[PATCH] bitops: generic ext2_{set,clear,test,find_first_zero,find_next_zero}_bit()

This patch introduces the C-language equivalents of the functions below: int ext2_set_bit(int nr, volatile unsigned long *addr); int ext2_clear_bit(int nr, volatile unsigned long *addr); int ext2_test_bit(int nr, const volatile unsigned long *addr); unsigned long ext2_find_first_zero_bit(const unsigned long *addr, unsigned long size); unsinged long ext2_find_next_zero_bit(const unsigned long *addr, unsigned long size); In include/asm-generic/bitops/ext2-non-atomic.h This code largely copied from: include/asm-powerpc/bitops.h include/asm-parisc/bitops.h Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] bitops: generic ext2_{set,clear,test,find_first_zero,find_next_zero}_bit()
This patch introduces the C-language equivalents of the functions below: int ext2_set_bit(int nr, volatile unsigned long *addr); int ext2_clear_bit(int nr, volatile unsigned long *addr); int ext2_test_bit(int nr, const volatile unsigned long *addr); unsigned long ext2_find_first_zero_bit(const unsigned long *addr, unsigned long size); unsinged long ext2_find_next_zero_bit(const unsigned long *addr, unsigned long size); In include/asm-generic/bitops/ext2-non-atomic.h This code largely copied from: include/asm-powerpc/bitops.h include/asm-parisc/bitops.h Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Akinobu Mita · Linus Torvalds
1 parent a54baa1487
Showing 3 changed files with 144 additions and 0 deletions Side-by-side Diff
include/asm-generic/bitops/ext2-non-atomic.h
include/asm-generic/bitops/le.h
lib/find_next_bit.c
+#ifndef _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_
+#define _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_
+
+#include <asm-generic/bitops/le.h>
+
+#define ext2_set_bit(nr,addr)	\
+	generic___test_and_set_le_bit((nr),(unsigned long *)(addr))
+#define ext2_clear_bit(nr,addr)	\
+	generic___test_and_clear_le_bit((nr),(unsigned long *)(addr))
+
+#define ext2_test_bit(nr,addr)	\
+	generic_test_le_bit((nr),(unsigned long *)(addr))
+#define ext2_find_first_zero_bit(addr, size) \
+	generic_find_first_zero_le_bit((unsigned long *)(addr), (size))
+#define ext2_find_next_zero_bit(addr, size, off) \
+	generic_find_next_zero_le_bit((unsigned long *)(addr), (size), (off))
+
+#endif /* _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_ */
+#ifndef _ASM_GENERIC_BITOPS_LE_H_
+#define _ASM_GENERIC_BITOPS_LE_H_
+
+#include <asm/types.h>
+#include <asm/byteorder.h>
+
+#define BITOP_WORD(nr)		((nr) / BITS_PER_LONG)
+#define BITOP_LE_SWIZZLE	((BITS_PER_LONG-1) & ~0x7)
+
+#if defined(__LITTLE_ENDIAN)
+
+#define generic_test_le_bit(nr, addr) test_bit(nr, addr)
+#define generic___set_le_bit(nr, addr) __set_bit(nr, addr)
+#define generic___clear_le_bit(nr, addr) __clear_bit(nr, addr)
+
+#define generic_test_and_set_le_bit(nr, addr) test_and_set_bit(nr, addr)
+#define generic_test_and_clear_le_bit(nr, addr) test_and_clear_bit(nr, addr)
+
+#define generic___test_and_set_le_bit(nr, addr) __test_and_set_bit(nr, addr)
+#define generic___test_and_clear_le_bit(nr, addr) __test_and_clear_bit(nr, addr)
+
+#define generic_find_next_zero_le_bit(addr, size, offset) find_next_zero_bit(addr, size, offset)
+
+#elif defined(__BIG_ENDIAN)
+
+#define generic_test_le_bit(nr, addr) \
+	test_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+#define generic___set_le_bit(nr, addr) \
+	__set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+#define generic___clear_le_bit(nr, addr) \
+	__clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+
+#define generic_test_and_set_le_bit(nr, addr) \
+	test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+#define generic_test_and_clear_le_bit(nr, addr) \
+	test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+
+#define generic___test_and_set_le_bit(nr, addr) \
+	__test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+#define generic___test_and_clear_le_bit(nr, addr) \
