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RE: CVS jffs2 does not compile with stock 2.4.19



Hi

MTD CVS depends on the new CRC32 stuff in 2.5. Here is a patch that worked for
me.

  Jocke

> 
> 
> Hi guys, I'm trying to get 2.4.19 to compile with the jffs2 code in the
> CVS, but am encountering problems.
> 
> -jf
> 
--- old/include/linux/crc32.h	Wed Sep 25 16:46:43 2002
+++ new/include/linux/crc32.h	Thu Sep 26 18:15:45 2002
@@ -1,49 +1,17 @@
 /*
- * crc32.h for early Linux 2.4.19pre kernel inclusion
- * This defines ether_crc_le() and ether_crc() as inline functions
- * This is slated to change to using the library crc32 functions
- * as kernel 2.5.2 included at some future date.
+ * crc32.h
+ * See linux/lib/crc32.c for license and changes
  */
 #ifndef _LINUX_CRC32_H
 #define _LINUX_CRC32_H
 
 #include <linux/types.h>
 
-/* The little-endian AUTODIN II ethernet CRC calculation.
-   N.B. Do not use for bulk data, use a table-based routine instead.
-   This is common code and should be moved to net/core/crc.c */
-static unsigned const ethernet_polynomial_le = 0xedb88320U;
-static inline unsigned ether_crc_le(int length, unsigned char *data)
-{
-	unsigned int crc = 0xffffffff;	/* Initial value. */
-	while(--length >= 0) {
-		unsigned char current_octet = *data++;
-		int bit;
-		for (bit = 8; --bit >= 0; current_octet >>= 1) {
-			if ((crc ^ current_octet) & 1) {
-				crc >>= 1;
-				crc ^= ethernet_polynomial_le;
-			} else
-				crc >>= 1;
-		}
-	}
-	return crc;
-}
+extern u32  crc32_le(u32 crc, unsigned char const *p, size_t len);
+extern u32  crc32_be(u32 crc, unsigned char const *p, size_t len);
 
-static unsigned const ethernet_polynomial = 0x04c11db7U;
-static inline u32 ether_crc(int length, unsigned char *data)
-{
-	int crc = -1;
-	while (--length >= 0) {
-		unsigned char current_octet = *data++;
-		int bit;
-		for (bit = 0; bit < 8; bit++, current_octet >>= 1) {
-			crc = (crc << 1) ^
-				((crc < 0) ^ (current_octet & 1) ?
-				 ethernet_polynomial : 0);
-		}
-	}
-	return crc;
-}
+#define crc32(seed, data, length)  crc32_le(seed, (unsigned char const *)data, length)
+#define ether_crc_le(length, data) crc32_le(~0, data, length)
+#define ether_crc(length, data)    crc32_be(~0, data, length)
 
 #endif /* _LINUX_CRC32_H */
--- old/lib/Makefile	Thu Sep 26 18:16:39 2002
+++ new/lib/Makefile	Fri Oct 11 12:08:12 2002
@@ -20,9 +20,15 @@
   obj-y += dec_and_lock.o
 endif
 
+obj-$(CONFIG_CRC32)     += crc32.o
+
 subdir-$(CONFIG_ZLIB_INFLATE) += zlib_inflate
 subdir-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate
 
+include $(TOPDIR)/drivers/net/Makefile.lib
+include $(TOPDIR)/drivers/usb/Makefile.lib
+include $(TOPDIR)/fs/Makefile.lib
+
 # Include the subdirs, if necessary.
 obj-y += $(join $(subdir-y),$(subdir-y:%=/%.o))
 
