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-i386/rwlock.h b/include/asm-i386/rwlock.h
new file mode 100644
index 0000000..b57cc7a
--- /dev/null
+++ b/include/asm-i386/rwlock.h
@@ -0,0 +1,71 @@
+/* include/asm-i386/rwlock.h
+ *
+ * Helpers used by both rw spinlocks and rw semaphores.
+ *
+ * Based in part on code from semaphore.h and
+ * spinlock.h Copyright 1996 Linus Torvalds.
+ *
+ * Copyright 1999 Red Hat, Inc.
+ *
+ * Written by Benjamin LaHaise.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef _ASM_I386_RWLOCK_H
+#define _ASM_I386_RWLOCK_H
+
+#define RW_LOCK_BIAS 0x01000000
+#define RW_LOCK_BIAS_STR "0x01000000"
+
+#define __build_read_lock_ptr(rw, helper) \
+ asm volatile(LOCK "subl $1,(%0)\n\t" \
+ "jns 1f\n" \
+ "call " helper "\n\t" \
+ "1:\n" \
+ ::"a" (rw) : "memory")
+
+#define __build_read_lock_const(rw, helper) \
+ asm volatile(LOCK "subl $1,%0\n\t" \
+ "jns 1f\n" \
+ "pushl %%eax\n\t" \
+ "leal %0,%%eax\n\t" \
+ "call " helper "\n\t" \
+ "popl %%eax\n\t" \
+ "1:\n" \
+ :"=m" (*(volatile int *)rw) : : "memory")
+
+#define __build_read_lock(rw, helper) do { \
+ if (__builtin_constant_p(rw)) \
+ __build_read_lock_const(rw, helper); \
+ else \
+ __build_read_lock_ptr(rw, helper); \
+ } while (0)
+
+#define __build_write_lock_ptr(rw, helper) \
+ asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
+ "jz 1f\n" \
+ "call " helper "\n\t" \
+ "1:\n" \
+ ::"a" (rw) : "memory")
+
+#define __build_write_lock_const(rw, helper) \
+ asm volatile(LOCK "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \
+ "jz 1f\n" \
+ "pushl %%eax\n\t" \
+ "leal %0,%%eax\n\t" \
+ "call " helper "\n\t" \
+ "popl %%eax\n\t" \
+ "1:\n" \
+ :"=m" (*(volatile int *)rw) : : "memory")
+
+#define __build_write_lock(rw, helper) do { \
+ if (__builtin_constant_p(rw)) \
+ __build_write_lock_const(rw, helper); \
+ else \
+ __build_write_lock_ptr(rw, helper); \
+ } while (0)
+
+#endif