/* * ACPI PCI Hot Plug IBM Extension * * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com> * Copyright (C) 2004 IBM Corp. * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Send feedback to <vernux@us.ibm.com> * */ #include <linux/init.h> #include <linux/module.h> #include <linux/kernel.h> #include <acpi/acpi_bus.h> #include <linux/sysfs.h> #include <linux/kobject.h> #include <asm/uaccess.h> #include <linux/moduleparam.h> #include "acpiphp.h" #include "pci_hotplug.h" #define DRIVER_VERSION "1.0.1" #define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" #define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" static int debug; MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE("GPL"); MODULE_VERSION(DRIVER_VERSION); module_param(debug, bool, 0644); MODULE_PARM_DESC(debug, " Debugging mode enabled or not"); #define MY_NAME "acpiphp_ibm" #undef dbg #define dbg(format, arg...) \ do { \ if (debug) \ printk(KERN_DEBUG "%s: " format, \ MY_NAME , ## arg); \ } while (0) #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) (((struct slot *)((A)->private))->acpi_slot->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 kobject *kobj, 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 = { .attr = { .name = "apci_table", .owner = THIS_MODULE, .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); 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); 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 rc; union apci_descriptor *ibm_slot; ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); dbg("%s: set slot %d (%d) attention status to %d\n", __FUNCTION__, 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)) { err("APLS evaluation failed: 0x%08x\n", stat); return -ENODEV; } else if (!rc) { err("APLS method failed: 0x%08lx\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; ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) *status = 1; else *status = 0; dbg("%s: get slot %d (%d) attention status is %d\n", __FUNCTION__, 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; dbg("%s: Received notification %02x\n", __FUNCTION__, event); if (subevent == 0x80) { dbg("%s: generationg bus event\n", __FUNCTION__); acpi_bus_generate_event(note->device, 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)) { err("%s: APCI evaluation failed\n", __FUNCTION__); return -ENODEV; } package = (union acpi_object *) buffer.pointer; if(!(package) || (package->type != ACPI_TYPE_PACKAGE) || !(package->package.elements)) { err("%s: Invalid APCI object\n", __FUNCTION__); goto read_table_done; } for(size = 0, i = 0; i < package->package.count; i++) { if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { err("%s: Invalid APCI element %d\n", __FUNCTION__, i); goto read_table_done; } size += package->package.elements[i].buffer.length; } if (bufp == NULL) goto read_table_done; lbuf = kmalloc(size, GFP_KERNEL); dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", __FUNCTION__, package->package.count, size, lbuf); if (lbuf) { *bufp = lbuf; memset(lbuf, 0, size); } 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 * @kobj: the kobject this binary attribute is a part of * @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 kobject *kobj, char *buffer, loff_t pos, size_t size) { int bytes_read = -EINVAL; char *table = NULL; dbg("%s: pos = %d, size = %zd\n", __FUNCTION__, (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; acpi_status status; struct acpi_device_info info; struct acpi_buffer info_buffer = { .length = sizeof(struct acpi_device_info), .pointer = &info, }; status = acpi_get_object_info(handle, &info_buffer); if (ACPI_FAILURE(status)) { err("%s: Failed to get device information", __FUNCTION__); return 0; } info.hardware_id.value[sizeof(info.hardware_id.value) - 1] = '\0'; if(info.current_status && (info.valid & ACPI_VALID_HID) && (!strcmp(info.hardware_id.value, IBM_HARDWARE_ID1) || !strcmp(info.hardware_id.value, IBM_HARDWARE_ID2))) { dbg("found hardware: %s, handle: %p\n", info.hardware_id.value, 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... */ return FOUND_APCI; } return 0; } static int __init ibm_acpiphp_init(void) { int retval = 0; acpi_status status; struct acpi_device *device; struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj; dbg("%s\n", __FUNCTION__); if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, ibm_find_acpi_device, &ibm_acpi_handle, NULL) != FOUND_APCI) { err("%s: acpi_walk_namespace failed\n", __FUNCTION__); retval = -ENODEV; goto init_return; } dbg("%s: found IBM aPCI device\n", __FUNCTION__); if (acpi_bus_get_device(ibm_acpi_handle, &device)) { err("%s: acpi_bus_get_device failed\n", __FUNCTION__); 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)) { err("%s: Failed to register notification handler\n", __FUNCTION__); 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_hotplug_slots_subsys.kset.kobj; dbg("%s\n", __FUNCTION__); if (acpiphp_unregister_attention(&ibm_attention_info)) err("%s: attention info deregistration failed", __FUNCTION__); status = acpi_remove_notify_handler( ibm_acpi_handle, ACPI_DEVICE_NOTIFY, ibm_handle_events); if (ACPI_FAILURE(status)) err("%s: Notification handler removal failed\n", __FUNCTION__); // remove the /sys entries if (sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr)) err("%s: removal of sysfs file apci_table failed\n", __FUNCTION__); } module_init(ibm_acpiphp_init); module_exit(ibm_acpiphp_exit);