1 /*
2  * QEMU PIIX PCI ISA Bridge Emulation
3  *
4  * Copyright (c) 2006 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/range.h"
27 #include "hw/southbridge/piix.h"
28 #include "hw/irq.h"
29 #include "hw/isa/isa.h"
30 #include "hw/xen/xen.h"
31 #include "sysemu/xen.h"
32 #include "sysemu/reset.h"
33 #include "sysemu/runstate.h"
34 #include "migration/vmstate.h"
35 
36 #define XEN_PIIX_NUM_PIRQS      128ULL
37 
38 #define TYPE_PIIX3_DEVICE "PIIX3"
39 #define TYPE_PIIX3_XEN_DEVICE "PIIX3-xen"
40 
41 static void piix3_set_irq_pic(PIIX3State *piix3, int pic_irq)
42 {
43     qemu_set_irq(piix3->pic[pic_irq],
44                  !!(piix3->pic_levels &
45                     (((1ULL << PIIX_NUM_PIRQS) - 1) <<
46                      (pic_irq * PIIX_NUM_PIRQS))));
47 }
48 
49 static void piix3_set_irq_level_internal(PIIX3State *piix3, int pirq, int level)
50 {
51     int pic_irq;
52     uint64_t mask;
53 
54     pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
55     if (pic_irq >= PIIX_NUM_PIC_IRQS) {
56         return;
57     }
58 
59     mask = 1ULL << ((pic_irq * PIIX_NUM_PIRQS) + pirq);
60     piix3->pic_levels &= ~mask;
61     piix3->pic_levels |= mask * !!level;
62 }
63 
64 static void piix3_set_irq_level(PIIX3State *piix3, int pirq, int level)
65 {
66     int pic_irq;
67 
68     pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
69     if (pic_irq >= PIIX_NUM_PIC_IRQS) {
70         return;
71     }
72 
73     piix3_set_irq_level_internal(piix3, pirq, level);
74 
75     piix3_set_irq_pic(piix3, pic_irq);
76 }
77 
78 static void piix3_set_irq(void *opaque, int pirq, int level)
79 {
80     PIIX3State *piix3 = opaque;
81     piix3_set_irq_level(piix3, pirq, level);
82 }
83 
84 static PCIINTxRoute piix3_route_intx_pin_to_irq(void *opaque, int pin)
85 {
86     PIIX3State *piix3 = opaque;
87     int irq = piix3->dev.config[PIIX_PIRQCA + pin];
88     PCIINTxRoute route;
89 
90     if (irq < PIIX_NUM_PIC_IRQS) {
91         route.mode = PCI_INTX_ENABLED;
92         route.irq = irq;
93     } else {
94         route.mode = PCI_INTX_DISABLED;
95         route.irq = -1;
96     }
97     return route;
98 }
99 
100 /* irq routing is changed. so rebuild bitmap */
101 static void piix3_update_irq_levels(PIIX3State *piix3)
102 {
103     PCIBus *bus = pci_get_bus(&piix3->dev);
104     int pirq;
105 
106     piix3->pic_levels = 0;
107     for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
108         piix3_set_irq_level(piix3, pirq, pci_bus_get_irq_level(bus, pirq));
109     }
110 }
111 
112 static void piix3_write_config(PCIDevice *dev,
113                                uint32_t address, uint32_t val, int len)
114 {
115     pci_default_write_config(dev, address, val, len);
116     if (ranges_overlap(address, len, PIIX_PIRQCA, 4)) {
117         PIIX3State *piix3 = PIIX3_PCI_DEVICE(dev);
118         int pic_irq;
119 
120         pci_bus_fire_intx_routing_notifier(pci_get_bus(&piix3->dev));
121         piix3_update_irq_levels(piix3);
122         for (pic_irq = 0; pic_irq < PIIX_NUM_PIC_IRQS; pic_irq++) {
123             piix3_set_irq_pic(piix3, pic_irq);
124         }
125     }
126 }
127 
128 static void piix3_write_config_xen(PCIDevice *dev,
129                                    uint32_t address, uint32_t val, int len)
130 {
131     xen_piix_pci_write_config_client(address, val, len);
132     piix3_write_config(dev, address, val, len);
133 }
134 
135 static void piix3_reset(void *opaque)
136 {
137     PIIX3State *d = opaque;
138     uint8_t *pci_conf = d->dev.config;
139 
140     pci_conf[0x04] = 0x07; /* master, memory and I/O */
141     pci_conf[0x05] = 0x00;
142     pci_conf[0x06] = 0x00;
143     pci_conf[0x07] = 0x02; /* PCI_status_devsel_medium */
144     pci_conf[0x4c] = 0x4d;
145     pci_conf[0x4e] = 0x03;
146     pci_conf[0x4f] = 0x00;
147     pci_conf[0x60] = 0x80;
148     pci_conf[0x61] = 0x80;
149     pci_conf[0x62] = 0x80;
150     pci_conf[0x63] = 0x80;
151     pci_conf[0x69] = 0x02;