--- old/dev/null	Thu Aug 30 22:30:55 2001
+++ new/lib/crc32.c	Thu Sep 26 18:16:25 2002
@@ -0,0 +1,571 @@
+/* 
+ * Oct 15, 2000 Matt Domsch <Matt_Domsch@xxxxxxx.com>
+ * Nicer crc32 functions/docs submitted by linux@xxxxxxx.  Thanks!
+ *
+ * Oct 12, 2000 Matt Domsch <Matt_Domsch@xxxxxxx.com>
+ * Same crc32 function was used in 5 other places in the kernel.
+ * I made one version, and deleted the others.
+ * There are various incantations of crc32().  Some use a seed of 0 or ~0.
+ * Some xor at the end with ~0.  The generic crc32() function takes
+ * seed as an argument, and doesn't xor at the end.  Then individual
+ * users can do whatever they need.
+ *   drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
+ *   fs/jffs2 uses seed 0, doesn't xor with ~0.
+ *   fs/partitions/efi.c uses seed ~0, xor's with ~0.
+ * 
+ */
+
+#include <linux/crc32.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+
+#if __GNUC__ >= 3	/* 2.x has "attribute", but only 3.0 has "pure */
+#define attribute(x) __attribute__(x)
+#else
+#define attribute(x)
+#endif
+
+/*
+ * This code is in the public domain; copyright abandoned.
+ * Liability for non-performance of this code is limited to the amount
+ * you paid for it.  Since it is distributed for free, your refund will
+ * be very very small.  If it breaks, you get to keep both pieces.
+ */
+
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@xxxxxxx.com>");
+MODULE_DESCRIPTION("Ethernet CRC32 calculations");
+MODULE_LICENSE("GPL and additional rights");
+
+
+/*
+ * There are multiple 16-bit CRC polynomials in common use, but this is
+ * *the* standard CRC-32 polynomial, first popularized by Ethernet.
+ * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0
+ */
+#define CRCPOLY_LE 0xedb88320
+#define CRCPOLY_BE 0x04c11db7
+
+/* How many bits at a time to use.  Requires a table of 4<<CRC_xx_BITS bytes. */
+/* For less performance-sensitive, use 4 */
+#define CRC_LE_BITS 8
+#define CRC_BE_BITS 8
+
+/*
+ * Little-endian CRC computation.  Used with serial bit streams sent
+ * lsbit-first.  Be sure to use cpu_to_le32() to append the computed CRC.
+ */
+#if CRC_LE_BITS > 8 || CRC_LE_BITS < 1 || CRC_LE_BITS & CRC_LE_BITS-1
+# error CRC_LE_BITS must be a power of 2 between 1 and 8
+#endif
+
+#if CRC_LE_BITS == 1
+/*
+ * In fact, the table-based code will work in this case, but it can be
+ * simplified by inlining the table in ?: form.
+ */
+#define crc32init_le()
+#define crc32cleanup_le()
+/**
+ * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
+ * @xxxxxxx.  ~0 for Ethernet, sometimes 0 for
+ *        other uses, or the previous crc32 value if computing incrementally.
+ * @p   - pointer to buffer over which CRC is run
+ * @len - length of buffer @p
+ * 
+ */
+u32 attribute((pure)) crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++;
+		for (i = 0; i < 8; i++)
+			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
+	}
+	return crc;
+}
+#else				/* Table-based approach */
+
+static u32 *crc32table_le;
+/**
+ * crc32init_le() - allocate and initialize LE table data
+ *
+ * crc is the crc of the byte i; other entries are filled in based on the
+ * fact that crctable[i^j] = crctable[i] ^ crctable[j].
+ *
+ */
+static int __init crc32init_le(void)
+{
+	unsigned i, j;
+	u32 crc = 1;
+
+	crc32table_le =
+	    kmalloc((1 << CRC_LE_BITS) * sizeof(u32), GFP_KERNEL);
+	if (!crc32table_le)
+		return 1;
+	crc32table_le[0] = 0;
+
+	for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) {
+		crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
+		for (j = 0; j < 1 << CRC_LE_BITS; j += 2 * i)
+			crc32table_le[i + j] = crc ^ crc32table_le[j];
