q3k/linux
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
linux/include/asm-s390/bitops.h
Martin Schwidefsky a22fb7ff12 [S390] find bit corner case. 
Fix [ext2_]find_first_[zero_]bit for the corner case of an all clear
or all set bit field by always handling that last word of the bit field
with __ffz_word/__ffs_word.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-02-19 15:29:33 +01:00

883 lines
23 KiB
C
Raw Blame History

#ifndef _S390_BITOPS_H
#define _S390_BITOPS_H
/*
* include/asm-s390/bitops.h
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Derived from "include/asm-i386/bitops.h"
* Copyright (C) 1992, Linus Torvalds
*
*/
#ifdef __KERNEL__
#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif
#include <linux/compiler.h>
/*
* 32 bit bitops format:
* bit 0 is the LSB of *addr; bit 31 is the MSB of *addr;
* bit 32 is the LSB of *(addr+4). That combined with the
* big endian byte order on S390 give the following bit
* order in memory:
* 1f 1e 1d 1c 1b 1a 19 18 17 16 15 14 13 12 11 10 \
* 0f 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00
* after that follows the next long with bit numbers
* 3f 3e 3d 3c 3b 3a 39 38 37 36 35 34 33 32 31 30
* 2f 2e 2d 2c 2b 2a 29 28 27 26 25 24 23 22 21 20
* The reason for this bit ordering is the fact that
* in the architecture independent code bits operations
* of the form "flags |= (1 << bitnr)" are used INTERMIXED
* with operation of the form "set_bit(bitnr, flags)".
*
* 64 bit bitops format:
* bit 0 is the LSB of *addr; bit 63 is the MSB of *addr;
* bit 64 is the LSB of *(addr+8). That combined with the
* big endian byte order on S390 give the following bit
* order in memory:
* 3f 3e 3d 3c 3b 3a 39 38 37 36 35 34 33 32 31 30
* 2f 2e 2d 2c 2b 2a 29 28 27 26 25 24 23 22 21 20
* 1f 1e 1d 1c 1b 1a 19 18 17 16 15 14 13 12 11 10
* 0f 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00
* after that follows the next long with bit numbers
* 7f 7e 7d 7c 7b 7a 79 78 77 76 75 74 73 72 71 70
* 6f 6e 6d 6c 6b 6a 69 68 67 66 65 64 63 62 61 60
* 5f 5e 5d 5c 5b 5a 59 58 57 56 55 54 53 52 51 50
* 4f 4e 4d 4c 4b 4a 49 48 47 46 45 44 43 42 41 40
* The reason for this bit ordering is the fact that
* in the architecture independent code bits operations
* of the form "flags |= (1 << bitnr)" are used INTERMIXED
* with operation of the form "set_bit(bitnr, flags)".
*/
/* bitmap tables from arch/S390/kernel/bitmap.S */
extern const char _oi_bitmap[];
extern const char _ni_bitmap[];
extern const char _zb_findmap[];
extern const char _sb_findmap[];
#ifndef __s390x__
#define __BITOPS_ALIGN 3
#define __BITOPS_WORDSIZE 32
#define __BITOPS_OR "or"
#define __BITOPS_AND "nr"
#define __BITOPS_XOR "xr"
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
#define __BITOPS_LOOP(__old, __new, __addr, __val, __op_string) \
asm volatile( \
" l %0,%2\n" \
"0: lr %1,%0\n" \
__op_string " %1,%3\n" \
" cs %0,%1,%2\n" \
" jl 0b" \
: "=&d" (__old), "=&d" (__new), \
"=Q" (*(unsigned long *) __addr) \
: "d" (__val), "Q" (*(unsigned long *) __addr) \
: "cc");
#else /* __GNUC__ */
#define __BITOPS_LOOP(__old, __new, __addr, __val, __op_string) \
asm volatile( \
" l %0,0(%4)\n" \
"0: lr %1,%0\n" \
__op_string " %1,%3\n" \
" cs %0,%1,0(%4)\n" \
" jl 0b" \
: "=&d" (__old), "=&d" (__new), \
"=m" (*(unsigned long *) __addr) \
: "d" (__val), "a" (__addr), \
"m" (*(unsigned long *) __addr) : "cc");
#endif /* __GNUC__ */
#else /* __s390x__ */
#define __BITOPS_ALIGN 7
#define __BITOPS_WORDSIZE 64
#define __BITOPS_OR "ogr"
#define __BITOPS_AND "ngr"
#define __BITOPS_XOR "xgr"
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
#define __BITOPS_LOOP(__old, __new, __addr, __val, __op_string) \
asm volatile( \
" lg %0,%2\n" \
"0: lgr %1,%0\n" \
