xref: /openbmc/qemu/hw/alpha/typhoon.c (revision 88c1ee73)
1 /*
2  * DEC 21272 (TSUNAMI/TYPHOON) chipset emulation.
3  *
4  * Written by Richard Henderson.
5  *
6  * This work is licensed under the GNU GPL license version 2 or later.
7  */
8 
9 #include "cpu.h"
10 #include "hw/hw.h"
11 #include "hw/devices.h"
12 #include "sysemu/sysemu.h"
13 #include "alpha_sys.h"
14 #include "exec/address-spaces.h"
15 
16 
17 #define TYPE_TYPHOON_PCI_HOST_BRIDGE "typhoon-pcihost"
18 
19 typedef struct TyphoonCchip {
20     MemoryRegion region;
21     uint64_t misc;
22     uint64_t drir;
23     uint64_t dim[4];
24     uint32_t iic[4];
25     AlphaCPU *cpu[4];
26 } TyphoonCchip;
27 
28 typedef struct TyphoonWindow {
29     uint64_t wba;
30     uint64_t wsm;
31     uint64_t tba;
32 } TyphoonWindow;
33 
34 typedef struct TyphoonPchip {
35     MemoryRegion region;
36     MemoryRegion reg_iack;
37     MemoryRegion reg_mem;
38     MemoryRegion reg_io;
39     MemoryRegion reg_conf;
40 
41     AddressSpace iommu_as;
42     MemoryRegion iommu;
43 
44     uint64_t ctl;
45     TyphoonWindow win[4];
46 } TyphoonPchip;
47 
48 #define TYPHOON_PCI_HOST_BRIDGE(obj) \
49     OBJECT_CHECK(TyphoonState, (obj), TYPE_TYPHOON_PCI_HOST_BRIDGE)
50 
51 typedef struct TyphoonState {
52     PCIHostState parent_obj;
53 
54     TyphoonCchip cchip;
55     TyphoonPchip pchip;
56     MemoryRegion dchip_region;
57     MemoryRegion ram_region;
58 } TyphoonState;
59 
60 /* Called when one of DRIR or DIM changes.  */
61 static void cpu_irq_change(AlphaCPU *cpu, uint64_t req)
62 {
63     /* If there are any non-masked interrupts, tell the cpu.  */
64     if (cpu != NULL) {
65         CPUState *cs = CPU(cpu);
66         if (req) {
67             cpu_interrupt(cs, CPU_INTERRUPT_HARD);
68         } else {
69             cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
70         }
71     }
72 }
73 
74 static uint64_t cchip_read(void *opaque, hwaddr addr, unsigned size)
75 {
76     CPUState *cpu = current_cpu;
77     TyphoonState *s = opaque;
78     uint64_t ret = 0;
79 
80     switch (addr) {
81     case 0x0000:
82         /* CSC: Cchip System Configuration Register.  */
83         /* All sorts of data here; probably the only thing relevant is
84            PIP<14> Pchip 1 Present = 0.  */
85         break;
86 
87     case 0x0040:
88         /* MTR: Memory Timing Register.  */
89         /* All sorts of stuff related to real DRAM.  */
90         break;
91 
92     case 0x0080:
93         /* MISC: Miscellaneous Register.  */
94         ret = s->cchip.misc | (cpu->cpu_index & 3);
95         break;
96 
97     case 0x00c0:
98         /* MPD: Memory Presence Detect Register.  */
99         break;
100 
101     case 0x0100: /* AAR0 */
102     case 0x0140: /* AAR1 */
103     case 0x0180: /* AAR2 */
104     case 0x01c0: /* AAR3 */
105         /* AAR: Array Address Register.  */
106         /* All sorts of information about DRAM.  */
107         break;
108 
109     case 0x0200:
110         /* DIM0: Device Interrupt Mask Register, CPU0.  */
111         ret = s->cchip.dim[0];
112         break;
113     case 0x0240:
114         /* DIM1: Device Interrupt Mask Register, CPU1.  */
115         ret = s->cchip.dim[1];
116         break;
117     case 0x0280:
118         /* DIR0: Device Interrupt Request Register, CPU0.  */
119         ret = s->cchip.dim[0] & s->cchip.drir;
120         break;
121     case 0x02c0:
122         /* DIR1: Device Interrupt Request Register, CPU1.  */
123         ret = s->cchip.dim[1] & s->cchip.drir;
124         break;
125     case 0x0300:
126         /* DRIR: Device Raw Interrupt Request Register.  */
127         ret = s->cchip.drir;
128         break;
129 
130     case 0x0340:
131         /* PRBEN: Probe Enable Register.  */
132         break;
133 
134     case 0x0380:
135         /* IIC0: Interval Ignore Count Register, CPU0.  */
136         ret = s->cchip.iic[0];
137         break;
138     case 0x03c0:
