1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_FUTEX_H
  3#define _ASM_FUTEX_H
  4
  5#include <linux/futex.h>
  6#include <linux/uaccess.h>
  7#include <asm/errno.h>
  8
  9#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
 10do {									\
 11	register unsigned long r8 __asm ("r8") = 0;			\
 12	__asm__ __volatile__(						\
 13		"	mf;;					\n"	\
 14		"[1:] "	insn ";;				\n"	\
 15		"	.xdata4 \"__ex_table\", 1b-., 2f-.	\n"	\
 16		"[2:]"							\
 17		: "+r" (r8), "=r" (oldval)				\
 18		: "r" (uaddr), "r" (oparg)				\
 19		: "memory");						\
 20	ret = r8;							\
 21} while (0)
 22
 23#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
 24do {									\
 25	register unsigned long r8 __asm ("r8") = 0;			\
 26	int val, newval;						\
 27	do {								\
 28		__asm__ __volatile__(					\
 29			"	mf;;				  \n"	\
 30			"[1:]	ld4 %3=[%4];;			  \n"	\
 31			"	mov %2=%3			  \n"	\
 32				insn	";;			  \n"	\
 33			"	mov ar.ccv=%2;;			  \n"	\
 34			"[2:]	cmpxchg4.acq %1=[%4],%3,ar.ccv;;  \n"	\
 35			"	.xdata4 \"__ex_table\", 1b-., 3f-.\n"	\
 36			"	.xdata4 \"__ex_table\", 2b-., 3f-.\n"	\
 37			"[3:]"						\
 38			: "+r" (r8), "=r" (val), "=&r" (oldval),	\
 39			   "=&r" (newval)				\
 40			: "r" (uaddr), "r" (oparg)			\
 41			: "memory");					\
 42		if (unlikely (r8))					\
 43			break;						\
 44	} while (unlikely (val != oldval));				\
 45	ret = r8;							\
 46} while (0)
 47
 48static inline int
 49arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
 50{
 51	int oldval = 0, ret;
 52
 53	if (!access_ok(uaddr, sizeof(u32)))
 54		return -EFAULT;
 55
 56	switch (op) {
 57	case FUTEX_OP_SET:
 58		__futex_atomic_op1("xchg4 %1=[%2],%3", ret, oldval, uaddr,
 59				   oparg);
 60		break;
 61	case FUTEX_OP_ADD:
 62		__futex_atomic_op2("add %3=%3,%5", ret, oldval, uaddr, oparg);
 63		break;
 64	case FUTEX_OP_OR:
 65		__futex_atomic_op2("or %3=%3,%5", ret, oldval, uaddr, oparg);
 66		break;
 67	case FUTEX_OP_ANDN:
 68		__futex_atomic_op2("and %3=%3,%5", ret, oldval, uaddr,
 69				   ~oparg);
 70		break;
 71	case FUTEX_OP_XOR:
 72		__futex_atomic_op2("xor %3=%3,%5", ret, oldval, uaddr, oparg);
 73		break;
 74	default:
 75		ret = -ENOSYS;
 76	}
 77
 78	if (!ret)
 79		*oval = oldval;
 80
 81	return ret;
 82}
 83
 84static inline int
 85futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 86			      u32 oldval, u32 newval)
 87{
 88	if (!access_ok(uaddr, sizeof(u32)))
 89		return -EFAULT;
 90
 91	{
 92		register unsigned long r8 __asm ("r8") = 0;
 93		unsigned long prev;
 94		__asm__ __volatile__(
 95			"	mf;;					\n"
 96			"	mov ar.ccv=%4;;				\n"
 97			"[1:]	cmpxchg4.acq %1=[%2],%3,ar.ccv		\n"
 98			"	.xdata4 \"__ex_table\", 1b-., 2f-.	\n"
 99			"[2:]"
100			: "+r" (r8), "=&r" (prev)
101			: "r" (uaddr), "r" (newval),
102			  "rO" ((long) (unsigned) oldval)
103			: "memory");
104		*uval = prev;
105		return r8;
106	}
107}
108
109#endif /* _ASM_FUTEX_H */