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PCI hotplug: SGI hotplug: do not use hotplug_slot_attr
[~shefty/rdma-dev.git] / 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/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/pci.h>
16 #include <linux/pci_hotplug.h>
17 #include <linux/proc_fs.h>
18 #include <linux/types.h>
19 #include <linux/mutex.h>
20
21 #include <asm/sn/addrs.h>
22 #include <asm/sn/geo.h>
23 #include <asm/sn/l1.h>
24 #include <asm/sn/module.h>
25 #include <asm/sn/pcibr_provider.h>
26 #include <asm/sn/pcibus_provider_defs.h>
27 #include <asm/sn/pcidev.h>
28 #include <asm/sn/sn_feature_sets.h>
29 #include <asm/sn/sn_sal.h>
30 #include <asm/sn/types.h>
31 #include <linux/acpi.h>
32 #include <asm/sn/acpi.h>
33
34 #include "../pci.h"
35
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("SGI (prarit@sgi.com, dickie@sgi.com, habeck@sgi.com)");
38 MODULE_DESCRIPTION("SGI Altix Hot Plug PCI Controller Driver");
39
40
41 /* SAL call error codes. Keep in sync with prom header io/include/pcibr.h */
42 #define PCI_SLOT_ALREADY_UP             2       /* slot already up */
43 #define PCI_SLOT_ALREADY_DOWN           3       /* slot already down */
44 #define PCI_L1_ERR                      7       /* L1 console command error */
45 #define PCI_EMPTY_33MHZ                 15      /* empty 33 MHz bus */
46
47
48 #define PCIIO_ASIC_TYPE_TIOCA           4
49 #define PCI_L1_QSIZE                    128     /* our L1 message buffer size */
50 #define SN_MAX_HP_SLOTS                 32      /* max hotplug slots */
51 #define SN_SLOT_NAME_SIZE               33      /* size of name string */
52
53 /* internal list head */
54 static struct list_head sn_hp_list;
55
56 /* hotplug_slot struct's private pointer */
57 struct slot {
58         int device_num;
59         struct pci_bus *pci_bus;
60         /* this struct for glue internal only */
61         struct hotplug_slot *hotplug_slot;
62         struct list_head hp_list;
63         char physical_path[SN_SLOT_NAME_SIZE];
64 };
65
66 struct pcibr_slot_enable_resp {
67         int resp_sub_errno;
68         char resp_l1_msg[PCI_L1_QSIZE + 1];
69 };
70
71 struct pcibr_slot_disable_resp {
72         int resp_sub_errno;
73         char resp_l1_msg[PCI_L1_QSIZE + 1];
74 };
75
76 enum sn_pci_req_e {
77         PCI_REQ_SLOT_ELIGIBLE,
78         PCI_REQ_SLOT_DISABLE
79 };
80
81 static int enable_slot(struct hotplug_slot *slot);
82 static int disable_slot(struct hotplug_slot *slot);
83 static inline int get_power_status(struct hotplug_slot *slot, u8 *value);
84
85 static struct hotplug_slot_ops sn_hotplug_slot_ops = {
86         .enable_slot            = enable_slot,
87         .disable_slot           = disable_slot,
88         .get_power_status       = get_power_status,
89 };
90
91 static DEFINE_MUTEX(sn_hotplug_mutex);
92
93 static ssize_t path_show(struct pci_slot *pci_slot, char *buf)
94 {
95         int retval = -ENOENT;
96         struct slot *slot = pci_slot->hotplug->private;
97
98         if (!slot)
99                 return retval;
100
101         retval = sprintf (buf, "%s\n", slot->physical_path);
102         return retval;
103 }
104
105 static struct pci_slot_attribute sn_slot_path_attr = __ATTR_RO(path);
106
107 static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
108 {
109         struct pcibus_info *pcibus_info;
110         u16 busnum, segment, ioboard_type;
111
112         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
113
114         /* Check to see if this is a valid slot on 'pci_bus' */
115         if (!(pcibus_info->pbi_valid_devices & (1 << device)))
116                 return -EPERM;
117
118         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
119         busnum = pcibus_info->pbi_buscommon.bs_persist_busnum;
120         segment = pci_domain_nr(pci_bus) & 0xf;
121
122         /* Do not allow hotplug operations on base I/O cards */
123         if ((ioboard_type == L1_BRICKTYPE_IX ||
124              ioboard_type == L1_BRICKTYPE_IA) &&
125             (segment == 1 && busnum == 0 && device != 1))
126                 return -EPERM;
127
128         return 1;
129 }
130
131 static int sn_pci_bus_valid(struct pci_bus *pci_bus)
132 {
133         struct pcibus_info *pcibus_info;
134         u32 asic_type;
135         u16 ioboard_type;
136
137         /* Don't register slots hanging off the TIOCA bus */
138         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
139         asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
140         if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
141                 return -EPERM;
142
143         /* Only register slots in I/O Bricks that support hotplug */
144         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
145         switch (ioboard_type) {
146                 case L1_BRICKTYPE_IX:
147                 case L1_BRICKTYPE_PX:
148                 case L1_BRICKTYPE_IA:
149                 case L1_BRICKTYPE_PA:
150                 case L1_BOARDTYPE_PCIX3SLOT:
151                         return 1;
152                         break;
153                 default:
154                         return -EPERM;
155                         break;
156         }
157
158         return -EIO;
159 }
160
161 static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
162                                     struct pci_bus *pci_bus, int device,
163                                     char *name)
164 {
165         struct pcibus_info *pcibus_info;
166         struct slot *slot;
167
168         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
169
170         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
