2 * ACPI PCI Hot Plug IBM Extension
4 * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com>
5 * Copyright (C) 2004 IBM Corp.
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.
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
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.
24 * Send feedback to <vernux@us.ibm.com>
28 #define pr_fmt(fmt) "acpiphp_ibm: " fmt
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/module.h>
33 #include <linux/kernel.h>
34 #include <acpi/acpi_bus.h>
35 #include <linux/sysfs.h>
36 #include <linux/kobject.h>
37 #include <asm/uaccess.h>
38 #include <linux/moduleparam.h>
39 #include <linux/pci.h>
44 #define DRIVER_VERSION "1.0.1"
45 #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>"
46 #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension"
49 MODULE_AUTHOR(DRIVER_AUTHOR);
50 MODULE_DESCRIPTION(DRIVER_DESC);
51 MODULE_LICENSE("GPL");
52 MODULE_VERSION(DRIVER_VERSION);
54 #define FOUND_APCI 0x61504349
55 /* these are the names for the IBM ACPI pseudo-device */
56 #define IBM_HARDWARE_ID1 "IBM37D0"
57 #define IBM_HARDWARE_ID2 "IBM37D4"
59 #define hpslot_to_sun(A) (((struct slot *)((A)->private))->sun)
61 /* union apci_descriptor - allows access to the
62 * various device descriptors that are embedded in the
65 union apci_descriptor {
89 /* struct notification - keeps info about the device
90 * that cause the ACPI notification event
93 struct acpi_device *device;
97 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);
98 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);
99 static void ibm_handle_events(acpi_handle handle, u32 event, void *context);
100 static int ibm_get_table_from_acpi(char **bufp);
101 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
102 struct bin_attribute *bin_attr,
103 char *buffer, loff_t pos, size_t size);
104 static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
105 u32 lvl, void *context, void **rv);
106 static int __init ibm_acpiphp_init(void);
107 static void __exit ibm_acpiphp_exit(void);
109 static acpi_handle ibm_acpi_handle;
110 static struct notification ibm_note;
111 static struct bin_attribute ibm_apci_table_attr = {
113 .name = "apci_table",
116 .read = ibm_read_apci_table,
119 static struct acpiphp_attention_info ibm_attention_info =
121 .set_attn = ibm_set_attention_status,
122 .get_attn = ibm_get_attention_status,
123 .owner = THIS_MODULE,
127 * ibm_slot_from_id - workaround for bad ibm hardware
128 * @id: the slot number that linux refers to the slot by
130 * Description: This method returns the aCPI slot descriptor
131 * corresponding to the Linux slot number. This descriptor
132 * has info about the aPCI slot id and attention status.
133 * This descriptor must be freed using kfree when done.
135 static union apci_descriptor *ibm_slot_from_id(int id)
138 union apci_descriptor *ret = NULL, *des;
141 size = ibm_get_table_from_acpi(&table);
142 des = (union apci_descriptor *)table;
143 if (memcmp(des->header.sig, "aPCI", 4) != 0)
146 des = (union apci_descriptor *)&table[ind += des->header.len];
147 while (ind < size && (des->generic.type != 0x82 ||
148 des->slot.slot_num != id)) {
149 des = (union apci_descriptor *)&table[ind += des->generic.len];
152 if (ind < size && des->slot.slot_num == id)
157 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);
158 memcpy(ret, des, sizeof(union apci_descriptor));
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)
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.
172 static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status)
174 union acpi_object args[2];
175 struct acpi_object_list params = { .pointer = args, .count = 2 };
177 unsigned long long rc;
178 union apci_descriptor *ibm_slot;
180 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
182 pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__,
183 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
186 args[0].type = ACPI_TYPE_INTEGER;
187 args[0].integer.value = ibm_slot->slot.slot_id;
188 args[1].type = ACPI_TYPE_INTEGER;
189 args[1].integer.value = (status) ? 1 : 0;
193 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc);
194 if (ACPI_FAILURE(stat)) {
195 pr_err("APLS evaluation failed: 0x%08x\n", stat);
198 pr_err("APLS method failed: 0x%08llx\n", rc);
205 * ibm_get_attention_status - callback method to get attention LED status
206 * @slot: the hotplug_slot to work with
207 * @status: returns what the LED is set to (0 or 1)
209 * Description: This method is registered with the acpiphp module as a
210 * callback to do the device specific task of getting the LED status.
212 * Because there is no direct method of getting the LED status directly
213 * from an ACPI call, we read the aPCI table and parse out our
214 * slot descriptor to read the status from that.
216 static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status)
218 union apci_descriptor *ibm_slot;
220 ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot));
222 if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08)
227 pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__,
228 ibm_slot->slot.slot_num, ibm_slot->slot.slot_id,
236 * ibm_handle_events - listens for ACPI events for the IBM37D0 device
237 * @handle: an ACPI handle to the device that caused the event
238 * @event: the event info (device specific)
239 * @context: passed context (our notification struct)
241 * Description: This method is registered as a callback with the ACPI
242 * subsystem it is called when this device has an event to notify the OS of.
244 * The events actually come from the device as two events that get
245 * synthesized into one event with data by this function. The event
246 * ID comes first and then the slot number that caused it. We report
247 * this as one event to the OS.
249 * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will
250 * only re-enable the interrupt that causes this event AFTER this method
251 * has returned, thereby enforcing serial access for the notification struct.