+	}
+	return 0;
+}
+
+/**
+ * crc32cleanup_le(): free LE table data
+ */
+static void __exit crc32cleanup_le(void)
+{
+	if (crc32table_le) kfree(crc32table_le);
+	crc32table_le = NULL;
+}
+
+/**
+ * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
+ * @xxxxxxx.  ~0 for Ethernet, sometimes 0 for
+ *        other uses, or the previous crc32 value if computing incrementally.
+ * @p   - pointer to buffer over which CRC is run
+ * @len - length of buffer @p
+ * 
+ */
+u32 attribute((pure)) crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+	while (len--) {
+# if CRC_LE_BITS == 8
+		crc = (crc >> 8) ^ crc32table_le[(crc ^ *p++) & 255];
+# elif CRC_LE_BITS == 4
+		crc ^= *p++;
+		crc = (crc >> 4) ^ crc32table_le[crc & 15];
+		crc = (crc >> 4) ^ crc32table_le[crc & 15];
+# elif CRC_LE_BITS == 2
+		crc ^= *p++;
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+		crc = (crc >> 2) ^ crc32table_le[crc & 3];
+# endif
+	}
+	return crc;
+}
+#endif
+
+/*
+ * Big-endian CRC computation.  Used with serial bit streams sent
+ * msbit-first.  Be sure to use cpu_to_be32() to append the computed CRC.
+ */
+#if CRC_BE_BITS > 8 || CRC_BE_BITS < 1 || CRC_BE_BITS & CRC_BE_BITS-1
+# error CRC_BE_BITS must be a power of 2 between 1 and 8
+#endif
+
+#if CRC_BE_BITS == 1
+/*
+ * In fact, the table-based code will work in this case, but it can be
+ * simplified by inlining the table in ?: form.
+ */
+#define crc32init_be()
+#define crc32cleanup_be()
+
+/**
+ * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
+ * @xxxxxxx.  ~0 for Ethernet, sometimes 0 for
+ *        other uses, or the previous crc32 value if computing incrementally.
+ * @p   - pointer to buffer over which CRC is run
+ * @len - length of buffer @p
+ * 
+ */
+u32 attribute((pure)) crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++ << 24;
+		for (i = 0; i < 8; i++)
+			crc =
+			    (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
+					  0);
+	}
+	return crc;
+}
+
+#else				/* Table-based approach */
+static u32 *crc32table_be;
+
+/**
+ * crc32init_be() - allocate and initialize BE table data
+ */
+static int __init crc32init_be(void)
+{
+	unsigned i, j;
+	u32 crc = 0x80000000;
+
+	crc32table_be =
+	    kmalloc((1 << CRC_BE_BITS) * sizeof(u32), GFP_KERNEL);
+	if (!crc32table_be)
+		return 1;
+	crc32table_be[0] = 0;
+
+	for (i = 1; i < 1 << CRC_BE_BITS; i <<= 1) {
+		crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0);
+		for (j = 0; j < i; j++)
+			crc32table_be[i + j] = crc ^ crc32table_be[j];
+	}
+	return 0;
+}
+
+/**
+ * crc32cleanup_be(): free BE table data
+ */
+static void __exit crc32cleanup_be(void)
+{
+	if (crc32table_be) kfree(crc32table_be);
+	crc32table_be = NULL;
+}
+
+
+/**
+ * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
+ * @xxxxxxx.  ~0 for Ethernet, sometimes 0 for
+ *        other uses, or the previous crc32 value if computing incrementally.
+ * @p   - pointer to buffer over which CRC is run
+ * @len - length of buffer @p
+ * 
+ */
+u32 attribute((pure)) crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+	while (len--) {
+# if CRC_BE_BITS == 8
+		crc = (crc << 8) ^ crc32table_be[(crc >> 24) ^ *p++];
+# elif CRC_BE_BITS == 4
+		crc ^= *p++ << 24;
+		crc = (crc << 4) ^ crc32table_be[crc >> 28];
+		crc = (crc << 4) ^ crc32table_be[crc >> 28];
+# elif CRC_BE_BITS == 2
+		crc ^= *p++ << 24;
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+		crc = (crc << 2) ^ crc32table_be[crc >> 30];
+# endif
+	}
+	return crc;
+}
+#endif
+
+/*
+ * A brief CRC tutorial.
+ *
+ * A CRC is a long-division remainder.  You add the CRC to the message,
+ * and the whole thing (message+CRC) is a multiple of the given
