xref: /openbmc/qemu/hw/pci/pci_bridge.c (revision fcf5ef2a)
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 "qemu/osdep.h"
33 #include "hw/pci/pci_bridge.h"
34 #include "hw/pci/pci_bus.h"
35 #include "qemu/range.h"
36 
37 /* PCI bridge subsystem vendor ID helper functions */
38 #define PCI_SSVID_SIZEOF        8
39 #define PCI_SSVID_SVID          4
40 #define PCI_SSVID_SSID          6
41 
42 int pci_bridge_ssvid_init(PCIDevice *dev, uint8_t offset,
43                           uint16_t svid, uint16_t ssid)
44 {
45     int pos;
46     pos = pci_add_capability(dev, PCI_CAP_ID_SSVID, offset, PCI_SSVID_SIZEOF);
47     if (pos < 0) {
48         return pos;
49     }
50 
51     pci_set_word(dev->config + pos + PCI_SSVID_SVID, svid);
52     pci_set_word(dev->config + pos + PCI_SSVID_SSID, ssid);
53     return pos;
54 }
55 
56 /* Accessor function to get parent bridge device from pci bus. */
57 PCIDevice *pci_bridge_get_device(PCIBus *bus)
58 {
59     return bus->parent_dev;
60 }
61 
62 /* Accessor function to get secondary bus from pci-to-pci bridge device */
63 PCIBus *pci_bridge_get_sec_bus(PCIBridge *br)
64 {
65     return &br->sec_bus;
66 }
67 
68 static uint32_t pci_config_get_io_base(const PCIDevice *d,
69                                        uint32_t base, uint32_t base_upper16)
70 {
71     uint32_t val;
72 
73     val = ((uint32_t)d->config[base] & PCI_IO_RANGE_MASK) << 8;
74     if (d->config[base] & PCI_IO_RANGE_TYPE_32) {
75         val |= (uint32_t)pci_get_word(d->config + base_upper16) << 16;
76     }
77     return val;
78 }
79 
80 static pcibus_t pci_config_get_memory_base(const PCIDevice *d, uint32_t base)
81 {
82     return ((pcibus_t)pci_get_word(d->config + base) & PCI_MEMORY_RANGE_MASK)
83         << 16;
84 }
85 
86 static pcibus_t pci_config_get_pref_base(const PCIDevice *d,
87                                          uint32_t base, uint32_t upper)
88 {
89     pcibus_t tmp;
90     pcibus_t val;
91 
92     tmp = (pcibus_t)pci_get_word(d->config + base);
93     val = (tmp & PCI_PREF_RANGE_MASK) << 16;
94     if (tmp & PCI_PREF_RANGE_TYPE_64) {
95         val |= (pcibus_t)pci_get_long(d->config + upper) << 32;
96     }
97     return val;
98 }
99 
100 /* accessor function to get bridge filtering base address */
101 pcibus_t pci_bridge_get_base(const PCIDevice *bridge, uint8_t type)
102 {
103     pcibus_t base;
104     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
105         base = pci_config_get_io_base(bridge,
106                                       PCI_IO_BASE, PCI_IO_BASE_UPPER16);
107     } else {
108         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
109             base = pci_config_get_pref_base(
110                 bridge, PCI_PREF_MEMORY_BASE, PCI_PREF_BASE_UPPER32);
111         } else {
112             base = pci_config_get_memory_base(bridge, PCI_MEMORY_BASE);
113         }
114     }
115 
116     return base;
117 }
118 
119 /* accessor function to get bridge filtering limit */
120 pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type)
121 {
122     pcibus_t limit;
123     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
124         limit = pci_config_get_io_base(bridge,
125                                       PCI_IO_LIMIT, PCI_IO_LIMIT_UPPER16);
126         limit |= 0xfff;         /* PCI bridge spec 3.2.5.6. */
127     } else {
128         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
129             limit = pci_config_get_pref_base(
130                 bridge, PCI_PREF_MEMORY_LIMIT, PCI_PREF_LIMIT_UPPER32);
131         } else {
132             limit = pci_config_get_memory_base(bridge, PCI_MEMORY_LIMIT);
133         }
134         limit |= 0xfffff;       /* PCI bridge spec 3.2.5.{1, 8}. */
135     }
136     return limit;
137 }
138 
139 static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
140                                   uint8_t type, const char *name,
141                                   MemoryRegion *space,
142                                   MemoryRegion *parent_space,
143                                   bool enabled)
144 {
145     PCIDevice *bridge_dev = PCI_DEVICE(bridge);
146     pcibus_t base = pci_bridge_get_base(bridge_dev, type);
147     pcibus_t limit = pci_bridge_get_limit(bridge_dev, type);
148     /* TODO: this doesn't handle base = 0 limit = 2^64 - 1 correctly.
