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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2007-10-12 21:27:47 -0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2007-10-12 21:27:47 -0400
commitb981d8b3f5e008ff10d993be633ad00564fc22cd (patch)
treee292dc07b22308912cf6a58354a608b9e5e8e1fd /arch/x86/lib/rwlock_64.S
parentb11d2127c4893a7315d1e16273bc8560049fa3ca (diff)
parent2b9e0aae1d50e880c58d46788e5e3ebd89d75d62 (diff)
Merge master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts: drivers/macintosh/adbhid.c
Diffstat (limited to 'arch/x86/lib/rwlock_64.S')
-rw-r--r--arch/x86/lib/rwlock_64.S38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/x86/lib/rwlock_64.S b/arch/x86/lib/rwlock_64.S
new file mode 100644
index 00000000000..0cde1f80731
--- /dev/null
+++ b/arch/x86/lib/rwlock_64.S
@@ -0,0 +1,38 @@
+/* Slow paths of read/write spinlocks. */
+
+#include <linux/linkage.h>
+#include <asm/rwlock.h>
+#include <asm/alternative-asm.i>
+#include <asm/dwarf2.h>
+
+/* rdi: pointer to rwlock_t */
+ENTRY(__write_lock_failed)
+ CFI_STARTPROC
+ LOCK_PREFIX
+ addl $RW_LOCK_BIAS,(%rdi)
+1: rep
+ nop
+ cmpl $RW_LOCK_BIAS,(%rdi)
+ jne 1b
+ LOCK_PREFIX
+ subl $RW_LOCK_BIAS,(%rdi)
+ jnz __write_lock_failed
+ ret
+ CFI_ENDPROC
+END(__write_lock_failed)
+
+/* rdi: pointer to rwlock_t */
+ENTRY(__read_lock_failed)
+ CFI_STARTPROC
+ LOCK_PREFIX
+ incl (%rdi)
+1: rep
+ nop
+ cmpl $1,(%rdi)
+ js 1b
+ LOCK_PREFIX
+ decl (%rdi)
+ js __read_lock_failed
+ ret
+ CFI_ENDPROC
+END(__read_lock_failed)