Merge branches 'x86/xen', 'x86/build', 'x86/microcode', 'x86/mm-debug-v2', 'x86/memor...
[linux-2.6] / 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         .owner                  = THIS_MODULE,
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 hotplug_slot *bss_hotplug_slot,
95                           char *buf)
96 {
97         int retval = -ENOENT;
98         struct slot *slot = bss_hotplug_slot->private;
99
100         if (!slot)
101                 return retval;
102
103         retval = sprintf (buf, "%s\n", slot->physical_path);
104         return retval;
105 }
106
107 static struct hotplug_slot_attribute sn_slot_path_attr = __ATTR_RO(path);
108
109 static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
110 {
111         struct pcibus_info *pcibus_info;
112         u16 busnum, segment, ioboard_type;
113
114         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
115
116         /* Check to see if this is a valid slot on 'pci_bus' */
117         if (!(pcibus_info->pbi_valid_devices & (1 << device)))
118                 return -EPERM;
119
120         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
121         busnum = pcibus_info->pbi_buscommon.bs_persist_busnum;
122         segment = pci_domain_nr(pci_bus) & 0xf;
123
124         /* Do not allow hotplug operations on base I/O cards */
125         if ((ioboard_type == L1_BRICKTYPE_IX ||
126              ioboard_type == L1_BRICKTYPE_IA) &&
127             (segment == 1 && busnum == 0 && device != 1))
128                 return -EPERM;
129
130         return 1;
131 }
132
133 static int sn_pci_bus_valid(struct pci_bus *pci_bus)
134 {
135         struct pcibus_info *pcibus_info;
136         u32 asic_type;
137         u16 ioboard_type;
138
139         /* Don't register slots hanging off the TIOCA bus */
140         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
141         asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
142         if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
143                 return -EPERM;
144
145         /* Only register slots in I/O Bricks that support hotplug */
146         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
147         switch (ioboard_type) {
148                 case L1_BRICKTYPE_IX:
149                 case L1_BRICKTYPE_PX:
150                 case L1_BRICKTYPE_IA:
151                 case L1_BRICKTYPE_PA:
152                 case L1_BOARDTYPE_PCIX3SLOT:
153                         return 1;
154                         break;
155                 default:
156                         return -EPERM;
157                         break;
158         }
159
160         return -EIO;
161 }
162
163 static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
164                                     struct pci_bus *pci_bus, int device)
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         bss_hotplug_slot->name = kmalloc(SN_SLOT_NAME_SIZE, GFP_KERNEL);
177         if (!bss_hotplug_slot->name) {
178                 kfree(bss_hotplug_slot->private);
179                 return -ENOMEM;
180         }
181
182         slot->device_num = device;
183         slot->pci_bus = pci_bus;
184         sprintf(bss_hotplug_slot->name, "%04x:%02x:%02x",
185                 pci_domain_nr(pci_bus),
186                 ((u16)pcibus_info->pbi_buscommon.bs_persist_busnum),
187                 device + 1);
188
189         sn_generate_path(pci_bus, slot->physical_path);
190
191         slot->hotplug_slot = bss_hotplug_slot;
192         list_add(&slot->hp_list, &sn_hp_list);
193
194         return 0;
195 }
196
197 static struct hotplug_slot * sn_hp_destroy(void)
198 {
199         struct slot *slot;
200         struct pci_slot *pci_slot;
201         struct hotplug_slot *bss_hotplug_slot = NULL;
202
203         list_for_each_entry(slot, &sn_hp_list, hp_list) {
204                 bss_hotplug_slot = slot->hotplug_slot;
205                 pci_slot = bss_hotplug_slot->pci_slot;
206                 list_del(&((struct slot *)bss_hotplug_slot->private)->
207                          hp_list);
208                 sysfs_remove_file(&pci_slot->kobj,
209                                   &sn_slot_path_attr.attr);
210                 break;
211         }
212         return bss_hotplug_slot;
213 }
214
215 static void sn_bus_free_data(struct pci_dev *dev)
216 {
217         struct pci_bus *subordinate_bus;
218         struct pci_dev *child;
219
220         /* Recursively clean up sn_irq_info structs */
221         if (dev->subordinate) {
222                 subordinate_bus = dev->subordinate;
223                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
224                         sn_bus_free_data(child);
225         }
226         /*
227          * Some drivers may use dma accesses during the
228          * driver remove function. We release the sysdata
229          * areas after the driver remove functions have
230          * been called.
