patch-2.4.19 linux-2.4.19/drivers/net/wan/8253x/crc32.c

• Lines: 149
• Date: Fri Aug 2 17:39:44 2002
• Orig file: linux-2.4.18/drivers/net/wan/8253x/crc32.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/drivers/net/wan/8253x/crc32.c linux-2.4.19/drivers/net/wan/8253x/crc32.c
@@ -0,0 +1,148 @@
+/* -*- linux-c -*- */
+/******************************************************************************
+ *  FILE:      crc32.c
+ *
+ *  Copyright: Telford Tools, Inc.
+ *             1996
+ *
+ * Copyright (C) 2001 By Joachim Martillo, Telford Tools, Inc.
+ *
+ * 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.
+ *
+ ******************************************************************************
+ */
+/******************************************************************************
+ *  REVISION HISTORY: (Most Recent First)
+ *  -------------------------------------
+ *  2-Apr-91    ALEX    Introduced "fn_calc_novram_crc32()".
+ ******************************************************************************
+ */
+
+/****************************************************/
+/*		    header files		    */
+/****************************************************/
+
+#include "crc32dcl.h"
+#include "endian.h"
+
+/****************************************************/
+/*		    constants			    */
+/****************************************************/
+
+#define k_poly		    ((unsigned int)(0xedb88320))
+#define k_crc_table_size    (256)
+
+#if defined (AMD29K)
+pragma Code ("rkernel");
+pragma Off(cross_jump);
+#endif
+
+/****************************************************/
+/*			static data		    */
+/****************************************************/
+
+#if defined(AMD29K)
+pragma Data (Export,"fastbss");
+#endif defined(AMD29K)
+
+unsigned int gg_a_crc_table[k_crc_table_size];
+
+#if defined(AMD29K)
+pragma Data;
+#endif defined(AMD29K)
+
+
+/****************************************************/
+/*		    global procedures		    */
+/****************************************************/
+
+void
+fn_init_crc_table()
+{
+	short	i_table;
+	
+	for (i_table = 0; i_table < k_crc_table_size; i_table++)
+	{
+		unsigned int	result = 0;
+		short	i_bit;
+		
+		for (i_bit = 0; i_bit < 8; i_bit++)
+		{
+			unsigned int    bit = ((i_table  & (1 << i_bit)) != 0);
+			
+			if ((bit ^ (result & 1)) != 0)
+				result = (result >> 1) ^ k_poly;
+			else
+				result >>= 1;
+		}
+		
+		gg_a_crc_table[i_table] = result;
+	}
+	
+} /* end of fn_init_crc_table */
+
+/****************************************************/
+
+static unsigned int
+fn_calc_memory_chunk_crc32(void *p, unsigned int n_bytes, unsigned int crc)
+{
+	unsigned char    *p_uc   = (unsigned char*)p;
+	unsigned int   result  = ~crc;
+	
+	while (n_bytes-- > 0)
+	{
+		result = (result >> 8) ^ gg_a_crc_table[(result ^ *p_uc++) & 0xff];
+	}
+	
+	return(~result);
+	
+} /* end of fn_calc_memory_chunk_crc32 */
+
+/****************************************************/
+
+unsigned int
+fn_calc_memory_crc32(void *p, unsigned int n_bytes)
+{
+	fnm_assert_stmt(n_bytes > 4);
+	
+	return(fn_calc_memory_chunk_crc32(p, n_bytes, k_initial_crc_value));
+	
+} /* end of fn_calc_memory_crc32 */
+
+/****************************************************/
+
+unsigned int
+fn_check_memory_crc32(void *p, unsigned int n_bytes, unsigned int crc)
+{
+	return(fn_calc_memory_crc32(p, n_bytes) == crc);
+	
+} /* end of fn_check_memory_crc32 */
+
+
+/****************************************************/
+/* Adds current longword to the crc value and       */
+/* returns that value.                              */
+unsigned int
+fn_update_crc(char *val, unsigned int crcval)
+{
+	long i;
+	
+	/* ----< break long into bytes >---- */
+	/* ----< put bytes into crc >---- */
+	for (i = 0; i < 4; i++)
+	{
+		crcval = gg_a_crc_table[(crcval ^ val[i]) & 0xff] ^
+			((crcval >> 8) & 0x00ffffff);
+	}
+	return(crcval);
+}					/* endfunc--fn_update_crc */
+
+
+/****************************************************/
+/****************************************************/
+/*	    End source file "crc32.c"		    */
+/****************************************************/
+/****************************************************/