149      * Apparently no way to do this with existing memory APIs. */
150     pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
151 
152     memory_region_init_alias(alias, OBJECT(bridge), name, space, base, size);
153     memory_region_add_subregion_overlap(parent_space, base, alias, 1);
154 }
155 
156 static void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
157                                         MemoryRegion *alias_vga)
158 {
159     PCIDevice *pd = PCI_DEVICE(br);
160     uint16_t brctl = pci_get_word(pd->config + PCI_BRIDGE_CONTROL);
161 
162     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO], OBJECT(br),
163                              "pci_bridge_vga_io_lo", &br->address_space_io,
164                              QEMU_PCI_VGA_IO_LO_BASE, QEMU_PCI_VGA_IO_LO_SIZE);
165     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI], OBJECT(br),
166                              "pci_bridge_vga_io_hi", &br->address_space_io,
167                              QEMU_PCI_VGA_IO_HI_BASE, QEMU_PCI_VGA_IO_HI_SIZE);
168     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM], OBJECT(br),
169                              "pci_bridge_vga_mem", &br->address_space_mem,
170                              QEMU_PCI_VGA_MEM_BASE, QEMU_PCI_VGA_MEM_SIZE);
171 
172     if (brctl & PCI_BRIDGE_CTL_VGA) {
173         pci_register_vga(pd, &alias_vga[QEMU_PCI_VGA_MEM],
174                          &alias_vga[QEMU_PCI_VGA_IO_LO],
175                          &alias_vga[QEMU_PCI_VGA_IO_HI]);
176     }
177 }
178 
179 static PCIBridgeWindows *pci_bridge_region_init(PCIBridge *br)
180 {
181     PCIDevice *pd = PCI_DEVICE(br);
182     PCIBus *parent = pd->bus;
183     PCIBridgeWindows *w = g_new(PCIBridgeWindows, 1);
184     uint16_t cmd = pci_get_word(pd->config + PCI_COMMAND);
185 
186     pci_bridge_init_alias(br, &w->alias_pref_mem,
187                           PCI_BASE_ADDRESS_MEM_PREFETCH,
188                           "pci_bridge_pref_mem",
189                           &br->address_space_mem,
190                           parent->address_space_mem,
191                           cmd & PCI_COMMAND_MEMORY);
192     pci_bridge_init_alias(br, &w->alias_mem,
193                           PCI_BASE_ADDRESS_SPACE_MEMORY,
194                           "pci_bridge_mem",
195                           &br->address_space_mem,
196                           parent->address_space_mem,
197                           cmd & PCI_COMMAND_MEMORY);
198     pci_bridge_init_alias(br, &w->alias_io,
199                           PCI_BASE_ADDRESS_SPACE_IO,
200                           "pci_bridge_io",
201                           &br->address_space_io,
202                           parent->address_space_io,
203                           cmd & PCI_COMMAND_IO);
204 
205     pci_bridge_init_vga_aliases(br, parent, w->alias_vga);
206 
207     return w;
208 }
209 
210 static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
211 {
212     PCIDevice *pd = PCI_DEVICE(br);
213     PCIBus *parent = pd->bus;
214 
215     memory_region_del_subregion(parent->address_space_io, &w->alias_io);
216     memory_region_del_subregion(parent->address_space_mem, &w->alias_mem);
217     memory_region_del_subregion(parent->address_space_mem, &w->alias_pref_mem);
218     pci_unregister_vga(pd);
219 }
220 
221 static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
222 {
223     object_unparent(OBJECT(&w->alias_io));
224     object_unparent(OBJECT(&w->alias_mem));
225     object_unparent(OBJECT(&w->alias_pref_mem));
226     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_IO_LO]));
227     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_IO_HI]));
228     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_MEM]));
229     g_free(w);
230 }
231 
232 void pci_bridge_update_mappings(PCIBridge *br)
233 {
234     PCIBridgeWindows *w = br->windows;
235 
236     /* Make updates atomic to: handle the case of one VCPU updating the bridge
237      * while another accesses an unaffected region. */
238     memory_region_transaction_begin();
239     pci_bridge_region_del(br, br->windows);
240     br->windows = pci_bridge_region_init(br);
241     memory_region_transaction_commit();
242     pci_bridge_region_cleanup(br, w);
243 }
244 
245 /* default write_config function for PCI-to-PCI bridge */
246 void pci_bridge_write_config(PCIDevice *d,
247                              uint32_t address, uint32_t val, int len)
248 {
249     PCIBridge *s = PCI_BRIDGE(d);
250     uint16_t oldctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
251     uint16_t newctl;
252 
253     pci_default_write_config(d, address, val, len);
254 
255     if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
256 
257         /* io base/limit */
258         ranges_overlap(address, len, PCI_IO_BASE, 2) ||
259 
260         /* memory base/limit, prefetchable base/limit and
261            io base/limit upper 16 */
262         ranges_overlap(address, len, PCI_MEMORY_BASE, 20) ||
263 
264         /* vga enable */
265         ranges_overlap(address, len, PCI_BRIDGE_CONTROL, 2)) {
266         pci_bridge_update_mappings(s);
267     }
268 
269     newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
270     if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
271         /* Trigger hot reset on 0->1 transition. */
272         qbus_reset_all(&s->sec_bus.qbus);
273     }
274 }
275 
276 void pci_bridge_disable_base_limit(PCIDevice *dev)
277 {
278     uint8_t *conf = dev->config;
279 
280     pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
281                                PCI_IO_RANGE_MASK & 0xff);
282     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
283                                  PCI_IO_RANGE_MASK & 0xff);
284     pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
285                                PCI_MEMORY_RANGE_MASK & 0xffff);
286     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
287                                  PCI_MEMORY_RANGE_MASK & 0xffff);
288     pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
289                                PCI_PREF_RANGE_MASK & 0xffff);
290     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
291                                  PCI_PREF_RANGE_MASK & 0xffff);
292     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
293     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
294 }
295 
296 /* reset bridge specific configuration registers */
297 void pci_bridge_reset(DeviceState *qdev)
298 {
299     PCIDevice *dev = PCI_DEVICE(qdev);
300     uint8_t *conf = dev->config;
301 
302     conf[PCI_PRIMARY_BUS] = 0;
303     conf[PCI_SECONDARY_BUS] = 0;
304     conf[PCI_SUBORDINATE_BUS] = 0;
305     conf[PCI_SEC_LATENCY_TIMER] = 0;
306 
307     /*
308      * the default values for base/limit registers aren't specified
309      * in the PCI-to-PCI-bridge spec. So we don't thouch them here.