231          */
232         sn_bus_store_sysdata(dev);
233         sn_pci_unfixup_slot(dev);
234 }
235
236 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
237                           int device_num, char **ssdt)
238 {
239         struct slot *slot = bss_hotplug_slot->private;
240         struct pcibus_info *pcibus_info;
241         struct pcibr_slot_enable_resp resp;
242         int rc;
243
244         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
245
246         /*
247          * Power-on and initialize the slot in the SN
248          * PCI infrastructure.
249          */
250         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp, ssdt);
251
252
253         if (rc == PCI_SLOT_ALREADY_UP) {
254                 dev_dbg(&slot->pci_bus->self->dev, "is already active\n");
255                 return 1; /* return 1 to user */
256         }
257
258         if (rc == PCI_L1_ERR) {
259                 dev_dbg(&slot->pci_bus->self->dev,
260                         "L1 failure %d with message: %s",
261                         resp.resp_sub_errno, resp.resp_l1_msg);
262                 return -EPERM;
263         }
264
265         if (rc) {
266                 dev_dbg(&slot->pci_bus->self->dev,
267                         "insert failed with error %d sub-error %d\n",
268                         rc, resp.resp_sub_errno);
269                 return -EIO;
270         }
271
272         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
273         pcibus_info->pbi_enabled_devices |= (1 << device_num);
274
275         return 0;
276 }
277
278 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
279                            int device_num, int action)
280 {
281         struct slot *slot = bss_hotplug_slot->private;
282         struct pcibus_info *pcibus_info;
283         struct pcibr_slot_disable_resp resp;
284         int rc;
285
286         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
287
288         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
289
290         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
291             (rc == PCI_SLOT_ALREADY_DOWN)) {
292                 dev_dbg(&slot->pci_bus->self->dev, "Slot %s already inactive\n", slot->physical_path);
293                 return 1; /* return 1 to user */
294         }
295
296         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
297                 dev_dbg(&slot->pci_bus->self->dev,
298                         "Cannot remove last 33MHz card\n");
299                 return -EPERM;
300         }
301
302         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
303                 dev_dbg(&slot->pci_bus->self->dev,
304                         "L1 failure %d with message \n%s\n",
305                         resp.resp_sub_errno, resp.resp_l1_msg);
306                 return -EPERM;
307         }
308
309         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
310                 dev_dbg(&slot->pci_bus->self->dev,
311                         "remove failed with error %d sub-error %d\n",
312                         rc, resp.resp_sub_errno);
313                 return -EIO;
314         }
315
316         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
317                 return 0;
318
319         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
320                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
321                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
322                 dev_dbg(&slot->pci_bus->self->dev, "remove successful\n");
323                 return 0;
324         }
325
326         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
327                 dev_dbg(&slot->pci_bus->self->dev,"remove failed rc = %d\n", rc);
328         }
329
330         return rc;
331 }
332
333 /*
334  * Power up and configure the slot via a SAL call to PROM.
335  * Scan slot (and any children), do any platform specific fixup,
336  * and find device driver.
337  */
338 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
339 {
340         struct slot *slot = bss_hotplug_slot->private;
341         struct pci_bus *new_bus = NULL;
342         struct pci_dev *dev;
343         int func, num_funcs;
344         int new_ppb = 0;
345         int rc;
346         char *ssdt = NULL;
347         void pcibios_fixup_device_resources(struct pci_dev *);
348
349         /* Serialize the Linux PCI infrastructure */
350         mutex_lock(&sn_hotplug_mutex);
351
352         /*
353          * Power-on and initialize the slot in the SN
354          * PCI infrastructure. Also, retrieve the ACPI SSDT
355          * table for the slot (if ACPI capable PROM).