__op_string " %1,%3\n" \
" csg %0,%1,%2\n" \
" jl 0b" \
: "=&d" (__old), "=&d" (__new), \
"=Q" (*(unsigned long *) __addr) \
: "d" (__val), "Q" (*(unsigned long *) __addr) \
: "cc");
#else /* __GNUC__ */
#define __BITOPS_LOOP(__old, __new, __addr, __val, __op_string) \
asm volatile( \
" lg %0,0(%4)\n" \
"0: lgr %1,%0\n" \
__op_string " %1,%3\n" \
" csg %0,%1,0(%4)\n" \
" jl 0b" \
: "=&d" (__old), "=&d" (__new), \
"=m" (*(unsigned long *) __addr) \
: "d" (__val), "a" (__addr), \
"m" (*(unsigned long *) __addr) : "cc");
#endif /* __GNUC__ */
#endif /* __s390x__ */
#define __BITOPS_WORDS(bits) (((bits)+__BITOPS_WORDSIZE-1)/__BITOPS_WORDSIZE)
#define __BITOPS_BARRIER() asm volatile("" : : : "memory")
#ifdef CONFIG_SMP
/*
* SMP safe set_bit routine based on compare and swap (CS)
*/
static inline void set_bit_cs(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr, old, new, mask;
addr = (unsigned long) ptr;
/* calculate address for CS */
addr += (nr ^ (nr & (__BITOPS_WORDSIZE - 1))) >> 3;
/* make OR mask */
mask = 1UL << (nr & (__BITOPS_WORDSIZE - 1));
/* Do the atomic update. */
__BITOPS_LOOP(old, new, addr, mask, __BITOPS_OR);
}
/*
* SMP safe clear_bit routine based on compare and swap (CS)
*/
static inline void clear_bit_cs(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr, old, new, mask;
addr = (unsigned long) ptr;
/* calculate address for CS */
addr += (nr ^ (nr & (__BITOPS_WORDSIZE - 1))) >> 3;
/* make AND mask */
mask = ~(1UL << (nr & (__BITOPS_WORDSIZE - 1)));
/* Do the atomic update. */
__BITOPS_LOOP(old, new, addr, mask, __BITOPS_AND);
}
/*
* SMP safe change_bit routine based on compare and swap (CS)
*/
static inline void change_bit_cs(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr, old, new, mask;
addr = (unsigned long) ptr;
/* calculate address for CS */
addr += (nr ^ (nr & (__BITOPS_WORDSIZE - 1))) >> 3;
/* make XOR mask */
mask = 1UL << (nr & (__BITOPS_WORDSIZE - 1));
/* Do the atomic update. */
__BITOPS_LOOP(old, new, addr, mask, __BITOPS_XOR);
}
/*
* SMP safe test_and_set_bit routine based on compare and swap (CS)
*/
static inline int
test_and_set_bit_cs(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr, old, new, mask;
addr = (unsigned long) ptr;
/* calculate address for CS */
addr += (nr ^ (nr & (__BITOPS_WORDSIZE - 1))) >> 3;
/* make OR/test mask */
mask = 1UL << (nr & (__BITOPS_WORDSIZE - 1));
/* Do the atomic update. */
__BITOPS_LOOP(old, new, addr, mask, __BITOPS_OR);
__BITOPS_BARRIER();
return (old & mask) != 0;
}
/*
* SMP safe test_and_clear_bit routine based on compare and swap (CS)
*/
static inline int
test_and_clear_bit_cs(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr, old, new, mask;
addr = (unsigned long) ptr;
/* calculate address for CS */
addr += (nr ^ (nr & (__BITOPS_WORDSIZE - 1))) >> 3;
/* make AND/test mask */
mask = ~(1UL << (nr & (__BITOPS_WORDSIZE - 1)));
/* Do the atomic update. */
__BITOPS_LOOP(old, new, addr, mask, __BITOPS_AND);
__BITOPS_BARRIER();
return (old ^ new) != 0;
}
/*
* SMP safe test_and_change_bit routine based on compare and swap (CS)
*/
static inline int
test_and_change_bit_cs(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr, old, new, mask;
addr = (unsigned long) ptr;
/* calculate address for CS */
addr += (nr ^ (nr & (__BITOPS_WORDSIZE - 1))) >> 3;
/* make XOR/test mask */
mask = 1UL << (nr & (__BITOPS_WORDSIZE - 1));
/* Do the atomic update. */
__BITOPS_LOOP(old, new, addr, mask, __BITOPS_XOR);
__BITOPS_BARRIER();
return (old & mask) != 0;
}
#endif /* CONFIG_SMP */
/*
* fast, non-SMP set_bit routine
*/
static inline void __set_bit(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
asm volatile(
" oc 0(1,%1),0(%2)"
: "=m" (*(char *) addr) : "a" (addr),
