text: /* 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 <asm/atomic_ops.h>
  #include <asm/barrier.h>
  
  #define __BITOPS_WORDS(bits) (((bits) + BITS_PER_LONG - 1) / BITS_PER_LONG)
  
  static inline unsigned long *
  __bitops_word(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long addr;
  
  	addr = (unsigned long)ptr + ((nr ^ (nr & (BITS_PER_LONG - 1))) >> 3);
  	return (unsigned long *)addr;
  }
  
  static inline unsigned char *
  __bitops_byte(unsigned long nr, volatile unsigned long *ptr)
  {
  	return ((unsigned char *)ptr) + ((nr ^ (BITS_PER_LONG - 8)) >> 3);
  }
  
  static inline void set_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long *addr = __bitops_word(nr, ptr);
  	unsigned long mask;
  
  #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  	if (__builtin_constant_p(nr)) {
  		unsigned char *caddr = __bitops_byte(nr, ptr);
  
  		asm volatile(
  			"oi	%0,%b1\n"
  			: "+Q" (*caddr)
  			: "i" (1 << (nr & 7))
  			: "cc", "memory");
  		return;
  	}
  #endif
  	mask = 1UL << (nr & (BITS_PER_LONG - 1));
  	__atomic64_or(mask, addr);
  }
  
  static inline void clear_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long *addr = __bitops_word(nr, ptr);
  	unsigned long mask;
  
  #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  	if (__builtin_constant_p(nr)) {
  		unsigned char *caddr = __bitops_byte(nr, ptr);
  
  		asm volatile(
  			"ni	%0,%b1\n"
  			: "+Q" (*caddr)
  			: "i" (~(1 << (nr & 7)))
  			: "cc", "memory");
  		return;
  	}
  #endif
  	mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
  	__atomic64_and(mask, addr);
  }
  
  static inline void change_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long *addr = __bitops_word(nr, ptr);
  	unsigned long mask;
  
  #ifdef CONFIG_HAVE_MARCH_ZEC12_FEATURES
  	if (__builtin_constant_p(nr)) {
  		unsigned char *caddr = __bitops_byte(nr, ptr);
  
  		asm volatile(
  			"xi	%0,%b1\n"
  			: "+Q" (*caddr)
  			: "i" (1 << (nr & 7))
  			: "cc", "memory");
  		return;
  	}
  #endif
  	mask = 1UL << (nr & (BITS_PER_LONG - 1));
  	__atomic64_xor(mask, addr);
  }
  
  static inline int
  test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long *addr = __bitops_word(nr, ptr);
  	unsigned long old, mask;
  
  	mask = 1UL << (nr & (BITS_PER_LONG - 1));
  	old = __atomic64_or_barrier(mask, addr);
  	return (old & mask) != 0;
  }
  
  static inline int
  test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long *addr = __bitops_word(nr, ptr);
  	unsigned long old, mask;
  
  	mask = ~(1UL << (nr & (BITS_PER_LONG - 1)));
  	old = __atomic64_and_barrier(mask, addr);
  	return (old & ~mask) != 0;
  }
  
  static inline int
  test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned long *addr = __bitops_word(nr, ptr);
  	unsigned long old, mask;
  
  	mask = 1UL << (nr & (BITS_PER_LONG - 1));
  	old = __atomic64_xor_barrier(mask, addr);
  	return (old & mask) != 0;
  }
  
  static inline void __set_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned char *addr = __bitops_byte(nr, ptr);
  
  	*addr |= 1 << (nr & 7);
  }
  
  static inline void 
  __clear_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned char *addr = __bitops_byte(nr, ptr);
  
  	*addr &= ~(1 << (nr & 7));
  }
  
  static inline void __change_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned char *addr = __bitops_byte(nr, ptr);
  
