Linux 6.9-rc1
[linux-2.6-microblaze.git] / lib / find_bit.c
index 1b8e4b2..32f99e9 100644 (file)
 #include <linux/minmax.h>
 #include <linux/swab.h>
 
-#if !defined(find_next_bit) || !defined(find_next_zero_bit) ||                 \
-       !defined(find_next_bit_le) || !defined(find_next_zero_bit_le) ||        \
-       !defined(find_next_and_bit)
 /*
- * This is a common helper function for find_next_bit, find_next_zero_bit, and
- * find_next_and_bit. The differences are:
- *  - The "invert" argument, which is XORed with each fetched word before
- *    searching it for one bits.
- *  - The optional "addr2", which is anded with "addr1" if present.
+ * Common helper for find_bit() function family
+ * @FETCH: The expression that fetches and pre-processes each word of bitmap(s)
+ * @MUNGE: The expression that post-processes a word containing found bit (may be empty)
+ * @size: The bitmap size in bits
  */
-unsigned long _find_next_bit(const unsigned long *addr1,
-               const unsigned long *addr2, unsigned long nbits,
-               unsigned long start, unsigned long invert, unsigned long le)
-{
-       unsigned long tmp, mask;
-
-       if (unlikely(start >= nbits))
-               return nbits;
-
-       tmp = addr1[start / BITS_PER_LONG];
-       if (addr2)
-               tmp &= addr2[start / BITS_PER_LONG];
-       tmp ^= invert;
-
-       /* Handle 1st word. */
-       mask = BITMAP_FIRST_WORD_MASK(start);
-       if (le)
-               mask = swab(mask);
-
-       tmp &= mask;
+#define FIND_FIRST_BIT(FETCH, MUNGE, size)                                     \
+({                                                                             \
+       unsigned long idx, val, sz = (size);                                    \
+                                                                               \
+       for (idx = 0; idx * BITS_PER_LONG < sz; idx++) {                        \
+               val = (FETCH);                                                  \
+               if (val) {                                                      \
+                       sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(val)), sz);  \
+                       break;                                                  \
+               }                                                               \
+       }                                                                       \
+                                                                               \
+       sz;                                                                     \
+})
 
-       start = round_down(start, BITS_PER_LONG);
-
-       while (!tmp) {
-               start += BITS_PER_LONG;
-               if (start >= nbits)
-                       return nbits;
-
-               tmp = addr1[start / BITS_PER_LONG];
-               if (addr2)
-                       tmp &= addr2[start / BITS_PER_LONG];
-               tmp ^= invert;
-       }
-
-       if (le)
-               tmp = swab(tmp);
+/*
+ * Common helper for find_next_bit() function family
+ * @FETCH: The expression that fetches and pre-processes each word of bitmap(s)
+ * @MUNGE: The expression that post-processes a word containing found bit (may be empty)
+ * @size: The bitmap size in bits
+ * @start: The bitnumber to start searching at
+ */
+#define FIND_NEXT_BIT(FETCH, MUNGE, size, start)                               \
+({                                                                             \
+       unsigned long mask, idx, tmp, sz = (size), __start = (start);           \
+                                                                               \
+       if (unlikely(__start >= sz))                                            \
+               goto out;                                                       \
+                                                                               \
+       mask = MUNGE(BITMAP_FIRST_WORD_MASK(__start));                          \
+       idx = __start / BITS_PER_LONG;                                          \
+                                                                               \
+       for (tmp = (FETCH) & mask; !tmp; tmp = (FETCH)) {                       \
+               if ((idx + 1) * BITS_PER_LONG >= sz)                            \
+                       goto out;                                               \
+               idx++;                                                          \
+       }                                                                       \
+                                                                               \
+       sz = min(idx * BITS_PER_LONG + __ffs(MUNGE(tmp)), sz);                  \
+out:                                                                           \
+       sz;                                                                     \
+})
 
-       return min(start + __ffs(tmp), nbits);
-}
-EXPORT_SYMBOL(_find_next_bit);
-#endif
+#define FIND_NTH_BIT(FETCH, size, num)                                         \
+({                                                                             \
+       unsigned long sz = (size), nr = (num), idx, w, tmp;                     \
+                                                                               \
+       for (idx = 0; (idx + 1) * BITS_PER_LONG <= sz; idx++) {                 \
+               if (idx * BITS_PER_LONG + nr >= sz)                             \
+                       goto out;                                               \
+                                                                               \
+               tmp = (FETCH);                                                  \
+               w = hweight_long(tmp);                                          \
+               if (w > nr)                                                     \
+                       goto found;                                             \
+                                                                               \
+               nr -= w;                                                        \
+       }                                                                       \
+                                                                               \
+       if (sz % BITS_PER_LONG)                                                 \
+               tmp = (FETCH) & BITMAP_LAST_WORD_MASK(sz);                      \
+found:                                                                         \
+       sz = min(idx * BITS_PER_LONG + fns(tmp, nr), sz);                       \
+out:                                                                           \
+       sz;                                                                     \
+})
 
