1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * ACPI PCI Hot Plug IBM Extension |
4 | * |
5 | * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com> |
6 | * Copyright (C) 2004 IBM Corp. |
7 | * |
8 | * All rights reserved. |
9 | * |
10 | * Send feedback to <vernux@us.ibm.com> |
11 | * |
12 | */ |
13 | |
14 | #define pr_fmt(fmt) "acpiphp_ibm: " fmt |
15 | |
16 | #include <linux/init.h> |
17 | #include <linux/slab.h> |
18 | #include <linux/module.h> |
19 | #include <linux/kernel.h> |
20 | #include <linux/sysfs.h> |
21 | #include <linux/kobject.h> |
22 | #include <linux/moduleparam.h> |
23 | #include <linux/pci.h> |
24 | #include <linux/uaccess.h> |
25 | |
26 | #include "acpiphp.h" |
27 | #include "../pci.h" |
28 | |
29 | #define DRIVER_VERSION "1.0.1" |
30 | #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" |
31 | #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" |
32 | |
33 | |
34 | MODULE_AUTHOR(DRIVER_AUTHOR); |
35 | MODULE_DESCRIPTION(DRIVER_DESC); |
36 | MODULE_LICENSE("GPL" ); |
37 | MODULE_VERSION(DRIVER_VERSION); |
38 | |
39 | #define FOUND_APCI 0x61504349 |
40 | /* these are the names for the IBM ACPI pseudo-device */ |
41 | #define IBM_HARDWARE_ID1 "IBM37D0" |
42 | #define IBM_HARDWARE_ID2 "IBM37D4" |
43 | |
44 | #define hpslot_to_sun(A) (to_slot(A)->sun) |
45 | |
46 | /* union apci_descriptor - allows access to the |
47 | * various device descriptors that are embedded in the |
48 | * aPCI table |
49 | */ |
50 | union apci_descriptor { |
51 | struct { |
52 | char sig[4]; |
53 | u8 len; |
54 | } ; |
55 | struct { |
56 | u8 type; |
57 | u8 len; |
58 | u16 slot_id; |
59 | u8 bus_id; |
60 | u8 dev_num; |
61 | u8 slot_num; |
62 | u8 slot_attr[2]; |
63 | u8 attn; |
64 | u8 status[2]; |
65 | u8 sun; |
66 | u8 res[3]; |
67 | } slot; |
68 | struct { |
69 | u8 type; |
70 | u8 len; |
71 | } generic; |
72 | }; |
73 | |
74 | /* struct notification - keeps info about the device |
75 | * that cause the ACPI notification event |
76 | */ |
77 | struct notification { |
78 | struct acpi_device *device; |
79 | u8 event; |
80 | }; |
81 | |
82 | static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); |
83 | static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); |
84 | static void ibm_handle_events(acpi_handle handle, u32 event, void *context); |
85 | static int ibm_get_table_from_acpi(char **bufp); |
86 | static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, |
87 | struct bin_attribute *bin_attr, |
88 | char *buffer, loff_t pos, size_t size); |
89 | static acpi_status __init ibm_find_acpi_device(acpi_handle handle, |
90 | u32 lvl, void *context, void **rv); |
91 | static int __init ibm_acpiphp_init(void); |
92 | static void __exit ibm_acpiphp_exit(void); |
93 | |
94 | static acpi_handle ibm_acpi_handle; |
95 | static struct notification ibm_note; |
96 | static struct bin_attribute ibm_apci_table_attr __ro_after_init = { |
97 | .attr = { |
98 | .name = "apci_table" , |
99 | .mode = S_IRUGO, |
100 | }, |
101 | .read = ibm_read_apci_table, |
102 | .write = NULL, |
103 | }; |
104 | static struct acpiphp_attention_info ibm_attention_info = |
105 | { |
106 | .set_attn = ibm_set_attention_status, |
107 | .get_attn = ibm_get_attention_status, |
108 | .owner = THIS_MODULE, |
109 | }; |
110 | |
111 | /** |
112 | * ibm_slot_from_id - workaround for bad ibm hardware |
113 | * @id: the slot number that linux refers to the slot by |
114 | * |
115 | * Description: This method returns the aCPI slot descriptor |
