 cff4fa8415
			
		
	
	
	cff4fa8415
	
	
	
		
			
			[mchehab@redhat.com: Fix a merge conflict] Signed-off-by: Igor M. Liplianin <liplianin@netup.ru> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
		
			
				
	
	
		
			142 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			142 lines
		
	
	
	
		
			3.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * altera-comp.c
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|  *
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|  * altera FPGA driver
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|  *
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|  * Copyright (C) Altera Corporation 1998-2001
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|  * Copyright (C) 2010 NetUP Inc.
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|  * Copyright (C) 2010 Igor M. Liplianin <liplianin@netup.ru>
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  *
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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|  */
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| 
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| #include <linux/kernel.h>
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| #include "altera-exprt.h"
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| 
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| #define	SHORT_BITS		16
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| #define	CHAR_BITS		8
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| #define	DATA_BLOB_LENGTH	3
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| #define	MATCH_DATA_LENGTH	8192
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| #define ALTERA_REQUEST_SIZE	1024
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| #define ALTERA_BUFFER_SIZE	(MATCH_DATA_LENGTH + ALTERA_REQUEST_SIZE)
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| 
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| static u32 altera_bits_req(u32 n)
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| {
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| 	u32 result = SHORT_BITS;
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| 
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| 	if (n == 0)
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| 		result = 1;
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| 	else {
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| 		/* Look for the highest non-zero bit position */
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| 		while ((n & (1 << (SHORT_BITS - 1))) == 0) {
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| 			n <<= 1;
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| 			--result;
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| 		}
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| 	}
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| 
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| 	return result;
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| }
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| 
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| static u32 altera_read_packed(u8 *buffer, u32 bits, u32 *bits_avail,
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| 							u32 *in_index)
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| {
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| 	u32 result = 0;
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| 	u32 shift = 0;
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| 	u32 databyte = 0;
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| 
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| 	while (bits > 0) {
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| 		databyte = buffer[*in_index];
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| 		result |= (((databyte >> (CHAR_BITS - *bits_avail))
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| 			& (0xff >> (CHAR_BITS - *bits_avail))) << shift);
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| 
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| 		if (bits <= *bits_avail) {
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| 			result &= (0xffff >> (SHORT_BITS - (bits + shift)));
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| 			*bits_avail -= bits;
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| 			bits = 0;
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| 		} else {
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| 			++(*in_index);
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| 			shift += *bits_avail;
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| 			bits -= *bits_avail;
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| 			*bits_avail = CHAR_BITS;
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| 		}
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| 	}
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| 
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| 	return result;
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| }
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| 
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| u32 altera_shrink(u8 *in, u32 in_length, u8 *out, u32 out_length, s32 version)
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| {
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| 	u32 i, j, data_length = 0L;
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| 	u32 offset, length;
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| 	u32 match_data_length = MATCH_DATA_LENGTH;
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| 	u32 bits_avail = CHAR_BITS;
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| 	u32 in_index = 0L;
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| 
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| 	if (version > 0)
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| 		--match_data_length;
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| 
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| 	for (i = 0; i < out_length; ++i)
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| 		out[i] = 0;
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| 
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| 	/* Read number of bytes in data. */
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| 	for (i = 0; i < sizeof(in_length); ++i) {
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| 		data_length = data_length | (
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| 			altera_read_packed(in,
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| 					CHAR_BITS,
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| 					&bits_avail,
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| 					&in_index) << (i * CHAR_BITS));
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| 	}
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| 
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| 	if (data_length > out_length) {
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| 		data_length = 0L;
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| 		return data_length;
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| 	}
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| 
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| 	i = 0;
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| 	while (i < data_length) {
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| 		/* A 0 bit indicates literal data. */
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| 		if (altera_read_packed(in, 1, &bits_avail,
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| 						&in_index) == 0) {
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| 			for (j = 0; j < DATA_BLOB_LENGTH; ++j) {
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| 				if (i < data_length) {
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| 					out[i] = (u8)altera_read_packed(in,
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| 							CHAR_BITS,
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| 							&bits_avail,
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| 							&in_index);
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| 					i++;
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| 				}
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| 			}
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| 		} else {
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| 			/* A 1 bit indicates offset/length to follow. */
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| 			offset = altera_read_packed(in, altera_bits_req((s16)
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| 					(i > match_data_length ?
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| 						match_data_length : i)),
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| 					&bits_avail,
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| 					&in_index);
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| 			length = altera_read_packed(in, CHAR_BITS,
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| 					&bits_avail,
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| 					&in_index);
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| 			for (j = 0; j < length; ++j) {
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| 				if (i < data_length) {
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| 					out[i] = out[i - offset];
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| 					i++;
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| 				}
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| 			}
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| 		}
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| 	}
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| 
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| 	return data_length;
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| }
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