patch-2.1.51 linux/include/asm-ppc/bitops.h

• Lines: 309
• Date: Sat Aug 16 09:51:09 1997
• Orig file: v2.1.50/linux/include/asm-ppc/bitops.h
• Orig date: Mon Aug 4 16:25:39 1997

diff -u --recursive --new-file v2.1.50/linux/include/asm-ppc/bitops.h linux/include/asm-ppc/bitops.h
@@ -1,17 +1,26 @@
+/*
+ * $Id: bitops.h,v 1.7 1997/08/03 00:12:07 paulus Exp $
+ * bitops.h: Bit string operations on the ppc
+ */
+
 #ifndef _ASM_PPC_BITOPS_H_
 #define _ASM_PPC_BITOPS_H_
 
 #include <asm/system.h>
 #include <asm/byteorder.h>
-#include <linux/kernel.h> /* for printk */
-
-#define BIT(n) 1<<(n&0x1F)
-typedef unsigned long BITFIELD;
 
+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);
 
 /*
- * These are ifdef'd out here because using : "cc" as a constraing
+ * These are if'd out here because using : "cc" as a constraint
  * results in errors from gcc. -- Cort
+ * Besides, they need to be changed so we have both set_bit
+ * and test_and_set_bit, etc.
  */
 #if 0
 extern __inline__ int set_bit(int nr, void * addr)
@@ -20,9 +29,6 @@
 	unsigned long mask = 1 << (nr & 0x1f);
 	unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
 	
-	if ((unsigned long)addr & 3)
-		printk("set_bit(%lx, %p)\n", nr, addr);
-
 	__asm__ __volatile__(
 		"1:lwarx %0,0,%3 \n\t"
 		"or	%1,%0,%2 \n\t"
@@ -32,7 +38,7 @@
 		: "r" (mask), "r" (p)
 		/*: "cc" */);
 
-n	return (old & mask) != 0;
+	return (old & mask) != 0;
 }
 
 extern __inline__  unsigned long clear_bit(unsigned long nr, void *addr)
@@ -41,8 +47,6 @@
 	unsigned long mask = 1 << (nr & 0x1f);
 	unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
 
-	if ((unsigned long)addr & 3)
-		printk("clear_bit(%lx, %p)\n", nr, addr);
 	__asm__ __volatile__("\n\
 1:	lwarx	%0,0,%3
 	andc	%1,%0,%2
@@ -61,8 +65,6 @@
 	unsigned long mask = 1 << (nr & 0x1f);
 	unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
 
-	if ((unsigned long)addr & 3)
-		printk("change_bit(%lx, %p)\n", nr, addr);
 	__asm__ __volatile__("\n\
 1:	lwarx	%0,0,%3
 	xor	%1,%0,%2
@@ -76,10 +78,19 @@
 }
 #endif
 
+extern __inline__ unsigned long test_bit(int nr, __const__ volatile void *addr)
+{
+	__const__ unsigned int *p = (__const__ unsigned int *) addr;
+
+	return (p[nr >> 5] >> (nr & 0x1f)) & 1UL;
+}
+
 extern __inline__ int ffz(unsigned int x)
 {
 	int n;
 
+	if (x == ~0)
+		return 32;
 	x = ~x & (x+1);		/* set LS zero to 1, other bits to 0 */
 	__asm__ ("cntlzw %0,%1" : "=r" (n) : "r" (x));
 	return 31 - n;
@@ -89,34 +100,11 @@
  * This implementation of find_{first,next}_zero_bit was stolen from
  * Linus' asm-alpha/bitops.h.
  */
+#define find_first_zero_bit(addr, size) \
+	find_next_zero_bit((addr), (size), 0)
 
-extern __inline__ unsigned long find_first_zero_bit(void * addr, unsigned long size)
-{
-	unsigned int * p = ((unsigned int *) addr);
-	unsigned int result = 0;
-	unsigned int tmp;
-
-	if (size == 0)
-		return 0;
-	while (size & ~31UL) {
-		if (~(tmp = *(p++)))
-			goto found_middle;
-		result += 32;
-		size -= 32;
-	}
-	if (!size)
-		return result;
-	tmp = *p;
-	tmp |= ~0UL << size;
-found_middle:
-	return result + ffz(tmp);
-}
-
-/*
- * Find next zero bit in a bitmap reasonably efficiently..
- */
-extern __inline__ unsigned long find_next_zero_bit(void * addr, unsigned long size,
-				 unsigned long offset)
+extern __inline__ unsigned long find_next_zero_bit(void * addr,
+	unsigned long size, unsigned long offset)
 {
 	unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
 	unsigned int result = offset & ~31UL;
@@ -127,17 +115,17 @@
 	size -= result;
 	offset &= 31UL;
 	if (offset) {
-		tmp = *(p++);
+		tmp = *p++;
 		tmp |= ~0UL >> (32-offset);
 		if (size < 32)
 			goto found_first;
-		if (~tmp)
+		if (tmp != ~0U)
 			goto found_middle;
 		size -= 32;
 		result += 32;
 	}
-	while (size & ~31UL) {
-		if (~(tmp = *(p++)))
+	while (size >= 32) {
+		if ((tmp = *p++) != ~0U)
 			goto found_middle;
 		result += 32;
 		size -= 32;
@@ -153,101 +141,98 @@
 