+ * CRC polynomial.  To check the CRC, you can either check that the
+ * CRC matches the recomputed value, *or* you can check that the
+ * remainder computed on the message+CRC is 0.  This latter approach
+ * is used by a lot of hardware implementations, and is why so many
+ * protocols put the end-of-frame flag after the CRC.
+ *
+ * It's actually the same long division you learned in school, except that
+ * - We're working in binary, so the digits are only 0 and 1, and
+ * - When dividing polynomials, there are no carries.  Rather than add and
+ *   subtract, we just xor.  Thus, we tend to get a bit sloppy about
+ *   the difference between adding and subtracting.
+ *
+ * A 32-bit CRC polynomial is actually 33 bits long.  But since it's
+ * 33 bits long, bit 32 is always going to be set, so usually the CRC
+ * is written in hex with the most significant bit omitted.  (If you're
+ * familiar with the IEEE 754 floating-point format, it's the same idea.)
+ *
+ * Note that a CRC is computed over a string of *bits*, so you have
+ * to decide on the endianness of the bits within each byte.  To get
+ * the best error-detecting properties, this should correspond to the
+ * order they're actually sent.  For example, standard RS-232 serial is
+ * little-endian; the most significant bit (sometimes used for parity)
+ * is sent last.  And when appending a CRC word to a message, you should
+ * do it in the right order, matching the endianness.
+ *
+ * Just like with ordinary division, the remainder is always smaller than
+ * the divisor (the CRC polynomial) you're dividing by.  Each step of the
+ * division, you take one more digit (bit) of the dividend and append it
+ * to the current remainder.  Then you figure out the appropriate multiple
+ * of the divisor to subtract to being the remainder back into range.
+ * In binary, it's easy - it has to be either 0 or 1, and to make the
+ * XOR cancel, it's just a copy of bit 32 of the remainder.
+ *
+ * When computing a CRC, we don't care about the quotient, so we can
+ * throw the quotient bit away, but subtract the appropriate multiple of
+ * the polynomial from the remainder and we're back to where we started,
+ * ready to process the next bit.
+ *
+ * A big-endian CRC written this way would be coded like:
+ * for (i = 0; i < input_bits; i++) {
+ * 	multiple = remainder & 0x80000000 ? CRCPOLY : 0;
+ * 	remainder = (remainder << 1 | next_input_bit()) ^ multiple;
+ * }
+ * Notice how, to get at bit 32 of the shifted remainder, we look
+ * at bit 31 of the remainder *before* shifting it.
+ *
+ * But also notice how the next_input_bit() bits we're shifting into
+ * the remainder don't actually affect any decision-making until
+ * 32 bits later.  Thus, the first 32 cycles of this are pretty boring.
+ * Also, to add the CRC to a message, we need a 32-bit-long hole for it at
+ * the end, so we have to add 32 extra cycles shifting in zeros at the
+ * end of every message,
+ *
+ * So the standard trick is to rearrage merging in the next_input_bit()
+ * until the moment it's needed.  Then the first 32 cycles can be precomputed,
+ * and merging in the final 32 zero bits to make room for the CRC can be
+ * skipped entirely.
+ * This changes the code to:
+ * for (i = 0; i < input_bits; i++) {
+ *      remainder ^= next_input_bit() << 31;
+ * 	multiple = (remainder & 0x80000000) ? CRCPOLY : 0;
+ * 	remainder = (remainder << 1) ^ multiple;
+ * }
+ * With this optimization, the little-endian code is simpler:
+ * for (i = 0; i < input_bits; i++) {
+ *      remainder ^= next_input_bit();
+ * 	multiple = (remainder & 1) ? CRCPOLY : 0;
