This patch includes scripts to create multiple yaml file for different
[kvmfornfv.git] / kernel / drivers / pci / hotplug / sgi_hotplug.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2005-2006 Silicon Graphics, Inc. All rights reserved.
7  *
8  * This work was based on the 2.4/2.6 kernel development by Dick Reigner.
9  * Work to add BIOS PROM support was completed by Mike Habeck.
10  */
11
12 #include <linux/acpi.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/pci.h>
17 #include <linux/pci_hotplug.h>
18 #include <linux/proc_fs.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21 #include <linux/mutex.h>
22
23 #include <asm/sn/addrs.h>
24 #include <asm/sn/geo.h>
25 #include <asm/sn/l1.h>
26 #include <asm/sn/module.h>
27 #include <asm/sn/pcibr_provider.h>
28 #include <asm/sn/pcibus_provider_defs.h>
29 #include <asm/sn/pcidev.h>
30 #include <asm/sn/sn_feature_sets.h>
31 #include <asm/sn/sn_sal.h>
32 #include <asm/sn/types.h>
33 #include <asm/sn/acpi.h>
34
35 #include "../pci.h"
36
37 MODULE_LICENSE("GPL");
38 MODULE_AUTHOR("SGI (prarit@sgi.com, dickie@sgi.com, habeck@sgi.com)");
39 MODULE_DESCRIPTION("SGI Altix Hot Plug PCI Controller Driver");
40
41
42 /* SAL call error codes. Keep in sync with prom header io/include/pcibr.h */
43 #define PCI_SLOT_ALREADY_UP             2       /* slot already up */
44 #define PCI_SLOT_ALREADY_DOWN           3       /* slot already down */
45 #define PCI_L1_ERR                      7       /* L1 console command error */
46 #define PCI_EMPTY_33MHZ                 15      /* empty 33 MHz bus */
47
48
49 #define PCIIO_ASIC_TYPE_TIOCA           4
50 #define PCI_L1_QSIZE                    128     /* our L1 message buffer size */
51 #define SN_MAX_HP_SLOTS                 32      /* max hotplug slots */
52 #define SN_SLOT_NAME_SIZE               33      /* size of name string */
53
54 /* internal list head */
55 static struct list_head sn_hp_list;
56
57 /* hotplug_slot struct's private pointer */
58 struct slot {
59         int device_num;
60         struct pci_bus *pci_bus;
61         /* this struct for glue internal only */
62         struct hotplug_slot *hotplug_slot;
63         struct list_head hp_list;
64         char physical_path[SN_SLOT_NAME_SIZE];
65 };
66
67 struct pcibr_slot_enable_resp {
68         int resp_sub_errno;
69         char resp_l1_msg[PCI_L1_QSIZE + 1];
70 };
71
72 struct pcibr_slot_disable_resp {
73         int resp_sub_errno;
74         char resp_l1_msg[PCI_L1_QSIZE + 1];
75 };
76
77 enum sn_pci_req_e {
78         PCI_REQ_SLOT_ELIGIBLE,
79         PCI_REQ_SLOT_DISABLE
80 };
81
82 static int enable_slot(struct hotplug_slot *slot);
83 static int disable_slot(struct hotplug_slot *slot);
84 static inline int get_power_status(struct hotplug_slot *slot, u8 *value);
85
86 static struct hotplug_slot_ops sn_hotplug_slot_ops = {
87         .enable_slot            = enable_slot,
88         .disable_slot           = disable_slot,
89         .get_power_status       = get_power_status,
90 };
91
92 static DEFINE_MUTEX(sn_hotplug_mutex);
93
94 static ssize_t path_show(struct pci_slot *pci_slot, char *buf)
95 {
96         int retval = -ENOENT;
97         struct slot *slot = pci_slot->hotplug->private;
98
99         if (!slot)
100                 return retval;
101
102         retval = sprintf (buf, "%s\n", slot->physical_path);
103         return retval;
104 }
105
106 static struct pci_slot_attribute sn_slot_path_attr = __ATTR_RO(path);
107
108 static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
109 {
110         struct pcibus_info *pcibus_info;
111         u16 busnum, segment, ioboard_type;
112
113         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
114
115         /* Check to see if this is a valid slot on 'pci_bus' */
116         if (!(pcibus_info->pbi_valid_devices & (1 << device)))
117                 return -EPERM;
118
119         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
