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authorAlexander Graf <agraf@suse.de>2012-10-31 13:36:18 +0100
committerAlexander Graf <agraf@suse.de>2012-10-31 13:36:18 +0100
commit0588000eac9ba4178cebade437da3b28e8fad48f (patch)
tree697e514a0a0193f17a54f372dd18c5cd3927e154 /lib/mpi/mpicoder.c
parent8b5869ad85f703ffeb25e656eab826f6b85b984c (diff)
parent81c52c56e2b43589091ee29038bcf793d3f184ab (diff)
Merge commit 'origin/queue' into for-queue
Conflicts: arch/powerpc/include/asm/Kbuild arch/powerpc/include/uapi/asm/Kbuild
Diffstat (limited to 'lib/mpi/mpicoder.c')
-rw-r--r--lib/mpi/mpicoder.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index f0fa6599580..3962b7f7fe3 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -18,10 +18,65 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
+#include <linux/bitops.h>
+#include <asm-generic/bitops/count_zeros.h>
#include "mpi-internal.h"
#define MAX_EXTERN_MPI_BITS 16384
+/**
+ * mpi_read_raw_data - Read a raw byte stream as a positive integer
+ * @xbuffer: The data to read
+ * @nbytes: The amount of data to read
+ */
+MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes)
+{
+ const uint8_t *buffer = xbuffer;
+ int i, j;
+ unsigned nbits, nlimbs;
+ mpi_limb_t a;
+ MPI val = NULL;
+
+ while (nbytes >= 0 && buffer[0] == 0) {
+ buffer++;
+ nbytes--;
+ }
+
+ nbits = nbytes * 8;
+ if (nbits > MAX_EXTERN_MPI_BITS) {
+ pr_info("MPI: mpi too large (%u bits)\n", nbits);
+ return NULL;
+ }
+ if (nbytes > 0)
+ nbits -= count_leading_zeros(buffer[0]);
+ else
+ nbits = 0;
+
+ nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ val = mpi_alloc(nlimbs);
+ if (!val)
+ return NULL;
+ val->nbits = nbits;
+ val->sign = 0;
+ val->nlimbs = nlimbs;
+
+ if (nbytes > 0) {
+ i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
+ i %= BYTES_PER_MPI_LIMB;
+ for (j = nlimbs; j > 0; j--) {
+ a = 0;
+ for (; i < BYTES_PER_MPI_LIMB; i++) {
+ a <<= 8;
+ a |= *buffer++;
+ }
+ i = 0;
+ val->d[j - 1] = a;
+ }
+ }
+ return val;
+}
+EXPORT_SYMBOL_GPL(mpi_read_raw_data);
+
MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
{
const uint8_t *buffer = xbuffer;