 #ifndef find_first_bit
 /*
@@ -77,14 +98,7 @@ EXPORT_SYMBOL(_find_next_bit);
  */
 unsigned long _find_first_bit(const unsigned long *addr, unsigned long size)
 {
-       unsigned long idx;
-
-       for (idx = 0; idx * BITS_PER_LONG < size; idx++) {
-               if (addr[idx])
-                       return min(idx * BITS_PER_LONG + __ffs(addr[idx]), size);
-       }
-
-       return size;
+       return FIND_FIRST_BIT(addr[idx], /* nop */, size);
 }
 EXPORT_SYMBOL(_find_first_bit);
 #endif
@@ -97,15 +111,7 @@ unsigned long _find_first_and_bit(const unsigned long *addr1,
                                  const unsigned long *addr2,
                                  unsigned long size)
 {
-       unsigned long idx, val;
-
-       for (idx = 0; idx * BITS_PER_LONG < size; idx++) {
-               val = addr1[idx] & addr2[idx];
-               if (val)
-                       return min(idx * BITS_PER_LONG + __ffs(val), size);
-       }
-
-       return size;
+       return FIND_FIRST_BIT(addr1[idx] & addr2[idx], /* nop */, size);
 }
 EXPORT_SYMBOL(_find_first_and_bit);
 #endif
@@ -116,16 +122,82 @@ EXPORT_SYMBOL(_find_first_and_bit);
  */
 unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size)
 {
-       unsigned long idx;
+       return FIND_FIRST_BIT(~addr[idx], /* nop */, size);
+}
+EXPORT_SYMBOL(_find_first_zero_bit);
+#endif
 
-       for (idx = 0; idx * BITS_PER_LONG < size; idx++) {
-               if (addr[idx] != ~0UL)
-                       return min(idx * BITS_PER_LONG + ffz(addr[idx]), size);
-       }
+#ifndef find_next_bit
+unsigned long _find_next_bit(const unsigned long *addr, unsigned long nbits, unsigned long start)
+{
+       return FIND_NEXT_BIT(addr[idx], /* nop */, nbits, start);
+}
+EXPORT_SYMBOL(_find_next_bit);
+#endif
 
-       return size;
+unsigned long __find_nth_bit(const unsigned long *addr, unsigned long size, unsigned long n)
+{
+       return FIND_NTH_BIT(addr[idx], size, n);
 }
-EXPORT_SYMBOL(_find_first_zero_bit);
+EXPORT_SYMBOL(__find_nth_bit);
+
+unsigned long __find_nth_and_bit(const unsigned long *addr1, const unsigned long *addr2,
+                                unsigned long size, unsigned long n)
+{
+       return FIND_NTH_BIT(addr1[idx] & addr2[idx], size, n);
+}
+EXPORT_SYMBOL(__find_nth_and_bit);
+
+unsigned long __find_nth_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
+                                unsigned long size, unsigned long n)
+{
+       return FIND_NTH_BIT(addr1[idx] & ~addr2[idx], size, n);
+}
+EXPORT_SYMBOL(__find_nth_andnot_bit);
+
+unsigned long __find_nth_and_andnot_bit(const unsigned long *addr1,
+                                       const unsigned long *addr2,
+                                       const unsigned long *addr3,
+                                       unsigned long size, unsigned long n)
+{
+       return FIND_NTH_BIT(addr1[idx] & addr2[idx] & ~addr3[idx], size, n);
+}
+EXPORT_SYMBOL(__find_nth_and_andnot_bit);
+
+#ifndef find_next_and_bit
+unsigned long _find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2,
+                                       unsigned long nbits, unsigned long start)
+{
+       return FIND_NEXT_BIT(addr1[idx] & addr2[idx], /* nop */, nbits, start);
+}
+EXPORT_SYMBOL(_find_next_and_bit);
+#endif
+
+#ifndef find_next_andnot_bit
+unsigned long _find_next_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
+                                       unsigned long nbits, unsigned long start)
+{
+       return FIND_NEXT_BIT(addr1[idx] & ~addr2[idx], /* nop */, nbits, start);
+}
+EXPORT_SYMBOL(_find_next_andnot_bit);
+#endif
+
+#ifndef find_next_or_bit
+unsigned long _find_next_or_bit(const unsigned long *addr1, const unsigned long *addr2,
+                                       unsigned long nbits, unsigned long start)
+{
+       return FIND_NEXT_BIT(addr1[idx] | addr2[idx], /* nop */, nbits, start);
+}
+EXPORT_SYMBOL(_find_next_or_bit);
+#endif
+
+#ifndef find_next_zero_bit
+unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits,
+                                        unsigned long start)
+{
+       return FIND_NEXT_BIT(~addr[idx], /* nop */, nbits, start);
+}
+EXPORT_SYMBOL(_find_next_zero_bit);
 #endif
 
 #ifndef find_last_bit
@@ -161,3 +233,38 @@ unsigned long find_next_clump8(unsigned long *clump, const unsigned long *addr,
        return offset;
 }
 EXPORT_SYMBOL(find_next_clump8);
+
+#ifdef __BIG_ENDIAN
+
+#ifndef find_first_zero_bit_le
+/*
+ * Find the first cleared bit in an LE memory region.
+ */
+unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size)
+{
+       return FIND_FIRST_BIT(~addr[idx], swab, size);
+}
+EXPORT_SYMBOL(_find_first_zero_bit_le);
+
+#endif
+
+#ifndef find_next_zero_bit_le
+unsigned long _find_next_zero_bit_le(const unsigned long *addr,
+                                       unsigned long size, unsigned long offset)
+{
+       return FIND_NEXT_BIT(~addr[idx], swab, size, offset);
+}
+EXPORT_SYMBOL(_find_next_zero_bit_le);
+#endif
+
+#ifndef find_next_bit_le
+unsigned long _find_next_bit_le(const unsigned long *addr,
+                               unsigned long size, unsigned long offset)
+{
+       return FIND_NEXT_BIT(addr[idx], swab, size, offset);
+}
+EXPORT_SYMBOL(_find_next_bit_le);
+
+#endif
+
+#endif /* __BIG_ENDIAN */