From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- Documentation/crypto/crypto_engine.rst | 80 ++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 Documentation/crypto/crypto_engine.rst (limited to 'Documentation/crypto/crypto_engine.rst') diff --git a/Documentation/crypto/crypto_engine.rst b/Documentation/crypto/crypto_engine.rst new file mode 100644 index 000000000..7ef850e28 --- /dev/null +++ b/Documentation/crypto/crypto_engine.rst @@ -0,0 +1,80 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Crypto Engine +============= + +Overview +-------- +The crypto engine (CE) API is a crypto queue manager. + +Requirement +----------- +You must put, at the start of your transform context your_tfm_ctx, the structure +crypto_engine: + +:: + + struct your_tfm_ctx { + struct crypto_engine engine; + ... + }; + +The crypto engine only manages asynchronous requests in the form of +crypto_async_request. It cannot know the underlying request type and thus only +has access to the transform structure. It is not possible to access the context +using container_of. In addition, the engine knows nothing about your +structure "``struct your_tfm_ctx``". The engine assumes (requires) the placement +of the known member ``struct crypto_engine`` at the beginning. + +Order of operations +------------------- +You are required to obtain a struct crypto_engine via ``crypto_engine_alloc_init()``. +Start it via ``crypto_engine_start()``. When finished with your work, shut down the +engine using ``crypto_engine_stop()`` and destroy the engine with +``crypto_engine_exit()``. + +Before transferring any request, you have to fill the context enginectx by +providing functions for the following: + +* ``prepare_cipher_request``/``prepare_hash_request``: Called before each + corresponding request is performed. If some processing or other preparatory + work is required, do it here. + +* ``unprepare_cipher_request``/``unprepare_hash_request``: Called after each + request is handled. Clean up / undo what was done in the prepare function. + +* ``cipher_one_request``/``hash_one_request``: Handle the current request by + performing the operation. + +Note that these functions access the crypto_async_request structure +associated with the received request. You are able to retrieve the original +request by using: + +:: + + container_of(areq, struct yourrequesttype_request, base); + +When your driver receives a crypto_request, you must to transfer it to +the crypto engine via one of: + +* crypto_transfer_aead_request_to_engine() + +* crypto_transfer_akcipher_request_to_engine() + +* crypto_transfer_hash_request_to_engine() + +* crypto_transfer_kpp_request_to_engine() + +* crypto_transfer_skcipher_request_to_engine() + +At the end of the request process, a call to one of the following functions is needed: + +* crypto_finalize_aead_request() + +* crypto_finalize_akcipher_request() + +* crypto_finalize_hash_request() + +* crypto_finalize_kpp_request() + +* crypto_finalize_skcipher_request() -- cgit v1.3.1