xref: /openbmc/qemu/hw/ppc/pnv_lpc.c (revision 8f3cd250)
1 /*
2  * QEMU PowerPC PowerNV LPC controller
3  *
4  * Copyright (c) 2016, IBM Corporation.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "sysemu/sysemu.h"
22 #include "target/ppc/cpu.h"
23 #include "qapi/error.h"
24 #include "qemu/log.h"
25 #include "hw/isa/isa.h"
26 
27 #include "hw/ppc/pnv.h"
28 #include "hw/ppc/pnv_lpc.h"
29 #include "hw/ppc/pnv_xscom.h"
30 #include "hw/ppc/fdt.h"
31 
32 #include <libfdt.h>
33 
34 enum {
35     ECCB_CTL    = 0,
36     ECCB_RESET  = 1,
37     ECCB_STAT   = 2,
38     ECCB_DATA   = 3,
39 };
40 
41 /* OPB Master LS registers */
42 #define OPB_MASTER_LS_IRQ_STAT  0x50
43 #define   OPB_MASTER_IRQ_LPC            0x00000800
44 #define OPB_MASTER_LS_IRQ_MASK  0x54
45 #define OPB_MASTER_LS_IRQ_POL   0x58
46 #define OPB_MASTER_LS_IRQ_INPUT 0x5c
47 
48 /* LPC HC registers */
49 #define LPC_HC_FW_SEG_IDSEL     0x24
50 #define LPC_HC_FW_RD_ACC_SIZE   0x28
51 #define   LPC_HC_FW_RD_1B               0x00000000
52 #define   LPC_HC_FW_RD_2B               0x01000000
53 #define   LPC_HC_FW_RD_4B               0x02000000
54 #define   LPC_HC_FW_RD_16B              0x04000000
55 #define   LPC_HC_FW_RD_128B             0x07000000
56 #define LPC_HC_IRQSER_CTRL      0x30
57 #define   LPC_HC_IRQSER_EN              0x80000000
58 #define   LPC_HC_IRQSER_QMODE           0x40000000
59 #define   LPC_HC_IRQSER_START_MASK      0x03000000
60 #define   LPC_HC_IRQSER_START_4CLK      0x00000000
61 #define   LPC_HC_IRQSER_START_6CLK      0x01000000
62 #define   LPC_HC_IRQSER_START_8CLK      0x02000000
63 #define LPC_HC_IRQMASK          0x34    /* same bit defs as LPC_HC_IRQSTAT */
64 #define LPC_HC_IRQSTAT          0x38
65 #define   LPC_HC_IRQ_SERIRQ0            0x80000000 /* all bits down to ... */
66 #define   LPC_HC_IRQ_SERIRQ16           0x00008000 /* IRQ16=IOCHK#, IRQ2=SMI# */
67 #define   LPC_HC_IRQ_SERIRQ_ALL         0xffff8000
68 #define   LPC_HC_IRQ_LRESET             0x00000400
69 #define   LPC_HC_IRQ_SYNC_ABNORM_ERR    0x00000080
70 #define   LPC_HC_IRQ_SYNC_NORESP_ERR    0x00000040
71 #define   LPC_HC_IRQ_SYNC_NORM_ERR      0x00000020
72 #define   LPC_HC_IRQ_SYNC_TIMEOUT_ERR   0x00000010
73 #define   LPC_HC_IRQ_SYNC_TARG_TAR_ERR  0x00000008
74 #define   LPC_HC_IRQ_SYNC_BM_TAR_ERR    0x00000004
75 #define   LPC_HC_IRQ_SYNC_BM0_REQ       0x00000002
76 #define   LPC_HC_IRQ_SYNC_BM1_REQ       0x00000001
77 #define LPC_HC_ERROR_ADDRESS    0x40
78 
79 #define LPC_OPB_SIZE            0x100000000ull
80 
81 #define ISA_IO_SIZE             0x00010000
82 #define ISA_MEM_SIZE            0x10000000
83 #define ISA_FW_SIZE             0x10000000
84 #define LPC_IO_OPB_ADDR         0xd0010000
85 #define LPC_IO_OPB_SIZE         0x00010000
86 #define LPC_MEM_OPB_ADDR        0xe0010000
87 #define LPC_MEM_OPB_SIZE        0x10000000
88 #define LPC_FW_OPB_ADDR         0xf0000000
89 #define LPC_FW_OPB_SIZE         0x10000000
90 
91 #define LPC_OPB_REGS_OPB_ADDR   0xc0010000
92 #define LPC_OPB_REGS_OPB_SIZE   0x00002000
93 #define LPC_HC_REGS_OPB_ADDR    0xc0012000
94 #define LPC_HC_REGS_OPB_SIZE    0x00001000
95 
96 
97 static int pnv_lpc_dt_xscom(PnvXScomInterface *dev, void *fdt, int xscom_offset)
98 {
