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linux/arch/x86/lib/thunk_64.S
Matthew Wilcox 64ac24e738 Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility.  Thanks to Peter Zijlstra for fixing the lockdep
warning.  Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 10:42:34 -04:00

67 lines
1.5 KiB
ArmAsm

/*
* Save registers before calling assembly functions. This avoids
* disturbance of register allocation in some inline assembly constructs.
* Copyright 2001,2002 by Andi Kleen, SuSE Labs.
* Subject to the GNU public license, v.2. No warranty of any kind.
*/
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/calling.h>
#include <asm/rwlock.h>
/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
.macro thunk name,func
.globl \name
\name:
CFI_STARTPROC
SAVE_ARGS
call \func
jmp restore
CFI_ENDPROC
.endm
/* rdi: arg1 ... normal C conventions. rax is passed from C. */
.macro thunk_retrax name,func
.globl \name
\name:
CFI_STARTPROC
SAVE_ARGS
call \func
jmp restore_norax
CFI_ENDPROC
.endm
.section .sched.text, "ax"
#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
thunk rwsem_down_read_failed_thunk,rwsem_down_read_failed
thunk rwsem_down_write_failed_thunk,rwsem_down_write_failed
thunk rwsem_wake_thunk,rwsem_wake
thunk rwsem_downgrade_thunk,rwsem_downgrade_wake
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
thunk trace_hardirqs_on_thunk,trace_hardirqs_on
thunk trace_hardirqs_off_thunk,trace_hardirqs_off
#endif
#ifdef CONFIG_DEBUG_LOCK_ALLOC
thunk lockdep_sys_exit_thunk,lockdep_sys_exit
#endif
/* SAVE_ARGS below is used only for the .cfi directives it contains. */
CFI_STARTPROC
SAVE_ARGS
restore:
RESTORE_ARGS
ret
CFI_ENDPROC
CFI_STARTPROC
SAVE_ARGS
restore_norax:
RESTORE_ARGS 1
ret
CFI_ENDPROC