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s390/bitops: use generic find bit functions / reimplement _left variant 

Just like all other architectures we should use out-of-line find bit
operations, since the inline variant bloat the size of the kernel image.
And also like all other architecures we should only supply optimized
variants of the __ffs, ffs, etc. primitives.

Therefore this patch removes the inlined s390 find bit functions and uses
the generic out-of-line variants instead.

The optimization of the primitives follows with the next patch.

With this patch also the functions find_first_bit_left() and
find_next_bit_left() have been reimplemented, since logically, they are
nothing else but a find_first_bit()/find_next_bit() implementation that
use an inverted __fls() instead of __ffs().
Also the restriction that these functions only work on machines which
support the "flogr" instruction is gone now.

This reduces the size of the kernel image (defconfig, -march=z9-109)
by 144,482 bytes.
Alone the size of the function build_sched_domains() gets reduced from
7 KB to 3,5 KB.

We also git rid of unused functions like find_first_bit_le()...

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2013-09-18 11:45:36 +02:00 committed by Martin Schwidefsky
parent 8e6a828566
commit 746479cdcb
6 changed files with 126 additions and 604 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/s390/Kconfig
View File

@ -99,6 +99,7 @@ config S390
select CLONE_BACKWARDS2
select GENERIC_CLOCKEVENTS
select GENERIC_CPU_DEVICES if !SMP
select GENERIC_FIND_FIRST_BIT
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL_OLD
select HAVE_ALIGNED_STRUCT_PAGE if SLUB

