cgroup/dmem: Introduce struct dmem_cgroup_init for region initialization

Replace the bare u64 size argument to dmem_cgroup_register_region() and
drmm_cgroup_register_region() with a const struct dmem_cgroup_init *
pointer. The struct currently carries only the size field, but using a
struct makes the API extensible: future callers can supply additional
initialization parameters without adding more positional arguments.

Update all in-tree callers (amdgpu, xe) to use a compound-literal
initializer.

v5:
- Commit introduced.

Assisted-by: GitHub_Copilot:claude-sonnet-4.6
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Tested-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://patch.msgid.link/20260725100036.2372-3-thomas.hellstrom@linux.intel.com
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

1 files changed, 6 insertions, 4 deletions

diff --git a/kernel/cgroup/dmem.c b/kernel/cgroup/dmem.c
index 1af08b0464b8..aea21e39180a 100644
--- a/kernel/cgroup/dmem.c
+++ b/kernel/cgroup/dmem.c
@@ -502,7 +502,7 @@ EXPORT_SYMBOL_GPL(dmem_cgroup_unregister_region);
 
 /**
  * dmem_cgroup_register_region() - Register a regions for dev cgroup.
- * @size: Size of region to register, in bytes.
+ * @init: Initialization parameters for the region.
  * @fmt: Region parameters to register
  *
  * This function registers a node in the dmem cgroup with the
@@ -511,13 +511,15 @@ EXPORT_SYMBOL_GPL(dmem_cgroup_unregister_region);
  *
  * Return: NULL or a struct on success, PTR_ERR on failure.
  */
-struct dmem_cgroup_region *dmem_cgroup_register_region(u64 size, const char *fmt, ...)
+struct dmem_cgroup_region *
+dmem_cgroup_register_region(const struct dmem_cgroup_init *init,
+			    const char *fmt, ...)
 {
 	struct dmem_cgroup_region *ret;
 	char *region_name;
 	va_list ap;
 
-	if (!size)
+	if (!init || !init->size)
 		return NULL;
 
 	va_start(ap, fmt);
@@ -534,7 +536,7 @@ struct dmem_cgroup_region *dmem_cgroup_register_region(u64 size, const char *fmt
 
 	INIT_LIST_HEAD(&ret->pools);
 	ret->name = region_name;
-	ret->size = size;
+	ret->size = init->size;
 	kref_init(&ret->ref);
 
 	spin_lock(&dmemcg_lock);