[Intel-gfx] [PATCH v6] drm/i915: Engine discovery query
Tvrtko Ursulin
tursulin at ursulin.net
Thu Oct 4 10:51:18 UTC 2018
From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Engine discovery query allows userspace to enumerate engines, probe their
configuration features, all without needing to maintain the internal PCI
ID based database.
A new query for the generic i915 query ioctl is added named
DRM_I915_QUERY_ENGINE_INFO, together with accompanying structure
drm_i915_query_engine_info. The address of latter should be passed to the
kernel in the query.data_ptr field, and should be large enough for the
kernel to fill out all known engines as struct drm_i915_engine_info
elements trailing the query.
As with other queries, setting the item query length to zero allows
userspace to query minimum required buffer size.
Enumerated engines have common type mask which can be used to query all
hardware engines, versus engines userspace can submit to using the execbuf
uAPI.
Engines also have capabilities which are per engine class namespace of
bits describing features not present on all engine instances.
v2:
* Fixed HEVC assignment.
* Reorder some fields, rename type to flags, increase width. (Lionel)
* No need to allocate temporary storage if we do it engine by engine.
(Lionel)
v3:
* Describe engine flags and mark mbz fields. (Lionel)
* HEVC only applies to VCS.
v4:
* Squash SFC flag into main patch.
* Tidy some comments.
v5:
* Add uabi_ prefix to engine capabilities. (Chris Wilson)
* Report exact size of engine info array. (Chris Wilson)
* Drop the engine flags. (Joonas Lahtinen)
* Added some more reserved fields.
* Move flags after class/instance.
v6:
* Do not check engine info array was zeroed by userspace but zero the
unused fields for them instead.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jon Bloomfield <jon.bloomfield at intel.com>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin at intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Tony Ye <tony.ye at intel.com>
---
drivers/gpu/drm/i915/i915_query.c | 56 +++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_engine_cs.c | 12 ++++++
drivers/gpu/drm/i915/intel_ringbuffer.h | 3 ++
include/uapi/drm/i915_drm.h | 47 +++++++++++++++++++++
4 files changed, 118 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_query.c b/drivers/gpu/drm/i915/i915_query.c
index 5821002cad42..5ac8ef9f5de4 100644
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -84,9 +84,65 @@ static int query_topology_info(struct drm_i915_private *dev_priv,
return total_length;
}
+static int
+query_engine_info(struct drm_i915_private *i915,
+ struct drm_i915_query_item *query_item)
+{
+ struct drm_i915_query_engine_info __user *query_ptr =
+ u64_to_user_ptr(query_item->data_ptr);
+ struct drm_i915_engine_info __user *info_ptr = &query_ptr->engines[0];
+ struct drm_i915_query_engine_info query;
+ struct drm_i915_engine_info info = { };
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ int len;
+
+ if (query_item->flags)
+ return -EINVAL;
+
+ len = 0;
+ for_each_engine(engine, i915, id)
+ len++;
+ len *= sizeof(struct drm_i915_engine_info);
+ len += sizeof(struct drm_i915_query_engine_info);
+
+ if (!query_item->length)
+ return len;
+ else if (query_item->length < len)
+ return -EINVAL;
+
+ if (copy_from_user(&query, query_ptr, sizeof(query)))
+ return -EFAULT;
+
+ if (query.num_engines || query.rsvd[0] || query.rsvd[1] ||
+ query.rsvd[2])
+ return -EINVAL;
+
+ if (!access_ok(VERIFY_WRITE, query_ptr, query_item->length))
+ return -EFAULT;
+
+ for_each_engine(engine, i915, id) {
+ info.class = engine->uabi_class;
+ info.instance = engine->instance;
+ info.capabilities = engine->uabi_capabilities;
+
+ if (__copy_to_user(info_ptr, &info, sizeof(info)))
+ return -EFAULT;
+
+ query.num_engines++;
+ info_ptr++;
+ }
+
+ if (__copy_to_user(query_ptr, &query, sizeof(query)))
+ return -EFAULT;
+
+ return len;
+}
+
static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
struct drm_i915_query_item *query_item) = {
query_topology_info,
+ query_engine_info,
};
int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 1c6143bdf5a4..134f0cec724c 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -298,6 +298,18 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
engine->uabi_id = info->uabi_id;
engine->uabi_class = intel_engine_classes[info->class].uabi_class;
+ if (engine->class == VIDEO_DECODE_CLASS) {
+ /* HEVC support is present only on vcs0. */
+ if (INTEL_GEN(dev_priv) >= 8 && info->instance == 0)
+ engine->uabi_capabilities =
+ I915_VCS_CLASS_CAPABILITY_HEVC;
+
+ /* SFC support is wired only to even VCS instances. */
+ if (INTEL_GEN(dev_priv) >= 9 && !(info->instance & 1))
+ engine->uabi_capabilities |=
+ I915_VCS_CLASS_CAPABILITY_SFC;
+ }
+
engine->context_size = __intel_engine_context_size(dev_priv,
engine->class);
if (WARN_ON(engine->context_size > BIT(20)))
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index f6ec48a75a69..9dc738f1b175 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -370,6 +370,9 @@ struct intel_engine_cs {
u8 class;
u8 instance;
+
+ u32 uabi_capabilities;
+
u32 context_size;
u32 mmio_base;
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 298b2e197744..3b0373fb0a93 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1650,6 +1650,7 @@ struct drm_i915_perf_oa_config {
struct drm_i915_query_item {
__u64 query_id;
#define DRM_I915_QUERY_TOPOLOGY_INFO 1
+#define DRM_I915_QUERY_ENGINE_INFO 2
/*
* When set to zero by userspace, this is filled with the size of the
@@ -1747,6 +1748,52 @@ struct drm_i915_query_topology_info {
__u8 data[];
};
+/**
+ * struct drm_i915_engine_info
+ *
+ * Describes one engine known to the driver, whether or not it is an user-
+ * accessible or hardware only engine, and what are it's capabilities where
+ * applicable.
+ */
+struct drm_i915_engine_info {
+ /** Engine class as in enum drm_i915_gem_engine_class. */
+ __u16 class;
+
+ /** Engine instance number. */
+ __u16 instance;
+
+ /** Reserved field must be cleared to zero. */
+ __u32 rsvd0;
+
+ /** Engine flags. */
+ __u64 flags;
+
+ /** Capabilities of this engine. */
+ __u64 capabilities;
+#define I915_VCS_CLASS_CAPABILITY_HEVC (1 << 0)
+#define I915_VCS_CLASS_CAPABILITY_SFC (1 << 1)
+
+ /** Reserved fields must be cleared to zero. */
+ __u64 rsvd1[4];
+};
+
+/**
+ * struct drm_i915_query_engine_info
+ *
+ * Engine info query enumerates all engines known to the driver by filling in
+ * an array of struct drm_i915_engine_info structures.
+ */
+struct drm_i915_query_engine_info {
+ /** Number of struct drm_i915_engine_info structs following. */
+ __u32 num_engines;
+
+ /** MBZ */
+ __u32 rsvd[3];
+
+ /** Marker for drm_i915_engine_info structures. */
+ struct drm_i915_engine_info engines[];
+};
+
#if defined(__cplusplus)
}
#endif
--
2.17.1
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