cregit-Linux how code gets into the kernel

Release 4.7 drivers/misc/altera-stapl/altera-comp.c

/*
 * 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; }

Contributors

PersonTokensPropCommitsCommitProp
igor m. liplianinigor m. liplianin58100.00%1100.00%
Total58100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
igor m. liplianinigor m. liplianin143100.00%1100.00%
Total143100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
igor m. liplianinigor m. liplianin307100.00%1100.00%
Total307100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
igor m. liplianinigor m. liplianin539100.00%1100.00%
Total539100.00%1100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}