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v3.5.6
  1/*
  2 * ACPI PCI Hot Plug IBM Extension
  3 *
  4 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
  5 * Copyright (C) 2004 IBM Corp.
  6 *
  7 * All rights reserved.
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or (at
 12 * your option) any later version.
 13 *
 14 * This program is distributed in the hope that it will be useful, but
 15 * WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 17 * NON INFRINGEMENT.  See the GNU General Public License for more
 18 * details.
 19 *
 20 * You should have received a copy of the GNU General Public License
 21 * along with this program; if not, write to the Free Software
 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 23 *
 24 * Send feedback to <vernux@us.ibm.com>
 25 *
 26 */
 27
 
 
 28#include <linux/init.h>
 29#include <linux/slab.h>
 30#include <linux/module.h>
 31#include <linux/kernel.h>
 32#include <acpi/acpi_bus.h>
 33#include <linux/sysfs.h>
 34#include <linux/kobject.h>
 35#include <asm/uaccess.h>
 36#include <linux/moduleparam.h>
 37#include <linux/pci.h>
 
 38
 39#include "acpiphp.h"
 40#include "../pci.h"
 41
 42#define DRIVER_VERSION	"1.0.1"
 43#define DRIVER_AUTHOR	"Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
 44#define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver IBM extension"
 45
 46static bool debug;
 47
 48MODULE_AUTHOR(DRIVER_AUTHOR);
 49MODULE_DESCRIPTION(DRIVER_DESC);
 50MODULE_LICENSE("GPL");
 51MODULE_VERSION(DRIVER_VERSION);
 52module_param(debug, bool, 0644);
 53MODULE_PARM_DESC(debug, " Debugging mode enabled or not");
 54#define MY_NAME "acpiphp_ibm"
 55
 56#undef dbg
 57#define dbg(format, arg...)				\
 58do {							\
 59	if (debug)					\
 60		printk(KERN_DEBUG "%s: " format,	\
 61				MY_NAME , ## arg);	\
 62} while (0)
 63
 64#define FOUND_APCI 0x61504349
 65/* these are the names for the IBM ACPI pseudo-device */
 66#define IBM_HARDWARE_ID1 "IBM37D0"
 67#define IBM_HARDWARE_ID2 "IBM37D4"
 68
 69#define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun)
 70
 71/* union apci_descriptor - allows access to the
 72 * various device descriptors that are embedded in the
 73 * aPCI table
 74 */
 75union apci_descriptor {
 76	struct {
 77		char sig[4];
 78		u8   len;
 79	} header;
 80	struct {
 81		u8  type;
 82		u8  len;
 83		u16 slot_id;
 84		u8  bus_id;
 85		u8  dev_num;
 86		u8  slot_num;
 87		u8  slot_attr[2];
 88		u8  attn;
 89		u8  status[2];
 90		u8  sun;
 91		u8  res[3];
 92	} slot;
 93	struct {
 94		u8 type;
 95		u8 len;
 96	} generic;
 97};
 98
 99/* struct notification - keeps info about the device
100 * that cause the ACPI notification event
101 */
102struct notification {
103	struct acpi_device *device;
104	u8                  event;
105};
106
107static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
108static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
109static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
110static int ibm_get_table_from_acpi(char **bufp);
111static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
112				   struct bin_attribute *bin_attr,
113				   char *buffer, loff_t pos, size_t size);
114static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
115		u32 lvl, void *context, void **rv);
116static int __init ibm_acpiphp_init(void);
117static void __exit ibm_acpiphp_exit(void);
118
119static acpi_handle ibm_acpi_handle;
120static struct notification ibm_note;
121static struct bin_attribute ibm_apci_table_attr = {
122	    .attr = {
123		    .name = "apci_table",
124		    .mode = S_IRUGO,
125	    },
126	    .read = ibm_read_apci_table,
127	    .write = NULL,
128};
129static struct acpiphp_attention_info ibm_attention_info = 
130{
131	.set_attn = ibm_set_attention_status,
132	.get_attn = ibm_get_attention_status,
133	.owner = THIS_MODULE,
134};
135
136/**
137 * ibm_slot_from_id - workaround for bad ibm hardware
138 * @id: the slot number that linux refers to the slot by
139 *
140 * Description: This method returns the aCPI slot descriptor
141 * corresponding to the Linux slot number.  This descriptor
142 * has info about the aPCI slot id and attention status.
143 * This descriptor must be freed using kfree when done.
144 */
145static union apci_descriptor *ibm_slot_from_id(int id)
146{
147	int ind = 0, size;
148	union apci_descriptor *ret = NULL, *des;
149	char *table;
150
151	size = ibm_get_table_from_acpi(&table);
152	des = (union apci_descriptor *)table;
153	if (memcmp(des->header.sig, "aPCI", 4) != 0)
154		goto ibm_slot_done;
155
156	des = (union apci_descriptor *)&table[ind += des->header.len];
157	while (ind < size && (des->generic.type != 0x82 ||
158			des->slot.slot_num != id)) {
159		des = (union apci_descriptor *)&table[ind += des->generic.len];
160	}
161
162	if (ind < size && des->slot.slot_num == id)
163		ret = des;
164
165ibm_slot_done:
166	if (ret) {
167		ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
168		memcpy(ret, des, sizeof(union apci_descriptor));
 
