xref: /openbmc/qemu/hw/pci-host/versatile.c (revision 135b03cb)
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 "migration/vmstate.h"
13 #include "hw/irq.h"
14 #include "hw/pci/pci.h"
15 #include "hw/pci/pci_bus.h"
16 #include "hw/pci/pci_host.h"
17 #include "hw/qdev-properties.h"
18 #include "qemu/log.h"
19 #include "qemu/module.h"
20 
21 /* Old and buggy versions of QEMU used the wrong mapping from
22  * PCI IRQs to system interrupt lines. Unfortunately the Linux
23  * kernel also had the corresponding bug in setting up interrupts
24  * (so older kernels work on QEMU and not on real hardware).
25  * We automatically detect these broken kernels and flip back
26  * to the broken irq mapping by spotting guest writes to the
27  * PCI_INTERRUPT_LINE register to see where the guest thinks
28  * interrupts are going to be routed. So we start in state
29  * ASSUME_OK on reset, and transition to either BROKEN or
30  * FORCE_OK at the first write to an INTERRUPT_LINE register for
31  * a slot where broken and correct interrupt mapping would differ.
32  * Once in either BROKEN or FORCE_OK we never transition again;
33  * this allows a newer kernel to use the INTERRUPT_LINE
34  * registers arbitrarily once it has indicated that it isn't
35  * broken in its init code somewhere.
36  *
37  * Unfortunately we have to cope with multiple different
38  * variants on the broken kernel behaviour:
39  *  phase I (before kernel commit 1bc39ac5d) kernels assume old
40  *   QEMU behaviour, so they use IRQ 27 for all slots
41  *  phase II (1bc39ac5d and later, but before e3e92a7be6) kernels
42  *   swizzle IRQs between slots, but do it wrongly, so they
43  *   work only for every fourth PCI card, and only if (like old
44  *   QEMU) the PCI host device is at slot 0 rather than where
45  *   the h/w actually puts it
46  *  phase III (e3e92a7be6 and later) kernels still swizzle IRQs between
47  *   slots wrongly, but add a fixed offset of 64 to everything
48  *   they write to PCI_INTERRUPT_LINE.
49  *
50  * We live in hope of a mythical phase IV kernel which might
51  * actually behave in ways that work on the hardware. Such a
52  * kernel should probably start off by writing some value neither
53  * 27 nor 91 to slot zero's PCI_INTERRUPT_LINE register to
54  * disable the autodetection. After that it can do what it likes.
55  *
56  * Slot % 4 | hw | I  | II | III
57  * -------------------------------
58  *   0      | 29 | 27 | 27 | 91
59  *   1      | 30 | 27 | 28 | 92
60  *   2      | 27 | 27 | 29 | 93
61  *   3      | 28 | 27 | 30 | 94
62  *
63  * Since our autodetection is not perfect we also provide a
64  * property so the user can make us start in BROKEN or FORCE_OK
65  * on reset if they know they have a bad or good kernel.
66  */
67 enum {
68     PCI_VPB_IRQMAP_ASSUME_OK,
69     PCI_VPB_IRQMAP_BROKEN,
70     PCI_VPB_IRQMAP_FORCE_OK,
71 };
72 
73 typedef struct {
74     PCIHostState parent_obj;
75 
76     qemu_irq irq[4];
77     MemoryRegion controlregs;
78     MemoryRegion mem_config;
79     MemoryRegion mem_config2;
80     /* Containers representing the PCI address spaces */
81     MemoryRegion pci_io_space;
82     MemoryRegion pci_mem_space;
83     /* Alias regions into PCI address spaces which we expose as sysbus regions.
84      * The offsets into pci_mem_space are controlled by the imap registers.
85      */
86     MemoryRegion pci_io_window;
87     MemoryRegion pci_mem_window[3];
88     PCIBus pci_bus;
89     PCIDevice pci_dev;
90 
91     /* Constant for life of device: */
92     int realview;
93     uint32_t mem_win_size[3];
94     uint8_t irq_mapping_prop;
95 
96     /* Variable state: */
97     uint32_t imap[3];
98     uint32_t smap[3];
99     uint32_t selfid;
100     uint32_t flags;
101     uint8_t irq_mapping;
102 } PCIVPBState;
103 
104 static void pci_vpb_update_window(PCIVPBState *s, int i)
105 {
106     /* Adjust the offset of the alias region we use for
107      * the memory window i to account for a change in the
108      * value of the corresponding IMAP register.
