[igt-dev] [PATCH v19 2/6] lib/i915: add gem_engine_topology library and for_each loop definition

Tvrtko Ursulin tvrtko.ursulin at linux.intel.com
Thu Apr 11 16:03:58 UTC 2019


On 08/04/2019 17:15, Andi Shyti wrote:
> The gem_engine_topology library is a set of functions that
> interface with the query and getparam/setparam ioctls.
> 
> The library's access point is the 'intel_init_engine_list()'
> function that, everytime is called, generates the list of active
> engines and returns them in a 'struct intel_engine_data'. The
> structure contains only the engines that are actively present in
> the GPU.
> 
> The function can work in both the cases that the query and
> getparam ioctls are implemented or not by the running kernel. In
> case they are implemented, a query is made to the driver to fetch
> the list of active engines. In case they are not implemented, the
> list is taken from the 'intel_execution_engines2' array and
> stored only after checking their presence.
> 
> The gem_engine_topology library provides some iteration helpers:
> 
>   - intel_get_current_engine(): provides the current engine in the
>     iteration.
> 
>   - intel_get_current_physical_engine(): provides the current
>     physical engine, if the current engine is a virtual engine,
>     it moves forward until it finds a physical engine.
> 
>   - intel_next_engine() it just increments the counter so that it
>     points to the next engine.
> 
> Extend the 'for_each_engine_class_instance' so that it can loop
> using the new 'intel_init_engine_list()' and rename it to
> 'for_each_context_engine'.
> 
> Move '__for_each_engine_class_instance' to gem_engine_topology.h
> and rename it to '__for_each_static_engine'.
> 
> Update accordingly tests/perf_pmu.c to use correctly the new
> for_each loops.
> 
> Signed-off-by: Andi Shyti <andi.shyti at intel.com>
> ---
>   lib/Makefile.sources           |   2 +
>   lib/i915/gem_engine_topology.c | 281 +++++++++++++++++++++++++++++++++
>   lib/i915/gem_engine_topology.h |  78 +++++++++
>   lib/igt.h                      |   1 +
>   lib/igt_gt.h                   |   2 +
>   lib/meson.build                |   1 +
>   6 files changed, 365 insertions(+)
>   create mode 100644 lib/i915/gem_engine_topology.c
>   create mode 100644 lib/i915/gem_engine_topology.h
> 
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index e00347f945c5..41331c2f2b80 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -13,6 +13,8 @@ lib_source_list =	 	\
>   	i915/gem_ring.c	\
>   	i915/gem_mman.c	\
>   	i915/gem_mman.h	\
> +	i915/gem_engine_topology.c	\
> +	i915/gem_engine_topology.h	\
>   	i915_3d.h		\
>   	i915_reg.h		\
>   	i915_pciids.h		\
> diff --git a/lib/i915/gem_engine_topology.c b/lib/i915/gem_engine_topology.c
> new file mode 100644
> index 000000000000..06f538372a4d
> --- /dev/null
> +++ b/lib/i915/gem_engine_topology.c
> @@ -0,0 +1,281 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include "drmtest.h"
> +#include "ioctl_wrappers.h"
> +
> +#include "i915/gem_engine_topology.h"
> +
> +static int __gem_query(int fd, struct drm_i915_query *q)