120         busnum = pcibus_info->pbi_buscommon.bs_persist_busnum;
121         segment = pci_domain_nr(pci_bus) & 0xf;
122
123         /* Do not allow hotplug operations on base I/O cards */
124         if ((ioboard_type == L1_BRICKTYPE_IX ||
125              ioboard_type == L1_BRICKTYPE_IA) &&
126             (segment == 1 && busnum == 0 && device != 1))
127                 return -EPERM;
128
129         return 1;
130 }
131
132 static int sn_pci_bus_valid(struct pci_bus *pci_bus)
133 {
134         struct pcibus_info *pcibus_info;
135         u32 asic_type;
136         u16 ioboard_type;
137
138         /* Don't register slots hanging off the TIOCA bus */
139         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
140         asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
141         if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
142                 return -EPERM;
143
144         /* Only register slots in I/O Bricks that support hotplug */
145         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
146         switch (ioboard_type) {
147                 case L1_BRICKTYPE_IX:
148                 case L1_BRICKTYPE_PX:
149                 case L1_BRICKTYPE_IA:
150                 case L1_BRICKTYPE_PA:
151                 case L1_BOARDTYPE_PCIX3SLOT:
152                         return 1;
153                         break;
154                 default:
155                         return -EPERM;
156                         break;
157         }
158
159         return -EIO;
160 }
161
162 static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
163                                     struct pci_bus *pci_bus, int device,
164                                     char *name)
165 {
166         struct pcibus_info *pcibus_info;
167         struct slot *slot;
168
169         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
170
171         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
172         if (!slot)
173                 return -ENOMEM;
174         bss_hotplug_slot->private = slot;
175
176         slot->device_num = device;
177         slot->pci_bus = pci_bus;
178         sprintf(name, "%04x:%02x:%02x",
179                 pci_domain_nr(pci_bus),
180                 ((u16)pcibus_info->pbi_buscommon.bs_persist_busnum),
181                 device + 1);
182
183         sn_generate_path(pci_bus, slot->physical_path);
184
185         slot->hotplug_slot = bss_hotplug_slot;
186         list_add(&slot->hp_list, &sn_hp_list);
187
188         return 0;
189 }
190
191 static struct hotplug_slot *sn_hp_destroy(void)
192 {
193         struct slot *slot;
194         struct pci_slot *pci_slot;
195         struct hotplug_slot *bss_hotplug_slot = NULL;
196
197         list_for_each_entry(slot, &sn_hp_list, hp_list) {
198                 bss_hotplug_slot = slot->hotplug_slot;
199                 pci_slot = bss_hotplug_slot->pci_slot;
200                 list_del(&((struct slot *)bss_hotplug_slot->private)->
201                          hp_list);
202                 sysfs_remove_file(&pci_slot->kobj,
203                                   &sn_slot_path_attr.attr);
204                 break;
205         }
206         return bss_hotplug_slot;
207 }
208
209 static void sn_bus_free_data(struct pci_dev *dev)
210 {
211         struct pci_bus *subordinate_bus;
212         struct pci_dev *child;
213
214         /* Recursively clean up sn_irq_info structs */
215         if (dev->subordinate) {
216                 subordinate_bus = dev->subordinate;
217                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
218                         sn_bus_free_data(child);
219         }
220         /*
221          * Some drivers may use dma accesses during the
222          * driver remove function. We release the sysdata
223          * areas after the driver remove functions have
224          * been called.
