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1919 jermar 1
/*
2071 jermar 2
 * Copyright (c) 2006 Jakub Jermar
1919 jermar 3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1920 jermar 29
/** @addtogroup genericddi
1919 jermar 30
 * @{
31
 */
32
/**
33
 * @file
1922 jermar 34
 * @brief   IRQ dispatcher.
1919 jermar 35
 *
36
 * This file provides means of connecting IRQs with particular
37
 * devices and logic for dispatching interrupts to IRQ handlers
38
 * defined by those devices.
39
 *
40
 * This code is designed to support:
41
 * - multiple devices sharing single IRQ
42
 * - multiple IRQs per signle device
43
 *
44
 *
45
 * Note about architectures.
46
 *
47
 * Some architectures has the term IRQ well defined. Examples
48
 * of such architectures include amd64, ia32 and mips32. Some
49
 * other architectures, such as sparc64, don't use the term
50
 * at all. In those cases, we boldly step forward and define what
51
 * an IRQ is.
52
 *
53
 * The implementation is generic enough and still allows the
54
 * architectures to use the hardware layout effectively.
55
 * For instance, on amd64 and ia32, where there is only 16
56
 * IRQs, the irq_hash_table can be optimized to a one-dimensional
57
 * array. Next, when it is known that the IRQ numbers (aka INR's)
58
 * are unique, the claim functions can always return IRQ_ACCEPT.
1922 jermar 59
 *
60
 *
61
 * Note about the irq_hash_table.
62
 *
63
 * The hash table is configured to use two keys: inr and devno.
64
 * However, the hash index is computed only from inr. Moreover,
65
 * if devno is -1, the match is based on the return value of
66
 * the claim() function instead of on devno.
1919 jermar 67
 */
68
 
1920 jermar 69
#include <ddi/irq.h>
1919 jermar 70
#include <adt/hash_table.h>
71
#include <arch/types.h>
72
#include <synch/spinlock.h>
73
#include <arch.h>
74
 
1922 jermar 75
#define KEY_INR     0
76
#define KEY_DEVNO   1
77
 
1919 jermar 78
/**
79
 * Spinlock protecting the hash table.
80
 * This lock must be taken only when interrupts are disabled.
81
 */
82
SPINLOCK_INITIALIZE(irq_hash_table_lock);
83
static hash_table_t irq_hash_table;
84
 
85
/**
86
 * Hash table operations for cases when we know that
87
 * there will be collisions between different keys.
88
 */
89
static index_t irq_ht_hash(unative_t *key);
90
static bool irq_ht_compare(unative_t *key, count_t keys, link_t *item);
91
 
92
static hash_table_operations_t irq_ht_ops = {
93
    .hash = irq_ht_hash,
94
    .compare = irq_ht_compare,
95
    .remove_callback = NULL     /* not used */
96
};
97
 
98
/**
99
 * Hash table operations for cases when we know that
100
 * there will be no collisions between different keys.
101
 * However, there might be still collisions among
102
 * elements with single key (sharing of one IRQ).
103
 */
104
static index_t irq_lin_hash(unative_t *key);
105
static bool irq_lin_compare(unative_t *key, count_t keys, link_t *item);
106
 
107
static hash_table_operations_t irq_lin_ops = {
108
    .hash = irq_lin_hash,
109
    .compare = irq_lin_compare,
110
    .remove_callback = NULL     /* not used */
111
};
112
 
113
/** Initialize IRQ subsystem.
114
 *
115
 * @param inrs Numbers of unique IRQ numbers or INRs.
116
 * @param chains Number of chains in the hash table.
117
 */
118
void irq_init(count_t inrs, count_t chains)
119
{
120
    /*
121
     * Be smart about the choice of the hash table operations.
122
     * In cases in which inrs equals the requested number of
123
     * chains (i.e. where there is no collision between
124
     * different keys), we can use optimized set of operations.
125
     */
126
    if (inrs == chains)
1922 jermar 127
        hash_table_create(&irq_hash_table, chains, 2, &irq_lin_ops);
1919 jermar 128
    else
1922 jermar 129
        hash_table_create(&irq_hash_table, chains, 2, &irq_ht_ops);
1919 jermar 130
}
131
 
