Commit 0abbf05c authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] Cleanup & optimize bitops.



The bitops header is now a bit shorter and easier to understand since
it uses less inline assembly. It requires some tricks to persuade the
compiler to generate decent code. The ffz/ffs functions now use the
_zb_findmap/_sb_findmap table as well.
With this cleanup the new bitops for ext4 can be implemented with a
few lines, instead of another large inline assembly.
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent b6b40c53
......@@ -440,242 +440,256 @@ __constant_test_bit(unsigned long nr, const volatile unsigned long *addr) {
__test_bit((nr),(addr)) )
/*
* ffz = Find First Zero in word. Undefined if no zero exists,
* so code should check against ~0UL first..
* Optimized find bit helper functions.
*/
static inline unsigned long ffz(unsigned long word)
/**
* __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 %1,31\n"
" srl %1,5\n"
"0: c %2,0(%0,%3)\n"
" jne 1f\n"
" la %0,4(%0)\n"
" brct %1,0b\n"
"1:\n"
#else
" aghi %1,63\n"
" srlg %1,%1,6\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)
{
unsigned long bit = 0;
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long bytes = 0;
asm volatile(
#ifndef __s390x__
" ahi %1,31\n"
" srl %1,5\n"
"0: c %2,0(%0,%3)\n"
" jne 1f\n"
" la %0,4(%0)\n"
" brct %1,0b\n"
"1:\n"
#else
" aghi %1,63\n"
" srlg %1,%1,6\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;
bit += 32;
nr += 32;
}
#endif
if (likely((word & 0xffff) == 0xffff)) {
word >>= 16;
bit += 16;
nr += 16;
}
if (likely((word & 0xff) == 0xff)) {
word >>= 8;
bit += 8;
nr += 8;
}
return bit + _zb_findmap[word & 0xff];
return nr + _zb_findmap[(unsigned char) word];
}
/*
* __ffs = find first bit in word. Undefined if no bit exists,
* so code should check against 0UL first..
/**
* __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 (unsigned long word)
static inline unsigned long __ffs_word(unsigned long nr, unsigned long word)
{
unsigned long bit = 0;
#ifdef __s390x__
if (likely((word & 0xffffffff) == 0)) {
word >>= 32;
bit += 32;
nr += 32;
}
#endif
if (likely((word & 0xffff) == 0)) {
word >>= 16;
bit += 16;
nr += 16;
}
if (likely((word & 0xff) == 0)) {
word >>= 8;
bit += 8;
nr += 8;
}
return bit + _sb_findmap[word & 0xff];
return nr + _sb_findmap[(unsigned char) word];
}
/*
* Find-bit routines..
*/
#ifndef __s390x__
/**
* __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;
}
static inline int
find_first_zero_bit(const unsigned long * addr, unsigned long size)
/**
* __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)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long cmp, count;
unsigned int res;
unsigned long word;
if (!size)
return 0;
p = (unsigned long *)((unsigned long) p + offset);
#ifndef __s390x__
asm volatile(
" lhi %1,-1\n"
" lr %2,%3\n"
" slr %0,%0\n"
" ahi %2,31\n"
" srl %2,5\n"
"0: c %1,0(%0,%4)\n"
" jne 1f\n"
" la %0,4(%0)\n"
" brct %2,0b\n"
" lr %0,%3\n"
" j 4f\n"
"1: l %2,0(%0,%4)\n"
" sll %0,3\n"
" lhi %1,0xff\n"
" tml %2,0xffff\n"
" jno 2f\n"
" ahi %0,16\n"
" srl %2,16\n"
"2: tml %2,0x00ff\n"
" jno 3f\n"
" ahi %0,8\n"
" srl %2,8\n"
"3: nr %2,%1\n"
" ic %2,0(%2,%5)\n"
" alr %0,%2\n"
"4:"
: "=&a" (res), "=&d" (cmp), "=&a" (count)
: "a" (size), "a" (addr), "a" (&_zb_findmap),
"m" (*(addrtype *) addr) : "cc");
return (res < size) ? res : size;
" 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;
}
static inline int
find_first_bit(const unsigned long * addr, unsigned long size)
/*
* 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)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long cmp, count;
unsigned int res;
return __ffz_word(0, word);
}
if (!size)
return 0;
asm volatile(
" slr %1,%1\n"
" lr %2,%3\n"
" slr %0,%0\n"
" ahi %2,31\n"
" srl %2,5\n"
"0: c %1,0(%0,%4)\n"
