Add an entry for the new uapi needed for small BAR on DG2+.
v2:
- Some spelling fixes and other small tweaks. (Akeem & Thomas)
- Rework error capture interactions, including no longer needing
NEEDS_CPU_ACCESS for objects marked for capture. (Thomas)
- Add probed_cpu_visible_size. (Lionel)
Signed-off-by: Matthew Auld
Cc: Thomas Hellström
Cc: Lionel Landwerlin
Cc: Jon Bloomfield
Cc: Daniel Vetter
Cc: Jordan Justen
Cc: Kenneth Graunke
Cc: Akeem G Abodunrin
Cc: mesa-dev@lists.freedesktop.org
---
Documentation/gpu/rfc/i915_small_bar.h | 190 +++
Documentation/gpu/rfc/i915_small_bar.rst | 58 +++
Documentation/gpu/rfc/index.rst | 4 +
3 files changed, 252 insertions(+)
create mode 100644 Documentation/gpu/rfc/i915_small_bar.h
create mode 100644 Documentation/gpu/rfc/i915_small_bar.rst
diff --git a/Documentation/gpu/rfc/i915_small_bar.h
b/Documentation/gpu/rfc/i915_small_bar.h
new file mode 100644
index ..7bfd0cf44d35
--- /dev/null
+++ b/Documentation/gpu/rfc/i915_small_bar.h
@@ -0,0 +1,190 @@
+/**
+ * struct __drm_i915_memory_region_info - Describes one region as known to the
+ * driver.
+ *
+ * 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 _i915_query_item.query_id.
+ */
+struct __drm_i915_memory_region_info {
+ /** @region: The class:instance pair encoding */
+ struct drm_i915_gem_memory_class_instance region;
+
+ /** @rsvd0: MBZ */
+ __u32 rsvd0;
+
+ /** @probed_size: Memory probed by the driver (-1 = unknown) */
+ __u64 probed_size;
+
+ /** @unallocated_size: Estimate of memory remaining (-1 = unknown) */
+ __u64 unallocated_size;
+
+ 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.
+*/
+ __u64 probed_cpu_visible_size;
+ };
+ };
+};
+
+/**
+ * struct __drm_i915_gem_create_ext - Existing gem_create behaviour, with added
+ * extension support using struct i915_user_extension.
+ *
+ * Note that new buffer flags should be added here, at least for the stuff that
+ * is immutable. Previously we would have two ioctls, one to create the object
+ * with gem_create, and another to apply various parameters, however this
+ * creates some ambiguity for the params which are considered immutable. Also
in
+ * general we're phasing out the various SET/GET ioctls.
+ */
+struct __drm_i915_gem_create_ext {
+ /**
+* @size: Requested size for the object.
+*
+* The (page-aligned) allocated size for the object will be returned.
+*
+* Note that for some devices we have might have further minimum
+* page-size restrictions(larger than 4K), like for device local-memory.
+* However in general the final size here should always reflect any
+* rounding up, if for example using the
I915_GEM_CREATE_EXT_MEMORY_REGIONS
+* extension to place the object in device local-memory.
+*/
+ __u64 size;
+ /**
+* @handle: Returned handle for the object.
+*
+* Object handles are nonzero.
+*/
+ __u32 handle;
+ /**
+* @flags: Optional flags.
+*
+* Supported values:
+*
+* I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS - Signal to the kernel that
+* the object will need to be accessed via the CPU.
+*
+* Only valid when placing objects in I915_MEMORY_CLASS_DEVICE, and
+* only strictly required on platforms where only some of the device
+* memory is directly visible or mappable through the CPU, like on DG2+.
+*
+* One of the placements MUST also be I915_MEMORY_CLASS_SYSTEM, to
+* ensure we can always spill the allocation to system memory, if we
+* can't place the object in the mappable part of
+* I915_MEMORY_CLASS_DEVICE.
+*
+* Note that since the kernel only supports flat-CCS on objects that can
+* *only* be placed in I915_MEMORY_CLASS_DEVICE, we therefore don't
+* support I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS together with
+* flat-CCS.
+*
+* Without this hint, the kernel will assume that non-mappable
+* I915_MEMORY_CLASS_DEVICE is preferred for this object. Note that the
+* kernel can still migrate the object to the mappable part, as a last
+* resort, if userspace ever CPU faults
