// SPDX-License-Identifier: GPL-2.0+ /* * ACPI PCI Hot Plug IBM Extension * * Copyright (C) 2004 Vernon Mauery * Copyright (C) 2004 IBM Corp. * * All rights reserved. * * Send feedback to * */ #define pr_fmt(fmt) "acpiphp_ibm: " fmt #include #include #include #include #include #include #include #include #include #include "acpiphp.h" #include "../pci.h" #define DRIVER_VERSION "1.0.1" #define DRIVER_AUTHOR "Irene Zubarev , Vernon Mauery " #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); MODULE_VERSION(DRIVER_VERSION); #define FOUND_APCI 0x61504349 /* these are the names for the IBM ACPI pseudo-device */ #define IBM_HARDWARE_ID1 "IBM37D0" #define IBM_HARDWARE_ID2 "IBM37D4" #define hpslot_to_sun(A) (to_slot(A)->sun) /* union apci_descriptor - allows access to the * various device descriptors that are embedded in the * aPCI table */ union apci_descriptor { struct { char sig[4]; u8 len; } header; struct { u8 type; u8 len; u16 slot_id; u8 bus_id; u8 dev_num; u8 slot_num; u8 slot_attr[2]; u8 attn; u8 status[2]; u8 sun; u8 res[3]; } slot; struct { u8 type; u8 len; } generic; }; /* struct notification - keeps info about the device * that cause the ACPI notification event */ struct notification { struct acpi_device *device; u8 event; }; static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); static void ibm_handle_events(acpi_handle handle, u32 event, void *context); static int ibm_get_table_from_acpi(char **bufp); static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t size); static acpi_status __init ibm_find_acpi_device(acpi_handle handle, u32 lvl, void *context, void **rv); static int __init ibm_acpiphp_init(void); static void __exit ibm_acpiphp_exit(void); static acpi_handle ibm_acpi_handle; static struct notification ibm_note; static struct bin_attribute ibm_apci_table_attr __ro_after_init = { .attr = { .name = "apci_table", .mode = S_IRUGO, }, .read = ibm_read_apci_table, .write = NULL, }; static struct acpiphp_attention_info ibm_attention_info = { .set_attn = ibm_set_attention_status, .get_attn = ibm_get_attention_status, .owner = THIS_MODULE, }; /** * ibm_slot_from_id - workaround for bad ibm hardware * @id: the slot number that linux refers to the slot by * * Description: This method returns the aCPI slot descriptor * corresponding to the Linux slot number. This descriptor * has info about the aPCI slot id and attention status. * This descriptor must be freed using kfree when done. */ static union apci_descriptor *ibm_slot_from_id(int id) { int ind = 0, size; union apci_descriptor *ret = NULL, *des; char *table; size = ibm_get_table_from_acpi(&table); if (size < 0) return NULL; des = (union apci_descriptor *)table; if (memcmp(des->header.sig, "aPCI", 4) != 0) goto ibm_slot_done; des = (union apci_descriptor *)&table[ind += des->header.len]; while (ind < size && (des->generic.type != 0x82 || des->slot.slot_num != id)) { des = (union apci_descriptor *)&table[ind += des->generic.len]; } if (ind < size && des->slot.slot_num == id) ret = des; ibm_slot_done: if (ret) { ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); if (ret) memcpy(ret, des, sizeof(union apci_descriptor)); } kfree(table); return ret; } /** * ibm_set_attention_status - callback method to set the attention LED * @slot: the hotplug_slot to work with * @status: what to set the LED to (0 or 1) * * Description: This method is registered with the acpiphp module as a * callback to do the device specific task of setting the LED status. */ static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) { union acpi_object args[2]; struct acpi_object_list params = { .pointer = args, .count = 2 }; acpi_status stat; unsigned long long rc; union apci_descriptor *ibm_slot; int id = hpslot_to_sun(slot); ibm_slot = ibm_slot_from_id(id); if (!ibm_slot) { pr_err("APLS null ACPI descriptor for slot %d\n", id); return -ENODEV; } pr_debug("%s: set slot %d (%d) attention status to %d\n", __func__, ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, (status ? 1 : 0)); args[0].type = ACPI_TYPE_INTEGER; args[0].integer.value = ibm_slot->slot.slot_id; args[1].type = ACPI_TYPE_INTEGER; args[1].integer.value = (status) ? 