139         /* IIC1: Interval Ignore Count Register, CPU1.  */
140         ret = s->cchip.iic[1];
141         break;
142 
143     case 0x0400: /* MPR0 */
144     case 0x0440: /* MPR1 */
145     case 0x0480: /* MPR2 */
146     case 0x04c0: /* MPR3 */
147         /* MPR: Memory Programming Register.  */
148         break;
149 
150     case 0x0580:
151         /* TTR: TIGbus Timing Register.  */
152         /* All sorts of stuff related to interrupt delivery timings.  */
153         break;
154     case 0x05c0:
155         /* TDR: TIGbug Device Timing Register.  */
156         break;
157 
158     case 0x0600:
159         /* DIM2: Device Interrupt Mask Register, CPU2.  */
160         ret = s->cchip.dim[2];
161         break;
162     case 0x0640:
163         /* DIM3: Device Interrupt Mask Register, CPU3.  */
164         ret = s->cchip.dim[3];
165         break;
166     case 0x0680:
167         /* DIR2: Device Interrupt Request Register, CPU2.  */
168         ret = s->cchip.dim[2] & s->cchip.drir;
169         break;
170     case 0x06c0:
171         /* DIR3: Device Interrupt Request Register, CPU3.  */
172         ret = s->cchip.dim[3] & s->cchip.drir;
173         break;
174 
175     case 0x0700:
176         /* IIC2: Interval Ignore Count Register, CPU2.  */
177         ret = s->cchip.iic[2];
178         break;
179     case 0x0740:
180         /* IIC3: Interval Ignore Count Register, CPU3.  */
181         ret = s->cchip.iic[3];
182         break;
183 
184     case 0x0780:
185         /* PWR: Power Management Control.   */
186         break;
187 
188     case 0x0c00: /* CMONCTLA */
189     case 0x0c40: /* CMONCTLB */
190     case 0x0c80: /* CMONCNT01 */
191     case 0x0cc0: /* CMONCNT23 */
192         break;
193 
194     default:
195         cpu_unassigned_access(cpu, addr, false, false, 0, size);
196         return -1;
197     }
198 
199     return ret;
200 }
201 
202 static uint64_t dchip_read(void *opaque, hwaddr addr, unsigned size)
203 {
204     /* Skip this.  It's all related to DRAM timing and setup.  */
205     return 0;
206 }
207 
208 static uint64_t pchip_read(void *opaque, hwaddr addr, unsigned size)
209 {
210     TyphoonState *s = opaque;
211     uint64_t ret = 0;
212 
213     switch (addr) {
214     case 0x0000:
215         /* WSBA0: Window Space Base Address Register.  */
216         ret = s->pchip.win[0].wba;
217         break;
218     case 0x0040:
219         /* WSBA1 */
220         ret = s->pchip.win[1].wba;
221         break;
222     case 0x0080:
223         /* WSBA2 */
224         ret = s->pchip.win[2].wba;
225         break;
226     case 0x00c0:
227         /* WSBA3 */
228         ret = s->pchip.win[3].wba;
229         break;
230 
231     case 0x0100:
232         /* WSM0: Window Space Mask Register.  */
233         ret = s->pchip.win[0].wsm;
234         break;
235     case 0x0140:
236         /* WSM1 */
237         ret = s->pchip.win[1].wsm;
238         break;
239     case 0x0180:
240         /* WSM2 */
241         ret = s->pchip.win[2].wsm;
242         break;
243     case 0x01c0:
244         /* WSM3 */
245         ret = s->pchip.win[3].wsm;
246         break;
247 
248     case 0x0200:
249         /* TBA0: Translated Base Address Register.  */
250         ret = s->pchip.win[0].tba;
251         break;
252     case 0x0240:
253         /* TBA1 */
254         ret = s->pchip.win[1].tba;
255         break;
256     case 0x0280:
257         /* TBA2 */
258         ret = s->pchip.win[2].tba;
259         break;
260     case 0x02c0:
261         /* TBA3 */
262         ret = s->pchip.win[3].tba;
263         break;
264 
265     case 0x0300:
266         /* PCTL: Pchip Control Register.  */
267         ret = s->pchip.ctl;
268         break;
269     case 0x0340:
270         /* PLAT: Pchip Master Latency Register.  */
271         break;
272     case 0x03c0:
273         /* PERROR: Pchip Error Register.  */
274         break;
275     case 0x0400:
276         /* PERRMASK: Pchip Error Mask Register.  */
277         break;
