[net-next-2.6.git] / arch / x86 / lib / rwsem_64.S

/*
 * 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)
Commit	Line	Data
bafaecd1 LT	1	/*
	2	* x86-64 rwsem wrappers
	3	*
	4	* This interfaces the inline asm code to the slow-path
	5	* C routines. We need to save the call-clobbered regs
	6	* that the asm does not mark as clobbered, and move the
	7	* argument from %rax to %rdi.
	8	*
	9	* NOTE! We don't need to save %rax, because the functions
	10	* will always return the semaphore pointer in %rax (which
	11	* is also the input argument to these helpers)
	12	*
	13	* The following can clobber %rdx because the asm clobbers it:
	14	* call_rwsem_down_write_failed
	15	* call_rwsem_wake
	16	* but %rdi, %rsi, %rcx, %r8-r11 always need saving.
	17	*/
	18
	19	#include <linux/linkage.h>
	20	#include <asm/rwlock.h>
	21	#include <asm/alternative-asm.h>
	22	#include <asm/frame.h>
	23	#include <asm/dwarf2.h>
	24
	25	#define save_common_regs \
	26	pushq %rdi; \
	27	pushq %rsi; \
	28	pushq %rcx; \
	29	pushq %r8; \
	30	pushq %r9; \
	31	pushq %r10; \
	32	pushq %r11
	33
	34	#define restore_common_regs \
	35	popq %r11; \
	36	popq %r10; \
	37	popq %r9; \
	38	popq %r8; \
	39	popq %rcx; \
	40	popq %rsi; \
	41	popq %rdi
	42
	43	/* Fix up special calling conventions */
	44	ENTRY(call_rwsem_down_read_failed)
	45	save_common_regs
	46	pushq %rdx
	47	movq %rax,%rdi
	48	call rwsem_down_read_failed
	49	popq %rdx
	50	restore_common_regs
	51	ret
	52	ENDPROC(call_rwsem_down_read_failed)
	53
	54	ENTRY(call_rwsem_down_write_failed)
	55	save_common_regs
	56	movq %rax,%rdi
	57	call rwsem_down_write_failed
	58	restore_common_regs
	59	ret
	60	ENDPROC(call_rwsem_down_write_failed)
	61
	62	ENTRY(call_rwsem_wake)
a66f6375	63	decl %edx /* do nothing if still outstanding active readers */
bafaecd1 LT	64	jnz 1f
	65	save_common_regs
	66	movq %rax,%rdi
	67	call rwsem_wake
	68	restore_common_regs
	69	1: ret
	70	ENDPROC(call_rwsem_wake)
	71
	72	/* Fix up special calling conventions */
	73	ENTRY(call_rwsem_downgrade_wake)
	74	save_common_regs
	75	pushq %rdx
	76	movq %rax,%rdi
	77	call rwsem_downgrade_wake
	78	popq %rdx
	79	restore_common_regs
	80	ret
	81	ENDPROC(call_rwsem_downgrade_wake)