356          */
357         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
358         if (rc) {
359                 mutex_unlock(&sn_hotplug_mutex);
360                 return rc;
361         }
362
363         if (ssdt)
364                 ssdt = __va(ssdt);
365         /* Add the new SSDT for the slot to the ACPI namespace */
366         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
367                 acpi_status ret;
368
369                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
370                 if (ACPI_FAILURE(ret)) {
371                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
372                                __func__, ret);
373                         /* try to continue on */
374                 }
375         }
376
377         num_funcs = pci_scan_slot(slot->pci_bus,
378                                   PCI_DEVFN(slot->device_num + 1, 0));
379         if (!num_funcs) {
380                 dev_dbg(&slot->pci_bus->self->dev, "no device in slot\n");
381                 mutex_unlock(&sn_hotplug_mutex);
382                 return -ENODEV;
383         }
384
385         /*
386          * Map SN resources for all functions on the card
387          * to the Linux PCI interface and tell the drivers
388          * about them.
389          */
390         for (func = 0; func < num_funcs;  func++) {
391                 dev = pci_get_slot(slot->pci_bus,
392                                    PCI_DEVFN(slot->device_num + 1,
393                                              PCI_FUNC(func)));
394                 if (dev) {
395                         /* Need to do slot fixup on PPB before fixup of children
396                          * (PPB's pcidev_info needs to be in pcidev_info list
397                          * before child's SN_PCIDEV_INFO() call to setup
398                          * pdi_host_pcidev_info).
399                          */
400                         pcibios_fixup_device_resources(dev);
401                         if (SN_ACPI_BASE_SUPPORT())
402                                 sn_acpi_slot_fixup(dev);
403                         else
404                                 sn_io_slot_fixup(dev);
405                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
406                                 unsigned char sec_bus;
407                                 pci_read_config_byte(dev, PCI_SECONDARY_BUS,
408                                                      &sec_bus);
409                                 new_bus = pci_add_new_bus(dev->bus, dev,
410                                                           sec_bus);
411                                 pci_scan_child_bus(new_bus);
412                                 new_ppb = 1;
413                         }
414                         pci_dev_put(dev);
415                 }
416         }
417
418         /*
419          * Add the slot's devices to the ACPI infrastructure */
420         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
421                 unsigned long adr;
422                 struct acpi_device *pdevice;
423                 struct acpi_device *device;
424                 acpi_handle phandle;
425                 acpi_handle chandle = NULL;
426                 acpi_handle rethandle;
427                 acpi_status ret;
428
429                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
430
431                 if (acpi_bus_get_device(phandle, &pdevice)) {
432                         dev_dbg(&slot->pci_bus->self->dev,
433                                 "no parent device, assuming NULL\n");
434                         pdevice = NULL;
435                 }
436
437                 /*
438                  * Walk the rootbus node's immediate children looking for
439                  * the slot's device node(s). There can be more than
440                  * one for multifunction devices.
