xref: /openbmc/qemu/hw/intc/mips_gic.c (revision 9dea2df8)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
7  * Authors: Sanjay Lal <sanjayl@kymasys.com>
8  *
9  * Copyright (C) 2016 Imagination Technologies
10  */
11 
12 #include "qemu/osdep.h"
13 #include "qemu/log.h"
14 #include "qapi/error.h"
15 #include "hw/hw.h"
16 #include "hw/sysbus.h"
17 #include "exec/memory.h"
18 #include "sysemu/sysemu.h"
19 #include "sysemu/kvm.h"
20 #include "kvm_mips.h"
21 #include "hw/intc/mips_gic.h"
22 
23 static void mips_gic_set_vp_irq(MIPSGICState *gic, int vp, int pin)
24 {
25     int ored_level = 0;
26     int i;
27 
28     /* ORing pending registers sharing same pin */
29     for (i = 0; i < gic->num_irq; i++) {
30         if ((gic->irq_state[i].map_pin & GIC_MAP_MSK) == pin &&
31                 gic->irq_state[i].map_vp == vp &&
32                 gic->irq_state[i].enabled) {
33             ored_level |= gic->irq_state[i].pending;
34         }
35         if (ored_level) {
36             /* no need to iterate all interrupts */
37             break;
38         }
39     }
40     if (((gic->vps[vp].compare_map & GIC_MAP_MSK) == pin) &&
41             (gic->vps[vp].mask & GIC_VP_MASK_CMP_MSK)) {
42         /* ORing with local pending register (count/compare) */
43         ored_level |= (gic->vps[vp].pend & GIC_VP_MASK_CMP_MSK) >>
44                       GIC_VP_MASK_CMP_SHF;
45     }
46     if (kvm_enabled())  {
47         kvm_mips_set_ipi_interrupt(mips_env_get_cpu(gic->vps[vp].env),
48                                    pin + GIC_CPU_PIN_OFFSET,
49                                    ored_level);
50     } else {
51         qemu_set_irq(gic->vps[vp].env->irq[pin + GIC_CPU_PIN_OFFSET],
52                      ored_level);
53     }
54 }
55 
56 static void gic_update_pin_for_irq(MIPSGICState *gic, int n_IRQ)
57 {
58     int vp = gic->irq_state[n_IRQ].map_vp;
59     int pin = gic->irq_state[n_IRQ].map_pin & GIC_MAP_MSK;
60 
61     if (vp < 0 || vp >= gic->num_vps) {
62         return;
63     }
64     mips_gic_set_vp_irq(gic, vp, pin);
65 }
66 
67 static void gic_set_irq(void *opaque, int n_IRQ, int level)
68 {
69     MIPSGICState *gic = (MIPSGICState *) opaque;
70 
71     gic->irq_state[n_IRQ].pending = (uint8_t) level;
72     if (!gic->irq_state[n_IRQ].enabled) {
73         /* GIC interrupt source disabled */
74         return;
75     }
76     gic_update_pin_for_irq(gic, n_IRQ);
77 }
78 
79 #define OFFSET_CHECK(c)                         \
80     do {                                        \
81         if (!(c)) {                             \
82             goto bad_offset;                    \
83         }                                       \
84     } while (0)
85 
86 /* GIC Read VP Local/Other Registers */
87 static uint64_t gic_read_vp(MIPSGICState *gic, uint32_t vp_index, hwaddr addr,
88                             unsigned size)
89 {
90     switch (addr) {
91     case GIC_VP_CTL_OFS:
92         return gic->vps[vp_index].ctl;
93     case GIC_VP_PEND_OFS:
94         mips_gictimer_get_sh_count(gic->gic_timer);
95         return gic->vps[vp_index].pend;
96     case GIC_VP_MASK_OFS:
97         return gic->vps[vp_index].mask;
98     case GIC_VP_COMPARE_MAP_OFS:
99         return gic->vps[vp_index].compare_map;
100     case GIC_VP_OTHER_ADDR_OFS:
101         return gic->vps[vp_index].other_addr;
102     case GIC_VP_IDENT_OFS:
103         return vp_index;
104     case GIC_VP_COMPARE_LO_OFS:
105         return mips_gictimer_get_vp_compare(gic->gic_timer, vp_index);
106     case GIC_VP_COMPARE_HI_OFS:
107         return 0;