253 static void ibm_handle_events(acpi_handle handle, u32 event, void *context)
255 u8 detail = event & 0x0f;
256 u8 subevent = event & 0xf0;
257 struct notification *note = context;
259 pr_debug("%s: Received notification %02x\n", __func__, event);
261 if (subevent == 0x80) {
262 pr_debug("%s: generationg bus event\n", __func__);
263 acpi_bus_generate_netlink_event(note->device->pnp.device_class,
264 dev_name(¬e->device->dev),
265 note->event, detail);
271 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI
272 * @bufp: address to pointer to allocate for the table
274 * Description: This method reads the APLS buffer in from ACPI and
275 * stores the "stripped" table into a single buffer
276 * it allocates and passes the address back in bufp.
278 * If NULL is passed in as buffer, this method only calculates
279 * the size of the table and returns that without filling
282 * Returns < 0 on error or the size of the table on success.
284 static int ibm_get_table_from_acpi(char **bufp)
286 union acpi_object *package;
287 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
292 status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer);
293 if (ACPI_FAILURE(status)) {
294 pr_err("%s: APCI evaluation failed\n", __func__);
298 package = (union acpi_object *) buffer.pointer;
300 (package->type != ACPI_TYPE_PACKAGE) ||
301 !(package->package.elements)) {
302 pr_err("%s: Invalid APCI object\n", __func__);
303 goto read_table_done;
306 for(size = 0, i = 0; i < package->package.count; i++) {
307 if (package->package.elements[i].type != ACPI_TYPE_BUFFER) {
308 pr_err("%s: Invalid APCI element %d\n", __func__, i);
309 goto read_table_done;
311 size += package->package.elements[i].buffer.length;
315 goto read_table_done;
317 lbuf = kzalloc(size, GFP_KERNEL);
318 pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n",
319 __func__, package->package.count, size, lbuf);
325 goto read_table_done;
329 for (i=0; i<package->package.count; i++) {
331 package->package.elements[i].buffer.pointer,
332 package->package.elements[i].buffer.length);
333 size += package->package.elements[i].buffer.length;
337 kfree(buffer.pointer);
342 * ibm_read_apci_table - callback for the sysfs apci_table file
343 * @filp: the open sysfs file
344 * @kobj: the kobject this binary attribute is a part of
345 * @bin_attr: struct bin_attribute for this file
346 * @buffer: the kernel space buffer to fill
347 * @pos: the offset into the file
348 * @size: the number of bytes requested
350 * Description: Gets registered with sysfs as the reader callback
351 * to be executed when /sys/bus/pci/slots/apci_table gets read.
353 * Since we don't get notified on open and close for this file,
354 * things get really tricky here...
355 * our solution is to only allow reading the table in all at once.
357 static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj,
358 struct bin_attribute *bin_attr,
359 char *buffer, loff_t pos, size_t size)
361 int bytes_read = -EINVAL;
364 pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size);
367 bytes_read = ibm_get_table_from_acpi(&table);
368 if (bytes_read > 0 && bytes_read <= size)
369 memcpy(buffer, table, bytes_read);
376 * ibm_find_acpi_device - callback to find our ACPI device
377 * @handle: the ACPI handle of the device we are inspecting
378 * @lvl: depth into the namespace tree
379 * @context: a pointer to our handle to fill when we find the device
380 * @rv: a return value to fill if desired
382 * Description: Used as a callback when calling acpi_walk_namespace
383 * to find our device. When this method returns non-zero
384 * acpi_walk_namespace quits its search and returns our value.
386 static acpi_status __init ibm_find_acpi_device(acpi_handle handle,
387 u32 lvl, void *context, void **rv)
389 acpi_handle *phandle = (acpi_handle *)context;
391 struct acpi_device_info *info;
394 status = acpi_get_object_info(handle, &info);
395 if (ACPI_FAILURE(status)) {
396 pr_err("%s: Failed to get device information status=0x%x\n",
401 if (info->current_status && (info->valid & ACPI_VALID_HID) &&
402 (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) ||
403 !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) {
404 pr_debug("found hardware: %s, handle: %p\n",
405 info->hardware_id.string, handle);
407 /* returning non-zero causes the search to stop
408 * and returns this value to the caller of
409 * acpi_walk_namespace, but it also causes some warnings
410 * in the acpi debug code to print...
418 static int __init ibm_acpiphp_init(void)
422 struct acpi_device *device;
423 struct kobject *sysdir = &pci_slots_kset->kobj;
425 pr_debug("%s\n", __func__);
427 if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
428 ACPI_UINT32_MAX, ibm_find_acpi_device, NULL,
429 &ibm_acpi_handle, NULL) != FOUND_APCI) {
430 pr_err("%s: acpi_walk_namespace failed\n", __func__);
434 pr_debug("%s: found IBM aPCI device\n", __func__);
435 if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
436 pr_err("%s: acpi_bus_get_device failed\n", __func__);
440 if (acpiphp_register_attention(&ibm_attention_info)) {
445 ibm_note.device = device;
446 status = acpi_install_notify_handler(ibm_acpi_handle,
447 ACPI_DEVICE_NOTIFY, ibm_handle_events,
449 if (ACPI_FAILURE(status)) {
450 pr_err("%s: Failed to register notification handler\n",
456 ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
457 retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
462 acpiphp_unregister_attention(&ibm_attention_info);
467 static void __exit ibm_acpiphp_exit(void)
470 struct kobject *sysdir = &pci_slots_kset->kobj;
472 pr_debug("%s\n", __func__);
474 if (acpiphp_unregister_attention(&ibm_attention_info))
475 pr_err("%s: attention info deregistration failed", __func__);
477 status = acpi_remove_notify_handler(
481 if (ACPI_FAILURE(status))
482 pr_err("%s: Notification handler removal failed\n", __func__);
483 /* remove the /sys entries */
484 sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
487 module_init(ibm_acpiphp_init);
488 module_exit(ibm_acpiphp_exit);