99     const char compat[] = "ibm,power8-lpc\0ibm,lpc";
100     char *name;
101     int offset;
102     uint32_t lpc_pcba = PNV_XSCOM_LPC_BASE;
103     uint32_t reg[] = {
104         cpu_to_be32(lpc_pcba),
105         cpu_to_be32(PNV_XSCOM_LPC_SIZE)
106     };
107 
108     name = g_strdup_printf("isa@%x", lpc_pcba);
109     offset = fdt_add_subnode(fdt, xscom_offset, name);
110     _FDT(offset);
111     g_free(name);
112 
113     _FDT((fdt_setprop(fdt, offset, "reg", reg, sizeof(reg))));
114     _FDT((fdt_setprop_cell(fdt, offset, "#address-cells", 2)));
115     _FDT((fdt_setprop_cell(fdt, offset, "#size-cells", 1)));
116     _FDT((fdt_setprop(fdt, offset, "compatible", compat, sizeof(compat))));
117     return 0;
118 }
119 
120 /*
121  * These read/write handlers of the OPB address space should be common
122  * with the P9 LPC Controller which uses direct MMIOs.
123  *
124  * TODO: rework to use address_space_stq() and address_space_ldq()
125  * instead.
126  */
127 static bool opb_read(PnvLpcController *lpc, uint32_t addr, uint8_t *data,
128                      int sz)
129 {
130     /* XXX Handle access size limits and FW read caching here */
131     return !address_space_rw(&lpc->opb_as, addr, MEMTXATTRS_UNSPECIFIED,
132                              data, sz, false);
133 }
134 
135 static bool opb_write(PnvLpcController *lpc, uint32_t addr, uint8_t *data,
136                       int sz)
137 {
138     /* XXX Handle access size limits here */
139     return !address_space_rw(&lpc->opb_as, addr, MEMTXATTRS_UNSPECIFIED,
140                              data, sz, true);
141 }
142 
143 #define ECCB_CTL_READ           PPC_BIT(15)
144 #define ECCB_CTL_SZ_LSH         (63 - 7)
145 #define ECCB_CTL_SZ_MASK        PPC_BITMASK(4, 7)
146 #define ECCB_CTL_ADDR_MASK      PPC_BITMASK(32, 63)
147 
148 #define ECCB_STAT_OP_DONE       PPC_BIT(52)
149 #define ECCB_STAT_OP_ERR        PPC_BIT(52)
150 #define ECCB_STAT_RD_DATA_LSH   (63 - 37)
151 #define ECCB_STAT_RD_DATA_MASK  (0xffffffff << ECCB_STAT_RD_DATA_LSH)
152 
153 static void pnv_lpc_do_eccb(PnvLpcController *lpc, uint64_t cmd)
154 {
155     /* XXX Check for magic bits at the top, addr size etc... */
156     unsigned int sz = (cmd & ECCB_CTL_SZ_MASK) >> ECCB_CTL_SZ_LSH;
157     uint32_t opb_addr = cmd & ECCB_CTL_ADDR_MASK;
158     uint8_t data[4];
159     bool success;
160 
161     if (cmd & ECCB_CTL_READ) {
162         success = opb_read(lpc, opb_addr, data, sz);
163         if (success) {
164             lpc->eccb_stat_reg = ECCB_STAT_OP_DONE |
165                     (((uint64_t)data[0]) << 24 |
166                      ((uint64_t)data[1]) << 16 |
167                      ((uint64_t)data[2]) <<  8 |
168                      ((uint64_t)data[3])) << ECCB_STAT_RD_DATA_LSH;
169         } else {
170             lpc->eccb_stat_reg = ECCB_STAT_OP_DONE |
171                     (0xffffffffull << ECCB_STAT_RD_DATA_LSH);
172         }
173     } else {
174         data[0] = lpc->eccb_data_reg >> 24;
175         data[1] = lpc->eccb_data_reg >> 16;
176         data[2] = lpc->eccb_data_reg >>  8;
177         data[3] = lpc->eccb_data_reg;
178 
179         success = opb_write(lpc, opb_addr, data, sz);
180         lpc->eccb_stat_reg = ECCB_STAT_OP_DONE;
181     }
