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-rw-r--r--tools/testing/radix-tree/linux/bitops.h150
1 files changed, 150 insertions, 0 deletions
diff --git a/tools/testing/radix-tree/linux/bitops.h b/tools/testing/radix-tree/linux/bitops.h
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+++ b/tools/testing/radix-tree/linux/bitops.h
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+#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_
+#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_
+
+#include <linux/types.h>
+
+#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
+#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
+
+/**
+ * __set_bit - Set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Unlike set_bit(), this function is non-atomic and may be reordered.
+ * If it's called on the same region of memory simultaneously, the effect
+ * may be that only one operation succeeds.
+ */
+static inline void __set_bit(int nr, volatile unsigned long *addr)
+{
+ unsigned long mask = BITOP_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
+
+ *p |= mask;
+}
+
+static inline void __clear_bit(int nr, volatile unsigned long *addr)
+{
+ unsigned long mask = BITOP_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
+
+ *p &= ~mask;
+}
+
+/**
+ * __change_bit - Toggle a bit in memory
+ * @nr: the bit to change
+ * @addr: the address to start counting from
+ *
+ * Unlike change_bit(), this function is non-atomic and may be reordered.
+ * If it's called on the same region of memory simultaneously, the effect
+ * may be that only one operation succeeds.
+ */
+static inline void __change_bit(int nr, volatile unsigned long *addr)
+{
+ unsigned long mask = BITOP_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
+
+ *p ^= mask;
+}
+
+/**
+ * __test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.
+ * If two examples of this operation race, one can appear to succeed
+ * but actually fail. You must protect multiple accesses with a lock.
+ */
+static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
+{
+ unsigned long mask = BITOP_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
+ unsigned long old = *p;
+
+ *p = old | mask;
+ return (old & mask) != 0;
+}
+
+/**
+ * __test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to clear
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.
+ * If two examples of this operation race, one can appear to succeed
+ * but actually fail. You must protect multiple accesses with a lock.
+ */
+static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
+{
+ unsigned long mask = BITOP_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
+ unsigned long old = *p;
+
+ *p = old & ~mask;
+ return (old & mask) != 0;
+}
+
+/* WARNING: non atomic and it can be reordered! */
+static inline int __test_and_change_bit(int nr,
+ volatile unsigned long *addr)
+{
+ unsigned long mask = BITOP_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
+ unsigned long old = *p;
+
+ *p = old ^ mask;
+ return (old & mask) != 0;
+}
+
+/**
+ * test_bit - Determine whether a bit is set
+ * @nr: bit number to test
+ * @addr: Address to start counting from
+ */
+static inline int test_bit(int nr, const volatile unsigned long *addr)
+{
+ return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
+}
+
+/**
+ * __ffs - find first bit in word.
+ * @word: The word to search
+ *
+ * Undefined if no bit exists, so code should check against 0 first.
+ */
+static inline unsigned long __ffs(unsigned long word)
+{
+ int num = 0;
+
+ if ((word & 0xffffffff) == 0) {
+ num += 32;
+ word >>= 32;
+ }
+ if ((word & 0xffff) == 0) {
+ num += 16;
+ word >>= 16;
+ }
+ if ((word & 0xff) == 0) {
+ num += 8;
+ word >>= 8;
+ }
+ if ((word & 0xf) == 0) {
+ num += 4;
+ word >>= 4;
+ }
+ if ((word & 0x3) == 0) {
+ num += 2;
+ word >>= 2;
+ }
+ if ((word & 0x1) == 0)
+ num += 1;
+ return num;
+}
+
+unsigned long find_next_bit(const unsigned long *addr,
+ unsigned long size,
+ unsigned long offset);
+
+#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */