[mirror_ubuntu-focal-kernel.git] / arch / xtensa / include / asm / futex.h

/*
 * Atomic futex routines
 *
 * Based on the PowerPC implementataion
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Copyright (C) 2013 TangoTec Ltd.
 *
 * Baruch Siach <baruch@tkos.co.il>
 */

#ifndef _ASM_XTENSA_FUTEX_H
#define _ASM_XTENSA_FUTEX_H

#ifdef __KERNEL__

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <linux/errno.h>

#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
	__asm__ __volatile(				\
	"1:	l32i	%0, %2, 0\n"			\
		insn "\n"				\
	"	wsr	%0, scompare1\n"		\
	"2:	s32c1i	%1, %2, 0\n"			\
	"	bne	%1, %0, 1b\n"			\
	"	movi	%1, 0\n"			\
	"3:\n"						\
	"	.section .fixup,\"ax\"\n"		\
	"	.align 4\n"				\
	"	.literal_position\n"			\
	"5:	movi	%0, 3b\n"			\
	"	movi	%1, %3\n"			\
	"	jx	%0\n"				\
	"	.previous\n"				\
	"	.section __ex_table,\"a\"\n"		\
	"	.long 1b,5b,2b,5b\n"			\
	"	.previous\n"				\
	: "=&r" (oldval), "=&r" (ret)			\
	: "r" (uaddr), "I" (-EFAULT), "r" (oparg)	\
	: "memory")

static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
		u32 __user *uaddr)
{
	int oldval = 0, ret;

#if !XCHAL_HAVE_S32C1I
	return -ENOSYS;
#endif

	pagefault_disable();

	switch (op) {
	case FUTEX_OP_SET:
		__futex_atomic_op("mov %1, %4", ret, oldval, uaddr, oparg);
		break;
	case FUTEX_OP_ADD:
		__futex_atomic_op("add %1, %0, %4", ret, oldval, uaddr,
				oparg);
		break;
	case FUTEX_OP_OR:
		__futex_atomic_op("or %1, %0, %4", ret, oldval, uaddr,
				oparg);
		break;
	case FUTEX_OP_ANDN:
		__futex_atomic_op("and %1, %0, %4", ret, oldval, uaddr,
				~oparg);
		break;
	case FUTEX_OP_XOR:
		__futex_atomic_op("xor %1, %0, %4", ret, oldval, uaddr,
				oparg);
		break;
	default:
		ret = -ENOSYS;
	}

	pagefault_enable();

	if (!ret)
		*oval = oldval;

	return ret;
}

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
			      u32 oldval, u32 newval)
{
	int ret = 0;

	if (!access_ok(uaddr, sizeof(u32)))
		return -EFAULT;

#if !XCHAL_HAVE_S32C1I
	return -ENOSYS;
#endif

	__asm__ __volatile__ (
	"	# futex_atomic_cmpxchg_inatomic\n"
	"	wsr	%5, scompare1\n"
	"1:	s32c1i	%1, %4, 0\n"
	"	s32i	%1, %6, 0\n"
	"2:\n"
	"	.section .fixup,\"ax\"\n"
	"	.align 4\n"
	"	.literal_position\n"
	"4:	movi	%1, 2b\n"
	"	movi	%0, %7\n"
	"	jx	%1\n"
	"	.previous\n"
	"	.section __ex_table,\"a\"\n"
	"	.long 1b,4b\n"
	"	.previous\n"
	: "+r" (ret), "+r" (newval), "+m" (*uaddr), "+m" (*uval)
	: "r" (uaddr), "r" (oldval), "r" (uval), "I" (-EFAULT)
	: "memory");

	return ret;
}

#endif /* __KERNEL__ */
#endif /* _ASM_XTENSA_FUTEX_H */
Commit	Line	Data
220c0626 BS	1	/*
	2	* Atomic futex routines
	3	*
	4	* Based on the PowerPC implementataion
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* Copyright (C) 2013 TangoTec Ltd.
	11	*
	12	* Baruch Siach <baruch@tkos.co.il>
	13	*/
	14
	15	#ifndef _ASM_XTENSA_FUTEX_H
	16	#define _ASM_XTENSA_FUTEX_H
	17
	18	#ifdef __KERNEL__
	19
	20	#include <linux/futex.h>
	21	#include <linux/uaccess.h>
	22	#include <linux/errno.h>
	23
	24	#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
	25	__asm__ __volatile( \
	26	"1: l32i %0, %2, 0\n" \
	27	insn "\n" \
	28	" wsr %0, scompare1\n" \
	29	"2: s32c1i %1, %2, 0\n" \
	30	" bne %1, %0, 1b\n" \
	31	" movi %1, 0\n" \
	32	"3:\n" \
	33	" .section .fixup,\"ax\"\n" \
	34	" .align 4\n" \
03760270 MF	35	" .literal_position\n" \
03760270 MF	36	"5: movi %0, 3b\n" \
220c0626 BS	37	" movi %1, %3\n" \
	38	" jx %0\n" \
	39	" .previous\n" \
	40	" .section __ex_table,\"a\"\n" \
	41	" .long 1b,5b,2b,5b\n" \
	42	" .previous\n" \
	43	: "=&r" (oldval), "=&r" (ret) \
	44	: "r" (uaddr), "I" (-EFAULT), "r" (oparg) \
	45	: "memory")
	46
30d6e0a4 JS	47	static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
30d6e0a4 JS	48	u32 __user *uaddr)
220c0626	49	{
220c0626	50	int oldval = 0, ret;
220c0626 BS	51
	52	#if !XCHAL_HAVE_S32C1I
	53	return -ENOSYS;
	54	#endif
	55
	56	pagefault_disable();
	57
	58	switch (op) {
	59	case FUTEX_OP_SET:
	60	__futex_atomic_op("mov %1, %4", ret, oldval, uaddr, oparg);
	61	break;
	62	case FUTEX_OP_ADD:
	63	__futex_atomic_op("add %1, %0, %4", ret, oldval, uaddr,
	64	oparg);
	65	break;
	66	case FUTEX_OP_OR:
	67	__futex_atomic_op("or %1, %0, %4", ret, oldval, uaddr,
	68	oparg);
	69	break;
	70	case FUTEX_OP_ANDN:
	71	__futex_atomic_op("and %1, %0, %4", ret, oldval, uaddr,
	72	~oparg);
	73	break;
	74	case FUTEX_OP_XOR:
	75	__futex_atomic_op("xor %1, %0, %4", ret, oldval, uaddr,
	76	oparg);
	77	break;
	78	default:
	79	ret = -ENOSYS;
	80	}
	81
	82	pagefault_enable();
	83
30d6e0a4 JS	84	if (!ret)
30d6e0a4 JS	85	*oval = oldval;
220c0626	86
30d6e0a4	87	return ret;
220c0626 BS	88	}
	89
	90	static inline int
	91	futex_atomic_cmpxchg_inatomic(u32 uval, u32 __user uaddr,
	92	u32 oldval, u32 newval)
	93	{
	94	int ret = 0;
220c0626	95
96d4f267	96	if (!access_ok(uaddr, sizeof(u32)))
220c0626 BS	97	return -EFAULT;
	98
	99	#if !XCHAL_HAVE_S32C1I
	100	return -ENOSYS;
	101	#endif
	102
	103	__asm__ __volatile__ (
	104	" # futex_atomic_cmpxchg_inatomic\n"
ca474809 MF	105	" wsr %5, scompare1\n"
	106	"1: s32c1i %1, %4, 0\n"
	107	" s32i %1, %6, 0\n"
	108	"2:\n"
220c0626 BS	109	" .section .fixup,\"ax\"\n"
220c0626 BS	110	" .align 4\n"
03760270 MF	111	" .literal_position\n"
03760270 MF	112	"4: movi %1, 2b\n"
ca474809	113	" movi %0, %7\n"
220c0626 BS	114	" jx %1\n"
	115	" .previous\n"
	116	" .section __ex_table,\"a\"\n"
ca474809	117	" .long 1b,4b\n"
220c0626	118	" .previous\n"
ca474809 MF	119	: "+r" (ret), "+r" (newval), "+m" (uaddr), "+m" (uval)
ca474809 MF	120	: "r" (uaddr), "r" (oldval), "r" (uval), "I" (-EFAULT)
220c0626 BS	121	: "memory");
220c0626 BS	122
220c0626 BS	123	return ret;
	124	}
	125
	126	#endif /* __KERNEL__ */
	127	#endif /* _ASM_XTENSA_FUTEX_H */