169	}
170	kfree(table);
171	return ret;
172}
173
174/**
175 * ibm_set_attention_status - callback method to set the attention LED
176 * @slot: the hotplug_slot to work with
177 * @status: what to set the LED to (0 or 1)
178 *
179 * Description: This method is registered with the acpiphp module as a
180 * callback to do the device specific task of setting the LED status.
181 */
182static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
183{
184	union acpi_object args[2]; 
185	struct acpi_object_list params = { .pointer = args, .count = 2 };
186	acpi_status stat; 
187	unsigned long long rc;
188	union apci_descriptor *ibm_slot;
 
189
190	ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
 
 
 
 
191
192	dbg("%s: set slot %d (%d) attention status to %d\n", __func__,
193			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
194			(status ? 1 : 0));
195
196	args[0].type = ACPI_TYPE_INTEGER;
197	args[0].integer.value = ibm_slot->slot.slot_id;
198	args[1].type = ACPI_TYPE_INTEGER;
199	args[1].integer.value = (status) ? 1 : 0;
200
201	kfree(ibm_slot);
202
203	stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
204	if (ACPI_FAILURE(stat)) {
205		err("APLS evaluation failed:  0x%08x\n", stat);
206		return -ENODEV;
207	} else if (!rc) {
208		err("APLS method failed:  0x%08llx\n", rc);
209		return -ERANGE;
210	}
211	return 0;
212}
213
214/**
215 * ibm_get_attention_status - callback method to get attention LED status
216 * @slot: the hotplug_slot to work with
217 * @status: returns what the LED is set to (0 or 1)
218 *
219 * Description: This method is registered with the acpiphp module as a
220 * callback to do the device specific task of getting the LED status.
221 * 
222 * Because there is no direct method of getting the LED status directly
223 * from an ACPI call, we read the aPCI table and parse out our
224 * slot descriptor to read the status from that.
225 */
226static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
227{
228	union apci_descriptor *ibm_slot;
 
229
230	ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
 
 
 
