aboutsummaryrefslogtreecommitdiff
path: root/arch/ia64/lib/bitop.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/ia64/lib/bitop.c')
-rw-r--r--arch/ia64/lib/bitop.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/ia64/lib/bitop.c b/arch/ia64/lib/bitop.c
new file mode 100644
index 000000000000..82e299c8464e
--- /dev/null
+++ b/arch/ia64/lib/bitop.c
@@ -0,0 +1,88 @@
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/intrinsics.h>
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+/*
+ * Find next zero bit in a bitmap reasonably efficiently..
+ */
+
+int __find_next_zero_bit (const void *addr, unsigned long size, unsigned long offset)
+{
+ unsigned long *p = ((unsigned long *) addr) + (offset >> 6);
+ unsigned long result = offset & ~63UL;
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 63UL;
+ if (offset) {
+ tmp = *(p++);
+ tmp |= ~0UL >> (64-offset);
+ if (size < 64)
+ goto found_first;
+ if (~tmp)
+ goto found_middle;
+ size -= 64;
+ result += 64;
+ }
+ while (size & ~63UL) {
+ if (~(tmp = *(p++)))
+ goto found_middle;
+ result += 64;
+ size -= 64;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+found_first:
+ tmp |= ~0UL << size;
+ if (tmp == ~0UL) /* any bits zero? */
+ return result + size; /* nope */
+found_middle:
+ return result + ffz(tmp);
+}
+EXPORT_SYMBOL(__find_next_zero_bit);
+
+/*
+ * Find next bit in a bitmap reasonably efficiently..
+ */
+int __find_next_bit(const void *addr, unsigned long size, unsigned long offset)
+{
+ unsigned long *p = ((unsigned long *) addr) + (offset >> 6);
+ unsigned long result = offset & ~63UL;
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 63UL;
+ if (offset) {
+ tmp = *(p++);
+ tmp &= ~0UL << offset;
+ if (size < 64)
+ goto found_first;
+ if (tmp)
+ goto found_middle;
+ size -= 64;
+ result += 64;
+ }
+ while (size & ~63UL) {
+ if ((tmp = *(p++)))
+ goto found_middle;
+ result += 64;
+ size -= 64;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+ found_first:
+ tmp &= ~0UL >> (64-size);
+ if (tmp == 0UL) /* Are any bits set? */
+ return result + size; /* Nope. */
+ found_middle:
+ return result + __ffs(tmp);
+}
+EXPORT_SYMBOL(__find_next_bit);