225          */
226         sn_bus_store_sysdata(dev);
227         sn_pci_unfixup_slot(dev);
228 }
229
230 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
231                           int device_num, char **ssdt)
232 {
233         struct slot *slot = bss_hotplug_slot->private;
234         struct pcibus_info *pcibus_info;
235         struct pcibr_slot_enable_resp resp;
236         int rc;
237
238         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
239
240         /*
241          * Power-on and initialize the slot in the SN
242          * PCI infrastructure.
243          */
244         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp, ssdt);
245
246
247         if (rc == PCI_SLOT_ALREADY_UP) {
248                 dev_dbg(&slot->pci_bus->self->dev, "is already active\n");
249                 return 1; /* return 1 to user */
250         }
251
252         if (rc == PCI_L1_ERR) {
253                 dev_dbg(&slot->pci_bus->self->dev, "L1 failure %d with message: %s",
254                         resp.resp_sub_errno, resp.resp_l1_msg);
255                 return -EPERM;
256         }
257
258         if (rc) {
259                 dev_dbg(&slot->pci_bus->self->dev, "insert failed with error %d sub-error %d\n",
260                         rc, resp.resp_sub_errno);
261                 return -EIO;
262         }
263
264         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
265         pcibus_info->pbi_enabled_devices |= (1 << device_num);
266
267         return 0;
268 }
269
270 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
271                            int device_num, int action)
272 {
273         struct slot *slot = bss_hotplug_slot->private;
274         struct pcibus_info *pcibus_info;
275         struct pcibr_slot_disable_resp resp;
276         int rc;
277
278         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
279
280         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
281
282         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
283             (rc == PCI_SLOT_ALREADY_DOWN)) {
284                 dev_dbg(&slot->pci_bus->self->dev, "Slot %s already inactive\n", slot->physical_path);
285                 return 1; /* return 1 to user */
286         }
287
288         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
289                 dev_dbg(&slot->pci_bus->self->dev, "Cannot remove last 33MHz card\n");
290                 return -EPERM;
291         }
292
293         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
294                 dev_dbg(&slot->pci_bus->self->dev, "L1 failure %d with message \n%s\n",
295                         resp.resp_sub_errno, resp.resp_l1_msg);
296                 return -EPERM;
297         }
298
299         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
300                 dev_dbg(&slot->pci_bus->self->dev, "remove failed with error %d sub-error %d\n",
301                         rc, resp.resp_sub_errno);
302                 return -EIO;
303         }
304
305         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
306                 return 0;
307
308         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
309                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
310                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
311                 dev_dbg(&slot->pci_bus->self->dev, "remove successful\n");
312                 return 0;
313         }
314
315         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
316                 dev_dbg(&slot->pci_bus->self->dev,"remove failed rc = %d\n", rc);
317         }
318
319         return rc;
320 }
321
322 /*
323  * Power up and configure the slot via a SAL call to PROM.
324  * Scan slot (and any children), do any platform specific fixup,
325  * and find device driver.
326  */
327 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
328 {
329         struct slot *slot = bss_hotplug_slot->private;
330         struct pci_bus *new_bus = NULL;
331         struct pci_dev *dev;
332         int num_funcs;
333         int new_ppb = 0;
334         int rc;
335         char *ssdt = NULL;
336         void pcibios_fixup_device_resources(struct pci_dev *);
337
338         /* Serialize the Linux PCI infrastructure */
339         mutex_lock(&sn_hotplug_mutex);
340
341         /*
342          * Power-on and initialize the slot in the SN
343          * PCI infrastructure. Also, retrieve the ACPI SSDT
344          * table for the slot (if ACPI capable PROM).
