Re: [PATCH v2 01/12] drm/doc: add rfc section for small BAR uapi

2022-06-22 Thread Thomas Hellström



On 6/21/22 12:44, Matthew Auld wrote:

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)
v3:
   - Drop the vma query for now.
   - Add unallocated_cpu_visible_size as part of the region query.
   - Improve the docs some more, including documenting the expected
 behaviour on older kernels, since this came up in some offline
 discussion.
v4:
   - Various improvements all over. (Tvrtko)

v5:
   - Include newer integrated platforms when applying the non-recoverable
 context and error capture restriction. (Thomas)

Signed-off-by: Matthew Auld 
Cc: Thomas Hellström 
Cc: Lionel Landwerlin 
Cc: Tvrtko Ursulin 
Cc: Jon Bloomfield 
Cc: Daniel Vetter 
Cc: Jordan Justen 
Cc: Kenneth Graunke 
Cc: Akeem G Abodunrin 
Cc: mesa-dev@lists.freedesktop.org
Acked-by: Tvrtko Ursulin 
Acked-by: Akeem G Abodunrin 


Reviewed-by: Thomas Hellström 




---
  Documentation/gpu/rfc/i915_small_bar.h   | 189 +++
  Documentation/gpu/rfc/i915_small_bar.rst |  47 ++
  Documentation/gpu/rfc/index.rst  |   4 +
  3 files changed, 240 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 ..752bb2ceb399
--- /dev/null
+++ b/Documentation/gpu/rfc/i915_small_bar.h
@@ -0,0 +1,189 @@
+/**
+ * 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)
+*
+* 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)
+*
+* Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable accounting.
+* Without this (or if this is an older kernel) the value here will
+* always equal the @probed_size. Note this is only currently tracked
+* for I915_MEMORY_CLASS_DEVICE regions (for other types the value here
+* will always equal the @probed_size).
+*/
+   __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.
+*
+* 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;
+
+   /**
+* @unallocated_cpu_visible_size: Estimate of CPU
+* visible 

Re: [PATCH v2 01/12] drm/doc: add rfc section for small BAR uapi

2022-06-21 Thread Jordan Justen
On 2022-06-21 11:31:39, Lionel Landwerlin wrote:
> On 21/06/2022 13:44, Matthew Auld wrote:
> > 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)
> > v3:
> >- Drop the vma query for now.
> >- Add unallocated_cpu_visible_size as part of the region query.
> >- Improve the docs some more, including documenting the expected
> >  behaviour on older kernels, since this came up in some offline
> >  discussion.
> > v4:
> >- Various improvements all over. (Tvrtko)
> >
> > v5:
> >- Include newer integrated platforms when applying the non-recoverable
> >  context and error capture restriction. (Thomas)
> >
> > Signed-off-by: Matthew Auld 
> > Cc: Thomas Hellström 
> > Cc: Lionel Landwerlin 
> > Cc: Tvrtko Ursulin 
> > Cc: Jon Bloomfield 
> > Cc: Daniel Vetter 
> > Cc: Jordan Justen 
> > Cc: Kenneth Graunke 
> > Cc: Akeem G Abodunrin 
> > Cc: mesa-dev@lists.freedesktop.org
> > Acked-by: Tvrtko Ursulin 
> > Acked-by: Akeem G Abodunrin 
> 
> 
> With Jordan with have changes for Anv/Iris : 
> https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16739
> 
> Acked-by: Lionel Landwerlin 
> 

Acked-by: Jordan Justen 


Re: [PATCH v2 01/12] drm/doc: add rfc section for small BAR uapi

2022-06-21 Thread Lionel Landwerlin

On 21/06/2022 13:44, Matthew Auld wrote:

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)
v3:
   - Drop the vma query for now.
   - Add unallocated_cpu_visible_size as part of the region query.
   - Improve the docs some more, including documenting the expected
 behaviour on older kernels, since this came up in some offline
 discussion.
v4:
   - Various improvements all over. (Tvrtko)

v5:
   - Include newer integrated platforms when applying the non-recoverable
 context and error capture restriction. (Thomas)

Signed-off-by: Matthew Auld 
Cc: Thomas Hellström 
Cc: Lionel Landwerlin 
Cc: Tvrtko Ursulin 
Cc: Jon Bloomfield 
Cc: Daniel Vetter 
Cc: Jordan Justen 
Cc: Kenneth Graunke 
Cc: Akeem G Abodunrin 
Cc: mesa-dev@lists.freedesktop.org
Acked-by: Tvrtko Ursulin 
Acked-by: Akeem G Abodunrin 



With Jordan with have changes for Anv/Iris : 
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16739


Acked-by: Lionel Landwerlin 



---
  Documentation/gpu/rfc/i915_small_bar.h   | 189 +++
  Documentation/gpu/rfc/i915_small_bar.rst |  47 ++
  Documentation/gpu/rfc/index.rst  |   4 +
  3 files changed, 240 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 ..752bb2ceb399
--- /dev/null
+++ b/Documentation/gpu/rfc/i915_small_bar.h
@@ -0,0 +1,189 @@
+/**
+ * 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)
+*
+* 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)
+*
+* Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable accounting.
+* Without this (or if this is an older kernel) the value here will
+* always equal the @probed_size. Note this is only currently tracked
+* for I915_MEMORY_CLASS_DEVICE regions (for other types the value here
+* will always equal the @probed_size).
+*/
+   __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.
+*
+* 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;
+
+   /**
+