xref: /openbmc/qemu/hw/pci/pci_bridge.c (revision 14a650ec)
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     PCIDevice *bridge_dev = PCI_DEVICE(bridge);
145     pcibus_t base = pci_bridge_get_base(bridge_dev, type);
146     pcibus_t limit = pci_bridge_get_limit(bridge_dev, type);
147     /* TODO: this doesn't handle base = 0 limit = 2^64 - 1 correctly.
148      * Apparently no way to do this with existing memory APIs. */
149     pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
150 
151     memory_region_init_alias(alias, OBJECT(bridge), name, space, base, size);
152     memory_region_add_subregion_overlap(parent_space, base, alias, 1);
153 }
154 
155 static void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
156                                         MemoryRegion *alias_vga)
157 {
158     PCIDevice *pd = PCI_DEVICE(br);
159     uint16_t brctl = pci_get_word(pd->config + PCI_BRIDGE_CONTROL);
160 
161     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO], OBJECT(br),
162                              "pci_bridge_vga_io_lo", &br->address_space_io,
163                              QEMU_PCI_VGA_IO_LO_BASE, QEMU_PCI_VGA_IO_LO_SIZE);
164     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI], OBJECT(br),
165                              "pci_bridge_vga_io_hi", &br->address_space_io,
166                              QEMU_PCI_VGA_IO_HI_BASE, QEMU_PCI_VGA_IO_HI_SIZE);
167     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM], OBJECT(br),
168                              "pci_bridge_vga_mem", &br->address_space_mem,
169                              QEMU_PCI_VGA_MEM_BASE, QEMU_PCI_VGA_MEM_SIZE);
170 
171     if (brctl & PCI_BRIDGE_CTL_VGA) {
172         pci_register_vga(pd, &alias_vga[QEMU_PCI_VGA_MEM],
173                          &alias_vga[QEMU_PCI_VGA_IO_LO],
174                          &alias_vga[QEMU_PCI_VGA_IO_HI]);
175     }
176 }
177 
178 static PCIBridgeWindows *pci_bridge_region_init(PCIBridge *br)
179 {
180     PCIDevice *pd = PCI_DEVICE(br);
181     PCIBus *parent = pd->bus;
182     PCIBridgeWindows *w = g_new(PCIBridgeWindows, 1);
183     uint16_t cmd = pci_get_word(pd->config + PCI_COMMAND);
184 
185     pci_bridge_init_alias(br, &w->alias_pref_mem,
186                           PCI_BASE_ADDRESS_MEM_PREFETCH,
187                           "pci_bridge_pref_mem",
188                           &br->address_space_mem,
189                           parent->address_space_mem,
190                           cmd & PCI_COMMAND_MEMORY);
191     pci_bridge_init_alias(br, &w->alias_mem,
192                           PCI_BASE_ADDRESS_SPACE_MEMORY,
193                           "pci_bridge_mem",
194                           &br->address_space_mem,
195                           parent->address_space_mem,
196                           cmd & PCI_COMMAND_MEMORY);
197     pci_bridge_init_alias(br, &w->alias_io,
198                           PCI_BASE_ADDRESS_SPACE_IO,
199                           "pci_bridge_io",
200                           &br->address_space_io,
201                           parent->address_space_io,
202                           cmd & PCI_COMMAND_IO);
203 
204     pci_bridge_init_vga_aliases(br, parent, w->alias_vga);
205 
206     return w;
207 }
208 
209 static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
210 {
211     PCIDevice *pd = PCI_DEVICE(br);
212     PCIBus *parent = pd->bus;
213 
214     memory_region_del_subregion(parent->address_space_io, &w->alias_io);
215     memory_region_del_subregion(parent->address_space_mem, &w->alias_mem);
216     memory_region_del_subregion(parent->address_space_mem, &w->alias_pref_mem);
217     pci_unregister_vga(pd);
218 }
219 
220 static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
221 {
