1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "apr_arch_atomic.h"
18
19#ifdef USE_ATOMICS_PPC
20
21#ifdef PPC405_ERRATA
22#   define PPC405_ERR77_SYNC   "    sync\n"
23#else
24#   define PPC405_ERR77_SYNC
25#endif
26
27APR_DECLARE(apr_status_t) apr_atomic_init(apr_pool_t *p)
28{
29#if defined (NEED_ATOMICS_GENERIC64)
30    return apr__atomic_generic64_init(p);
31#else
32    return APR_SUCCESS;
33#endif
34}
35
36APR_DECLARE(apr_uint32_t) apr_atomic_read32(volatile apr_uint32_t *mem)
37{
38    return *mem;
39}
40
41APR_DECLARE(void) apr_atomic_set32(volatile apr_uint32_t *mem, apr_uint32_t val)
42{
43    *mem = val;
44}
45
46APR_DECLARE(apr_uint32_t) apr_atomic_add32(volatile apr_uint32_t *mem, apr_uint32_t val)
47{
48    apr_uint32_t prev, temp;
49
50    asm volatile ("1:\n"                       /* lost reservation     */
51                  "    lwarx   %0,0,%3\n"      /* load and reserve     */
52                  "    add     %1,%0,%4\n"     /* add val and prev     */
53                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
54                  "    stwcx.  %1,0,%3\n"      /* store new value      */
55                  "    bne-    1b\n"           /* loop if lost         */
56                  : "=&r" (prev), "=&r" (temp), "=m" (*mem)
57                  : "b" (mem), "r" (val)
58                  : "cc", "memory");
59
60    return prev;
61}
62
63APR_DECLARE(void) apr_atomic_sub32(volatile apr_uint32_t *mem, apr_uint32_t val)
64{
65    apr_uint32_t temp;
66
67    asm volatile ("1:\n"                       /* lost reservation     */
68                  "    lwarx   %0,0,%2\n"      /* load and reserve     */
69                  "    subf    %0,%3,%0\n"     /* subtract val         */
70                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
71                  "    stwcx.  %0,0,%2\n"      /* store new value      */
72                  "    bne-    1b\n"           /* loop if lost         */
73                  : "=&r" (temp), "=m" (*mem)
74                  : "b" (mem), "r" (val)
75                  : "cc", "memory");
76}
77
78APR_DECLARE(apr_uint32_t) apr_atomic_inc32(volatile apr_uint32_t *mem)
79{
80    apr_uint32_t prev;
81
82    asm volatile ("1:\n"                       /* lost reservation     */
83                  "    lwarx   %0,0,%2\n"      /* load and reserve     */
84                  "    addi    %0,%0,1\n"      /* add immediate        */
85                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
86                  "    stwcx.  %0,0,%2\n"      /* store new value      */
87                  "    bne-    1b\n"           /* loop if lost         */
88                  "    subi    %0,%0,1\n"      /* return old value     */
89                  : "=&b" (prev), "=m" (*mem)
90                  : "b" (mem), "m" (*mem)
91                  : "cc", "memory");
92
93    return prev;
94}
95
96APR_DECLARE(int) apr_atomic_dec32(volatile apr_uint32_t *mem)
97{
98    apr_uint32_t prev;
99
100    asm volatile ("1:\n"                       /* lost reservation     */
101                  "    lwarx   %0,0,%2\n"      /* load and reserve     */
102                  "    subi    %0,%0,1\n"      /* subtract immediate   */
103                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
104                  "    stwcx.  %0,0,%2\n"      /* store new value      */
105                  "    bne-    1b\n"           /* loop if lost         */
106                  : "=&b" (prev), "=m" (*mem)
107                  : "b" (mem), "m" (*mem)
108                  : "cc", "memory");
109
110    return prev;
111}
112
113APR_DECLARE(apr_uint32_t) apr_atomic_cas32(volatile apr_uint32_t *mem, apr_uint32_t with,
114                                           apr_uint32_t cmp)
115{
116    apr_uint32_t prev;
117
118    asm volatile ("1:\n"                       /* lost reservation     */
119                  "    lwarx   %0,0,%1\n"      /* load and reserve     */
120                  "    cmpw    %0,%3\n"        /* compare operands     */
121                  "    bne-    exit_%=\n"      /* skip if not equal    */
122                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
123                  "    stwcx.  %2,0,%1\n"      /* store new value      */