> +{
> +	int err = 0;
> +
> +	if (igt_ioctl(fd, DRM_IOCTL_I915_QUERY, q))
> +		err = -errno;
> +
> +	errno = 0;
> +	return err;
> +}
> +
> +static void gem_query(int fd, struct drm_i915_query *q)
> +{
> +	igt_assert_eq(__gem_query(fd, q), 0);
> +}
> +
> +static void query_engines(int fd,
> +			  struct drm_i915_query_engine_info *query_engines,
> +			  int length)
> +{
> +	struct drm_i915_query_item item = { };
> +	struct drm_i915_query query = { };
> +
> +	item.query_id = DRM_I915_QUERY_ENGINE_INFO;
> +	query.items_ptr = to_user_pointer(&item);
> +	query.num_items = 1;
> +	item.length = length;
> +
> +	item.data_ptr = to_user_pointer(query_engines);
> +
> +	gem_query(fd, &query);
> +}
> +
> +static void ctx_map_engines(int fd, struct intel_engine_data *ed,
> +			    struct drm_i915_gem_context_param *param)
> +{
> +	struct i915_context_param_engines *engines =
> +			(struct i915_context_param_engines *) param->value;
> +	int i = 0;
> +
> +	for (typeof(engines->class_instance[0]) *p =
> +	     &engines->class_instance[0];
> +	     i < ed->nengines; i++, p++) {
> +		p->engine_class = ed->engines[i].class;
> +		p->engine_instance = ed->engines[i].instance;
> +	}
> +
> +	param->size = offsetof(typeof(*engines), class_instance[i]);
> +	engines->extensions = 0;
> +
> +	gem_context_set_param(fd, param);
> +}
> +
> +static void init_engine(struct intel_execution_engine2 *e2,
> +			int class, int instance, uint64_t flags)
> +{
> +	const struct intel_execution_engine2 *__e2;
> +	static const char *unknown_name = "unknown",
> +			  *virtual_name = "virtual";
> +
> +	e2->class    = class;
> +	e2->instance = instance;
> +	e2->flags    = flags;
> +
> +	/* engine is a virtual engine */
> +	if (class == I915_ENGINE_CLASS_INVALID) {
> +		e2->name = virtual_name;
> +		e2->is_virtual = true;
> +		return;
> +	}
> +
> +	__for_each_static_engine(__e2)
> +		if (__e2->class == class && __e2->instance == instance)
> +			break;
> +
> +	if (__e2->name) {
> +		e2->name = __e2->name;
> +	} else {
> +		igt_warn("found unknown engine (%d, %d)", class, instance);
> +		e2->name = unknown_name;
> +	}
> +
> +	/* just to remark it */
> +	e2->is_virtual = false;
> +}
> +
> +static void query_engine_list(int fd, struct intel_engine_data *ed)
> +{
> +	uint8_t buff[SIZEOF_QUERY] = { };
> +	struct drm_i915_query_engine_info *query_engine =
> +			(struct drm_i915_query_engine_info *) buff;
> +	int i;
> +
> +	query_engines(fd, query_engine, SIZEOF_QUERY);
> +
> +	for (i = 0; i < query_engine->num_engines; i++)
> +		init_engine(&ed->engines[i],
> +			    query_engine->engines[i].engine_class,
> +			    query_engine->engines[i].engine_instance, i);
> +
> +	ed->nengines = query_engine->num_engines;
> +}
> +
> +struct intel_execution_engine2
> +*intel_get_current_engine(struct intel_engine_data *ed)
> +{
> +	if (!ed->n)
> +		ed->current_engine = &ed->engines[0];
> +	else if (ed->n >= ed->nengines)
> +		ed->current_engine = NULL;
> +
> +	return ed->current_engine;
> +}
> +
> +void intel_next_engine(struct intel_engine_data *ed)
> +{
> +	if (ed->n + 1 < ed->nengines) {
> +		ed->n++;

