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

Tvrtko Ursulin
2019-04-08T16:54:47Z

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@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)
> +{

Our coding style is

type *
func_name(..)

(Take care of all instances in source and header.)

> + 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++;
> + 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;

Puzzling choice of errno, not that it matters, but I am tempted to
suggest -ENODEV.

> +
> + 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);

Would it make sense to "poison" flags with like -1 (when listing
subtests) so any mistakes would never have a chance to work?

> +
> + 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);
> +

Extra blank line.

> + } 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])

Do you need these two in the header file?

> +
> +#define GEM_MAX_ENGINES I915_EXEC_RING_MASK + 1
> +
> +struct intel_engine_data {
> + uint32_t nengines;
> + uint32_t n;
> + int error;

Unused?

> + 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',
>

Coding style and question against the header file are the only real ones
left. Otherwise looks good.

Regards,

Tvrtko