+/*****************************************************************************
+ * kernelutils-x86_64.h
+ *
+ * This file holds the code needed by LTT usertrace that comes from the
+ * kernel headers. Since including kernel headers is not recommended in
+ * userspace programs/libraries, we rewrote implementations HIGHLY INSPIRED
+ * (i.e. copied/pasted) from the original kernel headers (2.6.17).
+ *
+ * Martin Bisson, July 2006
+ */
+
+#ifndef _KERNELUTILS_X86_64_H
+#define _KERNELUTILS_X86_64_H
+
+// We are careful, so we assume a possibly SMP machine
+#define LOCK "lock ; "
+#define LOCK_PREFIX "lock ; "
+
+
+
+
+// From atomic.h
+
+
+/*
+ * Make sure gcc doesn't try to be clever and move things around
+ * on us. We need to use _exactly_ the address the user gave us,
+ * not some alias that contains the same information.
+ */
+typedef struct { volatile int counter; } atomic_t;
+
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+#define atomic_read(v) ((v)->counter)
+
+/**
+ * atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.
+ */
+static __inline__ void atomic_add(int i, atomic_t *v)
+{
+ __asm__ __volatile__(
+ LOCK "addl %1,%0"
+ :"=m" (v->counter)
+ :"ir" (i), "m" (v->counter));
+}
+
+/**
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.
+ */
+static __inline__ void atomic_inc(atomic_t *v)
+{
+ __asm__ __volatile__(
+ LOCK "incl %0"
+ :"=m" (v->counter)
+ :"m" (v->counter));
+}
+
+/**
+ * atomic_add_return - add and return
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __inline__ int atomic_add_return(int i, atomic_t *v)
+{
+ int __i = i;
+ __asm__ __volatile__(
+ LOCK "xaddl %0, %1;"
+ :"=r"(i)
+ :"m"(v->counter), "0"(i));
+ return i + __i;
+}
+
+
+
+
+// From system.h
+
+#define __xg(x) ((volatile long *)(x))
+
+
+/*
+ * Atomic compare and exchange. Compare OLD with MEM, if identical,
+ * store NEW in MEM. Return the initial value in MEM. Success is
+ * indicated by comparing RETURN with OLD.
+ */
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long prev;
+ switch (size) {
+ case 1:
+ __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
+ : "=a"(prev)
+ : "q"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ case 2:
+ __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
+ : "=a"(prev)
+ : "r"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ case 4:
+ __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2"
+ : "=a"(prev)
+ : "r"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ case 8:
+ __asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2"
+ : "=a"(prev)
+ : "r"(new), "m"(*__xg(ptr)), "0"(old)
+ : "memory");
+ return prev;
+ }
+ return old;
+}
+
+#define cmpxchg(ptr,o,n)\
+ ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
+ (unsigned long)(n),sizeof(*(ptr))))
+
+
+
+
+// From msr.h
+
+
+#define rdtscll(val) do { \
+ unsigned int __a,__d; \
+ asm volatile("rdtsc" : "=a" (__a), "=d" (__d)); \
+ (val) = ((unsigned long)__a) | (((unsigned long)__d)<<32); \
+} while(0)
+
+
+
+
+// From timex.h
+
+typedef unsigned long long cycles_t;
+
+static inline cycles_t get_cycles (void)
+{
+ unsigned long long ret;
+
+ rdtscll(ret);
+ return ret;
+}
+
+
+#endif // _KERNELUTILS_X86_64_H