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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Richard Kuo8feca0e2011-10-31 18:27:03 -05002#ifndef _ASM_HEXAGON_FUTEX_H
3#define _ASM_HEXAGON_FUTEX_H
4
5#ifdef __KERNEL__
6
7#include <linux/futex.h>
8#include <linux/uaccess.h>
9#include <asm/errno.h>
10
11/* XXX TODO-- need to add sync barriers! */
12
13#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
14 __asm__ __volatile( \
15 "1: %0 = memw_locked(%3);\n" \
16 /* For example: %1 = %4 */ \
17 insn \
18 "2: memw_locked(%3,p2) = %1;\n" \
Nick Desaulniers780a0cf2020-01-04 12:59:59 -080019 " if (!p2) jump 1b;\n" \
Richard Kuo8feca0e2011-10-31 18:27:03 -050020 " %1 = #0;\n" \
21 "3:\n" \
22 ".section .fixup,\"ax\"\n" \
23 "4: %1 = #%5;\n" \
Sid Manning6fff7412021-04-26 13:51:53 -050024 " jump ##3b\n" \
Richard Kuo8feca0e2011-10-31 18:27:03 -050025 ".previous\n" \
26 ".section __ex_table,\"a\"\n" \
27 ".long 1b,4b,2b,4b\n" \
28 ".previous\n" \
29 : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr) \
30 : "r" (uaddr), "r" (oparg), "i" (-EFAULT) \
31 : "p2", "memory")
32
33
34static inline int
Jiri Slaby30d6e0a2017-08-24 09:31:05 +020035arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
Richard Kuo8feca0e2011-10-31 18:27:03 -050036{
Richard Kuo8feca0e2011-10-31 18:27:03 -050037 int oldval = 0, ret;
Richard Kuo8feca0e2011-10-31 18:27:03 -050038
Al Viroa08971e2020-02-16 10:17:27 -050039 if (!access_ok(uaddr, sizeof(u32)))
40 return -EFAULT;
Richard Kuo8feca0e2011-10-31 18:27:03 -050041
42 switch (op) {
43 case FUTEX_OP_SET:
44 __futex_atomic_op("%1 = %4\n", ret, oldval, uaddr, oparg);
45 break;
46 case FUTEX_OP_ADD:
47 __futex_atomic_op("%1 = add(%0,%4)\n", ret, oldval, uaddr,
48 oparg);
49 break;
50 case FUTEX_OP_OR:
51 __futex_atomic_op("%1 = or(%0,%4)\n", ret, oldval, uaddr,
52 oparg);
53 break;
54 case FUTEX_OP_ANDN:
55 __futex_atomic_op("%1 = not(%4); %1 = and(%0,%1)\n", ret,
56 oldval, uaddr, oparg);
57 break;
58 case FUTEX_OP_XOR:
59 __futex_atomic_op("%1 = xor(%0,%4)\n", ret, oldval, uaddr,
60 oparg);
61 break;
62 default:
63 ret = -ENOSYS;
64 }
65
Jiri Slaby30d6e0a2017-08-24 09:31:05 +020066 if (!ret)
67 *oval = oldval;
68
Richard Kuo8feca0e2011-10-31 18:27:03 -050069 return ret;
70}
71
72static inline int
73futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
74 u32 newval)
75{
76 int prev;
77 int ret;
78
Linus Torvalds96d4f262019-01-03 18:57:57 -080079 if (!access_ok(uaddr, sizeof(u32)))
Richard Kuo8feca0e2011-10-31 18:27:03 -050080 return -EFAULT;
81
82 __asm__ __volatile__ (
83 "1: %1 = memw_locked(%3)\n"
84 " {\n"
85 " p2 = cmp.eq(%1,%4)\n"
Nick Desaulniers780a0cf2020-01-04 12:59:59 -080086 " if (!p2.new) jump:NT 3f\n"
Richard Kuo8feca0e2011-10-31 18:27:03 -050087 " }\n"
88 "2: memw_locked(%3,p2) = %5\n"
Nick Desaulniers780a0cf2020-01-04 12:59:59 -080089 " if (!p2) jump 1b\n"
Richard Kuo8feca0e2011-10-31 18:27:03 -050090 "3:\n"
91 ".section .fixup,\"ax\"\n"
92 "4: %0 = #%6\n"
Sid Manning6fff7412021-04-26 13:51:53 -050093 " jump ##3b\n"
Richard Kuo8feca0e2011-10-31 18:27:03 -050094 ".previous\n"
95 ".section __ex_table,\"a\"\n"
96 ".long 1b,4b,2b,4b\n"
97 ".previous\n"
98 : "+r" (ret), "=&r" (prev), "+m" (*uaddr)
99 : "r" (uaddr), "r" (oldval), "r" (newval), "i"(-EFAULT)
100 : "p2", "memory");
101
102 *uval = prev;
103 return ret;
104}
105
106#endif /* __KERNEL__ */
107#endif /* _ASM_HEXAGON_FUTEX_H */