 
231
232	if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
233		*status = 1;
234	else
235		*status = 0;
236
237	dbg("%s: get slot %d (%d) attention status is %d\n", __func__,
238			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
239			*status);
240
241	kfree(ibm_slot);
242	return 0;
243}
244
245/**
246 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
247 * @handle: an ACPI handle to the device that caused the event
248 * @event: the event info (device specific)
249 * @context: passed context (our notification struct)
250 *
251 * Description: This method is registered as a callback with the ACPI
252 * subsystem it is called when this device has an event to notify the OS of.
253 *
254 * The events actually come from the device as two events that get
255 * synthesized into one event with data by this function.  The event
256 * ID comes first and then the slot number that caused it.  We report
257 * this as one event to the OS.
258 *
259 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
260 * only re-enable the interrupt that causes this event AFTER this method
261 * has returned, thereby enforcing serial access for the notification struct.
262 */
263static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
264{
265	u8 detail = event & 0x0f;
266	u8 subevent = event & 0xf0;
267	struct notification *note = context;
268
269	dbg("%s: Received notification %02x\n", __func__, event);
270
271	if (subevent == 0x80) {
272		dbg("%s: generationg bus event\n", __func__);
273		acpi_bus_generate_proc_event(note->device, note->event, detail);
274		acpi_bus_generate_netlink_event(note->device->pnp.device_class,
275						  dev_name(&note->device->dev),
276						  note->event, detail);
277	} else
278		note->event = event;
279}
280
281/**
282 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
283 * @bufp: address to pointer to allocate for the table
284 *
285 * Description: This method reads the APLS buffer in from ACPI and
286 * stores the "stripped" table into a single buffer
287 * it allocates and passes the address back in bufp.
288 *
289 * If NULL is passed in as buffer, this method only calculates
290 * the size of the table and returns that without filling
291 * in the buffer.
292 *
293 * Returns < 0 on error or the size of the table on success.
294 */
295static int ibm_get_table_from_acpi(char **bufp)
296{
297	union acpi_object *package;
298	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
299	acpi_status status;
300	char *lbuf = NULL;
301	int i, size = -EIO;
302
303	status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
304	if (ACPI_FAILURE(status)) {
305		err("%s:  APCI evaluation failed\n", __func__);
306		return -ENODEV;
307	}
308
309	package = (union acpi_object *) buffer.pointer;
310	if (!(package) ||
311			(package->type != ACPI_TYPE_PACKAGE) ||
312			!(package->package.elements)) {
313		err("%s:  Invalid APCI object\n", __func__);
314		goto read_table_done;
315	}
316
317	for(size = 0, i = 0; i < package->package.count; i++) {
318		if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
319			err("%s:  Invalid APCI element %d\n", __func__, i);
320			goto read_table_done;
321		}
322		size += package->package.elements[i].buffer.length;
323	}
324
325	if (bufp == NULL)
326		goto read_table_done;
327
328	lbuf = kzalloc(size, GFP_KERNEL);
329	dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
330			__func__, package->package.count, size, lbuf);
331
332	if (lbuf) {
333		*bufp = lbuf;
334	} else {
335		size = -ENOMEM;
336		goto read_table_done;
337	}
338
339	size = 0;
340	for (i=0; i<package->package.count; i++) {
341		memcpy(&lbuf[size],
342				package->package.elements[i].buffer.pointer,
343				package->package.elements[i].buffer.length);
344		size += package->package.elements[i].buffer.length;
345	}
346
347read_table_done:
348	kfree(buffer.pointer);
349	return size;
350}
351
352/**
353 * ibm_read_apci_table - callback for the sysfs apci_table file
354 * @filp: the open sysfs file
355 * @kobj: the kobject this binary attribute is a part of
356 * @bin_attr: struct bin_attribute for this file
357 * @buffer: the kernel space buffer to fill
358 * @pos: the offset into the file
359 * @size: the number of bytes requested
360 *
361 * Description: Gets registered with sysfs as the reader callback
362 * to be executed when /sys/bus/pci/slots/apci_table gets read.
363 *
364 * Since we don't get notified on open and close for this file,
365 * things get really tricky here...
366 * our solution is to only allow reading the table in all at once.
367 */
368static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
369				   struct bin_attribute *bin_attr,
370				   char *buffer, loff_t pos, size_t size)
371{
372	int bytes_read = -EINVAL;
373	char *table = NULL;
374	
375	dbg("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
376
377	if (pos == 0) {