+	__test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
+
+extern unsigned long generic_find_next_zero_le_bit(const unsigned long *addr,
+		unsigned long size, unsigned long offset);
+
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+
+#define generic_find_first_zero_le_bit(addr, size) \
+        generic_find_next_zero_le_bit((addr), (size), 0)
+
+#endif /* _ASM_GENERIC_BITOPS_LE_H_ */
@@ -12,6 +12,7 @@
 #include <linux/bitops.h>
 #include <linux/module.h>
 #include <asm/types.h>
+#include <asm/byteorder.h>
  
 #define BITOP_WORD(nr)		((nr) / BITS_PER_LONG)
  
@@ -106,4 +107,76 @@
 }
  
 EXPORT_SYMBOL(find_next_zero_bit);
+
+#ifdef __BIG_ENDIAN
+
+/* include/linux/byteorder does not support "unsigned long" type */
+static inline unsigned long ext2_swabp(const unsigned long * x)
+{
+#if BITS_PER_LONG == 64
+	return (unsigned long) __swab64p((u64 *) x);
+#elif BITS_PER_LONG == 32
+	return (unsigned long) __swab32p((u32 *) x);
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+/* include/linux/byteorder doesn't support "unsigned long" type */
+static inline unsigned long ext2_swab(const unsigned long y)
+{
+#if BITS_PER_LONG == 64
+	return (unsigned long) __swab64((u64) y);
+#elif BITS_PER_LONG == 32
+	return (unsigned long) __swab32((u32) y);
+#else
+#error BITS_PER_LONG not defined
+#endif
+}
+
+unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned
+		long size, unsigned long offset)
+{
+	const unsigned long *p = addr + BITOP_WORD(offset);
+	unsigned long result = offset & ~(BITS_PER_LONG - 1);
+	unsigned long tmp;
+
+	if (offset >= size)
+		return size;
+	size -= result;
+	offset &= (BITS_PER_LONG - 1UL);
+	if (offset) {
+		tmp = ext2_swabp(p++);
+		tmp |= (~0UL >> (BITS_PER_LONG - offset));
+		if (size < BITS_PER_LONG)
+			goto found_first;
+		if (~tmp)
+			goto found_middle;
+		size -= BITS_PER_LONG;
+		result += BITS_PER_LONG;
+	}
+
+	while (size & ~(BITS_PER_LONG - 1)) {
+		if (~(tmp = *(p++)))
+			goto found_middle_swap;
+		result += BITS_PER_LONG;
+		size -= BITS_PER_LONG;
+	}
+	if (!size)
+		return result;
+	tmp = ext2_swabp(p);
+found_first:
+	tmp |= ~0UL << size;
+	if (tmp == ~0UL)	/* Are any bits zero? */
+		return result + size; /* Nope. Skip ffz */
+found_middle:
+	return result + ffz(tmp);
+
+found_middle_swap:
+	return result + ffz(ext2_swab(tmp));
+}
+
+EXPORT_SYMBOL(generic_find_next_zero_le_bit);
+
+#endif /* __BIG_ENDIAN */
	1	+#ifndef _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_
	2	+#define _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_
	3	+
	4	+#include <asm-generic/bitops/le.h>
	5	+
	6	+#define ext2_set_bit(nr,addr) \
	7	+ generic___test_and_set_le_bit((nr),(unsigned long *)(addr))
	8	+#define ext2_clear_bit(nr,addr) \
	9	+ generic___test_and_clear_le_bit((nr),(unsigned long *)(addr))
	10	+
	11	+#define ext2_test_bit(nr,addr) \
	12	+ generic_test_le_bit((nr),(unsigned long *)(addr))
	13	+#define ext2_find_first_zero_bit(addr, size) \
	14	+ generic_find_first_zero_le_bit((unsigned long *)(addr), (size))
	15	+#define ext2_find_next_zero_bit(addr, size, off) \
	16	+ generic_find_next_zero_le_bit((unsigned long *)(addr), (size), (off))
	17	+
	18	+#endif /* _ASM_GENERIC_BITOPS_EXT2_NON_ATOMIC_H_ */
	1	+#ifndef _ASM_GENERIC_BITOPS_LE_H_
	2	+#define _ASM_GENERIC_BITOPS_LE_H_
	3	+
	4	+#include <asm/types.h>
	5	+#include <asm/byteorder.h>
	6	+
	7	+#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
	8	+#define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7)
	9	+
	10	+#if defined(__LITTLE_ENDIAN)
	11	+
	12	+#define generic_test_le_bit(nr, addr) test_bit(nr, addr)
	13	+#define generic___set_le_bit(nr, addr) __set_bit(nr, addr)
	14	+#define generic___clear_le_bit(nr, addr) __clear_bit(nr, addr)
	15	+
	16	+#define generic_test_and_set_le_bit(nr, addr) test_and_set_bit(nr, addr)
	17	+#define generic_test_and_clear_le_bit(nr, addr) test_and_clear_bit(nr, addr)
	18	+
