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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-ia64/bitops.h
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Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-ia64/bitops.h')
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diff --git a/include/asm-ia64/bitops.h b/include/asm-ia64/bitops.h
new file mode 100644
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+++ b/include/asm-ia64/bitops.h
@@ -0,0 +1,410 @@
+#ifndef _ASM_IA64_BITOPS_H
+#define _ASM_IA64_BITOPS_H
+
+/*
+ * Copyright (C) 1998-2003 Hewlett-Packard Co
+ * David Mosberger-Tang <davidm@hpl.hp.com>
+ *
+ * 02/06/02 find_next_bit() and find_first_bit() added from Erich Focht's ia64 O(1)
+ * scheduler patch
+ */
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/bitops.h>
+#include <asm/intrinsics.h>
+
+/**
+ * set_bit - Atomically set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * This function is atomic and may not be reordered. See __set_bit()
+ * if you do not require the atomic guarantees.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ *
+ * The address must be (at least) "long" aligned.
+ * Note that there are driver (e.g., eepro100) which use these operations to operate on
+ * hw-defined data-structures, so we can't easily change these operations to force a
+ * bigger alignment.
+ *
+ * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
+ */
+static __inline__ void
+set_bit (int nr, volatile void *addr)
+{
+ __u32 bit, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ bit = 1 << (nr & 31);
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old | bit;
+ } while (cmpxchg_acq(m, old, new) != old);
+}
+
+/**
+ * __set_bit - Set a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Unlike set_bit(), this function is non-atomic and may be reordered.
+ * If it's called on the same region of memory simultaneously, the effect
+ * may be that only one operation succeeds.
+ */
+static __inline__ void
+__set_bit (int nr, volatile void *addr)
+{
+ *((__u32 *) addr + (nr >> 5)) |= (1 << (nr & 31));
+}
+
+/*
+ * clear_bit() has "acquire" semantics.
+ */
+#define smp_mb__before_clear_bit() smp_mb()
+#define smp_mb__after_clear_bit() do { /* skip */; } while (0)
+
+/**
+ * clear_bit - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * clear_bit() is atomic and may not be reordered. However, it does
+ * not contain a memory barrier, so if it is used for locking purposes,
+ * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
+ * in order to ensure changes are visible on other processors.
+ */
+static __inline__ void
+clear_bit (int nr, volatile void *addr)
+{
+ __u32 mask, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ mask = ~(1 << (nr & 31));
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old & mask;
+ } while (cmpxchg_acq(m, old, new) != old);
+}
+
+/**
+ * __clear_bit - Clears a bit in memory (non-atomic version)
+ */
+static __inline__ void
+__clear_bit (int nr, volatile void *addr)
+{
+ volatile __u32 *p = (__u32 *) addr + (nr >> 5);
+ __u32 m = 1 << (nr & 31);
+ *p &= ~m;
+}
+
+/**
+ * change_bit - Toggle a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * change_bit() is atomic and may not be reordered.
+ * Note that @nr may be almost arbitrarily large; this function is not
+ * restricted to acting on a single-word quantity.
+ */
+static __inline__ void
+change_bit (int nr, volatile void *addr)
+{
+ __u32 bit, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ bit = (1 << (nr & 31));
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old ^ bit;
+ } while (cmpxchg_acq(m, old, new) != old);
+}
+
+/**
+ * __change_bit - Toggle a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ *
+ * Unlike change_bit(), this function is non-atomic and may be reordered.
+ * If it's called on the same region of memory simultaneously, the effect
+ * may be that only one operation succeeds.
+ */
+static __inline__ void
+__change_bit (int nr, volatile void *addr)
+{
+ *((__u32 *) addr + (nr >> 5)) ^= (1 << (nr & 31));
+}
+
+/**
+ * test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static __inline__ int
+test_and_set_bit (int nr, volatile void *addr)
+{
+ __u32 bit, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ bit = 1 << (nr & 31);
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old | bit;
+ } while (cmpxchg_acq(m, old, new) != old);
+ return (old & bit) != 0;
+}
+
+/**
+ * __test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.
+ * If two examples of this operation race, one can appear to succeed
+ * but actually fail. You must protect multiple accesses with a lock.
+ */
+static __inline__ int
+__test_and_set_bit (int nr, volatile void *addr)
+{
+ __u32 *p = (__u32 *) addr + (nr >> 5);
+ __u32 m = 1 << (nr & 31);
+ int oldbitset = (*p & m) != 0;
+
+ *p |= m;
+ return oldbitset;
+}
+
+/**
+ * test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static __inline__ int
+test_and_clear_bit (int nr, volatile void *addr)
+{
+ __u32 mask, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ mask = ~(1 << (nr & 31));
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old & mask;
+ } while (cmpxchg_acq(m, old, new) != old);
+ return (old & ~mask) != 0;
+}
+
+/**
+ * __test_and_clear_bit - Clear a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is non-atomic and can be reordered.