222     memory_region_destroy(&w->alias_io);
223     memory_region_destroy(&w->alias_mem);
224     memory_region_destroy(&w->alias_pref_mem);
225     memory_region_destroy(&w->alias_vga[QEMU_PCI_VGA_IO_LO]);
226     memory_region_destroy(&w->alias_vga[QEMU_PCI_VGA_IO_HI]);
227     memory_region_destroy(&w->alias_vga[QEMU_PCI_VGA_MEM]);
228     g_free(w);
229 }
230 
231 void pci_bridge_update_mappings(PCIBridge *br)
232 {
233     PCIBridgeWindows *w = br->windows;
234 
235     /* Make updates atomic to: handle the case of one VCPU updating the bridge
236      * while another accesses an unaffected region. */
237     memory_region_transaction_begin();
238     pci_bridge_region_del(br, br->windows);
239     br->windows = pci_bridge_region_init(br);
240     memory_region_transaction_commit();
241     pci_bridge_region_cleanup(br, w);
242 }
243 
244 /* default write_config function for PCI-to-PCI bridge */
245 void pci_bridge_write_config(PCIDevice *d,
246                              uint32_t address, uint32_t val, int len)
247 {
248     PCIBridge *s = PCI_BRIDGE(d);
249     uint16_t oldctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
250     uint16_t newctl;
251 
252     pci_default_write_config(d, address, val, len);
253 
254     if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
255 
256         /* io base/limit */
257         ranges_overlap(address, len, PCI_IO_BASE, 2) ||
258 
259         /* memory base/limit, prefetchable base/limit and
260            io base/limit upper 16 */
261         ranges_overlap(address, len, PCI_MEMORY_BASE, 20) ||
262 
263         /* vga enable */
264         ranges_overlap(address, len, PCI_BRIDGE_CONTROL, 2)) {
265         pci_bridge_update_mappings(s);
266     }
267 
268     newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
269     if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
270         /* Trigger hot reset on 0->1 transition. */
271         pci_bus_reset(&s->sec_bus);
272     }
273 }
274 
275 void pci_bridge_disable_base_limit(PCIDevice *dev)
276 {
277     uint8_t *conf = dev->config;
278 
279     pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
280                                PCI_IO_RANGE_MASK & 0xff);
281     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
282                                  PCI_IO_RANGE_MASK & 0xff);
283     pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
284                                PCI_MEMORY_RANGE_MASK & 0xffff);
285     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
286                                  PCI_MEMORY_RANGE_MASK & 0xffff);
287     pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
288                                PCI_PREF_RANGE_MASK & 0xffff);
289     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
290                                  PCI_PREF_RANGE_MASK & 0xffff);
291     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
292     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
293 }
294 
295 /* reset bridge specific configuration registers */
296 void pci_bridge_reset(DeviceState *qdev)
297 {
298     PCIDevice *dev = PCI_DEVICE(qdev);
299     uint8_t *conf = dev->config;
300 
301     conf[PCI_PRIMARY_BUS] = 0;
302     conf[PCI_SECONDARY_BUS] = 0;
303     conf[PCI_SUBORDINATE_BUS] = 0;
304     conf[PCI_SEC_LATENCY_TIMER] = 0;
305 
306     /*
307      * the default values for base/limit registers aren't specified
308      * in the PCI-to-PCI-bridge spec. So we don't thouch them here.
309      * Each implementation can override it.
310      * typical implementation does
311      * zero base/limit registers or
312      * disable forwarding: pci_bridge_disable_base_limit()
313      * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
314      * after this function.