441                  */
442                 for (;;) {
443                         rethandle = NULL;
444                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
445                                                    phandle, chandle,
446                                                    &rethandle);
447
448                         if (ret == AE_NOT_FOUND || rethandle == NULL)
449                                 break;
450
451                         chandle = rethandle;
452
453                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
454                                                     NULL, &adr);
455
456                         if (ACPI_SUCCESS(ret) &&
457                             (adr>>16) == (slot->device_num + 1)) {
458
459                                 ret = acpi_bus_add(&device, pdevice, chandle,
460                                                    ACPI_BUS_TYPE_DEVICE);
461                                 if (ACPI_FAILURE(ret)) {
462                                         printk(KERN_ERR "%s: acpi_bus_add "
463                                                "failed (0x%x) for slot %d "
464                                                "func %d\n", __func__,
465                                                ret, (int)(adr>>16),
466                                                (int)(adr&0xffff));
467                                         /* try to continue on */
468                                 } else {
469                                         acpi_bus_start(device);
470                                 }
471                         }
472                 }
473         }
474
475         /* Call the driver for the new device */
476         pci_bus_add_devices(slot->pci_bus);
477         /* Call the drivers for the new devices subordinate to PPB */
478         if (new_ppb)
479                 pci_bus_add_devices(new_bus);
480
481         mutex_unlock(&sn_hotplug_mutex);
482
483         if (rc == 0)
484                 dev_dbg(&slot->pci_bus->self->dev,
485                         "insert operation successful\n");
486         else
487                 dev_dbg(&slot->pci_bus->self->dev,
488                         "insert operation failed rc = %d\n", rc);
489
490         return rc;
491 }
492
493 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
494 {
495         struct slot *slot = bss_hotplug_slot->private;
496         struct pci_dev *dev;
497         int func;
498         int rc;
499         acpi_owner_id ssdt_id = 0;
500
501         /* Acquire update access to the bus */
502         mutex_lock(&sn_hotplug_mutex);
503
504         /* is it okay to bring this slot down? */
505         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
506                              PCI_REQ_SLOT_ELIGIBLE);
507         if (rc)
508                 goto leaving;
509
510         /* free the ACPI resources for the slot */
511         if (SN_ACPI_BASE_SUPPORT() &&
512             PCI_CONTROLLER(slot->pci_bus)->acpi_handle) {
513                 unsigned long adr;
514                 struct acpi_device *device;
515                 acpi_handle phandle;
516                 acpi_handle chandle = NULL;
517                 acpi_handle rethandle;
518                 acpi_status ret;
519
520                 /* Get the rootbus node pointer */
521                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
522
523                 /*
524                  * Walk the rootbus node's immediate children looking for
525                  * the slot's device node(s). There can be more than
526                  * one for multifunction devices.
527                  */
528                 for (;;) {
529                         rethandle = NULL;
530                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
531                                                    phandle, chandle,
532                                                    &rethandle);
533
534                         if (ret == AE_NOT_FOUND || rethandle == NULL)
535                                 break;
536
537                         chandle = rethandle;
538
539                         ret = acpi_evaluate_integer(chandle,
540                                                     METHOD_NAME__ADR,
541                                                     NULL, &adr);
542                         if (ACPI_SUCCESS(ret) &&
543                             (adr>>16) == (slot->device_num + 1)) {
544                                 /* retain the owner id */
545                                 acpi_get_id(chandle, &ssdt_id);
546
547                                 ret = acpi_bus_get_device(chandle,
548                                                           &device);
549                                 if (ACPI_SUCCESS(ret))
550                                         acpi_bus_trim(device, 1);
551                         }
552                 }
553
554         }
555
556         /* Free the SN resources assigned to the Linux device.*/
557         for (func = 0; func < 8;  func++) {
558                 dev = pci_get_slot(slot->pci_bus,
559                                    PCI_DEVFN(slot->device_num + 1,
560                                              PCI_FUNC(func)));
561                 if (dev) {
562                         sn_bus_free_data(dev);
563                         pci_remove_bus_device(dev);
564                         pci_dev_put(dev);
565                 }
566         }
567
568         /* Remove the SSDT for the slot from the ACPI namespace */
569         if (SN_ACPI_BASE_SUPPORT() && ssdt_id) {
570                 acpi_status ret;
571                 ret = acpi_unload_table_id(ssdt_id);
572                 if (ACPI_FAILURE(ret)) {
573                         printk(KERN_ERR "%s: acpi_unload_table_id "
574                                "failed (0x%x) for id %d\n",
575                                __func__, ret, ssdt_id);
576                         /* try to continue on */
577                 }
578         }
579
580         /* free the collected sysdata pointers */
581         sn_bus_free_sysdata();
582
583         /* Deactivate slot */
584         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
585                              PCI_REQ_SLOT_DISABLE);
586  leaving:
587         /* Release the bus lock */
588         mutex_unlock(&sn_hotplug_mutex);
589
590         return rc;
591 }
592
593 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
594                                    u8 *value)
595 {
596         struct slot *slot = bss_hotplug_slot->private;
597         struct pcibus_info *pcibus_info;
598         u32 power;
599
600         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
601         mutex_lock(&sn_hotplug_mutex);
602         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
603         *value = power ? 1 : 0;
604         mutex_unlock(&sn_hotplug_mutex);
605         return 0;
606 }
607
608 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
609 {
610         kfree(bss_hotplug_slot->info);
611         kfree(bss_hotplug_slot->name);
612         kfree(bss_hotplug_slot->private);
613         kfree(bss_hotplug_slot);
614 }
615
616 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
617 {
618         int device;
619         struct pci_slot *pci_slot;
620         struct hotplug_slot *bss_hotplug_slot;
621         int rc = 0;
622
623         /*
624          * Currently only four devices are supported,
625          * in the future there maybe more -- up to 32.