109      * Note that the semantics of the IMAP register differ
110      * for realview and versatile variants of the controller.
111      */
112     hwaddr offset;
113     if (s->realview) {
114         /* Top bits of register (masked according to window size) provide
115          * top bits of PCI address.
116          */
117         offset = s->imap[i] & ~(s->mem_win_size[i] - 1);
118     } else {
119         /* Bottom 4 bits of register provide top 4 bits of PCI address */
120         offset = s->imap[i] << 28;
121     }
122     memory_region_set_alias_offset(&s->pci_mem_window[i], offset);
123 }
124 
125 static void pci_vpb_update_all_windows(PCIVPBState *s)
126 {
127     /* Update all alias windows based on the current register state */
128     int i;
129 
130     for (i = 0; i < 3; i++) {
131         pci_vpb_update_window(s, i);
132     }
133 }
134 
135 static int pci_vpb_post_load(void *opaque, int version_id)
136 {
137     PCIVPBState *s = opaque;
138     pci_vpb_update_all_windows(s);
139     return 0;
140 }
141 
142 static const VMStateDescription pci_vpb_vmstate = {
143     .name = "versatile-pci",
144     .version_id = 1,
145     .minimum_version_id = 1,
146     .post_load = pci_vpb_post_load,
147     .fields = (VMStateField[]) {
148         VMSTATE_UINT32_ARRAY(imap, PCIVPBState, 3),
149         VMSTATE_UINT32_ARRAY(smap, PCIVPBState, 3),
150         VMSTATE_UINT32(selfid, PCIVPBState),
151         VMSTATE_UINT32(flags, PCIVPBState),
152         VMSTATE_UINT8(irq_mapping, PCIVPBState),
153         VMSTATE_END_OF_LIST()
154     }
155 };
156 
157 #define TYPE_VERSATILE_PCI "versatile_pci"
158 #define PCI_VPB(obj) \
159     OBJECT_CHECK(PCIVPBState, (obj), TYPE_VERSATILE_PCI)
160 
161 #define TYPE_VERSATILE_PCI_HOST "versatile_pci_host"
162 #define PCI_VPB_HOST(obj) \
163     OBJECT_CHECK(PCIDevice, (obj), TYPE_VERSATILE_PCIHOST)
164 
165 typedef enum {
166     PCI_IMAP0 = 0x0,
167     PCI_IMAP1 = 0x4,
168     PCI_IMAP2 = 0x8,
169     PCI_SELFID = 0xc,
170     PCI_FLAGS = 0x10,
171     PCI_SMAP0 = 0x14,
172     PCI_SMAP1 = 0x18,
173     PCI_SMAP2 = 0x1c,
174 } PCIVPBControlRegs;
175 
176 static void pci_vpb_reg_write(void *opaque, hwaddr addr,
177                               uint64_t val, unsigned size)
178 {
179     PCIVPBState *s = opaque;
180 
181     switch (addr) {
182     case PCI_IMAP0:
183     case PCI_IMAP1:
184     case PCI_IMAP2:
185     {
186         int win = (addr - PCI_IMAP0) >> 2;
187         s->imap[win] = val;
188         pci_vpb_update_window(s, win);
189         break;
190     }
191     case PCI_SELFID:
192         s->selfid = val;
193         break;
194     case PCI_FLAGS:
195         s->flags = val;
196         break;
197     case PCI_SMAP0:
198     case PCI_SMAP1:
199     case PCI_SMAP2:
200     {
201         int win = (addr - PCI_SMAP0) >> 2;
202         s->smap[win] = val;
203         break;
204     }
205     default:
206         qemu_log_mask(LOG_GUEST_ERROR,
207                       "pci_vpb_reg_write: Bad offset %x\n", (int)addr);
208         break;
209     }
210 }
211 
212 static uint64_t pci_vpb_reg_read(void *opaque, hwaddr addr,
213                                  unsigned size)
214 {
215     PCIVPBState *s = opaque;
216 
217     switch (addr) {
218     case PCI_IMAP0:
219     case PCI_IMAP1:
220     case PCI_IMAP2:
221     {
222         int win = (addr - PCI_IMAP0) >> 2;
223         return s->imap[win];
224     }
225     case PCI_SELFID:
226         return s->selfid;
227     case PCI_FLAGS:
228         return s->flags;
229     case PCI_SMAP0:
230     case PCI_SMAP1:
231     case PCI_SMAP2:
232     {
233         int win = (addr - PCI_SMAP0) >> 2;
234         return s->smap[win];
235     }
236     default:
237         qemu_log_mask(LOG_GUEST_ERROR,
238                       "pci_vpb_reg_read: Bad offset %x\n", (int)addr);
239         return 0;
240     }
241 }
242 
243 static const MemoryRegionOps pci_vpb_reg_ops = {
244     .read = pci_vpb_reg_read,
245     .write = pci_vpb_reg_write,
246     .endianness = DEVICE_NATIVE_ENDIAN,
247     .valid = {
248         .min_access_size = 4,
249         .max_access_size = 4,
250     },
251 };
252 
253 static int pci_vpb_broken_irq(int slot, int irq)
254 {
255     /* Determine whether this IRQ value for this slot represents a
256      * known broken Linux kernel behaviour for this slot.
