acrn-hypervisor/hypervisor/include/lib/bits.h

223 lines
5.7 KiB
C

/*-
* Copyright (c) 1998 Doug Rabson
* Copyright (c) 2017 Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef BITS_H
#define BITS_H
#define BUS_LOCK "lock ; "
/**
*
* fls - Find the Last (most significant) bit Set in value and
* return the bit index of that bit.
*
* Bits are numbered starting at 0,the least significant bit.
* A return value of -1 means that the argument was zero.
*
* Examples:
* fls (0x0) = -1
* fls (0x01) = 0
* fls (0xf0) = 7
* ...
* fls (0x80000001) = 31
*
* @param value: 'unsigned int' type value
*
* @return value: zero-based bit index, -1 means 'value' was zero.
*
* **/
static inline int fls(unsigned int value)
{
int ret;
asm volatile("bsrl %1,%0"
: "=r" (ret)
: "rm" (value), "0" (-1));
return ret;
}
static inline int fls64(unsigned long value)
{
int ret;
asm volatile("bsrq %1,%q0"
: "=r" (ret)
: "rm" (value), "0" (-1));
return ret;
}
/**
*
* ffs64 - Find the First (least significant) bit Set in value(Long type)
* and return the index of that bit.
*
* Bits are numbered starting at 0,the least significant bit.
* A return value of -1 means that the argument was zero.
*
* Examples:
* ffs64 (0x0) = -1
* ffs64 (0x01) = 0
* ffs64 (0xf0) = 4
* ffs64 (0xf00) = 8
* ...
* ffs64 (0x8000000000000001) = 0
* ffs64 (0xf000000000000000) = 60
*
* @param value: 'unsigned long' type value
*
* @return value: zero-based bit index, -1 means 'value' was zero.
*
* **/
static inline int ffs64(unsigned long value)
{
int ret;
asm volatile("bsfq %1,%q0"
: "=r" (ret)
: "rm" (value), "0" (-1));
return ret;
}
/*bit scan forward for the least significant bit '0'*/
static inline int ffz64(unsigned long value)
{
return ffs64(~value);
}
/**
* Counts leading zeros.
*
* The number of leading zeros is defined as the number of
* most significant bits which are not '1'. E.g.:
* clz(0x80000000)==0
* clz(0x40000000)==1
* ...
* clz(0x00000001)==31
* clz(0x00000000)==32
*
* @param value:The 32 bit value to count the number of leading zeros.
*
* @return The number of leading zeros in 'value'.
*/
static inline int clz(unsigned int value)
{
return (31 - fls(value));
}
/**
* Counts leading zeros (64 bit version).
*
* @param value:The 64 bit value to count the number of leading zeros.
*
* @return The number of leading zeros in 'value'.
*/
static inline int clz64(unsigned long value)
{
return (63 - fls64(value));
}
/*
* (*addr) |= (1UL<<nr);
*/
#define build_bitmap_set(name, lock, nr, addr) \
static inline void name(int nr, volatile unsigned long *addr) \
{ \
asm volatile(lock "orq %1,%0" \
: "+m" (*addr) \
: "r" (1UL<<nr) \
: "cc", "memory"); \
}
build_bitmap_set(__bitmap_set, "", nr, addr)
build_bitmap_set(bitmap_set, BUS_LOCK, nr, addr)
/*
* (*addr) &= ~(1UL<<nr);
*/
#define build_bitmap_clear(name, lock, nr, addr) \
static inline void name(int nr, volatile unsigned long *addr) \
{ \
asm volatile(lock "andq %1,%0" \
: "+m" (*addr) \
: "r" (~(1UL<<nr)) \
: "cc", "memory"); \
}
build_bitmap_clear(__bitmap_clear, "", nr, addr)
build_bitmap_clear(bitmap_clear, BUS_LOCK, nr, addr)
/*
* return !!((*addr) & (1UL<<nr));
*/
static inline bool bitmap_test(int nr, volatile unsigned long *addr)
{
int32_t ret;
asm volatile("btq %2,%1\n\tsbbl %0, %0"
: "=r" (ret), "=m" (*addr)
: "r" ((long)(nr & 0x3f))
: "cc", "memory");
return (ret != 0);
}
/*
* bool ret = (*addr) & (1UL<<nr);
* (*addr) |= (1UL<<nr);
* return ret;
*/
#define build_bitmap_testandset(name, lock, nr, addr) \
static inline bool name(int nr, volatile unsigned long *addr) \
{ \
int32_t ret; \
asm volatile(lock "btsq %2,%1\n\tsbbl %0,%0" \
: "=r" (ret), "=m" (*addr) \
: "r" ((long)(nr & 0x3f)) \
: "cc", "memory"); \
return (ret != 0); \
}
build_bitmap_testandset(__bitmap_test_and_set, "", nr, addr)
build_bitmap_testandset(bitmap_test_and_set, BUS_LOCK, nr, addr)
/*
* bool ret = (*addr) & (1UL<<nr);
* (*addr) &= ~(1UL<<nr);
* return ret;
*/
#define build_bitmap_testandclear(name, lock, nr, addr) \
static inline bool name(int nr, volatile unsigned long *addr) \
{ \
int32_t ret; \
asm volatile(lock "btrq %2,%1\n\tsbbl %0,%0" \
: "=r" (ret), "=m" (*addr) \
: "r" ((long)(nr & 0x3f)) \
: "cc", "memory"); \
return (ret != 0); \
}
build_bitmap_testandclear(__bitmap_test_and_clear, "", nr, addr)
build_bitmap_testandclear(bitmap_test_and_clear, BUS_LOCK, nr, addr)
#endif /* BITS_H*/