278     case 0x0440:
279         /* PERRSET: Pchip Error Set Register.  */
280         break;
281     case 0x0480:
282         /* TLBIV: Translation Buffer Invalidate Virtual Register (WO).  */
283         break;
284     case 0x04c0:
285         /* TLBIA: Translation Buffer Invalidate All Register (WO).  */
286         break;
287     case 0x0500: /* PMONCTL */
288     case 0x0540: /* PMONCNT */
289     case 0x0800: /* SPRST */
290         break;
291 
292     default:
293         cpu_unassigned_access(current_cpu, addr, false, false, 0, size);
294         return -1;
295     }
296 
297     return ret;
298 }
299 
300 static void cchip_write(void *opaque, hwaddr addr,
301                         uint64_t val, unsigned size)
302 {
303     TyphoonState *s = opaque;
304     uint64_t oldval, newval;
305 
306     switch (addr) {
307     case 0x0000:
308         /* CSC: Cchip System Configuration Register.  */
309         /* All sorts of data here; nothing relevant RW.  */
310         break;
311 
312     case 0x0040:
313         /* MTR: Memory Timing Register.  */
314         /* All sorts of stuff related to real DRAM.  */
315         break;
316 
317     case 0x0080:
318         /* MISC: Miscellaneous Register.  */
319         newval = oldval = s->cchip.misc;
320         newval &= ~(val & 0x10000ff0);     /* W1C fields */
321         if (val & 0x100000) {
322             newval &= ~0xff0000ull;        /* ACL clears ABT and ABW */
323         } else {
324             newval |= val & 0x00f00000;    /* ABT field is W1S */
325             if ((newval & 0xf0000) == 0) {
326                 newval |= val & 0xf0000;   /* ABW field is W1S iff zero */
327             }
328         }
329         newval |= (val & 0xf000) >> 4;     /* IPREQ field sets IPINTR.  */
330 
331         newval &= ~0xf0000000000ull;       /* WO and RW fields */
332         newval |= val & 0xf0000000000ull;
333         s->cchip.misc = newval;
334 
335         /* Pass on changes to IPI and ITI state.  */
336         if ((newval ^ oldval) & 0xff0) {
337             int i;
338             for (i = 0; i < 4; ++i) {
339                 AlphaCPU *cpu = s->cchip.cpu[i];
340                 if (cpu != NULL) {
341                     CPUState *cs = CPU(cpu);
342                     /* IPI can be either cleared or set by the write.  */
343                     if (newval & (1 << (i + 8))) {
344                         cpu_interrupt(cs, CPU_INTERRUPT_SMP);
345                     } else {
346                         cpu_reset_interrupt(cs, CPU_INTERRUPT_SMP);
347                     }
348 
349                     /* ITI can only be cleared by the write.  */
350                     if ((newval & (1 << (i + 4))) == 0) {
351                         cpu_reset_interrupt(cs, CPU_INTERRUPT_TIMER);
352                     }
353                 }
354             }
355         }
356         break;
357 
358     case 0x00c0:
359         /* MPD: Memory Presence Detect Register.  */
360         break;
361 
362     case 0x0100: /* AAR0 */
363     case 0x0140: /* AAR1 */
364     case 0x0180: /* AAR2 */
365     case 0x01c0: /* AAR3 */
366         /* AAR: Array Address Register.  */
367         /* All sorts of information about DRAM.  */
368         break;
369 
370     case 0x0200: /* DIM0 */
371         /* DIM: Device Interrupt Mask Register, CPU0.  */
372         s->cchip.dim[0] = val;
373         cpu_irq_change(s->cchip.cpu[0], val & s->cchip.drir);
374         break;
375     case 0x0240: /* DIM1 */
376         /* DIM: Device Interrupt Mask Register, CPU1.  */
377         s->cchip.dim[0] = val;
378         cpu_irq_change(s->cchip.cpu[1], val & s->cchip.drir);
379         break;
380 
381     case 0x0280: /* DIR0 (RO) */
382     case 0x02c0: /* DIR1 (RO) */
383     case 0x0300: /* DRIR (RO) */
384         break;
385 
386     case 0x0340:
387         /* PRBEN: Probe Enable Register.  */
388         break;
389 
390     case 0x0380: /* IIC0 */
391         s->cchip.iic[0] = val & 0xffffff;
