On Fri, Apr 16, 2021 at 12:25 AM Ian Romanick idr@freedesktop.org wrote:
On 4/15/21 8:59 AM, Matthew Auld wrote:
Add a note about the two-step process.
Suggested-by: Daniel Vetter daniel@ffwll.ch Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Jordan Justen jordan.l.justen@intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Kenneth Graunke kenneth@whitecape.org Cc: Jason Ekstrand jason@jlekstrand.net Cc: Dave Airlie airlied@gmail.com Cc: dri-devel@lists.freedesktop.org Cc: mesa-dev@lists.freedesktop.org
include/uapi/drm/i915_drm.h | 57 ++++++++++++++++++++++++++++++------- 1 file changed, 46 insertions(+), 11 deletions(-)
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index d9c954a5a456..ef36f1a0adde 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -2210,14 +2210,23 @@ struct drm_i915_perf_oa_config { __u64 flex_regs_ptr; };
+/**
- struct drm_i915_query_item - An individual query for the kernel to process.
- The behaviour is determined by the @query_id. Note that exactly what
Since we just had a big discussion about this on mesa-dev w.r.t. Mesa code and documentation... does the kernel have a policy about which flavor (pun intended) of English should be used?
I'm not finding it documented in https://dri.freedesktop.org/docs/drm/doc-guide/sphinx.html but I thought we've discussed it. Adding linux-doc and Jon Corbet. -Daniel
- @data_ptr is also depends on the specific @query_id.
- */
struct drm_i915_query_item {
/** @query_id: The id for this query */ __u64 query_id;#define DRM_I915_QUERY_TOPOLOGY_INFO 1 #define DRM_I915_QUERY_ENGINE_INFO 2 #define DRM_I915_QUERY_PERF_CONFIG 3 /* Must be kept compact -- no holes and well documented */
/*
/*** @length:* * When set to zero by userspace, this is filled with the size of the * data to be written at the data_ptr pointer. The kernel sets this * value to a negative value to signal an error on a particular query@@ -2225,21 +2234,26 @@ struct drm_i915_query_item { */ __s32 length;
/*
/*** @flags:* * When query_id == DRM_I915_QUERY_TOPOLOGY_INFO, must be 0. * * When query_id == DRM_I915_QUERY_PERF_CONFIG, must be one of the
* following :* - DRM_I915_QUERY_PERF_CONFIG_LIST* - DRM_I915_QUERY_PERF_CONFIG_DATA_FOR_UUID* - DRM_I915_QUERY_PERF_CONFIG_FOR_UUID
* following:** - DRM_I915_QUERY_PERF_CONFIG_LIST* - DRM_I915_QUERY_PERF_CONFIG_DATA_FOR_UUID* - DRM_I915_QUERY_PERF_CONFIG_FOR_UUID */ __u32 flags;#define DRM_I915_QUERY_PERF_CONFIG_LIST 1 #define DRM_I915_QUERY_PERF_CONFIG_DATA_FOR_UUID 2 #define DRM_I915_QUERY_PERF_CONFIG_DATA_FOR_ID 3
/*
/*** @data_ptr:* * Data will be written at the location pointed by data_ptr when the * value of length matches the length of the data to be written by the * kernel.@@ -2247,16 +2261,37 @@ struct drm_i915_query_item { __u64 data_ptr; };
+/**
- struct drm_i915_query - Supply an array of drm_i915_query_item for the kernel
- to fill out.
- Note that this is generally a two step process for each drm_i915_query_item
- in the array:
- 1.) Call the DRM_IOCTL_I915_QUERY, giving it our array of
- drm_i915_query_item, with drm_i915_query_item.size set to zero. The
- kernel will then fill in the size, in bytes, which tells userspace how
- memory it needs to allocate for the blob(say for an array of
- properties).
- 2.) Next we call DRM_IOCTL_I915_QUERY again, this time with the
- drm_i915_query_item.data_ptr equal to our newly allocated blob. Note
- that the i915_query_item.size should still be the same as what the
- kernel previously set. At this point the kernel can fill in the blob.
- */
struct drm_i915_query {
/** @num_items: The number of elements in the @items_ptr array */ __u32 num_items;
/** Unused for now. Must be cleared to zero.
/*** @flags: Unused for now. Must be cleared to zero. */ __u32 flags;
/** This points to an array of num_items drm_i915_query_item structures.
/*** @items_ptr: This points to an array of num_items drm_i915_query_item* structures. */ __u64 items_ptr;};
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