better asm-generic/bitops.h

From: Pavel Machek (pavel@suse.cz)
Date: Fri Nov 10 2000 - 17:21:48 EST


Hi!

It might be usefull to someone..
                                                        Pavel

Index: bitops.h
===================================================================
RCS file: /home/cvs/Repository/linux/include/asm-generic/bitops.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 bitops.h
--- bitops.h 2000/09/04 16:50:34 1.1.1.1
+++ bitops.h 2000/11/09 13:23:02
@@ -1,5 +1,6 @@
 #ifndef _ASM_GENERIC_BITOPS_H_
 #define _ASM_GENERIC_BITOPS_H_
+#include <asm/system.h>
 
 /*
  * For the benefit of those who are trying to port Linux to another
@@ -13,43 +14,120 @@
  * You will have to change this if you are trying to port Linux to the
  * Alpha architecture or to a Cray. :-)
  *
- * C language equivalents written by Theodore Ts'o, 9/26/92
+ * C language equivalents written by Theodore Ts'o, 9/26/92
  */
 
-extern __inline__ int set_bit(int nr,int * addr)
+extern __inline__ int set_bit(int nr, void * a)
 {
         int mask, retval;
+ int *addr = a;
+ unsigned long flags;
 
         addr += nr >> 5;
         mask = 1 << (nr & 0x1f);
- cli();
+ save_flags(flags); cli();
         retval = (mask & *addr) != 0;
         *addr |= mask;
- sti();
+ restore_flags(flags);
         return retval;
 }
 
-extern __inline__ int clear_bit(int nr, int * addr)
+extern __inline__ int clear_bit(int nr, void * a)
 {
         int mask, retval;
+ int *addr = a;
+ unsigned long flags;
 
         addr += nr >> 5;
         mask = 1 << (nr & 0x1f);
- cli();
+ save_flags(flags); cli();
         retval = (mask & *addr) != 0;
         *addr &= ~mask;
- sti();
+ restore_flags(flags);
         return retval;
 }
 
-extern __inline__ int test_bit(int nr, int * addr)
+extern __inline__ int change_bit(int nr, void * a)
 {
+ int mask, retval;
+ int *addr = a;
+ unsigned long flags;
+
+ addr += nr >> 5;
+ mask = 1 << (nr & 0x1f);
+ save_flags(flags); cli();
+ retval = (mask & *addr) != 0;
+ *addr ^= mask;
+ restore_flags(flags);
+ return retval;
+}
+
+#define test_and_set_bit set_bit
+#define test_and_clear_bit clear_bit
+#define test_and_change_bit change_bit
+
+extern __inline__ int test_bit(int nr, void * a)
+{
         int mask;
+ int *addr = a;
 
         addr += nr >> 5;
         mask = 1 << (nr & 0x1f);
         return ((mask & *addr) != 0);
 }
+
+
+/*
+ * 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 i;
+ for (i=0; i<64; i++)
+ if (!(word & (1<<i)))
+ return i;
+ return -1;
+}
+
+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__
 

----- End forwarded message -----

-- 
I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care."
Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org
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This archive was generated by hypermail 2b29 : Wed Nov 15 2000 - 21:00:17 EST