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Diffstat (limited to 'arch/x86/lib/bitops_32.c')
-rw-r--r--arch/x86/lib/bitops_32.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/arch/x86/lib/bitops_32.c b/arch/x86/lib/bitops_32.c
new file mode 100644
index 000000000000..afd0045595d4
--- /dev/null
+++ b/arch/x86/lib/bitops_32.c
@@ -0,0 +1,70 @@
+#include <linux/bitops.h>
+#include <linux/module.h>
+
+/**
+ * find_next_bit - find the first 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
+ */
+int find_next_bit(const unsigned long *addr, int size, int offset)
+{
+ const unsigned long *p = addr + (offset >> 5);
+ int set = 0, bit = offset & 31, res;
+
+ if (bit) {
+ /*
+ * Look for nonzero in the first 32 bits:
+ */
+ __asm__("bsfl %1,%0\n\t"
+ "jne 1f\n\t"
+ "movl $32, %0\n"
+ "1:"
+ : "=r" (set)
+ : "r" (*p >> bit));
+ if (set < (32 - bit))
+ return set + offset;
+ set = 32 - bit;
+ p++;
+ }
+ /*
+ * No set bit yet, search remaining full words for a bit
+ */
+ res = find_first_bit (p, size - 32 * (p - addr));
+ return (offset + set + res);
+}
+EXPORT_SYMBOL(find_next_bit);
+
+/**
+ * find_next_zero_bit - find the first zero 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
+ */
+int find_next_zero_bit(const unsigned long *addr, int size, int offset)
+{
+ const unsigned long *p = addr + (offset >> 5);
+ int set = 0, bit = offset & 31, res;
+
+ if (bit) {
+ /*
+ * Look for zero in the first 32 bits.
+ */
+ __asm__("bsfl %1,%0\n\t"
+ "jne 1f\n\t"
+ "movl $32, %0\n"
+ "1:"
+ : "=r" (set)
+ : "r" (~(*p >> bit)));
+ if (set < (32 - bit))
+ return set + offset;
+ set = 32 - bit;
+ p++;
+ }
+ /*
+ * No zero yet, search remaining full bytes for a zero
+ */
+ res = find_first_zero_bit(p, size - 32 * (p - addr));
+ return (offset + set + res);
+}
+EXPORT_SYMBOL(find_next_zero_bit);