1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Atomic futex routines 4 * 5 * Based on the PowerPC implementataion 6 * 7 * Copyright (C) 2013 TangoTec Ltd. 8 * 9 * Baruch Siach <baruch@tkos.co.il> 10 */ 11 12 #ifndef _ASM_XTENSA_FUTEX_H 13 #define _ASM_XTENSA_FUTEX_H 14 15 #include <linux/futex.h> 16 #include <linux/uaccess.h> 17 #include <linux/errno.h> 18 19 #if XCHAL_HAVE_EXCLUSIVE 20 #define __futex_atomic_op(insn, ret, old, uaddr, arg) \ 21 __asm__ __volatile( \ 22 "1: l32ex %[oldval], %[addr]\n" \ 23 insn "\n" \ 24 "2: s32ex %[newval], %[addr]\n" \ 25 " getex %[newval]\n" \ 26 " beqz %[newval], 1b\n" \ 27 " movi %[newval], 0\n" \ 28 "3:\n" \ 29 " .section .fixup,\"ax\"\n" \ 30 " .align 4\n" \ 31 " .literal_position\n" \ 32 "5: movi %[oldval], 3b\n" \ 33 " movi %[newval], %[fault]\n" \ 34 " jx %[oldval]\n" \ 35 " .previous\n" \ 36 " .section __ex_table,\"a\"\n" \ 37 " .long 1b, 5b, 2b, 5b\n" \ 38 " .previous\n" \ 39 : [oldval] "=&r" (old), [newval] "=&r" (ret) \ 40 : [addr] "r" (uaddr), [oparg] "r" (arg), \ 41 [fault] "I" (-EFAULT) \ 42 : "memory") 43 #elif XCHAL_HAVE_S32C1I 44 #define __futex_atomic_op(insn, ret, old, uaddr, arg) \ 45 __asm__ __volatile( \ 46 "1: l32i %[oldval], %[mem]\n" \ 47 insn "\n" \ 48 " wsr %[oldval], scompare1\n" \ 49 "2: s32c1i %[newval], %[mem]\n" \ 50 " bne %[newval], %[oldval], 1b\n" \ 51 " movi %[newval], 0\n" \ 52 "3:\n" \ 53 " .section .fixup,\"ax\"\n" \ 54 " .align 4\n" \ 55 " .literal_position\n" \ 56 "5: movi %[oldval], 3b\n" \ 57 " movi %[newval], %[fault]\n" \ 58 " jx %[oldval]\n" \ 59 " .previous\n" \ 60 " .section __ex_table,\"a\"\n" \ 61 " .long 1b, 5b, 2b, 5b\n" \ 62 " .previous\n" \ 63 : [oldval] "=&r" (old), [newval] "=&r" (ret), \ 64 [mem] "+m" (*(uaddr)) \ 65 : [oparg] "r" (arg), [fault] "I" (-EFAULT) \ 66 : "memory") 67 #endif 68 69 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, 70 u32 __user *uaddr) 71 { 72 #if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE 73 int oldval = 0, ret; 74 75 if (!access_ok(uaddr, sizeof(u32))) 76 return -EFAULT; 77 78 switch (op) { 79 case FUTEX_OP_SET: 80 __futex_atomic_op("mov %[newval], %[oparg]", 81 ret, oldval, uaddr, oparg); 82 break; 83 case FUTEX_OP_ADD: 84 __futex_atomic_op("add %[newval], %[oldval], %[oparg]", 85 ret, oldval, uaddr, oparg); 86 break; 87 case FUTEX_OP_OR: 88 __futex_atomic_op("or %[newval], %[oldval], %[oparg]", 89 ret, oldval, uaddr, oparg); 90 break; 91 case FUTEX_OP_ANDN: 92 __futex_atomic_op("and %[newval], %[oldval], %[oparg]", 93 ret, oldval, uaddr, ~oparg); 94 break; 95 case FUTEX_OP_XOR: 96 __futex_atomic_op("xor %[newval], %[oldval], %[oparg]", 97 ret, oldval, uaddr, oparg); 98 break; 99 default: 100 ret = -ENOSYS; 101 } 102 103 if (!ret) 104 *oval = oldval; 105 106 return ret; 107 #else 108 return -ENOSYS; 109 #endif 110 } 111 112 static inline int 113 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 114 u32 oldval, u32 newval) 115 { 116 #if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE 117 unsigned long tmp; 118 int ret = 0; 119 120 if (!access_ok(uaddr, sizeof(u32))) 121 return -EFAULT; 122 123 __asm__ __volatile__ ( 124 " # futex_atomic_cmpxchg_inatomic\n" 125 #if XCHAL_HAVE_EXCLUSIVE 126 "1: l32ex %[tmp], %[addr]\n" 127 " s32i %[tmp], %[uval], 0\n" 128 " bne %[tmp], %[oldval], 2f\n" 129 " mov %[tmp], %[newval]\n" 130 "3: s32ex %[tmp], %[addr]\n" 131 " getex %[tmp]\n" 132 " beqz %[tmp], 1b\n" 133 #elif XCHAL_HAVE_S32C1I 134 " wsr %[oldval], scompare1\n" 135 "1: s32c1i %[newval], %[addr], 0\n" 136 " s32i %[newval], %[uval], 0\n" 137 #endif 138 "2:\n" 139 " .section .fixup,\"ax\"\n" 140 " .align 4\n" 141 " .literal_position\n" 142 "4: movi %[tmp], 2b\n" 143 " movi %[ret], %[fault]\n" 144 " jx %[tmp]\n" 145 " .previous\n" 146 " .section __ex_table,\"a\"\n" 147 " .long 1b, 4b\n" 148 #if XCHAL_HAVE_EXCLUSIVE 149 " .long 3b, 4b\n" 150 #endif 151 " .previous\n" 152 : [ret] "+r" (ret), [newval] "+r" (newval), [tmp] "=&r" (tmp) 153 : [addr] "r" (uaddr), [oldval] "r" (oldval), [uval] "r" (uval), 154 [fault] "I" (-EFAULT) 155 : "memory"); 156 157 return ret; 158 #else 159 return -ENOSYS; 160 #endif 161 } 162 163 #endif /* _ASM_XTENSA_FUTEX_H */ 164