion

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Tested-by: default avatarSteve Carbonari <steven.carbonari@intel.com>
Reviewed-by: default avatarSteve Carbonari <steven.carbonari@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200228131716.3243616-1-chris@chris-wilson.co.uk
parent efbf9288

drivers/gpu/drm/i915/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -109,7 +109,8 @@ gt-y += \ 
	gt/intel_rps.o \

	gt/intel_sseu.o \

	gt/intel_timeline.o \

	gt/intel_workarounds.o

	gt/intel_workarounds.o \

	gt/sysfs_engines.o

# autogenerated null render state

gt-y += \

	gt/gen6_renderstate.o \

drivers/gpu/drm/i915/gt/sysfs_engines.c

0 → 100644
+205 −0
Original line number Diff line number Diff line 
// 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 "sysfs_engines.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);

}



static struct kobj_attribute name_attr =

__ATTR(name, 0444, name_show, NULL);



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 struct kobj_attribute class_attr =

__ATTR(class, 0444, class_show, NULL);



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 struct kobj_attribute inst_attr =

__ATTR(instance, 0444, inst_show, NULL);



static const char * const vcs_caps[] = {

	[ilog2(I915_VIDEO_CLASS_CAPABILITY_HEVC)] = "hevc",

	[ilog2(I915_VIDEO_AND_ENHANCE_CLASS_CAPABILITY_SFC)] = "sfc",

};



static const char * const vecs_caps[] = {

	[ilog2(I915_VIDEO_AND_ENHANCE_CLASS_CAPABILITY_SFC)] = "sfc",

};



static ssize_t repr_trim(char *buf, ssize_t len)

{

	/* Trim off the trailing space and replace with a newline */

	if (len > PAGE_SIZE)

		len = PAGE_SIZE;

	if (len > 0)

		buf[len - 1] = '\n';



	return len;

}



static ssize_t

__caps_show(struct intel_engine_cs *engine,

	    u32 caps, char *buf, bool show_unknown)

{

	const char * const *repr;

	int count, n;

	ssize_t len;



	BUILD_BUG_ON(!typecheck(typeof(caps), engine->uabi_capabilities));



	switch (engine->class) {

	case VIDEO_DECODE_CLASS:

		repr = vcs_caps;

		count = ARRAY_SIZE(vcs_caps);

		break;



	case VIDEO_ENHANCEMENT_CLASS:

		repr = vecs_caps;

		count = ARRAY_SIZE(vecs_caps);

		break;



	default:

		repr = NULL;

		count = 0;

		break;

	}

	GEM_BUG_ON(count > BITS_PER_TYPE(typeof(caps)));



	len = 0;

	for_each_set_bit(n,

			 (unsigned long *)&caps,

			 show_unknown ? BITS_PER_TYPE(typeof(caps)) : count) {

		if (n >= count || !repr[n]) {

			if (GEM_WARN_ON(show_unknown))

				len += snprintf(buf + len, PAGE_SIZE - len,

						"[%x] ", n);

		} else {

			len += snprintf(buf + len, PAGE_SIZE - len,

					"%s ", repr[n]);

		}

		if (GEM_WARN_ON(len >= PAGE_SIZE))

			break;

	}

	return repr_trim(buf, len);

}



static ssize_t

caps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)

{

	struct intel_engine_cs *engine = kobj_to_engine(kobj);



	return __caps_show(engine, engine->uabi_capabilities, buf, true);

}



static struct kobj_attribute caps_attr =

__ATTR(capabilities, 0444, caps_show, NULL);



static ssize_t

all_caps_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)

{

	return __caps_show(kobj_to_engine(kobj), -1, buf, false);

}



static struct kobj_attribute all_caps_attr =

__ATTR(known_capabilities, 0444, all_caps_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;



	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;

	}



	/* xfer ownership to sysfs tree */

	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,

		&caps_attr.attr,

		&all_caps_attr.attr,

		NULL

	};



	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)

			goto err_engine;



		if (sysfs_create_files(kobj, files))

			goto err_object;



		if (0) {

err_object:

			kobject_put(kobj);

err_engine:

			dev_err(kdev, "Failed to add sysfs engine '%s'\n",

				engine->name);

			break;

		}

	}

}

drivers/gpu/drm/i915/gt/sysfs_engines.h

0 → 100644
+13 −0
Original line number Diff line number Diff line 
/* 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 */

drivers/gpu/drm/i915/i915_sysfs.c

+3 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 


#include "gt/intel_rc6.h"

#include "gt/intel_rps.h"

#include "gt/sysfs_engines.h"



#include "i915_drv.h"

#include "i915_sysfs.h"
@@ -606,6 +607,8 @@ void i915_setup_sysfs(struct drm_i915_private *dev_priv) 
		drm_err(&dev_priv->drm, "RPS sysfs setup failed\n");



	i915_setup_error_capture(kdev);



	intel_engines_add_sysfs(dev_priv);

}



void i915_teardown_sysfs(struct drm_i915_private *dev_priv)

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