1 | /* |
---|
2 | * Description: |
---|
3 | * HPPA fast spinlock semaphores based on LDCWX instruction. |
---|
4 | * These semaphores are not known to RTEMS. |
---|
5 | * |
---|
6 | * TODO: |
---|
7 | * Put node number in high 16 bits of flag?? |
---|
8 | * XXX: Need h_s_deallocate |
---|
9 | * |
---|
10 | * COPYRIGHT (c) 1994 by Division Incorporated |
---|
11 | * |
---|
12 | * The license and distribution terms for this file may in |
---|
13 | * the file LICENSE in this distribution or at |
---|
14 | * http://www.OARcorp.com/rtems/license.html. |
---|
15 | * |
---|
16 | * $Id$ |
---|
17 | */ |
---|
18 | |
---|
19 | #include <bsp.h> |
---|
20 | |
---|
21 | #include "semaphore.h" |
---|
22 | |
---|
23 | /* |
---|
24 | * Report fatal semaphore error |
---|
25 | */ |
---|
26 | |
---|
27 | #define SEM_FATAL_ERROR(sp) rtems_fatal_error_occurred((rtems_unsigned32) sp) |
---|
28 | |
---|
29 | #define SEM_CHECK(sp) do { \ |
---|
30 | if (((sp) == 0) || (int) (sp) & 0xf) \ |
---|
31 | { \ |
---|
32 | SEM_FATAL_ERROR(sp); \ |
---|
33 | } \ |
---|
34 | } while (0) |
---|
35 | |
---|
36 | /* |
---|
37 | * Init a semaphore to be free |
---|
38 | */ |
---|
39 | |
---|
40 | #define SEM_FREE_INIT(sp) \ |
---|
41 | do { \ |
---|
42 | (sp)->lock = 1; \ |
---|
43 | (sp)->flags = 0; \ |
---|
44 | (sp)->owner_tcb = 0; \ |
---|
45 | } while (0) |
---|
46 | |
---|
47 | /* |
---|
48 | * Grab a semaphore recording its owner. |
---|
49 | */ |
---|
50 | |
---|
51 | #define SEM_MARK_GRABBED(sp) \ |
---|
52 | do { \ |
---|
53 | (sp)->owner_tcb = _Thread_Executing; \ |
---|
54 | } while (0) |
---|
55 | |
---|
56 | /* |
---|
57 | * Mark the semaphore busy |
---|
58 | */ |
---|
59 | |
---|
60 | #define SEM_MARK_BUSY(sp) ((sp)->flags |= HPPA_SEM_IN_USE) |
---|
61 | |
---|
62 | /* |
---|
63 | * Is a semaphore available? |
---|
64 | */ |
---|
65 | |
---|
66 | #define SEM_IS_AVAILABLE(sp) ((sp)->owner_tcb == 0) |
---|
67 | |
---|
68 | /* |
---|
69 | * The pool control semaphore is the first in the pool |
---|
70 | */ |
---|
71 | |
---|
72 | #define SEM_CONTROL (&hppa_semaphore_pool[0]) |
---|
73 | #define SEM_FIRST (&hppa_semaphore_pool[1]) |
---|
74 | |
---|
75 | #define SEM_PRIVATE(cookie) rtems_interrupt_disable(cookie) |
---|
76 | |
---|
77 | #define SEM_PUBLIC(cookie) rtems_interrupt_enable(cookie) |
---|
78 | |
---|
79 | |
---|
80 | /* |
---|
81 | * Control variables for the pool |
---|
82 | */ |
---|
83 | |
---|
84 | hppa_semaphore_t *hppa_semaphore_pool; /* ptr to first */ |
---|
85 | int hppa_semaphores; |
---|
86 | int hppa_semaphores_available; |
---|
87 | |
---|
88 | void |
---|
89 | hppa_semaphore_pool_initialize(void *pool_base, |
---|
90 | int pool_size) |
---|
91 | { |
---|
92 | hppa_semaphore_t *sp; |
---|
93 | int align_factor; |
---|
94 | rtems_unsigned32 isr_level; |
---|
95 | |
---|
96 | /* |
---|
97 | * round pool_base up to be a multiple of SEM_ALIGN |
---|
98 | */ |