124                  "    bne-    1b\n"           /* loop if lost         */
125                  "exit_%=:\n"                 /* not equal            */
126                  : "=&r" (prev)
127                  : "b" (mem), "r" (with), "r" (cmp)
128                  : "cc", "memory");
129
130    return prev;
131}
132
133APR_DECLARE(apr_uint32_t) apr_atomic_xchg32(volatile apr_uint32_t *mem, apr_uint32_t val)
134{
135    apr_uint32_t prev;
136
137    asm volatile ("1:\n"                       /* lost reservation     */
138                  "    lwarx   %0,0,%1\n"      /* load and reserve     */
139                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
140                  "    stwcx.  %2,0,%1\n"      /* store new value      */
141                  "    bne-    1b"             /* loop if lost         */
142                  : "=&r" (prev)
143                  : "b" (mem), "r" (val)
144                  : "cc", "memory");
145
146    return prev;
147}
148
149APR_DECLARE(void*) apr_atomic_casptr(volatile void **mem, void *with, const void *cmp)
150{
151    void *prev;
152#if APR_SIZEOF_VOIDP == 4
153    asm volatile ("1:\n"                       /* lost reservation     */
154                  "    lwarx   %0,0,%1\n"      /* load and reserve     */
155                  "    cmpw    %0,%3\n"        /* compare operands     */
156                  "    bne-    2f\n"           /* skip if not equal    */
157                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
158                  "    stwcx.  %2,0,%1\n"      /* store new value      */
159                  "    bne-    1b\n"           /* loop if lost         */
160                  "2:\n"                       /* not equal            */
161                  : "=&r" (prev)
162                  : "b" (mem), "r" (with), "r" (cmp)
163                  : "cc", "memory");
164#elif APR_SIZEOF_VOIDP == 8
165    asm volatile ("1:\n"                       /* lost reservation     */
166                  "    ldarx   %0,0,%1\n"      /* load and reserve     */
167                  "    cmpd    %0,%3\n"        /* compare operands     */
168                  "    bne-    2f\n"           /* skip if not equal    */
169                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
170                  "    stdcx.  %2,0,%1\n"      /* store new value      */
171                  "    bne-    1b\n"           /* loop if lost         */
172                  "2:\n"                       /* not equal            */
173                  : "=&r" (prev)
174                  : "b" (mem), "r" (with), "r" (cmp)
175                  : "cc", "memory");
176#else
177#error APR_SIZEOF_VOIDP value not supported
178#endif
179    return prev;
180}
181
182APR_DECLARE(void*) apr_atomic_xchgptr(volatile void **mem, void *with)
183{
184    void *prev;
185#if APR_SIZEOF_VOIDP == 4
186    asm volatile ("1:\n"                       /* lost reservation     */
187                  "    lwarx   %0,0,%1\n"      /* load and reserve     */
188                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
189                  "    stwcx.  %2,0,%1\n"      /* store new value      */
190                  "    bne-    1b\n"           /* loop if lost         */
191                  "    isync\n"                /* memory barrier       */
192                  : "=&r" (prev)
193                  : "b" (mem), "r" (with)
194                  : "cc", "memory");
195#elif APR_SIZEOF_VOIDP == 8
196    asm volatile ("1:\n"                       /* lost reservation     */
197                  "    ldarx   %0,0,%1\n"      /* load and reserve     */
198                  PPC405_ERR77_SYNC            /* ppc405 Erratum 77    */
199                  "    stdcx.  %2,0,%1\n"      /* store new value      */
200                  "    bne-    1b\n"           /* loop if lost         */
201                  "    isync\n"                /* memory barrier       */
202                  : "=&r" (prev)
203                  : "b" (mem), "r" (with)
204                  : "cc", "memory");
205#else
206#error APR_SIZEOF_VOIDP value not supported
207#endif
208    return prev;
209}
210
211#endif /* USE_ATOMICS_PPC */
212