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-rw-r--r--arch/i386/lib/Makefile2
-rw-r--r--arch/i386/lib/semaphore.S154
2 files changed, 155 insertions, 1 deletions
diff --git a/arch/i386/lib/Makefile b/arch/i386/lib/Makefile
index 914933e9ec3..d86a548b8d5 100644
--- a/arch/i386/lib/Makefile
+++ b/arch/i386/lib/Makefile
@@ -4,6 +4,6 @@
lib-y = checksum.o delay.o usercopy.o getuser.o putuser.o memcpy.o strstr.o \
- bitops.o
+ bitops.o semaphore.o
lib-$(CONFIG_X86_USE_3DNOW) += mmx.o
diff --git a/arch/i386/lib/semaphore.S b/arch/i386/lib/semaphore.S
new file mode 100644
index 00000000000..e16ff169639
--- /dev/null
+++ b/arch/i386/lib/semaphore.S
@@ -0,0 +1,154 @@
+/*
+ * i386 semaphore implementation.
+ *
+ * (C) Copyright 1999 Linus Torvalds
+ *
+ * Portions Copyright 1999 Red Hat, Inc.
+ *
+ * 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.
+ *
+ * rw semaphores implemented November 1999 by Benjamin LaHaise <bcrl@kvack.org>
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <asm/rwlock.h>
+#include <asm/alternative-asm.i>
+#include <asm/frame.i>
+#include <asm/dwarf2.h>
+
+/*
+ * The semaphore operations have a special calling sequence that
+ * allow us to do a simpler in-line version of them. These routines
+ * need to convert that sequence back into the C sequence when
+ * there is contention on the semaphore.
+ *
+ * %eax contains the semaphore pointer on entry. Save the C-clobbered
+ * registers (%eax, %edx and %ecx) except %eax whish is either a return
+ * value or just clobbered..
+ */
+ .section .sched.text
+ENTRY(__down_failed)
+ CFI_STARTPROC
+ FRAME
+ pushl %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ pushl %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ call __down
+ popl %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ecx
+ popl %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE edx
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ END(__down_failed)
+
+ENTRY(__down_failed_interruptible)
+ CFI_STARTPROC
+ FRAME
+ pushl %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ pushl %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ call __down_interruptible
+ popl %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ecx
+ popl %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE edx
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ END(__down_failed_interruptible)
+
+ENTRY(__down_failed_trylock)
+ CFI_STARTPROC
+ FRAME
+ pushl %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ pushl %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ call __down_trylock
+ popl %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ecx
+ popl %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE edx
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ END(__down_failed_trylock)
+
+ENTRY(__up_wakeup)
+ CFI_STARTPROC
+ FRAME
+ pushl %edx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET edx,0
+ pushl %ecx
+ CFI_ADJUST_CFA_OFFSET 4
+ CFI_REL_OFFSET ecx,0
+ call __up
+ popl %ecx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE ecx
+ popl %edx
+ CFI_ADJUST_CFA_OFFSET -4
+ CFI_RESTORE edx
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ END(__up_wakeup)
+
+/*
+ * rw spinlock fallbacks
+ */
+#ifdef CONFIG_SMP
+ENTRY(__write_lock_failed)
+ CFI_STARTPROC simple
+ FRAME
+2: LOCK_PREFIX
+ addl $ RW_LOCK_BIAS,(%eax)
+1: rep; nop
+ cmpl $ RW_LOCK_BIAS,(%eax)
+ jne 1b
+ LOCK_PREFIX
+ subl $ RW_LOCK_BIAS,(%eax)
+ jnz 2b
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ END(__write_lock_failed)
+
+ENTRY(__read_lock_failed)
+ CFI_STARTPROC
+ FRAME
+2: LOCK_PREFIX
+ incl (%eax)
+1: rep; nop
+ cmpl $1,(%eax)
+ js 1b
+ LOCK_PREFIX
+ decl (%eax)
+ js 2b
+ ENDFRAME
+ ret
+ CFI_ENDPROC
+ END(__read_lock_failed)
+
+#endif