392         break;
393     case 0x03c0: /* IIC1 */
394         s->cchip.iic[1] = val & 0xffffff;
395         break;
396 
397     case 0x0400: /* MPR0 */
398     case 0x0440: /* MPR1 */
399     case 0x0480: /* MPR2 */
400     case 0x04c0: /* MPR3 */
401         /* MPR: Memory Programming Register.  */
402         break;
403 
404     case 0x0580:
405         /* TTR: TIGbus Timing Register.  */
406         /* All sorts of stuff related to interrupt delivery timings.  */
407         break;
408     case 0x05c0:
409         /* TDR: TIGbug Device Timing Register.  */
410         break;
411 
412     case 0x0600:
413         /* DIM2: Device Interrupt Mask Register, CPU2.  */
414         s->cchip.dim[2] = val;
415         cpu_irq_change(s->cchip.cpu[2], val & s->cchip.drir);
416         break;
417     case 0x0640:
418         /* DIM3: Device Interrupt Mask Register, CPU3.  */
419         s->cchip.dim[3] = val;
420         cpu_irq_change(s->cchip.cpu[3], val & s->cchip.drir);
421         break;
422 
423     case 0x0680: /* DIR2 (RO) */
424     case 0x06c0: /* DIR3 (RO) */
425         break;
426 
427     case 0x0700: /* IIC2 */
428         s->cchip.iic[2] = val & 0xffffff;
429         break;
430     case 0x0740: /* IIC3 */
431         s->cchip.iic[3] = val & 0xffffff;
432         break;
433 
434     case 0x0780:
435         /* PWR: Power Management Control.   */
436         break;
437 
438     case 0x0c00: /* CMONCTLA */
439     case 0x0c40: /* CMONCTLB */
440     case 0x0c80: /* CMONCNT01 */
441     case 0x0cc0: /* CMONCNT23 */
442         break;
443 
444     default:
445         cpu_unassigned_access(current_cpu, addr, true, false, 0, size);
446         return;
447     }
448 }
449 
450 static void dchip_write(void *opaque, hwaddr addr,
451                         uint64_t val, unsigned size)
452 {
453     /* Skip this.  It's all related to DRAM timing and setup.  */
454 }
455 
456 static void pchip_write(void *opaque, hwaddr addr,
457                         uint64_t val, unsigned size)
458 {
459     TyphoonState *s = opaque;
460     uint64_t oldval;
461 
462     switch (addr) {
463     case 0x0000:
464         /* WSBA0: Window Space Base Address Register.  */
465         s->pchip.win[0].wba = val & 0xfff00003u;
466         break;
467     case 0x0040:
468         /* WSBA1 */
469         s->pchip.win[1].wba = val & 0xfff00003u;
470         break;
471     case 0x0080:
472         /* WSBA2 */
473         s->pchip.win[2].wba = val & 0xfff00003u;
474         break;
475     case 0x00c0:
476         /* WSBA3 */
477         s->pchip.win[3].wba = (val & 0x80fff00001ull) | 2;
478         break;
479 
480     case 0x0100:
481         /* WSM0: Window Space Mask Register.  */
482         s->pchip.win[0].wsm = val & 0xfff00000u;
483         break;
484     case 0x0140:
485         /* WSM1 */
486         s->pchip.win[1].wsm = val & 0xfff00000u;
487         break;
488     case 0x0180:
489         /* WSM2 */
490         s->pchip.win[2].wsm = val & 0xfff00000u;
491         break;
492     case 0x01c0:
493         /* WSM3 */
494         s->pchip.win[3].wsm = val & 0xfff00000u;
495         break;
496 
497     case 0x0200:
498         /* TBA0: Translated Base Address Register.  */
499         s->pchip.win[0].tba = val & 0x7fffffc00ull;
500         break;
501     case 0x0240:
502         /* TBA1 */
503         s->pchip.win[1].tba = val & 0x7fffffc00ull;
504         break;
505     case 0x0280:
506         /* TBA2 */
507         s->pchip.win[2].tba = val & 0x7fffffc00ull;
508         break;
509     case 0x02c0:
510         /* TBA3 */
511         s->pchip.win[3].tba = val & 0x7fffffc00ull;
512         break;
513 
514     case 0x0300:
515         /* PCTL: Pchip Control Register.  */
516         oldval = s->pchip.ctl;
517         oldval &= ~0x00001cff0fc7ffull;       /* RW fields */
518         oldval |= val & 0x00001cff0fc7ffull;
519         s->pchip.ctl = oldval;
520         break;
521 
522     case 0x0340:
