1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * altera-comp.c
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * altera FPGA driver
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Copyright (C) Altera Corporation 1998-2001
8*4882a593Smuzhiyun * Copyright (C) 2010 NetUP Inc.
9*4882a593Smuzhiyun * Copyright (C) 2010 Igor M. Liplianin <liplianin@netup.ru>
10*4882a593Smuzhiyun */
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun #include <linux/kernel.h>
13*4882a593Smuzhiyun #include "altera-exprt.h"
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #define SHORT_BITS 16
16*4882a593Smuzhiyun #define CHAR_BITS 8
17*4882a593Smuzhiyun #define DATA_BLOB_LENGTH 3
18*4882a593Smuzhiyun #define MATCH_DATA_LENGTH 8192
19*4882a593Smuzhiyun #define ALTERA_REQUEST_SIZE 1024
20*4882a593Smuzhiyun #define ALTERA_BUFFER_SIZE (MATCH_DATA_LENGTH + ALTERA_REQUEST_SIZE)
21*4882a593Smuzhiyun
altera_bits_req(u32 n)22*4882a593Smuzhiyun static u32 altera_bits_req(u32 n)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun u32 result = SHORT_BITS;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun if (n == 0)
27*4882a593Smuzhiyun result = 1;
28*4882a593Smuzhiyun else {
29*4882a593Smuzhiyun /* Look for the highest non-zero bit position */
30*4882a593Smuzhiyun while ((n & (1 << (SHORT_BITS - 1))) == 0) {
31*4882a593Smuzhiyun n <<= 1;
32*4882a593Smuzhiyun --result;
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun return result;
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun
altera_read_packed(u8 * buffer,u32 bits,u32 * bits_avail,u32 * in_index)39*4882a593Smuzhiyun static u32 altera_read_packed(u8 *buffer, u32 bits, u32 *bits_avail,
40*4882a593Smuzhiyun u32 *in_index)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun u32 result = 0;
43*4882a593Smuzhiyun u32 shift = 0;
44*4882a593Smuzhiyun u32 databyte = 0;
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun while (bits > 0) {
47*4882a593Smuzhiyun databyte = buffer[*in_index];
48*4882a593Smuzhiyun result |= (((databyte >> (CHAR_BITS - *bits_avail))
49*4882a593Smuzhiyun & (0xff >> (CHAR_BITS - *bits_avail))) << shift);
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun if (bits <= *bits_avail) {
52*4882a593Smuzhiyun result &= (0xffff >> (SHORT_BITS - (bits + shift)));
53*4882a593Smuzhiyun *bits_avail -= bits;
54*4882a593Smuzhiyun bits = 0;
55*4882a593Smuzhiyun } else {
56*4882a593Smuzhiyun ++(*in_index);
57*4882a593Smuzhiyun shift += *bits_avail;
58*4882a593Smuzhiyun bits -= *bits_avail;
59*4882a593Smuzhiyun *bits_avail = CHAR_BITS;
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun return result;
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
altera_shrink(u8 * in,u32 in_length,u8 * out,u32 out_length,s32 version)66*4882a593Smuzhiyun u32 altera_shrink(u8 *in, u32 in_length, u8 *out, u32 out_length, s32 version)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun u32 i, j, data_length = 0L;
69*4882a593Smuzhiyun u32 offset, length;
70*4882a593Smuzhiyun u32 match_data_length = MATCH_DATA_LENGTH;
71*4882a593Smuzhiyun u32 bits_avail = CHAR_BITS;
72*4882a593Smuzhiyun u32 in_index = 0L;
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun if (version > 0)
75*4882a593Smuzhiyun --match_data_length;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun for (i = 0; i < out_length; ++i)
78*4882a593Smuzhiyun out[i] = 0;
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun /* Read number of bytes in data. */
81*4882a593Smuzhiyun for (i = 0; i < sizeof(in_length); ++i) {
82*4882a593Smuzhiyun data_length = data_length | (
83*4882a593Smuzhiyun altera_read_packed(in,
84*4882a593Smuzhiyun CHAR_BITS,
85*4882a593Smuzhiyun &bits_avail,
86*4882a593Smuzhiyun &in_index) << (i * CHAR_BITS));
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun
89*4882a593Smuzhiyun if (data_length > out_length) {
90*4882a593Smuzhiyun data_length = 0L;
91*4882a593Smuzhiyun return data_length;
92*4882a593Smuzhiyun }
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun i = 0;
95*4882a593Smuzhiyun while (i < data_length) {
96*4882a593Smuzhiyun /* A 0 bit indicates literal data. */
97*4882a593Smuzhiyun if (altera_read_packed(in, 1, &bits_avail,
98*4882a593Smuzhiyun &in_index) == 0) {
99*4882a593Smuzhiyun for (j = 0; j < DATA_BLOB_LENGTH; ++j) {
100*4882a593Smuzhiyun if (i < data_length) {
101*4882a593Smuzhiyun out[i] = (u8)altera_read_packed(in,
102*4882a593Smuzhiyun CHAR_BITS,
103*4882a593Smuzhiyun &bits_avail,
104*4882a593Smuzhiyun &in_index);
105*4882a593Smuzhiyun i++;
106*4882a593Smuzhiyun }
107*4882a593Smuzhiyun }
108*4882a593Smuzhiyun } else {
109*4882a593Smuzhiyun /* A 1 bit indicates offset/length to follow. */
110*4882a593Smuzhiyun offset = altera_read_packed(in, altera_bits_req((s16)
111*4882a593Smuzhiyun (i > match_data_length ?
112*4882a593Smuzhiyun match_data_length : i)),
113*4882a593Smuzhiyun &bits_avail,
114*4882a593Smuzhiyun &in_index);
115*4882a593Smuzhiyun length = altera_read_packed(in, CHAR_BITS,
116*4882a593Smuzhiyun &bits_avail,
117*4882a593Smuzhiyun &in_index);
118*4882a593Smuzhiyun for (j = 0; j < length; ++j) {
119*4882a593Smuzhiyun if (i < data_length) {
120*4882a593Smuzhiyun out[i] = out[i - offset];
121*4882a593Smuzhiyun i++;
122*4882a593Smuzhiyun }
123*4882a593Smuzhiyun }
124*4882a593Smuzhiyun }
125*4882a593Smuzhiyun }
126*4882a593Smuzhiyun
127*4882a593Smuzhiyun return data_length;
128*4882a593Smuzhiyun }
129