171         if (!slot)
172                 return -ENOMEM;
173         bss_hotplug_slot->private = slot;
174
175         slot->device_num = device;
176         slot->pci_bus = pci_bus;
177         sprintf(name, "%04x:%02x:%02x",
178                 pci_domain_nr(pci_bus),
179                 ((u16)pcibus_info->pbi_buscommon.bs_persist_busnum),
180                 device + 1);
181
182         sn_generate_path(pci_bus, slot->physical_path);
183
184         slot->hotplug_slot = bss_hotplug_slot;
185         list_add(&slot->hp_list, &sn_hp_list);
186
187         return 0;
188 }
189
190 static struct hotplug_slot * sn_hp_destroy(void)
191 {
192         struct slot *slot;
193         struct pci_slot *pci_slot;
194         struct hotplug_slot *bss_hotplug_slot = NULL;
195
196         list_for_each_entry(slot, &sn_hp_list, hp_list) {
197                 bss_hotplug_slot = slot->hotplug_slot;
198                 pci_slot = bss_hotplug_slot->pci_slot;
199                 list_del(&((struct slot *)bss_hotplug_slot->private)->
200                          hp_list);
201                 sysfs_remove_file(&pci_slot->kobj,
202                                   &sn_slot_path_attr.attr);
203                 break;
204         }
205         return bss_hotplug_slot;
206 }
207
208 static void sn_bus_free_data(struct pci_dev *dev)
209 {
210         struct pci_bus *subordinate_bus;
211         struct pci_dev *child;
212
213         /* Recursively clean up sn_irq_info structs */
214         if (dev->subordinate) {
215                 subordinate_bus = dev->subordinate;
216                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
217                         sn_bus_free_data(child);
218         }
219         /*
220          * Some drivers may use dma accesses during the
221          * driver remove function. We release the sysdata
222          * areas after the driver remove functions have
223          * been called.
224          */
225         sn_bus_store_sysdata(dev);
226         sn_pci_unfixup_slot(dev);
227 }
228
229 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
230                           int device_num, char **ssdt)
231 {
232         struct slot *slot = bss_hotplug_slot->private;
233         struct pcibus_info *pcibus_info;
234         struct pcibr_slot_enable_resp resp;
235         int rc;
236
237         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
238
239         /*
240          * Power-on and initialize the slot in the SN
241          * PCI infrastructure.
242          */
243         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp, ssdt);
244
245
246         if (rc == PCI_SLOT_ALREADY_UP) {
247                 dev_dbg(&slot->pci_bus->self->dev, "is already active\n");
248                 return 1; /* return 1 to user */
249         }
250
251         if (rc == PCI_L1_ERR) {
252                 dev_dbg(&slot->pci_bus->self->dev,
253                         "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,
260                         "insert failed with error %d sub-error %d\n",
261                         rc, resp.resp_sub_errno);
262                 return -EIO;
263         }
264
265         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
266         pcibus_info->pbi_enabled_devices |= (1 << device_num);
267
268         return 0;
269 }
270
271 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
272                            int device_num, int action)
273 {
274         struct slot *slot = bss_hotplug_slot->private;
275         struct pcibus_info *pcibus_info;
276         struct pcibr_slot_disable_resp resp;
277         int rc;
278
279         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
280
281         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
282
283         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
284             (rc == PCI_SLOT_ALREADY_DOWN)) {
285                 dev_dbg(&slot->pci_bus->self->dev, "Slot %s already inactive\n", slot->physical_path);
286                 return 1; /* return 1 to user */
287         }
288
289         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
290                 dev_dbg(&slot->pci_bus->self->dev,
291                         "Cannot remove last 33MHz card\n");
292                 return -EPERM;
293         }
294
295         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
296                 dev_dbg(&slot->pci_bus->self->dev,
297                         "L1 failure %d with message \n%s\n",
298                         resp.resp_sub_errno, resp.resp_l1_msg);
299                 return -EPERM;
300         }
301
302         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
303                 dev_dbg(&slot->pci_bus->self->dev,
304                         "remove failed with error %d sub-error %d\n",
305                         rc, resp.resp_sub_errno);
306                 return -EIO;
307         }
308
309         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
310                 return 0;
311
312         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
313                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
314                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
315                 dev_dbg(&slot->pci_bus->self->dev, "remove successful\n");
316                 return 0;
317         }
318
319         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
320                 dev_dbg(&slot->pci_bus->self->dev,"remove failed rc = %d\n", rc);
321         }
322
323         return rc;
324 }
325
326 /*
327  * Power up and configure the slot via a SAL call to PROM.