378		bytes_read = ibm_get_table_from_acpi(&table);
379		if (bytes_read > 0 && bytes_read <= size)
380			memcpy(buffer, table, bytes_read);
381		kfree(table);
382	}
383	return bytes_read;
384}
385
386/**
387 * ibm_find_acpi_device - callback to find our ACPI device
388 * @handle: the ACPI handle of the device we are inspecting
389 * @lvl: depth into the namespace tree
390 * @context: a pointer to our handle to fill when we find the device
391 * @rv: a return value to fill if desired
392 *
393 * Description: Used as a callback when calling acpi_walk_namespace
394 * to find our device.  When this method returns non-zero
395 * acpi_walk_namespace quits its search and returns our value.
396 */
397static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
398		u32 lvl, void *context, void **rv)
399{
400	acpi_handle *phandle = (acpi_handle *)context;
401	acpi_status status; 
402	struct acpi_device_info *info;
403	int retval = 0;
404
405	status = acpi_get_object_info(handle, &info);
406	if (ACPI_FAILURE(status)) {
407		err("%s:  Failed to get device information status=0x%x\n",
408			__func__, status);
409		return retval;
410	}
411
412	if (info->current_status && (info->valid & ACPI_VALID_HID) &&
413			(!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
414			 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
415		dbg("found hardware: %s, handle: %p\n",
416			info->hardware_id.string, handle);
417		*phandle = handle;
418		/* returning non-zero causes the search to stop
419		 * and returns this value to the caller of 
420		 * acpi_walk_namespace, but it also causes some warnings
421		 * in the acpi debug code to print...
422		 */
423		retval = FOUND_APCI;
424	}
425	kfree(info);
426	return retval;
427}
428
429static int __init ibm_acpiphp_init(void)
430{
431	int retval = 0;
432	acpi_status status;
433	struct acpi_device *device;
434	struct kobject *sysdir = &pci_slots_kset->kobj;
435
436	dbg("%s\n", __func__);
437
438	if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
439			ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
440			&ibm_acpi_handle, NULL) != FOUND_APCI) {
441		err("%s: acpi_walk_namespace failed\n", __func__);
442		retval = -ENODEV;
443		goto init_return;
444	}
445	dbg("%s: found IBM aPCI device\n", __func__);
446	if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
447		err("%s: acpi_bus_get_device failed\n", __func__);
448		retval = -ENODEV;
449		goto init_return;
450	}
451	if (acpiphp_register_attention(&ibm_attention_info)) {
452		retval = -ENODEV;
453		goto init_return;
454	}
455
456	ibm_note.device = device;
457	status = acpi_install_notify_handler(ibm_acpi_handle,
458			ACPI_DEVICE_NOTIFY, ibm_handle_events,
459			&ibm_note);
460	if (ACPI_FAILURE(status)) {
461		err("%s: Failed to register notification handler\n",
462				__func__);
463		retval = -EBUSY;
464		goto init_cleanup;
465	}
466
467	ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
468	retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
469
470	return retval;
471
472init_cleanup:
473	acpiphp_unregister_attention(&ibm_attention_info);
474init_return:
475	return retval;
476}
477
478static void __exit ibm_acpiphp_exit(void)
479{
480	acpi_status status;
481	struct kobject *sysdir = &pci_slots_kset->kobj;
482
483	dbg("%s\n", __func__);
484
485	if (acpiphp_unregister_attention(&ibm_attention_info))
486		err("%s: attention info deregistration failed", __func__);
487
488	status = acpi_remove_notify_handler(
489			   ibm_acpi_handle,
490			   ACPI_DEVICE_NOTIFY,
491			   ibm_handle_events);
492	if (ACPI_FAILURE(status))
493		err("%s: Notification handler removal failed\n", __func__);
494	/* remove the /sys entries */
495	sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
496}
497
498module_init(ibm_acpiphp_init);
499module_exit(ibm_acpiphp_exit);
v4.6
  1/*
  2 * ACPI PCI Hot Plug IBM Extension
  3 *
  4 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
  5 * Copyright (C) 2004 IBM Corp.
  6 *
  7 * All rights reserved.
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation; either version 2 of the License, or (at
 12 * your option) any later version.
 13 *
 14 * This program is distributed in the hope that it will be useful, but
 15 * WITHOUT ANY WARRANTY; without even the implied warranty of
 16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 17 * NON INFRINGEMENT.  See the GNU General Public License for more
 18 * details.
 19 *
 20 * You should have received a copy of the GNU General Public License
 21 * along with this program; if not, write to the Free Software
 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 23 *
 24 * Send feedback to <vernux@us.ibm.com>
 25 *
 26 */
 27
 28#define pr_fmt(fmt) "acpiphp_ibm: " fmt
 29
 30#include <linux/init.h>
 31#include <linux/slab.h>
 32#include <linux/module.h>
 33#include <linux/kernel.h>
 
