linux/arch/x86/lib/rwlock_64.S

/* Slow paths of read/write spinlocks. */

#include <linux/linkage.h>
#include <asm/rwlock.h>
#include <asm/alternative-asm.h>
#include <asm/dwarf2.h>

/* rdi:	pointer to rwlock_t */
ENTRY(__write_lock_failed)
	CFI_STARTPROC
	LOCK_PREFIX
	addl $RW_LOCK_BIAS,(%rdi)
1:	rep
	nop
	cmpl $RW_LOCK_BIAS,(%rdi)
	jne 1b
	LOCK_PREFIX
	subl $RW_LOCK_BIAS,(%rdi)
	jnz  __write_lock_failed
	ret
	CFI_ENDPROC
END(__write_lock_failed)

/* rdi:	pointer to rwlock_t */
ENTRY(__read_lock_failed)
	CFI_STARTPROC
	LOCK_PREFIX
	incl (%rdi)
1:	rep
	nop
	cmpl $1,(%rdi)
	js 1b
	LOCK_PREFIX
	decl (%rdi)
	js __read_lock_failed
	ret
	CFI_ENDPROC
END(__read_lock_failed)
[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 16:52:28 +08:00			`/* Slow paths of read/write spinlocks. */`

			`#include <linux/linkage.h>`
			`#include <asm/rwlock.h>`
x86: rename .i assembler includes to .h .i is an ending used for preprocessed stuff. This patch therefore renames assembler include files to .h and guards the contents with an #ifdef __ASSEMBLY__. [ tglx: arch/x86 adaptation ] Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 2007-10-18 00:04:38 +08:00			`#include <asm/alternative-asm.h>`
[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 16:52:28 +08:00			`#include <asm/dwarf2.h>`

			`/* rdi: pointer to rwlock_t */`
			`ENTRY(__write_lock_failed)`
			`CFI_STARTPROC`
			`LOCK_PREFIX`
			`addl $RW_LOCK_BIAS,(%rdi)`
			`1: rep`
			`nop`
			`cmpl $RW_LOCK_BIAS,(%rdi)`
			`jne 1b`
			`LOCK_PREFIX`
			`subl $RW_LOCK_BIAS,(%rdi)`
			`jnz __write_lock_failed`
			`ret`
			`CFI_ENDPROC`
			`END(__write_lock_failed)`

			`/* rdi: pointer to rwlock_t */`
			`ENTRY(__read_lock_failed)`
			`CFI_STARTPROC`
			`LOCK_PREFIX`
			`incl (%rdi)`
			`1: rep`
			`nop`
			`cmpl $1,(%rdi)`
			`js 1b`
			`LOCK_PREFIX`
			`decl (%rdi)`
			`js __read_lock_failed`
			`ret`
			`CFI_ENDPROC`
			`END(__read_lock_failed)`