328  * Scan slot (and any children), do any platform specific fixup,
329  * and find device driver.
330  */
331 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
332 {
333         struct slot *slot = bss_hotplug_slot->private;
334         struct pci_bus *new_bus = NULL;
335         struct pci_dev *dev;
336         int func, num_funcs;
337         int new_ppb = 0;
338         int rc;
339         char *ssdt = NULL;
340         void pcibios_fixup_device_resources(struct pci_dev *);
341
342         /* Serialize the Linux PCI infrastructure */
343         mutex_lock(&sn_hotplug_mutex);
344
345         /*
346          * Power-on and initialize the slot in the SN
347          * PCI infrastructure. Also, retrieve the ACPI SSDT
348          * table for the slot (if ACPI capable PROM).
349          */
350         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
351         if (rc) {
352                 mutex_unlock(&sn_hotplug_mutex);
353                 return rc;
354         }
355
356         if (ssdt)
357                 ssdt = __va(ssdt);
358         /* Add the new SSDT for the slot to the ACPI namespace */
359         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
360                 acpi_status ret;
361
362                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
363                 if (ACPI_FAILURE(ret)) {
364                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
365                                __func__, ret);
366                         /* try to continue on */
367                 }
368         }
369
370         num_funcs = pci_scan_slot(slot->pci_bus,
371                                   PCI_DEVFN(slot->device_num + 1, 0));
372         if (!num_funcs) {
373                 dev_dbg(&slot->pci_bus->self->dev, "no device in slot\n");
374                 mutex_unlock(&sn_hotplug_mutex);
375                 return -ENODEV;
376         }
377
378         /*
379          * Map SN resources for all functions on the card
380          * to the Linux PCI interface and tell the drivers
381          * about them.
382          */
383         for (func = 0; func < num_funcs;  func++) {
384                 dev = pci_get_slot(slot->pci_bus,
385                                    PCI_DEVFN(slot->device_num + 1,
386                                              PCI_FUNC(func)));
387                 if (dev) {
388                         /* Need to do slot fixup on PPB before fixup of children
389                          * (PPB's pcidev_info needs to be in pcidev_info list
390                          * before child's SN_PCIDEV_INFO() call to setup
391                          * pdi_host_pcidev_info).
392                          */
393                         pcibios_fixup_device_resources(dev);
394                         if (SN_ACPI_BASE_SUPPORT())
395                                 sn_acpi_slot_fixup(dev);
396                         else
397                                 sn_io_slot_fixup(dev);
398                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
399                                 unsigned char sec_bus;
400                                 pci_read_config_byte(dev, PCI_SECONDARY_BUS,
401                                                      &sec_bus);
402                                 new_bus = pci_add_new_bus(dev->bus, dev,
403                                                           sec_bus);
404                                 pci_scan_child_bus(new_bus);
405                                 new_ppb = 1;
406                         }
407                         pci_dev_put(dev);
408                 }
409         }
410
411         /*
412          * Add the slot's devices to the ACPI infrastructure */
413         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
414                 unsigned long long adr;
415                 struct acpi_device *pdevice;
416                 struct acpi_device *device;
417                 acpi_handle phandle;
418                 acpi_handle chandle = NULL;
419                 acpi_handle rethandle;
420                 acpi_status ret;
421
422                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
423
424                 if (acpi_bus_get_device(phandle, &pdevice)) {
425                         dev_dbg(&slot->pci_bus->self->dev,
426                                 "no parent device, assuming NULL\n");
427                         pdevice = NULL;
428                 }
429
430                 /*
431                  * Walk the rootbus node's immediate children looking for
432                  * the slot's device node(s). There can be more than
433                  * one for multifunction devices.
