[PATCH] Clean up read write lock assembly

- Move the slow path fallbacks to their own assembly files
This makes them much easier to read and is needed for the next change.
- Add CFI annotations for unwinding (XXX need review)
- Remove constant case which can never happen with out of line spinlocks
- Use patchable LOCK prefixes
- Don't use lock sections anymore for inline code because they can't
be expressed by the unwinder (this adds one taken jump to the lock
fast path)

Cc: jbeulich@novell.com

Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 0 insertions, 30 deletions

diff --git a/arch/x86_64/lib/thunk.S b/arch/x86_64/lib/thunk.S
index 332ea5dff916..6cff27c775ae 100644
--- a/arch/x86_64/lib/thunk.S
+++ b/arch/x86_64/lib/thunk.S
@@ -67,33 +67,3 @@ restore_norax:
         RESTORE_ARGS 1
         ret
         CFI_ENDPROC
-
-#ifdef CONFIG_SMP
-/* Support for read/write spinlocks. */
-        .text
-/* rax: pointer to rwlock_t */  
-ENTRY(__write_lock_failed)
-        lock
-        addl $RW_LOCK_BIAS,(%rax)
-1:      rep
-        nop
-        cmpl $RW_LOCK_BIAS,(%rax)
-        jne 1b
-        lock 
-        subl $RW_LOCK_BIAS,(%rax)
-        jnz  __write_lock_failed
-        ret
-
-/* rax: pointer to rwlock_t */  
-ENTRY(__read_lock_failed)
-        lock
-        incl (%rax)
-1:      rep
-        nop
-        cmpl $1,(%rax)
-        js 1b
-        lock
-        decl (%rax)
-        js __read_lock_failed
-        ret
-#endif