108     default:
109         qemu_log_mask(LOG_UNIMP, "Read %d bytes at GIC offset LOCAL/OTHER 0x%"
110                       PRIx64 "\n", size, addr);
111         break;
112     }
113     return 0;
114 }
115 
116 static uint64_t gic_read(void *opaque, hwaddr addr, unsigned size)
117 {
118     MIPSGICState *gic = (MIPSGICState *) opaque;
119     uint32_t vp_index = current_cpu->cpu_index;
120     uint64_t ret = 0;
121     int i, base, irq_src;
122     uint32_t other_index;
123 
124     switch (addr) {
125     case GIC_SH_CONFIG_OFS:
126         ret = gic->sh_config | (mips_gictimer_get_countstop(gic->gic_timer) <<
127                                GIC_SH_CONFIG_COUNTSTOP_SHF);
128         break;
129     case GIC_SH_COUNTERLO_OFS:
130         ret = mips_gictimer_get_sh_count(gic->gic_timer);
131         break;
132     case GIC_SH_COUNTERHI_OFS:
133         ret = 0;
134         break;
135     case GIC_SH_PEND_OFS ... GIC_SH_PEND_LAST_OFS:
136         /* each bit represents pending status for an interrupt pin */
137         base = (addr - GIC_SH_PEND_OFS) * 8;
138         OFFSET_CHECK((base + size * 8) <= gic->num_irq);
139         for (i = 0; i < size * 8; i++) {
140             ret |= (uint64_t) (gic->irq_state[base + i].pending) << i;
141         }
142         break;
143     case GIC_SH_MASK_OFS ... GIC_SH_MASK_LAST_OFS:
144         /* each bit represents status for an interrupt pin */
145         base = (addr - GIC_SH_MASK_OFS) * 8;
146         OFFSET_CHECK((base + size * 8) <= gic->num_irq);
147         for (i = 0; i < size * 8; i++) {
148             ret |= (uint64_t) (gic->irq_state[base + i].enabled) << i;
149         }
150         break;
151     case GIC_SH_MAP0_PIN_OFS ... GIC_SH_MAP255_PIN_OFS:
152         /* 32 bits per a pin */
153         irq_src = (addr - GIC_SH_MAP0_PIN_OFS) / 4;
154         OFFSET_CHECK(irq_src < gic->num_irq);
155         ret = gic->irq_state[irq_src].map_pin;
156         break;
157     case GIC_SH_MAP0_VP_OFS ... GIC_SH_MAP255_VP_LAST_OFS:
158         /* up to 32 bytes per a pin */
159         irq_src = (addr - GIC_SH_MAP0_VP_OFS) / 32;
160         OFFSET_CHECK(irq_src < gic->num_irq);
161         if ((gic->irq_state[irq_src].map_vp) >= 0) {
162             ret = (uint64_t) 1 << (gic->irq_state[irq_src].map_vp);
163         } else {
164             ret = 0;
165         }
166         break;
167     /* VP-Local Register */
168     case VP_LOCAL_SECTION_OFS ... (VP_LOCAL_SECTION_OFS + GIC_VL_BRK_GROUP):
169         ret = gic_read_vp(gic, vp_index, addr - VP_LOCAL_SECTION_OFS, size);
170         break;
171     /* VP-Other Register */
172     case VP_OTHER_SECTION_OFS ... (VP_OTHER_SECTION_OFS + GIC_VL_BRK_GROUP):
173         other_index = gic->vps[vp_index].other_addr;
174         ret = gic_read_vp(gic, other_index, addr - VP_OTHER_SECTION_OFS, size);
175         break;
176     /* User-Mode Visible section */
177     case USM_VISIBLE_SECTION_OFS + GIC_USER_MODE_COUNTERLO:
178         ret = mips_gictimer_get_sh_count(gic->gic_timer);
179         break;
180     case USM_VISIBLE_SECTION_OFS + GIC_USER_MODE_COUNTERHI:
181         ret = 0;
182         break;
183     default:
184         qemu_log_mask(LOG_UNIMP, "Read %d bytes at GIC offset 0x%" PRIx64 "\n",
185                       size, addr);
186         break;
187     }
188     return ret;
189 bad_offset:
190     qemu_log_mask(LOG_GUEST_ERROR, "Wrong GIC offset at 0x%" PRIx64 "\n", addr);
191     return 0;
192 }
193 
194 static void gic_timer_expire_cb(void *opaque, uint32_t vp_index)
195 {
196     MIPSGICState *gic = opaque;
