drm/gpusvm: pull out drm_gpusvm_pages substructure

Pull the pages stuff from the svm range into its own substructure, with
the idea of having the main pages related routines, like get_pages(),
unmap_pages() and free_pages() all operating on some lower level
structures, which can then be re-used for stuff like userptr.

v2:
  - Move seq into pages struct (Matt B)
v3:
  - Small kernel-doc fixes

Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250828142430.615826-13-matthew.auld@intel.com

1 files changed, 31 insertions, 17 deletions

diff --git a/include/drm/drm_gpusvm.h b/include/drm/drm_gpusvm.h
index 0e336148309d..1ee4188c3067 100644
--- a/include/drm/drm_gpusvm.h
+++ b/include/drm/drm_gpusvm.h
@@ -106,16 +106,16 @@ struct drm_gpusvm_notifier {
 };
 
 /**
- * struct drm_gpusvm_range_flags - Structure representing a GPU SVM range flags
+ * struct drm_gpusvm_pages_flags - Structure representing a GPU SVM pages flags
  *
- * @migrate_devmem: Flag indicating whether the range can be migrated to device memory
- * @unmapped: Flag indicating if the range has been unmapped
- * @partial_unmap: Flag indicating if the range has been partially unmapped
- * @has_devmem_pages: Flag indicating if the range has devmem pages
- * @has_dma_mapping: Flag indicating if the range has a DMA mapping
- * @__flags: Flags for range in u16 form (used for READ_ONCE)
+ * @migrate_devmem: Flag indicating whether the pages can be migrated to device memory
+ * @unmapped: Flag indicating if the pages has been unmapped
+ * @partial_unmap: Flag indicating if the pages has been partially unmapped
+ * @has_devmem_pages: Flag indicating if the pages has devmem pages
+ * @has_dma_mapping: Flag indicating if the pages has a DMA mapping
+ * @__flags: Flags for pages in u16 form (used for READ_ONCE)
  */
-struct drm_gpusvm_range_flags {
+struct drm_gpusvm_pages_flags {
 	union {
 		struct {
 			/* All flags below must be set upon creation */
@@ -131,6 +131,27 @@ struct drm_gpusvm_range_flags {
 };
 
 /**
+ * struct drm_gpusvm_pages - Structure representing a GPU SVM mapped pages
+ *
+ * @dma_addr: Device address array
+ * @dpagemap: The struct drm_pagemap of the device pages we're dma-mapping.
+ *            Note this is assuming only one drm_pagemap per range is allowed.
+ * @notifier_seq: Notifier sequence number of the range's pages
+ * @flags: Flags for range
+ * @flags.migrate_devmem: Flag indicating whether the range can be migrated to device memory
+ * @flags.unmapped: Flag indicating if the range has been unmapped
+ * @flags.partial_unmap: Flag indicating if the range has been partially unmapped
+ * @flags.has_devmem_pages: Flag indicating if the range has devmem pages
+ * @flags.has_dma_mapping: Flag indicating if the range has a DMA mapping
+ */
+struct drm_gpusvm_pages {
+	struct drm_pagemap_addr *dma_addr;
+	struct drm_pagemap *dpagemap;
+	unsigned long notifier_seq;
+	struct drm_gpusvm_pages_flags flags;
+};
+
+/**
  * struct drm_gpusvm_range - Structure representing a GPU SVM range
  *
  * @gpusvm: Pointer to the GPU SVM structure
@@ -138,11 +159,7 @@ struct drm_gpusvm_range_flags {
  * @refcount: Reference count for the range
  * @itree: Interval tree node for the range (inserted in GPU SVM notifier)
  * @entry: List entry to fast interval tree traversal
- * @notifier_seq: Notifier sequence number of the range's pages
- * @dma_addr: Device address array
- * @dpagemap: The struct drm_pagemap of the device pages we're dma-mapping.
- *            Note this is assuming only one drm_pagemap per range is allowed.
- * @flags: Flags for range
+ * @pages: The pages for this range.
  *
  * This structure represents a GPU SVM range used for tracking memory ranges
  * mapped in a DRM device.
@@ -153,10 +170,7 @@ struct drm_gpusvm_range {
 	struct kref refcount;
 	struct interval_tree_node itree;
 	struct list_head entry;
-	unsigned long notifier_seq;
-	struct drm_pagemap_addr *dma_addr;
-	struct drm_pagemap *dpagemap;
-	struct drm_gpusvm_range_flags flags;
+	struct drm_gpusvm_pages pages;
 };
 
 /**