 
 #define _EXT2_HAVE_ASM_BITOPS_
-#define ext2_find_first_zero_bit(addr, size) \
-        ext2_find_next_zero_bit((addr), (size), 0)
 
+#ifdef __KERNEL__
+/*
+ * test_and_{set,clear}_bit guarantee atomicity without
+ * disabling interrupts.
+ */
+#define ext2_set_bit(nr, addr)		test_and_set_bit((nr) ^ 0x18, addr)
+#define ext2_clear_bit(nr, addr)	test_and_clear_bit((nr) ^ 0x18, addr)
 
+#else
 extern __inline__ int ext2_set_bit(int nr, void * addr)
 {
-#ifdef __KERNEL__
-  int s = _disable_interrupts();
-#endif
-  int			mask;
-  unsigned char	*ADDR = (unsigned char *) addr;
-  int oldbit;
-  
-  ADDR += nr >> 3;
-  mask = 1 << (nr & 0x07);
-  oldbit = (*ADDR & mask) ? 1 : 0;
-  *ADDR |= mask;
-#ifdef __KERNEL__	
-  _enable_interrupts(s);
-#endif
-  return oldbit;
+	int		mask;
+	unsigned char	*ADDR = (unsigned char *) addr;
+	int oldbit;
+
+	ADDR += nr >> 3;
+	mask = 1 << (nr & 0x07);
+	oldbit = (*ADDR & mask) ? 1 : 0;
+	*ADDR |= mask;
+	return oldbit;
 }
 
 extern __inline__ int ext2_clear_bit(int nr, void * addr)
 {
-#ifdef __KERNEL__
-  int s = _disable_interrupts();
-#endif
-  int		mask;
-  unsigned char	*ADDR = (unsigned char *) addr;
-  int oldbit;
-  
-  ADDR += nr >> 3;
-  mask = 1 << (nr & 0x07);
-  oldbit = (*ADDR & mask) ? 1 : 0;
-  *ADDR = *ADDR & ~mask;
-#ifdef __KERNEL__	
-  _enable_interrupts(s);
-#endif
-  return oldbit;
-}
+	int		mask;
+	unsigned char	*ADDR = (unsigned char *) addr;
+	int oldbit;
 
-
-/* The following routine need not be atomic. */
-extern __inline__ unsigned long test_bit(int nr, void *addr)
-{
-	return 1UL & (((__const__ unsigned int *) addr)[nr >> 5] >> (nr & 31));
+	ADDR += nr >> 3;
+	mask = 1 << (nr & 0x07);
+	oldbit = (*ADDR & mask) ? 1 : 0;
+	*ADDR = *ADDR & ~mask;
+	return oldbit;
 }
+#endif	/* __KERNEL__ */
 
 extern __inline__ int ext2_test_bit(int nr, __const__ void * addr)
 {
-	int			mask;
 	__const__ unsigned char	*ADDR = (__const__ unsigned char *) addr;
 
-	ADDR += nr >> 3;
-	mask = 1 << (nr & 0x07);
-	return ((mask & *ADDR) != 0);
+	return (ADDR[nr >> 3] >> (nr & 7)) & 1;
 }
 
-extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
+/*
+ * This implementation of ext2_find_{first,next}_zero_bit was stolen from
+ * Linus' asm-alpha/bitops.h and modified for a big-endian machine.
+ */
+
+#define ext2_find_first_zero_bit(addr, size) \
+        ext2_find_next_zero_bit((addr), (size), 0)
+
+extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
+	unsigned long size, unsigned long offset)
 {
-	unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
-	unsigned long result = offset & ~31UL;
-	unsigned long tmp;
+	unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
+	unsigned int result = offset & ~31UL;
+	unsigned int tmp;
 
 	if (offset >= size)
 		return size;
 	size -= result;
 	offset &= 31UL;
-	if(offset) {
-		tmp = *(p++);
-		tmp |= le32_to_cpu(~0UL >> (32-offset));
-		if(size < 32)
+	if (offset) {
+		tmp = cpu_to_le32p(p++);
+		tmp |= ~0UL >> (32-offset);
+		if (size < 32)
 			goto found_first;
-		if(~tmp)
+		if (tmp != ~0U)
 			goto found_middle;
 		size -= 32;
 		result += 32;
 	}
-	while(size & ~31UL) {
-		if(~(tmp = *(p++)))
+	while (size >= 32) {
+		if ((tmp = cpu_to_le32p(p++)) != ~0U)
 			goto found_middle;
 		result += 32;
 		size -= 32;
 	}
-	if(!size)
+	if (!size)
 		return result;
-	tmp = *p;
-
+	tmp = cpu_to_le32p(p);
 found_first:
-	return result + ffz(le32_to_cpu(tmp) | (~0UL << size));
+	tmp |= ~0U << size;
 found_middle:
-	return result + ffz(le32_to_cpu(tmp));
+	return result + ffz(tmp);
 }
 
-#endif /* _ASM_PPC_BITOPS_H */
-
+/* Bitmap functions for the minix filesystem.  */
+#define minix_set_bit(nr,addr) ext2_set_bit(nr,addr)
+#define minix_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
+#define minix_test_bit(nr,addr) ext2_test_bit(nr,addr)
+#define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size)
 
+#endif /* _ASM_PPC_BITOPS_H */