197 
198     gic->vps[vp_index].pend |= (1 << GIC_LOCAL_INT_COMPARE);
199     if (gic->vps[vp_index].pend &
200             (gic->vps[vp_index].mask & GIC_VP_MASK_CMP_MSK)) {
201         if (gic->vps[vp_index].compare_map & GIC_MAP_TO_PIN_MSK) {
202             /* it is safe to set the irq high regardless of other GIC IRQs */
203             uint32_t pin = (gic->vps[vp_index].compare_map & GIC_MAP_MSK);
204             qemu_irq_raise(gic->vps[vp_index].env->irq
205                            [pin + GIC_CPU_PIN_OFFSET]);
206         }
207     }
208 }
209 
210 static void gic_timer_store_vp_compare(MIPSGICState *gic, uint32_t vp_index,
211                                        uint64_t compare)
212 {
213     gic->vps[vp_index].pend &= ~(1 << GIC_LOCAL_INT_COMPARE);
214     if (gic->vps[vp_index].compare_map & GIC_MAP_TO_PIN_MSK) {
215         uint32_t pin = (gic->vps[vp_index].compare_map & GIC_MAP_MSK);
216         mips_gic_set_vp_irq(gic, vp_index, pin);
217     }
218     mips_gictimer_store_vp_compare(gic->gic_timer, vp_index, compare);
219 }
220 
221 /* GIC Write VP Local/Other Registers */
222 static void gic_write_vp(MIPSGICState *gic, uint32_t vp_index, hwaddr addr,
223                               uint64_t data, unsigned size)
224 {
225     switch (addr) {
226     case GIC_VP_CTL_OFS:
227         /* EIC isn't supported */
228         break;
229     case GIC_VP_RMASK_OFS:
230         gic->vps[vp_index].mask &= ~(data & GIC_VP_SET_RESET_MSK) &
231                                    GIC_VP_SET_RESET_MSK;
232         break;
233     case GIC_VP_SMASK_OFS:
234         gic->vps[vp_index].mask |= data & GIC_VP_SET_RESET_MSK;
235         break;
236     case GIC_VP_COMPARE_MAP_OFS:
237         /* EIC isn't supported */
238         OFFSET_CHECK((data & GIC_MAP_MSK) <= GIC_CPU_INT_MAX);
239         gic->vps[vp_index].compare_map = data & GIC_MAP_TO_PIN_REG_MSK;
240         break;
241     case GIC_VP_OTHER_ADDR_OFS:
242         OFFSET_CHECK(data < gic->num_vps);
243         gic->vps[vp_index].other_addr = data;
244         break;
245     case GIC_VP_COMPARE_LO_OFS:
246         gic_timer_store_vp_compare(gic, vp_index, data);
247         break;
248     default:
249         qemu_log_mask(LOG_UNIMP, "Write %d bytes at GIC offset LOCAL/OTHER "
250                       "0x%" PRIx64" 0x%08" PRIx64 "\n", size, addr, data);
251         break;
252     }
253     return;
254 bad_offset:
255     qemu_log_mask(LOG_GUEST_ERROR, "Wrong GIC offset at 0x%" PRIx64 "\n", addr);
256     return;
257 }
258 
259 static void gic_write(void *opaque, hwaddr addr, uint64_t data, unsigned size)
260 {
261     int intr;
262     MIPSGICState *gic = (MIPSGICState *) opaque;
263     uint32_t vp_index = current_cpu->cpu_index;
264     int i, base, irq_src;
265     uint32_t other_index;
266 
267     switch (addr) {
268     case GIC_SH_CONFIG_OFS:
269         {
270             uint32_t pre_cntstop = mips_gictimer_get_countstop(gic->gic_timer);
271             uint32_t new_cntstop = (data & GIC_SH_CONFIG_COUNTSTOP_MSK) >>
272                                    GIC_SH_CONFIG_COUNTSTOP_SHF;
273             if (pre_cntstop != new_cntstop) {
274                 if (new_cntstop == 1) {
275                     mips_gictimer_stop_count(gic->gic_timer);
276                 } else {
277                     mips_gictimer_start_count(gic->gic_timer);
278                 }
279             }
280         }
281         break;
282     case GIC_SH_COUNTERLO_OFS:
283         if (mips_gictimer_get_countstop(gic->gic_timer)) {