---|
99 | |
---|
100 | align_factor = SEM_ALIGN - (((int) pool_base) & (SEM_ALIGN-1)); |
---|
101 | if (align_factor != SEM_ALIGN) |
---|
102 | { |
---|
103 | pool_base += align_factor; |
---|
104 | pool_size -= align_factor; |
---|
105 | } |
---|
106 | |
---|
107 | /* |
---|
108 | * How many can the pool hold? |
---|
109 | * Assumes the semaphores are SEM_ALIGN bytes each |
---|
110 | */ |
---|
111 | |
---|
112 | if (sizeof(hppa_semaphore_t) != SEM_ALIGN) |
---|
113 | rtems_fatal_error_occurred(RTEMS_INVALID_SIZE); |
---|
114 | |
---|
115 | pool_size &= ~(SEM_ALIGN - 1); |
---|
116 | |
---|
117 | SEM_PRIVATE(isr_level); |
---|
118 | |
---|
119 | hppa_semaphore_pool = pool_base; |
---|
120 | hppa_semaphores = pool_size / SEM_ALIGN; |
---|
121 | |
---|
122 | /* |
---|
123 | * If we are node0, then init all in the pool |
---|
124 | */ |
---|
125 | |
---|
126 | if (cpu_number == 0) |
---|
127 | { |
---|
128 | /* |
---|
129 | * Tell other cpus we are not done, jic |
---|
130 | */ |
---|
131 | SEM_CONTROL->user = rtems_build_name('!', 'D', 'N', 'E'); |
---|
132 | |
---|
133 | for (sp=SEM_FIRST; sp < &hppa_semaphore_pool[hppa_semaphores]; sp++) |
---|
134 | SEM_FREE_INIT(sp); |
---|
135 | SEM_FREE_INIT(SEM_CONTROL); |
---|
136 | } |
---|
137 | |
---|
138 | /* |
---|
139 | * Tell other cpus we are done, or wait for it to be done if on another cpu |
---|
140 | */ |
---|
141 | |
---|
142 | if (cpu_number == 0) |
---|
143 | SEM_CONTROL->user = rtems_build_name('D', 'O', 'N', 'E'); |
---|
144 | else |
---|
145 | while (SEM_CONTROL->user != rtems_build_name('D', 'O', 'N', 'E')) |
---|
146 | ; |
---|
147 | |
---|
148 | hppa_semaphores_available = hppa_semaphores; |
---|
149 | |
---|
150 | SEM_PUBLIC(isr_level); |
---|
151 | } |
---|
152 | |
---|
153 | /* |
---|
154 | * Function: hppa_semaphore_acquire |
---|
155 | * Created: 94/11/29 |
---|
156 | * RespEngr: tony bennett |
---|
157 | * |
---|
158 | * Description: |
---|
159 | * Acquire a semaphore. Will spin on the semaphore unless |
---|
160 | * 'flag' says not to. |
---|
161 | * |
---|
162 | * Parameters: |
---|
163 | * |
---|
164 | * |
---|
165 | * Returns: |
---|
166 | * 0 -- if did not acquire |
---|
167 | * non-zero -- if acquired semaphore |
---|
168 | * (actually this is the spin count) |
---|
169 | * |
---|
170 | * Notes: |
---|
171 | * There is no requirement that the semaphore be within the pool |
---|
172 | * |
---|
173 | * Deficiencies/ToDo: |
---|
174 | * |
---|
175 | */ |
---|
176 | |
---|
177 | |
---|
178 | rtems_unsigned32 |
---|
179 | hppa_semaphore_acquire(hppa_semaphore_t *sp, |
---|
180 | int flag) |
---|
181 | { |
---|
182 | rtems_unsigned32 lock_value; |
---|
183 | rtems_unsigned32 spin_count = 1; |
---|
184 | |
---|
185 | SEM_CHECK(sp); |
---|
186 | |
---|
187 | for (;;) |
---|
188 | { |
---|
189 | HPPA_ASM_LDCWS(0, 0, sp, lock_value); |
---|
190 | |
---|
191 | if (lock_value) /* we now own the lock */ |