345          */
346         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
347         if (rc) {
348                 mutex_unlock(&sn_hotplug_mutex);
349                 return rc;
350         }
351
352         if (ssdt)
353                 ssdt = __va(ssdt);
354         /* Add the new SSDT for the slot to the ACPI namespace */
355         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
356                 acpi_status ret;
357
358                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
359                 if (ACPI_FAILURE(ret)) {
360                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
361                                __func__, ret);
362                         /* try to continue on */
363                 }
364         }
365
366         num_funcs = pci_scan_slot(slot->pci_bus,
367                                   PCI_DEVFN(slot->device_num + 1, 0));
368         if (!num_funcs) {
369                 dev_dbg(&slot->pci_bus->self->dev, "no device in slot\n");
370                 mutex_unlock(&sn_hotplug_mutex);
371                 return -ENODEV;
372         }
373
374         /*
375          * Map SN resources for all functions on the card
376          * to the Linux PCI interface and tell the drivers
377          * about them.
378          */
379         list_for_each_entry(dev, &slot->pci_bus->devices, bus_list) {
380                 if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
381                         continue;
382
383                 /* Need to do slot fixup on PPB before fixup of children
384                  * (PPB's pcidev_info needs to be in pcidev_info list
385                  * before child's SN_PCIDEV_INFO() call to setup
386                  * pdi_host_pcidev_info).
387                  */
388                 pcibios_fixup_device_resources(dev);
389                 if (SN_ACPI_BASE_SUPPORT())
390                         sn_acpi_slot_fixup(dev);
391                 else
392                         sn_io_slot_fixup(dev);
393                 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
394                         pci_hp_add_bridge(dev);
395                         if (dev->subordinate) {
396                                 new_bus = dev->subordinate;
397                                 new_ppb = 1;
398                         }
399                 }
400         }
401
402         /*
403          * Add the slot's devices to the ACPI infrastructure */
404         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
405                 unsigned long long adr;
406                 struct acpi_device *pdevice;
407                 acpi_handle phandle;
408                 acpi_handle chandle = NULL;
409                 acpi_handle rethandle;
410                 acpi_status ret;
411
412                 phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
413
414                 if (acpi_bus_get_device(phandle, &pdevice)) {
415                         dev_dbg(&slot->pci_bus->self->dev, "no parent device, assuming NULL\n");
416                         pdevice = NULL;
417                 }
418
419                 acpi_scan_lock_acquire();
420                 /*
421                  * Walk the rootbus node's immediate children looking for
422                  * the slot's device node(s). There can be more than
423                  * one for multifunction devices.
424                  */
425                 for (;;) {
426                         rethandle = NULL;
427                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
428                                                    phandle, chandle,
429                                                    &rethandle);
430
431                         if (ret == AE_NOT_FOUND || rethandle == NULL)
432                                 break;
433
434                         chandle = rethandle;
435
436                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
437                                                     NULL, &adr);
438
439                         if (ACPI_SUCCESS(ret) &&
440                             (adr>>16) == (slot->device_num + 1)) {
441
442                                 ret = acpi_bus_scan(chandle);
443                                 if (ACPI_FAILURE(ret)) {
444                                         printk(KERN_ERR "%s: acpi_bus_scan failed (0x%x) for slot %d func %d\n",
445                                                __func__, ret, (int)(adr>>16),
446                                                (int)(adr&0xffff));
447                                         /* try to continue on */
448                                 }
449                         }
450                 }
451                 acpi_scan_lock_release();
452         }
453
454         pci_lock_rescan_remove();
455
456         /* Call the driver for the new device */
457         pci_bus_add_devices(slot->pci_bus);
458         /* Call the drivers for the new devices subordinate to PPB */
459         if (new_ppb)
460                 pci_bus_add_devices(new_bus);
461
462         pci_unlock_rescan_remove();
463         mutex_unlock(&sn_hotplug_mutex);
464
465         if (rc == 0)
466                 dev_dbg(&slot->pci_bus->self->dev, "insert operation successful\n");
467         else
468                 dev_dbg(&slot->pci_bus->self->dev, "insert operation failed rc = %d\n", rc);