284             mips_gictimer_store_sh_count(gic->gic_timer, data);
285         }
286         break;
287     case GIC_SH_RMASK_OFS ... GIC_SH_RMASK_LAST_OFS:
288         /* up to 64 bits per a pin */
289         base = (addr - GIC_SH_RMASK_OFS) * 8;
290         OFFSET_CHECK((base + size * 8) <= gic->num_irq);
291         for (i = 0; i < size * 8; i++) {
292             gic->irq_state[base + i].enabled &= !((data >> i) & 1);
293             gic_update_pin_for_irq(gic, base + i);
294         }
295         break;
296     case GIC_SH_WEDGE_OFS:
297         /* Figure out which VP/HW Interrupt this maps to */
298         intr = data & ~GIC_SH_WEDGE_RW_MSK;
299         /* Mask/Enabled Checks */
300         OFFSET_CHECK(intr < gic->num_irq);
301         if (data & GIC_SH_WEDGE_RW_MSK) {
302             gic_set_irq(gic, intr, 1);
303         } else {
304             gic_set_irq(gic, intr, 0);
305         }
306         break;
307     case GIC_SH_SMASK_OFS ... GIC_SH_SMASK_LAST_OFS:
308         /* up to 64 bits per a pin */
309         base = (addr - GIC_SH_SMASK_OFS) * 8;
310         OFFSET_CHECK((base + size * 8) <= gic->num_irq);
311         for (i = 0; i < size * 8; i++) {
312             gic->irq_state[base + i].enabled |= (data >> i) & 1;
313             gic_update_pin_for_irq(gic, base + i);
314         }
315         break;
316     case GIC_SH_MAP0_PIN_OFS ... GIC_SH_MAP255_PIN_OFS:
317         /* 32 bits per a pin */
318         irq_src = (addr - GIC_SH_MAP0_PIN_OFS) / 4;
319         OFFSET_CHECK(irq_src < gic->num_irq);
320         /* EIC isn't supported */
321         OFFSET_CHECK((data & GIC_MAP_MSK) <= GIC_CPU_INT_MAX);
322         gic->irq_state[irq_src].map_pin = data & GIC_MAP_TO_PIN_REG_MSK;
323         break;
324     case GIC_SH_MAP0_VP_OFS ... GIC_SH_MAP255_VP_LAST_OFS:
325         /* up to 32 bytes per a pin */
326         irq_src = (addr - GIC_SH_MAP0_VP_OFS) / 32;
327         OFFSET_CHECK(irq_src < gic->num_irq);
328         data = data ? ctz64(data) : -1;
329         OFFSET_CHECK(data < gic->num_vps);
330         gic->irq_state[irq_src].map_vp = data;
331         break;
332     case VP_LOCAL_SECTION_OFS ... (VP_LOCAL_SECTION_OFS + GIC_VL_BRK_GROUP):
333         gic_write_vp(gic, vp_index, addr - VP_LOCAL_SECTION_OFS, data, size);
334         break;
335     case VP_OTHER_SECTION_OFS ... (VP_OTHER_SECTION_OFS + GIC_VL_BRK_GROUP):
336         other_index = gic->vps[vp_index].other_addr;
337         gic_write_vp(gic, other_index, addr - VP_OTHER_SECTION_OFS, data, size);
338         break;
339     case USM_VISIBLE_SECTION_OFS + GIC_USER_MODE_COUNTERLO:
340     case USM_VISIBLE_SECTION_OFS + GIC_USER_MODE_COUNTERHI:
341         /* do nothing. Read-only section */
342         break;
343     default:
344         qemu_log_mask(LOG_UNIMP, "Write %d bytes at GIC offset 0x%" PRIx64
345                       " 0x%08" PRIx64 "\n", size, addr, data);
346         break;
347     }
348     return;
349 bad_offset:
350     qemu_log_mask(LOG_GUEST_ERROR, "Wrong GIC offset at 0x%" PRIx64 "\n", addr);
351 }
352 
353 static void gic_reset(void *opaque)
354 {
355     int i;
356     MIPSGICState *gic = (MIPSGICState *) opaque;
357     int numintrs = (gic->num_irq / 8) - 1;
358 
359     gic->sh_config = /* COUNTSTOP = 0 it is accessible via MIPSGICTimer*/
360                      /* CounterHi not implemented */
361                      (0            << GIC_SH_CONFIG_COUNTBITS_SHF) |
362                      (numintrs     << GIC_SH_CONFIG_NUMINTRS_SHF)  |
363                      (gic->num_vps << GIC_SH_CONFIG_PVPS_SHF);
364     for (i = 0; i < gic->num_vps; i++) {