+ * 	remainder = (remainder >> 1) ^ multiple;
+ * }
+ *
+ * Note that the other details of endianness have been hidden in CRCPOLY
+ * (which must be bit-reversed) and next_input_bit().
+ *
+ * However, as long as next_input_bit is returning the bits in a sensible
+ * order, we can actually do the merging 8 or more bits at a time rather
+ * than one bit at a time:
+ * for (i = 0; i < input_bytes; i++) {
+ * 	remainder ^= next_input_byte() << 24;
+ * 	for (j = 0; j < 8; j++) {
+ * 		multiple = (remainder & 0x80000000) ? CRCPOLY : 0;
+ * 		remainder = (remainder << 1) ^ multiple;
+ * 	}
+ * }
+ * Or in little-endian:
+ * for (i = 0; i < input_bytes; i++) {
+ * 	remainder ^= next_input_byte();
+ * 	for (j = 0; j < 8; j++) {
+ * 		multiple = (remainder & 1) ? CRCPOLY : 0;
+ * 		remainder = (remainder << 1) ^ multiple;
+ * 	}
+ * }
+ * If the input is a multiple of 32 bits, you can even XOR in a 32-bit
+ * word at a time and increase the inner loop count to 32.
+ *
+ * You can also mix and match the two loop styles, for example doing the
+ * bulk of a message byte-at-a-time and adding bit-at-a-time processing
+ * for any fractional bytes at the end.
+ *
+ * The only remaining optimization is to the byte-at-a-time table method.
+ * Here, rather than just shifting one bit of the remainder to decide
+ * in the correct multiple to subtract, we can shift a byte at a time.
+ * This produces a 40-bit (rather than a 33-bit) intermediate remainder,
+ * but again the multiple of the polynomial to subtract depends only on
+ * the high bits, the high 8 bits in this case.  
+ *
+ * The multile we need in that case is the low 32 bits of a 40-bit
+ * value whose high 8 bits are given, and which is a multiple of the
+ * generator polynomial.  This is simply the CRC-32 of the given
+ * one-byte message.
+ *
+ * Two more details: normally, appending zero bits to a message which
+ * is already a multiple of a polynomial produces a larger multiple of that
+ * polynomial.  To enable a CRC to detect this condition, it's common to
+ * invert the CRC before appending it.  This makes the remainder of the
+ * message+crc come out not as zero, but some fixed non-zero value.
+ *
+ * The same problem applies to zero bits prepended to the message, and
+ * a similar solution is used.  Instead of starting with a remainder of
+ * 0, an initial remainder of all ones is used.  As long as you start
+ * the same way on decoding, it doesn't make a difference.
+ */
+
+#if UNITTEST
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#if 0				/*Not used at present */
+static void
+buf_dump(char const *prefix, unsigned char const *buf, size_t len)
+{
+	fputs(prefix, stdout);
+	while (len--)
+		printf(" %02x", *buf++);
+	putchar('\n');
+
+}
+#endif
+
+static u32 attribute((const)) bitreverse(u32 x)
+{
+	x = (x >> 16) | (x << 16);
+	x = (x >> 8 & 0x00ff00ff) | (x << 8 & 0xff00ff00);
+	x = (x >> 4 & 0x0f0f0f0f) | (x << 4 & 0xf0f0f0f0);
+	x = (x >> 2 & 0x33333333) | (x << 2 & 0xcccccccc);
+	x = (x >> 1 & 0x55555555) | (x << 1 & 0xaaaaaaaa);
+	return x;
+}
+
+static void bytereverse(unsigned char *buf, size_t len)
+{
+	while (len--) {
+		unsigned char x = *buf;
+		x = (x >> 4) | (x << 4);
+		x = (x >> 2 & 0x33) | (x << 2 & 0xcc);
+		x = (x >> 1 & 0x55) | (x << 1 & 0xaa);
+		*buf++ = x;
+	}
+}
+
+static void random_garbage(unsigned char *buf, size_t len)
+{
+	while (len--)
+		*buf++ = (unsigned char) random();
+}
+
+#if 0				/* Not used at present */
+static void store_le(u32 x, unsigned char *buf)
+{
+	buf[0] = (unsigned char) x;
+	buf[1] = (unsigned char) (x >> 8);
+	buf[2] = (unsigned char) (x >> 16);
+	buf[3] = (unsigned char) (x >> 24);
