491 lines · c
1// SPDX-License-Identifier: GPL-2.0+2/*3 * ACPI PCI Hot Plug IBM Extension4 *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: " fmt15 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 34MODULE_AUTHOR(DRIVER_AUTHOR);35MODULE_DESCRIPTION(DRIVER_DESC);36MODULE_LICENSE("GPL");37MODULE_VERSION(DRIVER_VERSION);38 39#define FOUND_APCI 0x6150434940/* 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 the47 * various device descriptors that are embedded in the48 * aPCI table49 */50union apci_descriptor {51 struct {52 char sig[4];53 u8 len;54 } header;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 device75 * that cause the ACPI notification event76 */77struct notification {78 struct acpi_device *device;79 u8 event;80};81 82static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status);83static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status);84static void ibm_handle_events(acpi_handle handle, u32 event, void *context);85static int ibm_get_table_from_acpi(char **bufp);86static 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);89static acpi_status __init ibm_find_acpi_device(acpi_handle handle,90 u32 lvl, void *context, void **rv);91static int __init ibm_acpiphp_init(void);92static void __exit ibm_acpiphp_exit(void);93 94static acpi_handle ibm_acpi_handle;95static struct notification ibm_note;96static 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};104static 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 hardware113 * @id: the slot number that linux refers to the slot by114 *115 * Description: This method returns the aCPI slot descriptor116 * corresponding to the Linux slot number. This descriptor117 * has info about the aPCI slot id and attention status.118 * This descriptor must be freed using kfree when done.119 */120static 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(&table);127 if (size < 0)128 return NULL;129 des = (union apci_descriptor *)table;130 if (memcmp(des->header.sig, "aPCI", 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 142ibm_slot_done:143 if (ret) {144 ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL);145 if (ret)146 memcpy(ret, des, sizeof(union apci_descriptor));147 }148 kfree(table);149 return ret;150}151 152/**153 * ibm_set_attention_status - callback method to set the attention LED154 * @slot: the hotplug_slot to work with155 * @status: what to set the LED to (0 or 1)156 *157 * Description: This method is registered with the acpiphp module as a158 * callback to do the device specific task of setting the LED status.159 */160static 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(ibm_slot);185 186 stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &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 status199 * @slot: the hotplug_slot to work with200 * @status: returns what the LED is set to (0 or 1)201 *202 * Description: This method is registered with the acpiphp module as a203 * 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 directly206 * from an ACPI call, we read the aPCI table and parse out our207 * slot descriptor to read the status from that.208 */209static 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 else223 *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(ibm_slot);230 return 0;231}232 233/**234 * ibm_handle_events - listens for ACPI events for the IBM37D0 device235 * @handle: an ACPI handle to the device that caused the event236 * @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 ACPI240 * 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 get243 * synthesized into one event with data by this function. The event244 * ID comes first and then the slot number that caused it. We report245 * 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 will248 * only re-enable the interrupt that causes this event AFTER this method249 * has returned, thereby enforcing serial access for the notification struct.250 */251static 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(¬e->device->dev),263 note->event, detail);264 } else265 note->event = event;266}267 268/**269 * ibm_get_table_from_acpi - reads the APLS buffer from ACPI270 * @bufp: address to pointer to allocate for the table271 *272 * Description: This method reads the APLS buffer in from ACPI and273 * stores the "stripped" table into a single buffer274 * it allocates and passes the address back in bufp.275 *276 * If NULL is passed in as buffer, this method only calculates277 * the size of the table and returns that without filling278 * in the buffer.279 *280 * Returns < 0 on error or the size of the table on success.281 */282static 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(ibm_acpi_handle, "APCI", NULL, &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 334read_table_done:335 kfree(buffer.pointer);336 return size;337}338 339/**340 * ibm_read_apci_table - callback for the sysfs apci_table file341 * @filp: the open sysfs file342 * @kobj: the kobject this binary attribute is a part of343 * @bin_attr: struct bin_attribute for this file344 * @buffer: the kernel space buffer to fill345 * @pos: the offset into the file346 * @size: the number of bytes requested347 *348 * Description: Gets registered with sysfs as the reader callback349 * 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 */355static 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(&table);366 if (bytes_read > 0 && bytes_read <= size)367 memcpy(buffer, table, bytes_read);368 kfree(table);369 }370 return bytes_read;371}372 373/**374 * ibm_find_acpi_device - callback to find our ACPI device375 * @handle: the ACPI handle of the device we are inspecting376 * @lvl: depth into the namespace tree377 * @context: a pointer to our handle to fill when we find the device378 * @rv: a return value to fill if desired379 *380 * Description: Used as a callback when calling acpi_walk_namespace381 * to find our device. When this method returns non-zero382 * acpi_walk_namespace quits its search and returns our value.383 */384static 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(handle, &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, ¤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 stop409 * and returns this value to the caller of410 * acpi_walk_namespace, but it also causes some warnings411 * in the acpi debug code to print...412 */413 retval = FOUND_APCI;414 }415 kfree(info);416 return retval;417}418 419static 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, ibm_find_acpi_device, NULL,430 &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(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(&ibm_attention_info)) {443 retval = -ENODEV;444 goto init_return;445 }446 447 ibm_note.device = device;448 status = acpi_install_notify_handler(ibm_acpi_handle,449 ACPI_DEVICE_NOTIFY, ibm_handle_events,450 &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(sysdir, &ibm_apci_table_attr);460 461 return retval;462 463init_cleanup:464 acpiphp_unregister_attention(&ibm_attention_info);465init_return:466 return retval;467}468 469static 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(&ibm_attention_info))477 pr_err("%s: attention info deregistration failed", __func__);478 479 status = acpi_remove_notify_handler(480 ibm_acpi_handle,481 ACPI_DEVICE_NOTIFY,482 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(sysdir, &ibm_apci_table_attr);487}488 489module_init(ibm_acpiphp_init);490module_exit(ibm_acpiphp_exit);491