434                  */
435                 for (;;) {
436                         rethandle = NULL;
437                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
438                                                    phandle, chandle,
439                                                    &rethandle);
440
441                         if (ret == AE_NOT_FOUND || rethandle == NULL)
442                                 break;
443
444                         chandle = rethandle;
445
446                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
447                                                     NULL, &adr);
448
449                         if (ACPI_SUCCESS(ret) &&
450                             (adr>>16) == (slot->device_num + 1)) {
451
452                                 ret = acpi_bus_add(&device, pdevice, chandle,
453                                                    ACPI_BUS_TYPE_DEVICE);
454                                 if (ACPI_FAILURE(ret)) {
455                                         printk(KERN_ERR "%s: acpi_bus_add "
456                                                "failed (0x%x) for slot %d "
457                                                "func %d\n", __func__,
458                                                ret, (int)(adr>>16),
459                                                (int)(adr&0xffff));
460                                         /* try to continue on */
461                                 } else {
462                                         acpi_bus_start(device);
463                                 }
464                         }
465                 }
466         }
467
468         /* Call the driver for the new device */
469         pci_bus_add_devices(slot->pci_bus);
470         /* Call the drivers for the new devices subordinate to PPB */
471         if (new_ppb)
472                 pci_bus_add_devices(new_bus);
473
474         mutex_unlock(&sn_hotplug_mutex);
475
476         if (rc == 0)
477                 dev_dbg(&slot->pci_bus->self->dev,
478                         "insert operation successful\n");
479         else
480                 dev_dbg(&slot->pci_bus->self->dev,
481                         "insert operation failed rc = %d\n", rc);
482
483         return rc;
484 }
485
486 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
487 {
488         struct slot *slot = bss_hotplug_slot->private;
489         struct pci_dev *dev;
490         int func;
491         int rc;
492         acpi_owner_id ssdt_id = 0;
493
494         /* Acquire update access to the bus */
495         mutex_lock(&sn_hotplug_mutex);
496
497         /* is it okay to bring this slot down? */
498         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
499                              PCI_REQ_SLOT_ELIGIBLE);
500         if (rc)
501                 goto leaving;
502
503         /* free the ACPI resources for the slot */
504         if (SN_ACPI_BASE_SUPPORT() &&
505             PCI_CONTROLLER(slot->pci_bus)->acpi_handle) {
506                 unsigned long long adr;
507                 struct acpi_device *device;
508                 acpi_handle phandle;
509                 acpi_handle chandle = NULL;
510                 acpi_handle rethandle;
511                 acpi_status ret;
512
513                 /* Get the rootbus node pointer */
514                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
515
516                 /*
517                  * Walk the rootbus node's immediate children looking for
518                  * the slot's device node(s). There can be more than
519                  * one for multifunction devices.
520                  */
521                 for (;;) {
522                         rethandle = NULL;
523                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
524                                                    phandle, chandle,
525                                                    &rethandle);
526
527                         if (ret == AE_NOT_FOUND || rethandle == NULL)
528                                 break;
529
530                         chandle = rethandle;
531
532                         ret = acpi_evaluate_integer(chandle,
533                                                     METHOD_NAME__ADR,
534                                                     NULL, &adr);
535                         if (ACPI_SUCCESS(ret) &&
536                             (adr>>16) == (slot->device_num + 1)) {
537                                 /* retain the owner id */
538                                 acpi_get_id(chandle, &ssdt_id);
539
540                                 ret = acpi_bus_get_device(chandle,
541                                                           &device);
542                                 if (ACPI_SUCCESS(ret))
543                                         acpi_bus_trim(device, 1);
544                         }
545                 }
546
547         }
548
549         /* Free the SN resources assigned to the Linux device.*/
550         for (func = 0; func < 8;  func++) {
551                 dev = pci_get_slot(slot->pci_bus,
552                                    PCI_DEVFN(slot->device_num + 1,
553                                              PCI_FUNC(func)));
554                 if (dev) {
555                         sn_bus_free_data(dev);
556                         pci_remove_bus_device(dev);
557                         pci_dev_put(dev);
558                 }
559         }
560
561         /* Remove the SSDT for the slot from the ACPI namespace */
562         if (SN_ACPI_BASE_SUPPORT() && ssdt_id) {
563                 acpi_status ret;
564                 ret = acpi_unload_table_id(ssdt_id);
565                 if (ACPI_FAILURE(ret)) {
566                         printk(KERN_ERR "%s: acpi_unload_table_id "
567                                "failed (0x%x) for id %d\n",
568                                __func__, ret, ssdt_id);
569                         /* try to continue on */
570                 }
571         }
572
573         /* free the collected sysdata pointers */
574         sn_bus_free_sysdata();
575
576         /* Deactivate slot */
577         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
578                              PCI_REQ_SLOT_DISABLE);
579  leaving:
580         /* Release the bus lock */
581         mutex_unlock(&sn_hotplug_mutex);
582
583         return rc;
584 }
585
586 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
587                                    u8 *value)
588 {
589         struct slot *slot = bss_hotplug_slot->private;
590         struct pcibus_info *pcibus_info;
591         u32 power;
592
593         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
594         mutex_lock(&sn_hotplug_mutex);
595         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
596         *value = power ? 1 : 0;
597         mutex_unlock(&sn_hotplug_mutex);
598         return 0;
599 }
600
601 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
602 {
603         kfree(bss_hotplug_slot->info);
604         kfree(bss_hotplug_slot->private);
605         kfree(bss_hotplug_slot);
606 }
607
608 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
609 {
610         int device;
611         struct pci_slot *pci_slot;
612         struct hotplug_slot *bss_hotplug_slot;
613         char name[SN_SLOT_NAME_SIZE];
614         int rc = 0;
615
616         /*
617          * Currently only four devices are supported,
618          * in the future there maybe more -- up to 32.
