xref: /openbmc/qemu/hw/pci/pci_bridge.c (revision 3588185b)
1 /*
2  * QEMU PCI bus manager
3  *
4  * Copyright (c) 2004 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 dea
8 
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
22 
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 /*
27  * split out from pci.c
28  * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
29  *                    VA Linux Systems Japan K.K.
30  */
31 
32 #include "hw/pci/pci_bridge.h"
33 #include "hw/pci/pci_bus.h"
34 #include "qemu/range.h"
35 
36 /* PCI bridge subsystem vendor ID helper functions */
37 #define PCI_SSVID_SIZEOF        8
38 #define PCI_SSVID_SVID          4
39 #define PCI_SSVID_SSID          6
40 
41 int pci_bridge_ssvid_init(PCIDevice *dev, uint8_t offset,
42                           uint16_t svid, uint16_t ssid)
43 {
44     int pos;
45     pos = pci_add_capability(dev, PCI_CAP_ID_SSVID, offset, PCI_SSVID_SIZEOF);
46     if (pos < 0) {
47         return pos;
48     }
49 
50     pci_set_word(dev->config + pos + PCI_SSVID_SVID, svid);
51     pci_set_word(dev->config + pos + PCI_SSVID_SSID, ssid);
52     return pos;
53 }
54 
55 /* Accessor function to get parent bridge device from pci bus. */
56 PCIDevice *pci_bridge_get_device(PCIBus *bus)
57 {
58     return bus->parent_dev;
59 }
60 
61 /* Accessor function to get secondary bus from pci-to-pci bridge device */
62 PCIBus *pci_bridge_get_sec_bus(PCIBridge *br)
63 {
64     return &br->sec_bus;
65 }
66 
67 static uint32_t pci_config_get_io_base(const PCIDevice *d,
68                                        uint32_t base, uint32_t base_upper16)
69 {
70     uint32_t val;
71 
72     val = ((uint32_t)d->config[base] & PCI_IO_RANGE_MASK) << 8;
73     if (d->config[base] & PCI_IO_RANGE_TYPE_32) {
74         val |= (uint32_t)pci_get_word(d->config + base_upper16) << 16;
75     }
76     return val;
77 }
78 
79 static pcibus_t pci_config_get_memory_base(const PCIDevice *d, uint32_t base)
80 {
81     return ((pcibus_t)pci_get_word(d->config + base) & PCI_MEMORY_RANGE_MASK)
82         << 16;
83 }
84 
85 static pcibus_t pci_config_get_pref_base(const PCIDevice *d,
86                                          uint32_t base, uint32_t upper)
87 {
88     pcibus_t tmp;
89     pcibus_t val;
90 
91     tmp = (pcibus_t)pci_get_word(d->config + base);
92     val = (tmp & PCI_PREF_RANGE_MASK) << 16;
93     if (tmp & PCI_PREF_RANGE_TYPE_64) {
94         val |= (pcibus_t)pci_get_long(d->config + upper) << 32;
95     }
96     return val;
97 }
98 
99 /* accessor function to get bridge filtering base address */
100 pcibus_t pci_bridge_get_base(const PCIDevice *bridge, uint8_t type)
101 {
102     pcibus_t base;
103     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
104         base = pci_config_get_io_base(bridge,
105                                       PCI_IO_BASE, PCI_IO_BASE_UPPER16);
106     } else {
107         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
108             base = pci_config_get_pref_base(
109                 bridge, PCI_PREF_MEMORY_BASE, PCI_PREF_BASE_UPPER32);
110         } else {
111             base = pci_config_get_memory_base(bridge, PCI_MEMORY_BASE);
112         }
113     }
114 
115     return base;
116 }
117 
118 /* accessor funciton to get bridge filtering limit */
119 pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type)
120 {
121     pcibus_t limit;
122     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
123         limit = pci_config_get_io_base(bridge,
124                                       PCI_IO_LIMIT, PCI_IO_LIMIT_UPPER16);
125         limit |= 0xfff;         /* PCI bridge spec 3.2.5.6. */
126     } else {
127         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
128             limit = pci_config_get_pref_base(
129                 bridge, PCI_PREF_MEMORY_LIMIT, PCI_PREF_LIMIT_UPPER32);
130         } else {
131             limit = pci_config_get_memory_base(bridge, PCI_MEMORY_LIMIT);
132         }
133         limit |= 0xfffff;       /* PCI bridge spec 3.2.5.{1, 8}. */
134     }
135     return limit;
136 }
137 
138 static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
139                                   uint8_t type, const char *name,
140                                   MemoryRegion *space,
141                                   MemoryRegion *parent_space,
142                                   bool enabled)
143 {
144     pcibus_t base = pci_bridge_get_base(&bridge->dev, type);
145     pcibus_t limit = pci_bridge_get_limit(&bridge->dev, type);
146     /* TODO: this doesn't handle base = 0 limit = 2^64 - 1 correctly.
