raid: Fix doc and base functions for min sources

The raid functions xor_gen, pq_gen and check functions
must have at least two sources. Fixes #175

Change-Id: I2e4509e037c2b1dc88f3f7449d80f4c763e1e124
Signed-off-by: Greg Tucker <[email protected]>

Author: gbtucker

include/raid.h

@@ -52,7 +52,7 @@ extern "C" {
  * This function determines what instruction sets are enabled and
  * selects the appropriate version at runtime.
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 2.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to source and dest. For XOR the dest is
  *                the last pointer. ie array[vects-1]. Src and dest
@@ -70,7 +70,7 @@ int xor_gen(int vects, int len, void **array);
  * This function determines what instruction sets are enabled and
  * selects the appropriate version at runtime.
  *
- * @param vects   Number of vectors in array.
+ * @param vects   Number of vectors in array. Must be > 1.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to vectors. Src and dest pointers
  *                must be aligned to 16B.
@@ -87,7 +87,7 @@ int xor_check(int vects, int len, void **array);
  * This function determines what instruction sets are enabled and
  * selects the appropriate version at runtime.
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 3.
  * @param len     Length of each vector in bytes. Must be 32B aligned.
  * @param array   Array of pointers to source and dest. For P+Q the dest
  *                is the last two pointers. ie array[vects-2],
@@ -107,7 +107,7 @@ int pq_gen(int vects, int len, void **array);
  * This function determines what instruction sets are enabled and
  * selects the appropriate version at runtime.
  *
- * @param vects  Number of vectors in array including P&Q.
+ * @param vects  Number of vectors in array including P&Q. Must be > 3.
  * @param len    Length of each vector in bytes. Must be 16B aligned.
  * @param array  Array of pointers to source and P, Q. P and Q parity
  *               are assumed to be the last two pointers in the array.
@@ -127,7 +127,7 @@ int pq_check(int vects, int len, void **array);
  * @brief Generate XOR parity vector from N sources.
  * @requires SSE4.1
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 2.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to source and dest. For XOR the dest is
  *                the last pointer. ie array[vects-1]. Src and dest pointers
@@ -143,7 +143,7 @@ int xor_gen_sse(int vects, int len, void **array);
  * @brief Generate XOR parity vector from N sources.
  * @requires AVX
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 2.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to source and dest. For XOR the dest is
  *                the last pointer. ie array[vects-1]. Src and dest pointers
@@ -159,7 +159,7 @@ int xor_gen_avx(int vects, int len, void **array);
  * @brief Checks that array has XOR parity sum of 0 across all vectors.
  * @requires SSE4.1
  *
- * @param vects   Number of vectors in array.
+ * @param vects   Number of vectors in array. Must be > 1.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to vectors. Src and dest pointers
  *                must be aligned to 16B.
@@ -174,7 +174,7 @@ int xor_check_sse(int vects, int len, void **array);
  * @brief Generate P+Q parity vectors from N sources.
  * @requires SSE4.1
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 3.
  * @param len     Length of each vector in bytes. Must be 16B aligned.
  * @param array   Array of pointers to source and dest. For P+Q the dest
  *                is the last two pointers. ie array[vects-2],
@@ -192,7 +192,7 @@ int pq_gen_sse(int vects, int len, void **array);
  * @brief Generate P+Q parity vectors from N sources.
  * @requires AVX
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 3.
  * @param len     Length of each vector in bytes. Must be 16B aligned.
  * @param array   Array of pointers to source and dest. For P+Q the dest
  *                is the last two pointers. ie array[vects-2],
@@ -210,7 +210,7 @@ int pq_gen_avx(int vects, int len, void **array);
  * @brief Generate P+Q parity vectors from N sources.
  * @requires AVX2
  *
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 3.
  * @param len     Length of each vector in bytes. Must be 32B aligned.
  * @param array   Array of pointers to source and dest. For P+Q the dest
  *                is the last two pointers. ie array[vects-2],
@@ -228,7 +228,7 @@ int pq_gen_avx2(int vects, int len, void **array);
  * @brief Checks that array of N sources, P and Q are consistent across all vectors.
  * @requires SSE4.1
  *
- * @param vects  Number of vectors in array including P&Q.
+ * @param vects  Number of vectors in array including P&Q. Must be > 3.
  * @param len    Length of each vector in bytes. Must be 16B aligned.
  * @param array  Array of pointers to source and P, Q. P and Q parity
                  are assumed to be the last two pointers in the array.
@@ -242,7 +242,7 @@ int pq_check_sse(int vects, int len, void **array);
 
