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 #define arch_futex_atomic_op_inuser arch_futex_atomic_op_inuser 20 #define futex_atomic_cmpxchg_inatomic futex_atomic_cmpxchg_inatomic 21 #include <asm-generic/futex.h> 22 23 #if XCHAL_HAVE_EXCLUSIVE 24 #define __futex_atomic_op(insn, ret, old, uaddr, arg) \ 25 __asm__ __volatile( \ 26 "1: l32ex %[oldval], %[addr]\n" \ 27 insn "\n" \ 28 "2: s32ex %[newval], %[addr]\n" \ 29 " getex %[newval]\n" \ 30 " beqz %[newval], 1b\n" \ 31 " movi %[newval], 0\n" \ 32 "3:\n" \ 33 " .section .fixup,\"ax\"\n" \ 34 " .align 4\n" \ 35 " .literal_position\n" \ 36 "5: movi %[oldval], 3b\n" \ 37 " movi %[newval], %[fault]\n" \ 38 " jx %[oldval]\n" \ 39 " .previous\n" \ 40 " .section __ex_table,\"a\"\n" \ 41 " .long 1b, 5b, 2b, 5b\n" \ 42 " .previous\n" \ 43 : [oldval] "=&r" (old), [newval] "=&r" (ret) \ 44 : [addr] "r" (uaddr), [oparg] "r" (arg), \ 45 [fault] "I" (-EFAULT) \ 46 : "memory") 47 #elif XCHAL_HAVE_S32C1I 48 #define __futex_atomic_op(insn, ret, old, uaddr, arg) \ 49 __asm__ __volatile( \ 50 "1: l32i %[oldval], %[mem]\n" \ 51 insn "\n" \ 52 " wsr %[oldval], scompare1\n" \ 53 "2: s32c1i %[newval], %[mem]\n" \ 54 " bne %[newval], %[oldval], 1b\n" \ 55 " movi %[newval], 0\n" \ 56 "3:\n" \ 57 " .section .fixup,\"ax\"\n" \ 58 " .align 4\n" \ 59 " .literal_position\n" \ 60 "5: movi %[oldval], 3b\n" \ 61 " movi %[newval], %[fault]\n" \ 62 " jx %[oldval]\n" \ 63 " .previous\n" \ 64 " .section __ex_table,\"a\"\n" \ 65 " .long 1b, 5b, 2b, 5b\n" \ 66 " .previous\n" \ 67 : [oldval] "=&r" (old), [newval] "=&r" (ret), \ 68 [mem] "+m" (*(uaddr)) \ 69 : [oparg] "r" (arg), [fault] "I" (-EFAULT) \ 70 : "memory") 71 #endif 72 73 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, 74 u32 __user *uaddr) 75 { 76 #if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE 77 int oldval = 0, ret; 78 79 if (!access_ok(uaddr, sizeof(u32))) 80 return -EFAULT; 81 82 switch (op) { 83 case FUTEX_OP_SET: 84 __futex_atomic_op("mov %[newval], %[oparg]", 85 ret, oldval, uaddr, oparg); 86 break; 87 case FUTEX_OP_ADD: 88 __futex_atomic_op("add %[newval], %[oldval], %[oparg]", 89 ret, oldval, uaddr, oparg); 90 break; 91 case FUTEX_OP_OR: 92 __futex_atomic_op("or %[newval], %[oldval], %[oparg]", 93 ret, oldval, uaddr, oparg); 94 break; 95 case FUTEX_OP_ANDN: 96 __futex_atomic_op("and %[newval], %[oldval], %[oparg]", 97 ret, oldval, uaddr, ~oparg); 98 break; 99 case FUTEX_OP_XOR: 100 __futex_atomic_op("xor %[newval], %[oldval], %[oparg]", 101 ret, oldval, uaddr, oparg); 102 break; 103 default: 104 ret = -ENOSYS; 105 } 106 107 if (!ret) 108 *oval = oldval; 109 110 return ret; 111 #else 112 return futex_atomic_op_inuser_local(op, oparg, oval, uaddr); 113 #endif 114 } 115 116 static inline int 117 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 118 u32 oldval, u32 newval) 119 { 120 #if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE 121 unsigned long tmp; 122 int ret = 0; 123 124 if (!access_ok(uaddr, sizeof(u32))) 125 return -EFAULT; 126 127 __asm__ __volatile__ ( 128 " # futex_atomic_cmpxchg_inatomic\n" 129 #if XCHAL_HAVE_EXCLUSIVE 130 "1: l32ex %[tmp], %[addr]\n" 131 " s32i %[tmp], %[uval], 0\n" 132 " bne %[tmp], %[oldval], 2f\n" 133 " mov %[tmp], %[newval]\n" 134 "3: s32ex %[tmp], %[addr]\n" 135 " getex %[tmp]\n" 136 " beqz %[tmp], 1b\n" 137 #elif XCHAL_HAVE_S32C1I 138 " wsr %[oldval], scompare1\n" 139 "1: s32c1i %[newval], %[addr], 0\n" 140 " s32i %[newval], %[uval], 0\n" 141 #endif 142 "2:\n" 143 " .section .fixup,\"ax\"\n" 144 " .align 4\n" 145 " .literal_position\n" 146 "4: movi %[tmp], 2b\n" 147 " movi %[ret], %[fault]\n" 148 " jx %[tmp]\n" 149 " .previous\n" 150 " .section __ex_table,\"a\"\n" 151 " .long 1b, 4b\n" 152 #if XCHAL_HAVE_EXCLUSIVE 153 " .long 3b, 4b\n" 154 #endif 155 " .previous\n" 156 : [ret] "+r" (ret), [newval] "+r" (newval), [tmp] "=&r" (tmp) 157 : [addr] "r" (uaddr), [oldval] "r" (oldval), [uval] "r" (uval), 158 [fault] "I" (-EFAULT) 159 : "memory"); 160 161 return ret; 162 #else 163 return futex_atomic_cmpxchg_inatomic_local(uval, uaddr, oldval, newval); 164 #endif 165 } 166 167 #endif /* _ASM_XTENSA_FUTEX_H */ 168