182     /* XXX Which error bit (if any) to signal OPB error ? */
183 }
184 
185 static uint64_t pnv_lpc_xscom_read(void *opaque, hwaddr addr, unsigned size)
186 {
187     PnvLpcController *lpc = PNV_LPC(opaque);
188     uint32_t offset = addr >> 3;
189     uint64_t val = 0;
190 
191     switch (offset & 3) {
192     case ECCB_CTL:
193     case ECCB_RESET:
194         val = 0;
195         break;
196     case ECCB_STAT:
197         val = lpc->eccb_stat_reg;
198         lpc->eccb_stat_reg = 0;
199         break;
200     case ECCB_DATA:
201         val = ((uint64_t)lpc->eccb_data_reg) << 32;
202         break;
203     }
204     return val;
205 }
206 
207 static void pnv_lpc_xscom_write(void *opaque, hwaddr addr,
208                                 uint64_t val, unsigned size)
209 {
210     PnvLpcController *lpc = PNV_LPC(opaque);
211     uint32_t offset = addr >> 3;
212 
213     switch (offset & 3) {
214     case ECCB_CTL:
215         pnv_lpc_do_eccb(lpc, val);
216         break;
217     case ECCB_RESET:
218         /*  XXXX  */
219         break;
220     case ECCB_STAT:
221         break;
222     case ECCB_DATA:
223         lpc->eccb_data_reg = val >> 32;
224         break;
225     }
226 }
227 
228 static const MemoryRegionOps pnv_lpc_xscom_ops = {
229     .read = pnv_lpc_xscom_read,
230     .write = pnv_lpc_xscom_write,
231     .valid.min_access_size = 8,
232     .valid.max_access_size = 8,
233     .impl.min_access_size = 8,
234     .impl.max_access_size = 8,
235     .endianness = DEVICE_BIG_ENDIAN,
236 };
237 
238 static void pnv_lpc_eval_irqs(PnvLpcController *lpc)
239 {
240     bool lpc_to_opb_irq = false;
241 
242     /* Update LPC controller to OPB line */
243     if (lpc->lpc_hc_irqser_ctrl & LPC_HC_IRQSER_EN) {
244         uint32_t irqs;
245 
246         irqs = lpc->lpc_hc_irqstat & lpc->lpc_hc_irqmask;
247         lpc_to_opb_irq = (irqs != 0);
248     }
249 
250     /* We don't honor the polarity register, it's pointless and unused
251      * anyway
252      */
253     if (lpc_to_opb_irq) {
254         lpc->opb_irq_input |= OPB_MASTER_IRQ_LPC;
255     } else {
256         lpc->opb_irq_input &= ~OPB_MASTER_IRQ_LPC;
257     }
258 
259     /* Update OPB internal latch */
260     lpc->opb_irq_stat |= lpc->opb_irq_input & lpc->opb_irq_mask;
261 
262     /* Reflect the interrupt */
263     pnv_psi_irq_set(lpc->psi, PSIHB_IRQ_LPC_I2C, lpc->opb_irq_stat != 0);
264 }
265 
266 static uint64_t lpc_hc_read(void *opaque, hwaddr addr, unsigned size)
267 {
268     PnvLpcController *lpc = opaque;
269     uint64_t val = 0xfffffffffffffffful;
270 
271     switch (addr) {
272     case LPC_HC_FW_SEG_IDSEL:
273         val =  lpc->lpc_hc_fw_seg_idsel;
274         break;
275     case LPC_HC_FW_RD_ACC_SIZE:
276         val =  lpc->lpc_hc_fw_rd_acc_size;
277         break;
278     case LPC_HC_IRQSER_CTRL:
279         val =  lpc->lpc_hc_irqser_ctrl;
280         break;
281     case LPC_HC_IRQMASK:
282         val =  lpc->lpc_hc_irqmask;
283         break;
284     case LPC_HC_IRQSTAT:
285         val =  lpc->lpc_hc_irqstat;
286         break;
287     case LPC_HC_ERROR_ADDRESS:
288         val =  lpc->lpc_hc_error_addr;
289         break;
290     default:
291         qemu_log_mask(LOG_UNIMP, "LPC HC Unimplemented register: Ox%"