626          */
627
628         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
629                 if (sn_pci_slot_valid(pci_bus, device) != 1)
630                         continue;
631
632                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
633                                            GFP_KERNEL);
634                 if (!bss_hotplug_slot) {
635                         rc = -ENOMEM;
636                         goto alloc_err;
637                 }
638
639                 bss_hotplug_slot->info =
640                         kzalloc(sizeof(struct hotplug_slot_info),
641                                 GFP_KERNEL);
642                 if (!bss_hotplug_slot->info) {
643                         rc = -ENOMEM;
644                         goto alloc_err;
645                 }
646
647                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
648                                              pci_bus, device)) {
649                         rc = -ENOMEM;
650                         goto alloc_err;
651                 }
652
653                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
654                 bss_hotplug_slot->release = &sn_release_slot;
655
656                 rc = pci_hp_register(bss_hotplug_slot, pci_bus, device);
657                 if (rc)
658                         goto register_err;
659
660                 pci_slot = bss_hotplug_slot->pci_slot;
661                 rc = sysfs_create_file(&pci_slot->kobj,
662                                        &sn_slot_path_attr.attr);
663                 if (rc)
664                         goto register_err;
665         }
666         dev_dbg(&pci_bus->self->dev, "Registered bus with hotplug\n");
667         return rc;
668
669 register_err:
670         dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
671                 rc);
672
673 alloc_err:
674         if (rc == -ENOMEM)
675                 dev_dbg(&pci_bus->self->dev, "Memory allocation error\n");
676
677         /* destroy THIS element */
678         if (bss_hotplug_slot)
679                 sn_release_slot(bss_hotplug_slot);
680
681         /* destroy anything else on the list */
682         while ((bss_hotplug_slot = sn_hp_destroy()))
683                 pci_hp_deregister(bss_hotplug_slot);
684
685         return rc;
686 }
687
688 static int sn_pci_hotplug_init(void)
689 {
690         struct pci_bus *pci_bus = NULL;
691         int rc;
692         int registered = 0;
693
694         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
695                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
696                        __func__);
697                 return -EPERM;
698         }
699
700         INIT_LIST_HEAD(&sn_hp_list);
701
702         while ((pci_bus = pci_find_next_bus(pci_bus))) {
703                 if (!pci_bus->sysdata)
704                         continue;
705
706                 rc = sn_pci_bus_valid(pci_bus);
707                 if (rc != 1) {
708                         dev_dbg(&pci_bus->self->dev, "not a valid hotplug bus\n");
709                         continue;
710                 }
711                 dev_dbg(&pci_bus->self->dev, "valid hotplug bus\n");
712
713                 rc = sn_hotplug_slot_register(pci_bus);
714                 if (!rc) {
715                         registered = 1;
716                 } else {
717                         registered = 0;
718                         break;
719                 }
720         }
721
722         return registered == 1 ? 0 : -ENODEV;
723 }
724
725 static void sn_pci_hotplug_exit(void)
726 {
727         struct hotplug_slot *bss_hotplug_slot;
728
729         while ((bss_hotplug_slot = sn_hp_destroy()))
730                 pci_hp_deregister(bss_hotplug_slot);
731
732         if (!list_empty(&sn_hp_list))
733                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
734 }
735
736 module_init(sn_pci_hotplug_init);
737 module_exit(sn_pci_hotplug_exit);