152     pci_conf[0x70] = 0x80;
153     pci_conf[0x76] = 0x0c;
154     pci_conf[0x77] = 0x0c;
155     pci_conf[0x78] = 0x02;
156     pci_conf[0x79] = 0x00;
157     pci_conf[0x80] = 0x00;
158     pci_conf[0x82] = 0x00;
159     pci_conf[0xa0] = 0x08;
160     pci_conf[0xa2] = 0x00;
161     pci_conf[0xa3] = 0x00;
162     pci_conf[0xa4] = 0x00;
163     pci_conf[0xa5] = 0x00;
164     pci_conf[0xa6] = 0x00;
165     pci_conf[0xa7] = 0x00;
166     pci_conf[0xa8] = 0x0f;
167     pci_conf[0xaa] = 0x00;
168     pci_conf[0xab] = 0x00;
169     pci_conf[0xac] = 0x00;
170     pci_conf[0xae] = 0x00;
171 
172     d->pic_levels = 0;
173     d->rcr = 0;
174 }
175 
176 static int piix3_post_load(void *opaque, int version_id)
177 {
178     PIIX3State *piix3 = opaque;
179     int pirq;
180 
181     /*
182      * Because the i8259 has not been deserialized yet, qemu_irq_raise
183      * might bring the system to a different state than the saved one;
184      * for example, the interrupt could be masked but the i8259 would
185      * not know that yet and would trigger an interrupt in the CPU.
186      *
187      * Here, we update irq levels without raising the interrupt.
188      * Interrupt state will be deserialized separately through the i8259.
189      */
190     piix3->pic_levels = 0;
191     for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
192         piix3_set_irq_level_internal(piix3, pirq,
193             pci_bus_get_irq_level(pci_get_bus(&piix3->dev), pirq));
194     }
195     return 0;
196 }
197 
198 static int piix3_pre_save(void *opaque)
199 {
200     int i;
201     PIIX3State *piix3 = opaque;
202 
203     for (i = 0; i < ARRAY_SIZE(piix3->pci_irq_levels_vmstate); i++) {
204         piix3->pci_irq_levels_vmstate[i] =
205             pci_bus_get_irq_level(pci_get_bus(&piix3->dev), i);
206     }
207 
208     return 0;
209 }
210 
211 static bool piix3_rcr_needed(void *opaque)
212 {
213     PIIX3State *piix3 = opaque;
214 
215     return (piix3->rcr != 0);
216 }
217 
218 static const VMStateDescription vmstate_piix3_rcr = {
219     .name = "PIIX3/rcr",
220     .version_id = 1,
221     .minimum_version_id = 1,
222     .needed = piix3_rcr_needed,
223     .fields = (VMStateField[]) {
224         VMSTATE_UINT8(rcr, PIIX3State),
225         VMSTATE_END_OF_LIST()
226     }
227 };
228 
229 static const VMStateDescription vmstate_piix3 = {
230     .name = "PIIX3",
231     .version_id = 3,
232     .minimum_version_id = 2,
233     .post_load = piix3_post_load,
234     .pre_save = piix3_pre_save,
235     .fields = (VMStateField[]) {
236         VMSTATE_PCI_DEVICE(dev, PIIX3State),
237         VMSTATE_INT32_ARRAY_V(pci_irq_levels_vmstate, PIIX3State,
238                               PIIX_NUM_PIRQS, 3),
239         VMSTATE_END_OF_LIST()
240     },
241     .subsections = (const VMStateDescription*[]) {
242         &vmstate_piix3_rcr,
243         NULL
244     }
245 };
246 
247 
248 static void rcr_write(void *opaque, hwaddr addr, uint64_t val, unsigned len)
249 {
250     PIIX3State *d = opaque;
251 
252     if (val & 4) {
253         qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
254         return;
255     }
256     d->rcr = val & 2; /* keep System Reset type only */
257 }
258 
259 static uint64_t rcr_read(void *opaque, hwaddr addr, unsigned len)
260 {
261     PIIX3State *d = opaque;
262 
263     return d->rcr;
264 }
265 
266 static const MemoryRegionOps rcr_ops = {
267     .read = rcr_read,
268     .write = rcr_write,
269     .endianness = DEVICE_LITTLE_ENDIAN
270 };
271 
272 static void piix3_realize(PCIDevice *dev, Error **errp)
273 {
274     PIIX3State *d = PIIX3_PCI_DEVICE(dev);
275 
276     if (!isa_bus_new(DEVICE(d), get_system_memory(),
277                      pci_address_space_io(dev), errp)) {
278         return;
279     }
280 
281     memory_region_init_io(&d->rcr_mem, OBJECT(dev), &rcr_ops, d,
282                           "piix3-reset-control", 1);
283     memory_region_add_subregion_overlap(pci_address_space_io(dev),