" jne 1f\n"
" la %0,4(%0)\n"
" brct %2,0b\n"
" lr %0,%3\n"
" j 4f\n"
"1: l %2,0(%0,%4)\n"
" sll %0,3\n"
" lhi %1,0xff\n"
" tml %2,0xffff\n"
" jnz 2f\n"
" ahi %0,16\n"
" srl %2,16\n"
"2: tml %2,0x00ff\n"
" jnz 3f\n"
" ahi %0,8\n"
" srl %2,8\n"
"3: nr %2,%1\n"
" ic %2,0(%2,%5)\n"
" alr %0,%2\n"
"4:"
: "=&a" (res), "=&d" (cmp), "=&a" (count)
: "a" (size), "a" (addr), "a" (&_sb_findmap),
"m" (*(addrtype *) addr) : "cc");
return (res < size) ? res : size;
/**
* __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);
}
#else /* __s390x__ */
/**
* 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);
}
static inline unsigned long
find_first_zero_bit(const unsigned long * addr, unsigned long size)
/**
* 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)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long res, cmp, count;
unsigned long bytes, bits;
if (!size)
return 0;
asm volatile(
" lghi %1,-1\n"
" lgr %2,%3\n"
" slgr %0,%0\n"
" aghi %2,63\n"
" srlg %2,%2,6\n"
"0: cg %1,0(%0,%4)\n"
" jne 1f\n"
" la %0,8(%0)\n"
" brct %2,0b\n"
" lgr %0,%3\n"
" j 5f\n"
"1: lg %2,0(%0,%4)\n"
" sllg %0,%0,3\n"
" clr %2,%1\n"
" jne 2f\n"
" aghi %0,32\n"
" srlg %2,%2,32\n"
"2: lghi %1,0xff\n"
" tmll %2,0xffff\n"
" jno 3f\n"
" aghi %0,16\n"
" srl %2,16\n"
"3: tmll %2,0x00ff\n"
" jno 4f\n"
" aghi %0,8\n"
" srl %2,8\n"
"4: ngr %2,%1\n"
" ic %2,0(%2,%5)\n"
" algr %0,%2\n"
"5:"
: "=&a" (res), "=&d" (cmp), "=&a" (count)
: "a" (size), "a" (addr), "a" (&_zb_findmap),
"m" (*(addrtype *) addr) : "cc");
return (res < size) ? res : size;
}
static inline unsigned long
find_first_bit(const unsigned long * addr, unsigned long size)
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)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long res, cmp, count;
unsigned long bytes, bits;
if (!size)
return 0;
asm volatile(
" slgr %1,%1\n"
" lgr %2,%3\n"
" slgr %0,%0\n"
" aghi %2,63\n"
" srlg %2,%2,6\n"
"0: cg %1,0(%0,%4)\n"
" jne 1f\n"
" aghi %0,8\n"
" brct %2,0b\n"
" lgr %0,%3\n"
" j 5f\n"
"1: lg %2,0(%0,%4)\n"
" sllg %0,%0,3\n"
" clr %2,%1\n"
" jne 2f\n"
" aghi %0,32\n"
" srlg %2,%2,32\n"
"2: lghi %1,0xff\n"
" tmll %2,0xffff\n"
" jnz 3f\n"
" aghi %0,16\n"
" srl %2,16\n"
"3: tmll %2,0x00ff\n"
" jnz 4f\n"
" aghi %0,8\n"
" srl %2,8\n"
"4: ngr %2,%1\n"
" ic %2,0(%2,%5)\n"
" algr %0,%2\n"
"5:"
: "=&a" (res), "=&d" (cmp), "=&a" (count)
: "a" (size), "a" (addr), "a" (&_sb_findmap),
"m" (*(addrtype *) addr) : "cc");
return (res < size) ? res : size;
bytes = __ffs_word_loop(addr, size);
bits = __ffs_word(bytes*8, __load_ulong_be(addr, bytes));
return (bits < size) ? bits : size;
}
#endif /* __s390x__ */
static inline int
find_next_zero_bit (const unsigned long * addr, unsigned long size,
unsigned long offset)
/**
* 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;
......@@ -688,10 +702,10 @@ find_next_zero_bit (const unsigned long * addr, unsigned long size,
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
/*
* s390 version of ffz returns __BITOPS_WORDSIZE
* __ffz_word returns __BITOPS_WORDSIZE
* if no zero bit is present in the word.
*/
set = ffz(*p >> bit) + bit;
set = __ffz_word(0, *p >> bit) + bit;
if (set >= size)
return size + offset;
if (set < __BITOPS_WORDSIZE)
......@@ -703,9 +717,15 @@ find_next_zero_bit (const unsigned long * addr, unsigned long size,
return offset + find_first_zero_bit(p, size);
}
static inline int
find_next_bit (const unsigned long * addr, unsigned long size,
unsigned long offset)
/**
* 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;
......@@ -718,10 +738,10 @@ find_next_bit (const unsigned long * addr, unsigned long size,
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
/*
* s390 version of __ffs returns __BITOPS_WORDSIZE
* __ffs_word returns __BITOPS_WORDSIZE
* if no one bit is present in the word.
