1 files changed, 60 insertions, 9 deletions

diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c
index 78ccd73a8841..24c59ded47a0 100644
--- a/lib/find_next_bit.c
+++ b/lib/find_next_bit.c
@@ -16,14 +16,12 @@
 
 #define BITOP_WORD(nr)          ((nr) / BITS_PER_LONG)
 
-/**
- * find_next_bit - find the next set bit in a memory region
- * @addr: The address to base the search on
- * @offset: The bitnumber to start searching at
- * @size: The maximum size to search
+#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
+/*
+ * Find the next set bit in a memory region.
  */
 unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
-                unsigned long offset)
+                            unsigned long offset)
 {
         const unsigned long *p = addr + BITOP_WORD(offset);
         unsigned long result = offset & ~(BITS_PER_LONG-1);
@@ -60,7 +58,6 @@ found_first:
 found_middle:
         return result + __ffs(tmp);
 }
-
 EXPORT_SYMBOL(find_next_bit);
 
 /*
@@ -68,7 +65,7 @@ EXPORT_SYMBOL(find_next_bit);
  * Linus' asm-alpha/bitops.h.
  */
 unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
-                unsigned long offset)
+                                 unsigned long offset)
 {
         const unsigned long *p = addr + BITOP_WORD(offset);
         unsigned long result = offset & ~(BITS_PER_LONG-1);
@@ -105,8 +102,62 @@ found_first:
 found_middle:
         return result + ffz(tmp);
 }
-
 EXPORT_SYMBOL(find_next_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
+
+#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
+/*
+ * Find the first set bit in a memory region.
+ */
+unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
+{
+        const unsigned long *p = addr;
+        unsigned long result = 0;
+        unsigned long tmp;
+
+        while (size & ~(BITS_PER_LONG-1)) {
+                if ((tmp = *(p++)))
+                        goto found;
+                result += BITS_PER_LONG;
+                size -= BITS_PER_LONG;
+        }
+        if (!size)
+                return result;
+
+        tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
+        if (tmp == 0UL)         /* Are any bits set? */
+                return result + size;   /* Nope. */
+found:
+        return result + __ffs(tmp);
+}
+EXPORT_SYMBOL(find_first_bit);
+
+/*
+ * Find the first cleared bit in a memory region.
+ */
+unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
+{
+        const unsigned long *p = addr;
+        unsigned long result = 0;
+        unsigned long tmp;
+
+        while (size & ~(BITS_PER_LONG-1)) {
+                if (~(tmp = *(p++)))
+                        goto found;
+                result += BITS_PER_LONG;
+                size -= BITS_PER_LONG;
+        }
+        if (!size)
+                return result;
+
+        tmp = (*p) | (~0UL << size);
+        if (tmp == ~0UL)        /* Are any bits zero? */
+                return result + size;   /* Nope. */
+found:
+        return result + ffz(tmp);
+}
+EXPORT_SYMBOL(find_first_zero_bit);
+#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
 
 #ifdef __BIG_ENDIAN