• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* SPDX-License-Identifier: GPL-2.0 */
2 // Copyright (C) 2005-2017 Andes Technology Corporation
3 
4 #ifndef __NDS32_FUTEX_H__
5 #define __NDS32_FUTEX_H__
6 
7 #include <linux/futex.h>
8 #include <linux/uaccess.h>
9 #include <asm/errno.h>
10 
11 #define __futex_atomic_ex_table(err_reg)			\
12 	"	.pushsection __ex_table,\"a\"\n"		\
13 	"	.align	3\n"					\
14 	"	.long	1b, 4f\n"				\
15 	"	.long	2b, 4f\n"				\
16 	"	.popsection\n"					\
17 	"	.pushsection .fixup,\"ax\"\n"			\
18 	"4:	move	%0, " err_reg "\n"			\
19 	"	b	3b\n"					\
20 	"	.popsection"
21 
22 #define __futex_atomic_op(insn, ret, oldval, tmp, uaddr, oparg)	\
23 	smp_mb();						\
24 	asm volatile(					\
25 	"	movi	$ta, #0\n"				\
26 	"1:	llw	%1, [%2+$ta]\n"				\
27 	"	" insn "\n"					\
28 	"2:	scw	%0, [%2+$ta]\n"				\
29 	"	beqz	%0, 1b\n"				\
30 	"	movi	%0, #0\n"				\
31 	"3:\n"							\
32 	__futex_atomic_ex_table("%4")				\
33 	: "=&r" (ret), "=&r" (oldval)				\
34 	: "r" (uaddr), "r" (oparg), "i" (-EFAULT)		\
35 	: "cc", "memory")
36 static inline int
futex_atomic_cmpxchg_inatomic(u32 * uval,u32 __user * uaddr,u32 oldval,u32 newval)37 futex_atomic_cmpxchg_inatomic(u32 * uval, u32 __user * uaddr,
38 			      u32 oldval, u32 newval)
39 {
40 	int ret = 0;
41 	u32 val, tmp, flags;
42 
43 	if (!access_ok(uaddr, sizeof(u32)))
44 		return -EFAULT;
45 
46 	smp_mb();
47 	asm volatile ("       movi    $ta, #0\n"
48 		      "1:     llw     %1, [%6 + $ta]\n"
49 		      "       sub     %3, %1, %4\n"
50 		      "       cmovz   %2, %5, %3\n"
51 		      "       cmovn   %2, %1, %3\n"
52 		      "2:     scw     %2, [%6 + $ta]\n"
53 		      "       beqz    %2, 1b\n"
54 		      "3:\n                   " __futex_atomic_ex_table("%7")
55 		      :"+&r"(ret), "=&r"(val), "=&r"(tmp), "=&r"(flags)
56 		      :"r"(oldval), "r"(newval), "r"(uaddr), "i"(-EFAULT)
57 		      :"$ta", "memory");
58 	smp_mb();
59 
60 	*uval = val;
61 	return ret;
62 }
63 
64 static inline int
arch_futex_atomic_op_inuser(int op,int oparg,int * oval,u32 __user * uaddr)65 arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
66 {
67 	int oldval = 0, ret;
68 
69 	if (!access_ok(uaddr, sizeof(u32)))
70 		return -EFAULT;
71 	switch (op) {
72 	case FUTEX_OP_SET:
73 		__futex_atomic_op("move	%0, %3", ret, oldval, tmp, uaddr,
74 				  oparg);
75 		break;
76 	case FUTEX_OP_ADD:
77 		__futex_atomic_op("add	%0, %1, %3", ret, oldval, tmp, uaddr,
78 				  oparg);
79 		break;
80 	case FUTEX_OP_OR:
81 		__futex_atomic_op("or	%0, %1, %3", ret, oldval, tmp, uaddr,
82 				  oparg);
83 		break;
84 	case FUTEX_OP_ANDN:
85 		__futex_atomic_op("and	%0, %1, %3", ret, oldval, tmp, uaddr,
86 				  ~oparg);
87 		break;
88 	case FUTEX_OP_XOR:
89 		__futex_atomic_op("xor	%0, %1, %3", ret, oldval, tmp, uaddr,
90 				  oparg);
91 		break;
92 	default:
93 		ret = -ENOSYS;
94 	}
95 
96 	if (!ret)
97 		*oval = oldval;
98 
99 	return ret;
100 }
101 #endif /* __NDS32_FUTEX_H__ */
102