 34#include <linux/sysfs.h>
 35#include <linux/kobject.h>
 
 36#include <linux/moduleparam.h>
 37#include <linux/pci.h>
 38#include <asm/uaccess.h>
 39
 40#include "acpiphp.h"
 41#include "../pci.h"
 42
 43#define DRIVER_VERSION	"1.0.1"
 44#define DRIVER_AUTHOR	"Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
 45#define DRIVER_DESC	"ACPI Hot Plug PCI Controller Driver IBM extension"
 46
 
 47
 48MODULE_AUTHOR(DRIVER_AUTHOR);
 49MODULE_DESCRIPTION(DRIVER_DESC);
 50MODULE_LICENSE("GPL");
 51MODULE_VERSION(DRIVER_VERSION);
 
 
 
 
 
 
 
 
 
 
 
 52
 53#define FOUND_APCI 0x61504349
 54/* these are the names for the IBM ACPI pseudo-device */
 55#define IBM_HARDWARE_ID1 "IBM37D0"
 56#define IBM_HARDWARE_ID2 "IBM37D4"
 57
 58#define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun)
 59
 60/* union apci_descriptor - allows access to the
 61 * various device descriptors that are embedded in the
 62 * aPCI table
 63 */
 64union apci_descriptor {
 65	struct {
 66		char sig[4];
 67		u8   len;
 68	} header;
 69	struct {
 70		u8  type;
 71		u8  len;
 72		u16 slot_id;
 73		u8  bus_id;
 74		u8  dev_num;
 75		u8  slot_num;
 76		u8  slot_attr[2];
 77		u8  attn;
 78		u8  status[2];
 79		u8  sun;
 80		u8  res[3];
 81	} slot;
 82	struct {
 83		u8 type;
 84		u8 len;
 85	} generic;
 86};
 87
 88/* struct notification - keeps info about the device
 89 * that cause the ACPI notification event
 90 */
 91struct notification {
 92	struct acpi_device *device;
 93	u8                  event;
 94};
 95
 96static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
 97static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
 98static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
 99static int ibm_get_table_from_acpi(char **bufp);
100static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
101				   struct bin_attribute *bin_attr,
102				   char *buffer, loff_t pos, size_t size);
103static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
104		u32 lvl, void *context, void **rv);
105static int __init ibm_acpiphp_init(void);
106static void __exit ibm_acpiphp_exit(void);
107
108static acpi_handle ibm_acpi_handle;
109static struct notification ibm_note;
110static struct bin_attribute ibm_apci_table_attr = {
111	    .attr = {
112		    .name = "apci_table",
113		    .mode = S_IRUGO,
114	    },
115	    .read = ibm_read_apci_table,
116	    .write = NULL,
117};
118static struct acpiphp_attention_info ibm_attention_info =
119{
120	.set_attn = ibm_set_attention_status,
121	.get_attn = ibm_get_attention_status,
122	.owner = THIS_MODULE,
123};
124
125/**
126 * ibm_slot_from_id - workaround for bad ibm hardware
127 * @id: the slot number that linux refers to the slot by
128 *
129 * Description: This method returns the aCPI slot descriptor
130 * corresponding to the Linux slot number.  This descriptor
131 * has info about the aPCI slot id and attention status.
132 * This descriptor must be freed using kfree when done.
133 */
134static union apci_descriptor *ibm_slot_from_id(int id)
135{
136	int ind = 0, size;
137	union apci_descriptor *ret = NULL, *des;
138	char *table;
139
140	size = ibm_get_table_from_acpi(&table);
141	des = (union apci_descriptor *)table;
142	if (memcmp(des->header.sig, "aPCI", 4) != 0)
143		goto ibm_slot_done;
144
145	des = (union apci_descriptor *)&table[ind += des->header.len];
146	while (ind < size && (des->generic.type != 0x82 ||
147			des->slot.slot_num != id)) {
148		des = (union apci_descriptor *)&table[ind += des->generic.len];
149	}
150
151	if (ind < size && des->slot.slot_num == id)
152		ret = des;
153
154ibm_slot_done:
155	if (ret) {
156		ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
157		if (ret)
158			memcpy(ret, des, sizeof(union apci_descriptor));
159	}
160	kfree(table);
161	return ret;
