1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org) 7 */ 8 #ifndef _ASM_FUTEX_H 9 #define _ASM_FUTEX_H 10 11 #ifdef __KERNEL__ 12 13 #include <linux/futex.h> 14 #include <linux/uaccess.h> 15 #include <asm/asm-eva.h> 16 #include <asm/barrier.h> 17 #include <asm/compiler.h> 18 #include <asm/errno.h> 19 #include <asm/war.h> 20 21 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ 22 { \ 23 if (cpu_has_llsc && R10000_LLSC_WAR) { \ 24 __asm__ __volatile__( \ 25 " .set push \n" \ 26 " .set noat \n" \ 27 " .set arch=r4000 \n" \ 28 "1: ll %1, %4 # __futex_atomic_op \n" \ 29 " .set mips0 \n" \ 30 " " insn " \n" \ 31 " .set arch=r4000 \n" \ 32 "2: sc $1, %2 \n" \ 33 " beqzl $1, 1b \n" \ 34 __WEAK_LLSC_MB \ 35 "3: \n" \ 36 " .insn \n" \ 37 " .set pop \n" \ 38 " .set mips0 \n" \ 39 " .section .fixup,\"ax\" \n" \ 40 "4: li %0, %6 \n" \ 41 " j 3b \n" \ 42 " .previous \n" \ 43 " .section __ex_table,\"a\" \n" \ 44 " "__UA_ADDR "\t1b, 4b \n" \ 45 " "__UA_ADDR "\t2b, 4b \n" \ 46 " .previous \n" \ 47 : "=r" (ret), "=&r" (oldval), \ 48 "=" GCC_OFF_SMALL_ASM() (*uaddr) \ 49 : "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg), \ 50 "i" (-EFAULT) \ 51 : "memory"); \ 52 } else if (cpu_has_llsc) { \ 53 __asm__ __volatile__( \ 54 " .set push \n" \ 55 " .set noat \n" \ 56 " .set "MIPS_ISA_ARCH_LEVEL" \n" \ 57 "1: "user_ll("%1", "%4")" # __futex_atomic_op\n" \ 58 " .set mips0 \n" \ 59 " " insn " \n" \ 60 " .set "MIPS_ISA_ARCH_LEVEL" \n" \ 61 "2: "user_sc("$1", "%2")" \n" \ 62 " beqz $1, 1b \n" \ 63 __WEAK_LLSC_MB \ 64 "3: \n" \ 65 " .insn \n" \ 66 " .set pop \n" \ 67 " .set mips0 \n" \ 68 " .section .fixup,\"ax\" \n" \ 69 "4: li %0, %6 \n" \ 70 " j 3b \n" \ 71 " .previous \n" \ 72 " .section __ex_table,\"a\" \n" \ 73 " "__UA_ADDR "\t1b, 4b \n" \ 74 " "__UA_ADDR "\t2b, 4b \n" \ 75 " .previous \n" \ 76 : "=r" (ret), "=&r" (oldval), \ 77 "=" GCC_OFF_SMALL_ASM() (*uaddr) \ 78 : "0" (0), GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oparg), \ 79 "i" (-EFAULT) \ 80 : "memory"); \ 81 } else \ 82 ret = -ENOSYS; \ 83 } 84 85 static inline int 86 futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr) 87 { 88 int op = (encoded_op >> 28) & 7; 89 int cmp = (encoded_op >> 24) & 15; 90 int oparg = (encoded_op << 8) >> 20; 91 int cmparg = (encoded_op << 20) >> 20; 92 int oldval = 0, ret; 93 if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) 94 oparg = 1 << oparg; 95 96 if (! access_ok (VERIFY_WRITE, uaddr, sizeof(u32))) 97 return -EFAULT; 98 99 pagefault_disable(); 100 101 switch (op) { 102 case FUTEX_OP_SET: 103 __futex_atomic_op("move $1, %z5", ret, oldval, uaddr, oparg); 104 break; 105 106 case FUTEX_OP_ADD: 107 __futex_atomic_op("addu $1, %1, %z5", 108 ret, oldval, uaddr, oparg); 109 break; 110 case FUTEX_OP_OR: 111 __futex_atomic_op("or $1, %1, %z5", 112 ret, oldval, uaddr, oparg); 113 break; 114 case FUTEX_OP_ANDN: 115 __futex_atomic_op("and $1, %1, %z5", 116 ret, oldval, uaddr, ~oparg); 117 break; 118 case FUTEX_OP_XOR: 119 __futex_atomic_op("xor $1, %1, %z5", 120 ret, oldval, uaddr, oparg); 121 break; 122 default: 123 ret = -ENOSYS; 124 } 125 126 pagefault_enable(); 127 128 if (!ret) { 129 switch (cmp) { 130 case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break; 131 case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break; 132 case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break; 133 case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break; 134 case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break; 135 case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break; 136 default: ret = -ENOSYS; 137 } 138 } 139 return ret; 140 } 141 142 static inline int 143 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, 144 u32 oldval, u32 newval) 145 { 146 int ret = 0; 147 u32 val; 148 149 if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))) 150 return -EFAULT; 151 152 if (cpu_has_llsc && R10000_LLSC_WAR) { 153 __asm__ __volatile__( 154 "# futex_atomic_cmpxchg_inatomic \n" 155 " .set push \n" 156 " .set noat \n" 157 " .set arch=r4000 \n" 158 "1: ll %1, %3 \n" 159 " bne %1, %z4, 3f \n" 160 " .set mips0 \n" 161 " move $1, %z5 \n" 162 " .set arch=r4000 \n" 163 "2: sc $1, %2 \n" 164 " beqzl $1, 1b \n" 165 __WEAK_LLSC_MB 166 "3: \n" 167 " .insn \n" 168 " .set pop \n" 169 " .section .fixup,\"ax\" \n" 170 "4: li %0, %6 \n" 171 " j 3b \n" 172 " .previous \n" 173 " .section __ex_table,\"a\" \n" 174 " "__UA_ADDR "\t1b, 4b \n" 175 " "__UA_ADDR "\t2b, 4b \n" 176 " .previous \n" 177 : "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr) 178 : GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval), 179 "i" (-EFAULT) 180 : "memory"); 181 } else if (cpu_has_llsc) { 182 __asm__ __volatile__( 183 "# futex_atomic_cmpxchg_inatomic \n" 184 " .set push \n" 185 " .set noat \n" 186 " .set "MIPS_ISA_ARCH_LEVEL" \n" 187 "1: "user_ll("%1", "%3")" \n" 188 " bne %1, %z4, 3f \n" 189 " .set mips0 \n" 190 " move $1, %z5 \n" 191 " .set "MIPS_ISA_ARCH_LEVEL" \n" 192 "2: "user_sc("$1", "%2")" \n" 193 " beqz $1, 1b \n" 194 __WEAK_LLSC_MB 195 "3: \n" 196 " .insn \n" 197 " .set pop \n" 198 " .section .fixup,\"ax\" \n" 199 "4: li %0, %6 \n" 200 " j 3b \n" 201 " .previous \n" 202 " .section __ex_table,\"a\" \n" 203 " "__UA_ADDR "\t1b, 4b \n" 204 " "__UA_ADDR "\t2b, 4b \n" 205 " .previous \n" 206 : "+r" (ret), "=&r" (val), "=" GCC_OFF_SMALL_ASM() (*uaddr) 207 : GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval), 208 "i" (-EFAULT) 209 : "memory"); 210 } else 211 return -ENOSYS; 212 213 *uval = val; 214 return ret; 215 } 216 217 #endif 218 #endif /* _ASM_FUTEX_H */ 219