+ * If two examples of this operation race, one can appear to succeed
+ * but actually fail. You must protect multiple accesses with a lock.
+ */
+static __inline__ int
+__test_and_clear_bit(int nr, volatile void * addr)
+{
+ __u32 *p = (__u32 *) addr + (nr >> 5);
+ __u32 m = 1 << (nr & 31);
+ int oldbitset = *p & m;
+
+ *p &= ~m;
+ return oldbitset;
+}
+
+/**
+ * test_and_change_bit - Change a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This operation is atomic and cannot be reordered.
+ * It also implies a memory barrier.
+ */
+static __inline__ int
+test_and_change_bit (int nr, volatile void *addr)
+{
+ __u32 bit, old, new;
+ volatile __u32 *m;
+ CMPXCHG_BUGCHECK_DECL
+
+ m = (volatile __u32 *) addr + (nr >> 5);
+ bit = (1 << (nr & 31));
+ do {
+ CMPXCHG_BUGCHECK(m);
+ old = *m;
+ new = old ^ bit;
+ } while (cmpxchg_acq(m, old, new) != old);
+ return (old & bit) != 0;
+}
+
+/*
+ * WARNING: non atomic version.
+ */
+static __inline__ int
+__test_and_change_bit (int nr, void *addr)
+{
+ __u32 old, bit = (1 << (nr & 31));
+ __u32 *m = (__u32 *) addr + (nr >> 5);
+
+ old = *m;
+ *m = old ^ bit;
+ return (old & bit) != 0;
+}
+
+static __inline__ int
+test_bit (int nr, const volatile void *addr)
+{
+ return 1 & (((const volatile __u32 *) addr)[nr >> 5] >> (nr & 31));
+}
+
+/**
+ * ffz - find the first zero bit in a long word
+ * @x: The long word to find the bit in
+ *
+ * Returns the bit-number (0..63) of the first (least significant) zero bit. Undefined if
+ * no zero exists, so code should check against ~0UL first...
+ */
+static inline unsigned long
+ffz (unsigned long x)
+{
+ unsigned long result;
+
+ result = ia64_popcnt(x & (~x - 1));
+ return result;
+}
+
+/**
+ * __ffs - find first bit in word.
+ * @x: The word to search
+ *
+ * Undefined if no bit exists, so code should check against 0 first.
+ */
+static __inline__ unsigned long
+__ffs (unsigned long x)
+{
+ unsigned long result;
+
+ result = ia64_popcnt((x-1) & ~x);
+ return result;
+}
+
+#ifdef __KERNEL__
+
+/*
+ * find_last_zero_bit - find the last zero bit in a 64 bit quantity
+ * @x: The value to search
+ */
+static inline unsigned long
+ia64_fls (unsigned long x)
+{
+ long double d = x;
+ long exp;
+
+ exp = ia64_getf_exp(d);
+ return exp - 0xffff;
+}
+
+static inline int
+fls (int x)
+{
+ return ia64_fls((unsigned int) 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): it operates on
+ * "int" values only and the result value is the bit number + 1. ffs(0) is defined to
+ * return zero.
+ */
+#define ffs(x) __builtin_ffs(x)
+
+/*
+ * hweightN: returns the hamming weight (i.e. the number
+ * of bits set) of a N-bit word
+ */
+static __inline__ unsigned long
+hweight64 (unsigned long x)
+{
+ unsigned long result;
+ result = ia64_popcnt(x);
+ return result;
+}
+
+#define hweight32(x) (unsigned int) hweight64((x) & 0xfffffffful)
+#define hweight16(x) (unsigned int) hweight64((x) & 0xfffful)
+#define hweight8(x) (unsigned int) hweight64((x) & 0xfful)
+
+#endif /* __KERNEL__ */
+
+extern int __find_next_zero_bit (const void *addr, unsigned long size,
+ unsigned long offset);
+extern int __find_next_bit(const void *addr, unsigned long size,
+ unsigned long offset);
+
+#define find_next_zero_bit(addr, size, offset) \
+ __find_next_zero_bit((addr), (size), (offset))
+#define find_next_bit(addr, size, offset) \
+ __find_next_bit((addr), (size), (offset))
+
+/*
+ * The optimizer actually does good code for this case..
+ */
+#define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0)
+
+#define find_first_bit(addr, size) find_next_bit((addr), (size), 0)
+
+#ifdef __KERNEL__
+
+#define __clear_bit(nr, addr) clear_bit(nr, addr)
+
+#define ext2_set_bit test_and_set_bit
+#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
+#define ext2_clear_bit test_and_clear_bit
+#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
+#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)
+
+static inline int
+sched_find_first_bit (unsigned long *b)
+{
+ if (unlikely(b[0]))
+ return __ffs(b[0]);
+ if (unlikely(b[1]))
+ return 64 + __ffs(b[1]);
+ return __ffs(b[2]) + 128;
+}
+
+#endif /* __KERNEL__ */
+
+#endif /* _ASM_IA64_BITOPS_H */