 /**
  * @brief Generate P+Q parity vectors from N sources, runs baseline version.
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 3.
  * @param len     Length of each vector in bytes. Must be 16B aligned.
  * @param array   Array of pointers to source and dest. For P+Q the dest
  * 		  is the last two pointers. ie array[vects-2],
@@ -258,7 +258,7 @@ int pq_gen_base(int vects, int len, void **array);
 
 /**
  * @brief Generate XOR parity vector from N sources, runs baseline version.
- * @param vects   Number of source+dest vectors in array.
+ * @param vects   Number of source+dest vectors in array. Must be > 2.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to source and dest. For XOR the dest is
  * 		  the last pointer. ie array[vects-1]. Src and dest pointers
@@ -273,7 +273,7 @@ int xor_gen_base(int vects, int len, void **array);
 /**
  * @brief Checks that array has XOR parity sum of 0 across all vectors, runs baseline version.
  *
- * @param vects   Number of vectors in array.
+ * @param vects   Number of vectors in array. Must be > 1.
  * @param len     Length of each vector in bytes.
  * @param array   Array of pointers to vectors. Src and dest pointers
  *                must be aligned to 16B.
@@ -287,7 +287,7 @@ int xor_check_base(int vects, int len, void **array);
 /**
  * @brief Checks that array of N sources, P and Q are consistent across all vectors, runs baseline version.
  *
- * @param vects  Number of vectors in array including P&Q.
+ * @param vects  Number of vectors in array including P&Q. Must be > 3.
  * @param len    Length of each vector in bytes. Must be 16B aligned.
  * @param array  Array of pointers to source and P, Q. P and Q parity
  *               are assumed to be the last two pointers in the array.

raid/raid_base.c

@@ -47,6 +47,9 @@ int pq_gen_base(int vects, int len, void **array)
 	unsigned long **src = (unsigned long **)array;
 	int blocks = len / sizeof(long);
 
+	if (vects < 4)
+		return 1;	// Must have at least 2 src and 2 dest
+
 	for (i = 0; i < blocks; i++) {
 		q = p = src[vects - 3][i];
 
@@ -69,6 +72,9 @@ int pq_check_base(int vects, int len, void **array)
 	unsigned char p, q, s;
 	unsigned char **src = (unsigned char **)array;
 
+	if (vects < 4)
+		return 1;	// Must have at least 2 src and 2 dest
+
 	for (i = 0; i < len; i++) {
 		q = p = src[vects - 3][i];
 
@@ -94,6 +100,9 @@ int xor_gen_base(int vects, int len, void **array)
 	unsigned char parity;
 	unsigned char **src = (unsigned char **)array;
 
+	if (vects < 3)
+		return 1;	// Must have at least 2 src and 1 dest
+
 	for (i = 0; i < len; i++) {
 		parity = src[0][i];
 		for (j = 1; j < vects - 1; j++)
@@ -113,6 +122,9 @@ int xor_check_base(int vects, int len, void **array)
 	unsigned char parity;
 	unsigned char **src = (unsigned char **)array;
 
+	if (vects < 2)
+		return 1;	// Must have at least 2 src
+
 	for (i = 0; i < len; i++) {
 		parity = 0;
 		for (j = 0; j < vects; j++)