257      * Return one of the PCI_VPB_IRQMAP_ constants:
258      *   BROKEN : if this definitely looks like a broken kernel
259      *   FORCE_OK : if this definitely looks good
260      *   ASSUME_OK : if we can't tell
261      */
262     slot %= PCI_NUM_PINS;
263 
264     if (irq == 27) {
265         if (slot == 2) {
266             /* Might be a Phase I kernel, or might be a fixed kernel,
267              * since slot 2 is where we expect this IRQ.
268              */
269             return PCI_VPB_IRQMAP_ASSUME_OK;
270         }
271         /* Phase I kernel */
272         return PCI_VPB_IRQMAP_BROKEN;
273     }
274     if (irq == slot + 27) {
275         /* Phase II kernel */
276         return PCI_VPB_IRQMAP_BROKEN;
277     }
278     if (irq == slot + 27 + 64) {
279         /* Phase III kernel */
280         return PCI_VPB_IRQMAP_BROKEN;
281     }
282     /* Anything else must be a fixed kernel, possibly using an
283      * arbitrary irq map.
284      */
285     return PCI_VPB_IRQMAP_FORCE_OK;
286 }
287 
288 static void pci_vpb_config_write(void *opaque, hwaddr addr,
289                                  uint64_t val, unsigned size)
290 {
291     PCIVPBState *s = opaque;
292     if (!s->realview && (addr & 0xff) == PCI_INTERRUPT_LINE
293         && s->irq_mapping == PCI_VPB_IRQMAP_ASSUME_OK) {
294         uint8_t devfn = addr >> 8;
295         s->irq_mapping = pci_vpb_broken_irq(PCI_SLOT(devfn), val);
296     }
297     pci_data_write(&s->pci_bus, addr, val, size);
298 }
299 
300 static uint64_t pci_vpb_config_read(void *opaque, hwaddr addr,
301                                     unsigned size)
302 {
303     PCIVPBState *s = opaque;
304     uint32_t val;
305     val = pci_data_read(&s->pci_bus, addr, size);
306     return val;
307 }
308 
309 static const MemoryRegionOps pci_vpb_config_ops = {
310     .read = pci_vpb_config_read,
311     .write = pci_vpb_config_write,
312     .endianness = DEVICE_NATIVE_ENDIAN,
313 };
314 
315 static int pci_vpb_map_irq(PCIDevice *d, int irq_num)
316 {
317     PCIVPBState *s = container_of(pci_get_bus(d), PCIVPBState, pci_bus);
318 
319     if (s->irq_mapping == PCI_VPB_IRQMAP_BROKEN) {
320         /* Legacy broken IRQ mapping for compatibility with old and
321          * buggy Linux guests
322          */
323         return irq_num;
324     }
325 
326     /* Slot to IRQ mapping for RealView Platform Baseboard 926 backplane
327      *      name    slot    IntA    IntB    IntC    IntD
328      *      A       31      IRQ28   IRQ29   IRQ30   IRQ27
329      *      B       30      IRQ27   IRQ28   IRQ29   IRQ30
330      *      C       29      IRQ30   IRQ27   IRQ28   IRQ29
331      * Slot C is for the host bridge; A and B the peripherals.
332      * Our output irqs 0..3 correspond to the baseboard's 27..30.
333      *
334      * This mapping function takes account of an oddity in the PB926
335      * board wiring, where the FPGA's P_nINTA input is connected to
336      * the INTB connection on the board PCI edge connector, P_nINTB
337      * is connected to INTC, and so on, so everything is one number
338      * further round from where you might expect.