469
470         return rc;
471 }
472
473 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
474 {
475         struct slot *slot = bss_hotplug_slot->private;
476         struct pci_dev *dev, *temp;
477         int rc;
478         acpi_handle ssdt_hdl = NULL;
479
480         /* Acquire update access to the bus */
481         mutex_lock(&sn_hotplug_mutex);
482
483         /* is it okay to bring this slot down? */
484         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
485                              PCI_REQ_SLOT_ELIGIBLE);
486         if (rc)
487                 goto leaving;
488
489         /* free the ACPI resources for the slot */
490         if (SN_ACPI_BASE_SUPPORT() &&
491             PCI_CONTROLLER(slot->pci_bus)->companion) {
492                 unsigned long long adr;
493                 struct acpi_device *device;
494                 acpi_handle phandle;
495                 acpi_handle chandle = NULL;
496                 acpi_handle rethandle;
497                 acpi_status ret;
498
499                 /* Get the rootbus node pointer */
500                 phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
501
502                 acpi_scan_lock_acquire();
503                 /*
504                  * Walk the rootbus node's immediate children looking for
505                  * the slot's device node(s). There can be more than
506                  * one for multifunction devices.
507                  */
508                 for (;;) {
509                         rethandle = NULL;
510                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
511                                                    phandle, chandle,
512                                                    &rethandle);
513
514                         if (ret == AE_NOT_FOUND || rethandle == NULL)
515                                 break;
516
517                         chandle = rethandle;
518
519                         ret = acpi_evaluate_integer(chandle,
520                                                     METHOD_NAME__ADR,
521                                                     NULL, &adr);
522                         if (ACPI_SUCCESS(ret) &&
523                             (adr>>16) == (slot->device_num + 1)) {
524                                 /* retain the owner id */
525                                 ssdt_hdl = chandle;
526
527                                 ret = acpi_bus_get_device(chandle,
528                                                           &device);
529                                 if (ACPI_SUCCESS(ret))
530                                         acpi_bus_trim(device);
531                         }
532                 }
533                 acpi_scan_lock_release();
534         }
535
536         pci_lock_rescan_remove();
537         /* Free the SN resources assigned to the Linux device.*/
538         list_for_each_entry_safe(dev, temp, &slot->pci_bus->devices, bus_list) {
539                 if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
540                         continue;
541
542                 pci_dev_get(dev);
543                 sn_bus_free_data(dev);
544                 pci_stop_and_remove_bus_device(dev);
545                 pci_dev_put(dev);
546         }
547         pci_unlock_rescan_remove();
548
549         /* Remove the SSDT for the slot from the ACPI namespace */
550         if (SN_ACPI_BASE_SUPPORT() && ssdt_hdl) {
551                 acpi_status ret;
552                 ret = acpi_unload_parent_table(ssdt_hdl);
553                 if (ACPI_FAILURE(ret)) {
554                         acpi_handle_err(ssdt_hdl,
555                                         "%s: acpi_unload_parent_table failed (0x%x)\n",
556                                         __func__, ret);
557                         /* try to continue on */
558                 }
559         }
560
561         /* free the collected sysdata pointers */
562         sn_bus_free_sysdata();
563
564         /* Deactivate slot */
565         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
566                              PCI_REQ_SLOT_DISABLE);
567  leaving:
568         /* Release the bus lock */
569         mutex_unlock(&sn_hotplug_mutex);
570
571         return rc;
572 }
573
574 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
575                                    u8 *value)
576 {
577         struct slot *slot = bss_hotplug_slot->private;
578         struct pcibus_info *pcibus_info;
579         u32 power;
580
581         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
582         mutex_lock(&sn_hotplug_mutex);
583         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
584         *value = power ? 1 : 0;
585         mutex_unlock(&sn_hotplug_mutex);
586         return 0;
587 }
588
589 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
590 {
591         kfree(bss_hotplug_slot->info);
592         kfree(bss_hotplug_slot->private);
593         kfree(bss_hotplug_slot);
594 }
595
596 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
597 {
598         int device;
599         struct pci_slot *pci_slot;
600         struct hotplug_slot *bss_hotplug_slot;
601         char name[SN_SLOT_NAME_SIZE];
602         int rc = 0;
603
604         /*
605          * Currently only four devices are supported,
606          * in the future there maybe more -- up to 32.
