Currently, the Devres<T> container uses devm_add_action() to register a
devres callback.

devm_add_action() allocates a struct action_devres, which on top of
struct devres_node, just keeps a data pointer and release function
pointer.

This is an unnecessary indirection, given that analogous to struct
devres, the Devres<T> container can just embed a struct devres_node
directly without an additional allocation.

In contrast to struct devres, we don't need to force an alignment of
ARCH_DMA_MINALIGN (as struct devres does to account for the worst case)
since we have generics in Rust. I.e. the compiler already ensures
correct alignment of the embedded T in Devres<T>.

Thus, get rid of devm_add_action() and instead embed a struct
devres_node directly.

This patch series is based on [1] and [2].

[1] https://lore.kernel.org/lkml/20260205222529.91465-1-dakr@kernel.org/
[2] https://lore.kernel.org/lkml/20260202235210.55176-1-dakr@kernel.org/

Danilo Krummrich (5):
  devres: move struct devres_node into base.h
  devres: export devres_node_init() and devres_node_add()
  devres: add devres_node_remove()
  devres: rename and export set_node_dbginfo()
  rust: devres: embed struct devres_node directly

 drivers/base/base.h   |  18 +++++++
 drivers/base/devres.c |  54 +++++++++++--------
 rust/kernel/devres.rs | 123 ++++++++++++++++++++++++++----------------
 3 files changed, 127 insertions(+), 68 deletions(-)


base-commit: c98d3727720db5f74bf40a8cd1c2da05081845ee
-- 
2.52.0