339      */
340     return pci_swizzle_map_irq_fn(d, irq_num + 2);
341 }
342 
343 static int pci_vpb_rv_map_irq(PCIDevice *d, int irq_num)
344 {
345     /* Slot to IRQ mapping for RealView EB and PB1176 backplane
346      *      name    slot    IntA    IntB    IntC    IntD
347      *      A       31      IRQ50   IRQ51   IRQ48   IRQ49
348      *      B       30      IRQ49   IRQ50   IRQ51   IRQ48
349      *      C       29      IRQ48   IRQ49   IRQ50   IRQ51
350      * Slot C is for the host bridge; A and B the peripherals.
351      * Our output irqs 0..3 correspond to the baseboard's 48..51.
352      *
353      * The PB1176 and EB boards don't have the PB926 wiring oddity
354      * described above; P_nINTA connects to INTA, P_nINTB to INTB
355      * and so on, which is why this mapping function is different.
356      */
357     return pci_swizzle_map_irq_fn(d, irq_num + 3);
358 }
359 
360 static void pci_vpb_set_irq(void *opaque, int irq_num, int level)
361 {
362     qemu_irq *pic = opaque;
363 
364     qemu_set_irq(pic[irq_num], level);
365 }
366 
367 static void pci_vpb_reset(DeviceState *d)
368 {
369     PCIVPBState *s = PCI_VPB(d);
370 
371     s->imap[0] = 0;
372     s->imap[1] = 0;
373     s->imap[2] = 0;
374     s->smap[0] = 0;
375     s->smap[1] = 0;
376     s->smap[2] = 0;
377     s->selfid = 0;
378     s->flags = 0;
379     s->irq_mapping = s->irq_mapping_prop;
380 
381     pci_vpb_update_all_windows(s);
382 }
383 
384 static void pci_vpb_init(Object *obj)
385 {
386     PCIVPBState *s = PCI_VPB(obj);
387 
388     /* Window sizes for VersatilePB; realview_pci's init will override */
389     s->mem_win_size[0] = 0x0c000000;
390     s->mem_win_size[1] = 0x10000000;
391     s->mem_win_size[2] = 0x10000000;
392 }
393 
394 static void pci_vpb_realize(DeviceState *dev, Error **errp)
395 {
396     PCIVPBState *s = PCI_VPB(dev);
397     PCIHostState *h = PCI_HOST_BRIDGE(dev);
398     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
399     pci_map_irq_fn mapfn;
400     int i;
401 
402     memory_region_init(&s->pci_io_space, OBJECT(s), "pci_io", 1ULL << 32);
403     memory_region_init(&s->pci_mem_space, OBJECT(s), "pci_mem", 1ULL << 32);
404 
405     pci_root_bus_new_inplace(&s->pci_bus, sizeof(s->pci_bus), dev, "pci",
406                              &s->pci_mem_space, &s->pci_io_space,
407                              PCI_DEVFN(11, 0), TYPE_PCI_BUS);
408     h->bus = &s->pci_bus;
409 
410     object_initialize(&s->pci_dev, sizeof(s->pci_dev), TYPE_VERSATILE_PCI_HOST);
411     qdev_set_parent_bus(DEVICE(&s->pci_dev), BUS(&s->pci_bus));
412 
413     for (i = 0; i < 4; i++) {
414         sysbus_init_irq(sbd, &s->irq[i]);
415     }
416 
417     if (s->realview) {
418         mapfn = pci_vpb_rv_map_irq;
419     } else {
420         mapfn = pci_vpb_map_irq;
421     }
422 
423     pci_bus_irqs(&s->pci_bus, pci_vpb_set_irq, mapfn, s->irq, 4);
424 
425     /* Our memory regions are:
426      * 0 : our control registers
427      * 1 : PCI self config window
428      * 2 : PCI config window
429      * 3 : PCI IO window
430      * 4..6 : PCI memory windows
431      */
432     memory_region_init_io(&s->controlregs, OBJECT(s), &pci_vpb_reg_ops, s,
433                           "pci-vpb-regs", 0x1000);
434     sysbus_init_mmio(sbd, &s->controlregs);
435     memory_region_init_io(&s->mem_config, OBJECT(s), &pci_vpb_config_ops, s,
436                           "pci-vpb-selfconfig", 0x1000000);
437     sysbus_init_mmio(sbd, &s->mem_config);
438     memory_region_init_io(&s->mem_config2, OBJECT(s), &pci_vpb_config_ops, s,
439                           "pci-vpb-config", 0x1000000);
440     sysbus_init_mmio(sbd, &s->mem_config2);
441 
442     /* The window into I/O space is always into a fixed base address;
443      * its size is the same for both realview and versatile.
