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+/*
+ * PowerPC64 atomic bit operations.
+ * Dave Engebretsen, Todd Inglett, Don Reed, Pat McCarthy, Peter Bergner,
+ * Anton Blanchard
+ *
+ * Originally taken from the 32b PPC code. Modified to use 64b values for
+ * the various counters & memory references.
+ *
+ * Bitops are odd when viewed on big-endian systems. They were designed
+ * on little endian so the size of the bitset doesn't matter (low order bytes
+ * come first) as long as the bit in question is valid.
+ *
+ * Bits are "tested" often using the C expression (val & (1<<nr)) so we do
+ * our best to stay compatible with that. The assumption is that val will
+ * be unsigned long for such tests. As such, we assume the bits are stored
+ * as an array of unsigned long (the usual case is a single unsigned long,
+ * of course). Here's an example bitset with bit numbering:
+ *
+ * |63..........0|127........64|195.......128|255.......196|
+ *
+ * This leads to a problem. If an int, short or char is passed as a bitset
+ * it will be a bad memory reference since we want to store in chunks
+ * of unsigned long (64 bits here) size.
+ *
+ * There are a few little-endian macros used mostly for filesystem bitmaps,
+ * these work on similar bit arrays layouts, but byte-oriented:
+ *
+ * |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
+ *
+ * The main difference is that bit 3-5 in the bit number field needs to be
+ * reversed compared to the big-endian bit fields. This can be achieved
+ * by XOR with 0b111000 (0x38).
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _PPC64_BITOPS_H
+#define _PPC64_BITOPS_H
+
+#ifdef __KERNEL__
+
+#include <asm/memory.h>
+
+/*
+ * clear_bit doesn't imply a memory barrier
+ */
+#define smp_mb__before_clear_bit() smp_mb()
+#define smp_mb__after_clear_bit() smp_mb()
+
+static __inline__ int test_bit(unsigned long nr, __const__ volatile unsigned long *addr)
+{
+ return (1UL & (addr[nr >> 6] >> (nr & 63)));
+}
+
+static __inline__ void set_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long old;
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ __asm__ __volatile__(
+"1: ldarx %0,0,%3 # set_bit\n\
+ or %0,%0,%2\n\
+ stdcx. %0,0,%3\n\
+ bne- 1b"
+ : "=&r" (old), "=m" (*p)
+ : "r" (mask), "r" (p), "m" (*p)
+ : "cc");
+}
+
+static __inline__ void clear_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long old;
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ __asm__ __volatile__(
+"1: ldarx %0,0,%3 # clear_bit\n\
+ andc %0,%0,%2\n\
+ stdcx. %0,0,%3\n\
+ bne- 1b"
+ : "=&r" (old), "=m" (*p)
+ : "r" (mask), "r" (p), "m" (*p)
+ : "cc");
+}
+
+static __inline__ void change_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long old;
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ __asm__ __volatile__(
+"1: ldarx %0,0,%3 # change_bit\n\
+ xor %0,%0,%2\n\
+ stdcx. %0,0,%3\n\
+ bne- 1b"
+ : "=&r" (old), "=m" (*p)
+ : "r" (mask), "r" (p), "m" (*p)
+ : "cc");
+}
+
+static __inline__ int test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long old, t;
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ __asm__ __volatile__(
+ EIEIO_ON_SMP
+"1: ldarx %0,0,%3 # test_and_set_bit\n\
+ or %1,%0,%2 \n\
+ stdcx. %1,0,%3 \n\
+ bne- 1b"
+ ISYNC_ON_SMP
+ : "=&r" (old), "=&r" (t)
+ : "r" (mask), "r" (p)
+ : "cc", "memory");
+
+ return (old & mask) != 0;
+}
+
+static __inline__ int test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long old, t;
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ __asm__ __volatile__(
+ EIEIO_ON_SMP
+"1: ldarx %0,0,%3 # test_and_clear_bit\n\
+ andc %1,%0,%2\n\
+ stdcx. %1,0,%3\n\
+ bne- 1b"
+ ISYNC_ON_SMP
+ : "=&r" (old), "=&r" (t)
+ : "r" (mask), "r" (p)
+ : "cc", "memory");
+
+ return (old & mask) != 0;
+}
+
+static __inline__ int test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long old, t;
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ __asm__ __volatile__(
+ EIEIO_ON_SMP
+"1: ldarx %0,0,%3 # test_and_change_bit\n\
+ xor %1,%0,%2\n\
+ stdcx. %1,0,%3\n\
+ bne- 1b"
+ ISYNC_ON_SMP
+ : "=&r" (old), "=&r" (t)
+ : "r" (mask), "r" (p)
+ : "cc", "memory");
+
+ return (old & mask) != 0;
+}
+
+static __inline__ void set_bits(unsigned long mask, unsigned long *addr)
+{
+ unsigned long old;
+
+ __asm__ __volatile__(
+"1: ldarx %0,0,%3 # set_bit\n\
+ or %0,%0,%2\n\
+ stdcx. %0,0,%3\n\
+ bne- 1b"
+ : "=&r" (old), "=m" (*addr)
+ : "r" (mask), "r" (addr), "m" (*addr)
+ : "cc");
+}
+
+/*
+ * non-atomic versions
+ */
+static __inline__ void __set_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ *p |= mask;
+}
+
+static __inline__ void __clear_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ *p &= ~mask;
+}
+
+static __inline__ void __change_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+
+ *p ^= mask;
+}
+
+static __inline__ int __test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+ unsigned long old = *p;
+
+ *p = old | mask;
+ return (old & mask) != 0;
+}
+
+static __inline__ int __test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+ unsigned long old = *p;
+
+ *p = old & ~mask;
+ return (old & mask) != 0;
+}
+
+static __inline__ int __test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
+{
+ unsigned long mask = 1UL << (nr & 0x3f);
+ unsigned long *p = ((unsigned long *)addr) + (nr >> 6);
+ unsigned long old = *p;
+
+ *p = old ^ mask;
+ return (old & mask) != 0;
+}
+
+/*
+ * Return the zero-based bit position (from RIGHT TO LEFT, 63 -> 0) of the
+ * most significant (left-most) 1-bit in a double word.
