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-rw-r--r--drivers/misc/altera-stapl/altera-comp.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/misc/altera-stapl/altera-comp.c b/drivers/misc/altera-stapl/altera-comp.c
new file mode 100644
index 000000000000..49b103bedaaf
--- /dev/null
+++ b/drivers/misc/altera-stapl/altera-comp.c
@@ -0,0 +1,142 @@
+/*
+ * altera-comp.c
+ *
+ * altera FPGA driver
+ *
+ * Copyright (C) Altera Corporation 1998-2001
+ * Copyright (C) 2010 NetUP Inc.
+ * Copyright (C) 2010 Igor M. Liplianin <liplianin@netup.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include "altera-exprt.h"
+
+#define SHORT_BITS 16
+#define CHAR_BITS 8
+#define DATA_BLOB_LENGTH 3
+#define MATCH_DATA_LENGTH 8192
+#define ALTERA_REQUEST_SIZE 1024
+#define ALTERA_BUFFER_SIZE (MATCH_DATA_LENGTH + ALTERA_REQUEST_SIZE)
+
+static u32 altera_bits_req(u32 n)
+{
+ u32 result = SHORT_BITS;
+
+ if (n == 0)
+ result = 1;
+ else {
+ /* Look for the highest non-zero bit position */
+ while ((n & (1 << (SHORT_BITS - 1))) == 0) {
+ n <<= 1;
+ --result;
+ }
+ }
+
+ return result;
+}
+
+static u32 altera_read_packed(u8 *buffer, u32 bits, u32 *bits_avail,
+ u32 *in_index)
+{
+ u32 result = 0;
+ u32 shift = 0;
+ u32 databyte = 0;
+
+ while (bits > 0) {
+ databyte = buffer[*in_index];
+ result |= (((databyte >> (CHAR_BITS - *bits_avail))
+ & (0xff >> (CHAR_BITS - *bits_avail))) << shift);
+
+ if (bits <= *bits_avail) {
+ result &= (0xffff >> (SHORT_BITS - (bits + shift)));
+ *bits_avail -= bits;
+ bits = 0;
+ } else {
+ ++(*in_index);
+ shift += *bits_avail;
+ bits -= *bits_avail;
+ *bits_avail = CHAR_BITS;
+ }
+ }
+
+ return result;
+}
+
+u32 altera_shrink(u8 *in, u32 in_length, u8 *out, u32 out_length, s32 version)
+{
+ u32 i, j, data_length = 0L;
+ u32 offset, length;
+ u32 match_data_length = MATCH_DATA_LENGTH;
+ u32 bits_avail = CHAR_BITS;
+ u32 in_index = 0L;
+
+ if (version > 0)
+ --match_data_length;
+
+ for (i = 0; i < out_length; ++i)
+ out[i] = 0;
+
+ /* Read number of bytes in data. */
+ for (i = 0; i < sizeof(in_length); ++i) {
+ data_length = data_length | (
+ altera_read_packed(in,
+ CHAR_BITS,
+ &bits_avail,
+ &in_index) << (i * CHAR_BITS));
+ }
+
+ if (data_length > out_length) {
+ data_length = 0L;
+ return data_length;
+ }
+
+ i = 0;
+ while (i < data_length) {
+ /* A 0 bit indicates literal data. */
+ if (altera_read_packed(in, 1, &bits_avail,
+ &in_index) == 0) {
+ for (j = 0; j < DATA_BLOB_LENGTH; ++j) {
+ if (i < data_length) {
+ out[i] = (u8)altera_read_packed(in,
+ CHAR_BITS,
+ &bits_avail,
+ &in_index);
+ i++;
+ }
+ }
+ } else {
+ /* A 1 bit indicates offset/length to follow. */
+ offset = altera_read_packed(in, altera_bits_req((s16)
+ (i > match_data_length ?
+ match_data_length : i)),
+ &bits_avail,
+ &in_index);
+ length = altera_read_packed(in, CHAR_BITS,
+ &bits_avail,
+ &in_index);
+ for (j = 0; j < length; ++j) {
+ if (i < data_length) {
+ out[i] = out[i - offset];
+ i++;
+ }
+ }
+ }
+ }
+
+ return data_length;
+}

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