xref: /openbmc/qemu/hw/pci-host/versatile.c (revision a4d50b1d)
1 /*
2  * ARM Versatile/PB PCI host controller
3  *
4  * Copyright (c) 2006-2009 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the LGPL.
8  */
9 
10 #include "qemu/osdep.h"
11 #include "hw/sysbus.h"
12 #include "hw/pci/pci.h"
13 #include "hw/pci/pci_bus.h"
14 #include "hw/pci/pci_host.h"
15 #include "exec/address-spaces.h"
16 #include "qemu/log.h"
17 
18 /* Old and buggy versions of QEMU used the wrong mapping from
19  * PCI IRQs to system interrupt lines. Unfortunately the Linux
20  * kernel also had the corresponding bug in setting up interrupts
21  * (so older kernels work on QEMU and not on real hardware).
22  * We automatically detect these broken kernels and flip back
23  * to the broken irq mapping by spotting guest writes to the
24  * PCI_INTERRUPT_LINE register to see where the guest thinks
25  * interrupts are going to be routed. So we start in state
26  * ASSUME_OK on reset, and transition to either BROKEN or
27  * FORCE_OK at the first write to an INTERRUPT_LINE register for
28  * a slot where broken and correct interrupt mapping would differ.
29  * Once in either BROKEN or FORCE_OK we never transition again;
30  * this allows a newer kernel to use the INTERRUPT_LINE
31  * registers arbitrarily once it has indicated that it isn't
32  * broken in its init code somewhere.
33  *
34  * Unfortunately we have to cope with multiple different
35  * variants on the broken kernel behaviour:
36  *  phase I (before kernel commit 1bc39ac5d) kernels assume old
37  *   QEMU behaviour, so they use IRQ 27 for all slots
38  *  phase II (1bc39ac5d and later, but before e3e92a7be6) kernels
39  *   swizzle IRQs between slots, but do it wrongly, so they
40  *   work only for every fourth PCI card, and only if (like old
41  *   QEMU) the PCI host device is at slot 0 rather than where
42  *   the h/w actually puts it
43  *  phase III (e3e92a7be6 and later) kernels still swizzle IRQs between
44  *   slots wrongly, but add a fixed offset of 64 to everything
45  *   they write to PCI_INTERRUPT_LINE.
46  *
47  * We live in hope of a mythical phase IV kernel which might
48  * actually behave in ways that work on the hardware. Such a
49  * kernel should probably start off by writing some value neither
50  * 27 nor 91 to slot zero's PCI_INTERRUPT_LINE register to
51  * disable the autodetection. After that it can do what it likes.
52  *
53  * Slot % 4 | hw | I  | II | III
54  * -------------------------------
55  *   0      | 29 | 27 | 27 | 91
56  *   1      | 30 | 27 | 28 | 92
57  *   2      | 27 | 27 | 29 | 93
58  *   3      | 28 | 27 | 30 | 94
59  *
60  * Since our autodetection is not perfect we also provide a
61  * property so the user can make us start in BROKEN or FORCE_OK
62  * on reset if they know they have a bad or good kernel.
63  */
64 enum {
65     PCI_VPB_IRQMAP_ASSUME_OK,
66     PCI_VPB_IRQMAP_BROKEN,
67     PCI_VPB_IRQMAP_FORCE_OK,
68 };
69 
70 typedef struct {
71     PCIHostState parent_obj;
72 
73     qemu_irq irq[4];
74     MemoryRegion controlregs;
75     MemoryRegion mem_config;
76     MemoryRegion mem_config2;
77     /* Containers representing the PCI address spaces */
78     MemoryRegion pci_io_space;
79     MemoryRegion pci_mem_space;
80     /* Alias regions into PCI address spaces which we expose as sysbus regions.
81      * The offsets into pci_mem_space are controlled by the imap registers.
82      */
83     MemoryRegion pci_io_window;
84     MemoryRegion pci_mem_window[3];
85     PCIBus pci_bus;
86     PCIDevice pci_dev;
87 
88     /* Constant for life of device: */
89     int realview;
90     uint32_t mem_win_size[3];
91     uint8_t irq_mapping_prop;
92 
93     /* Variable state: */
94     uint32_t imap[3];
95     uint32_t smap[3];
96     uint32_t selfid;
97     uint32_t flags;
98     uint8_t irq_mapping;
99 } PCIVPBState;
100 
101 static void pci_vpb_update_window(PCIVPBState *s, int i)
102 {
103     /* Adjust the offset of the alias region we use for
104      * the memory window i to account for a change in the
105      * value of the corresponding IMAP register.