116 | * corresponding to the Linux slot number. This descriptor |
117 | * has info about the aPCI slot id and attention status. |
118 | * This descriptor must be freed using kfree when done. |
119 | */ |
120 | static union apci_descriptor *ibm_slot_from_id(int id) |
121 | { |
122 | int ind = 0, size; |
123 | union apci_descriptor *ret = NULL, *des; |
124 | char *table; |
125 | |
126 | size = ibm_get_table_from_acpi(bufp: &table); |
127 | if (size < 0) |
128 | return NULL; |
129 | des = (union apci_descriptor *)table; |
130 | if (memcmp(p: des->header.sig, q: "aPCI" , size: 4) != 0) |
131 | goto ibm_slot_done; |
132 | |
133 | des = (union apci_descriptor *)&table[ind += des->header.len]; |
134 | while (ind < size && (des->generic.type != 0x82 || |
135 | des->slot.slot_num != id)) { |
136 | des = (union apci_descriptor *)&table[ind += des->generic.len]; |
137 | } |
138 | |
139 | if (ind < size && des->slot.slot_num == id) |
140 | ret = des; |
141 | |
142 | ibm_slot_done: |
143 | if (ret) { |
144 | ret = kmalloc(size: sizeof(union apci_descriptor), GFP_KERNEL); |
145 | if (ret) |
146 | memcpy(ret, des, sizeof(union apci_descriptor)); |
147 | } |
148 | kfree(objp: table); |
149 | return ret; |
150 | } |
151 | |
152 | /** |
153 | * ibm_set_attention_status - callback method to set the attention LED |
154 | * @slot: the hotplug_slot to work with |
155 | * @status: what to set the LED to (0 or 1) |
156 | * |
157 | * Description: This method is registered with the acpiphp module as a |
158 | * callback to do the device specific task of setting the LED status. |
159 | */ |
160 | static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) |
161 | { |
162 | union acpi_object args[2]; |
163 | struct acpi_object_list params = { .pointer = args, .count = 2 }; |
164 | acpi_status stat; |
165 | unsigned long long rc; |
166 | union apci_descriptor *ibm_slot; |
167 | int id = hpslot_to_sun(slot); |
168 | |
169 | ibm_slot = ibm_slot_from_id(id); |
170 | if (!ibm_slot) { |
171 | pr_err("APLS null ACPI descriptor for slot %d\n" , id); |
172 | return -ENODEV; |
173 | } |
174 | |
175 | pr_debug("%s: set slot %d (%d) attention status to %d\n" , __func__, |
176 | ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, |
177 | (status ? 1 : 0)); |
178 | |
179 | args[0].type = ACPI_TYPE_INTEGER; |
180 | args[0].integer.value = ibm_slot->slot.slot_id; |
181 | args[1].type = ACPI_TYPE_INTEGER; |
182 | args[1].integer.value = (status) ? 1 : 0; |
183 | |
184 | kfree(objp: ibm_slot); |
185 | |
186 | stat = acpi_evaluate_integer(handle: ibm_acpi_handle, pathname: "APLS" , arguments: ¶ms, data: &rc); |
187 | if (ACPI_FAILURE(stat)) { |
188 | pr_err("APLS evaluation failed: 0x%08x\n" , stat); |
189 | return -ENODEV; |
190 | } else if (!rc) { |
191 | pr_err("APLS method failed: 0x%08llx\n" , rc); |
192 | return -ERANGE; |
193 | } |
194 | return 0; |
195 | } |
196 | |
197 | /** |
198 | * ibm_get_attention_status - callback method to get attention LED status |
199 | * @slot: the hotplug_slot to work with |
200 | * @status: returns what the LED is set to (0 or 1) |
201 | * |
202 | * Description: This method is registered with the acpiphp module as a |
203 | * callback to do the device specific task of getting the LED status. |
204 | * |
205 | * Because there is no direct method of getting the LED status directly |
206 | * from an ACPI call, we read the aPCI table and parse out our |
207 | * slot descriptor to read the status from that. |