619          */
620
621         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
622                 if (sn_pci_slot_valid(pci_bus, device) != 1)
623                         continue;
624
625                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
626                                            GFP_KERNEL);
627                 if (!bss_hotplug_slot) {
628                         rc = -ENOMEM;
629                         goto alloc_err;
630                 }
631
632                 bss_hotplug_slot->info =
633                         kzalloc(sizeof(struct hotplug_slot_info),
634                                 GFP_KERNEL);
635                 if (!bss_hotplug_slot->info) {
636                         rc = -ENOMEM;
637                         goto alloc_err;
638                 }
639
640                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
641                                              pci_bus, device, name)) {
642                         rc = -ENOMEM;
643                         goto alloc_err;
644                 }
645                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
646                 bss_hotplug_slot->release = &sn_release_slot;
647
648                 rc = pci_hp_register(bss_hotplug_slot, pci_bus, device, name);
649                 if (rc)
650                         goto register_err;
651
652                 pci_slot = bss_hotplug_slot->pci_slot;
653                 rc = sysfs_create_file(&pci_slot->kobj,
654                                        &sn_slot_path_attr.attr);
655                 if (rc)
656                         goto register_err;
657         }
658         dev_dbg(&pci_bus->self->dev, "Registered bus with hotplug\n");
659         return rc;
660
661 register_err:
662         dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
663                 rc);
664
665 alloc_err:
666         if (rc == -ENOMEM)
667                 dev_dbg(&pci_bus->self->dev, "Memory allocation error\n");
668
669         /* destroy THIS element */
670         if (bss_hotplug_slot)
671                 sn_release_slot(bss_hotplug_slot);
672
673         /* destroy anything else on the list */
674         while ((bss_hotplug_slot = sn_hp_destroy()))
675                 pci_hp_deregister(bss_hotplug_slot);
676
677         return rc;
678 }
679
680 static int __init sn_pci_hotplug_init(void)
681 {
682         struct pci_bus *pci_bus = NULL;
683         int rc;
684         int registered = 0;
685
686         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
687                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
688                        __func__);
689                 return -EPERM;
690         }
691
692         INIT_LIST_HEAD(&sn_hp_list);
693
694         while ((pci_bus = pci_find_next_bus(pci_bus))) {
695                 if (!pci_bus->sysdata)
696                         continue;
697
698                 rc = sn_pci_bus_valid(pci_bus);
699                 if (rc != 1) {
700                         dev_dbg(&pci_bus->self->dev, "not a valid hotplug bus\n");
701                         continue;
702                 }
703                 dev_dbg(&pci_bus->self->dev, "valid hotplug bus\n");
704
705                 rc = sn_hotplug_slot_register(pci_bus);
706                 if (!rc) {
707                         registered = 1;
708                 } else {
709                         registered = 0;
710                         break;
711                 }
712         }
713
714         return registered == 1 ? 0 : -ENODEV;
715 }
716
717 static void __exit sn_pci_hotplug_exit(void)
718 {
719         struct hotplug_slot *bss_hotplug_slot;
720
721         while ((bss_hotplug_slot = sn_hp_destroy()))
722                 pci_hp_deregister(bss_hotplug_slot);
723
724         if (!list_empty(&sn_hp_list))
725                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
726 }
727
728 module_init(sn_pci_hotplug_init);
729 module_exit(sn_pci_hotplug_exit);