106      * Note that the semantics of the IMAP register differ
107      * for realview and versatile variants of the controller.
108      */
109     hwaddr offset;
110     if (s->realview) {
111         /* Top bits of register (masked according to window size) provide
112          * top bits of PCI address.
113          */
114         offset = s->imap[i] & ~(s->mem_win_size[i] - 1);
115     } else {
116         /* Bottom 4 bits of register provide top 4 bits of PCI address */
117         offset = s->imap[i] << 28;
118     }
119     memory_region_set_alias_offset(&s->pci_mem_window[i], offset);
120 }
121 
122 static void pci_vpb_update_all_windows(PCIVPBState *s)
123 {
124     /* Update all alias windows based on the current register state */
125     int i;
126 
127     for (i = 0; i < 3; i++) {
128         pci_vpb_update_window(s, i);
129     }
130 }
131 
132 static int pci_vpb_post_load(void *opaque, int version_id)
133 {
134     PCIVPBState *s = opaque;
135     pci_vpb_update_all_windows(s);
136     return 0;
137 }
138 
139 static const VMStateDescription pci_vpb_vmstate = {
140     .name = "versatile-pci",
141     .version_id = 1,
142     .minimum_version_id = 1,
143     .post_load = pci_vpb_post_load,
144     .fields = (VMStateField[]) {
145         VMSTATE_UINT32_ARRAY(imap, PCIVPBState, 3),
146         VMSTATE_UINT32_ARRAY(smap, PCIVPBState, 3),
147         VMSTATE_UINT32(selfid, PCIVPBState),
148         VMSTATE_UINT32(flags, PCIVPBState),
149         VMSTATE_UINT8(irq_mapping, PCIVPBState),
150         VMSTATE_END_OF_LIST()
151     }
152 };
153 
154 #define TYPE_VERSATILE_PCI "versatile_pci"
155 #define PCI_VPB(obj) \
156     OBJECT_CHECK(PCIVPBState, (obj), TYPE_VERSATILE_PCI)
157 
158 #define TYPE_VERSATILE_PCI_HOST "versatile_pci_host"
159 #define PCI_VPB_HOST(obj) \
160     OBJECT_CHECK(PCIDevice, (obj), TYPE_VERSATILE_PCIHOST)
161 
162 typedef enum {
163     PCI_IMAP0 = 0x0,
164     PCI_IMAP1 = 0x4,
165     PCI_IMAP2 = 0x8,
166     PCI_SELFID = 0xc,
167     PCI_FLAGS = 0x10,
168     PCI_SMAP0 = 0x14,
169     PCI_SMAP1 = 0x18,
170     PCI_SMAP2 = 0x1c,
171 } PCIVPBControlRegs;
172 
173 static void pci_vpb_reg_write(void *opaque, hwaddr addr,
174                               uint64_t val, unsigned size)
175 {
176     PCIVPBState *s = opaque;
177 
178     switch (addr) {
179     case PCI_IMAP0:
180     case PCI_IMAP1:
181     case PCI_IMAP2:
182     {
183         int win = (addr - PCI_IMAP0) >> 2;
184         s->imap[win] = val;
185         pci_vpb_update_window(s, win);
186         break;
187     }
188     case PCI_SELFID:
189         s->selfid = val;
190         break;
191     case PCI_FLAGS:
192         s->flags = val;
193         break;
194     case PCI_SMAP0:
195     case PCI_SMAP1:
196     case PCI_SMAP2:
197     {
198         int win = (addr - PCI_SMAP0) >> 2;
199         s->smap[win] = val;
200         break;
201     }
202     default:
203         qemu_log_mask(LOG_GUEST_ERROR,
204                       "pci_vpb_reg_write: Bad offset %x\n", (int)addr);
205         break;
206     }
207 }
208 
209 static uint64_t pci_vpb_reg_read(void *opaque, hwaddr addr,
210                                  unsigned size)
211 {
212     PCIVPBState *s = opaque;
213 
214     switch (addr) {
215     case PCI_IMAP0:
216     case PCI_IMAP1:
217     case PCI_IMAP2:
218     {
219         int win = (addr - PCI_IMAP0) >> 2;
220         return s->imap[win];
221     }
222     case PCI_SELFID:
223         return s->selfid;
224     case PCI_FLAGS:
225         return s->flags;
226     case PCI_SMAP0:
227     case PCI_SMAP1:
228     case PCI_SMAP2:
229     {
230         int win = (addr - PCI_SMAP0) >> 2;
231         return s->smap[win];
232     }
233     default:
234         qemu_log_mask(LOG_GUEST_ERROR,
235                       "pci_vpb_reg_read: Bad offset %x\n", (int)addr);
236         return 0;
237     }
238 }
239 
240 static const MemoryRegionOps pci_vpb_reg_ops = {
241     .read = pci_vpb_reg_read,
242     .write = pci_vpb_reg_write,
243     .endianness = DEVICE_NATIVE_ENDIAN,
244     .valid = {
245         .min_access_size = 4,
246         .max_access_size = 4,
247     },
248 };
249 
250 static int pci_vpb_broken_irq(int slot, int irq)
251 {
252     /* Determine whether this IRQ value for this slot represents a
253      * known broken Linux kernel behaviour for this slot.