---|
192 | { |
---|
193 | SEM_MARK_GRABBED(sp); |
---|
194 | return spin_count ? spin_count : ~0; /* jic */ |
---|
195 | } |
---|
196 | |
---|
197 | if (flag & HPPA_SEM_NO_SPIN) |
---|
198 | return 0; |
---|
199 | |
---|
200 | spin_count++; |
---|
201 | } |
---|
202 | } |
---|
203 | |
---|
204 | void |
---|
205 | hppa_semaphore_release(hppa_semaphore_t *sp) |
---|
206 | { |
---|
207 | SEM_CHECK(sp); |
---|
208 | |
---|
209 | if (sp->owner_tcb != _Thread_Executing) |
---|
210 | SEM_FATAL_ERROR("owner mismatch"); |
---|
211 | |
---|
212 | sp->lock = 1; |
---|
213 | } |
---|
214 | |
---|
215 | |
---|
216 | /* |
---|
217 | * Function: hppa_semaphore_allocate |
---|
218 | * Created: 94/11/29 |
---|
219 | * RespEngr: tony bennett |
---|
220 | * |
---|
221 | * Description: |
---|
222 | * Get a pointer to a semaphore. |
---|
223 | * |
---|
224 | * Parameters: |
---|
225 | * which -- if 0, then allocate a free semaphore from the pool |
---|
226 | * if non-zero, then return pointer to that one, even |
---|
227 | * if it is already busy. |
---|
228 | * |
---|
229 | * Returns: |
---|
230 | * successful -- pointer to semaphore |
---|
231 | * NULL otherwise |
---|
232 | * |
---|
233 | * Notes: |
---|
234 | * |
---|
235 | * |
---|
236 | * Deficiencies/ToDo: |
---|
237 | * |
---|
238 | * |
---|
239 | */ |
---|
240 | |
---|
241 | hppa_semaphore_t * |
---|
242 | hppa_semaphore_allocate(rtems_unsigned32 which, |
---|
243 | int flag) |
---|
244 | { |
---|
245 | hppa_semaphore_t *sp = 0; |
---|
246 | |
---|
247 | /* |
---|
248 | * grab the control semaphore |
---|
249 | */ |
---|
250 | |
---|
251 | if (hppa_semaphore_acquire(SEM_CONTROL, 0) == 0) |
---|
252 | SEM_FATAL_ERROR("could not grab control semaphore"); |
---|
253 | |
---|
254 | /* |
---|
255 | * Find a free one and init it |
---|
256 | */ |
---|
257 | |
---|
258 | if (which) |
---|
259 | { |
---|
260 | if (which >= hppa_semaphores) |
---|
261 | SEM_FATAL_ERROR("requested non-existent semaphore"); |
---|
262 | sp = &hppa_semaphore_pool[which]; |
---|
263 | |
---|
264 | /* |
---|
265 | * if it is "free", then mark it claimed now. |
---|
266 | * If it is not free then we are done. |
---|
267 | */ |
---|
268 | |
---|
269 | if (SEM_IS_AVAILABLE(sp)) |
---|
270 | goto allmine; |
---|
271 | } |
---|
272 | else for (sp = SEM_FIRST; |
---|
273 | sp < &hppa_semaphore_pool[hppa_semaphores]; |
---|
274 | sp++) |
---|
275 | { |
---|
276 | if (SEM_IS_AVAILABLE(sp)) |
---|
277 | { |
---|
278 | allmine: SEM_FREE_INIT(sp); |
---|
279 | SEM_MARK_BUSY(sp); |
---|
280 | if ( ! (flag & HPPA_SEM_INITIALLY_FREE)) |
---|
281 | SEM_MARK_GRABBED(sp); |
---|
282 | break; |
---|
283 | } |
---|
284 | } |
---|
285 | |
---|
286 | /* |
---|
287 | * Free up the control semaphore |
---|
288 | */ |
---|
289 | |
---|
290 | hppa_semaphore_release(SEM_CONTROL); |
---|
291 | |
---|
292 | return sp; |
---|
293 | } |
---|
294 | |
---|