xref: /openbmc/qemu/hw/intc/grlib_irqmp.c (revision 7ed9a5f626a6c932a8c869a91e6a8b3e2029f5ef)
1 /*
2  * QEMU GRLIB IRQMP Emulator
3  *
4  * (Extended interrupt not supported)
5  *
6  * SPDX-License-Identifier: MIT
7  *
8  * Copyright (c) 2010-2024 AdaCore
9  *
10  * Permission is hereby granted, free of charge, to any person obtaining a copy
11  * of this software and associated documentation files (the "Software"), to deal
12  * in the Software without restriction, including without limitation the rights
13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14  * copies of the Software, and to permit persons to whom the Software is
15  * furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice shall be included in
18  * all copies or substantial portions of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26  * THE SOFTWARE.
27  */
28 
29 #include "qemu/osdep.h"
30 #include "hw/irq.h"
31 #include "hw/sysbus.h"
32 
33 #include "hw/qdev-properties.h"
34 #include "hw/intc/grlib_irqmp.h"
35 
36 #include "trace.h"
37 #include "qapi/error.h"
38 #include "qemu/module.h"
39 #include "qom/object.h"
40 
41 #define IRQMP_MAX_CPU 16
42 #define IRQMP_REG_SIZE 256      /* Size of memory mapped registers */
43 
44 /* Memory mapped register offsets */
45 #define LEVEL_OFFSET     0x00
46 #define PENDING_OFFSET   0x04
47 #define FORCE0_OFFSET    0x08
48 #define CLEAR_OFFSET     0x0C
49 #define MP_STATUS_OFFSET 0x10
50 #define BROADCAST_OFFSET 0x14
51 #define MASK_OFFSET      0x40
52 #define FORCE_OFFSET     0x80
53 #define EXTENDED_OFFSET  0xC0
54 
55 /* Multiprocessor Status Register  */
56 #define MP_STATUS_CPU_STATUS_MASK ((1 << IRQMP_MAX_CPU)-2)
57 #define MP_STATUS_NCPU_SHIFT      28
58 
59 #define MAX_PILS 16
60 
61 OBJECT_DECLARE_SIMPLE_TYPE(IRQMP, GRLIB_IRQMP)
62 
63 typedef struct IRQMPState IRQMPState;
64 
65 struct IRQMP {
66     SysBusDevice parent_obj;
67 
68     MemoryRegion iomem;
69 
70     unsigned int ncpus;
71     IRQMPState *state;
72     qemu_irq start_signal[IRQMP_MAX_CPU];
73     qemu_irq irq;
74 };
75 
76 struct IRQMPState {
77     uint32_t level;
78     uint32_t pending;
79     uint32_t clear;
80     uint32_t mpstatus;
81     uint32_t broadcast;
82 
83     uint32_t mask[IRQMP_MAX_CPU];
84     uint32_t force[IRQMP_MAX_CPU];
85     uint32_t extended[IRQMP_MAX_CPU];
86 
87     IRQMP    *parent;
88 };
89 
90 static void grlib_irqmp_check_irqs(IRQMPState *state)
91 {
92     uint32_t      pend   = 0;
93     uint32_t      level0 = 0;
94     uint32_t      level1 = 0;
95 
96     assert(state != NULL);
97     assert(state->parent != NULL);
98 
99     /* IRQ for CPU 0 (no SMP support) */
100     pend = (state->pending | state->force[0])
101         & state->mask[0];
102 
103     level0 = pend & ~state->level;
104     level1 = pend &  state->level;
105 
106     trace_grlib_irqmp_check_irqs(state->pending, state->force[0],
107                                  state->mask[0], level1, level0);
108 
109     /* Trigger level1 interrupt first and level0 if there is no level1 */
110     qemu_set_irq(state->parent->irq, level1 ?: level0);
111 }
112 
113 static void grlib_irqmp_ack_mask(IRQMPState *state, uint32_t mask)
114 {
115     /* Clear registers */
116     state->pending  &= ~mask;
117     state->force[0] &= ~mask; /* Only CPU 0 (No SMP support) */
118 
119     grlib_irqmp_check_irqs(state);
120 }
121 
122 void grlib_irqmp_ack(DeviceState *dev, int intno)
123 {
124     IRQMP        *irqmp = GRLIB_IRQMP(dev);
125     IRQMPState   *state;
126     uint32_t      mask;
127 
128     state = irqmp->state;
129     assert(state != NULL);
130 
131     intno &= 15;
132     mask = 1 << intno;
133 
134     trace_grlib_irqmp_ack(intno);
135 
136     grlib_irqmp_ack_mask(state, mask);
137 }
138 