1 : 0; kfree(ibm_slot); stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); if (ACPI_FAILURE(stat)) { pr_err("APLS evaluation failed: 0x%08x\n", stat); return -ENODEV; } else if (!rc) { pr_err("APLS method failed: 0x%08llx\n", rc); return -ERANGE; } return 0; } /** * ibm_get_attention_status - callback method to get attention LED status * @slot: the hotplug_slot to work with * @status: returns what the LED is set to (0 or 1) * * Description: This method is registered with the acpiphp module as a * callback to do the device specific task of getting the LED status. * * Because there is no direct method of getting the LED status directly * from an ACPI call, we read the aPCI table and parse out our * slot descriptor to read the status from that. */ static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) { union apci_descriptor *ibm_slot; int id = hpslot_to_sun(slot); ibm_slot = ibm_slot_from_id(id); if (!ibm_slot) { pr_err("APLS null ACPI descriptor for slot %d\n", id); return -ENODEV; } if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) *status = 1; else *status = 0; pr_debug("%s: get slot %d (%d) attention status is %d\n", __func__, ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, *status); kfree(ibm_slot); return 0; } /** * ibm_handle_events - listens for ACPI events for the IBM37D0 device * @handle: an ACPI handle to the device that caused the event * @event: the event info (device specific) * @context: passed context (our notification struct) * * Description: This method is registered as a callback with the ACPI * subsystem it is called when this device has an event to notify the OS of. * * The events actually come from the device as two events that get * synthesized into one event with data by this function. The event * ID comes first and then the slot number that caused it. We report * this as one event to the OS. * * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will * only re-enable the interrupt that causes this event AFTER this method * has returned, thereby enforcing serial access for the notification struct. */ static void ibm_handle_events(acpi_handle handle, u32 event, void *context) { u8 detail = event & 0x0f; u8 subevent = event & 0xf0; struct notification *note = context; pr_debug("%s: Received notification %02x\n", __func__, event); if (subevent == 0x80) { pr_debug("%s: generating bus event\n", __func__); acpi_bus_generate_netlink_event(note->device->pnp.device_class, dev_name(¬e->device->dev), note->event, detail); } else note->event = event; } /** * ibm_get_table_from_acpi - reads the APLS buffer from ACPI * @bufp: address to pointer to allocate for the table * * Description: This method reads the APLS buffer in from ACPI and * stores the "stripped" table into a single buffer * it allocates and passes the address back in bufp. * * If NULL is passed in as buffer, this method only calculates * the size of the table and returns that without filling * in the buffer. * * Returns < 0 on error or the size of the table on success. */ static int ibm_get_table_from_acpi(char **bufp) { union acpi_object *package; struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; acpi_status status; char *lbuf = NULL; int i, size = -EIO; status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); if (ACPI_FAILURE(status)) { pr_err("%s: APCI evaluation failed\n", __func__); return -ENODEV; } package = (union acpi_object *) buffer.pointer; if (!(package) || (package->type != ACPI_TYPE_PACKAGE) || !(package->package.elements)) { pr_err("%s: Invalid APCI object\n", __func__); goto read_table_done; } for (size = 0, i = 0; i < package->package.count; i++) { if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { pr_err("%s: Invalid APCI element %d\n", __func__, i); goto read_table_done; } size += package->package.elements[i].buffer.length; } if (bufp == NULL) goto read_table_done; lbuf = kzalloc(size, GFP_KERNEL); pr_debug("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", __func__, package->package.count, size, lbuf); if (lbuf) { *bufp = lbuf; } else { size = -ENOMEM; goto read_table_done; } size = 0; for (i = 0; i < package->package.count; i++) { memcpy(&lbuf[size], package->package.elements[i].buffer.pointer, package->package.elements[i].buffer.length); size += package->package.elements[i].buffer.length; } read_table_done: