src/helper/bits.h

   1 /*
   2  * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
   3  * Author(s): Antonio Borneo <borneo.antonio@gmail.com> for STMicroelectronics
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /*
  20  * The content of this file is mainly copied/inspired from Linux kernel
  21  * code in include/linux/types.h include/linux/bitmap.h include/linux/bitops.h
  22  */
  23
  24 #ifndef OPENOCD_HELPER_BITS_H
  25 #define OPENOCD_HELPER_BITS_H
  26
  27 #include <helper/replacements.h>
  28 #include <helper/types.h>
  29
  30 #define BIT(nr)                     (1UL << (nr))
  31 #define BIT_ULL(nr)                 (1ULL << (nr))
  32 #define BITS_PER_BYTE               8
  33 #define BITS_PER_LONG               (BITS_PER_BYTE * sizeof(long))
  34 #define BITS_PER_LONG_LONG          (BITS_PER_BYTE * sizeof(long long))
  35 #define GENMASK(h, l)               (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
  36 #define GENMASK_ULL(h, l)           (((~0ULL) - (1ULL << (l)) + 1) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
  37 #define BITS_TO_LONGS(nr)           DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
  38 #define BIT_MASK(nr)                (1UL << ((nr) % BITS_PER_LONG))
  39 #define BIT_WORD(nr)                ((nr) / BITS_PER_LONG)
  40 #define DECLARE_BITMAP(name, bits)  unsigned long name[BITS_TO_LONGS(bits)]
  41
  42 /**
  43  * bitmap_zero - Clears all the bits in memory
  44  * @param dst the address of the bitmap
  45  * @param nbits the number of bits to clear
  46  */
  47 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
  48 {
  49         unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
  50         memset(dst, 0, len);
  51 }
  52
  53 /**
  54  * clear_bit - Clear a bit in memory
  55  * @param nr the bit to set
  56  * @param addr the address to start counting from
  57  */
  58 static inline void clear_bit(unsigned int nr, volatile unsigned long *addr)
  59 {
  60         unsigned long mask = BIT_MASK(nr);
  61         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  62
  63         *p &= ~mask;
  64 }
  65
  66 /**
  67  * set_bit - Set a bit in memory
  68  * @param nr the bit to set
  69  * @param addr the address to start counting from
  70  */
  71 static inline void set_bit(unsigned int nr, volatile unsigned long *addr)
  72 {
  73         unsigned long mask = BIT_MASK(nr);
  74         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  75
  76         *p |= mask;
  77 }
  78
  79 /**
  80  * test_bit - Determine whether a bit is set
  81  * @param nr bit number to test
  82  * @param addr Address to start counting from
  83  */
  84 static inline int test_bit(unsigned int nr, const volatile unsigned long *addr)
  85 {
  86         return 1UL & (addr[BIT_WORD(nr)] >> (nr % BITS_PER_LONG));
  87 }
  88
  89 #endif /* OPENOCD_HELPER_BITS_H */