linux/drivers/misc/altera-stapl/altera-comp.c
Thomas Gleixner 74ba9207e1 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 441 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:36:45 +02:00

129 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* 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>
*/
#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;
}