Eric Lee / linux-smarc-t335x-v3.2

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Commit 5fa0fea27461f5ff7fad07687618db08272e9502

Authored by Herbert Xu
Committed by David S. Miller
1 parent e962a653f3
Exists in master and in 4 other branches v3.2_AM335xPSP_04.06.00.11, v3.2_NEWT335xPSP_04.06.00.11, v3.2_SBC_SMARTMEN, v3.2_SMARCT335xPSP_04.06.00.11

[CRYPTO] scatterwalk: Add scatterwalk_map_and_copy 

This patch adds the function scatterwalk_map_and_copy which reads or
writes a chunk of data from a scatterlist at a given offset.  It will
be used by authenc which would read/write the authentication data at
the end of the cipher/plain text.

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

Showing 2 changed files with 25 additions and 0 deletions Side-by-side Diff

crypto/scatterwalk.c
Diff comments   View file @ 5fa0fea
... ... @@ -107,4 +107,26 @@
107 107 }
108 108 }
109 109 EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
  110 +
  111 +void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
  112 + unsigned int start, unsigned int nbytes, int out)
  113 +{
  114 + struct scatter_walk walk;
  115 + unsigned int offset = 0;
  116 +
  117 + for (;;) {
  118 + scatterwalk_start(&walk, sg);
  119 +
  120 + if (start < offset + sg->length)
  121 + break;
  122 +
  123 + offset += sg->length;
  124 + sg = sg_next(sg);
  125 + }
  126 +
  127 + scatterwalk_advance(&walk, start - offset);
  128 + scatterwalk_copychunks(buf, &walk, nbytes, out);
  129 + scatterwalk_done(&walk, out, 0);
  130 +}
  131 +EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
crypto/scatterwalk.h
Diff comments   View file @ 5fa0fea
... ... @@ -74,5 +74,8 @@
74 74 void *scatterwalk_map(struct scatter_walk *walk, int out);
75 75 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
76 76  
  77 +void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
  78 + unsigned int start, unsigned int nbytes, int out);
  79 +
77 80 #endif /* _CRYPTO_SCATTERWALK_H */