292                       HWADDR_PRIx "\n", addr);
293     }
294     return val;
295 }
296 
297 static void lpc_hc_write(void *opaque, hwaddr addr, uint64_t val,
298                          unsigned size)
299 {
300     PnvLpcController *lpc = opaque;
301 
302     /* XXX Filter out reserved bits */
303 
304     switch (addr) {
305     case LPC_HC_FW_SEG_IDSEL:
306         /* XXX Actually figure out how that works as this impact
307          * memory regions/aliases
308          */
309         lpc->lpc_hc_fw_seg_idsel = val;
310         break;
311     case LPC_HC_FW_RD_ACC_SIZE:
312         lpc->lpc_hc_fw_rd_acc_size = val;
313         break;
314     case LPC_HC_IRQSER_CTRL:
315         lpc->lpc_hc_irqser_ctrl = val;
316         pnv_lpc_eval_irqs(lpc);
317         break;
318     case LPC_HC_IRQMASK:
319         lpc->lpc_hc_irqmask = val;
320         pnv_lpc_eval_irqs(lpc);
321         break;
322     case LPC_HC_IRQSTAT:
323         lpc->lpc_hc_irqstat &= ~val;
324         pnv_lpc_eval_irqs(lpc);
325         break;
326     case LPC_HC_ERROR_ADDRESS:
327         break;
328     default:
329         qemu_log_mask(LOG_UNIMP, "LPC HC Unimplemented register: Ox%"
330                       HWADDR_PRIx "\n", addr);
331     }
332 }
333 
334 static const MemoryRegionOps lpc_hc_ops = {
335     .read = lpc_hc_read,
336     .write = lpc_hc_write,
337     .endianness = DEVICE_BIG_ENDIAN,
338     .valid = {
339         .min_access_size = 4,
340         .max_access_size = 4,
341     },
342     .impl = {
343         .min_access_size = 4,
344         .max_access_size = 4,
345     },
346 };
347 
348 static uint64_t opb_master_read(void *opaque, hwaddr addr, unsigned size)
349 {
350     PnvLpcController *lpc = opaque;
351     uint64_t val = 0xfffffffffffffffful;
352 
353     switch (addr) {
354     case OPB_MASTER_LS_IRQ_STAT:
355         val = lpc->opb_irq_stat;
356         break;
357     case OPB_MASTER_LS_IRQ_MASK:
358         val = lpc->opb_irq_mask;
359         break;
360     case OPB_MASTER_LS_IRQ_POL:
361         val = lpc->opb_irq_pol;
362         break;
363     case OPB_MASTER_LS_IRQ_INPUT:
364         val = lpc->opb_irq_input;
365         break;
366     default:
367         qemu_log_mask(LOG_UNIMP, "OPB MASTER Unimplemented register: Ox%"
368                       HWADDR_PRIx "\n", addr);
369     }
370 
371     return val;
372 }
373 
374 static void opb_master_write(void *opaque, hwaddr addr,
375                              uint64_t val, unsigned size)
376 {
377     PnvLpcController *lpc = opaque;
378 
379     switch (addr) {
380     case OPB_MASTER_LS_IRQ_STAT:
381         lpc->opb_irq_stat &= ~val;
382         pnv_lpc_eval_irqs(lpc);
383         break;
384     case OPB_MASTER_LS_IRQ_MASK:
385         lpc->opb_irq_mask = val;
386         pnv_lpc_eval_irqs(lpc);
387         break;
388     case OPB_MASTER_LS_IRQ_POL:
389         lpc->opb_irq_pol = val;
390         pnv_lpc_eval_irqs(lpc);
391         break;
392     case OPB_MASTER_LS_IRQ_INPUT:
393         /* Read only */
394         break;
395     default:
396         qemu_log_mask(LOG_UNIMP, "OPB MASTER Unimplemented register: Ox%"
397                       HWADDR_PRIx "\n", addr);
398     }
399 }
400 
