-#include "scatterwalk.h"
-
-static inline void xor_64(u8 *a, const u8 *b)
-{
- ((u32 *)a)[0] ^= ((u32 *)b)[0];
- ((u32 *)a)[1] ^= ((u32 *)b)[1];
-}
-
-static inline void xor_128(u8 *a, const u8 *b)
-{
- ((u32 *)a)[0] ^= ((u32 *)b)[0];
- ((u32 *)a)[1] ^= ((u32 *)b)[1];
- ((u32 *)a)[2] ^= ((u32 *)b)[2];
- ((u32 *)a)[3] ^= ((u32 *)b)[3];
-}
-
-static unsigned int crypt_slow(const struct cipher_desc *desc,
- struct scatter_walk *in,
- struct scatter_walk *out, unsigned int bsize)
-{
- unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);
- u8 buffer[bsize * 2 + alignmask];
- u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
- u8 *dst = src + bsize;
- unsigned int n;
-
- n = scatterwalk_copychunks(src, in, bsize, 0);
- scatterwalk_advance(in, n);
-
- desc->prfn(desc, dst, src, bsize);
-
- n = scatterwalk_copychunks(dst, out, bsize, 1);
- scatterwalk_advance(out, n);
-
- return bsize;
-}
-
-static inline unsigned int crypt_fast(const struct cipher_desc *desc,
- struct scatter_walk *in,
- struct scatter_walk *out,
- unsigned int nbytes, u8 *tmp)
-{
- u8 *src, *dst;
-
- src = in->data;
- dst = scatterwalk_samebuf(in, out) ? src : out->data;
-
- if (tmp) {
- memcpy(tmp, in->data, nbytes);
- src = tmp;
- dst = tmp;
- }
-
- nbytes = desc->prfn(desc, dst, src, nbytes);
-
- if (tmp)
- memcpy(out->data, tmp, nbytes);
-
- scatterwalk_advance(in, nbytes);
- scatterwalk_advance(out, nbytes);
-
- return nbytes;
-}
-
-/*
- * Generic encrypt/decrypt wrapper for ciphers, handles operations across
- * multiple page boundaries by using temporary blocks. In user context,
- * the kernel is given a chance to schedule us once per page.
- */
-static int crypt(const struct cipher_desc *desc,
- struct scatterlist *dst,
- struct scatterlist *src,
- unsigned int nbytes)
-{
- struct scatter_walk walk_in, walk_out;
- struct crypto_tfm *tfm = desc->tfm;
- const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
- unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
- unsigned long buffer = 0;
-
- if (!nbytes)
- return 0;
-
- if (nbytes % bsize) {
- tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
- return -EINVAL;
- }
-
- scatterwalk_start(&walk_in, src);
- scatterwalk_start(&walk_out, dst);
-
- for(;;) {
- unsigned int n = nbytes;
- u8 *tmp = NULL;
-
- if (!scatterwalk_aligned(&walk_in, alignmask) ||
- !scatterwalk_aligned(&walk_out, alignmask)) {
- if (!buffer) {
- buffer = __get_free_page(GFP_ATOMIC);
- if (!buffer)
- n = 0;
- }
- tmp = (u8 *)buffer;
- }
-
- scatterwalk_map(&walk_in, 0);
- scatterwalk_map(&walk_out, 1);
-
- n = scatterwalk_clamp(&walk_in, n);
- n = scatterwalk_clamp(&walk_out, n);
-
- if (likely(n >= bsize))
- n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);
- else
- n = crypt_slow(desc, &walk_in, &walk_out, bsize);
-
- nbytes -= n;
-
- scatterwalk_done(&walk_in, 0, nbytes);
- scatterwalk_done(&walk_out, 1, nbytes);
-
- if (!nbytes)
- break;
-
- crypto_yield(tfm);
- }
-
- if (buffer)
- free_page(buffer);
-
- return 0;
-}