315      */
316     pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
317                                  PCI_IO_RANGE_MASK & 0xff);
318     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
319                                  PCI_IO_RANGE_MASK & 0xff);
320     pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
321                                  PCI_MEMORY_RANGE_MASK & 0xffff);
322     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
323                                  PCI_MEMORY_RANGE_MASK & 0xffff);
324     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
325                                  PCI_PREF_RANGE_MASK & 0xffff);
326     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
327                                  PCI_PREF_RANGE_MASK & 0xffff);
328     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
329     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
330 
331     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
332 }
333 
334 /* default qdev initialization function for PCI-to-PCI bridge */
335 int pci_bridge_initfn(PCIDevice *dev, const char *typename)
336 {
337     PCIBus *parent = dev->bus;
338     PCIBridge *br = PCI_BRIDGE(dev);
339     PCIBus *sec_bus = &br->sec_bus;
340 
341     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
342                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
343 
344     /*
345      * TODO: We implement VGA Enable in the Bridge Control Register
346      * therefore per the PCI to PCI bridge spec we must also implement
347      * VGA Palette Snooping.  When done, set this bit writable:
348      *
349      * pci_word_test_and_set_mask(dev->wmask + PCI_COMMAND,
350      *                            PCI_COMMAND_VGA_PALETTE);
351      */
352 
353     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
354     dev->config[PCI_HEADER_TYPE] =
355         (dev->config[PCI_HEADER_TYPE] & PCI_HEADER_TYPE_MULTI_FUNCTION) |
356         PCI_HEADER_TYPE_BRIDGE;
357     pci_set_word(dev->config + PCI_SEC_STATUS,
358                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
359 
360     /*
361      * If we don't specify the name, the bus will be addressed as <id>.0, where
362      * id is the device id.
363      * Since PCI Bridge devices have a single bus each, we don't need the index:
364      * let users address the bus using the device name.
365      */
366     if (!br->bus_name && dev->qdev.id && *dev->qdev.id) {
367 	    br->bus_name = dev->qdev.id;
368     }
369 
370     qbus_create_inplace(sec_bus, sizeof(br->sec_bus), typename, DEVICE(dev),
371                         br->bus_name);
372     sec_bus->parent_dev = dev;
373     sec_bus->map_irq = br->map_irq ? br->map_irq : pci_swizzle_map_irq_fn;
374     sec_bus->address_space_mem = &br->address_space_mem;
375     memory_region_init(&br->address_space_mem, OBJECT(br), "pci_bridge_pci", INT64_MAX);
376     sec_bus->address_space_io = &br->address_space_io;
377     memory_region_init(&br->address_space_io, OBJECT(br), "pci_bridge_io", 65536);
378     br->windows = pci_bridge_region_init(br);
379     QLIST_INIT(&sec_bus->child);
380     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
381     return 0;
382 }
383 
384 /* default qdev clean up function for PCI-to-PCI bridge */
385 void pci_bridge_exitfn(PCIDevice *pci_dev)
386 {
387     PCIBridge *s = PCI_BRIDGE(pci_dev);
388     assert(QLIST_EMPTY(&s->sec_bus.child));
389     QLIST_REMOVE(&s->sec_bus, sibling);
390     pci_bridge_region_del(s, s->windows);
391     pci_bridge_region_cleanup(s, s->windows);
392     memory_region_destroy(&s->address_space_mem);
393     memory_region_destroy(&s->address_space_io);
394     /* qbus_free() is called automatically during device deletion */
395 }
396 
397 /*
398  * before qdev initialization(qdev_init()), this function sets bus_name and
399  * map_irq callback which are necessry for pci_bridge_initfn() to
400  * initialize bus.
401  */
402 void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
403                         pci_map_irq_fn map_irq)
404 {
405     br->map_irq = map_irq;
406     br->bus_name = bus_name;
407 }
408 
409 static const TypeInfo pci_bridge_type_info = {
410     .name = TYPE_PCI_BRIDGE,
411     .parent = TYPE_PCI_DEVICE,
412     .instance_size = sizeof(PCIBridge),
413     .abstract = true,
414 };
415 
416 static void pci_bridge_register_types(void)
417 {
418     type_register_static(&pci_bridge_type_info);
419 }
420 
421 type_init(pci_bridge_register_types)
422