607          */
608
609         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
610                 if (sn_pci_slot_valid(pci_bus, device) != 1)
611                         continue;
612
613                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
614                                            GFP_KERNEL);
615                 if (!bss_hotplug_slot) {
616                         rc = -ENOMEM;
617                         goto alloc_err;
618                 }
619
620                 bss_hotplug_slot->info =
621                         kzalloc(sizeof(struct hotplug_slot_info),
622                                 GFP_KERNEL);
623                 if (!bss_hotplug_slot->info) {
624                         rc = -ENOMEM;
625                         goto alloc_err;
626                 }
627
628                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
629                                              pci_bus, device, name)) {
630                         rc = -ENOMEM;
631                         goto alloc_err;
632                 }
633                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
634                 bss_hotplug_slot->release = &sn_release_slot;
635
636                 rc = pci_hp_register(bss_hotplug_slot, pci_bus, device, name);
637                 if (rc)
638                         goto register_err;
639
640                 pci_slot = bss_hotplug_slot->pci_slot;
641                 rc = sysfs_create_file(&pci_slot->kobj,
642                                        &sn_slot_path_attr.attr);
643                 if (rc)
644                         goto register_err;
645         }
646         dev_dbg(&pci_bus->self->dev, "Registered bus with hotplug\n");
647         return rc;
648
649 register_err:
650         dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
651                 rc);
652
653 alloc_err:
654         if (rc == -ENOMEM)
655                 dev_dbg(&pci_bus->self->dev, "Memory allocation error\n");
656
657         /* destroy THIS element */
658         if (bss_hotplug_slot)
659                 sn_release_slot(bss_hotplug_slot);
660
661         /* destroy anything else on the list */
662         while ((bss_hotplug_slot = sn_hp_destroy()))
663                 pci_hp_deregister(bss_hotplug_slot);
664
665         return rc;
666 }
667
668 static int __init sn_pci_hotplug_init(void)
669 {
670         struct pci_bus *pci_bus = NULL;
671         int rc;
672         int registered = 0;
673
674         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
675                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
676                        __func__);
677                 return -EPERM;
678         }
679
680         INIT_LIST_HEAD(&sn_hp_list);
681
682         while ((pci_bus = pci_find_next_bus(pci_bus))) {
683                 if (!pci_bus->sysdata)
684                         continue;
685
686                 rc = sn_pci_bus_valid(pci_bus);
687                 if (rc != 1) {
688                         dev_dbg(&pci_bus->self->dev, "not a valid hotplug bus\n");
689                         continue;
690                 }
691                 dev_dbg(&pci_bus->self->dev, "valid hotplug bus\n");
692
693                 rc = sn_hotplug_slot_register(pci_bus);
694                 if (!rc) {
695                         registered = 1;
696                 } else {
697                         registered = 0;
698                         break;
699                 }
700         }
701
702         return registered == 1 ? 0 : -ENODEV;
703 }
704
705 static void __exit sn_pci_hotplug_exit(void)
706 {
707         struct hotplug_slot *bss_hotplug_slot;
708
709         while ((bss_hotplug_slot = sn_hp_destroy()))
710                 pci_hp_deregister(bss_hotplug_slot);
711
712         if (!list_empty(&sn_hp_list))
713                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
714 }
715
716 module_init(sn_pci_hotplug_init);
717 module_exit(sn_pci_hotplug_exit);