523         /* PLAT: Pchip Master Latency Register.  */
524         break;
525     case 0x03c0:
526         /* PERROR: Pchip Error Register.  */
527         break;
528     case 0x0400:
529         /* PERRMASK: Pchip Error Mask Register.  */
530         break;
531     case 0x0440:
532         /* PERRSET: Pchip Error Set Register.  */
533         break;
534 
535     case 0x0480:
536         /* TLBIV: Translation Buffer Invalidate Virtual Register.  */
537         break;
538 
539     case 0x04c0:
540         /* TLBIA: Translation Buffer Invalidate All Register (WO).  */
541         break;
542 
543     case 0x0500:
544         /* PMONCTL */
545     case 0x0540:
546         /* PMONCNT */
547     case 0x0800:
548         /* SPRST */
549         break;
550 
551     default:
552         cpu_unassigned_access(current_cpu, addr, true, false, 0, size);
553         return;
554     }
555 }
556 
557 static const MemoryRegionOps cchip_ops = {
558     .read = cchip_read,
559     .write = cchip_write,
560     .endianness = DEVICE_LITTLE_ENDIAN,
561     .valid = {
562         .min_access_size = 8,
563         .max_access_size = 8,
564     },
565     .impl = {
566         .min_access_size = 8,
567         .max_access_size = 8,
568     },
569 };
570 
571 static const MemoryRegionOps dchip_ops = {
572     .read = dchip_read,
573     .write = dchip_write,
574     .endianness = DEVICE_LITTLE_ENDIAN,
575     .valid = {
576         .min_access_size = 8,
577         .max_access_size = 8,
578     },
579     .impl = {
580         .min_access_size = 8,
581         .max_access_size = 8,
582     },
583 };
584 
585 static const MemoryRegionOps pchip_ops = {
586     .read = pchip_read,
587     .write = pchip_write,
588     .endianness = DEVICE_LITTLE_ENDIAN,
589     .valid = {
590         .min_access_size = 8,
591         .max_access_size = 8,
592     },
593     .impl = {
594         .min_access_size = 8,
595         .max_access_size = 8,
596     },
597 };
598 
599 /* A subroutine of typhoon_translate_iommu that builds an IOMMUTLBEntry
600    using the given translated address and mask.  */
601 static bool make_iommu_tlbe(hwaddr taddr, hwaddr mask, IOMMUTLBEntry *ret)
602 {
603     *ret = (IOMMUTLBEntry) {
604         .target_as = &address_space_memory,
605         .translated_addr = taddr,
606         .addr_mask = mask,
607         .perm = IOMMU_RW,
608     };
609     return true;
610 }
611 
612 /* A subroutine of typhoon_translate_iommu that handles scatter-gather
613    translation, given the address of the PTE.  */
614 static bool pte_translate(hwaddr pte_addr, IOMMUTLBEntry *ret)
615 {
616     uint64_t pte = ldq_phys(&address_space_memory, pte_addr);
617 
618     /* Check valid bit.  */
619     if ((pte & 1) == 0) {
620         return false;
621     }
622 
623     return make_iommu_tlbe((pte & 0x3ffffe) << 12, 0x1fff, ret);
624 }
625 
626 /* A subroutine of typhoon_translate_iommu that handles one of the
627    four single-address-cycle translation windows.  */
628 static bool window_translate(TyphoonWindow *win, hwaddr addr,
629                              IOMMUTLBEntry *ret)
630 {
631     uint32_t wba = win->wba;
632     uint64_t wsm = win->wsm;
633     uint64_t tba = win->tba;
634     uint64_t wsm_ext = wsm | 0xfffff;
635 
636     /* Check for window disabled.  */
637     if ((wba & 1) == 0) {
638         return false;
639     }
640 
641     /* Check for window hit.  */
642     if ((addr & ~wsm_ext) != (wba & 0xfff00000u)) {
643         return false;
644     }
645 
646     if (wba & 2) {
647         /* Scatter-gather translation.  */
648         hwaddr pte_addr;
649 
650         /* See table 10-6, Generating PTE address for PCI DMA Address.  */
651         pte_addr  = tba & ~(wsm >> 10);
652         pte_addr |= (addr & (wsm | 0xfe000)) >> 10;
653         return pte_translate(pte_addr, ret);
654     } else {
655 	/* Direct-mapped translation.  */
656 	return make_iommu_tlbe(tba & ~wsm_ext, wsm_ext, ret);
657     }
658 }
