On 5/25/22 20:43, Matthew Auld wrote:
Userspace wants to know the size of CPU visible portion of device
local-memory, and on small BAR devices the probed_size is no longer
enough. In Vulkan, for example, it would like to know the size in bytes
for CPU visible VkMemoryHeap. We already track the io_size for each
region, so it's just case of plumbing that through to the region query.
Nit: so plumb that through (imperative)
Testcase: igt@i915_query@query-regions-sanity-check
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Cc: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Cc: Jon Bloomfield <jon.bloomfield@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Jordan Justen <jordan.l.justen@xxxxxxxxx>
Cc: Kenneth Graunke <kenneth@xxxxxxxxxxxxx>
Cc: Akeem G Abodunrin <akeem.g.abodunrin@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_query.c | 6 +++
include/uapi/drm/i915_drm.h | 74 +++++++++++++++++--------------
2 files changed, 47 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_query.c b/drivers/gpu/drm/i915/i915_query.c
index 7584cec53d5d..9aa0b28aa6ee 100644
--- a/drivers/gpu/drm/i915/i915_query.c
+++ b/drivers/gpu/drm/i915/i915_query.c
@@ -496,6 +496,12 @@ static int query_memregion_info(struct drm_i915_private *i915,
info.region.memory_class = mr->type;
info.region.memory_instance = mr->instance;
info.probed_size = mr->total;
+
+ if (mr->type == INTEL_MEMORY_LOCAL)
+ info.probed_cpu_visible_size = mr->io_size;
+ else
+ info.probed_cpu_visible_size = mr->total;
+
info.unallocated_size = mr->avail;
if (__copy_to_user(info_ptr, &info, sizeof(info)))
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index de49b68b4fc8..9df419a45244 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -3207,36 +3207,6 @@ struct drm_i915_gem_memory_class_instance {
* struct drm_i915_memory_region_info - Describes one region as known to the
* driver.
*
- * Note that we reserve some stuff here for potential future work. As an example
- * we might want expose the capabilities for a given region, which could include
- * things like if the region is CPU mappable/accessible, what are the supported
- * mapping types etc.
- *
- * Note that to extend struct drm_i915_memory_region_info and struct
- * drm_i915_query_memory_regions in the future the plan is to do the following:
- *
- * .. code-block:: C
- *
- * struct drm_i915_memory_region_info {
- * struct drm_i915_gem_memory_class_instance region;
- * union {
- * __u32 rsvd0;
- * __u32 new_thing1;
- * };
- * ...
- * union {
- * __u64 rsvd1[8];
- * struct {
- * __u64 new_thing2;
- * __u64 new_thing3;
- * ...
- * };
- * };
- * };
- *
- * With this things should remain source compatible between versions for
- * userspace, even as we add new fields.
- *
* Note this is using both struct drm_i915_query_item and struct drm_i915_query.
* For this new query we are adding the new query id DRM_I915_QUERY_MEMORY_REGIONS
* at &drm_i915_query_item.query_id.
@@ -3248,14 +3218,52 @@ struct drm_i915_memory_region_info {
/** @rsvd0: MBZ */
__u32 rsvd0;
- /** @probed_size: Memory probed by the driver (-1 = unknown) */
+ /**
+ * @probed_size: Memory probed by the driver (-1 = unknown)
+ *
+ * Note that it should not be possible to ever encounter a zero value
+ * here, also note that no current region type will ever return -1 here.
+ * Although for future region types, this might be a possibility. The
+ * same applies to the other size fields.
+ */
__u64 probed_size;
/** @unallocated_size: Estimate of memory remaining (-1 = unknown) */
__u64 unallocated_size;
- /** @rsvd1: MBZ */
- __u64 rsvd1[8];
+ union {
+ /** @rsvd1: MBZ */
+ __u64 rsvd1[8];
+ struct {
+ /**
+ * @probed_cpu_visible_size: Memory probed by the driver
+ * that is CPU accessible. (-1 = unknown).
+ *
+ * This will be always be <= @probed_size, and the
+ * remainder (if there is any) will not be CPU
+ * accessible.
+ *
+ * On systems without small BAR, the @probed_size will
+ * always equal the @probed_cpu_visible_size, since all
+ * of it will be CPU accessible.
+ *
+ * Note this is only tracked for
+ * I915_MEMORY_CLASS_DEVICE regions (for other types the
+ * value here will always equal the @probed_size).
+ *
+ * Note that if the value returned here is zero, then
+ * this must be an old kernel which lacks the relevant
+ * small-bar uAPI support (including
+ * I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS), but on
+ * such systems we should never actually end up with a
+ * small BAR configuration, assuming we are able to load
+ * the kernel module. Hence it should be safe to treat
+ * this the same as when @probed_cpu_visible_size ==
+ * @probed_size.
+ */
+ __u64 probed_cpu_visible_size;
+ };
+ };
};
/**
Reviewed-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
