android_kernel_xiaomi_sm8350/arch/x86_64/lib/thunk.S
Andi Kleen 9a0b26e6bc [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>
2006-09-26 10:52:28 +02:00

70 lines
1.6 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.
* $Id: thunk.S,v 1.2 2002/03/13 20:06:58 ak Exp $
*/
#include <linux/config.h>
#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
#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
thunk __down_failed,__down
thunk_retrax __down_failed_interruptible,__down_interruptible
thunk_retrax __down_failed_trylock,__down_trylock
thunk __up_wakeup,__up
#ifdef CONFIG_TRACE_IRQFLAGS
thunk trace_hardirqs_on_thunk,trace_hardirqs_on
thunk trace_hardirqs_off_thunk,trace_hardirqs_off
#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