139 static void grlib_irqmp_set_irq(void *opaque, int irq, int level)
140 {
141     IRQMP      *irqmp = GRLIB_IRQMP(opaque);
142     IRQMPState *s;
143     int         i = 0;
144 
145     s = irqmp->state;
146     assert(s         != NULL);
147     assert(s->parent != NULL);
148 
149 
150     if (level) {
151         trace_grlib_irqmp_set_irq(irq);
152 
153         if (s->broadcast & 1 << irq) {
154             /* Broadcasted IRQ */
155             for (i = 0; i < IRQMP_MAX_CPU; i++) {
156                 s->force[i] |= 1 << irq;
157             }
158         } else {
159             s->pending |= 1 << irq;
160         }
161         grlib_irqmp_check_irqs(s);
162 
163     }
164 }
165 
166 static uint64_t grlib_irqmp_read(void *opaque, hwaddr addr,
167                                  unsigned size)
168 {
169     IRQMP      *irqmp = opaque;
170     IRQMPState *state;
171 
172     assert(irqmp != NULL);
173     state = irqmp->state;
174     assert(state != NULL);
175 
176     addr &= 0xff;
177 
178     /* global registers */
179     switch (addr) {
180     case LEVEL_OFFSET:
181         return state->level;
182 
183     case PENDING_OFFSET:
184         return state->pending;
185 
186     case FORCE0_OFFSET:
187         /* This register is an "alias" for the force register of CPU 0 */
188         return state->force[0];
189 
190     case CLEAR_OFFSET:
191         /* Always read as 0 */
192         return 0;
193 
194     case MP_STATUS_OFFSET:
195         return state->mpstatus;
196 
197     case BROADCAST_OFFSET:
198         return state->broadcast;
199 
200     default:
201         break;
202     }
203 
204     /* mask registers */
205     if (addr >= MASK_OFFSET && addr < FORCE_OFFSET) {
206         int cpu = (addr - MASK_OFFSET) / 4;
207         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
208 
209         return state->mask[cpu];
210     }
211 
212     /* force registers */
213     if (addr >= FORCE_OFFSET && addr < EXTENDED_OFFSET) {
214         int cpu = (addr - FORCE_OFFSET) / 4;
215         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
216 
217         return state->force[cpu];
218     }
219 
220     /* extended (not supported) */
221     if (addr >= EXTENDED_OFFSET && addr < IRQMP_REG_SIZE) {
222         int cpu = (addr - EXTENDED_OFFSET) / 4;
223         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
224 
225         return state->extended[cpu];
226     }
227 
228     trace_grlib_irqmp_readl_unknown(addr);
229     return 0;
230 }
231 
232 static void grlib_irqmp_write(void *opaque, hwaddr addr,
233                               uint64_t value, unsigned size)
234 {
235     IRQMP *irqmp = opaque;
236     IRQMPState *state;
237     int i;
238 
239     assert(irqmp != NULL);
240     state = irqmp->state;
241     assert(state != NULL);
242 
243     addr &= 0xff;
244 
245     /* global registers */
246     switch (addr) {
247     case LEVEL_OFFSET:
248         value &= 0xFFFF << 1; /* clean up the value */
249         state->level = value;
250         return;
251 
252     case PENDING_OFFSET:
253         /* Read Only */
254         return;
255 
256     case FORCE0_OFFSET:
257         /* This register is an "alias" for the force register of CPU 0 */
258 
259         value &= 0xFFFE; /* clean up the value */
260         state->force[0] = value;
261         grlib_irqmp_check_irqs(irqmp->state);
262         return;
263 
264     case CLEAR_OFFSET:
265         value &= ~1; /* clean up the value */
266         grlib_irqmp_ack_mask(state, value);
267         return;
268 
269     case MP_STATUS_OFFSET:
270         /*
271          * Writing and reading operations are reversed for the CPU status.
272          * Writing "1" will start the CPU, but reading "1" means that the CPU
273          * is power-down.
