| 1 | #ifndef _URCU_UATOMIC_ARCH_S390_H |
| 2 | #define _URCU_UATOMIC_ARCH_S390_H |
| 3 | |
| 4 | /* |
| 5 | * Atomic exchange operations for the S390 architecture. Based on information |
| 6 | * taken from the Principles of Operation Appendix A "Conditional Swapping |
| 7 | * Instructions (CS, CDS)". |
| 8 | * |
| 9 | * Copyright (c) 2009 Novell, Inc. |
| 10 | * Author: Jan Blunck <jblunck@suse.de> |
| 11 | * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 12 | * |
| 13 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 14 | * of this software and associated documentation files (the "Software"), to |
| 15 | * deal in the Software without restriction, including without limitation the |
| 16 | * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or |
| 17 | * sell copies of the Software, and to permit persons to whom the Software is |
| 18 | * furnished to do so, subject to the following conditions: |
| 19 | * |
| 20 | * The above copyright notice and this permission notice shall be included in |
| 21 | * all copies or substantial portions of the Software. |
| 22 | * |
| 23 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 24 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 25 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 26 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 27 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 28 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 29 | * IN THE SOFTWARE. |
| 30 | */ |
| 31 | |
| 32 | #include <urcu/compiler.h> |
| 33 | #include <urcu/system.h> |
| 34 | |
| 35 | #ifdef __cplusplus |
| 36 | extern "C" { |
| 37 | #endif |
| 38 | |
| 39 | #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) |
| 40 | #define COMPILER_HAVE_SHORT_MEM_OPERAND |
| 41 | #endif |
| 42 | |
| 43 | /* |
| 44 | * MEMOP assembler operand rules: |
| 45 | * - op refer to MEMOP_IN operand |
| 46 | * - MEMOP_IN can expand to more than a single operand. Use it at the end of |
| 47 | * operand list only. |
| 48 | */ |
| 49 | |
| 50 | #ifdef COMPILER_HAVE_SHORT_MEM_OPERAND |
| 51 | |
| 52 | #define MEMOP_OUT(addr) "=Q" (*(addr)) |
| 53 | #define MEMOP_IN(addr) "Q" (*(addr)) |
| 54 | #define MEMOP_REF(op) #op /* op refer to MEMOP_IN operand */ |
| 55 | |
| 56 | #else /* !COMPILER_HAVE_SHORT_MEM_OPERAND */ |
| 57 | |
| 58 | #define MEMOP_OUT(addr) "=m" (*(addr)) |
| 59 | #define MEMOP_IN(addr) "a" (addr), "m" (*(addr)) |
| 60 | #define MEMOP_REF(op) "0(" #op ")" /* op refer to MEMOP_IN operand */ |
| 61 | |
| 62 | #endif /* !COMPILER_HAVE_SHORT_MEM_OPERAND */ |
| 63 | |
| 64 | /* |
| 65 | * The __hp() macro casts the void pointer @x to a pointer to a structure |
| 66 | * containing an array of char of the specified size. This allows passing the |
| 67 | * @addr arguments of the following inline functions as "m" and "+m" operands |
| 68 | * to the assembly. The @size parameter should be a constant to support |
| 69 | * compilers such as clang which do not support VLA. Create typedefs because |
| 70 | * C++ does not allow types be defined in casts. |
| 71 | */ |
| 72 | |
| 73 | typedef struct { char v[4]; } __hp_4; |
| 74 | typedef struct { char v[8]; } __hp_8; |
| 75 | |
| 76 | #define __hp(size, x) ((__hp_##size *)(x)) |
| 77 | |
| 78 | /* xchg */ |
| 79 | |
| 80 | static inline __attribute__((always_inline)) |
| 81 | unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len) |
| 82 | { |
| 83 | switch (len) { |
| 84 | case 4: |
| 85 | { |
| 86 | unsigned int old_val; |
| 87 | |
| 88 | __asm__ __volatile__( |
| 89 | "0: cs %0,%2," MEMOP_REF(%3) "\n" |
| 90 | " brc 4,0b\n" |
| 91 | : "=&r" (old_val), MEMOP_OUT (__hp(4, addr)) |
| 92 | : "r" (val), MEMOP_IN (__hp(4, addr)) |
| 93 | : "memory", "cc"); |
| 94 | return old_val; |
| 95 | } |
| 96 | #if (CAA_BITS_PER_LONG == 64) |
| 97 | case 8: |
| 98 | { |
| 99 | unsigned long old_val; |
| 100 | |
| 101 | __asm__ __volatile__( |
| 102 | "0: csg %0,%2," MEMOP_REF(%3) "\n" |
| 103 | " brc 4,0b\n" |
| 104 | : "=&r" (old_val), MEMOP_OUT (__hp(8, addr)) |
| 105 | : "r" (val), MEMOP_IN (__hp(8, addr)) |
| 106 | : "memory", "cc"); |
| 107 | return old_val; |
| 108 | } |
| 109 | #endif |
| 110 | default: |
| 111 | __asm__ __volatile__(".long 0xd00d00"); |
| 112 | } |
| 113 | |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | #define uatomic_xchg(addr, v) \ |
| 118 | (__typeof__(*(addr))) _uatomic_exchange((addr), \ |
| 119 | caa_cast_long_keep_sign(v), \ |
| 120 | sizeof(*(addr))) |
| 121 | |
| 122 | /* cmpxchg */ |
| 123 | |
| 124 | static inline __attribute__((always_inline)) |
| 125 | unsigned long _uatomic_cmpxchg(void *addr, unsigned long old, |
| 126 | unsigned long _new, int len) |
| 127 | { |
| 128 | switch (len) { |
| 129 | case 4: |
| 130 | { |
| 131 | unsigned int old_val = (unsigned int)old; |
| 132 | |
| 133 | __asm__ __volatile__( |
| 134 | " cs %0,%2," MEMOP_REF(%3) "\n" |
| 135 | : "+r" (old_val), MEMOP_OUT (__hp(4, addr)) |
| 136 | : "r" (_new), MEMOP_IN (__hp(4, addr)) |
| 137 | : "memory", "cc"); |
| 138 | return old_val; |
| 139 | } |
| 140 | #if (CAA_BITS_PER_LONG == 64) |
| 141 | case 8: |
| 142 | { |
| 143 | __asm__ __volatile__( |
| 144 | " csg %0,%2," MEMOP_REF(%3) "\n" |
| 145 | : "+r" (old), MEMOP_OUT (__hp(8, addr)) |
| 146 | : "r" (_new), MEMOP_IN (__hp(8, addr)) |
| 147 | : "memory", "cc"); |
| 148 | return old; |
| 149 | } |
| 150 | #endif |
| 151 | default: |
| 152 | __asm__ __volatile__(".long 0xd00d00"); |
| 153 | } |
| 154 | |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | #define uatomic_cmpxchg(addr, old, _new) \ |
| 159 | (__typeof__(*(addr))) _uatomic_cmpxchg((addr), \ |
| 160 | caa_cast_long_keep_sign(old), \ |
| 161 | caa_cast_long_keep_sign(_new),\ |
| 162 | sizeof(*(addr))) |
| 163 | |
| 164 | #ifdef __cplusplus |
| 165 | } |
| 166 | #endif |
| 167 | |
| 168 | #include <urcu/uatomic/generic.h> |
| 169 | |
| 170 | #endif /* _URCU_UATOMIC_ARCH_S390_H */ |