"a" (_oi_bitmap + (nr & 7)), "m" (*(char *) addr) : "cc" );
}
static inline void
__constant_set_bit(const unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
addr = ((unsigned long) ptr) + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
*(unsigned char *) addr |= 1 << (nr & 7);
}
#define set_bit_simple(nr,addr) \
(__builtin_constant_p((nr)) ? \
__constant_set_bit((nr),(addr)) : \
__set_bit((nr),(addr)) )
/*
* fast, non-SMP clear_bit routine
*/
static inline void
__clear_bit(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
asm volatile(
" nc 0(1,%1),0(%2)"
: "=m" (*(char *) addr) : "a" (addr),
"a" (_ni_bitmap + (nr & 7)), "m" (*(char *) addr) : "cc");
}
static inline void
__constant_clear_bit(const unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
addr = ((unsigned long) ptr) + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
*(unsigned char *) addr &= ~(1 << (nr & 7));
}
#define clear_bit_simple(nr,addr) \
(__builtin_constant_p((nr)) ? \
__constant_clear_bit((nr),(addr)) : \
__clear_bit((nr),(addr)) )
/*
* fast, non-SMP change_bit routine
*/
static inline void __change_bit(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
asm volatile(
" xc 0(1,%1),0(%2)"
: "=m" (*(char *) addr) : "a" (addr),
"a" (_oi_bitmap + (nr & 7)), "m" (*(char *) addr) : "cc" );
}
static inline void
__constant_change_bit(const unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
addr = ((unsigned long) ptr) + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
*(unsigned char *) addr ^= 1 << (nr & 7);
}
#define change_bit_simple(nr,addr) \
(__builtin_constant_p((nr)) ? \
__constant_change_bit((nr),(addr)) : \
__change_bit((nr),(addr)) )
/*
* fast, non-SMP test_and_set_bit routine
*/
static inline int
test_and_set_bit_simple(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
unsigned char ch;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
ch = *(unsigned char *) addr;
asm volatile(
" oc 0(1,%1),0(%2)"
: "=m" (*(char *) addr)
: "a" (addr), "a" (_oi_bitmap + (nr & 7)),
"m" (*(char *) addr) : "cc", "memory");
return (ch >> (nr & 7)) & 1;
}
#define __test_and_set_bit(X,Y) test_and_set_bit_simple(X,Y)
/*
* fast, non-SMP test_and_clear_bit routine
*/
static inline int
test_and_clear_bit_simple(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
unsigned char ch;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
ch = *(unsigned char *) addr;
asm volatile(
" nc 0(1,%1),0(%2)"
: "=m" (*(char *) addr)
: "a" (addr), "a" (_ni_bitmap + (nr & 7)),
"m" (*(char *) addr) : "cc", "memory");
return (ch >> (nr & 7)) & 1;
}
#define __test_and_clear_bit(X,Y) test_and_clear_bit_simple(X,Y)
/*
* fast, non-SMP test_and_change_bit routine
*/
static inline int
test_and_change_bit_simple(unsigned long nr, volatile unsigned long *ptr)
{
unsigned long addr;
unsigned char ch;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
ch = *(unsigned char *) addr;
asm volatile(
" xc 0(1,%1),0(%2)"
: "=m" (*(char *) addr)
: "a" (addr), "a" (_oi_bitmap + (nr & 7)),
"m" (*(char *) addr) : "cc", "memory");
return (ch >> (nr & 7)) & 1;
}
#define __test_and_change_bit(X,Y) test_and_change_bit_simple(X,Y)
#ifdef CONFIG_SMP
#define set_bit set_bit_cs
#define clear_bit clear_bit_cs
#define change_bit change_bit_cs
#define test_and_set_bit test_and_set_bit_cs
#define test_and_clear_bit test_and_clear_bit_cs
#define test_and_change_bit test_and_change_bit_cs
#else
#define set_bit set_bit_simple
#define clear_bit clear_bit_simple
#define change_bit change_bit_simple
#define test_and_set_bit test_and_set_bit_simple
#define test_and_clear_bit test_and_clear_bit_simple
#define test_and_change_bit test_and_change_bit_simple
#endif
/*
* This routine doesn't need to be atomic.
