[Patch v3] Add uAPI to query microcontroller fw version

[Vivaik Balasubrawmanian]

From: gta <gta at DUT150ADLP.fm.intel.com>

Due to a bug in GuC firmware, Mesa can't enable by default the 
usage of async compute engines feature in DG2 and newer. A new 
GuC firmware fixed the issue but until now there was no way for 
Mesa to know if KMD was running with the fixed GuC version or 
not, so this uAPI is required.

More context on the issue:
Vulkan allows applications to create types of queues: graphics, 
compute and copy. Today Intel Vulkan driver uses Render engine 
to implement all those 3 queues types.

There are a set of operations that a queue type is required to 
implement. DG2 compute engine has almost all the operations 
required by compute queue but still lacks some. So the solution 
is to send those operations not supported by compute engine to 
render engine and do some synchronization around it. But doing 
so causes the GuC scheduler to get stuck around the 
synchronization, until KMD resets the engine and bans the 
application context. This issue was root caused to a GuC 
firmware issue and was fixed in newer version.

So Mesa can't enable the "async compute" without knowing for 
sure that KMD is running with a GuC version that has the 
scheduler fix. Same will happen when Mesa start to use
copy engine.

This uAPI may be expanded in future to query other firmware 
versions too.

More information:
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23661
Mesa usage: 
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25233

v3:
- fixed redundant check with usage of copy_query_item() helper.
- reduced padding in the drm_i915_query_uc_fw_version structure.

v2:
- incorporated feedback from Tvrtko Ursulin:
  - updated patch description to clarify the use case that 
    identified this issue.
  - updated query_uc_fw_version() to use copy_query_item() helper.
  - updated the implemented GuC version query to return Submission
    version.

Cc: John Harrison <John.C.Harrison at Intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: José Roberto de Souza <jose.souza at intel.com>
Signed-off-by: Vivaik Balasubrawmanian <vivaik.balasubrawmanian at intel.com>
---
 drivers/gpu/drm/i915/i915_query.c | 33 +++++++++++++++++++++++++++++++
 include/uapi/drm/i915_drm.h       | 29 +++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_query.c b/drivers/gpu/drm/i915/i915_query.c
index 00871ef99792..e8eab0a9ecac 100644
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -551,6 +551,38 @@ static int query_hwconfig_blob(struct drm_i915_private *i915,
 	return hwconfig->size;
 }
 
+static int
+query_uc_fw_version(struct drm_i915_private *i915, struct drm_i915_query_item *query)
+{
+	struct drm_i915_query_uc_fw_version __user *query_ptr = u64_to_user_ptr(query->data_ptr);
+	size_t size = sizeof(struct drm_i915_query_uc_fw_version);
+	struct drm_i915_query_uc_fw_version resp;
+	int ret;
+
+	ret = copy_query_item(&resp, size, size, query);
+	if (ret != 0)
+		return ret;
+
+	switch (resp.uc_type) {
+	case I915_QUERY_UC_TYPE_GUC_SUBMISSION: {
+		struct intel_guc *guc = &i915->gt[0]->uc.guc;
+
+		resp.major_ver = guc->submission_version.major;
+		resp.minor_ver = guc->submission_version.minor;
+		resp.patch_ver = guc->submission_version.patch;
+		resp.branch_ver = 0;
+		break;
+	}
+	default:
+		return -EINVAL;
+	}
+
+	if (copy_to_user(query_ptr, &resp, size))
+		return -EFAULT;
+
+	return 0;
+}
+
 static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
 					struct drm_i915_query_item *query_item) = {
 	query_topology_info,
@@ -559,6 +591,7 @@ static int (* const i915_query_funcs[])(struct drm_i915_private *dev_priv,
 	query_memregion_info,
 	query_hwconfig_blob,
 	query_geometry_subslices,
+	query_uc_fw_version,
 };
 
 int i915_query_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 218edb0a96f8..385fe49a2b88 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -3013,6 +3013,7 @@ struct drm_i915_query_item {
 	 *  - %DRM_I915_QUERY_MEMORY_REGIONS (see struct drm_i915_query_memory_regions)
 	 *  - %DRM_I915_QUERY_HWCONFIG_BLOB (see `GuC HWCONFIG blob uAPI`)
 	 *  - %DRM_I915_QUERY_GEOMETRY_SUBSLICES (see struct drm_i915_query_topology_info)
+	 *  - %DRM_I915_QUERY_UC_FW_VERSION (see struct drm_i915_query_uc_fw_version)
 	 */
 	__u64 query_id;
 #define DRM_I915_QUERY_TOPOLOGY_INFO		1
@@ -3021,6 +3022,7 @@ struct drm_i915_query_item {
 #define DRM_I915_QUERY_MEMORY_REGIONS		4
 #define DRM_I915_QUERY_HWCONFIG_BLOB		5
 #define DRM_I915_QUERY_GEOMETRY_SUBSLICES	6
+#define DRM_I915_QUERY_UC_FW_VERSION        7
 /* Must be kept compact -- no holes and well documented */
 
 	/**
@@ -3213,6 +3215,33 @@ struct drm_i915_query_topology_info {
 	__u8 data[];
 };
 
+/**
+* struct drm_i915_query_uc_fw_version - query a micro-controller firmware version
+*
+* Given a uc_type this will return the major, minor, patch and branch version
+* of the micro-controller firmware.
+*/
+struct drm_i915_query_uc_fw_version {
+	/** @uc: The micro-controller type to query firmware version */
+#define I915_QUERY_UC_TYPE_GUC_SUBMISSION 0
+	__u32 uc_type;
+
+	/* @major_ver: major uc fw version */
+	__u32 major_ver;
+	/* @minor_ver: minor uc fw version */
+	__u32 minor_ver;
+	/* @patch_ver: patch uc fw version */
+	__u32 patch_ver;
+	/* @branch_ver: branch uc fw version */
+	__u32 branch_ver;
+
+	/** @pad: MBZ */
+	__u32 pad;
+
+	/** @reserved: Reserved */
+	__u64 reserved;
+};
+
 /**
  * DOC: Engine Discovery uAPI
  *

base-commit: e8d777a5e7e0ec452142ad0073022733f99c1eb7
-- 
2.34.1