xref: /openbmc/qemu/hw/pci/pci_bridge.c (revision 1fd6bb44)
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 void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
155                                         MemoryRegion *alias_vga)
156 {
157     uint16_t brctl = pci_get_word(br->dev.config + PCI_BRIDGE_CONTROL);
158 
159     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO],
160                              "pci_bridge_vga_io_lo", &br->address_space_io,
161                              QEMU_PCI_VGA_IO_LO_BASE, QEMU_PCI_VGA_IO_LO_SIZE);
162     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI],
163                              "pci_bridge_vga_io_hi", &br->address_space_io,
164                              QEMU_PCI_VGA_IO_HI_BASE, QEMU_PCI_VGA_IO_HI_SIZE);
165     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM],
166                              "pci_bridge_vga_mem", &br->address_space_mem,
167                              QEMU_PCI_VGA_MEM_BASE, QEMU_PCI_VGA_MEM_SIZE);
168 
169     if (brctl & PCI_BRIDGE_CTL_VGA) {
170         pci_register_vga(&br->dev, &alias_vga[QEMU_PCI_VGA_MEM],
171                          &alias_vga[QEMU_PCI_VGA_IO_LO],
172                          &alias_vga[QEMU_PCI_VGA_IO_HI]);
173     }
174 }
175 
176 static PCIBridgeWindows *pci_bridge_region_init(PCIBridge *br)
177 {
178     PCIBus *parent = br->dev.bus;
179     PCIBridgeWindows *w = g_new(PCIBridgeWindows, 1);
180     uint16_t cmd = pci_get_word(br->dev.config + PCI_COMMAND);
181 
182     pci_bridge_init_alias(br, &w->alias_pref_mem,
183                           PCI_BASE_ADDRESS_MEM_PREFETCH,
184                           "pci_bridge_pref_mem",
185                           &br->address_space_mem,
186                           parent->address_space_mem,
187                           cmd & PCI_COMMAND_MEMORY);
188     pci_bridge_init_alias(br, &w->alias_mem,
189                           PCI_BASE_ADDRESS_SPACE_MEMORY,
190                           "pci_bridge_mem",
191                           &br->address_space_mem,
192                           parent->address_space_mem,
193                           cmd & PCI_COMMAND_MEMORY);
194     pci_bridge_init_alias(br, &w->alias_io,
195                           PCI_BASE_ADDRESS_SPACE_IO,
196                           "pci_bridge_io",
197                           &br->address_space_io,
198                           parent->address_space_io,
199                           cmd & PCI_COMMAND_IO);
200 
201     pci_bridge_init_vga_aliases(br, parent, w->alias_vga);
202 
203     return w;
204 }
205 
206 static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
207 {
208     PCIBus *parent = br->dev.bus;
209 
210     memory_region_del_subregion(parent->address_space_io, &w->alias_io);
211     memory_region_del_subregion(parent->address_space_mem, &w->alias_mem);
212     memory_region_del_subregion(parent->address_space_mem, &w->alias_pref_mem);
213     pci_unregister_vga(&br->dev);
214 }
215 
216 static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
217 {
218     memory_region_destroy(&w->alias_io);
219     memory_region_destroy(&w->alias_mem);
220     memory_region_destroy(&w->alias_pref_mem);
221     memory_region_destroy(&w->alias_vga[QEMU_PCI_VGA_IO_LO]);
222     memory_region_destroy(&w->alias_vga[QEMU_PCI_VGA_IO_HI]);
223     memory_region_destroy(&w->alias_vga[QEMU_PCI_VGA_MEM]);
224     g_free(w);
225 }
226 
227 static void pci_bridge_update_mappings(PCIBridge *br)
228 {
229     PCIBridgeWindows *w = br->windows;
230 
231     /* Make updates atomic to: handle the case of one VCPU updating the bridge
232      * while another accesses an unaffected region. */
233     memory_region_transaction_begin();
234     pci_bridge_region_del(br, br->windows);
235     br->windows = pci_bridge_region_init(br);
236     memory_region_transaction_commit();
237     pci_bridge_region_cleanup(br, w);
238 }
239 
240 /* default write_config function for PCI-to-PCI bridge */
241 void pci_bridge_write_config(PCIDevice *d,
242                              uint32_t address, uint32_t val, int len)
243 {
244     PCIBridge *s = container_of(d, PCIBridge, dev);
245     uint16_t oldctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
246     uint16_t newctl;
247 
248     pci_default_write_config(d, address, val, len);
249 
250     if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
251 
252         /* io base/limit */
253         ranges_overlap(address, len, PCI_IO_BASE, 2) ||
254 
255         /* memory base/limit, prefetchable base/limit and
256            io base/limit upper 16 */
257         ranges_overlap(address, len, PCI_MEMORY_BASE, 20) ||
258 
259         /* vga enable */
260         ranges_overlap(address, len, PCI_BRIDGE_CONTROL, 2)) {
261         pci_bridge_update_mappings(s);
262     }
263 
264     newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
265     if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
266         /* Trigger hot reset on 0->1 transition. */
267         pci_bus_reset(&s->sec_bus);
268     }
269 }
270 
271 void pci_bridge_disable_base_limit(PCIDevice *dev)
272 {
273     uint8_t *conf = dev->config;
274 
275     pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
276                                PCI_IO_RANGE_MASK & 0xff);
277     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
278                                  PCI_IO_RANGE_MASK & 0xff);
279     pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
280                                PCI_MEMORY_RANGE_MASK & 0xffff);
281     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
282                                  PCI_MEMORY_RANGE_MASK & 0xffff);
283     pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
284                                PCI_PREF_RANGE_MASK & 0xffff);
285     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
286                                  PCI_PREF_RANGE_MASK & 0xffff);
287     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
288     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
289 }
290 
291 /* reset bridge specific configuration registers */
292 void pci_bridge_reset(DeviceState *qdev)
293 {
294     PCIDevice *dev = PCI_DEVICE(qdev);
295     uint8_t *conf = dev->config;
296 
297     conf[PCI_PRIMARY_BUS] = 0;
298     conf[PCI_SECONDARY_BUS] = 0;
299     conf[PCI_SUBORDINATE_BUS] = 0;
300     conf[PCI_SEC_LATENCY_TIMER] = 0;
301 
302     /*
303      * the default values for base/limit registers aren't specified
304      * in the PCI-to-PCI-bridge spec. So we don't thouch them here.
