Commit ebfaebae authored by Ralf Baechle's avatar Ralf Baechle
Browse files

Futexes for MIPS, for the time being only the R10000_LLSC_WAR version. 



Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 9dbdfce8

include/asm-mips/futex.h

+50 −0
Original line number Diff line number Diff line
@@ -3,10 +3,45 @@ 


#ifdef __KERNEL__



#include <linux/config.h>

#include <linux/futex.h>

#include <asm/errno.h>

#include <asm/uaccess.h>



#ifdef CONFIG_SMP

#define __FUTEX_SMP_SYNC "	sync					\n"

#else

#define __FUTEX_SMP_SYNC

#endif



#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)		\

{									\

	__asm__ __volatile__(						\

	"	.set	push					\n"	\

	"	.set	noat					\n"	\

	"	.set	mips3					\n"	\

	"1:	ll	%1, (%3)	# __futex_atomic_op1	\n"	\

	"	.set	mips0					\n"	\

	"	" insn	"					\n"	\

	"	.set	mips3					\n"	\

	"2:	sc	$1, (%3)				\n"	\

	"	beqzl	$1, 1b					\n"	\

	__FUTEX_SMP_SYNC						\

	"3:							\n"	\

	"	.set	pop					\n"	\

	"	.set	mips0					\n"	\

	"	.section .fixup,\"ax\"				\n"	\

	"4:	li	%0, %5					\n"	\

	"	j	2b					\n"	\

	"	.previous					\n"	\

	"	.section __ex_table,\"a\"			\n"	\

	"	"__UA_ADDR "\t1b, 4b				\n"	\

	"	"__UA_ADDR "\t2b, 4b				\n"	\

	"	.previous					\n"	\

	: "=r" (ret), "=r" (oldval)					\

	: "0" (0), "r" (uaddr), "Jr" (oparg), "i" (-EFAULT));		\

}



static inline int

futex_atomic_op_inuser (int encoded_op, int __user *uaddr)

{
@@ -25,10 +60,25 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) 


	switch (op) {

	case FUTEX_OP_SET:

		__futex_atomic_op("move	$1, %z4", ret, oldval, uaddr, oparg);

		break;



	case FUTEX_OP_ADD:

		__futex_atomic_op("addu	$1, %1, %z4",

		                  ret, oldval, uaddr, oparg);

		break;

	case FUTEX_OP_OR:

		__futex_atomic_op("or	$1, %1, %z4",

		                  ret, oldval, uaddr, oparg);

		break;

	case FUTEX_OP_ANDN:

		__futex_atomic_op("and	$1, %1, %z4",

		                  ret, oldval, uaddr, ~oparg);

		break;

	case FUTEX_OP_XOR:

		__futex_atomic_op("xor	$1, %1, %z4",

		                  ret, oldval, uaddr, oparg);

		break;

	default:

		ret = -ENOSYS;

	}