patch-2.1.80 linux/include/asm-arm/bitops.h

• Lines: 73
• Date: Tue Jan 20 16:39:42 1998
• Orig file: v2.1.79/linux/include/asm-arm/bitops.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.79/linux/include/asm-arm/bitops.h linux/include/asm-arm/bitops.h
@@ -0,0 +1,72 @@
+#ifndef __ASM_ARM_BITOPS_H
+#define __ASM_ARM_BITOPS_H
+
+/*
+ * Copyright 1995, Russell King.
+ * Various bits and pieces copyrights include:
+ *  Linus Torvalds (test_bit).
+ */
+
+/*
+ * These should be done with inline assembly.
+ * All bit operations return 0 if the bit
+ * was cleared before the operation and != 0 if it was not.
+ *
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ */
+
+/*
+ * Function prototypes to keep gcc -Wall happy
+ */
+extern void set_bit(int nr, volatile void * addr);
+extern void clear_bit(int nr, volatile void * addr);
+extern void change_bit(int nr, volatile void * addr);
+extern int test_and_set_bit(int nr, volatile void * addr);
+extern int test_and_clear_bit(int nr, volatile void * addr);
+extern int test_and_change_bit(int nr, volatile void * addr);
+extern int find_first_zero_bit(void * addr, unsigned size);
+extern int find_next_zero_bit(void * addr, int size, int offset);
+
+/*
+ * This routine doesn't need to be atomic.
+ */
+extern __inline__ int test_bit(int nr, const void * addr)
+{
+    return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
+}	
+
+/*
+ * ffz = Find First Zero in word. Undefined if no zero exists,
+ * so code should check against ~0UL first..
+ */
+extern __inline__ unsigned long ffz(unsigned long word)
+{
+	int k;
+
+	word = ~word;
+	k = 31;
+	if (word & 0x0000ffff) { k -= 16; word <<= 16; }
+	if (word & 0x00ff0000) { k -= 8;  word <<= 8;  }
+	if (word & 0x0f000000) { k -= 4;  word <<= 4;  }
+	if (word & 0x30000000) { k -= 2;  word <<= 2;  }
+	if (word & 0x40000000) { k -= 1; }
+        return k;
+}
+
+#ifdef __KERNEL__
+
+#define ext2_set_bit			test_and_set_bit
+#define ext2_clear_bit			test_and_clear_bit
+#define ext2_test_bit			test_bit
+#define ext2_find_first_zero_bit	find_first_zero_bit
+#define ext2_find_next_zero_bit		find_next_zero_bit
+
+/* Bitmap functions for the minix filesystem. */
+#define minix_set_bit(nr,addr)		test_and_set_bit(nr,addr)
+#define minix_clear_bit(nr,addr)	test_and_clear_bit(nr,addr)
+#define minix_test_bit(nr,addr)		test_bit(nr,addr)
+#define minix_find_first_zero_bit(addr,size)	find_first_zero_bit(addr,size)
+
+#endif /* __KERNEL__ */
+
+#endif /* _ARM_BITOPS_H */