600
arch/s390/include/asm/bitops.h
View File

@ -1,10 +1,40 @@
/*
* S390 version
* Copyright IBM Corp. 1999
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
* Copyright IBM Corp. 1999,2013
*
* Derived from "include/asm-i386/bitops.h"
* Copyright (C) 1992, Linus Torvalds
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
*
* The description below was taken in large parts from the powerpc
* bitops header file:
* Within a word, bits are numbered LSB first. Lot's of places make
* this assumption by directly testing bits with (val & (1<<nr)).
* This can cause confusion for large (> 1 word) bitmaps on a
* big-endian system because, unlike little endian, the number of each
* bit depends on the word size.
*
* The bitop functions are defined to work on unsigned longs, so for an
* s390x system the bits end up numbered:
* |63..............0|127............64|191...........128|255...........196|
* and on s390:
* |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224|
*
* There are a few little-endian macros used mostly for filesystem
* bitmaps, these work on similar bit arrays layouts, but
* byte-oriented:
* |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
*
* The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
* number field needs to be reversed compared to the big-endian bit
* fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
*
* We also have special functions which work with an MSB0 encoding:
* on an s390x system the bits are numbered:
* |0..............63|64............127|128...........191|192...........255|
* and on s390:
* |0.....31|31....63|64....95|96...127|128..159|160..191|192..223|224..255|
*
* The main difference is that bit 0-63 (64b) or 0-31 (32b) in the bit
* number field needs to be reversed compared to the LSB0 encoded bit
* fields. This can be achieved by XOR with 0x3f (64b) or 0x1f (32b).
*
*/
@ -18,46 +48,6 @@
#include <linux/typecheck.h>
#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.c */
extern const char _zb_findmap[];
extern const char _sb_findmap[];
#ifndef CONFIG_64BIT
#define __BITOPS_OR "or"
@ -310,522 +300,24 @@ static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
}
/*
* Optimized find bit helper functions.
* ATTENTION:
* find_first_bit_left() and find_next_bit_left() use MSB0 encoding.
*/
unsigned long find_first_bit_left(const unsigned long *addr, unsigned long size);
unsigned long find_next_bit_left(const unsigned long *addr, unsigned long size,
unsigned long offset);
/**
* __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 CONFIG_64BIT
" 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 CONFIG_64BIT
" 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 CONFIG_64BIT
if ((word & 0xffffffff) == 0xffffffff) {
word >>= 32;
nr += 32;
}
#endif
if ((word & 0xffff) == 0xffff) {
word >>= 16;
nr += 16;
}
if ((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 CONFIG_64BIT
if ((word & 0xffffffff) == 0) {
word >>= 32;
nr += 32;
}
#endif
if ((word & 0xffff) == 0) {
word >>= 16;
nr += 16;
}
if ((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 CONFIG_64BIT
asm volatile(
" ic %0,%O1(%R1)\n"
" icm %0,2,%O1+1(%R1)\n"
" icm %0,4,%O1+2(%R1)\n"
" icm %0,8,%O1+3(%R1)"
: "=&d" (word) : "Q" (*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;
}
#define find_first_zero_bit find_first_zero_bit
/**
* 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;
}
#define find_first_bit find_first_bit
/*
* Big endian variant whichs starts bit counting from left using
* the flogr (find leftmost one) instruction.
*/
static inline unsigned long __flo_word(unsigned long nr, unsigned long val)
{
register unsigned long bit asm("2") = val;
register unsigned long out asm("3");
asm volatile (
" .insn rre,0xb9830000,%[bit],%[bit]\n"
: [bit] "+d" (bit), [out] "=d" (out) : : "cc");
return nr + bit;
}
/*
* 64 bit special left bitops format:
* order in memory:
* 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
* 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
* 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
* 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
* after that follows the next long with bit numbers
* 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
* 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
* 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
* 70 71 72 73 74 75 76 77 78 79 7a 7b 7c 7d 7e 7f
* The reason for this bit ordering is the fact that
* the hardware sets bits in a bitmap starting at bit 0
* and we don't want to scan the bitmap from the 'wrong
* end'.
*/
static inline unsigned long find_first_bit_left(const unsigned long *addr,
unsigned long size)
{
unsigned long bytes, bits;
if (!size)
return 0;
bytes = __ffs_word_loop(addr, size);
bits = __flo_word(bytes * 8, __load_ulong_be(addr, bytes));
return (bits < size) ? bits : size;
}
static inline int find_next_bit_left(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 & (BITS_PER_LONG - 1);
offset -= bit;
size -= offset;
p = addr + offset / BITS_PER_LONG;
if (bit) {
set = __flo_word(0, *p & (~0UL >> bit));
if (set >= size)
return size + offset;
if (set < BITS_PER_LONG)
return set + offset;
offset += BITS_PER_LONG;
size -= BITS_PER_LONG;
p++;
}
return offset + find_first_bit_left(p, size);
}
#define for_each_set_bit_left(bit, addr, size) \
for ((bit) = find_first_bit_left((addr), (size)); \
(bit) < (size); \
(bit) = find_next_bit_left((addr), (size), (bit) + 1))
/* same as for_each_set_bit() but use bit as value to start with */
#define for_each_set_bit_left_cont(bit, addr, size) \
for ((bit) = find_next_bit_left((addr), (size), (bit)); \
(bit) < (size); \
(bit) = find_next_bit_left((addr), (size), (bit) + 1))
/**
* 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 & (BITS_PER_LONG - 1);
offset -= bit;
size -= offset;
p = addr + offset / BITS_PER_LONG;
if (bit) {
/*
* __ffz_word returns BITS_PER_LONG
* if no zero bit is present in the word.
*/
set = __ffz_word(bit, *p >> bit);
if (set >= size)
return size + offset;
if (set < BITS_PER_LONG)
return set + offset;
offset += BITS_PER_LONG;
size -= BITS_PER_LONG;
p++;
}
return offset + find_first_zero_bit(p, size);
}
#define find_next_zero_bit find_next_zero_bit
/**
* 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 & (BITS_PER_LONG - 1);
offset -= bit;
size -= offset;
p = addr + offset / BITS_PER_LONG;
if (bit) {
/*
* __ffs_word returns BITS_PER_LONG
* if no one bit is present in the word.
*/
set = __ffs_word(0, *p & (~0UL << bit));
if (set >= size)
return size + offset;
if (set < BITS_PER_LONG)
return set + offset;
offset += BITS_PER_LONG;
size -= BITS_PER_LONG;
p++;
}
return offset + find_first_bit(p, size);
}
#define find_next_bit find_next_bit
/*
* 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/__ffs.h>
#include <asm-generic/bitops/ffs.h>
#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/find.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
*/
static inline int find_first_zero_bit_le(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;
}
#define find_first_zero_bit_le find_first_zero_bit_le
static inline int find_next_zero_bit_le(void *vaddr, unsigned long size,
unsigned long offset)
{
unsigned long *addr = vaddr, *p;
unsigned long bit, set;
if (offset >= size)
return size;
bit = offset & (BITS_PER_LONG - 1);
offset -= bit;
size -= offset;
p = addr + offset / BITS_PER_LONG;
if (bit) {
/*
* s390 version of ffz returns BITS_PER_LONG
* if no zero bit is present in the word.
*/
set = __ffz_word(bit, __load_ulong_le(p, 0) >> bit);
if (set >= size)
return size + offset;
if (set < BITS_PER_LONG)
return set + offset;
offset += BITS_PER_LONG;
size -= BITS_PER_LONG;
p++;
}
return offset + find_first_zero_bit_le(p, size);
}
#define find_next_zero_bit_le find_next_zero_bit_le
static inline unsigned long find_first_bit_le(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;
}
#define find_first_bit_le find_first_bit_le
static inline int find_next_bit_le(void *vaddr, unsigned long size,
unsigned long offset)
{
unsigned long *addr = vaddr, *p;
unsigned long bit, set;
if (offset >= size)
return size;
bit = offset & (BITS_PER_LONG - 1);
offset -= bit;
size -= offset;
p = addr + offset / BITS_PER_LONG;
if (bit) {
/*
* s390 version of ffz returns BITS_PER_LONG
* if no zero bit is present in the word.
*/
set = __ffs_word(0, __load_ulong_le(p, 0) & (~0UL << bit));
if (set >= size)
return size + offset;
if (set < BITS_PER_LONG)
return set + offset;
offset += BITS_PER_LONG;
size -= BITS_PER_LONG;
p++;
}
return offset + find_first_bit_le(p, size);
}
#define find_next_bit_le find_next_bit_le
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic-setbit.h>
#endif /* _S390_BITOPS_H */