444      */
445     memory_region_init_alias(&s->pci_io_window, OBJECT(s), "pci-vbp-io-window",
446                              &s->pci_io_space, 0, 0x100000);
447 
448     sysbus_init_mmio(sbd, &s->pci_io_space);
449 
450     /* Create the alias regions corresponding to our three windows onto
451      * PCI memory space. The sizes vary from board to board; the base
452      * offsets are guest controllable via the IMAP registers.
453      */
454     for (i = 0; i < 3; i++) {
455         memory_region_init_alias(&s->pci_mem_window[i], OBJECT(s), "pci-vbp-window",
456                                  &s->pci_mem_space, 0, s->mem_win_size[i]);
457         sysbus_init_mmio(sbd, &s->pci_mem_window[i]);
458     }
459 
460     /* TODO Remove once realize propagates to child devices. */
461     object_property_set_bool(OBJECT(&s->pci_bus), true, "realized", errp);
462     object_property_set_bool(OBJECT(&s->pci_dev), true, "realized", errp);
463 }
464 
465 static void versatile_pci_host_realize(PCIDevice *d, Error **errp)
466 {
467     pci_set_word(d->config + PCI_STATUS,
468                  PCI_STATUS_66MHZ | PCI_STATUS_DEVSEL_MEDIUM);
469     pci_set_byte(d->config + PCI_LATENCY_TIMER, 0x10);
470 }
471 
472 static void versatile_pci_host_class_init(ObjectClass *klass, void *data)
473 {
474     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
475     DeviceClass *dc = DEVICE_CLASS(klass);
476 
477     k->realize = versatile_pci_host_realize;
478     k->vendor_id = PCI_VENDOR_ID_XILINX;
479     k->device_id = PCI_DEVICE_ID_XILINX_XC2VP30;
480     k->class_id = PCI_CLASS_PROCESSOR_CO;
481     /*
482      * PCI-facing part of the host bridge, not usable without the
483      * host-facing part, which can't be device_add'ed, yet.
484      */
485     dc->user_creatable = false;
486 }
487 
488 static const TypeInfo versatile_pci_host_info = {
489     .name          = TYPE_VERSATILE_PCI_HOST,
490     .parent        = TYPE_PCI_DEVICE,
491     .instance_size = sizeof(PCIDevice),
492     .class_init    = versatile_pci_host_class_init,
493     .interfaces = (InterfaceInfo[]) {
494         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
495         { },
496     },
497 };
498 
499 static Property pci_vpb_properties[] = {
500     DEFINE_PROP_UINT8("broken-irq-mapping", PCIVPBState, irq_mapping_prop,
501                       PCI_VPB_IRQMAP_ASSUME_OK),
502     DEFINE_PROP_END_OF_LIST()
503 };
504 
505 static void pci_vpb_class_init(ObjectClass *klass, void *data)
506 {
507     DeviceClass *dc = DEVICE_CLASS(klass);
508 
509     dc->realize = pci_vpb_realize;
510     dc->reset = pci_vpb_reset;
511     dc->vmsd = &pci_vpb_vmstate;
512     dc->props = pci_vpb_properties;
513 }
514 
515 static const TypeInfo pci_vpb_info = {
516     .name          = TYPE_VERSATILE_PCI,
517     .parent        = TYPE_PCI_HOST_BRIDGE,
518     .instance_size = sizeof(PCIVPBState),
519     .instance_init = pci_vpb_init,
520     .class_init    = pci_vpb_class_init,
521 };
522 
523 static void pci_realview_init(Object *obj)
524 {
525     PCIVPBState *s = PCI_VPB(obj);
526 
527     s->realview = 1;
528     /* The PCI window sizes are different on Realview boards */
529     s->mem_win_size[0] = 0x01000000;
530     s->mem_win_size[1] = 0x04000000;
531     s->mem_win_size[2] = 0x08000000;
532 }
533 
534 static const TypeInfo pci_realview_info = {
535     .name          = "realview_pci",
536     .parent        = TYPE_VERSATILE_PCI,
537     .instance_init = pci_realview_init,
538 };
539 
540 static void versatile_pci_register_types(void)
541 {
542     type_register_static(&pci_vpb_info);
543     type_register_static(&pci_realview_info);
544     type_register_static(&versatile_pci_host_info);
545 }
546 
547 type_init(versatile_pci_register_types)
548