208 | */ |
209 | static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) |
210 | { |
211 | union apci_descriptor *ibm_slot; |
212 | int id = hpslot_to_sun(slot); |
213 | |
214 | ibm_slot = ibm_slot_from_id(id); |
215 | if (!ibm_slot) { |
216 | pr_err("APLS null ACPI descriptor for slot %d\n" , id); |
217 | return -ENODEV; |
218 | } |
219 | |
220 | if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) |
221 | *status = 1; |
222 | else |
223 | *status = 0; |
224 | |
225 | pr_debug("%s: get slot %d (%d) attention status is %d\n" , __func__, |
226 | ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, |
227 | *status); |
228 | |
229 | kfree(objp: ibm_slot); |
230 | return 0; |
231 | } |
232 | |
233 | /** |
234 | * ibm_handle_events - listens for ACPI events for the IBM37D0 device |
235 | * @handle: an ACPI handle to the device that caused the event |
236 | * @event: the event info (device specific) |
237 | * @context: passed context (our notification struct) |
238 | * |
239 | * Description: This method is registered as a callback with the ACPI |
240 | * subsystem it is called when this device has an event to notify the OS of. |
241 | * |
242 | * The events actually come from the device as two events that get |
243 | * synthesized into one event with data by this function. The event |
244 | * ID comes first and then the slot number that caused it. We report |
245 | * this as one event to the OS. |
246 | * |
247 | * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will |
248 | * only re-enable the interrupt that causes this event AFTER this method |
249 | * has returned, thereby enforcing serial access for the notification struct. |
250 | */ |
251 | static void ibm_handle_events(acpi_handle handle, u32 event, void *context) |
252 | { |
253 | u8 detail = event & 0x0f; |
254 | u8 subevent = event & 0xf0; |
255 | struct notification *note = context; |
256 | |
257 | pr_debug("%s: Received notification %02x\n" , __func__, event); |
258 | |
259 | if (subevent == 0x80) { |
260 | pr_debug("%s: generating bus event\n" , __func__); |
261 | acpi_bus_generate_netlink_event(note->device->pnp.device_class, |
262 | dev_name(dev: ¬e->device->dev), |
263 | note->event, detail); |
264 | } else |
265 | note->event = event; |
266 | } |
267 | |
268 | /** |
269 | * ibm_get_table_from_acpi - reads the APLS buffer from ACPI |
270 | * @bufp: address to pointer to allocate for the table |
271 | * |
272 | * Description: This method reads the APLS buffer in from ACPI and |
273 | * stores the "stripped" table into a single buffer |
274 | * it allocates and passes the address back in bufp. |
275 | * |
276 | * If NULL is passed in as buffer, this method only calculates |
277 | * the size of the table and returns that without filling |
278 | * in the buffer. |
279 | * |
280 | * Returns < 0 on error or the size of the table on success. |
281 | */ |
282 | static int ibm_get_table_from_acpi(char **bufp) |
283 | { |
284 | union acpi_object *package; |
285 | struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; |
286 | acpi_status status; |
287 | char *lbuf = NULL; |
288 | int i, size = -EIO; |
289 | |
290 | status = acpi_evaluate_object(object: ibm_acpi_handle, pathname: "APCI" , NULL, return_object_buffer: &buffer); |
291 | if (ACPI_FAILURE(status)) { |
292 | pr_err("%s: APCI evaluation failed\n" , __func__); |
293 | return -ENODEV; |
294 | } |
295 | |
296 | package = (union acpi_object *) buffer.pointer; |
297 | if (!(package) || |
