[v5,26/39] mldev: use C11 alignas

Message ID 1708715054-22386-27-git-send-email-roretzla@linux.microsoft.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Series use C11 alignas |


Context Check Description
ci/checkpatch success coding style OK

Commit Message

Tyler Retzlaff Feb. 23, 2024, 7:04 p.m. UTC
  The current location used for __rte_aligned(a) for alignment of types
and variables is not compatible with MSVC. There is only a single
location accepted by both toolchains.

For variables standard C11 offers alignas(a) supported by conformant
compilers i.e. both MSVC and GCC.

For types the standard offers no alignment facility that compatibly
interoperates with C and C++ but may be achieved by relocating the
placement of __rte_aligned(a) to the aforementioned location accepted
by all currently supported toolchains.

To allow alignment for both compilers do the following:

* Move __rte_aligned from the end of {struct,union} definitions to
  be between {struct,union} and tag.

  The placement between {struct,union} and the tag allows the desired
  alignment to be imparted on the type regardless of the toolchain being
  used for all of GCC, LLVM, MSVC compilers building both C and C++.

* Replace use of __rte_aligned(a) on variables/fields with alignas(a).

Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
 lib/mldev/rte_mldev.h      | 4 ++--
 lib/mldev/rte_mldev_core.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)


diff --git a/lib/mldev/rte_mldev.h b/lib/mldev/rte_mldev.h
index 27e372f..02913f3 100644
--- a/lib/mldev/rte_mldev.h
+++ b/lib/mldev/rte_mldev.h
@@ -421,7 +421,7 @@  struct rte_ml_buff_seg {
  * This structure contains data related to performing an ML operation on the buffers using
  * the model specified through model_id.
-struct rte_ml_op {
+struct __rte_cache_aligned rte_ml_op {
 	uint16_t model_id;
 	/**< Model ID to be used for the operation. */
 	uint16_t nb_batches;
@@ -469,7 +469,7 @@  struct rte_ml_op {
 	 * dequeue and enqueue operation.
 	 * The application should not modify this field.
-} __rte_cache_aligned;
 /* Enqueue/Dequeue operations */
diff --git a/lib/mldev/rte_mldev_core.h b/lib/mldev/rte_mldev_core.h
index 2279b1d..b3bd281 100644
--- a/lib/mldev/rte_mldev_core.h
+++ b/lib/mldev/rte_mldev_core.h
@@ -626,7 +626,7 @@  struct rte_ml_dev_data {
  * The data structure associated with each ML device.
-struct rte_ml_dev {
+struct __rte_cache_aligned rte_ml_dev {
 	/** Pointer to PMD enqueue function. */
 	mldev_enqueue_t enqueue_burst;
@@ -647,7 +647,7 @@  struct rte_ml_dev {
 	/** Flag indicating the device is attached. */
 	__extension__ uint8_t attached : 1;
-} __rte_cache_aligned;
  * @internal