This is broken for one engine. It should read:

	if (++ed->n < ed->nengines)
		ed->current_engine = &ed->engines[ed->n];
	else
		ed->current_engine = NULL;

Otherwise ed->n is always zero and it never progresses.

*However*... there is a mystery to solve in why with the broken code if 
you run gem_wait --r basic-busy-all the loop still exits (on my system 
after 65 iterations).

On the other hand my system "perf_pmu --list" loops forever as expected.

I fear there is some stack corruption or something. But Valgrind does 
not catch anything.

You can comment out all but RCS in the static engine list and test. And 
OFC use drm-tip so legacy path runs.

Regards,

Tvrtko


> +		ed->current_engine = &ed->engines[ed->n];
> +	} else {
> +		ed->current_engine = NULL;
> +	}
> +}
> +
> +struct intel_execution_engine2
> +*intel_get_current_physical_engine(struct intel_engine_data *ed)
> +{
> +	struct intel_execution_engine2 *e;
> +
> +	for (e = intel_get_current_engine(ed);
> +	     e && e->is_virtual;
> +	     intel_next_engine(ed))
> +		;
> +
> +	return e;
> +}
> +
> +static int gem_topology_get_param(int fd, uint32_t ctx,
> +				  struct drm_i915_gem_context_param *p)
> +{
> +	int nengines;
> +	int ret;
> +
> +	if (igt_only_list_subtests())
> +		return -EPERM;
> +
> +	ret = __gem_context_get_param(fd, p);
> +	if (ret)
> +		return ret;
> +
> +	nengines = p->size > sizeof(struct i915_context_param_engines) ?
> +		   (p->size - sizeof(struct i915_context_param_engines)) /
> +		   (2 * sizeof(__u16)) :
> +		   0;
> +
> +	igt_assert_f(nengines <= GEM_MAX_ENGINES, "unsupported engine count\n");
> +
> +	return nengines;
> +}
> +
> +struct intel_engine_data intel_init_engine_list(int fd, uint32_t ctx_id)
> +{
> +	I915_DEFINE_CONTEXT_PARAM_ENGINES(engines, GEM_MAX_ENGINES);
> +	struct intel_engine_data engine_data = { };
> +	struct drm_i915_gem_context_param param = {
> +		.param = I915_CONTEXT_PARAM_ENGINES,
> +		.ctx_id = ctx_id,
> +		.size = SIZEOF_CTX_PARAM,
> +		.value = to_user_pointer(&engines),
> +	};
> +	int nengines = gem_topology_get_param(fd, ctx_id, &param);
> +	int i;
> +
> +	if (nengines < 0) {
> +		/* if kernel does not support engine/context mapping */
> +		const struct intel_execution_engine2 *e2;
> +
> +		igt_debug("using pre-allocated engine list\n");
> +
> +		__for_each_static_engine(e2) {
> +			struct intel_execution_engine2 *__e2 =
> +				&engine_data.engines[engine_data.nengines];
> +
> +			if (!igt_only_list_subtests()) {
> +				__e2->flags = gem_class_instance_to_eb_flags(fd,
> +						e2->class, e2->instance);
> +
> +				if (!gem_has_ring(fd, __e2->flags))
> +					continue;
> +			}
> +
> +			__e2->name       = e2->name;
> +			__e2->instance   = e2->instance;
> +			__e2->class      = e2->class;
> +			__e2->is_virtual = false;
> +
> +			engine_data.nengines++;
> +		}
> +		return engine_data;
> +	}
> +
> +	if (!param.size) {
> +		/* else if context doesn't have mapped engines */
> +		query_engine_list(fd, &engine_data);
> +		ctx_map_engines(fd, &engine_data, &param);
> +
> +	} else {
> +		/* context has a list of mapped engines */
> +
> +		for (i = 0; i < nengines; i++)
> +			init_engine(&engine_data.engines[i],
> +				    engines.class_instance[i].engine_class,
> +				    engines.class_instance[i].engine_instance,
> +				    i);
> +
> +		engine_data.nengines = i;
> +	}
> +
> +	return engine_data;
> +}
> +
> +int gem_ctx_get_engine(int fd, uint32_t engine, uint32_t ctx_id,
> +		       struct intel_execution_engine2 *e)
> +{
> +	I915_DEFINE_CONTEXT_PARAM_ENGINES(engines, GEM_MAX_ENGINES);
> +	struct drm_i915_gem_context_param param = {
> +		.param = I915_CONTEXT_PARAM_ENGINES,
> +		.ctx_id = ctx_id,
> +		.size = SIZEOF_CTX_PARAM,
> +		.value = to_user_pointer(&engines),
> +	};