298 | (package->type != ACPI_TYPE_PACKAGE) || |
299 | !(package->package.elements)) { |
300 | pr_err("%s: Invalid APCI object\n" , __func__); |
301 | goto read_table_done; |
302 | } |
303 | |
304 | for (size = 0, i = 0; i < package->package.count; i++) { |
305 | if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { |
306 | pr_err("%s: Invalid APCI element %d\n" , __func__, i); |
307 | goto read_table_done; |
308 | } |
309 | size += package->package.elements[i].buffer.length; |
310 | } |
311 | |
312 | if (bufp == NULL) |
313 | goto read_table_done; |
314 | |
315 | lbuf = kzalloc(size, GFP_KERNEL); |
316 | pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n" , |
317 | __func__, package->package.count, size, lbuf); |
318 | |
319 | if (lbuf) { |
320 | *bufp = lbuf; |
321 | } else { |
322 | size = -ENOMEM; |
323 | goto read_table_done; |
324 | } |
325 | |
326 | size = 0; |
327 | for (i = 0; i < package->package.count; i++) { |
328 | memcpy(&lbuf[size], |
329 | package->package.elements[i].buffer.pointer, |
330 | package->package.elements[i].buffer.length); |
331 | size += package->package.elements[i].buffer.length; |
332 | } |
333 | |
334 | read_table_done: |
335 | kfree(objp: buffer.pointer); |
336 | return size; |
337 | } |
338 | |
339 | /** |
340 | * ibm_read_apci_table - callback for the sysfs apci_table file |
341 | * @filp: the open sysfs file |
342 | * @kobj: the kobject this binary attribute is a part of |
343 | * @bin_attr: struct bin_attribute for this file |
344 | * @buffer: the kernel space buffer to fill |
345 | * @pos: the offset into the file |
346 | * @size: the number of bytes requested |
347 | * |
348 | * Description: Gets registered with sysfs as the reader callback |
349 | * to be executed when /sys/bus/pci/slots/apci_table gets read. |
350 | * |
351 | * Since we don't get notified on open and close for this file, |
352 | * things get really tricky here... |
353 | * our solution is to only allow reading the table in all at once. |
354 | */ |
355 | static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, |
356 | struct bin_attribute *bin_attr, |
357 | char *buffer, loff_t pos, size_t size) |
358 | { |
359 | int bytes_read = -EINVAL; |
360 | char *table = NULL; |
361 | |
362 | pr_debug("%s: pos = %d, size = %zd\n" , __func__, (int)pos, size); |
363 | |
364 | if (pos == 0) { |
365 | bytes_read = ibm_get_table_from_acpi(bufp: &table); |
366 | if (bytes_read > 0 && bytes_read <= size) |
367 | memcpy(buffer, table, bytes_read); |
368 | kfree(objp: table); |
369 | } |
370 | return bytes_read; |
371 | } |
372 | |
373 | /** |
374 | * ibm_find_acpi_device - callback to find our ACPI device |
375 | * @handle: the ACPI handle of the device we are inspecting |
376 | * @lvl: depth into the namespace tree |
377 | * @context: a pointer to our handle to fill when we find the device |
378 | * @rv: a return value to fill if desired |
379 | * |
380 | * Description: Used as a callback when calling acpi_walk_namespace |
381 | * to find our device. When this method returns non-zero |
382 | * acpi_walk_namespace quits its search and returns our value. |
383 | */ |
384 | static acpi_status __init ibm_find_acpi_device(acpi_handle handle, |
385 | u32 lvl, void *context, void **rv) |
386 | { |
387 | acpi_handle *phandle = (acpi_handle *)context; |
388 | unsigned long long current_status = 0; |
389 | acpi_status status; |
390 | struct acpi_device_info *info; |
391 | int retval = 0; |
392 | |
