drivers/pci/hotplug/acpiphp

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This source file includes following definitions.
ibm_slot_from_id
ibm_set_attention_status
ibm_get_attention_status
ibm_handle_events
ibm_get_table_from_acpi
ibm_read_apci_table
ibm_find_acpi_device
ibm_acpiphp_init
ibm_acpiphp_exit
   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         } 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 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(&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 
 142 ibm_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 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(ibm_slot);
 185 
 186         stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", &params, &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(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(&note->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(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 
 334 read_table_done:
 335         kfree(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(&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 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(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, &current_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(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, 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         if (acpi_bus_get_device(ibm_acpi_handle, &device)) {
 437                 pr_err("%s: acpi_bus_get_device failed\n", __func__);
 438                 retval = -ENODEV;
 439                 goto init_return;
 440         }
 441         if (acpiphp_register_attention(&ibm_attention_info)) {
 442                 retval = -ENODEV;
 443                 goto init_return;
 444         }
 445 
 446         ibm_note.device = device;
 447         status = acpi_install_notify_handler(ibm_acpi_handle,
 448                         ACPI_DEVICE_NOTIFY, ibm_handle_events,
 449                         &ibm_note);
 450         if (ACPI_FAILURE(status)) {
 451                 pr_err("%s: Failed to register notification handler\n",
 452                                 __func__);
 453                 retval = -EBUSY;
 454                 goto init_cleanup;
 455         }
 456 
 457         ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL);
 458         retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr);
 459 
 460         return retval;
 461 
 462 init_cleanup:
 463         acpiphp_unregister_attention(&ibm_attention_info);
 464 init_return:
 465         return retval;
 466 }
 467 
 468 static void __exit ibm_acpiphp_exit(void)
 469 {
 470         acpi_status status;
 471         struct kobject *sysdir = &pci_slots_kset->kobj;
 472 
 473         pr_debug("%s\n", __func__);
 474 
 475         if (acpiphp_unregister_attention(&ibm_attention_info))
 476                 pr_err("%s: attention info deregistration failed", __func__);
 477 
 478         status = acpi_remove_notify_handler(
 479                            ibm_acpi_handle,
 480                            ACPI_DEVICE_NOTIFY,
 481                            ibm_handle_events);
 482         if (ACPI_FAILURE(status))
 483                 pr_err("%s: Notification handler removal failed\n", __func__);
 484         /* remove the /sys entries */
 485         sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr);
 486 }
 487 
 488 module_init(ibm_acpiphp_init);
 489 module_exit(ibm_acpiphp_exit);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/pci/hotplug/acpiphp_ibm.c

DEFINITIONS
