patch-2.4.2 linux/include/asm-cris/bitops.h
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- Lines: 185
- Date:
Thu Feb 8 16:32:44 2001
- Orig file:
v2.4.1/linux/include/asm-cris/bitops.h
- Orig date:
Wed Dec 31 16:00:00 1969
diff -u --recursive --new-file v2.4.1/linux/include/asm-cris/bitops.h linux/include/asm-cris/bitops.h
@@ -0,0 +1,184 @@
+/* $Id: bitops.h,v 1.3 2000/10/17 14:56:27 bjornw Exp $ */
+/* all of these should probably be rewritten in assembler for speed. */
+
+#ifndef _CRIS_BITOPS_H
+#define _CRIS_BITOPS_H
+
+#include <asm/system.h>
+
+/*
+ * These have to be done with inline assembly: that way the bit-setting
+ * is guaranteed to be atomic. 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).
+ */
+
+/*
+ * Some hacks to defeat gcc over-optimizations..
+ */
+struct __dummy { unsigned long a[100]; };
+#define ADDR (*(struct __dummy *) addr)
+#define CONST_ADDR (*(const struct __dummy *) addr)
+
+#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr)
+#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr)
+#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr)
+
+extern __inline__ int test_and_set_bit(int nr, void *addr)
+{
+ unsigned int mask, retval;
+ unsigned long flags;
+ unsigned int *adr = (unsigned int *)addr;
+
+ adr += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ save_flags(flags);
+ cli();
+ retval = (mask & *adr) != 0;
+ *adr |= mask;
+ restore_flags(flags);
+ return retval;
+}
+
+/*
+ * clear_bit() doesn't provide any barrier for the compiler.
+ */
+#define smp_mb__before_clear_bit() barrier()
+#define smp_mb__after_clear_bit() barrier()
+
+extern __inline__ int test_and_clear_bit(int nr, void *addr)
+{
+ unsigned int mask, retval;
+ unsigned long flags;
+ unsigned int *adr = (unsigned int *)addr;
+
+ adr += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ save_flags(flags);
+ cli();
+ retval = (mask & *adr) != 0;
+ *adr &= ~mask;
+ restore_flags(flags);
+ return retval;
+}
+
+extern __inline__ int test_and_change_bit(int nr, void *addr)
+{
+ unsigned int mask, retval;
+ unsigned long flags;
+ unsigned int *adr = (unsigned int *)addr;
+ adr += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ save_flags(flags);
+ cli();
+ retval = (mask & *adr) != 0;
+ *adr ^= mask;
+ restore_flags(flags);
+ return retval;
+}
+
+/*
+ * This routine doesn't need to be atomic.
+ */
+extern __inline__ int test_bit(int nr, const void *addr)
+{
+ unsigned int mask;
+ unsigned int *adr = (unsigned int *)addr;
+
+ adr += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ return ((mask & *adr) != 0);
+}
+
+/*
+ * Find-bit routines..
+ */
+
+/*
+ * 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)
+{
+ unsigned long result = 0;
+
+ while(word & 1) {
+ result++;
+ word >>= 1;
+ }
+ return result;
+}
+
+/*
+ * Find first one in word. Undefined if no one exists,
+ * so code should check against 0UL first..
+ */
+extern __inline__ unsigned long find_first_one(unsigned long word)
+{
+ unsigned long result = 0;
+
+ while(!(word & 1)) {
+ result++;
+ word >>= 1;
+ }
+ return result;
+}
+
+extern __inline__ int find_next_zero_bit (void * addr, int size, int offset)
+{
+ unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
+ unsigned long result = offset & ~31UL;
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset &= 31UL;
+ if (offset) {
+ tmp = *(p++);
+ tmp |= ~0UL >> (32-offset);
+ if (size < 32)
+ goto found_first;
+ if (~tmp)
+ goto found_middle;
+ size -= 32;
+ result += 32;
+ }
+ while (size & ~31UL) {
+ if (~(tmp = *(p++)))
+ goto found_middle;
+ result += 32;
+ size -= 32;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+
+ found_first:
+ tmp |= ~0UL >> size;
+ found_middle:
+ return result + ffz(tmp);
+}
+
+#define find_first_zero_bit(addr, size) \
+ find_next_zero_bit((addr), (size), 0)
+
+#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 /* _CRIS_BITOPS_H */
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