crypto: iaa - use bounce buffer for multi-sg decompress input

Since commit e2c3b6b21c77 ("mm: zswap: use SG list decompression APIs
from zsmalloc"), zswap passes the raw zsmalloc SG list directly to
crypto drivers, so a compressed object spanning multiple pages reaches
IAA as a multi-entry source. Such requests currently fall back to
software decompression.

As IAA hardware requires a single DMA source buffer, linearize small
multi-entry sources into a pre-allocated bounce page and submit that to
the hardware instead of falling back to software. Keep the software
fallback only for multi-entry destinations. This recovers most of the
performance lost by using the software fallback.

Store the bounce-page state in the acomp request context alongside the
existing compression CRC, free it through a shared source-unmap helper,
and back the pages with a small module-wide mempool so the path remains
available in reclaim-driven callers.

Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

0 files changed, 0 insertions, 0 deletions