162}
163
164/**
165 * ibm_set_attention_status - callback method to set the attention LED
166 * @slot: the hotplug_slot to work with
167 * @status: what to set the LED to (0 or 1)
168 *
169 * Description: This method is registered with the acpiphp module as a
170 * callback to do the device specific task of setting the LED status.
171 */
172static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
173{
174	union acpi_object args[2];
175	struct acpi_object_list params = { .pointer = args, .count = 2 };
176	acpi_status stat;
177	unsigned long long rc;
178	union apci_descriptor *ibm_slot;
179	int id = hpslot_to_sun(slot);
180
181	ibm_slot = ibm_slot_from_id(id);
182	if (!ibm_slot) {
183		pr_err("APLS null ACPI descriptor for slot %d\n", id);
184		return -ENODEV;
185	}
186
187	pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__,
188			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
189			(status ? 1 : 0));
190
191	args[0].type = ACPI_TYPE_INTEGER;
192	args[0].integer.value = ibm_slot->slot.slot_id;
193	args[1].type = ACPI_TYPE_INTEGER;
194	args[1].integer.value = (status) ? 1 : 0;
195
196	kfree(ibm_slot);
197
198	stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &rc);
199	if (ACPI_FAILURE(stat)) {
200		pr_err("APLS evaluation failed:  0x%08x\n", stat);
201		return -ENODEV;
202	} else if (!rc) {
203		pr_err("APLS method failed:  0x%08llx\n", rc);
204		return -ERANGE;
205	}
206	return 0;
207}
208
209/**
210 * ibm_get_attention_status - callback method to get attention LED status
211 * @slot: the hotplug_slot to work with
212 * @status: returns what the LED is set to (0 or 1)
213 *
214 * Description: This method is registered with the acpiphp module as a
215 * callback to do the device specific task of getting the LED status.
216 *
217 * Because there is no direct method of getting the LED status directly
218 * from an ACPI call, we read the aPCI table and parse out our
219 * slot descriptor to read the status from that.
220 */
221static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
222{
223	union apci_descriptor *ibm_slot;
224	int id = hpslot_to_sun(slot);
225
226	ibm_slot = ibm_slot_from_id(id);
227	if (!ibm_slot) {
228		pr_err("APLS null ACPI descriptor for slot %d\n", id);
229		return -ENODEV;
230	}
231
232	if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
233		*status = 1;
234	else
235		*status = 0;
236
237	pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__,
238			ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
239			*status);
240
241	kfree(ibm_slot);
242	return 0;
243}
244
245/**
246 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
247 * @handle: an ACPI handle to the device that caused the event
248 * @event: the event info (device specific)
249 * @context: passed context (our notification struct)
250 *
251 * Description: This method is registered as a callback with the ACPI
252 * subsystem it is called when this device has an event to notify the OS of.
253 *
254 * The events actually come from the device as two events that get
255 * synthesized into one event with data by this function.  The event
256 * ID comes first and then the slot number that caused it.  We report
257 * this as one event to the OS.
258 *
259 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
260 * only re-enable the interrupt that causes this event AFTER this method
261 * has returned, thereby enforcing serial access for the notification struct.
262 */
263static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
264{
265	u8 detail = event & 0x0f;
266	u8 subevent = event & 0xf0;
267	struct notification *note = context;
268
269	pr_debug("%s: Received notification %02x\n", __func__, event);
270
271	if (subevent == 0x80) {
272		pr_debug("%s: generating bus event\n", __func__);
 