305      * Each implementation can override it.
306      * typical implementation does
307      * zero base/limit registers or
308      * disable forwarding: pci_bridge_disable_base_limit()
309      * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
310      * after this function.
311      */
312     pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
313                                  PCI_IO_RANGE_MASK & 0xff);
314     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
315                                  PCI_IO_RANGE_MASK & 0xff);
316     pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
317                                  PCI_MEMORY_RANGE_MASK & 0xffff);
318     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
319                                  PCI_MEMORY_RANGE_MASK & 0xffff);
320     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
321                                  PCI_PREF_RANGE_MASK & 0xffff);
322     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
323                                  PCI_PREF_RANGE_MASK & 0xffff);
324     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
325     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
326 
327     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
328 }
329 
330 /* default qdev initialization function for PCI-to-PCI bridge */
331 int pci_bridge_initfn(PCIDevice *dev, const char *typename)
332 {
333     PCIBus *parent = dev->bus;
334     PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
335     PCIBus *sec_bus = &br->sec_bus;
336 
337     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
338                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
339 
340     /*
341      * TODO: We implement VGA Enable in the Bridge Control Register
342      * therefore per the PCI to PCI bridge spec we must also implement
343      * VGA Palette Snooping.  When done, set this bit writable:
344      *
345      * pci_word_test_and_set_mask(dev->wmask + PCI_COMMAND,
346      *                            PCI_COMMAND_VGA_PALETTE);
347      */
348 
349     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
350     dev->config[PCI_HEADER_TYPE] =
351         (dev->config[PCI_HEADER_TYPE] & PCI_HEADER_TYPE_MULTI_FUNCTION) |
352         PCI_HEADER_TYPE_BRIDGE;
353     pci_set_word(dev->config + PCI_SEC_STATUS,
354                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
355 
356     /*
357      * If we don't specify the name, the bus will be addressed as <id>.0, where
358      * id is the device id.
359      * Since PCI Bridge devices have a single bus each, we don't need the index:
360      * let users address the bus using the device name.
361      */
362     if (!br->bus_name && dev->qdev.id && *dev->qdev.id) {
363 	    br->bus_name = dev->qdev.id;
364     }
365 
366     qbus_create_inplace(&sec_bus->qbus, typename, &dev->qdev, br->bus_name);
367     sec_bus->parent_dev = dev;
368     sec_bus->map_irq = br->map_irq ? br->map_irq : pci_swizzle_map_irq_fn;
369     sec_bus->address_space_mem = &br->address_space_mem;
370     memory_region_init(&br->address_space_mem, "pci_bridge_pci", INT64_MAX);
371     sec_bus->address_space_io = &br->address_space_io;
372     memory_region_init(&br->address_space_io, "pci_bridge_io", 65536);
373     br->windows = pci_bridge_region_init(br);
374     QLIST_INIT(&sec_bus->child);
375     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
376     return 0;
377 }
378 
379 /* default qdev clean up function for PCI-to-PCI bridge */
380 void pci_bridge_exitfn(PCIDevice *pci_dev)
381 {
382     PCIBridge *s = DO_UPCAST(PCIBridge, dev, pci_dev);
383     assert(QLIST_EMPTY(&s->sec_bus.child));
384     QLIST_REMOVE(&s->sec_bus, sibling);
385     pci_bridge_region_del(s, s->windows);
386     pci_bridge_region_cleanup(s, s->windows);
387     memory_region_destroy(&s->address_space_mem);
388     memory_region_destroy(&s->address_space_io);
389     /* qbus_free() is called automatically by qdev_free() */
390 }
391 
392 /*
393  * before qdev initialization(qdev_init()), this function sets bus_name and
394  * map_irq callback which are necessry for pci_bridge_initfn() to
395  * initialize bus.
396  */
397 void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
398                         pci_map_irq_fn map_irq)
399 {
400     br->map_irq = map_irq;
401     br->bus_name = bus_name;
402 }
403