+}
+#endif
+
+static void store_be(u32 x, unsigned char *buf)
+{
+	buf[0] = (unsigned char) (x >> 24);
+	buf[1] = (unsigned char) (x >> 16);
+	buf[2] = (unsigned char) (x >> 8);
+	buf[3] = (unsigned char) x;
+}
+
+/*
+ * This checks that CRC(buf + CRC(buf)) = 0, and that
+ * CRC commutes with bit-reversal.  This has the side effect
+ * of bytewise bit-reversing the input buffer, and returns
+ * the CRC of the reversed buffer.
+ */
+static u32 test_step(u32 init, unsigned char *buf, size_t len)
+{
+	u32 crc1, crc2;
+	size_t i;
+
+	crc1 = crc32_be(init, buf, len);
+	store_be(crc1, buf + len);
+	crc2 = crc32_be(init, buf, len + 4);
+	if (crc2)
+		printf("\nCRC cancellation fail: 0x%08x should be 0\n",
+		       crc2);
+
+	for (i = 0; i <= len + 4; i++) {
+		crc2 = crc32_be(init, buf, i);
+		crc2 = crc32_be(crc2, buf + i, len + 4 - i);
+		if (crc2)
+			printf("\nCRC split fail: 0x%08x\n", crc2);
+	}
+
+	/* Now swap it around for the other test */
+
+	bytereverse(buf, len + 4);
+	init = bitreverse(init);
+	crc2 = bitreverse(crc1);
+	if (crc1 != bitreverse(crc2))
+		printf("\nBit reversal fail: 0x%08x -> %0x08x -> 0x%08x\n",
+		       crc1, crc2, bitreverse(crc2));
+	crc1 = crc32_le(init, buf, len);
+	if (crc1 != crc2)
+		printf("\nCRC endianness fail: 0x%08x != 0x%08x\n", crc1,
+		       crc2);
+	crc2 = crc32_le(init, buf, len + 4);
+	if (crc2)
+		printf("\nCRC cancellation fail: 0x%08x should be 0\n",
+		       crc2);
+
+	for (i = 0; i <= len + 4; i++) {
+		crc2 = crc32_le(init, buf, i);
+		crc2 = crc32_le(crc2, buf + i, len + 4 - i);
+		if (crc2)
+			printf("\nCRC split fail: 0x%08x\n", crc2);
+	}
+
+	return crc1;
+}
+
+#define SIZE 64
+#define INIT1 0
+#define INIT2 0
+
+int main(void)
+{
+	unsigned char buf1[SIZE + 4];
+	unsigned char buf2[SIZE + 4];
+	unsigned char buf3[SIZE + 4];
+	int i, j;
+	u32 crc1, crc2, crc3;
+
+	crc32init_le();
+	crc32init_be();
+
+	for (i = 0; i <= SIZE; i++) {
+		printf("\rTesting length %d...", i);
+		fflush(stdout);
+		random_garbage(buf1, i);
+		random_garbage(buf2, i);
+		for (j = 0; j < i; j++)
+			buf3[j] = buf1[j] ^ buf2[j];
+
+		crc1 = test_step(INIT1, buf1, i);
+		crc2 = test_step(INIT2, buf2, i);
+		/* Now check that CRC(buf1 ^ buf2) = CRC(buf1) ^ CRC(buf2) */
+		crc3 = test_step(INIT1 ^ INIT2, buf3, i);
+		if (crc3 != (crc1 ^ crc2))
+			printf("CRC XOR fail: 0x%08x != 0x%08x ^ 0x%08x\n",
+			       crc3, crc1, crc2);
+	}
+	printf("\nAll test complete.  No failures expected.\n");
+	return 0;
+}
+
+#endif				/* UNITTEST */
+
+/**
+ * init_crc32(): generates CRC32 tables
+ * 
+ * On successful initialization, use count is increased.
+ * This guarantees that the library functions will stay resident
+ * in memory, and prevents someone from 'rmmod crc32' while
+ * a driver that needs it is still loaded.
+ * This also greatly simplifies drivers, as there's no need
+ * to call an initialization/cleanup function from each driver.
+ * Since crc32.o is a library module, there's no requirement
+ * that the user can unload it.
+ */
+static int __init init_crc32(void)
+{
+	int rc1, rc2, rc;
+	rc1 = crc32init_le();
+	rc2 = crc32init_be();
+	rc = rc1 || rc2;
+	if (!rc) MOD_INC_USE_COUNT;
+	return rc;
+}
+
+/**
+ * cleanup_crc32(): frees crc32 data when no longer needed
+ */
+static void __exit cleanup_crc32(void)
+{
+	crc32cleanup_le();
+	crc32cleanup_be();
+}
+
+module_init(init_crc32);
+module_exit(cleanup_crc32);
+
+EXPORT_SYMBOL(crc32_le);
+EXPORT_SYMBOL(crc32_be);
--- old/lib/Config.in	Fri Oct 11 12:30:19 2002
+++ new/lib/Config.in	Fri Oct 11 11:56:55 2002
@@ -4,6 +4,8 @@
 mainmenu_option next_comment
 comment 'Library routines'
 