*/
static inline int __test_bit(unsigned long nr, const volatile unsigned long *ptr)
{
unsigned long addr;
unsigned char ch;
addr = (unsigned long) ptr + ((nr ^ (__BITOPS_WORDSIZE - 8)) >> 3);
ch = *(volatile unsigned char *) addr;
return (ch >> (nr & 7)) & 1;
}
static inline int
__constant_test_bit(unsigned long nr, const volatile unsigned long *addr) {
return (((volatile char *) addr)
[(nr^(__BITOPS_WORDSIZE-8))>>3] & (1<<(nr&7))) != 0;
}
#define test_bit(nr,addr) \
(__builtin_constant_p((nr)) ? \
__constant_test_bit((nr),(addr)) : \
__test_bit((nr),(addr)) )
/*
* Optimized find bit helper functions.
*/
/**
* __ffz_word_loop - find byte offset of first long != -1UL
* @addr: pointer to array of unsigned long
* @size: size of the array in bits
*/
static inline unsigned long __ffz_word_loop(const unsigned long *addr,
unsigned long size)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long bytes = 0;
asm volatile(
#ifndef __s390x__
" ahi %1,-1\n"
" sra %1,5\n"
" jz 1f\n"
"0: c %2,0(%0,%3)\n"
" jne 1f\n"
" la %0,4(%0)\n"
" brct %1,0b\n"
"1:\n"
#else
" aghi %1,-1\n"
" srag %1,%1,6\n"
" jz 1f\n"
"0: cg %2,0(%0,%3)\n"
" jne 1f\n"
" la %0,8(%0)\n"
" brct %1,0b\n"
"1:\n"
#endif
: "+&a" (bytes), "+&d" (size)
: "d" (-1UL), "a" (addr), "m" (*(addrtype *) addr)
: "cc" );
return bytes;
}
/**
* __ffs_word_loop - find byte offset of first long != 0UL
* @addr: pointer to array of unsigned long
* @size: size of the array in bits
*/
static inline unsigned long __ffs_word_loop(const unsigned long *addr,
unsigned long size)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long bytes = 0;
asm volatile(
#ifndef __s390x__
" ahi %1,-1\n"
" sra %1,5\n"
" jz 1f\n"
"0: c %2,0(%0,%3)\n"
" jne 1f\n"
" la %0,4(%0)\n"
" brct %1,0b\n"
"1:\n"
#else
" aghi %1,-1\n"
" srag %1,%1,6\n"
" jz 1f\n"
"0: cg %2,0(%0,%3)\n"
" jne 1f\n"
" la %0,8(%0)\n"
" brct %1,0b\n"
"1:\n"
#endif
: "+&a" (bytes), "+&a" (size)
: "d" (0UL), "a" (addr), "m" (*(addrtype *) addr)
: "cc" );
return bytes;
}
/**
* __ffz_word - add number of the first unset bit
* @nr: base value the bit number is added to
* @word: the word that is searched for unset bits
*/
static inline unsigned long __ffz_word(unsigned long nr, unsigned long word)
{
#ifdef __s390x__
if (likely((word & 0xffffffff) == 0xffffffff)) {
word >>= 32;
nr += 32;
}
#endif
if (likely((word & 0xffff) == 0xffff)) {
word >>= 16;
nr += 16;
}
if (likely((word & 0xff) == 0xff)) {
word >>= 8;
nr += 8;
}
return nr + _zb_findmap[(unsigned char) word];
}
/**
* __ffs_word - add number of the first set bit
* @nr: base value the bit number is added to
* @word: the word that is searched for set bits
*/
static inline unsigned long __ffs_word(unsigned long nr, unsigned long word)
{
#ifdef __s390x__
if (likely((word & 0xffffffff) == 0)) {
word >>= 32;
nr += 32;
}
#endif
if (likely((word & 0xffff) == 0)) {
word >>= 16;
nr += 16;
}
if (likely((word & 0xff) == 0)) {
word >>= 8;
nr += 8;
}
return nr + _sb_findmap[(unsigned char) word];
}
/**
* __load_ulong_be - load big endian unsigned long
* @p: pointer to array of unsigned long
* @offset: byte offset of source value in the array
*/
static inline unsigned long __load_ulong_be(const unsigned long *p,
unsigned long offset)
{
p = (unsigned long *)((unsigned long) p + offset);
return *p;
}
/**
* __load_ulong_le - load little endian unsigned long
* @p: pointer to array of unsigned long
* @offset: byte offset of source value in the array
*/
static inline unsigned long __load_ulong_le(const unsigned long *p,