147      * Apparently no way to do this with existing memory APIs. */
148     pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
149 
150     memory_region_init_alias(alias, name, space, base, size);
151     memory_region_add_subregion_overlap(parent_space, base, alias, 1);
152 }
153 
154 static PCIBridgeWindows *pci_bridge_region_init(PCIBridge *br)
155 {
156     PCIBus *parent = br->dev.bus;
157     PCIBridgeWindows *w = g_new(PCIBridgeWindows, 1);
158     uint16_t cmd = pci_get_word(br->dev.config + PCI_COMMAND);
159 
160     pci_bridge_init_alias(br, &w->alias_pref_mem,
161                           PCI_BASE_ADDRESS_MEM_PREFETCH,
162                           "pci_bridge_pref_mem",
163                           &br->address_space_mem,
164                           parent->address_space_mem,
165                           cmd & PCI_COMMAND_MEMORY);
166     pci_bridge_init_alias(br, &w->alias_mem,
167                           PCI_BASE_ADDRESS_SPACE_MEMORY,
168                           "pci_bridge_mem",
169                           &br->address_space_mem,
170                           parent->address_space_mem,
171                           cmd & PCI_COMMAND_MEMORY);
172     pci_bridge_init_alias(br, &w->alias_io,
173                           PCI_BASE_ADDRESS_SPACE_IO,
174                           "pci_bridge_io",
175                           &br->address_space_io,
176                           parent->address_space_io,
177                           cmd & PCI_COMMAND_IO);
178    /* TODO: optinal VGA and VGA palette snooping support. */
179 
180     return w;
181 }
182 
183 static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
184 {
185     PCIBus *parent = br->dev.bus;
186 
187     memory_region_del_subregion(parent->address_space_io, &w->alias_io);
188     memory_region_del_subregion(parent->address_space_mem, &w->alias_mem);
189     memory_region_del_subregion(parent->address_space_mem, &w->alias_pref_mem);
190 }
191 
192 static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
193 {
194     memory_region_destroy(&w->alias_io);
195     memory_region_destroy(&w->alias_mem);
196     memory_region_destroy(&w->alias_pref_mem);
197     g_free(w);
198 }
199 
200 static void pci_bridge_update_mappings(PCIBridge *br)
201 {
202     PCIBridgeWindows *w = br->windows;
203 
204     /* Make updates atomic to: handle the case of one VCPU updating the bridge
205      * while another accesses an unaffected region. */
206     memory_region_transaction_begin();
207     pci_bridge_region_del(br, br->windows);
208     br->windows = pci_bridge_region_init(br);
209     memory_region_transaction_commit();
210     pci_bridge_region_cleanup(br, w);
211 }
212 
213 /* default write_config function for PCI-to-PCI bridge */
214 void pci_bridge_write_config(PCIDevice *d,
215                              uint32_t address, uint32_t val, int len)
216 {
217     PCIBridge *s = container_of(d, PCIBridge, dev);
218     uint16_t oldctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
219     uint16_t newctl;
220 
221     pci_default_write_config(d, address, val, len);
222 
223     if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
224 
225         /* io base/limit */
226         ranges_overlap(address, len, PCI_IO_BASE, 2) ||
227 
228         /* memory base/limit, prefetchable base/limit and
229            io base/limit upper 16 */
230         ranges_overlap(address, len, PCI_MEMORY_BASE, 20)) {
231         pci_bridge_update_mappings(s);
232     }
233 
234     newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
235     if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
236         /* Trigger hot reset on 0->1 transition. */
237         pci_bus_reset(&s->sec_bus);
238     }
239 }
240 
241 void pci_bridge_disable_base_limit(PCIDevice *dev)
242 {
243     uint8_t *conf = dev->config;
244 
245     pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
246                                PCI_IO_RANGE_MASK & 0xff);
247     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
248                                  PCI_IO_RANGE_MASK & 0xff);
249     pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
250                                PCI_MEMORY_RANGE_MASK & 0xffff);
251     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
252                                  PCI_MEMORY_RANGE_MASK & 0xffff);
253     pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
254                                PCI_PREF_RANGE_MASK & 0xffff);
255     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
256                                  PCI_PREF_RANGE_MASK & 0xffff);
257     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
258     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
259 }
260 
261 /* reset bridge specific configuration registers */
262 void pci_bridge_reset(DeviceState *qdev)
263 {
264     PCIDevice *dev = PCI_DEVICE(qdev);
265     uint8_t *conf = dev->config;
266 
267     conf[PCI_PRIMARY_BUS] = 0;
268     conf[PCI_SECONDARY_BUS] = 0;
269     conf[PCI_SUBORDINATE_BUS] = 0;
270     conf[PCI_SEC_LATENCY_TIMER] = 0;
271 
272     /*
273      * the default values for base/limit registers aren't specified
274      * in the PCI-to-PCI-bridge spec. So we don't thouch them here.
