1 files changed, 230 insertions, 0 deletions

diff --git a/arch/x86/lib/atomic64_32.c b/arch/x86/lib/atomic64_32.c
new file mode 100644
index 000000000000..824fa0be55a3
--- /dev/null
+++ b/arch/x86/lib/atomic64_32.c
@@ -0,0 +1,230 @@
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include <asm/processor.h>
+#include <asm/cmpxchg.h>
+#include <asm/atomic.h>
+
+static noinline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new)
+{
+        u32 low = new;
+        u32 high = new >> 32;
+
+        asm volatile(
+                LOCK_PREFIX "cmpxchg8b %1\n"
+                     : "+A" (old), "+m" (*ptr)
+                     :  "b" (low),  "c" (high)
+                     );
+        return old;
+}
+
+u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val)
+{
+        return cmpxchg8b(&ptr->counter, old_val, new_val);
+}
+EXPORT_SYMBOL(atomic64_cmpxchg);
+
+/**
+ * atomic64_xchg - xchg atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ * @new_val:  value to assign
+ *
+ * Atomically xchgs the value of @ptr to @new_val and returns
+ * the old value.
+ */
+u64 atomic64_xchg(atomic64_t *ptr, u64 new_val)
+{
+        /*
+         * Try first with a (possibly incorrect) assumption about
+         * what we have there. We'll do two loops most likely,
+         * but we'll get an ownership MESI transaction straight away
+         * instead of a read transaction followed by a
+         * flush-for-ownership transaction:
+         */
+        u64 old_val, real_val = 0;
+
+        do {
+                old_val = real_val;
+
+                real_val = atomic64_cmpxchg(ptr, old_val, new_val);
+
+        } while (real_val != old_val);
+
+        return old_val;
+}
+EXPORT_SYMBOL(atomic64_xchg);
+
+/**
+ * atomic64_set - set atomic64 variable
+ * @ptr:      pointer to type atomic64_t
+ * @new_val:  value to assign
+ *
+ * Atomically sets the value of @ptr to @new_val.
+ */
+void atomic64_set(atomic64_t *ptr, u64 new_val)
+{
+        atomic64_xchg(ptr, new_val);
+}
+EXPORT_SYMBOL(atomic64_set);
+
+/**
+EXPORT_SYMBOL(atomic64_read);
+ * atomic64_add_return - add and return
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns @delta + *@ptr
+ */
+noinline u64 atomic64_add_return(u64 delta, atomic64_t *ptr)
+{
+        /*
+         * Try first with a (possibly incorrect) assumption about
+         * what we have there. We'll do two loops most likely,
+         * but we'll get an ownership MESI transaction straight away
+         * instead of a read transaction followed by a
+         * flush-for-ownership transaction:
+         */
+        u64 old_val, new_val, real_val = 0;
+
+        do {
+                old_val = real_val;
+                new_val = old_val + delta;
+
+                real_val = atomic64_cmpxchg(ptr, old_val, new_val);
+
+        } while (real_val != old_val);
+
+        return new_val;
+}
+EXPORT_SYMBOL(atomic64_add_return);
+
+u64 atomic64_sub_return(u64 delta, atomic64_t *ptr)
+{
+        return atomic64_add_return(-delta, ptr);
+}
+EXPORT_SYMBOL(atomic64_sub_return);
+
+u64 atomic64_inc_return(atomic64_t *ptr)
+{
+        return atomic64_add_return(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_inc_return);
+
+u64 atomic64_dec_return(atomic64_t *ptr)
+{
+        return atomic64_sub_return(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_dec_return);
+
+/**
+ * atomic64_add - add integer to atomic64 variable
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr.
+ */
+void atomic64_add(u64 delta, atomic64_t *ptr)
+{
+        atomic64_add_return(delta, ptr);
+}
+EXPORT_SYMBOL(atomic64_add);
+
+/**
+ * atomic64_sub - subtract the atomic64 variable
+ * @delta: integer value to subtract
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr.
+ */
+void atomic64_sub(u64 delta, atomic64_t *ptr)
+{
+        atomic64_add(-delta, ptr);
+}
+EXPORT_SYMBOL(atomic64_sub);
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @delta: integer value to subtract
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically subtracts @delta from @ptr and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+int atomic64_sub_and_test(u64 delta, atomic64_t *ptr)
+{
+        u64 new_val = atomic64_sub_return(delta, ptr);
+
+        return new_val == 0;
+}
+EXPORT_SYMBOL(atomic64_sub_and_test);
+
+/**
+ * atomic64_inc - increment atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1.
+ */
+void atomic64_inc(atomic64_t *ptr)
+{
+        atomic64_add(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_inc);
+
+/**
+ * atomic64_dec - decrement atomic64 variable
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1.
+ */
+void atomic64_dec(atomic64_t *ptr)
+{
+        atomic64_sub(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_dec);
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically decrements @ptr by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+int atomic64_dec_and_test(atomic64_t *ptr)
+{
+        return atomic64_sub_and_test(1, ptr);
+}
+EXPORT_SYMBOL(atomic64_dec_and_test);
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @ptr: pointer to type atomic64_t
+ *
+ * Atomically increments @ptr by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+int atomic64_inc_and_test(atomic64_t *ptr)
+{
+        return atomic64_sub_and_test(-1, ptr);
+}
+EXPORT_SYMBOL(atomic64_inc_and_test);
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @delta: integer value to add
+ * @ptr:   pointer to type atomic64_t
+ *
+ * Atomically adds @delta to @ptr and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+int atomic64_add_negative(u64 delta, atomic64_t *ptr)
+{
+        s64 new_val = atomic64_add_return(delta, ptr);
+
+        return new_val < 0;
+}
+EXPORT_SYMBOL(atomic64_add_negative);