273		acpi_bus_generate_netlink_event(note->device->pnp.device_class,
274						  dev_name(&note->device->dev),
275						  note->event, detail);
276	} else
277		note->event = event;
278}
279
280/**
281 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
282 * @bufp: address to pointer to allocate for the table
283 *
284 * Description: This method reads the APLS buffer in from ACPI and
285 * stores the "stripped" table into a single buffer
286 * it allocates and passes the address back in bufp.
287 *
288 * If NULL is passed in as buffer, this method only calculates
289 * the size of the table and returns that without filling
290 * in the buffer.
291 *
292 * Returns < 0 on error or the size of the table on success.
293 */
294static int ibm_get_table_from_acpi(char **bufp)
295{
296	union acpi_object *package;
297	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
298	acpi_status status;
299	char *lbuf = NULL;
300	int i, size = -EIO;
301
302	status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
303	if (ACPI_FAILURE(status)) {
304		pr_err("%s:  APCI evaluation failed\n", __func__);
305		return -ENODEV;
306	}
307
308	package = (union acpi_object *) buffer.pointer;
309	if (!(package) ||
310			(package->type != ACPI_TYPE_PACKAGE) ||
311			!(package->package.elements)) {
312		pr_err("%s:  Invalid APCI object\n", __func__);
313		goto read_table_done;
314	}
315
316	for (size = 0, i = 0; i < package->package.count; i++) {
317		if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
318			pr_err("%s:  Invalid APCI element %d\n", __func__, i);
319			goto read_table_done;
320		}
321		size += package->package.elements[i].buffer.length;
322	}
323
324	if (bufp == NULL)
325		goto read_table_done;
326
327	lbuf = kzalloc(size, GFP_KERNEL);
328	pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
329			__func__, package->package.count, size, lbuf);
330
331	if (lbuf) {
332		*bufp = lbuf;
333	} else {
334		size = -ENOMEM;
335		goto read_table_done;
336	}
337
338	size = 0;
339	for (i = 0; i < package->package.count; i++) {
340		memcpy(&lbuf[size],
341				package->package.elements[i].buffer.pointer,
342				package->package.elements[i].buffer.length);
343		size += package->package.elements[i].buffer.length;
344	}
345
346read_table_done:
347	kfree(buffer.pointer);
348	return size;
349}
350
351/**
352 * ibm_read_apci_table - callback for the sysfs apci_table file
353 * @filp: the open sysfs file
354 * @kobj: the kobject this binary attribute is a part of
355 * @bin_attr: struct bin_attribute for this file
356 * @buffer: the kernel space buffer to fill
357 * @pos: the offset into the file
358 * @size: the number of bytes requested
359 *
360 * Description: Gets registered with sysfs as the reader callback
361 * to be executed when /sys/bus/pci/slots/apci_table gets read.
362 *
363 * Since we don't get notified on open and close for this file,
364 * things get really tricky here...
365 * our solution is to only allow reading the table in all at once.
366 */
367static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
368				   struct bin_attribute *bin_attr,
369				   char *buffer, loff_t pos, size_t size)
370{
371	int bytes_read = -EINVAL;
372	char *table = NULL;
373
374	pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
375
376	if (pos == 0) {
377		bytes_read = ibm_get_table_from_acpi(&table);
378		if (bytes_read > 0 && bytes_read <= size)
379			memcpy(buffer, table, bytes_read);
380		kfree(table);
381	}
382	return bytes_read;
383}
384
385/**
386 * ibm_find_acpi_device - callback to find our ACPI device