401 static const MemoryRegionOps opb_master_ops = {
402     .read = opb_master_read,
403     .write = opb_master_write,
404     .endianness = DEVICE_BIG_ENDIAN,
405     .valid = {
406         .min_access_size = 4,
407         .max_access_size = 4,
408     },
409     .impl = {
410         .min_access_size = 4,
411         .max_access_size = 4,
412     },
413 };
414 
415 static void pnv_lpc_realize(DeviceState *dev, Error **errp)
416 {
417     PnvLpcController *lpc = PNV_LPC(dev);
418     Object *obj;
419     Error *error = NULL;
420 
421     /* Reg inits */
422     lpc->lpc_hc_fw_rd_acc_size = LPC_HC_FW_RD_4B;
423 
424     /* Create address space and backing MR for the OPB bus */
425     memory_region_init(&lpc->opb_mr, OBJECT(dev), "lpc-opb", 0x100000000ull);
426     address_space_init(&lpc->opb_as, &lpc->opb_mr, "lpc-opb");
427 
428     /* Create ISA IO and Mem space regions which are the root of
429      * the ISA bus (ie, ISA address spaces). We don't create a
430      * separate one for FW which we alias to memory.
431      */
432     memory_region_init(&lpc->isa_io, OBJECT(dev), "isa-io", ISA_IO_SIZE);
433     memory_region_init(&lpc->isa_mem, OBJECT(dev), "isa-mem", ISA_MEM_SIZE);
434     memory_region_init(&lpc->isa_fw, OBJECT(dev),  "isa-fw", ISA_FW_SIZE);
435 
436     /* Create windows from the OPB space to the ISA space */
437     memory_region_init_alias(&lpc->opb_isa_io, OBJECT(dev), "lpc-isa-io",
438                              &lpc->isa_io, 0, LPC_IO_OPB_SIZE);
439     memory_region_add_subregion(&lpc->opb_mr, LPC_IO_OPB_ADDR,
440                                 &lpc->opb_isa_io);
441     memory_region_init_alias(&lpc->opb_isa_mem, OBJECT(dev), "lpc-isa-mem",
442                              &lpc->isa_mem, 0, LPC_MEM_OPB_SIZE);
443     memory_region_add_subregion(&lpc->opb_mr, LPC_MEM_OPB_ADDR,
444                                 &lpc->opb_isa_mem);
445     memory_region_init_alias(&lpc->opb_isa_fw, OBJECT(dev), "lpc-isa-fw",
446                              &lpc->isa_fw, 0, LPC_FW_OPB_SIZE);
447     memory_region_add_subregion(&lpc->opb_mr, LPC_FW_OPB_ADDR,
448                                 &lpc->opb_isa_fw);
449 
450     /* Create MMIO regions for LPC HC and OPB registers */
451     memory_region_init_io(&lpc->opb_master_regs, OBJECT(dev), &opb_master_ops,
452                           lpc, "lpc-opb-master", LPC_OPB_REGS_OPB_SIZE);
453     memory_region_add_subregion(&lpc->opb_mr, LPC_OPB_REGS_OPB_ADDR,
454                                 &lpc->opb_master_regs);
455     memory_region_init_io(&lpc->lpc_hc_regs, OBJECT(dev), &lpc_hc_ops, lpc,
456                           "lpc-hc", LPC_HC_REGS_OPB_SIZE);
457     memory_region_add_subregion(&lpc->opb_mr, LPC_HC_REGS_OPB_ADDR,
458                                 &lpc->lpc_hc_regs);
459 
460     /* XScom region for LPC registers */
461     pnv_xscom_region_init(&lpc->xscom_regs, OBJECT(dev),
462                           &pnv_lpc_xscom_ops, lpc, "xscom-lpc",
463                           PNV_XSCOM_LPC_SIZE);
464 
465     /* get PSI object from chip */
466     obj = object_property_get_link(OBJECT(dev), "psi", &error);
467     if (!obj) {
468         error_setg(errp, "%s: required link 'psi' not found: %s",
469                    __func__, error_get_pretty(error));