*/
set = __ffs(*p & (~0UL << bit));
set = __ffs_word(0, *p & (~0UL << bit));
if (set >= size)
return size + offset;
if (set < __BITOPS_WORDSIZE)
......@@ -744,8 +764,6 @@ static inline int sched_find_first_bit(unsigned long *b)
return find_first_bit(b, 140);
}
#include <asm-generic/bitops/ffs.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/fls64.h>
......@@ -775,105 +793,22 @@ static inline int sched_find_first_bit(unsigned long *b)
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_le_bit((unsigned long *)(addr), (size), (off))
#ifndef __s390x__
static inline int
ext2_find_first_zero_bit(void *vaddr, unsigned int size)
static inline int ext2_find_first_zero_bit(void *vaddr, unsigned int size)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long cmp, count;
unsigned int res;
unsigned long bytes, bits;
if (!size)
return 0;
asm volatile(
" lhi %1,-1\n"
" lr %2,%3\n"
" ahi %2,31\n"
" srl %2,5\n"
" slr %0,%0\n"
"0: cl %1,0(%0,%4)\n"
" jne 1f\n"
" ahi %0,4\n"
" brct %2,0b\n"
" lr %0,%3\n"
" j 4f\n"
"1: l %2,0(%0,%4)\n"
" sll %0,3\n"
" ahi %0,24\n"
" lhi %1,0xff\n"
" tmh %2,0xffff\n"
" jo 2f\n"
" ahi %0,-16\n"
" srl %2,16\n"
"2: tml %2,0xff00\n"
" jo 3f\n"
" ahi %0,-8\n"
" srl %2,8\n"
"3: nr %2,%1\n"
" ic %2,0(%2,%5)\n"
" alr %0,%2\n"
"4:"
: "=&a" (res), "=&d" (cmp), "=&a" (count)
: "a" (size), "a" (vaddr), "a" (&_zb_findmap),
"m" (*(addrtype *) vaddr) : "cc");
return (res < size) ? res : size;
bytes = __ffz_word_loop(vaddr, size);
bits = __ffz_word(bytes*8, __load_ulong_le(vaddr, bytes));
return (bits < size) ? bits : size;
}
#else /* __s390x__ */
static inline unsigned long
ext2_find_first_zero_bit(void *vaddr, unsigned long size)
{
typedef struct { long _[__BITOPS_WORDS(size)]; } addrtype;
unsigned long res, cmp, count;
if (!size)
return 0;
asm volatile(
" lghi %1,-1\n"
" lgr %2,%3\n"
" aghi %2,63\n"
" srlg %2,%2,6\n"
" slgr %0,%0\n"
"0: clg %1,0(%0,%4)\n"
" jne 1f\n"
" aghi %0,8\n"
" brct %2,0b\n"
" lgr %0,%3\n"
" j 5f\n"
"1: cl %1,0(%0,%4)\n"
" jne 2f\n"
" aghi %0,4\n"
"2: l %2,0(%0,%4)\n"
" sllg %0,%0,3\n"
" aghi %0,24\n"
" lghi %1,0xff\n"
" tmlh %2,0xffff\n"
" jo 3f\n"
" aghi %0,-16\n"
" srl %2,16\n"
"3: tmll %2,0xff00\n"
" jo 4f\n"
" aghi %0,-8\n"
" srl %2,8\n"
"4: ngr %2,%1\n"
" ic %2,0(%2,%5)\n"
" algr %0,%2\n"
"5:"
: "=&a" (res), "=&d" (cmp), "=&a" (count)
: "a" (size), "a" (vaddr), "a" (&_zb_findmap),
"m" (*(addrtype *) vaddr) : "cc");
return (res < size) ? res : size;
}
#endif /* __s390x__ */
static inline int
ext2_find_next_zero_bit(void *vaddr, unsigned long size, unsigned long offset)
static inline int ext2_find_next_zero_bit(void *vaddr, unsigned long size,
unsigned long offset)
{
unsigned long *addr = vaddr, *p;
unsigned long word, bit, set;
unsigned long bit, set;
if (offset >= size)
return size;
......@@ -882,23 +817,11 @@ ext2_find_next_zero_bit(void *vaddr, unsigned long size, unsigned long offset)
size -= offset;
p = addr + offset / __BITOPS_WORDSIZE;
if (bit) {
#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)"
: "=&a" (word) : "a" (p), "m" (*p) : "cc");
#else
asm volatile(
" lrvg %0,%1"
: "=a" (word) : "m" (*p) );
#endif
/*
* s390 version of ffz returns __BITOPS_WORDSIZE
* if no zero bit is present in the word.