lib: Simple bitmap library

We add simple bitmap library which will help us create and maintain
bitmaps. It will also help us create a simple HART mask library.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

include/sbi/sbi_bitmap.h

@@ -0,0 +1,128 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ */
+
+#ifndef __SBI_BITMAP_H__
+#define __SBI_BITMAP_H__
+
+#include <sbi/sbi_bitops.h>
+
+#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
+#define BITMAP_LAST_WORD_MASK(nbits)					\
+(									\
+	((nbits) % BITS_PER_LONG) ?					\
+		((1UL << ((nbits) % BITS_PER_LONG)) - 1) : ~0UL		\
+)
+
+#define small_const_nbits(nbits) \
+	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
+
+#define DECLARE_BITMAP(name, nbits)	unsigned long name[BITS_TO_LONGS(nbits)]
+#define DEFINE_BITMAP(name)		extern unsigned long name[]
+
+static inline unsigned long bitmap_estimate_size(int nbits)
+{
+	return (BITS_TO_LONGS(nbits) * sizeof(unsigned long));
+}
+
+void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
+		  const unsigned long *bitmap2, int bits);
+void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
+		 const unsigned long *bitmap2, int bits);
+void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
+		  const unsigned long *bitmap2, int bits);
+
+static inline void bitmap_set(unsigned long *bmap, int start, int len)
+{
+	int bit;
+	for (bit = start; bit < (start + len); bit++)
+		bmap[BIT_WORD(bit)] |= (0x1UL << BIT_WORD_OFFSET(bit));
+}
+
+static inline void bitmap_clear(unsigned long *bmap, int start, int len)
+{
+	int bit;
+	for (bit = start; bit < (start + len); bit++)
+		bmap[BIT_WORD(bit)] &= ~(0x1UL << BIT_WORD_OFFSET(bit));
+}
+
+static inline void bitmap_zero(unsigned long *dst, int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = 0UL;
+	else {
+		size_t i, len = BITS_TO_LONGS(nbits);
+		for (i = 0; i < len; i++)
+			dst[i] = 0;
+	}
+}
+
+static inline void bitmap_zero_except(unsigned long *dst,
+				      int exception, int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = 0UL;
+	else {
+		size_t i, len = BITS_TO_LONGS(nbits);
+		for (i = 0; i < len; i++)
+			dst[i] = 0;
+	}
+	if (exception < nbits)
+		__set_bit(exception, dst);
+}
+
+static inline void bitmap_fill(unsigned long *dst, int nbits)
+{
+	size_t i, nlongs = BITS_TO_LONGS(nbits);
+	if (!small_const_nbits(nbits)) {
+		for (i = 0; i < (nlongs - 1); i++)
+			dst[i] = -1UL;
+	}
+	dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
+}
+
+static inline void bitmap_copy(unsigned long *dst,
+			       const unsigned long *src, int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = *src;
+	else {
+		size_t i, len = BITS_TO_LONGS(nbits);
+		for (i = 0; i < len; i++)
+			dst[i] = src[i];
+	}
+}
+
+static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
+			      const unsigned long *src2, int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = *src1 & *src2;
+	else
+		__bitmap_and(dst, src1, src2, nbits);
+}
+
+static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
+			     const unsigned long *src2, int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = *src1 | *src2;
+	else
+		__bitmap_or(dst, src1, src2, nbits);
+}
+
+static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
+			      const unsigned long *src2, int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = *src1 ^ *src2;
+	else
+		__bitmap_xor(dst, src1, src2, nbits);
+}
+
+#endif

lib/sbi/objects.mk

@@ -12,6 +12,7 @@ libsbi-objs-y += riscv_atomic.o
 libsbi-objs-y += riscv_hardfp.o
 libsbi-objs-y += riscv_locks.o
 
+libsbi-objs-y += sbi_bitmap.o
 libsbi-objs-y += sbi_bitops.o
 libsbi-objs-y += sbi_console.o
 libsbi-objs-y += sbi_ecall.o

lib/sbi/sbi_bitmap.c

@@ -0,0 +1,40 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Anup Patel <anup.patel@wdc.com>
+ */
+
+#include <sbi/sbi_bitmap.h>
+
+void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
+		  const unsigned long *bitmap2, int bits)
+{
+	int k;
+	int nr = BITS_TO_LONGS(bits);
+
+	for (k = 0; k < nr; k++)
+		dst[k] = bitmap1[k] & bitmap2[k];
+}
+
+void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
+		 const unsigned long *bitmap2, int bits)
+{
+	int k;
+	int nr = BITS_TO_LONGS(bits);
+
+	for (k = 0; k < nr; k++)
+		dst[k] = bitmap1[k] | bitmap2[k];
+}
+
+void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
+		  const unsigned long *bitmap2, int bits)
+{
+	int k;
+	int nr = BITS_TO_LONGS(bits);
+
+	for (k = 0; k < nr; k++)
+		dst[k] = bitmap1[k] ^ bitmap2[k];
+}