659 
660 /* Handle PCI-to-system address translation.  */
661 /* TODO: A translation failure here ought to set PCI error codes on the
662    Pchip and generate a machine check interrupt.  */
663 static IOMMUTLBEntry typhoon_translate_iommu(MemoryRegion *iommu, hwaddr addr)
664 {
665     TyphoonPchip *pchip = container_of(iommu, TyphoonPchip, iommu);
666     IOMMUTLBEntry ret;
667     int i;
668 
669     if (addr <= 0xffffffffu) {
670         /* Single-address cycle.  */
671 
672         /* Check for the Window Hole, inhibiting matching.  */
673         if ((pchip->ctl & 0x20)
674             && addr >= 0x80000
675             && addr <= 0xfffff) {
676             goto failure;
677         }
678 
679         /* Check the first three windows.  */
680         for (i = 0; i < 3; ++i) {
681             if (window_translate(&pchip->win[i], addr, &ret)) {
682                 goto success;
683             }
684         }
685 
686         /* Check the fourth window for DAC disable.  */
687         if ((pchip->win[3].wba & 0x80000000000ull) == 0
688 	    && window_translate(&pchip->win[3], addr, &ret)) {
689             goto success;
690         }
691     } else {
692         /* Double-address cycle.  */
693 
694         if (addr >= 0x10000000000ull && addr < 0x20000000000ull) {
695             /* Check for the DMA monster window.  */
696             if (pchip->ctl & 0x40) {
697                 /* See 10.1.4.4; in particular <39:35> is ignored.  */
698                 make_iommu_tlbe(0, 0x007ffffffffull, &ret);
699 		goto success;
700             }
701         }
702 
703         if (addr >= 0x80000000000ull && addr <= 0xfffffffffffull) {
704             /* Check the fourth window for DAC enable and window enable.  */
705             if ((pchip->win[3].wba & 0x80000000001ull) == 0x80000000001ull) {
706                 uint64_t pte_addr;
707 
708                 pte_addr  = pchip->win[3].tba & 0x7ffc00000ull;
709                 pte_addr |= (addr & 0xffffe000u) >> 10;
710                 if (pte_translate(pte_addr, &ret)) {
711 			goto success;
712 		}
713             }
714         }
715     }
716 
717  failure:
718     ret = (IOMMUTLBEntry) { .perm = IOMMU_NONE };
719  success:
720     return ret;
721 }
722 
723 static const MemoryRegionIOMMUOps typhoon_iommu_ops = {
724     .translate = typhoon_translate_iommu,
725 };
726 
727 static AddressSpace *typhoon_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
728 {
729     TyphoonState *s = opaque;
730     return &s->pchip.iommu_as;
731 }
732 
733 static void typhoon_set_irq(void *opaque, int irq, int level)
734 {
735     TyphoonState *s = opaque;
736     uint64_t drir;
737     int i;
738 
739     /* Set/Reset the bit in CCHIP.DRIR based on IRQ+LEVEL.  */
740     drir = s->cchip.drir;
741     if (level) {
742         drir |= 1ull << irq;
743     } else {
744         drir &= ~(1ull << irq);
745     }
746     s->cchip.drir = drir;
747 
748     for (i = 0; i < 4; ++i) {
749         cpu_irq_change(s->cchip.cpu[i], s->cchip.dim[i] & drir);
750     }
751 }
752 
753 static void typhoon_set_isa_irq(void *opaque, int irq, int level)
754 {
755     typhoon_set_irq(opaque, 55, level);
756 }
757 
758 static void typhoon_set_timer_irq(void *opaque, int irq, int level)
759 {
760     TyphoonState *s = opaque;
761     int i;
762 
763     /* Thankfully, the mc146818rtc code doesn't track the IRQ state,
764        and so we don't have to worry about missing interrupts just
765        because we never actually ACK the interrupt.  Just ignore any
766        case of the interrupt level going low.  */
767     if (level == 0) {
768         return;
769     }
770 
771     /* Deliver the interrupt to each CPU, considering each CPU's IIC.  */
772     for (i = 0; i < 4; ++i) {
773         AlphaCPU *cpu = s->cchip.cpu[i];
774         if (cpu != NULL) {
775             uint32_t iic = s->cchip.iic[i];
776 
777             /* ??? The verbage in Section 10.2.2.10 isn't 100% clear.
