From: Eric Biggers Date: Wed, 19 Feb 2025 18:23:27 +0000 (-0800) Subject: crypto: scatterwalk - add scatterwalk_get_sglist() X-Git-Tag: v6.15-rc1~118^2~110 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=84b1576355c41a935102da5d62bb28e74be3db45;p=thirdparty%2Flinux.git crypto: scatterwalk - add scatterwalk_get_sglist() Add a function that creates a scatterlist that represents the remaining data in a walk. This will be used to replace chain_to_walk() in net/tls/tls_device_fallback.c so that it will no longer need to reach into the internals of struct scatter_walk. Cc: Boris Pismenny Cc: Jakub Kicinski Cc: John Fastabend Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h index 1689ecd7ddafa..f6262d05a3c75 100644 --- a/include/crypto/scatterwalk.h +++ b/include/crypto/scatterwalk.h @@ -69,6 +69,23 @@ static inline struct page *scatterwalk_page(struct scatter_walk *walk) return sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT); } +/* + * Create a scatterlist that represents the remaining data in a walk. Uses + * chaining to reference the original scatterlist, so this uses at most two + * entries in @sg_out regardless of the number of entries in the original list. + * Assumes that sg_init_table() was already done. + */ +static inline void scatterwalk_get_sglist(struct scatter_walk *walk, + struct scatterlist sg_out[2]) +{ + if (walk->offset >= walk->sg->offset + walk->sg->length) + scatterwalk_start(walk, sg_next(walk->sg)); + sg_set_page(sg_out, sg_page(walk->sg), + walk->sg->offset + walk->sg->length - walk->offset, + walk->offset); + scatterwalk_crypto_chain(sg_out, sg_next(walk->sg), 2); +} + static inline void scatterwalk_unmap(void *vaddr) { kunmap_local(vaddr);