unsigned long offset)
{
unsigned long word;
p = (unsigned long *)((unsigned long) p + offset);
#ifndef __s390x__
asm volatile(
" ic %0,0(%1)\n"
" icm %0,2,1(%1)\n"
" icm %0,4,2(%1)\n"
" icm %0,8,3(%1)"
: "=&d" (word) : "a" (p), "m" (*p) : "cc");
#else
asm volatile(
" lrvg %0,%1"
: "=d" (word) : "m" (*p) );
#endif
return word;
}
/*
* The various find bit functions.
*/
/*
* ffz - find first zero in word.
* @word: The word to search
*
* Undefined if no zero exists, so code should check against ~0UL first.
*/
static inline unsigned long ffz(unsigned long word)
{
return __ffz_word(0, word);
}
/**
* __ffs - find first bit in word.
* @word: The word to search
*
* Undefined if no bit exists, so code should check against 0 first.
*/
static inline unsigned long __ffs (unsigned long word)
{
return __ffs_word(0, word);
}
/**
* ffs - find first bit set
* @x: the word to search
*
* This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
static inline int ffs(int x)
{
if (!x)
return 0;
return __ffs_word(1, x);
}
/**
* find_first_zero_bit - find the first zero bit in a memory region
* @addr: The address to start the search at
* @size: The maximum size to search
*
* Returns the bit-number of the first zero bit, not the number of the byte
* containing a bit.
*/
static inline unsigned long find_first_zero_bit(const unsigned long *addr,
unsigned long size)
{
unsigned long bytes, bits;
if (!size)
return 0;
bytes = __ffz_word_loop(addr, size);
bits = __ffz_word(bytes*8, __load_ulong_be(addr, bytes));
return (bits < size) ? bits : size;
}
/**
* find_first_bit - find the first set bit in a memory region
* @addr: The address to start the search at
* @size: The maximum size to search
*
* Returns the bit-number of the first set bit, not the number of the byte
* containing a bit.
*/
static inline unsigned long find_first_bit(const unsigned long * addr,
unsigned long size)
{
unsigned long bytes, bits;
if (!size)
return 0;
bytes = __ffs_word_loop(addr, size);
bits = __ffs_word(bytes*8, __load_ulong_be(addr, bytes));
return (bits < size) ? bits : size;
}
/**
* find_next_zero_bit - find the first zero bit in a memory region
* @addr: The address to base the search on
* @offset: The bitnumber to start searching at
* @size: The maximum size to search
*/
static inline int find_next_zero_bit (const unsigned long * addr,
unsigned long size,
unsigned long offset)
{
const unsigned long *p;
unsigned long bit, set;
if (offset >= size)
return size;
bit = offset & (__BITOPS_WORDSIZE - 1);
offset -= bit;
size -= offset;
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
/*
* __ffz_word returns __BITOPS_WORDSIZE
* if no zero bit is present in the word.
*/
set = __ffz_word(0, *p >> bit) + bit;
if (set >= size)
return size + offset;
if (set < __BITOPS_WORDSIZE)
return set + offset;
offset += __BITOPS_WORDSIZE;
size -= __BITOPS_WORDSIZE;
p++;
}
return offset + find_first_zero_bit(p, size);
}
/**
* find_next_bit - find the first set bit in a memory region
* @addr: The address to base the search on
* @offset: The bitnumber to start searching at
* @size: The maximum size to search
*/
static inline int find_next_bit (const unsigned long * addr,
unsigned long size,
unsigned long offset)
{
const unsigned long *p;
unsigned long bit, set;
if (offset >= size)
return size;
bit = offset & (__BITOPS_WORDSIZE - 1);
offset -= bit;
size -= offset;
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
/*
* __ffs_word returns __BITOPS_WORDSIZE
* if no one bit is present in the word.