778                Bit 24 is the OverFlow bit, RO, and set when the count
779                decrements past 0.  When is OF cleared?  My guess is that
780                OF is actually cleared when the IIC is written, and that
781                the ICNT field always decrements.  At least, that's an
782                interpretation that makes sense, and "allows the CPU to
783                determine exactly how mant interval timer ticks were
784                skipped".  At least within the next 4M ticks...  */
785 
786             iic = ((iic - 1) & 0x1ffffff) | (iic & 0x1000000);
787             s->cchip.iic[i] = iic;
788 
789             if (iic & 0x1000000) {
790                 /* Set the ITI bit for this cpu.  */
791                 s->cchip.misc |= 1 << (i + 4);
792                 /* And signal the interrupt.  */
793                 cpu_interrupt(CPU(cpu), CPU_INTERRUPT_TIMER);
794             }
795         }
796     }
797 }
798 
799 static void typhoon_alarm_timer(void *opaque)
800 {
801     TyphoonState *s = (TyphoonState *)((uintptr_t)opaque & ~3);
802     int cpu = (uintptr_t)opaque & 3;
803 
804     /* Set the ITI bit for this cpu.  */
805     s->cchip.misc |= 1 << (cpu + 4);
806     cpu_interrupt(CPU(s->cchip.cpu[cpu]), CPU_INTERRUPT_TIMER);
807 }
808 
809 PCIBus *typhoon_init(ram_addr_t ram_size, ISABus **isa_bus,
810                      qemu_irq *p_rtc_irq,
811                      AlphaCPU *cpus[4], pci_map_irq_fn sys_map_irq)
812 {
813     const uint64_t MB = 1024 * 1024;
814     const uint64_t GB = 1024 * MB;
815     MemoryRegion *addr_space = get_system_memory();
816     DeviceState *dev;
817     TyphoonState *s;
818     PCIHostState *phb;
819     PCIBus *b;
820     int i;
821 
822     dev = qdev_create(NULL, TYPE_TYPHOON_PCI_HOST_BRIDGE);
823     qdev_init_nofail(dev);
824 
825     s = TYPHOON_PCI_HOST_BRIDGE(dev);
826     phb = PCI_HOST_BRIDGE(dev);
827 
828     s->cchip.misc = 0x800000000ull; /* Revision: Typhoon.  */
829     s->pchip.win[3].wba = 2;        /* Window 3 SG always enabled. */
830 
831     /* Remember the CPUs so that we can deliver interrupts to them.  */
832     for (i = 0; i < 4; i++) {
833         AlphaCPU *cpu = cpus[i];
834         s->cchip.cpu[i] = cpu;
835         if (cpu != NULL) {
836             cpu->alarm_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
837                                                  typhoon_alarm_timer,
838                                                  (void *)((uintptr_t)s + i));
839         }
840     }
841 
842     *p_rtc_irq = *qemu_allocate_irqs(typhoon_set_timer_irq, s, 1);
843 
844     /* Main memory region, 0x00.0000.0000.  Real hardware supports 32GB,
845        but the address space hole reserved at this point is 8TB.  */
846     memory_region_init_ram(&s->ram_region, OBJECT(s), "ram", ram_size);
847     vmstate_register_ram_global(&s->ram_region);
848     memory_region_add_subregion(addr_space, 0, &s->ram_region);
849 
850     /* TIGbus, 0x801.0000.0000, 1GB.  */
851     /* ??? The TIGbus is used for delivering interrupts, and access to
852        the flash ROM.  I'm not sure that we need to implement it at all.  */
853 
854     /* Pchip0 CSRs, 0x801.8000.0000, 256MB.  */
855     memory_region_init_io(&s->pchip.region, OBJECT(s), &pchip_ops, s, "pchip0",
856                           256*MB);
857     memory_region_add_subregion(addr_space, 0x80180000000ULL,
858                                 &s->pchip.region);
859 
860     /* Cchip CSRs, 0x801.A000.0000, 256MB.  */
861     memory_region_init_io(&s->cchip.region, OBJECT(s), &cchip_ops, s, "cchip0",
862                           256*MB);
863     memory_region_add_subregion(addr_space, 0x801a0000000ULL,
864                                 &s->cchip.region);
865 
866     /* Dchip CSRs, 0x801.B000.0000, 256MB.  */