132
/** Initialize one IRQ structure.
133
 *
134
 * @param irq Pointer to the IRQ structure to be initialized.
135
 *
136
 */
137
void irq_initialize(irq_t *irq)
138
{
139
    link_initialize(&irq->link);
1921 jermar 140
    spinlock_initialize(&irq->lock, "irq.lock");
2218 decky 141
    irq->preack = false;
1919 jermar 142
    irq->inr = -1;
143
    irq->devno = -1;
2117 decky 144
    irq->trigger = (irq_trigger_t) 0;
1919 jermar 145
    irq->claim = NULL;
146
    irq->handler = NULL;
147
    irq->arg = NULL;
3675 svoboda 148
    irq->cir = NULL;
149
    irq->cir_arg = NULL;
1933 jermar 150
    irq->notif_cfg.notify = false;
1923 jermar 151
    irq->notif_cfg.answerbox = NULL;
152
    irq->notif_cfg.code = NULL;
153
    irq->notif_cfg.method = 0;
154
    irq->notif_cfg.counter = 0;
1933 jermar 155
    link_initialize(&irq->notif_cfg.link);
1919 jermar 156
}
157
 
158
/** Register IRQ for device.
159
 *
160
 * The irq structure must be filled with information
161
 * about the interrupt source and with the claim()
162
 * function pointer and irq_handler() function pointer.
163
 *
164
 * @param irq IRQ structure belonging to a device.
165
 */
166
void irq_register(irq_t *irq)
167
{
168
    ipl_t ipl;
1922 jermar 169
    unative_t key[] = {
170
        (unative_t) irq->inr,
171
        (unative_t) irq->devno
172
    };
1919 jermar 173
 
174
    ipl = interrupts_disable();
175
    spinlock_lock(&irq_hash_table_lock);
1922 jermar 176
    hash_table_insert(&irq_hash_table, key, &irq->link);
1919 jermar 177
    spinlock_unlock(&irq_hash_table_lock);
178
    interrupts_restore(ipl);
179
}
180
 
181
/** Dispatch the IRQ.
182
 *
1922 jermar 183
 * We assume this function is only called from interrupt
184
 * context (i.e. that interrupts are disabled prior to
185
 * this call).
186
 *
187
 * This function attempts to lookup a fitting IRQ
188
 * structure. In case of success, return with interrupts
189
 * disabled and holding the respective structure.
190
 *
1919 jermar 191
 * @param inr Interrupt number (aka inr or irq).
192
 *
193
 * @return IRQ structure of the respective device or NULL.
194
 */
1922 jermar 195
irq_t *irq_dispatch_and_lock(inr_t inr)
1919 jermar 196
{
197
    link_t *lnk;
1922 jermar 198
    unative_t key[] = {
199
        (unative_t) inr,
200
        (unative_t) -1      /* search will use claim() instead of devno */
201
    };
1919 jermar 202
 
203
    spinlock_lock(&irq_hash_table_lock);
204
 
1922 jermar 205
    lnk = hash_table_find(&irq_hash_table, key);
1919 jermar 206
    if (lnk) {
207
        irq_t *irq;
208
 
209
        irq = hash_table_get_instance(lnk, irq_t, link);
210
 
211
        spinlock_unlock(&irq_hash_table_lock);
212
        return irq;
213
    }
214
 
215
    spinlock_unlock(&irq_hash_table_lock);
216
 
217
    return NULL;   
218
}
219
 
1922 jermar 220
/** Find the IRQ structure corresponding to inr and devno.
221
 *
222
 * This functions attempts to lookup the IRQ structure
223
 * corresponding to its arguments. On success, this
224
 * function returns with interrups disabled, holding
225
 * the lock of the respective IRQ structure.
226
 *
227
 * This function assumes interrupts are already disabled.
228
 *
229
 * @param inr INR being looked up.
230
 * @param devno Devno being looked up.
231
 *
232
 * @return Locked IRQ structure on success or NULL on failure.
233
 */
234
irq_t *irq_find_and_lock(inr_t inr, devno_t devno)
235
{
236
    link_t *lnk;
237
    unative_t keys[] = {
238
        (unative_t) inr,
239
        (unative_t) devno
240
    };
241
 
242
    spinlock_lock(&irq_hash_table_lock);
243
 
244
    lnk = hash_table_find(&irq_hash_table, keys);
245
    if (lnk) {
246
        irq_t *irq;
247
 
248
        irq = hash_table_get_instance(lnk, irq_t, link);
249
 
250
        spinlock_unlock(&irq_hash_table_lock);
251
        return irq;
252
    }
253
 
254
    spinlock_unlock(&irq_hash_table_lock);
255
 
256
    return NULL;   
257
}
258
 
1919 jermar 259
/** Compute hash index for the key.
260
 *
261
 * This function computes hash index into
262
 * the IRQ hash table for which there
263
 * can be collisions between different
264
 * INRs.
265
 *
1922 jermar 266
 * The devno is not used to compute the hash.
1919 jermar 267
 *
1922 jermar 268
 * @param key The first of the keys is inr and the second is devno or -1.
269
 *
1919 jermar 270
 * @return Index into the hash table.
271
 */
1922 jermar 272
index_t irq_ht_hash(unative_t key[])
1919 jermar 273
{
1922 jermar 274
    inr_t inr = (inr_t) key[KEY_INR];
275
    return inr % irq_hash_table.entries;
1919 jermar 276
}
277
 