> +	int nengines = gem_topology_get_param(fd, ctx_id, &param);
> +
> +	if (nengines < 0)
> +		return nengines;
> +
> +	if (!param.size || !nengines)
> +		return -EINVAL;
> +
> +	e->class = engines.class_instance[engine].engine_class;
> +	e->instance = engines.class_instance[engine].engine_instance;
> +
> +	return 0;
> +}
> +
> +bool gem_has_engine_topology(int fd)
> +{
> +	struct drm_i915_gem_context_param param = {
> +		.param = I915_CONTEXT_PARAM_ENGINES,
> +	};
> +
> +	return !__gem_context_get_param(fd, &param);
> +}
> diff --git a/lib/i915/gem_engine_topology.h b/lib/i915/gem_engine_topology.h
> new file mode 100644
> index 000000000000..806c260b1074
> --- /dev/null
> +++ b/lib/i915/gem_engine_topology.h
> @@ -0,0 +1,78 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#ifndef GEM_ENGINE_TOPOLOGY_H
> +#define GEM_ENGINE_TOPOLOGY_H
> +
> +#include "igt_gt.h"
> +#include "i915_drm.h"
> +
> +/*
> + * Limit what we support for simplicity due limitation in how much we
> + * can address via execbuf2.
> + */
> +#define SIZEOF_CTX_PARAM	offsetof(struct i915_context_param_engines, \
> +					class_instance[GEM_MAX_ENGINES])
> +#define SIZEOF_QUERY		offsetof(struct drm_i915_query_engine_info, \
> +					engines[GEM_MAX_ENGINES])
> +
> +#define GEM_MAX_ENGINES		I915_EXEC_RING_MASK + 1
> +
> +struct intel_engine_data {
> +	uint32_t nengines;
> +	uint32_t n;
> +	int error;
> +	struct intel_execution_engine2 *current_engine;
> +	struct intel_execution_engine2 engines[GEM_MAX_ENGINES];
> +};
> +
> +bool gem_has_engine_topology(int fd);
> +struct intel_engine_data intel_init_engine_list(int fd, uint32_t ctx_id);
> +
> +/* iteration functions */
> +struct intel_execution_engine2
> +*intel_get_current_engine(struct intel_engine_data *ed);
> +
> +struct intel_execution_engine2
> +*intel_get_current_physical_engine(struct intel_engine_data *ed);
> +
> +void intel_next_engine(struct intel_engine_data *ed);
> +
> +int gem_ctx_get_engine(int fd, uint32_t engine, uint32_t ctx_id,
> +		       struct intel_execution_engine2 *e);
> +
> +#define __for_each_static_engine(e__) \
> +	for ((e__) = intel_execution_engines2; (e__)->name; (e__)++)
> +
> +#define for_each_context_engine(fd__, ctx__, e__) \
> +	for (struct intel_engine_data i__ = intel_init_engine_list(fd__, ctx__); \
> +	     ((e__) = intel_get_current_engine(&i__)); \
> +	     intel_next_engine(&i__))
> +
> +/* needs to replace "for_each_physical_engine" when conflicts are fixed */
> +#define __for_each_physical_engine(fd__, e__) \
> +	for (struct intel_engine_data i__ = intel_init_engine_list(fd__, 0); \
> +	     ((e__) = intel_get_current_physical_engine(&i__)); \
> +	     intel_next_engine(&i__))
> +
> +#endif /* GEM_ENGINE_TOPOLOGY_H */
> diff --git a/lib/igt.h b/lib/igt.h
> index 6654a659c062..03f19ca2dfb6 100644
> --- a/lib/igt.h
> +++ b/lib/igt.h
> @@ -53,5 +53,6 @@
>   #include "media_spin.h"
>   #include "rendercopy.h"
>   #include "i915/gem_mman.h"
> +#include "i915/gem_engine_topology.h"
>   
>   #endif /* IGT_H */
> diff --git a/lib/igt_gt.h b/lib/igt_gt.h
> index 475c0b3c3cc6..52b2f1ea95a5 100644
> --- a/lib/igt_gt.h
> +++ b/lib/igt_gt.h
> @@ -95,6 +95,8 @@ extern const struct intel_execution_engine2 {
>   	const char *name;
>   	int class;
>   	int instance;
> +	uint64_t flags;
> +	bool is_virtual;
>   } intel_execution_engines2[];
>   
>   unsigned int
> diff --git a/lib/meson.build b/lib/meson.build
> index 89de06e6924a..93c01daa4222 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -5,6 +5,7 @@ lib_sources = [
>   	'i915/gem_submission.c',
>   	'i915/gem_ring.c',
>   	'i915/gem_mman.c',
> +	'i915/gem_engine_topology.c',
>   	'igt_color_encoding.c',
>   	'igt_debugfs.c',
>   	'igt_device.c',
> 


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