ch_ktls: Use memcpy_from_page() instead of k[un]map_atomic()
authorAnirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Wed, 23 Nov 2022 20:52:14 +0000 (12:52 -0800)
committerDavid S. Miller <davem@davemloft.net>
Fri, 25 Nov 2022 10:44:00 +0000 (10:44 +0000)
commit51337ef07a40652efec48bb4103880c39ad0f119
tree57f728c3c54abf7081d2f1693cd46f2d4d12d2e2
parent8781994a5ebef7ea06a6f6f54390fd747e8d97f1
ch_ktls: Use memcpy_from_page() instead of k[un]map_atomic()

kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace
the map-memcpy-unmap usage pattern (done using k[un]map_atomic()) with
memcpy_from_page(), which internally uses kmap_local_page() and
kunmap_local(). This renders the variables 'data' and 'vaddr' unnecessary,
and so remove these too.

Note that kmap_atomic() disables preemption and page-fault processing, but
kmap_local_page() doesn't. When converting uses of kmap_atomic(), one has
to check if the code being executed between the map/unmap implicitly
depends on page-faults and/or preemption being disabled. If yes, then code
to disable page-faults and/or preemption should also be added for
functional correctness. That however doesn't appear to be the case here,
so just memcpy_from_page() is used.

Also note that the page being mapped is not allocated by the driver, and so
the driver doesn't know if the page is in normal memory. This is the reason
kmap_local_page() is used (via memcpy_from_page()) as opposed to
page_address().

I don't have hardware, so this change has only been compile tested.

Cc: Ayush Sawal <ayush.sawal@chelsio.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Acked-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c