lib: Import few bitmap functions from Linux

Import few basic bitmap functions (bitmap_{weight,fill,set,clear,or}())
and their dependencies from Linux. These are required for upcoming DMA
resource allocation support for TI's K3 SoCs.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

include/linux/bitmap.h

@@ -5,10 +5,88 @@
 #include <asm/types.h>
 #include <linux/types.h>
 #include <linux/bitops.h>
+#include <linux/string.h>
 
+#ifdef __LITTLE_ENDIAN
+#define BITMAP_MEM_ALIGNMENT 8
+#else
+#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
+#endif
+#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
+
+#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
+#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 #define small_const_nbits(nbits) \
 	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
 
+static inline void
+__bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
+	    const unsigned long *bitmap2, unsigned int bits)
+{
+	unsigned int k;
+	unsigned int nr = BITS_TO_LONGS(bits);
+
+	for (k = 0; k < nr; k++)
+		dst[k] = bitmap1[k] | bitmap2[k];
+}
+
+static inline int
+__bitmap_weight(const unsigned long *bitmap, unsigned int bits)
+{
+	unsigned int k, lim = bits / BITS_PER_LONG;
+	int w = 0;
+
+	for (k = 0; k < lim; k++)
+		w += hweight_long(bitmap[k]);
+
+	if (bits % BITS_PER_LONG)
+		w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
+
+	return w;
+}
+
+static inline void
+__bitmap_set(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
+
+	while (len - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		len -= bits_to_set;
+		bits_to_set = BITS_PER_LONG;
+		mask_to_set = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
+		*p |= mask_to_set;
+	}
+}
+
+static inline void
+__bitmap_clear(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
+
+	while (len - bits_to_clear >= 0) {
+		*p &= ~mask_to_clear;
+		len -= bits_to_clear;
+		bits_to_clear = BITS_PER_LONG;
+		mask_to_clear = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
+		*p &= ~mask_to_clear;
+	}
+}
+
 static inline void bitmap_zero(unsigned long *dst, int nbits)
 {
 	if (small_const_nbits(nbits)) {
@@ -81,4 +159,59 @@ static inline unsigned long find_first_bit(const unsigned long *addr, unsigned l
 	     (bit) < (size);					\
 	     (bit) = find_next_bit((addr), (size), (bit) + 1))
 
+static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
+{
+	if (small_const_nbits(nbits)) {
+		*dst = ~0UL;
+	} else {
+		unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+
+		memset(dst, 0xff, len);
+	}
+}
+
+static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
+			     const unsigned long *src2, unsigned int nbits)
+{
+	if (small_const_nbits(nbits))
+		*dst = *src1 | *src2;
+	else
+		__bitmap_or(dst, src1, src2, nbits);
+}
+
+static inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
+{
+	if (small_const_nbits(nbits))
+		return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
+	return __bitmap_weight(src, nbits);
+}
+
+static inline void bitmap_set(unsigned long *map, unsigned int start,
+			      unsigned int nbits)
+{
+	if (__builtin_constant_p(nbits) && nbits == 1)
+		__set_bit(start, map);
+	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
+		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
+		memset((char *)map + start / 8, 0xff, nbits / 8);
+	else
+		__bitmap_set(map, start, nbits);
+}
+
+static inline void bitmap_clear(unsigned long *map, unsigned int start,
+				unsigned int nbits)
+{
+	if (__builtin_constant_p(nbits) && nbits == 1)
+		__clear_bit(start, map);
+	else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
+		 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
+		 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
+		memset((char *)map + start / 8, 0, nbits / 8);
+	else
+		__bitmap_clear(map, start, nbits);
+}
+
 #endif /* __LINUX_BITMAP_H */

include/linux/bitops.h

@@ -4,6 +4,7 @@
 #include <asm/types.h>
 #include <asm-generic/bitsperlong.h>
 #include <linux/compiler.h>
+#include <linux/kernel.h>
 
 #ifdef	__KERNEL__
 #define BIT(nr)			(1UL << (nr))
@@ -133,6 +134,17 @@ static inline unsigned int generic_hweight8(unsigned int w)
 	return (res & 0x0F) + ((res >> 4) & 0x0F);
 }
 
+static inline unsigned long generic_hweight64(__u64 w)
+{
+	return generic_hweight32((unsigned int)(w >> 32)) +
+	       generic_hweight32((unsigned int)w);
+}
+
+static inline unsigned long hweight_long(unsigned long w)
+{
+	return sizeof(w) == 4 ? generic_hweight32(w) : generic_hweight64(w);
+}
+
 #include <asm/bitops.h>
 
 /* linux/include/asm-generic/bitops/non-atomic.h */