254      * Return one of the PCI_VPB_IRQMAP_ constants:
255      *   BROKEN : if this definitely looks like a broken kernel
256      *   FORCE_OK : if this definitely looks good
257      *   ASSUME_OK : if we can't tell
258      */
259     slot %= PCI_NUM_PINS;
260 
261     if (irq == 27) {
262         if (slot == 2) {
263             /* Might be a Phase I kernel, or might be a fixed kernel,
264              * since slot 2 is where we expect this IRQ.
265              */
266             return PCI_VPB_IRQMAP_ASSUME_OK;
267         }
268         /* Phase I kernel */
269         return PCI_VPB_IRQMAP_BROKEN;
270     }
271     if (irq == slot + 27) {
272         /* Phase II kernel */
273         return PCI_VPB_IRQMAP_BROKEN;
274     }
275     if (irq == slot + 27 + 64) {
276         /* Phase III kernel */
277         return PCI_VPB_IRQMAP_BROKEN;
278     }
279     /* Anything else must be a fixed kernel, possibly using an
280      * arbitrary irq map.
281      */
282     return PCI_VPB_IRQMAP_FORCE_OK;
283 }
284 
285 static void pci_vpb_config_write(void *opaque, hwaddr addr,
286                                  uint64_t val, unsigned size)
287 {
288     PCIVPBState *s = opaque;
289     if (!s->realview && (addr & 0xff) == PCI_INTERRUPT_LINE
290         && s->irq_mapping == PCI_VPB_IRQMAP_ASSUME_OK) {
291         uint8_t devfn = addr >> 8;
292         s->irq_mapping = pci_vpb_broken_irq(PCI_SLOT(devfn), val);
293     }
294     pci_data_write(&s->pci_bus, addr, val, size);
295 }
296 
297 static uint64_t pci_vpb_config_read(void *opaque, hwaddr addr,
298                                     unsigned size)
299 {
300     PCIVPBState *s = opaque;
301     uint32_t val;
302     val = pci_data_read(&s->pci_bus, addr, size);
303     return val;
304 }
305 
306 static const MemoryRegionOps pci_vpb_config_ops = {
307     .read = pci_vpb_config_read,
308     .write = pci_vpb_config_write,
309     .endianness = DEVICE_NATIVE_ENDIAN,
310 };
311 
312 static int pci_vpb_map_irq(PCIDevice *d, int irq_num)
313 {
314     PCIVPBState *s = container_of(d->bus, PCIVPBState, pci_bus);
315 
316     if (s->irq_mapping == PCI_VPB_IRQMAP_BROKEN) {
317         /* Legacy broken IRQ mapping for compatibility with old and
318          * buggy Linux guests
319          */
320         return irq_num;
321     }
322 
323     /* Slot to IRQ mapping for RealView Platform Baseboard 926 backplane
324      *      name    slot    IntA    IntB    IntC    IntD
325      *      A       31      IRQ28   IRQ29   IRQ30   IRQ27
326      *      B       30      IRQ27   IRQ28   IRQ29   IRQ30
327      *      C       29      IRQ30   IRQ27   IRQ28   IRQ29
328      * Slot C is for the host bridge; A and B the peripherals.
329      * Our output irqs 0..3 correspond to the baseboard's 27..30.
330      *
331      * This mapping function takes account of an oddity in the PB926
332      * board wiring, where the FPGA's P_nINTA input is connected to
333      * the INTB connection on the board PCI edge connector, P_nINTB
334      * is connected to INTC, and so on, so everything is one number
335      * further round from where you might expect.