+tristate 'CRC32 functions' CONFIG_CRC32
+
 #
 # Do we need the compression support?
 #
--- old/dev/null	Thu Aug 30 22:30:55 2001
+++ new/fs/Makefile.lib	Fri Oct 11 11:58:22 2002
@@ -0,0 +1,2 @@
+obj-$(CONFIG_JFFS2_FS)		+= crc32.o
+obj-$(CONFIG_EFI_PARTITION)	+= crc32.o
--- old/dev/null	Thu Aug 30 22:30:55 2001
+++ new/drivers/net/Makefile.lib	Fri Oct 11 11:59:12 2002
@@ -0,0 +1,69 @@
+# These drivers all require crc32.o
+obj-$(CONFIG_8139CP)		+= crc32.o
+obj-$(CONFIG_8139TOO)		+= crc32.o
+obj-$(CONFIG_A2065)		+= crc32.o
+obj-$(CONFIG_ARM_AM79C961A)	+= crc32.o
+obj-$(CONFIG_AT1700)		+= crc32.o
+obj-$(CONFIG_ATP)		+= crc32.o
+obj-$(CONFIG_DE2104X)		+= crc32.o
+obj-$(CONFIG_DE4X5)		+= crc32.o
+obj-$(CONFIG_DECLANCE)		+= crc32.o
+obj-$(CONFIG_DEPCA)		+= crc32.o
+obj-$(CONFIG_DL2K)		+= crc32.o
+obj-$(CONFIG_DM9102)		+= crc32.o
+obj-$(CONFIG_EPIC100)		+= crc32.o
+obj-$(CONFIG_EWRK3)		+= crc32.o
+obj-$(CONFIG_FEALNX)		+= crc32.o
+obj-$(CONFIG_HAPPYMEAL)		+= crc32.o
+obj-$(CONFIG_MACE)		+= crc32.o	
+obj-$(CONFIG_MACMACE)		+= crc32.o
+obj-$(CONFIG_MIPS_AU1000_ENET)	+= crc32.o
+obj-$(CONFIG_NATSEMI)		+= crc32.o	
+obj-$(CONFIG_PCMCIA_FMVJ18X)	+= crc32.o
+obj-$(CONFIG_PCMCIA_SMC91C92)	+= crc32.o
+obj-$(CONFIG_PCMCIA_XIRTULIP)	+= crc32.o
+obj-$(CONFIG_PCNET32)		+= crc32.o
+obj-$(CONFIG_SIS900)		+= crc32.o
+obj-$(CONFIG_SMC9194)		+= crc32.o
+obj-$(CONFIG_ADAPTEC_STARFIRE)	+= crc32.o
+obj-$(CONFIG_SUNBMAC)		+= crc32.o
+obj-$(CONFIG_SUNDANCE)		+= crc32.o
+obj-$(CONFIG_SUNGEM)		+= crc32.o
+obj-$(CONFIG_SUNGEM)		+= crc32.o
+obj-$(CONFIG_SUNLANCE)		+= crc32.o
+obj-$(CONFIG_SUNQE)		+= crc32.o
+obj-$(CONFIG_TULIP)		+= crc32.o
+obj-$(CONFIG_VIA_RHINE)		+= crc32.o
+obj-$(CONFIG_YELLOWFIN)		+= crc32.o
+obj-$(CONFIG_WINBOND_840)	+= crc32.o
+
+
+# These rely on drivers/net/7990.o which requires crc32.o
+obj-$(CONFIG_HPLANCE)		+= crc32.o	
+obj-$(CONFIG_MVME147_NET)	+= crc32.o	
+
+
+# These rely on drivers/net/8390.o which requires crc32.o
+obj-$(CONFIG_OAKNET)		+= crc32.o
+obj-$(CONFIG_NE2K_PCI)		+= crc32.o
+obj-$(CONFIG_STNIC)		+= crc32.o
+obj-$(CONFIG_MAC8390)		+= crc32.o
+obj-$(CONFIG_APNE)		+= crc32.o
+obj-$(CONFIG_PCMCIA_PCNET)	+= crc32.o
+obj-$(CONFIG_ARM_ETHERH)	+= crc32.o
+obj-$(CONFIG_WD80x3)		+= crc32.o
+obj-$(CONFIG_EL2)		+= crc32.o
+obj-$(CONFIG_NE2000)		+= crc32.o
+obj-$(CONFIG_NE2_MCA)		+= crc32.o
+obj-$(CONFIG_HPLAN)		+= crc32.o
+obj-$(CONFIG_HPLAN_PLUS)	+= crc32.o
+obj-$(CONFIG_ULTRA)		+= crc32.o
+obj-$(CONFIG_ULTRAMCA)		+= crc32.o
+obj-$(CONFIG_ULTRA32)		+= crc32.o
+obj-$(CONFIG_E2100)		+= crc32.o
+obj-$(CONFIG_ES3210)		+= crc32.o
+obj-$(CONFIG_LNE390)		+= crc32.o
+obj-$(CONFIG_NE3210)		+= crc32.o
+obj-$(CONFIG_AC3200)		+= crc32.o
+obj-$(CONFIG_ARIADNE2)		+= crc32.o
+obj-$(CONFIG_HYDRA)		+= crc32.o
--- old/dev/null	Thu Aug 30 22:30:55 2001
+++ new/drivers/usb/Makefile.lib	Fri Oct 11 12:00:07 2002
@@ -0,0 +1 @@
+obj-$(CONFIG_USB_CATC)		+= crc32.o


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