[Xen-devel] [RFC PATCH COLO v5 08/29] tools/libxl: Introduce bitops macros

[Yang Hongyang <yanghy@xxxxxxxxxxxxxx>]

From: Wen Congyang <wency@xxxxxxxxxxxxxx>

This is the same set used by libxc.

Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
 tools/libxl/libxl_bitops.h | 79 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 tools/libxl/libxl_bitops.h

diff --git a/tools/libxl/libxl_bitops.h b/tools/libxl/libxl_bitops.h
new file mode 100644
index 0000000..c6ef8df
--- /dev/null
+++ b/tools/libxl/libxl_bitops.h
@@ -0,0 +1,79 @@
+#ifndef LIBXL_BITOPS_H
+#define LIBXL_BITOPS_H 1
+
+/* bitmap operations for single threaded access */
+
+#include <stdlib.h>
+#include <string.h>
+
+#define BITS_PER_LONG (sizeof(unsigned long) * 8)
+#define ORDER_LONG (sizeof(unsigned long) == 4 ? 5 : 6)
+
+#define BITMAP_ENTRY(_nr,_bmap) ((_bmap))[(_nr)/BITS_PER_LONG]
+#define BITMAP_SHIFT(_nr) ((_nr) % BITS_PER_LONG)
+
+/* calculate required space for number of longs needed to hold nr_bits */
+static inline int bitmap_size(int nr_bits)
+{
+    int nr_long, nr_bytes;
+    nr_long = (nr_bits + BITS_PER_LONG - 1) >> ORDER_LONG;
+    nr_bytes = nr_long * sizeof(unsigned long);
+    return nr_bytes;
+}
+
+static inline unsigned long *bitmap_alloc(int nr_bits)
+{
+    return calloc(1, bitmap_size(nr_bits));
+}
+
+static inline void bitmap_clear(unsigned long *addr, int nr_bits)
+{
+    memset(addr, 0, bitmap_size(nr_bits));
+}
+
+static inline int test_bit(int nr, unsigned long *addr)
+{
+    return (BITMAP_ENTRY(nr, addr) >> BITMAP_SHIFT(nr)) & 1;
+}
+
+static inline void clear_bit(int nr, unsigned long *addr)
+{
+    BITMAP_ENTRY(nr, addr) &= ~(1UL << BITMAP_SHIFT(nr));
+}
+
+static inline void set_bit(int nr, unsigned long *addr)
+{
+    BITMAP_ENTRY(nr, addr) |= (1UL << BITMAP_SHIFT(nr));
+}
+
+static inline int test_and_clear_bit(int nr, unsigned long *addr)
+{
+    int oldbit = test_bit(nr, addr);
+    clear_bit(nr, addr);
+    return oldbit;
+}
+
+static inline int test_and_set_bit(int nr, unsigned long *addr)
+{
+    int oldbit = test_bit(nr, addr);
+    set_bit(nr, addr);
+    return oldbit;
+}
+
+static inline void bitmap_or(unsigned long *dst, const unsigned long *other,
+                             int nr_bits)
+{
+    int i, nr_longs = (bitmap_size(nr_bits) / sizeof(unsigned long));
+    for ( i = 0; i < nr_longs; ++i )
+        dst[i] |= other[i];
+}
+
+#endif
+
+/*
+ * Local variables:
+ * mode: C
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
1.9.1


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