openwrt/package/mac80211/patches/022-atomic64_backport.patch

--- a/compat/Makefile
+++ b/compat/Makefile
@@ -34,3 +34,8 @@ compat-$(CONFIG_COMPAT_KERNEL_2_6_39) +=
 	compat-2.6.39.o \
 	kstrtox.o
 
+ifndef CONFIG_64BIT
+ifndef CONFIG_GENERIC_ATOMIC64
+  compat-y += compat_atomic.o
+endif
+endif
--- a/include/linux/compat-2.6.31.h
+++ b/include/linux/compat-2.6.31.h
@@ -199,6 +199,20 @@ void compat_synchronize_threaded_irq(str
 #define list_entry_rcu(ptr, type, member) \
 	container_of(rcu_dereference(ptr), type, member)
 
+#ifndef CONFIG_64BIT
+
+typedef struct {
+	long long counter;
+} atomic64_t;
+
+extern long long atomic64_read(const atomic64_t *v);
+extern long long atomic64_add_return(long long a, atomic64_t *v);
+
+#define atomic64_inc_return(v)          atomic64_add_return(1LL, (v))
+
+#endif
+
+
 #endif /* (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,31)) */
 
 #endif /* LINUX_26_31_COMPAT_H */
--- /dev/null
+++ b/compat/compat_atomic.c
@@ -0,0 +1,33 @@
+#include <linux/spinlock.h>
+#include <linux/module.h>
+
+#if !defined(CONFIG_X86) && !((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)) && defined(CONFIG_ARM) && !defined(CONFIG_GENERIC_ATOMIC64))
+
+static DEFINE_SPINLOCK(lock);
+
+long long atomic64_read(const atomic64_t *v)
+{
+    unsigned long flags;
+    long long val;
+
+    spin_lock_irqsave(&lock, flags);
+    val = v->counter;
+    spin_unlock_irqrestore(&lock, flags);
+    return val;
+}
+EXPORT_SYMBOL(atomic64_read);
+
+long long atomic64_add_return(long long a, atomic64_t *v)
+{
+    unsigned long flags;
+    long long val;
+
+    spin_lock_irqsave(&lock, flags);
+    val = v->counter += a;
+    spin_unlock_irqrestore(&lock, flags);
+    return val;
+}
+EXPORT_SYMBOL(atomic64_add_return);
+
+#endif
+
--- a/include/linux/compat-3.1.h
+++ b/include/linux/compat-3.1.h
@@ -24,6 +24,18 @@
 
 #define genl_dump_check_consistent(...) do {} while(0)
 
+/*
+ * In many versions, several architectures do not seem to include an
+ * atomic64_t implementation, and do not include the software emulation from
+ * asm-generic/atomic64_t.
+ * Detect and handle this here.
+ */
+#include <asm/atomic.h>
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,31)) && !defined(ATOMIC64_INIT) && !defined(CONFIG_X86) && !((LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)) && defined(CONFIG_ARM) && !defined(CONFIG_GENERIC_ATOMIC64))
+#include <asm-generic/atomic64.h>
+#endif
+
 #endif /* (LINUX_VERSION_CODE < KERNEL_VERSION(3,1,0)) */
 
 #endif /* LINUX_3_1_COMPAT_H */