284                                         PIIX_RCR_IOPORT, &d->rcr_mem, 1);
285 
286     qemu_register_reset(piix3_reset, d);
287 }
288 
289 static void pci_piix3_class_init(ObjectClass *klass, void *data)
290 {
291     DeviceClass *dc = DEVICE_CLASS(klass);
292     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
293 
294     dc->desc        = "ISA bridge";
295     dc->vmsd        = &vmstate_piix3;
296     dc->hotpluggable   = false;
297     k->realize      = piix3_realize;
298     k->vendor_id    = PCI_VENDOR_ID_INTEL;
299     /* 82371SB PIIX3 PCI-to-ISA bridge (Step A1) */
300     k->device_id    = PCI_DEVICE_ID_INTEL_82371SB_0;
301     k->class_id     = PCI_CLASS_BRIDGE_ISA;
302     /*
303      * Reason: part of PIIX3 southbridge, needs to be wired up by
304      * pc_piix.c's pc_init1()
305      */
306     dc->user_creatable = false;
307 }
308 
309 static const TypeInfo piix3_pci_type_info = {
310     .name = TYPE_PIIX3_PCI_DEVICE,
311     .parent = TYPE_PCI_DEVICE,
312     .instance_size = sizeof(PIIX3State),
313     .abstract = true,
314     .class_init = pci_piix3_class_init,
315     .interfaces = (InterfaceInfo[]) {
316         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
317         { },
318     },
319 };
320 
321 static void piix3_class_init(ObjectClass *klass, void *data)
322 {
323     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
324 
325     k->config_write = piix3_write_config;
326 }
327 
328 static const TypeInfo piix3_info = {
329     .name          = TYPE_PIIX3_DEVICE,
330     .parent        = TYPE_PIIX3_PCI_DEVICE,
331     .class_init    = piix3_class_init,
332 };
333 
334 static void piix3_xen_class_init(ObjectClass *klass, void *data)
335 {
336     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
337 
338     k->config_write = piix3_write_config_xen;
339 };
340 
341 static const TypeInfo piix3_xen_info = {
342     .name          = TYPE_PIIX3_XEN_DEVICE,
343     .parent        = TYPE_PIIX3_PCI_DEVICE,
344     .class_init    = piix3_xen_class_init,
345 };
346 
347 static void piix3_register_types(void)
348 {
349     type_register_static(&piix3_pci_type_info);
350     type_register_static(&piix3_info);
351     type_register_static(&piix3_xen_info);
352 }
353 
354 type_init(piix3_register_types)
355 
356 /*
357  * Return the global irq number corresponding to a given device irq
358  * pin. We could also use the bus number to have a more precise mapping.
359  */
360 static int pci_slot_get_pirq(PCIDevice *pci_dev, int pci_intx)
361 {
362     int slot_addend;
363     slot_addend = PCI_SLOT(pci_dev->devfn) - 1;
364     return (pci_intx + slot_addend) & 3;
365 }
366 
367 PIIX3State *piix3_create(PCIBus *pci_bus, ISABus **isa_bus)
368 {
369     PIIX3State *piix3;
370     PCIDevice *pci_dev;
371 
372     /*
373      * Xen supports additional interrupt routes from the PCI devices to
374      * the IOAPIC: the four pins of each PCI device on the bus are also
375      * connected to the IOAPIC directly.
376      * These additional routes can be discovered through ACPI.
377      */
378     if (xen_enabled()) {
379         pci_dev = pci_create_simple_multifunction(pci_bus, -1, true,
380                                                   TYPE_PIIX3_XEN_DEVICE);
381         piix3 = PIIX3_PCI_DEVICE(pci_dev);
382         pci_bus_irqs(pci_bus, xen_piix3_set_irq, xen_pci_slot_get_pirq,
383                      piix3, XEN_PIIX_NUM_PIRQS);
384     } else {
385         pci_dev = pci_create_simple_multifunction(pci_bus, -1, true,
386                                                   TYPE_PIIX3_DEVICE);
387         piix3 = PIIX3_PCI_DEVICE(pci_dev);
388         pci_bus_irqs(pci_bus, piix3_set_irq, pci_slot_get_pirq,
389                      piix3, PIIX_NUM_PIRQS);
390         pci_bus_set_route_irq_fn(pci_bus, piix3_route_intx_pin_to_irq);
391     }
392     *isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(piix3), "isa.0"));
393 
394     return piix3;
395 }
396