336      */
337     return pci_swizzle_map_irq_fn(d, irq_num + 2);
338 }
339 
340 static int pci_vpb_rv_map_irq(PCIDevice *d, int irq_num)
341 {
342     /* Slot to IRQ mapping for RealView EB and PB1176 backplane
343      *      name    slot    IntA    IntB    IntC    IntD
344      *      A       31      IRQ50   IRQ51   IRQ48   IRQ49
345      *      B       30      IRQ49   IRQ50   IRQ51   IRQ48
346      *      C       29      IRQ48   IRQ49   IRQ50   IRQ51
347      * Slot C is for the host bridge; A and B the peripherals.
348      * Our output irqs 0..3 correspond to the baseboard's 48..51.
349      *
350      * The PB1176 and EB boards don't have the PB926 wiring oddity
351      * described above; P_nINTA connects to INTA, P_nINTB to INTB
352      * and so on, which is why this mapping function is different.
353      */
354     return pci_swizzle_map_irq_fn(d, irq_num + 3);
355 }
356 
357 static void pci_vpb_set_irq(void *opaque, int irq_num, int level)
358 {
359     qemu_irq *pic = opaque;
360 
361     qemu_set_irq(pic[irq_num], level);
362 }
363 
364 static void pci_vpb_reset(DeviceState *d)
365 {
366     PCIVPBState *s = PCI_VPB(d);
367 
368     s->imap[0] = 0;
369     s->imap[1] = 0;
370     s->imap[2] = 0;
371     s->smap[0] = 0;
372     s->smap[1] = 0;
373     s->smap[2] = 0;
374     s->selfid = 0;
375     s->flags = 0;
376     s->irq_mapping = s->irq_mapping_prop;
377 
378     pci_vpb_update_all_windows(s);
379 }
380 
381 static void pci_vpb_init(Object *obj)
382 {
383     PCIHostState *h = PCI_HOST_BRIDGE(obj);
384     PCIVPBState *s = PCI_VPB(obj);
385 
386     memory_region_init(&s->pci_io_space, OBJECT(s), "pci_io", 1ULL << 32);
387     memory_region_init(&s->pci_mem_space, OBJECT(s), "pci_mem", 1ULL << 32);
388 
389     pci_bus_new_inplace(&s->pci_bus, sizeof(s->pci_bus), DEVICE(obj), "pci",
390                         &s->pci_mem_space, &s->pci_io_space,
391                         PCI_DEVFN(11, 0), TYPE_PCI_BUS);
392     h->bus = &s->pci_bus;
393 
394     object_initialize(&s->pci_dev, sizeof(s->pci_dev), TYPE_VERSATILE_PCI_HOST);
395     qdev_set_parent_bus(DEVICE(&s->pci_dev), BUS(&s->pci_bus));
396 
397     /* Window sizes for VersatilePB; realview_pci's init will override */
398     s->mem_win_size[0] = 0x0c000000;
399     s->mem_win_size[1] = 0x10000000;
400     s->mem_win_size[2] = 0x10000000;
401 }
402 
403 static void pci_vpb_realize(DeviceState *dev, Error **errp)
404 {
405     PCIVPBState *s = PCI_VPB(dev);
406     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
407     pci_map_irq_fn mapfn;
408     int i;
409 
410     for (i = 0; i < 4; i++) {
411         sysbus_init_irq(sbd, &s->irq[i]);
412     }
413 
414     if (s->realview) {
415         mapfn = pci_vpb_rv_map_irq;
416     } else {
417         mapfn = pci_vpb_map_irq;
418     }
419 
420     pci_bus_irqs(&s->pci_bus, pci_vpb_set_irq, mapfn, s->irq, 4);
421 
422     /* Our memory regions are:
423      * 0 : our control registers
424      * 1 : PCI self config window
425      * 2 : PCI config window
426      * 3 : PCI IO window
427      * 4..6 : PCI memory windows
428      */
429     memory_region_init_io(&s->controlregs, OBJECT(s), &pci_vpb_reg_ops, s,
430                           "pci-vpb-regs", 0x1000);
431     sysbus_init_mmio(sbd, &s->controlregs);
432     memory_region_init_io(&s->mem_config, OBJECT(s), &pci_vpb_config_ops, s,
433                           "pci-vpb-selfconfig", 0x1000000);
434     sysbus_init_mmio(sbd, &s->mem_config);
435     memory_region_init_io(&s->mem_config2, OBJECT(s), &pci_vpb_config_ops, s,
436                           "pci-vpb-config", 0x1000000);
437     sysbus_init_mmio(sbd, &s->mem_config2);
438 
439     /* The window into I/O space is always into a fixed base address;
440      * its size is the same for both realview and versatile.
