u-boot/arch/riscv/include/asm/bitops.h
Bryan O'Donoghue accdce5f86 riscv: Define PLATFORM__CLEAR_BIT for generic_clear_bit()
riscv bitops.h provides a __clear_bit() but does not define
PLATFORM__CLEAR_BIT as a result generic_clear_bit() is used instead of the
architecturally provided __clear_bit().

This patch defines PLATFORM__CLEAR_BIT which means that __clear_bit() in
riscv bitops.h will be called whenever generic_clear_bit() is called - as
opposed to the default cross-platform generic_clear_bit().

Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Rick Chen <rick@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
2018-05-15 21:44:05 -04:00

177 lines
3.9 KiB
C

/*
* Copyright 1995, Russell King.
* Various bits and pieces copyrights include:
* Linus Torvalds (test_bit).
*
* Copyright (C) 2017 Andes Technology Corporation
* Rick Chen, Andes Technology Corporation <rick@andestech.com>
*
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*
* Please note that the code in this file should never be included
* from user space. Many of these are not implemented in assembler
* since they would be too costly. Also, they require priviledged
* instructions (which are not available from user mode) to ensure
* that they are atomic.
*/
#ifndef __ASM_RISCV_BITOPS_H
#define __ASM_RISCV_BITOPS_H
#ifdef __KERNEL__
#include <asm/system.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/__ffs.h>
#define smp_mb__before_clear_bit() do { } while (0)
#define smp_mb__after_clear_bit() do { } while (0)
/*
* Function prototypes to keep gcc -Wall happy.
*/
static inline void __set_bit(int nr, void *addr)
{
int *a = (int *)addr;
int mask;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
*a |= mask;
}
#define PLATFORM__SET_BIT
static inline void __clear_bit(int nr, void *addr)
{
int *a = (int *)addr;
int mask;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
*a &= ~mask;
}
#define PLATFORM__CLEAR_BIT
static inline void __change_bit(int nr, void *addr)
{
int mask;
unsigned long *ADDR = (unsigned long *)addr;
ADDR += nr >> 5;
mask = 1 << (nr & 31);
*ADDR ^= mask;
}
static inline int __test_and_set_bit(int nr, void *addr)
{
int mask, retval;
unsigned int *a = (unsigned int *)addr;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
retval = (mask & *a) != 0;
*a |= mask;
return retval;
}
static inline int __test_and_clear_bit(int nr, void *addr)
{
int mask, retval;
unsigned int *a = (unsigned int *)addr;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
retval = (mask & *a) != 0;
*a &= ~mask;
return retval;
}
static inline int __test_and_change_bit(int nr, void *addr)
{
int mask, retval;
unsigned int *a = (unsigned int *)addr;
a += nr >> 5;
mask = 1 << (nr & 0x1f);
retval = (mask & *a) != 0;
*a ^= mask;
return retval;
}
/*
* This routine doesn't need to be atomic.
*/
static inline int test_bit(int nr, const void *addr)
{
return ((unsigned char *)addr)[nr >> 3] & (1U << (nr & 7));
}
/*
* ffz = Find First Zero in word. Undefined if no zero exists,
* so code should check against ~0UL first..
*/
static inline unsigned long ffz(unsigned long word)
{
int k;
word = ~word;
k = 31;
if (word & 0x0000ffff) {
k -= 16; word <<= 16;
}
if (word & 0x00ff0000) {
k -= 8; word <<= 8;
}
if (word & 0x0f000000) {
k -= 4; word <<= 4;
}
if (word & 0x30000000) {
k -= 2; word <<= 2;
}
if (word & 0x40000000)
k -= 1;
return k;
}
/*
* ffs: find first bit set. This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
/*
* redefined in include/linux/bitops.h
* #define ffs(x) generic_ffs(x)
*/
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
*/
#define hweight32(x) generic_hweight32(x)
#define hweight16(x) generic_hweight16(x)
#define hweight8(x) generic_hweight8(x)
#define ext2_set_bit test_and_set_bit
#define ext2_clear_bit test_and_clear_bit
#define ext2_test_bit test_bit
#define ext2_find_first_zero_bit find_first_zero_bit
#define ext2_find_next_zero_bit find_next_zero_bit
/* Bitmap functions for the minix filesystem. */
#define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr)
#define minix_set_bit(nr, addr) set_bit(nr, addr)
#define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr)
#define minix_test_bit(nr, addr) test_bit(nr, addr)
#define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size)
#endif /* __KERNEL__ */
#endif /* __ASM_RISCV_BITOPS_H */