Re: [igt-dev] [PATCH v11 2/6] lib/i915: add gem_engine_topology library

Tvrtko Ursulin
2019-03-13T07:42:01Z

On 12/03/2019 17:17, 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 three main access points are:
>
> - get_active_engines()
> - __gem_prepare_context_engines()
> - igt_require_gem_engine_list()
>
> The first two functions are similar, with the difference that the
> 'gem_set_context_get_engines()' sets the engine before returning
> the engine list in a 'intel_execution_engine2' type array.
> Another improtant difference is that the first function works
> only with the getparam/setparam and query ioctls are implemented
> and it return 'NULL' in the other case.
> It can be also used to check whether the current kernel contains
> the new API.
>
> '__gem_prepare_context_engines()' function, at the first call
> generates the array of active engines (either physical or
> virtual) called 'intel_active_engines2'.
> If the driver cannot be queried, the 'intel_active_engines2'
> array points to the exisiting 'intel_execution_engines2' which
> has been previously defined.
>
> The value of the 'intel_active_engines2' will be used in further
> calls to check whether the above mentioned ioctls are implemented
> without the need to call getparam().
>
> The 'igt_require_gem_engine_list()' causes the test to fail in
> case the required ioctls are not implemented.
>
> Signed-off-by: Andi Shyti <andi.shyti@intel.com>
> ---
> Hi Tvrtko,
>
> the only thing I left untouched here is the fixed SIZEOF_QUERY,
> even though the query ioctl doesn't have any limitation on query
> size. The reason is because we've been discussing with Chris
> setting a fixed size to prioritise stack allocation over heap
> allocation so that I changed it to the way is done now from the
> way you recommended at the beginning (already).
>
> Andi
>
> lib/Makefile.sources | 2 +
> lib/i915/gem_engine_topology.c | 193 +++++++++++++++++++++++++++++++++
> lib/i915/gem_engine_topology.h | 33 ++++++
> lib/igt_gt.c | 2 +-
> lib/igt_gt.h | 2 +-
> lib/meson.build | 1 +
> 6 files changed, 231 insertions(+), 2 deletions(-)
> 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 cf2720981707..757bd7a17ebe 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..6d6cb85b0a26
> --- /dev/null
> +++ b/lib/i915/gem_engine_topology.c
> @@ -0,0 +1,193 @@
> +/*
> + * 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 "igt_gt.h"
> +#include "ioctl_wrappers.h"
> +
> +#include "i915/gem_engine_topology.h"
> +
> +#define SIZEOF_CTX_PARAM offsetof(struct i915_context_param_engines, \
> + class_instance[I915_EXEC_RING_MASK + 1])
> +#define SIZEOF_QUERY offsetof(struct drm_i915_query_engine_info, \
> + engines[I915_EXEC_RING_MASK + 1])
> +
> +static struct intel_execution_engine2 *intel_active_engines2;
> +static bool ctx_is_set;
> +
> +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)
> +{
> + 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 = SIZEOF_QUERY;
> +
> + item.data_ptr = to_user_pointer(query_engines);
> +
> + gem_query(fd, &query);
> +}
> +
> +static void set_ctx_param_engines(int fd, uint32_t ctx_id)
> +{
> + struct i915_context_param_engines *ctx_engine;
> + struct drm_i915_gem_context_param ctx_param;
> + const struct intel_execution_engine2 *e2;
> + uint8_t buff[SIZEOF_CTX_PARAM] = { };
> + int i;
> +
> + if (ctx_is_set)
> + return;

A global ctx_is_set bool doesn't work with passed in ctx_id I think!?

But more importantly.. could you try and make the iterator work of the
local ctx.get_engines() query? Only configuring the ctx map to include
all engines if not already set.

Chris had a suggestion in the previous posting to use an iterator struct
which I think has merit since it hides the explicit index var/param.
(155179296327.27405.14019468668411244512@skylake-alporthouse-com)

And then I'd drop the for_each_engine2 and just convert
for_each_engine_class_instance straight away. Only one test uses it so
shouldn't be too hard (perf_pmu).

This will I think require adding the gem_set_eb_engine helper and
possibly adding some helpers to allow usage with spin batches.

We want to get a better view of usability in future IGT code and I think
the series needs to be complete in this respect.