441      */
442     memory_region_init_alias(&s->pci_io_window, OBJECT(s), "pci-vbp-io-window",
443                              &s->pci_io_space, 0, 0x100000);
444 
445     sysbus_init_mmio(sbd, &s->pci_io_space);
446 
447     /* Create the alias regions corresponding to our three windows onto
448      * PCI memory space. The sizes vary from board to board; the base
449      * offsets are guest controllable via the IMAP registers.
450      */
451     for (i = 0; i < 3; i++) {
452         memory_region_init_alias(&s->pci_mem_window[i], OBJECT(s), "pci-vbp-window",
453                                  &s->pci_mem_space, 0, s->mem_win_size[i]);
454         sysbus_init_mmio(sbd, &s->pci_mem_window[i]);
455     }
456 
457     /* TODO Remove once realize propagates to child devices. */
458     object_property_set_bool(OBJECT(&s->pci_bus), true, "realized", errp);
459     object_property_set_bool(OBJECT(&s->pci_dev), true, "realized", errp);
460 }
461 
462 static void versatile_pci_host_realize(PCIDevice *d, Error **errp)
463 {
464     pci_set_word(d->config + PCI_STATUS,
465                  PCI_STATUS_66MHZ | PCI_STATUS_DEVSEL_MEDIUM);
466     pci_set_byte(d->config + PCI_LATENCY_TIMER, 0x10);
467 }
468 
469 static void versatile_pci_host_class_init(ObjectClass *klass, void *data)
470 {
471     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
472     DeviceClass *dc = DEVICE_CLASS(klass);
473 
474     k->realize = versatile_pci_host_realize;
475     k->vendor_id = PCI_VENDOR_ID_XILINX;
476     k->device_id = PCI_DEVICE_ID_XILINX_XC2VP30;
477     k->class_id = PCI_CLASS_PROCESSOR_CO;
478     /*
479      * PCI-facing part of the host bridge, not usable without the
480      * host-facing part, which can't be device_add'ed, yet.
481      */
482     dc->cannot_instantiate_with_device_add_yet = true;
483 }
484 
485 static const TypeInfo versatile_pci_host_info = {
486     .name          = TYPE_VERSATILE_PCI_HOST,
487     .parent        = TYPE_PCI_DEVICE,
488     .instance_size = sizeof(PCIDevice),
489     .class_init    = versatile_pci_host_class_init,
490 };
491 
492 static Property pci_vpb_properties[] = {
493     DEFINE_PROP_UINT8("broken-irq-mapping", PCIVPBState, irq_mapping_prop,
494                       PCI_VPB_IRQMAP_ASSUME_OK),
495     DEFINE_PROP_END_OF_LIST()
496 };
497 
498 static void pci_vpb_class_init(ObjectClass *klass, void *data)
499 {
500     DeviceClass *dc = DEVICE_CLASS(klass);
501 
502     dc->realize = pci_vpb_realize;
503     dc->reset = pci_vpb_reset;
504     dc->vmsd = &pci_vpb_vmstate;
505     dc->props = pci_vpb_properties;
506     /* Reason: object_unref() hangs */
507     dc->cannot_destroy_with_object_finalize_yet = true;
508 }
509 
510 static const TypeInfo pci_vpb_info = {
511     .name          = TYPE_VERSATILE_PCI,
512     .parent        = TYPE_PCI_HOST_BRIDGE,
513     .instance_size = sizeof(PCIVPBState),
514     .instance_init = pci_vpb_init,
515     .class_init    = pci_vpb_class_init,
516 };
517 
518 static void pci_realview_init(Object *obj)
519 {
520     PCIVPBState *s = PCI_VPB(obj);
521 
522     s->realview = 1;
523     /* The PCI window sizes are different on Realview boards */
524     s->mem_win_size[0] = 0x01000000;
525     s->mem_win_size[1] = 0x04000000;
526     s->mem_win_size[2] = 0x08000000;
527 }
528 
529 static void pci_realview_class_init(ObjectClass *class, void *data)
530 {
531     DeviceClass *dc = DEVICE_CLASS(class);
532 
533     /* Reason: object_unref() hangs */
534     dc->cannot_destroy_with_object_finalize_yet = true;
535 }
536 
537 static const TypeInfo pci_realview_info = {
538     .name          = "realview_pci",
539     .parent        = TYPE_VERSATILE_PCI,
540     .instance_init = pci_realview_init,
541     .class_init    = pci_realview_class_init,
542 };
543 
544 static void versatile_pci_register_types(void)
545 {
546     type_register_static(&pci_vpb_info);
547     type_register_static(&pci_realview_info);
548     type_register_static(&versatile_pci_host_info);
549 }
550 
551 type_init(versatile_pci_register_types)
552