2
arch/s390/kernel/Makefile
View File

@ -28,7 +28,7 @@ CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"'
CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w
obj-y := bitmap.o traps.o time.o process.o base.o early.o setup.o vtime.o
obj-y := traps.o time.o process.o base.o early.o setup.o vtime.o
obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o
obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o

48
arch/s390/kernel/bitmap.c
View File

@ -1,48 +0,0 @@
/*
* Bitmaps for set_bit, clear_bit, test_and_set_bit, ...
* See include/asm/{bitops.h|posix_types.h} for details
*
* Copyright IBM Corp. 1999, 2009
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
*/
#include <linux/bitops.h>
#include <linux/module.h>
const char _zb_findmap[] = {
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,6,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,7,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,6,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,
0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,8 };
EXPORT_SYMBOL(_zb_findmap);
const char _sb_findmap[] = {
8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0 };
EXPORT_SYMBOL(_sb_findmap);

2
arch/s390/lib/Makefile
View File

@ -2,7 +2,7 @@
# Makefile for s390-specific library files..
#
lib-y += delay.o string.o uaccess_std.o uaccess_pt.o
lib-y += delay.o string.o uaccess_std.o uaccess_pt.o find.o
obj-$(CONFIG_32BIT) += div64.o qrnnd.o ucmpdi2.o mem32.o
obj-$(CONFIG_64BIT) += mem64.o
lib-$(CONFIG_64BIT) += uaccess_mvcos.o

77
arch/s390/lib/find.c Normal file
View File

@ -0,0 +1,77 @@
/*
* MSB0 numbered special bitops handling.
*
* On s390x the bits are numbered:
* |0..............63|64............127|128...........191|192...........255|
* and on s390:
* |0.....31|31....63|64....95|96...127|128..159|160..191|192..223|224..255|
*
* The reason for this bit numbering is the fact that the hardware sets bits
* in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap
* from the 'wrong end'.
*/
#include <linux/compiler.h>
#include <linux/bitops.h>
#include <linux/export.h>
unsigned long find_first_bit_left(const unsigned long *addr, unsigned long size)
{
const unsigned long *p = addr;
unsigned long result = 0;
unsigned long tmp;
while (size & ~(BITS_PER_LONG - 1)) {
if ((tmp = *(p++)))
goto found;
result += BITS_PER_LONG;
size -= BITS_PER_LONG;
}
if (!size)
return result;
tmp = (*p) & (~0UL << (BITS_PER_LONG - size));
if (!tmp) /* Are any bits set? */
return result + size; /* Nope. */
found:
return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
}
EXPORT_SYMBOL(find_first_bit_left);
unsigned long find_next_bit_left(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
const unsigned long *p = addr + (offset / BITS_PER_LONG);
unsigned long result = offset & ~(BITS_PER_LONG - 1);
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset %= BITS_PER_LONG;
if (offset) {
tmp = *(p++);
tmp &= (~0UL >> 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;
result += BITS_PER_LONG;
size -= BITS_PER_LONG;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp &= (~0UL << (BITS_PER_LONG - size));
if (!tmp) /* Are any bits set? */
return result + size; /* Nope. */
found_middle:
return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
}
EXPORT_SYMBOL(find_next_bit_left);