linux/arch/s390/include/asm/bitops.h

217 lines
5.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999,2013
*
* 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 the bits
* end up numbered:
* |63..............0|127............64|191...........128|255...........192|
*
* We also have special functions which work with an MSB0 encoding.
* The bits are numbered:
* |0..............63|64............127|128...........191|192...........255|
*
* The main difference is that bit 0-63 in the bit number field needs to be
* reversed compared to the LSB0 encoded bit fields. This can be achieved by
* XOR with 0x3f.
*
*/
#ifndef _S390_BITOPS_H
#define _S390_BITOPS_H
#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif
#include <linux/typecheck.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/asm.h>
#define arch___set_bit generic___set_bit
#define arch___clear_bit generic___clear_bit
#define arch___change_bit generic___change_bit
#define arch___test_and_set_bit generic___test_and_set_bit
#define arch___test_and_clear_bit generic___test_and_clear_bit
#define arch___test_and_change_bit generic___test_and_change_bit
#define arch_test_bit_acquire generic_test_bit_acquire
static __always_inline bool arch_test_bit(unsigned long nr, const volatile unsigned long *ptr)
{
#ifdef __HAVE_ASM_FLAG_OUTPUTS__
const volatile unsigned char *addr;
unsigned long mask;
int cc;
/*
* With CONFIG_PROFILE_ALL_BRANCHES enabled gcc fails to
* handle __builtin_constant_p() in some cases.
*/
if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && __builtin_constant_p(nr)) {
addr = (const volatile unsigned char *)ptr;
addr += (nr ^ (BITS_PER_LONG - BITS_PER_BYTE)) / BITS_PER_BYTE;
mask = 1UL << (nr & (BITS_PER_BYTE - 1));
asm volatile(
" tm %[addr],%[mask]\n"
: "=@cc" (cc)
: [addr] "Q" (*addr), [mask] "I" (mask)
);
return cc == 3;
}
#endif
return generic_test_bit(nr, ptr);
}
#include <asm-generic/bitops/atomic.h>
#include <asm-generic/bitops/non-instrumented-non-atomic.h>
#include <asm-generic/bitops/lock.h>
/*
* Functions which use MSB0 bit numbering.
* The bits are numbered:
* |0..............63|64............127|128...........191|192...........255|
*/
unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size);
unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
unsigned long offset);
#define for_each_set_bit_inv(bit, addr, size) \
for ((bit) = find_first_bit_inv((addr), (size)); \
(bit) < (size); \
(bit) = find_next_bit_inv((addr), (size), (bit) + 1))
static inline void set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
{
return set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
}
static inline void clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
{
return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
}
static inline bool test_and_clear_bit_inv(unsigned long nr,
volatile unsigned long *ptr)
{
return test_and_clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
}
static inline void __set_bit_inv(unsigned long nr, volatile unsigned long *ptr)
{
return __set_bit(nr ^ (BITS_PER_LONG - 1), ptr);
}
static inline void __clear_bit_inv(unsigned long nr, volatile unsigned long *ptr)
{
return __clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
}
static inline bool test_bit_inv(unsigned long nr,
const volatile unsigned long *ptr)
{
return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
}
#ifndef CONFIG_CC_HAS_BUILTIN_FFS
/**
* __flogr - find leftmost one
* @word - The word to search
*
* Returns the bit number of the most significant bit set,
* where the most significant bit has bit number 0.
* If no bit is set this function returns 64.
*/
static __always_inline __attribute_const__ unsigned long __flogr(unsigned long word)
{
unsigned long bit;
if (__builtin_constant_p(word)) {
bit = 0;
if (!word)
return 64;
if (!(word & 0xffffffff00000000UL)) {
word <<= 32;
bit += 32;
}
if (!(word & 0xffff000000000000UL)) {
word <<= 16;
bit += 16;
}
if (!(word & 0xff00000000000000UL)) {
word <<= 8;
bit += 8;
}
if (!(word & 0xf000000000000000UL)) {
word <<= 4;
bit += 4;
}
if (!(word & 0xc000000000000000UL)) {
word <<= 2;
bit += 2;
}
if (!(word & 0x8000000000000000UL)) {
word <<= 1;
bit += 1;
}
return bit;
} else {
union register_pair rp __uninitialized;
rp.even = word;
asm("flogr %[rp],%[rp]"
: [rp] "+d" (rp.pair) : : "cc");
bit = rp.even;
/*
* The result of the flogr instruction is a value in the range
* of 0..64. Let the compiler know that the AND operation can
* be optimized away.
*/
__assume(bit <= 64);
return bit & 127;
}
}
/**
* ffs - find first bit set
* @word: the word to search
*
* This is defined the same way as the libc and
* compiler builtin ffs routines (man ffs).
*/
static __always_inline __flatten __attribute_const__ int ffs(int word)
{
unsigned int val = (unsigned int)word;
return BITS_PER_LONG - __flogr(-val & val);
}
#else /* CONFIG_CC_HAS_BUILTIN_FFS */
#include <asm-generic/bitops/builtin-ffs.h>
#endif /* CONFIG_CC_HAS_BUILTIN_FFS */
#include <asm-generic/bitops/builtin-__ffs.h>
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/builtin-__fls.h>
#include <asm-generic/bitops/builtin-fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm/arch_hweight.h>
#include <asm-generic/bitops/const_hweight.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic-setbit.h>
#endif /* _S390_BITOPS_H */