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!
diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h
new file mode 100644
index 0000000..2885972
--- /dev/null
+++ b/include/asm-arm/atomic.h
@@ -0,0 +1,165 @@
+/*
+ * linux/include/asm-arm/atomic.h
+ *
+ * Copyright (C) 1996 Russell King.
+ * Copyright (C) 2002 Deep Blue Solutions Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __ASM_ARM_ATOMIC_H
+#define __ASM_ARM_ATOMIC_H
+
+#include <linux/config.h>
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i) { (i) }
+
+#ifdef __KERNEL__
+
+#define atomic_read(v) ((v)->counter)
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+/*
+ * ARMv6 UP and SMP safe atomic ops. We use load exclusive and
+ * store exclusive to ensure that these are atomic. We may loop
+ * to ensure that the update happens. Writing to 'v->counter'
+ * without using the following operations WILL break the atomic
+ * nature of these ops.
+ */
+static inline void atomic_set(atomic_t *v, int i)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__("@ atomic_set\n"
+"1: ldrex %0, [%1]\n"
+" strex %0, %2, [%1]\n"
+" teq %0, #0\n"
+" bne 1b"
+ : "=&r" (tmp)
+ : "r" (&v->counter), "r" (i)
+ : "cc");
+}
+
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+ unsigned long tmp;
+ int result;
+
+ __asm__ __volatile__("@ atomic_add_return\n"
+"1: ldrex %0, [%2]\n"
+" add %0, %0, %3\n"
+" strex %1, %0, [%2]\n"
+" teq %1, #0\n"
+" bne 1b"
+ : "=&r" (result), "=&r" (tmp)
+ : "r" (&v->counter), "Ir" (i)
+ : "cc");
+
+ return result;
+}
+
+static inline int atomic_sub_return(int i, atomic_t *v)
+{
+ unsigned long tmp;
+ int result;
+
+ __asm__ __volatile__("@ atomic_sub_return\n"
+"1: ldrex %0, [%2]\n"
+" sub %0, %0, %3\n"
+" strex %1, %0, [%2]\n"
+" teq %1, #0\n"
+" bne 1b"
+ : "=&r" (result), "=&r" (tmp)
+ : "r" (&v->counter), "Ir" (i)
+ : "cc");
+
+ return result;
+}
+
+static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+{
+ unsigned long tmp, tmp2;
+
+ __asm__ __volatile__("@ atomic_clear_mask\n"
+"1: ldrex %0, %2\n"
+" bic %0, %0, %3\n"
+" strex %1, %0, %2\n"
+" teq %1, #0\n"
+" bne 1b"
+ : "=&r" (tmp), "=&r" (tmp2)
+ : "r" (addr), "Ir" (mask)
+ : "cc");
+}
+
+#else /* ARM_ARCH_6 */
+
+#include <asm/system.h>
+
+#ifdef CONFIG_SMP
+#error SMP not supported on pre-ARMv6 CPUs
+#endif
+
+#define atomic_set(v,i) (((v)->counter) = (i))
+
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+ unsigned long flags;
+ int val;
+
+ local_irq_save(flags);
+ val = v->counter;
+ v->counter = val += i;
+ local_irq_restore(flags);
+
+ return val;
+}
+
+static inline int atomic_sub_return(int i, atomic_t *v)
+{
+ unsigned long flags;
+ int val;
+
+ local_irq_save(flags);
+ val = v->counter;
+ v->counter = val -= i;
+ local_irq_restore(flags);
+
+ return val;
+}
+
+static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *addr &= ~mask;
+ local_irq_restore(flags);
+}
+
+#endif /* __LINUX_ARM_ARCH__ */
+
+#define atomic_add(i, v) (void) atomic_add_return(i, v)
+#define atomic_inc(v) (void) atomic_add_return(1, v)
+#define atomic_sub(i, v) (void) atomic_sub_return(i, v)
+#define atomic_dec(v) (void) atomic_sub_return(1, v)
+
+#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
+#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
+#define atomic_inc_return(v) (atomic_add_return(1, v))
+#define atomic_dec_return(v) (atomic_sub_return(1, v))
+#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
+
+#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
+
+/* Atomic operations are already serializing on ARM */
+#define smp_mb__before_atomic_dec() barrier()
+#define smp_mb__after_atomic_dec() barrier()
+#define smp_mb__before_atomic_inc() barrier()
+#define smp_mb__after_atomic_inc() barrier()
+
+#endif
+#endif