387 * @handle: the ACPI handle of the device we are inspecting
388 * @lvl: depth into the namespace tree
389 * @context: a pointer to our handle to fill when we find the device
390 * @rv: a return value to fill if desired
391 *
392 * Description: Used as a callback when calling acpi_walk_namespace
393 * to find our device.  When this method returns non-zero
394 * acpi_walk_namespace quits its search and returns our value.
395 */
396static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
397		u32 lvl, void *context, void **rv)
398{
399	acpi_handle *phandle = (acpi_handle *)context;
400	acpi_status status;
401	struct acpi_device_info *info;
402	int retval = 0;
403
404	status = acpi_get_object_info(handle, &info);
405	if (ACPI_FAILURE(status)) {
406		pr_err("%s:  Failed to get device information status=0x%x\n",
407			__func__, status);
408		return retval;
409	}
410
411	if (info->current_status && (info->valid & ACPI_VALID_HID) &&
412			(!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
413			 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
414		pr_debug("found hardware: %s, handle: %p\n",
415			info->hardware_id.string, handle);
416		*phandle = handle;
417		/* returning non-zero causes the search to stop
418		 * and returns this value to the caller of
419		 * acpi_walk_namespace, but it also causes some warnings
420		 * in the acpi debug code to print...
421		 */
422		retval = FOUND_APCI;
423	}
424	kfree(info);
425	return retval;
426}
427
428static int __init ibm_acpiphp_init(void)
429{
430	int retval = 0;
431	acpi_status status;
432	struct acpi_device *device;
433	struct kobject *sysdir = &pci_slots_kset->kobj;
434
435	pr_debug("%s\n", __func__);
436
437	if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
438			ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
439			&ibm_acpi_handle, NULL) != FOUND_APCI) {
440		pr_err("%s: acpi_walk_namespace failed\n", __func__);
441		retval = -ENODEV;
442		goto init_return;
443	}
444	pr_debug("%s: found IBM aPCI device\n", __func__);
445	if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
446		pr_err("%s: acpi_bus_get_device failed\n", __func__);
447		retval = -ENODEV;
448		goto init_return;
449	}
450	if (acpiphp_register_attention(&ibm_attention_info)) {
451		retval = -ENODEV;
452		goto init_return;
453	}
454
455	ibm_note.device = device;
456	status = acpi_install_notify_handler(ibm_acpi_handle,
457			ACPI_DEVICE_NOTIFY, ibm_handle_events,
458			&ibm_note);
459	if (ACPI_FAILURE(status)) {
460		pr_err("%s: Failed to register notification handler\n",
461				__func__);
462		retval = -EBUSY;
463		goto init_cleanup;
464	}
465
466	ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
467	retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
468
469	return retval;
470
471init_cleanup:
472	acpiphp_unregister_attention(&ibm_attention_info);
473init_return:
474	return retval;
475}
476
477static void __exit ibm_acpiphp_exit(void)
478{
479	acpi_status status;
480	struct kobject *sysdir = &pci_slots_kset->kobj;
481
482	pr_debug("%s\n", __func__);
483
484	if (acpiphp_unregister_attention(&ibm_attention_info))
485		pr_err("%s: attention info deregistration failed", __func__);
486
487	status = acpi_remove_notify_handler(
488			   ibm_acpi_handle,
489			   ACPI_DEVICE_NOTIFY,
490			   ibm_handle_events);
491	if (ACPI_FAILURE(status))
492		pr_err("%s: Notification handler removal failed\n", __func__);
493	/* remove the /sys entries */
494	sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
495}
496
497module_init(ibm_acpiphp_init);
498module_exit(ibm_acpiphp_exit);