393 | status = acpi_get_object_info(object: handle, return_buffer: &info); |
394 | if (ACPI_FAILURE(status)) { |
395 | pr_err("%s: Failed to get device information status=0x%x\n" , |
396 | __func__, status); |
397 | return retval; |
398 | } |
399 | |
400 | acpi_bus_get_status_handle(handle, sta: ¤t_status); |
401 | |
402 | if (current_status && (info->valid & ACPI_VALID_HID) && |
403 | (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || |
404 | !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { |
405 | pr_debug("found hardware: %s, handle: %p\n" , |
406 | info->hardware_id.string, handle); |
407 | *phandle = handle; |
408 | /* returning non-zero causes the search to stop |
409 | * and returns this value to the caller of |
410 | * acpi_walk_namespace, but it also causes some warnings |
411 | * in the acpi debug code to print... |
412 | */ |
413 | retval = FOUND_APCI; |
414 | } |
415 | kfree(objp: info); |
416 | return retval; |
417 | } |
418 | |
419 | static int __init ibm_acpiphp_init(void) |
420 | { |
421 | int retval = 0; |
422 | acpi_status status; |
423 | struct acpi_device *device; |
424 | struct kobject *sysdir = &pci_slots_kset->kobj; |
425 | |
426 | pr_debug("%s\n" , __func__); |
427 | |
428 | if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, |
429 | ACPI_UINT32_MAX, descending_callback: ibm_find_acpi_device, NULL, |
430 | context: &ibm_acpi_handle, NULL) != FOUND_APCI) { |
431 | pr_err("%s: acpi_walk_namespace failed\n" , __func__); |
432 | retval = -ENODEV; |
433 | goto init_return; |
434 | } |
435 | pr_debug("%s: found IBM aPCI device\n" , __func__); |
436 | device = acpi_fetch_acpi_dev(handle: ibm_acpi_handle); |
437 | if (!device) { |
438 | pr_err("%s: acpi_fetch_acpi_dev failed\n" , __func__); |
439 | retval = -ENODEV; |
440 | goto init_return; |
441 | } |
442 | if (acpiphp_register_attention(info: &ibm_attention_info)) { |
443 | retval = -ENODEV; |
444 | goto init_return; |
445 | } |
446 | |
447 | ibm_note.device = device; |
448 | status = acpi_install_notify_handler(device: ibm_acpi_handle, |
449 | ACPI_DEVICE_NOTIFY, handler: ibm_handle_events, |
450 | context: &ibm_note); |
451 | if (ACPI_FAILURE(status)) { |
452 | pr_err("%s: Failed to register notification handler\n" , |
453 | __func__); |
454 | retval = -EBUSY; |
455 | goto init_cleanup; |
456 | } |
457 | |
458 | ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); |
459 | retval = sysfs_create_bin_file(kobj: sysdir, attr: &ibm_apci_table_attr); |
460 | |
461 | return retval; |
462 | |
463 | init_cleanup: |
464 | acpiphp_unregister_attention(info: &ibm_attention_info); |
465 | init_return: |
466 | return retval; |
467 | } |
468 | |
469 | static void __exit ibm_acpiphp_exit(void) |
470 | { |
471 | acpi_status status; |
472 | struct kobject *sysdir = &pci_slots_kset->kobj; |
473 | |
474 | pr_debug("%s\n" , __func__); |
475 | |
476 | if (acpiphp_unregister_attention(info: &ibm_attention_info)) |
477 | pr_err("%s: attention info deregistration failed" , __func__); |
478 | |
479 | status = acpi_remove_notify_handler( |
480 | device: ibm_acpi_handle, |
481 | ACPI_DEVICE_NOTIFY, |
482 | handler: ibm_handle_events); |
483 | if (ACPI_FAILURE(status)) |
484 | pr_err("%s: Notification handler removal failed\n" , __func__); |
485 | /* remove the /sys entries */ |
486 | sysfs_remove_bin_file(kobj: sysdir, attr: &ibm_apci_table_attr); |
487 | } |
488 | |
489 | module_init(ibm_acpiphp_init); |
490 | module_exit(ibm_acpiphp_exit); |
491 | |