310      * Each implementation can override it.
311      * typical implementation does
312      * zero base/limit registers or
313      * disable forwarding: pci_bridge_disable_base_limit()
314      * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
315      * after this function.
316      */
317     pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
318                                  PCI_IO_RANGE_MASK & 0xff);
319     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
320                                  PCI_IO_RANGE_MASK & 0xff);
321     pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
322                                  PCI_MEMORY_RANGE_MASK & 0xffff);
323     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
324                                  PCI_MEMORY_RANGE_MASK & 0xffff);
325     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
326                                  PCI_PREF_RANGE_MASK & 0xffff);
327     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
328                                  PCI_PREF_RANGE_MASK & 0xffff);
329     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
330     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
331 
332     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
333 }
334 
335 /* default qdev initialization function for PCI-to-PCI bridge */
336 void pci_bridge_initfn(PCIDevice *dev, const char *typename)
337 {
338     PCIBus *parent = dev->bus;
339     PCIBridge *br = PCI_BRIDGE(dev);
340     PCIBus *sec_bus = &br->sec_bus;
341 
342     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
343                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
344 
345     /*
346      * TODO: We implement VGA Enable in the Bridge Control Register
347      * therefore per the PCI to PCI bridge spec we must also implement
348      * VGA Palette Snooping.  When done, set this bit writable:
349      *
350      * pci_word_test_and_set_mask(dev->wmask + PCI_COMMAND,
351      *                            PCI_COMMAND_VGA_PALETTE);
352      */
353 
354     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
355     dev->config[PCI_HEADER_TYPE] =
356         (dev->config[PCI_HEADER_TYPE] & PCI_HEADER_TYPE_MULTI_FUNCTION) |
357         PCI_HEADER_TYPE_BRIDGE;
358     pci_set_word(dev->config + PCI_SEC_STATUS,
359                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
360 
361     /*
362      * If we don't specify the name, the bus will be addressed as <id>.0, where
363      * id is the device id.
364      * Since PCI Bridge devices have a single bus each, we don't need the index:
365      * let users address the bus using the device name.
366      */
367     if (!br->bus_name && dev->qdev.id && *dev->qdev.id) {
368 	    br->bus_name = dev->qdev.id;
369     }
370 
371     qbus_create_inplace(sec_bus, sizeof(br->sec_bus), typename, DEVICE(dev),
372                         br->bus_name);
373     sec_bus->parent_dev = dev;
374     sec_bus->map_irq = br->map_irq ? br->map_irq : pci_swizzle_map_irq_fn;
375     sec_bus->address_space_mem = &br->address_space_mem;
376     memory_region_init(&br->address_space_mem, OBJECT(br), "pci_bridge_pci", UINT64_MAX);
377     sec_bus->address_space_io = &br->address_space_io;
378     memory_region_init(&br->address_space_io, OBJECT(br), "pci_bridge_io", 65536);
379     br->windows = pci_bridge_region_init(br);
380     QLIST_INIT(&sec_bus->child);
381     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
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     /* object_unparent() is called automatically during device deletion */
393 }
394 
395 /*
396  * before qdev initialization(qdev_init()), this function sets bus_name and
397  * map_irq callback which are necessry for pci_bridge_initfn() to
398  * initialize bus.
399  */
400 void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
401                         pci_map_irq_fn map_irq)
402 {
403     br->map_irq = map_irq;
404     br->bus_name = bus_name;
405 }
406 
407 static const TypeInfo pci_bridge_type_info = {
408     .name = TYPE_PCI_BRIDGE,
409     .parent = TYPE_PCI_DEVICE,
410     .instance_size = sizeof(PCIBridge),
411     .abstract = true,
412 };
413 
414 static void pci_bridge_register_types(void)
415 {
416     type_register_static(&pci_bridge_type_info);
417 }
418 
419 type_init(pci_bridge_register_types)
420