470         return;
471     }
472     lpc->psi = PNV_PSI(obj);
473 }
474 
475 static void pnv_lpc_class_init(ObjectClass *klass, void *data)
476 {
477     DeviceClass *dc = DEVICE_CLASS(klass);
478     PnvXScomInterfaceClass *xdc = PNV_XSCOM_INTERFACE_CLASS(klass);
479 
480     xdc->dt_xscom = pnv_lpc_dt_xscom;
481 
482     dc->realize = pnv_lpc_realize;
483 }
484 
485 static const TypeInfo pnv_lpc_info = {
486     .name          = TYPE_PNV_LPC,
487     .parent        = TYPE_DEVICE,
488     .instance_size = sizeof(PnvLpcController),
489     .class_init    = pnv_lpc_class_init,
490     .interfaces = (InterfaceInfo[]) {
491         { TYPE_PNV_XSCOM_INTERFACE },
492         { }
493     }
494 };
495 
496 static void pnv_lpc_register_types(void)
497 {
498     type_register_static(&pnv_lpc_info);
499 }
500 
501 type_init(pnv_lpc_register_types)
502 
503 /* If we don't use the built-in LPC interrupt deserializer, we need
504  * to provide a set of qirqs for the ISA bus or things will go bad.
505  *
506  * Most machines using pre-Naples chips (without said deserializer)
507  * have a CPLD that will collect the SerIRQ and shoot them as a
508  * single level interrupt to the P8 chip. So let's setup a hook
509  * for doing just that.
510  */
511 static void pnv_lpc_isa_irq_handler_cpld(void *opaque, int n, int level)
512 {
513     PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
514     uint32_t old_state = pnv->cpld_irqstate;
515     PnvLpcController *lpc = PNV_LPC(opaque);
516 
517     if (level) {
518         pnv->cpld_irqstate |= 1u << n;
519     } else {
520         pnv->cpld_irqstate &= ~(1u << n);
521     }
522 
523     if (pnv->cpld_irqstate != old_state) {
524         pnv_psi_irq_set(lpc->psi, PSIHB_IRQ_EXTERNAL, pnv->cpld_irqstate != 0);
525     }
526 }
527 
528 static void pnv_lpc_isa_irq_handler(void *opaque, int n, int level)
529 {
530     PnvLpcController *lpc = PNV_LPC(opaque);
531 
532     /* The Naples HW latches the 1 levels, clearing is done by SW */
533     if (level) {
534         lpc->lpc_hc_irqstat |= LPC_HC_IRQ_SERIRQ0 >> n;
535         pnv_lpc_eval_irqs(lpc);
536     }
537 }
538 
539 ISABus *pnv_lpc_isa_create(PnvLpcController *lpc, bool use_cpld, Error **errp)
540 {
541     Error *local_err = NULL;
542     ISABus *isa_bus;
543     qemu_irq *irqs;
544     qemu_irq_handler handler;
545 
546     /* let isa_bus_new() create its own bridge on SysBus otherwise
547      * devices speficied on the command line won't find the bus and
548      * will fail to create.
549      */
550     isa_bus = isa_bus_new(NULL, &lpc->isa_mem, &lpc->isa_io, &local_err);
551     if (local_err) {
552         error_propagate(errp, local_err);
553         return NULL;
554     }
555 
556     /* Not all variants have a working serial irq decoder. If not,
557      * handling of LPC interrupts becomes a platform issue (some
558      * platforms have a CPLD to do it).
559      */
560     if (use_cpld) {
561         handler = pnv_lpc_isa_irq_handler_cpld;
562     } else {
563         handler = pnv_lpc_isa_irq_handler;
564     }
565 
566     irqs = qemu_allocate_irqs(handler, lpc, ISA_NUM_IRQS);
567 
568     isa_bus_irqs(isa_bus, irqs);
569     return isa_bus;
570 }
571