crc32: add-real-8-bit.diff

Index: infiniband/lib/crc32.c
===================================================================
@@ -25,13 +25,13 @@
 #include <linux/types.h>
 #include "crc32defs.h"
 
-#if CRC_LE_BITS == 8
+#if CRC_LE_BITS > 8
 # define tole(x) (__force u32) __constant_cpu_to_le32(x)
 #else
 # define tole(x) (x)
 #endif
 
-#if CRC_BE_BITS == 8
+#if CRC_BE_BITS > 8
 # define tobe(x) (__force u32) __constant_cpu_to_be32(x)
 #else
 # define tobe(x) (x)

@@ -43,7 +43,7 @@ MODULE_AUTHOR("Matt Domsch <Matt_Domsch@
 MODULE_DESCRIPTION("Ethernet CRC32 calculations");
 MODULE_LICENSE("GPL");
 
-#if CRC_LE_BITS == 8 || CRC_BE_BITS == 8
+#if CRC_LE_BITS > 8 || CRC_BE_BITS > 8
 
 static inline u32
 crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256])

@@ -123,6 +123,12 @@ u32 __pure crc32_le(u32 crc, unsigned ch
 		crc = (crc >> 4) ^ crc32table_le[0][crc & 15];
 	}
 # elif CRC_LE_BITS == 8
+	/* aka Sarwate algorithm */
+	while (len--) {
+		crc ^= *p++;
+		crc = (crc >> 8) ^ crc32table_le[0][crc & 255];
+	}
+# else
 	const u32      (*tab)[] = crc32table_le;
 
 	crc = (__force u32) __cpu_to_le32(crc);

@@ -166,6 +172,11 @@ u32 __pure crc32_be(u32 crc, unsigned ch
 		crc = (crc << 4) ^ crc32table_be[0][crc >> 28];
 	}
 # elif CRC_BE_BITS == 8
+	while (len--) {
+		crc ^= *p++ << 24;
+		crc = (crc << 8) ^ crc32table_be[0][crc >> 24];
+	}
+# else
 	const u32      (*tab)[] = crc32table_be;
 
 	crc = (__force u32) __cpu_to_be32(crc);

Index: infiniband/lib/crc32defs.h
===================================================================
@@ -6,27 +6,29 @@
 #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 */
+/* How many bits at a time to use.  Valid values are 1, 2, 4, 8, and 32. */
+/* For less performance-sensitive, use 4 or 8 */
 #ifndef CRC_LE_BITS
-# define CRC_LE_BITS 8
+# define CRC_LE_BITS 32
 #endif
 #ifndef CRC_BE_BITS
-# define CRC_BE_BITS 8
+# define CRC_BE_BITS 32
 #endif
 
 /*
  * 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
+#if CRC_LE_BITS > 32 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
+	CRC_LE_BITS & CRC_LE_BITS-1
+# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32}"
 #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
+#if CRC_BE_BITS > 32 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
+	CRC_BE_BITS & CRC_BE_BITS-1
+# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32}"
 #endif

Index: infiniband/lib/gen_crc32table.c
===================================================================
@@ -4,11 +4,20 @@
 
 #define ENTRIES_PER_LINE 4
 
+#if CRC_LE_BITS <= 8
 #define LE_TABLE_SIZE (1 << CRC_LE_BITS)
+#else
+#define LE_TABLE_SIZE 256
+#endif
+
+#if CRC_BE_BITS <= 8
 #define BE_TABLE_SIZE (1 << CRC_BE_BITS)
+#else
+#define BE_TABLE_SIZE 256
+#endif
 
-static uint32_t crc32table_le[4][LE_TABLE_SIZE];
-static uint32_t crc32table_be[4][BE_TABLE_SIZE];
+static uint32_t crc32table_le[8][256];
+static uint32_t crc32table_be[8][256];
 
 /**
  * crc32init_le() - allocate and initialize LE table data

@@ -24,14 +33,14 @@ static void crc32init_le(void)
 
 	crc32table_le[0][0] = 0;
 
-	for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) {
+	for (i = LE_TABLE_SIZE >> 1; i; i >>= 1) {
 		crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
 		for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
 			crc32table_le[0][i + j] = crc ^ crc32table_le[0][j];
 	}
 	for (i = 0; i < LE_TABLE_SIZE; i++) {
 		crc = crc32table_le[0][i];
-		for (j = 1; j < 4; j++) {
+		for (j = 1; j < 8; j++) {
 			crc = crc32table_le[0][crc & 0xff] ^ (crc >> 8);
 			crc32table_le[j][i] = crc;
 		}

@@ -55,18 +64,18 @@ static void crc32init_be(void)
 	}
 	for (i = 0; i < BE_TABLE_SIZE; i++) {
 		crc = crc32table_be[0][i];
-		for (j = 1; j < 4; j++) {
+		for (j = 1; j < 8; j++) {
 			crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8);
 			crc32table_be[j][i] = crc;
 		}
 	}
 }
 
-static void output_table(uint32_t table[4][256], int len, char *trans)
+static void output_table(uint32_t table[8][256], int len, char *trans)
 {
 	int i, j;
 
-	for (j = 0 ; j < 4; j++) {
+	for (j = 0 ; j < 8; j++) {
 		printf("{");
 		for (i = 0; i < len - 1; i++) {
 			if (i % ENTRIES_PER_LINE == 0)

@@ -83,14 +92,14 @@ int main(int argc, char** argv)
 
 	if (CRC_LE_BITS > 1) {
 		crc32init_le();
-		printf("static const u32 crc32table_le[4][256] = {");
+		printf("static const u32 crc32table_le[8][256] = {");
 		output_table(crc32table_le, LE_TABLE_SIZE, "tole");
 		printf("};\n");
 	}
 
 	if (CRC_BE_BITS > 1) {
 		crc32init_be();
-		printf("static const u32 crc32table_be[4][256] = {");
+		printf("static const u32 crc32table_be[8][256] = {");
 		output_table(crc32table_be, BE_TABLE_SIZE, "tobe");
 		printf("};\n");
 	}