	19	+#define generic___test_and_set_le_bit(nr, addr) __test_and_set_bit(nr, addr)
	20	+#define generic___test_and_clear_le_bit(nr, addr) __test_and_clear_bit(nr, addr)
	21	+
	22	+#define generic_find_next_zero_le_bit(addr, size, offset) find_next_zero_bit(addr, size, offset)
	23	+
	24	+#elif defined(__BIG_ENDIAN)
	25	+
	26	+#define generic_test_le_bit(nr, addr) \
	27	+ test_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	28	+#define generic___set_le_bit(nr, addr) \
	29	+ __set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	30	+#define generic___clear_le_bit(nr, addr) \
	31	+ __clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	32	+
	33	+#define generic_test_and_set_le_bit(nr, addr) \
	34	+ test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	35	+#define generic_test_and_clear_le_bit(nr, addr) \
	36	+ test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	37	+
	38	+#define generic___test_and_set_le_bit(nr, addr) \
	39	+ __test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	40	+#define generic___test_and_clear_le_bit(nr, addr) \
	41	+ __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
	42	+
	43	+extern unsigned long generic_find_next_zero_le_bit(const unsigned long *addr,
	44	+ unsigned long size, unsigned long offset);
	45	+
	46	+#else
	47	+#error "Please fix <asm/byteorder.h>"
	48	+#endif
	49	+
	50	+#define generic_find_first_zero_le_bit(addr, size) \
	51	+ generic_find_next_zero_le_bit((addr), (size), 0)
	52	+
	53	+#endif /* _ASM_GENERIC_BITOPS_LE_H_ */
...	...	@@ -12,6 +12,7 @@
12	12	#include <linux/bitops.h>
13	13	#include <linux/module.h>
14	14	#include <asm/types.h>
	15	+#include <asm/byteorder.h>
15	16
16	17	#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
17	18
...	...	@@ -106,4 +107,76 @@
106	107	}
107	108
108	109	EXPORT_SYMBOL(find_next_zero_bit);
	110	+
	111	+#ifdef __BIG_ENDIAN
	112	+
	113	+/* include/linux/byteorder does not support "unsigned long" type */
	114	+static inline unsigned long ext2_swabp(const unsigned long * x)
	115	+{
	116	+#if BITS_PER_LONG == 64
	117	+ return (unsigned long) __swab64p((u64 *) x);
	118	+#elif BITS_PER_LONG == 32
	119	+ return (unsigned long) __swab32p((u32 *) x);
	120	+#else
	121	+#error BITS_PER_LONG not defined
	122	+#endif
	123	+}
	124	+
	125	+/* include/linux/byteorder doesn't support "unsigned long" type */
	126	+static inline unsigned long ext2_swab(const unsigned long y)
	127	+{
	128	+#if BITS_PER_LONG == 64
	129	+ return (unsigned long) __swab64((u64) y);
	130	+#elif BITS_PER_LONG == 32
	131	+ return (unsigned long) __swab32((u32) y);
	132	+#else
	133	+#error BITS_PER_LONG not defined
	134	+#endif
	135	+}
	136	+
	137	+unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned
	138	+ long size, unsigned long offset)
	139	+{
	140	+ const unsigned long *p = addr + BITOP_WORD(offset);
	141	+ unsigned long result = offset & ~(BITS_PER_LONG - 1);
	142	+ unsigned long tmp;
	143	+
	144	+ if (offset >= size)
	145	+ return size;
	146	+ size -= result;
	147	+ offset &= (BITS_PER_LONG - 1UL);
	148	+ if (offset) {
	149	+ tmp = ext2_swabp(p++);
	150	+ tmp \|= (~0UL >> (BITS_PER_LONG - offset));
	151	+ if (size < BITS_PER_LONG)
	152	+ goto found_first;
	153	+ if (~tmp)
	154	+ goto found_middle;
	155	+ size -= BITS_PER_LONG;
	156	+ result += BITS_PER_LONG;
	157	+ }
	158	+
	159	+ while (size & ~(BITS_PER_LONG - 1)) {
	160	+ if (~(tmp = *(p++)))
	161	+ goto found_middle_swap;
	162	+ result += BITS_PER_LONG;
	163	+ size -= BITS_PER_LONG;
	164	+ }
	165	+ if (!size)
	166	+ return result;
	167	+ tmp = ext2_swabp(p);
	168	+found_first:
	169	+ tmp \|= ~0UL << size;
	170	+ if (tmp == ~0UL) /* Are any bits zero? */
	171	+ return result + size; /* Nope. Skip ffz */
	172	+found_middle:
	173	+ return result + ffz(tmp);
	174	+
	175	+found_middle_swap:
	176	+ return result + ffz(ext2_swab(tmp));
	177	+}
	178	+
	179	+EXPORT_SYMBOL(generic_find_next_zero_le_bit);
	180	+
	181	+#endif /* __BIG_ENDIAN */