+ */
+static __inline__ int __ilog2(unsigned long x)
+{
+ int lz;
+
+ asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x));
+ return 63 - lz;
+}
+
+/*
+ * Determines the bit position of the least significant (rightmost) 0 bit
+ * in the specified double word. The returned bit position will be zero-based,
+ * starting from the right side (63 - 0).
+ */
+static __inline__ unsigned long ffz(unsigned long x)
+{
+ /* no zero exists anywhere in the 8 byte area. */
+ if ((x = ~x) == 0)
+ return 64;
+
+ /*
+ * Calculate the bit position of the least signficant '1' bit in x
+ * (since x has been changed this will actually be the least signficant
+ * '0' bit in * the original x). Note: (x & -x) gives us a mask that
+ * is the least significant * (RIGHT-most) 1-bit of the value in x.
+ */
+ return __ilog2(x & -x);
+}
+
+static __inline__ int __ffs(unsigned long x)
+{
+ return __ilog2(x & -x);
+}
+
+/*
+ * 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).
+ */
+static __inline__ int ffs(int x)
+{
+ unsigned long i = (unsigned long)x;
+ return __ilog2(i & -i) + 1;
+}
+
+/*
+ * fls: find last (most-significant) bit set.
+ * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
+ */
+#define fls(x) generic_fls(x)
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+#define hweight64(x) generic_hweight64(x)
+#define hweight32(x) generic_hweight32(x)
+#define hweight16(x) generic_hweight16(x)
+#define hweight8(x) generic_hweight8(x)
+
+extern unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, unsigned long offset);
+#define find_first_zero_bit(addr, size) \
+ find_next_zero_bit((addr), (size), 0)
+
+extern unsigned long find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset);
+#define find_first_bit(addr, size) \
+ find_next_bit((addr), (size), 0)
+
+extern unsigned long find_next_zero_le_bit(const unsigned long *addr, unsigned long size, unsigned long offset);
+#define find_first_zero_le_bit(addr, size) \
+ find_next_zero_le_bit((addr), (size), 0)
+
+static __inline__ int test_le_bit(unsigned long nr, __const__ unsigned long * addr)
+{
+ __const__ unsigned char *ADDR = (__const__ unsigned char *) addr;
+ return (ADDR[nr >> 3] >> (nr & 7)) & 1;
+}
+
+#define test_and_clear_le_bit(nr, addr) \
+ test_and_clear_bit((nr) ^ 0x38, (addr))
+#define test_and_set_le_bit(nr, addr) \
+ test_and_set_bit((nr) ^ 0x38, (addr))
+
+/*
+ * non-atomic versions
+ */
+
+#define __set_le_bit(nr, addr) \
+ __set_bit((nr) ^ 0x38, (addr))
+#define __clear_le_bit(nr, addr) \
+ __clear_bit((nr) ^ 0x38, (addr))
+#define __test_and_clear_le_bit(nr, addr) \
+ __test_and_clear_bit((nr) ^ 0x38, (addr))
+#define __test_and_set_le_bit(nr, addr) \
+ __test_and_set_bit((nr) ^ 0x38, (addr))
+
+#define ext2_set_bit(nr,addr) \
+ __test_and_set_le_bit((nr), (unsigned long*)addr)
+#define ext2_clear_bit(nr, addr) \
+ __test_and_clear_le_bit((nr), (unsigned long*)addr)
+
+#define ext2_set_bit_atomic(lock, nr, addr) \
+ test_and_set_le_bit((nr), (unsigned long*)addr)
+#define ext2_clear_bit_atomic(lock, nr, addr) \
+ test_and_clear_le_bit((nr), (unsigned long*)addr)
+
+
+#define ext2_test_bit(nr, addr) test_le_bit((nr),(unsigned long*)addr)
+#define ext2_find_first_zero_bit(addr, size) \
+ find_first_zero_le_bit((unsigned long*)addr, size)
+#define ext2_find_next_zero_bit(addr, size, off) \
+ find_next_zero_le_bit((unsigned long*)addr, size, off)
+
+#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 /* _PPC64_BITOPS_H */