kfree(buffer.pointer); return size; } /** * ibm_read_apci_table - callback for the sysfs apci_table file * @filp: the open sysfs file * @kobj: the kobject this binary attribute is a part of * @bin_attr: struct bin_attribute for this file * @buffer: the kernel space buffer to fill * @pos: the offset into the file * @size: the number of bytes requested * * Description: Gets registered with sysfs as the reader callback * to be executed when /sys/bus/pci/slots/apci_table gets read. * * Since we don't get notified on open and close for this file, * things get really tricky here... * our solution is to only allow reading the table in all at once. */ static ssize_t ibm_read_apci_table(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t pos, size_t size) { int bytes_read = -EINVAL; char *table = NULL; pr_debug("%s: pos = %d, size = %zd\n", __func__, (int)pos, size); if (pos == 0) { bytes_read = ibm_get_table_from_acpi(&table); if (bytes_read > 0 && bytes_read <= size) memcpy(buffer, table, bytes_read); kfree(table); } return bytes_read; } /** * ibm_find_acpi_device - callback to find our ACPI device * @handle: the ACPI handle of the device we are inspecting * @lvl: depth into the namespace tree * @context: a pointer to our handle to fill when we find the device * @rv: a return value to fill if desired * * Description: Used as a callback when calling acpi_walk_namespace * to find our device. When this method returns non-zero * acpi_walk_namespace quits its search and returns our value. */ static acpi_status __init ibm_find_acpi_device(acpi_handle handle, u32 lvl, void *context, void **rv) { acpi_handle *phandle = (acpi_handle *)context; unsigned long long current_status = 0; acpi_status status; struct acpi_device_info *info; int retval = 0; status = acpi_get_object_info(handle, &info); if (ACPI_FAILURE(status)) { pr_err("%s: Failed to get device information status=0x%x\n", __func__, status); return retval; } acpi_bus_get_status_handle(handle, ¤t_status); if (current_status && (info->valid & ACPI_VALID_HID) && (!strcmp(info->hardware_id.string, IBM_HARDWARE_ID1) || !strcmp(info->hardware_id.string, IBM_HARDWARE_ID2))) { pr_debug("found hardware: %s, handle: %p\n", info->hardware_id.string, handle); *phandle = handle; /* returning non-zero causes the search to stop * and returns this value to the caller of * acpi_walk_namespace, but it also causes some warnings * in the acpi debug code to print... */ retval = FOUND_APCI; } kfree(info); return retval; } static int __init ibm_acpiphp_init(void) { int retval = 0; acpi_status status; struct acpi_device *device; struct kobject *sysdir = &pci_slots_kset->kobj; pr_debug("%s\n", __func__); if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, ibm_find_acpi_device, NULL, &ibm_acpi_handle, NULL) != FOUND_APCI) { pr_err("%s: acpi_walk_namespace failed\n", __func__); retval = -ENODEV; goto init_return; } pr_debug("%s: found IBM aPCI device\n", __func__); if (acpi_bus_get_device(ibm_acpi_handle, &device)) { pr_err("%s: acpi_bus_get_device failed\n", __func__); retval = -ENODEV; goto init_return; } if (acpiphp_register_attention(&ibm_attention_info)) { retval = -ENODEV; goto init_return; } ibm_note.device = device; status = acpi_install_notify_handler(ibm_acpi_handle, ACPI_DEVICE_NOTIFY, ibm_handle_events, &ibm_note); if (ACPI_FAILURE(status)) { pr_err("%s: Failed to register notification handler\n", __func__); retval = -EBUSY; goto init_cleanup; } ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); return retval; init_cleanup: acpiphp_unregister_attention(&ibm_attention_info); init_return: return retval; } static void __exit ibm_acpiphp_exit(void) { acpi_status status; struct kobject *sysdir = &pci_slots_kset->kobj; pr_debug("%s\n", __func__); if (acpiphp_unregister_attention(&ibm_attention_info)) pr_err("%s: attention info deregistration failed", __func__); status = acpi_remove_notify_handler( ibm_acpi_handle, ACPI_DEVICE_NOTIFY, ibm_handle_events); if (ACPI_FAILURE(status)) pr_err("%s: Notification handler removal failed\n", __func__); /* remove the /sys entries */ sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr); } module_init(ibm_acpiphp_init); module_exit(ibm_acpiphp_exit);