275      * Each implementation can override it.
276      * typical implementation does
277      * zero base/limit registers or
278      * disable forwarding: pci_bridge_disable_base_limit()
279      * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
280      * after this function.
281      */
282     pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
283                                  PCI_IO_RANGE_MASK & 0xff);
284     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
285                                  PCI_IO_RANGE_MASK & 0xff);
286     pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
287                                  PCI_MEMORY_RANGE_MASK & 0xffff);
288     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
289                                  PCI_MEMORY_RANGE_MASK & 0xffff);
290     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
291                                  PCI_PREF_RANGE_MASK & 0xffff);
292     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
293                                  PCI_PREF_RANGE_MASK & 0xffff);
294     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
295     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
296 
297     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
298 }
299 
300 /* default qdev initialization function for PCI-to-PCI bridge */
301 int pci_bridge_initfn(PCIDevice *dev)
302 {
303     PCIBus *parent = dev->bus;
304     PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
305     PCIBus *sec_bus = &br->sec_bus;
306 
307     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
308                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
309     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
310     dev->config[PCI_HEADER_TYPE] =
311         (dev->config[PCI_HEADER_TYPE] & PCI_HEADER_TYPE_MULTI_FUNCTION) |
312         PCI_HEADER_TYPE_BRIDGE;
313     pci_set_word(dev->config + PCI_SEC_STATUS,
314                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
315 
316     /*
317      * If we don't specify the name, the bus will be addressed as <id>.0, where
318      * id is the device id.
319      * Since PCI Bridge devices have a single bus each, we don't need the index:
320      * let users address the bus using the device name.
321      */
322     if (!br->bus_name && dev->qdev.id && *dev->qdev.id) {
323 	    br->bus_name = dev->qdev.id;
324     }
325 
326     qbus_create_inplace(&sec_bus->qbus, TYPE_PCI_BUS, &dev->qdev,
327                         br->bus_name);
328     sec_bus->parent_dev = dev;
329     sec_bus->map_irq = br->map_irq;
330     sec_bus->address_space_mem = &br->address_space_mem;
331     memory_region_init(&br->address_space_mem, "pci_bridge_pci", INT64_MAX);
332     sec_bus->address_space_io = &br->address_space_io;
333     memory_region_init(&br->address_space_io, "pci_bridge_io", 65536);
334     br->windows = pci_bridge_region_init(br);
335     QLIST_INIT(&sec_bus->child);
336     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
337     return 0;
338 }
339 
340 /* default qdev clean up function for PCI-to-PCI bridge */
341 void pci_bridge_exitfn(PCIDevice *pci_dev)
342 {
343     PCIBridge *s = DO_UPCAST(PCIBridge, dev, pci_dev);
344     assert(QLIST_EMPTY(&s->sec_bus.child));
345     QLIST_REMOVE(&s->sec_bus, sibling);
346     pci_bridge_region_del(s, s->windows);
347     pci_bridge_region_cleanup(s, s->windows);
348     memory_region_destroy(&s->address_space_mem);
349     memory_region_destroy(&s->address_space_io);
350     /* qbus_free() is called automatically by qdev_free() */
351 }
352 
353 /*
354  * before qdev initialization(qdev_init()), this function sets bus_name and
355  * map_irq callback which are necessry for pci_bridge_initfn() to
356  * initialize bus.
357  */
358 void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
359                         pci_map_irq_fn map_irq)
360 {
361     br->map_irq = map_irq;
362     br->bus_name = bus_name;
363 }
364