278
/** Compare hash table element with a key.
279
 *
1922 jermar 280
 * There are two things to note about this function.
281
 * First, it is used for the more complex architecture setup
282
 * in which there are way too many interrupt numbers (i.e. inr's)
283
 * to arrange the hash table so that collisions occur only
284
 * among same inrs of different devnos. So the explicit check
285
 * for inr match must be done.
286
 * Second, if devno is -1, the second key (i.e. devno) is not
287
 * used for the match and the result of the claim() function
288
 * is used instead.
1919 jermar 289
 *
1922 jermar 290
 * This function assumes interrupts are already disabled.
291
 *
292
 * @param key Keys (i.e. inr and devno).
293
 * @param keys This is 2.
1919 jermar 294
 * @param item The item to compare the key with.
295
 *
296
 * @return True on match or false otherwise.
297
 */
1922 jermar 298
bool irq_ht_compare(unative_t key[], count_t keys, link_t *item)
1919 jermar 299
{
300
    irq_t *irq = hash_table_get_instance(item, irq_t, link);
1922 jermar 301
    inr_t inr = (inr_t) key[KEY_INR];
302
    devno_t devno = (devno_t) key[KEY_DEVNO];
303
 
1921 jermar 304
    bool rv;
1919 jermar 305
 
1921 jermar 306
    spinlock_lock(&irq->lock);
1922 jermar 307
    if (devno == -1) {
2107 jermar 308
        /* Invoked by irq_dispatch_and_lock(). */
1922 jermar 309
        rv = ((irq->inr == inr) && (irq->claim() == IRQ_ACCEPT));
310
    } else {
2107 jermar 311
        /* Invoked by irq_find_and_lock(). */
1922 jermar 312
        rv = ((irq->inr == inr) && (irq->devno == devno));
313
    }
314
 
315
    /* unlock only on non-match */
316
    if (!rv)
317
        spinlock_unlock(&irq->lock);
1921 jermar 318
 
319
    return rv;
1919 jermar 320
}
321
 
322
/** Compute hash index for the key.
323
 *
324
 * This function computes hash index into
325
 * the IRQ hash table for which there
326
 * are no collisions between different
327
 * INRs.
328
 *
1922 jermar 329
 * @param key The first of the keys is inr and the second is devno or -1.
1919 jermar 330
 *
331
 * @return Index into the hash table.
332
 */
1922 jermar 333
index_t irq_lin_hash(unative_t key[])
1919 jermar 334
{
1922 jermar 335
    inr_t inr = (inr_t) key[KEY_INR];
336
    return inr;
1919 jermar 337
}
338
 
339
/** Compare hash table element with a key.
340
 *
1922 jermar 341
 * There are two things to note about this function.
342
 * First, it is used for the less complex architecture setup
343
 * in which there are not too many interrupt numbers (i.e. inr's)
344
 * to arrange the hash table so that collisions occur only
345
 * among same inrs of different devnos. So the explicit check
346
 * for inr match is not done.
347
 * Second, if devno is -1, the second key (i.e. devno) is not
348
 * used for the match and the result of the claim() function
349
 * is used instead.
1919 jermar 350
 *
1922 jermar 351
 * This function assumes interrupts are already disabled.
352
 *
353
 * @param key Keys (i.e. inr and devno).
354
 * @param keys This is 2.
1919 jermar 355
 * @param item The item to compare the key with.
356
 *
357
 * @return True on match or false otherwise.
358
 */
1922 jermar 359
bool irq_lin_compare(unative_t key[], count_t keys, link_t *item)
1919 jermar 360
{
361
    irq_t *irq = list_get_instance(item, irq_t, link);
1922 jermar 362
    devno_t devno = (devno_t) key[KEY_DEVNO];
1921 jermar 363
    bool rv;
1919 jermar 364
 
1921 jermar 365
    spinlock_lock(&irq->lock);
1922 jermar 366
    if (devno == -1) {
2107 jermar 367
        /* Invoked by irq_dispatch_and_lock() */
1922 jermar 368
        rv = (irq->claim() == IRQ_ACCEPT);
369
    } else {
2107 jermar 370
        /* Invoked by irq_find_and_lock() */
1922 jermar 371
        rv = (irq->devno == devno);
372
    }
1921 jermar 373
 
1922 jermar 374
    /* unlock only on non-match */
375
    if (!rv)
376
        spinlock_unlock(&irq->lock);
377
 
1921 jermar 378
    return rv;
1919 jermar 379
}
380
 
381
/** @}
382
 */