82 lines
1.7 KiB
ArmAsm
82 lines
1.7 KiB
ArmAsm
/*
|
|
* x86-64 rwsem wrappers
|
|
*
|
|
* This interfaces the inline asm code to the slow-path
|
|
* C routines. We need to save the call-clobbered regs
|
|
* that the asm does not mark as clobbered, and move the
|
|
* argument from %rax to %rdi.
|
|
*
|
|
* NOTE! We don't need to save %rax, because the functions
|
|
* will always return the semaphore pointer in %rax (which
|
|
* is also the input argument to these helpers)
|
|
*
|
|
* The following can clobber %rdx because the asm clobbers it:
|
|
* call_rwsem_down_write_failed
|
|
* call_rwsem_wake
|
|
* but %rdi, %rsi, %rcx, %r8-r11 always need saving.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/rwlock.h>
|
|
#include <asm/alternative-asm.h>
|
|
#include <asm/frame.h>
|
|
#include <asm/dwarf2.h>
|
|
|
|
#define save_common_regs \
|
|
pushq %rdi; \
|
|
pushq %rsi; \
|
|
pushq %rcx; \
|
|
pushq %r8; \
|
|
pushq %r9; \
|
|
pushq %r10; \
|
|
pushq %r11
|
|
|
|
#define restore_common_regs \
|
|
popq %r11; \
|
|
popq %r10; \
|
|
popq %r9; \
|
|
popq %r8; \
|
|
popq %rcx; \
|
|
popq %rsi; \
|
|
popq %rdi
|
|
|
|
/* Fix up special calling conventions */
|
|
ENTRY(call_rwsem_down_read_failed)
|
|
save_common_regs
|
|
pushq %rdx
|
|
movq %rax,%rdi
|
|
call rwsem_down_read_failed
|
|
popq %rdx
|
|
restore_common_regs
|
|
ret
|
|
ENDPROC(call_rwsem_down_read_failed)
|
|
|
|
ENTRY(call_rwsem_down_write_failed)
|
|
save_common_regs
|
|
movq %rax,%rdi
|
|
call rwsem_down_write_failed
|
|
restore_common_regs
|
|
ret
|
|
ENDPROC(call_rwsem_down_write_failed)
|
|
|
|
ENTRY(call_rwsem_wake)
|
|
decl %edx /* do nothing if still outstanding active readers */
|
|
jnz 1f
|
|
save_common_regs
|
|
movq %rax,%rdi
|
|
call rwsem_wake
|
|
restore_common_regs
|
|
1: ret
|
|
ENDPROC(call_rwsem_wake)
|
|
|
|
/* Fix up special calling conventions */
|
|
ENTRY(call_rwsem_downgrade_wake)
|
|
save_common_regs
|
|
pushq %rdx
|
|
movq %rax,%rdi
|
|
call rwsem_downgrade_wake
|
|
popq %rdx
|
|
restore_common_regs
|
|
ret
|
|
ENDPROC(call_rwsem_downgrade_wake)
|