*/
set = __ffs_word(0, *p & (~0UL << bit));
if (set >= size)
return size + offset;
if (set < __BITOPS_WORDSIZE)
return set + offset;
offset += __BITOPS_WORDSIZE;
size -= __BITOPS_WORDSIZE;
p++;
}
return offset + find_first_bit(p, size);
}
/*
* Every architecture must define this function. It's the fastest
* way of searching a 140-bit bitmap where the first 100 bits are
* unlikely to be set. It's guaranteed that at least one of the 140
* bits is cleared.
*/
static inline int sched_find_first_bit(unsigned long *b)
{
return find_first_bit(b, 140);
}
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
/*
* ATTENTION: intel byte ordering convention for ext2 and minix !!
* bit 0 is the LSB of addr; bit 31 is the MSB of addr;
* bit 32 is the LSB of (addr+4).
* That combined with the little endian byte order of Intel gives the
* following bit order in memory:
* 07 06 05 04 03 02 01 00 15 14 13 12 11 10 09 08 \
* 23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24
*/
#define ext2_set_bit(nr, addr) \
__test_and_set_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
#define ext2_set_bit_atomic(lock, nr, addr) \
test_and_set_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
#define ext2_clear_bit(nr, addr) \
__test_and_clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
#define ext2_clear_bit_atomic(lock, nr, addr) \
test_and_clear_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
#define ext2_test_bit(nr, addr) \
test_bit((nr)^(__BITOPS_WORDSIZE - 8), (unsigned long *)addr)
static inline int ext2_find_first_zero_bit(void *vaddr, unsigned int size)
{
unsigned long bytes, bits;
if (!size)
return 0;
bytes = __ffz_word_loop(vaddr, size);
bits = __ffz_word(bytes*8, __load_ulong_le(vaddr, bytes));
return (bits < size) ? bits : size;
}
static inline int ext2_find_next_zero_bit(void *vaddr, unsigned long size,
unsigned long offset)
{
unsigned long *addr = vaddr, *p;
unsigned long bit, set;
if (offset >= size)
return size;
bit = offset & (__BITOPS_WORDSIZE - 1);
offset -= bit;
size -= offset;
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
/*
* s390 version of ffz returns __BITOPS_WORDSIZE
* if no zero bit is present in the word.
*/
set = ffz(__load_ulong_le(p, 0) >> bit) + bit;
if (set >= size)
return size + offset;
if (set < __BITOPS_WORDSIZE)
return set + offset;
offset += __BITOPS_WORDSIZE;
size -= __BITOPS_WORDSIZE;
p++;
}
return offset + ext2_find_first_zero_bit(p, size);
}
static inline unsigned long ext2_find_first_bit(void *vaddr,
unsigned long size)
{
unsigned long bytes, bits;
if (!size)
return 0;
bytes = __ffs_word_loop(vaddr, size);
bits = __ffs_word(bytes*8, __load_ulong_le(vaddr, bytes));
return (bits < size) ? bits : size;
}
static inline int ext2_find_next_bit(void *vaddr, unsigned long size,
unsigned long offset)
{
unsigned long *addr = vaddr, *p;
unsigned long bit, set;
if (offset >= size)
return size;
bit = offset & (__BITOPS_WORDSIZE - 1);
offset -= bit;
size -= offset;
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
/*
* s390 version of ffz returns __BITOPS_WORDSIZE
* if no zero bit is present in the word.
*/
set = ffs(__load_ulong_le(p, 0) >> bit) + bit;
if (set >= size)
return size + offset;
if (set < __BITOPS_WORDSIZE)
return set + offset;
offset += __BITOPS_WORDSIZE;
size -= __BITOPS_WORDSIZE;
p++;
}
return offset + ext2_find_first_bit(p, size);
}
#include <asm-generic/bitops/minix.h>
#endif /* __KERNEL__ */
#endif /* _S390_BITOPS_H */
Reference in a new issue View git blame Copy permalink