365         gic->vps[i].ctl         = 0x0;
366         gic->vps[i].pend        = 0x0;
367         /* PERFCNT, TIMER and WD not implemented */
368         gic->vps[i].mask        = 0x32;
369         gic->vps[i].compare_map = GIC_MAP_TO_PIN_MSK;
370         mips_gictimer_store_vp_compare(gic->gic_timer, i, 0xffffffff);
371         gic->vps[i].other_addr  = 0x0;
372     }
373     for (i = 0; i < gic->num_irq; i++) {
374         gic->irq_state[i].enabled = 0;
375         gic->irq_state[i].pending = 0;
376         gic->irq_state[i].map_pin = GIC_MAP_TO_PIN_MSK;
377         gic->irq_state[i].map_vp  = -1;
378     }
379     mips_gictimer_store_sh_count(gic->gic_timer, 0);
380     /* COUNTSTOP = 0 */
381     mips_gictimer_start_count(gic->gic_timer);
382 }
383 
384 static const MemoryRegionOps gic_ops = {
385     .read = gic_read,
386     .write = gic_write,
387     .endianness = DEVICE_NATIVE_ENDIAN,
388     .impl = {
389         .max_access_size = 8,
390     },
391 };
392 
393 static void mips_gic_init(Object *obj)
394 {
395     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
396     MIPSGICState *s = MIPS_GIC(obj);
397 
398     memory_region_init_io(&s->mr, OBJECT(s), &gic_ops, s,
399                           "mips-gic", GIC_ADDRSPACE_SZ);
400     sysbus_init_mmio(sbd, &s->mr);
401     qemu_register_reset(gic_reset, s);
402 }
403 
404 static void mips_gic_realize(DeviceState *dev, Error **errp)
405 {
406     MIPSGICState *s = MIPS_GIC(dev);
407     CPUState *cs = first_cpu;
408     int i;
409 
410     if (s->num_vps > GIC_MAX_VPS) {
411         error_setg(errp, "Exceeded maximum CPUs %d", s->num_vps);
412         return;
413     }
414     if ((s->num_irq > GIC_MAX_INTRS) || (s->num_irq % 8) || (s->num_irq <= 0)) {
415         error_setg(errp, "GIC supports up to %d external interrupts in "
416                    "multiples of 8 : %d", GIC_MAX_INTRS, s->num_irq);
417         return;
418     }
419     s->vps = g_new(MIPSGICVPState, s->num_vps);
420     s->irq_state = g_new(MIPSGICIRQState, s->num_irq);
421     /* Register the env for all VPs with the GIC */
422     for (i = 0; i < s->num_vps; i++) {
423         if (cs != NULL) {
424             s->vps[i].env = cs->env_ptr;
425             cs = CPU_NEXT(cs);
426         } else {
427             error_setg(errp,
428                "Unable to initialize GIC, CPUState for CPU#%d not valid.", i);
429             return;
430         }
431     }
432     s->gic_timer = mips_gictimer_init(s, s->num_vps, gic_timer_expire_cb);
433     qdev_init_gpio_in(dev, gic_set_irq, s->num_irq);
434     for (i = 0; i < s->num_irq; i++) {
435         s->irq_state[i].irq = qdev_get_gpio_in(dev, i);
436     }
437 }
438 
439 static Property mips_gic_properties[] = {
440     DEFINE_PROP_INT32("num-vp", MIPSGICState, num_vps, 1),
441     DEFINE_PROP_INT32("num-irq", MIPSGICState, num_irq, 256),
442     DEFINE_PROP_END_OF_LIST(),
443 };
444 
445 static void mips_gic_class_init(ObjectClass *klass, void *data)
446 {
447     DeviceClass *dc = DEVICE_CLASS(klass);
448 
449     dc->props = mips_gic_properties;
450     dc->realize = mips_gic_realize;
451 }
452 
453 static const TypeInfo mips_gic_info = {
454     .name          = TYPE_MIPS_GIC,
455     .parent        = TYPE_SYS_BUS_DEVICE,
456     .instance_size = sizeof(MIPSGICState),
457     .instance_init = mips_gic_init,
458     .class_init    = mips_gic_class_init,
459 };
460 
461 static void mips_gic_register_types(void)
462 {
463     type_register_static(&mips_gic_info);
464 }
465 
466 type_init(mips_gic_register_types)
467