The {prepare,unprepare}_crypt_hardware callbacks were added back in 2016
by commit 735d37b5424b ("crypto: engine - Introduce the block request
crypto engine framework"), but they were never implemented by any driver.
Remove them as they are unused.

Since the 'engine->idling' and 'was_busy' flags are no longer needed,
remove them as well.

Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Remove request batching support from crypto_engine, as there are no
drivers using this feature and it doesn't really work that well.

Instead of doing batching based on backlog, a more optimal approach
would be for the user to handle the batching (similar to how IPsec
can hook into GSO to get 64K of data each time or how block encryption
can use unit sizes much greater than 4K).

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Realign struct crypto_engine to reduce its size by 8 bytes. Total size
is now 192 bytes, allowing it to fit within 3 cachelines instead of 4.

pahole output before:

  /* size: 200, cachelines: 4, members: 17 */
  /* sum members: 183, holes: 3, sum holes: 17 */
  /* paddings: 1, sum paddings: 4 */
  /* last cacheline: 8 bytes */

and after:

  /* size: 192, cachelines: 3, members: 17 */
  /* sum members: 183, holes: 2, sum holes: 9 */
  /* paddings: 1, sum paddings: 4 */

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Most drivers should not access the internal details of struct
crypto_engine.  Move it into the internal header file.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Create crypto/internal/engine.h to house details that should not
be used by drivers.  It is empty for the time being.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>