  	*addr ^= 1 << (nr & 7);
  }
  
  static inline int
  __test_and_set_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned char *addr = __bitops_byte(nr, ptr);
  	unsigned char ch;
  
  	ch = *addr;
  	*addr |= 1 << (nr & 7);
  	return (ch >> (nr & 7)) & 1;
  }
  
  static inline int
  __test_and_clear_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned char *addr = __bitops_byte(nr, ptr);
  	unsigned char ch;
  
  	ch = *addr;
  	*addr &= ~(1 << (nr & 7));
  	return (ch >> (nr & 7)) & 1;
  }
  
  static inline int
  __test_and_change_bit(unsigned long nr, volatile unsigned long *ptr)
  {
  	unsigned char *addr = __bitops_byte(nr, ptr);
  	unsigned char ch;
  
  	ch = *addr;
  	*addr ^= 1 << (nr & 7);
  	return (ch >> (nr & 7)) & 1;
  }
  
  static inline int test_bit(unsigned long nr, const volatile unsigned long *ptr)
  {
  	const volatile unsigned char *addr;
  
  	addr = ((const volatile unsigned char *)ptr);
  	addr += (nr ^ (BITS_PER_LONG - 8)) >> 3;
  	return (*addr >> (nr & 7)) & 1;
  }
  
  static inline int test_and_set_bit_lock(unsigned long nr,
  					volatile unsigned long *ptr)
  {
  	if (test_bit(nr, ptr))
  		return 1;
  	return test_and_set_bit(nr, ptr);
  }
  
  static inline void clear_bit_unlock(unsigned long nr,
  				    volatile unsigned long *ptr)
  {
  	smp_mb__before_atomic();
  	clear_bit(nr, ptr);
  }
  
  static inline void __clear_bit_unlock(unsigned long nr,
  				      volatile unsigned long *ptr)
  {
  	smp_mb();
  	__clear_bit(nr, ptr);
  }
  
  /*
   * 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 int 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 int test_bit_inv(unsigned long nr,
  			       const volatile unsigned long *ptr)
  {
  	return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
  }
  
  #ifdef CONFIG_HAVE_MARCH_Z9_109_FEATURES
  
  /**
   * __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 inline unsigned char __flogr(unsigned long word)
  {
  	if (__builtin_constant_p(word)) {
  		unsigned long 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 {
  		register unsigned long bit asm("4") = word;
  		register unsigned long out asm("5");
  
  		asm volatile(
  			"       flogr   %[bit],%[bit]\n"
  			: [bit] "+d" (bit), [out] "=d" (out) : : "cc");
  		return bit;
  	}
  }
  
  /**
   * __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 __flogr(-word & word) ^ (BITS_PER_LONG - 1);
  }
  
  /**
   * 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 inline int ffs(int word)
  {
  	unsigned long mask = 2 * BITS_PER_LONG - 1;
  	unsigned int val = (unsigned int)word;
  
  	return (1 + (__flogr(-val & val) ^ (BITS_PER_LONG - 1))) & mask;
  }
  
  /**
   * __fls - find last (most-significant) set bit in a long word
   * @word: the word to search
   *
   * Undefined if no set bit exists, so code should check against 0 first.
   */
  static inline unsigned long __fls(unsigned long word)
  {
  	return __flogr(word) ^ (BITS_PER_LONG - 1);
  }
  
  /**
   * fls64 - find last set bit in a 64-bit word
   * @word: the word to search
   *
   * This is defined in a similar way as the libc and compiler builtin
   * ffsll, but returns the position of the most significant set bit.
   *
   * fls64(value) returns 0 if value is 0 or the position of the last
   * set bit if value is nonzero. The last (most significant) bit is
   * at position 64.
   */
  static inline int fls64(unsigned long word)
  {
  	unsigned long mask = 2 * BITS_PER_LONG - 1;
  
  	return (1 + (__flogr(word) ^ (BITS_PER_LONG - 1))) & mask;
  }
  
  /**
   * fls - find last (most-significant) bit set
   * @word: the word to search
   *
   * This is defined the same way as ffs.
   * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
   */
  static inline int fls(unsigned int word)
  {
  	return fls64(word);
  }
  
  #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
  
  #include <asm-generic/bitops/__ffs.h>
  #include <asm-generic/bitops/ffs.h>
  #include <asm-generic/bitops/__fls.h>
  #include <asm-generic/bitops/fls.h>
  #include <asm-generic/bitops/fls64.h>
  
  #endif /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */
  
  #include <asm-generic/bitops/ffz.h>
  #include <asm-generic/bitops/find.h>
  #include <asm-generic/bitops/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 */
  