867     memory_region_init_io(&s->dchip_region, OBJECT(s), &dchip_ops, s, "dchip0",
868                           256*MB);
869     memory_region_add_subregion(addr_space, 0x801b0000000ULL,
870                                 &s->dchip_region);
871 
872     /* Pchip0 PCI memory, 0x800.0000.0000, 4GB.  */
873     memory_region_init(&s->pchip.reg_mem, OBJECT(s), "pci0-mem", 4*GB);
874     memory_region_add_subregion(addr_space, 0x80000000000ULL,
875                                 &s->pchip.reg_mem);
876 
877     /* Pchip0 PCI I/O, 0x801.FC00.0000, 32MB.  */
878     memory_region_init_io(&s->pchip.reg_io, OBJECT(s), &alpha_pci_ignore_ops,
879                           NULL, "pci0-io", 32*MB);
880     memory_region_add_subregion(addr_space, 0x801fc000000ULL,
881                                 &s->pchip.reg_io);
882 
883     b = pci_register_bus(dev, "pci",
884                          typhoon_set_irq, sys_map_irq, s,
885                          &s->pchip.reg_mem, &s->pchip.reg_io,
886                          0, 64, TYPE_PCI_BUS);
887     phb->bus = b;
888 
889     /* Host memory as seen from the PCI side, via the IOMMU.  */
890     memory_region_init_iommu(&s->pchip.iommu, OBJECT(s), &typhoon_iommu_ops,
891                              "iommu-typhoon", UINT64_MAX);
892     address_space_init(&s->pchip.iommu_as, &s->pchip.iommu, "pchip0-pci");
893     pci_setup_iommu(b, typhoon_pci_dma_iommu, s);
894 
895     /* Pchip0 PCI special/interrupt acknowledge, 0x801.F800.0000, 64MB.  */
896     memory_region_init_io(&s->pchip.reg_iack, OBJECT(s), &alpha_pci_iack_ops,
897                           b, "pci0-iack", 64*MB);
898     memory_region_add_subregion(addr_space, 0x801f8000000ULL,
899                                 &s->pchip.reg_iack);
900 
901     /* Pchip0 PCI configuration, 0x801.FE00.0000, 16MB.  */
902     memory_region_init_io(&s->pchip.reg_conf, OBJECT(s), &alpha_pci_conf1_ops,
903                           b, "pci0-conf", 16*MB);
904     memory_region_add_subregion(addr_space, 0x801fe000000ULL,
905                                 &s->pchip.reg_conf);
906 
907     /* For the record, these are the mappings for the second PCI bus.
908        We can get away with not implementing them because we indicate
909        via the Cchip.CSC<PIP> bit that Pchip1 is not present.  */
910     /* Pchip1 PCI memory, 0x802.0000.0000, 4GB.  */
911     /* Pchip1 CSRs, 0x802.8000.0000, 256MB.  */
912     /* Pchip1 PCI special/interrupt acknowledge, 0x802.F800.0000, 64MB.  */
913     /* Pchip1 PCI I/O, 0x802.FC00.0000, 32MB.  */
914     /* Pchip1 PCI configuration, 0x802.FE00.0000, 16MB.  */
915 
916     /* Init the ISA bus.  */
917     /* ??? Technically there should be a cy82c693ub pci-isa bridge.  */
918     {
919         qemu_irq isa_pci_irq, *isa_irqs;
920 
921         *isa_bus = isa_bus_new(NULL, &s->pchip.reg_io);
922         isa_pci_irq = *qemu_allocate_irqs(typhoon_set_isa_irq, s, 1);
923         isa_irqs = i8259_init(*isa_bus, isa_pci_irq);
924         isa_bus_irqs(*isa_bus, isa_irqs);
925     }
926 
927     return b;
928 }
929 
930 static int typhoon_pcihost_init(SysBusDevice *dev)
931 {
932     return 0;
933 }
934 
935 static void typhoon_pcihost_class_init(ObjectClass *klass, void *data)
936 {
937     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
938 
939     k->init = typhoon_pcihost_init;
940 }
941 
942 static const TypeInfo typhoon_pcihost_info = {
943     .name          = TYPE_TYPHOON_PCI_HOST_BRIDGE,
944     .parent        = TYPE_PCI_HOST_BRIDGE,
945     .instance_size = sizeof(TyphoonState),
946     .class_init    = typhoon_pcihost_class_init,
947 };
948 
949 static void typhoon_register_types(void)
950 {
951     type_register_static(&typhoon_pcihost_info);
952 }
953 
954 type_init(typhoon_register_types)
955