Regards,

Tvrtko

> +
> + ctx_engine = (struct i915_context_param_engines *) buff;
> +
> + ctx_param.ctx_id = ctx_id;
> + ctx_param.param = I915_CONTEXT_PARAM_ENGINES;
> +
> + ctx_engine->extensions = 0;
> + for (i = 0, e2 = intel_active_engines2; e2->name; i++, e2++) {
> + ctx_engine->class_instance[i].engine_class = e2->class;
> + ctx_engine->class_instance[i].engine_instance = e2->instance;
> + }
> +
> + ctx_param.size = offsetof(typeof(*ctx_engine), class_instance[i + 1]);
> + ctx_param.value = to_user_pointer(ctx_engine);
> +
> + gem_context_set_param(fd, &ctx_param);
> +
> + ctx_is_set = true;
> +}
> +
> +/*
> + * Initializes the list of engines.
> + *
> + * Returns:
> + *
> + * - 0 in case of success and the get/set_param ioctls are implemented
> + * - -ENODEV in case of success but I915_CONTEXT_PARAM_ENGINES is not
> + * implemented in DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM ioctl.
> + */
> +static int init_engine_list(int fd)
> +{
> + const char *class_names[] = { "rcs", "bcs", "vcs", "vecs" };
> + struct drm_i915_query_engine_info *query_engine;
> + unsigned char query_buffer[SIZEOF_QUERY] = { };
> + struct drm_i915_gem_context_param ctx_param = {
> + .param = I915_CONTEXT_PARAM_ENGINES,
> + };
> + int i;
> +
> + /* the list is already initialized */
> + if (intel_active_engines2)
> + return 0;
> +
> + /*
> + * We check first whether the I915_CONTEXT_PARAM_ENGINES parameter is
> + * supported by the running kernel. If not, __gem_context_get_param()
> + * will return -EINVAL which, at this point, is not necessarily a
> + * failure but it means that we need to fall beck to polling the engines
> + * directly from intel_execution_engines2[].
> + *
> + * We will return -ENODEV with the meaning of missing interface
> + */
> + if (__gem_context_get_param(fd, &ctx_param))
> + return -ENODEV;
> +
> + query_engine = (struct drm_i915_query_engine_info *) query_buffer;
> + query_engines(fd, query_engine);
> +
> + intel_active_engines2 = malloc((query_engine->num_engines + 1) *
> + sizeof(*intel_active_engines2));
> + igt_assert(intel_active_engines2);
> +
> + for (i = 0; i < query_engine->num_engines; i++) {
> + char *name;
> + __u16 class = query_engine->engines[i].engine_class;
> + __u16 instance = query_engine->engines[i].engine_instance;
> +
> + intel_active_engines2[i].class = class;
> + intel_active_engines2[i].instance = instance;
> +
> + /* if we don't recognise the class, then we mark it as "unk" */
> + if (class >= ARRAY_SIZE(class_names))
> + igt_assert(asprintf(&name, "unk-%d:%d",
> + class, instance) > 0);
> + else
> + igt_assert(asprintf(&name, "%s%d",
> + class_names[class], instance) > 0);
> +
> + intel_active_engines2[i].name = name;
> + }
> +
> + /* NULL value sentinel */
> + intel_active_engines2[i].name = NULL;
> +
> + return 0;
> +}
> +
> +struct intel_execution_engine2 *get_active_engines(int fd)
> +{
> + if (init_engine_list(fd))
> + return NULL;
> +
> + return intel_active_engines2;
> +}
> +
> +struct intel_execution_engine2 *__gem_prepare_context_engines(int fd,
> + uint32_t ctx_id)
> +{
> + struct intel_execution_engine2 *active_engines = get_active_engines(fd);
> +
> + if (!active_engines) {
> + igt_debug("using pre-allocated engine list\n");
> + return intel_execution_engines2;
> + }
> +
> + set_ctx_param_engines(fd, ctx_id);
> +
> + return intel_active_engines2;
> +}
> +
> +void igt_require_gem_engine_list(int fd)
> +{
> + igt_require(!init_engine_list(fd));
> +}
> diff --git a/lib/i915/gem_engine_topology.h b/lib/i915/gem_engine_topology.h
> new file mode 100644
> index 000000000000..88e902610ad8
> --- /dev/null
> +++ b/lib/i915/gem_engine_topology.h
> @@ -0,0 +1,33 @@
> +/*
> + * 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
> +
> +struct intel_execution_engine2 *get_active_engines(int fd);
> +struct intel_execution_engine2 *__gem_prepare_context_engines(int fd,
> + uint32_t ctx_id);
> +
> +void igt_require_gem_engine_list(int fd);
> +
> +#endif /* GEM_ENGINE_TOPOLOGY_H */
> diff --git a/lib/igt_gt.c b/lib/igt_gt.c
> index c98a7553b7fe..54c71e5e7186 100644
> --- a/lib/igt_gt.c
> +++ b/lib/igt_gt.c
> @@ -577,7 +577,7 @@ bool gem_can_store_dword(int fd, unsigned int engine)
> return true;
> }
>
> -const struct intel_execution_engine2 intel_execution_engines2[] = {
> +struct intel_execution_engine2 intel_execution_engines2[] = {
> { "rcs0", I915_ENGINE_CLASS_RENDER, 0 },
> { "bcs0", I915_ENGINE_CLASS_COPY, 0 },
> { "vcs0", I915_ENGINE_CLASS_VIDEO, 0 },
> diff --git a/lib/igt_gt.h b/lib/igt_gt.h
> index 54e95da98084..f4bd6c22a81a 100644
> --- a/lib/igt_gt.h
> +++ b/lib/igt_gt.h
> @@ -91,7 +91,7 @@ bool gem_ring_has_physical_engine(int fd, unsigned int ring);
>
> bool gem_can_store_dword(int fd, unsigned int engine);
>
> -extern const struct intel_execution_engine2 {
> +extern struct intel_execution_engine2 {
> const char *name;
> int class;
> int instance;
> diff --git a/lib/meson.build b/lib/meson.build
> index 0eb5585d72b9..3cc52f97c8bf 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',
>