274          */
275         value &= MP_STATUS_CPU_STATUS_MASK;
276         for (i = 0; i < irqmp->ncpus; i++) {
277             if ((value >> i) & 1) {
278                 qemu_set_irq(irqmp->start_signal[i], 1);
279                 state->mpstatus &= ~(1 << i);
280             }
281         }
282         return;
283 
284     case BROADCAST_OFFSET:
285         value &= 0xFFFE; /* clean up the value */
286         state->broadcast = value;
287         return;
288 
289     default:
290         break;
291     }
292 
293     /* mask registers */
294     if (addr >= MASK_OFFSET && addr < FORCE_OFFSET) {
295         int cpu = (addr - MASK_OFFSET) / 4;
296         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
297 
298         value &= ~1; /* clean up the value */
299         state->mask[cpu] = value;
300         grlib_irqmp_check_irqs(irqmp->state);
301         return;
302     }
303 
304     /* force registers */
305     if (addr >= FORCE_OFFSET && addr < EXTENDED_OFFSET) {
306         int cpu = (addr - FORCE_OFFSET) / 4;
307         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
308 
309         uint32_t force = value & 0xFFFE;
310         uint32_t clear = (value >> 16) & 0xFFFE;
311         uint32_t old   = state->force[cpu];
312 
313         state->force[cpu] = (old | force) & ~clear;
314         grlib_irqmp_check_irqs(irqmp->state);
315         return;
316     }
317 
318     /* extended (not supported) */
319     if (addr >= EXTENDED_OFFSET && addr < IRQMP_REG_SIZE) {
320         int cpu = (addr - EXTENDED_OFFSET) / 4;
321         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
322 
323         value &= 0xF; /* clean up the value */
324         state->extended[cpu] = value;
325         return;
326     }
327 
328     trace_grlib_irqmp_writel_unknown(addr, value);
329 }
330 
331 static const MemoryRegionOps grlib_irqmp_ops = {
332     .read = grlib_irqmp_read,
333     .write = grlib_irqmp_write,
334     .endianness = DEVICE_NATIVE_ENDIAN,
335     .valid = {
336         .min_access_size = 4,
337         .max_access_size = 4,
338     },
339 };
340 
341 static void grlib_irqmp_reset(DeviceState *d)
342 {
343     IRQMP *irqmp = GRLIB_IRQMP(d);
344     assert(irqmp->state != NULL);
345 
346     memset(irqmp->state, 0, sizeof *irqmp->state);
347     irqmp->state->parent = irqmp;
348     irqmp->state->mpstatus = ((irqmp->ncpus - 1) << MP_STATUS_NCPU_SHIFT) |
349         ((1 << irqmp->ncpus) - 2);
350 }
351 
352 static void grlib_irqmp_realize(DeviceState *dev, Error **errp)
353 {
354     IRQMP *irqmp = GRLIB_IRQMP(dev);
355 
356     if ((!irqmp->ncpus) || (irqmp->ncpus > IRQMP_MAX_CPU)) {
357         error_setg(errp, "Invalid ncpus properties: "
358                    "%u, must be 0 < ncpus =< %u.", irqmp->ncpus,
359                    IRQMP_MAX_CPU);
360     }
361 
362     qdev_init_gpio_in(dev, grlib_irqmp_set_irq, MAX_PILS);
363 
364     /*
365      * Transitionning from 0 to 1 starts the CPUs. The opposite can't
366      * happen.
367      */
368     qdev_init_gpio_out_named(dev, irqmp->start_signal, "grlib-start-cpu",
369                              IRQMP_MAX_CPU);
370     qdev_init_gpio_out_named(dev, &irqmp->irq, "grlib-irq", 1);
371     memory_region_init_io(&irqmp->iomem, OBJECT(dev), &grlib_irqmp_ops, irqmp,
372                           "irqmp", IRQMP_REG_SIZE);
373 
374     irqmp->state = g_malloc0(sizeof *irqmp->state);
375 
376     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &irqmp->iomem);
377 }
378 
379 static Property grlib_irqmp_properties[] = {
380     DEFINE_PROP_UINT32("ncpus", IRQMP, ncpus, 1),
381     DEFINE_PROP_END_OF_LIST(),
382 };
383 
384 static void grlib_irqmp_class_init(ObjectClass *klass, void *data)
385 {
386     DeviceClass *dc = DEVICE_CLASS(klass);
387 
388     dc->realize = grlib_irqmp_realize;
389     dc->reset = grlib_irqmp_reset;
390     device_class_set_props(dc, grlib_irqmp_properties);
391 }
392 
393 static const TypeInfo grlib_irqmp_info = {
394     .name          = TYPE_GRLIB_IRQMP,
395     .parent        = TYPE_SYS_BUS_DEVICE,
396     .instance_size = sizeof(IRQMP),
397     .class_init    = grlib_irqmp_class_init,
398 };
399 
400 static void grlib_irqmp_register_types(void)
401 {
402     type_register_static(&grlib_irqmp_info);
403 }
404 
405 type_init(grlib_irqmp_register_types)
406