[PATCH 1/5] sandbox: add generic find_next_zero_bit implementation

[lukas.funke-oss at weidmueller.com]

From: Lukas Funke <lukas.funke at weidmueller.com>

Add generic 'find_next_zero_bit' implementation in order to enable the
use of the 'for_each_set_bitrange' macro. The implementation is currently
missing for the sandbox-arch and using the function results in a linker
error.

There are more efficient implementations in the architecture specific
implementations. However, for the sandbox the implementation should be
simple and portable.

Signed-off-by: Lukas Funke <lukas.funke at weidmueller.com>
---

 arch/sandbox/include/asm/bitops.h | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/arch/sandbox/include/asm/bitops.h b/arch/sandbox/include/asm/bitops.h
index f27d5e98c5..453ff005d2 100644
--- a/arch/sandbox/include/asm/bitops.h
+++ b/arch/sandbox/include/asm/bitops.h
@@ -104,8 +104,20 @@ static inline int __test_and_change_bit(int nr, void *addr)
 	return (old & mask) != 0;
 }
 
-extern int find_first_zero_bit(void *addr, unsigned size);
-extern int find_next_zero_bit(void *addr, int size, int offset);
+#define find_first_zero_bit(addr, size) \
+	find_next_zero_bit((addr), (size), 0)
+
+static inline int find_next_zero_bit(const unsigned long *addr, int size,
+				     int offset) {
+	unsigned long *p = ((unsigned long *)addr) + (offset >> 5);
+
+	while ((~(*p) & 0x1 << offset) == 0x0ll && (offset < size)) {
+		offset++;
+		p = ((unsigned long *)addr) + (offset >> 5);
+	}
+
+	return offset;
+}
 
 /*
  * This routine doesn't need to be atomic.
-- 
2.30.2